The Story of an Industrial Revolution · Impossible Dream I n 1979, Elf Aquitaine* and the Institut...

The Story of an Industrial Revolution

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HORIZONTAL DRILLING

The R&D Department and Drilling & Wells Division of Total Exploration & Production would like to thank the following contributors, without whom this book would not have been possible:

Bertrand BacaudJacques BosioEmmanuelle BouvinPhilippe CoffinGuillaume DuloutNicolas DurancePhilippe EsselAndré JourdanBenoît LudotDaniel PlatheyPatrick SorriauxAlain SpreuxRoland VighettoChristian Wittrisch

Acknowledgments

THE 90° TURN HORIZONTAL DRILLINGTHE 90° TURN

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Dreaming the Impossible Dream

In 1979, Elf Aquitaine* and the Institut Français du Pétrole** (IFP) launched a research and development program

christened “FORHOR, Horizontal Drilling to Improve Hydrocarbon Production.” The goal was to prove that something most oil and gas players of the time considered a pipe dream was in fact scientifically and technically feasible. The project was allocated a budget of FRF 60 million (€9.16 million today) over the five-year period from 1979 to 1984.

Until that time, reservoirs had only been developed using vertical and directional wells. FORHOR set out to test whether horizontal wells could make it easier to recover oil and gas and improve well productivity. The idea did not come out of nowhere. As early as the 1930s, reservoir engineers and drillers in France and beyond were already talking about this alternative to conventional drilling. The second oil shock spurred them into action. Between 1978 and 1981, energy prices tripled. The Iran-Iraq War, the recession in the United States and growing world demand combined to push optimized production front and center. Horizontal drilling promised to take the industry in a new direction.

With FORHOR, Elf Aquitaine and the IFP leapt ahead of the pack. They were the first to take the idea off the drawing board and attempt “the impossible” — drilling at 90°. In 1980, the R&D team successfully completed the first horizontal well, Lacq 90, and confirmed the technique’s viability a year later with Lacq 91. The two partners had delivered a major innovation that revolutionized

Drill string being prepared for lowering into the Lacq 91 horizontal well

* 2000: TotalFina/Elf Aquitaine merger.**2010: Institut Français du Pétrole (IFP) renamed IFP Énergies Nouvelles (IFPEN).

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INTRO

practices in the oil and gas industry. Between 1980 and 1992, Elf Aquitaine drilled some 50 horizontal wells in the company’s fields, more than half of them in Rospo Mare in the Adriatic Sea.

Horizontal drilling makes it possible to de-velop reservoirs that contain highly viscous oil, are relatively thin, vertically fractured or fairly impermeable, or that have an active aquifer capable of quickly flooding a verti-cal well. Without this innovative technique, Italy’s huge offshore Rospo Mare field could never have been developed. But where vertical wells had failed, horizontal wells succeeded. Years later, horizontal drilling would also allow the development of other major resources, notably shale deposits that would have been impossible to produce without this revolutionary technique.

To retrace the history of horizontal drilling from the 1930s to the present is to relive an amazing human adventure. Part history, part memoir, this book tells the story of the project’s key players — the bold, pioneering engineers, site managers and executives who believed in it — in their own words. Together they made horizontal drilling a reality, overcame the challenges and refined the technique. They also did everything in their power to win over the naysayers — those who said it would never work, who claimed it would be prohibitively expensive. Thanks to these passionate trailblazers, in less than ten years the once impossible dream of horizontal drilling became an industry standard, in an R&D feat beyond compare.

“The Timer, the Timer”Philippe Coffin, drilling engineer recruited by Elf Aquitaine in 1981“It’s easy to be sure you’re on the right trajectory in vertical drilling, much less so when you start to approach the horizontal. Back in 1981, we didn’t have sensors connected to computers. We had to make do with what we had on hand. The only instrument we had was a magnetic single-shot, a sort of miniature camera with a compass. To check the direction and hole angle, we had to stop drilling and lower the magnetic single-shot to the bottom of the well, take a ‘snapshot,’ haul the instrument back up with a cable and read the negative to see where the needle was pointing. It took at least an hour each time! A timer set before the descent down the drillpipe turned the camera on and off and controlled how long the film was exposed. This was usually the responsibility of the toolpusher, who would carefully orchestrate every step of the process, yelling ‘the timer, the timer’ for fear of triggering the instrument on the way down! The first wells were drilled using this hands-on approach, until measurement while drilling (MWD) was developed, and there again Elf Aquitaine was a pioneer.”

INTRO

The Early Days of Horizontal Drilling, First Hand

“A Generation of Sideways Drillers”Bernard Astier, FORHOR’s first project managerIn the early 1980s, this pioneering engineer was nicknamed the “prone driller.” He was responsible for Lacq 90, the first horizontal test well, drilled in the Lacq Superior reservoir in southwestern France. The well was 1,036 meters long, with a 270-meter horizontal section. Success! Eight years later, still ready to tackle the most extreme challenges, he coordinated the drilling of the first horizontal well in a natural gas reservoir, Zuidwal in the Netherlands. In September 1993, in an interview in HC Magazine, a monthly published by Elf Hydrocarbures, he admitted that “a feeling of anxiety hung over the project, and the entire team breathed a sigh of relief when they realized they had accomplished something unprecedented.”

The Lacq field

“The Challenge Was Irresistible”André Jourdan, drilling engineer recruited by Elf Aquitaine in 1969“In 1980, I was offered the position of project manager for the horizontal drilling R&D project. When the head of R&D told me that I was going to drill at 90°, I kept my mouth shut but I had my doubts — and I wasn’t the only one! I had spent the previous ten years, from 1969 to 1979, drilling vertical wells, first in Canada and then in Libya. I had no idea of the challenges involved in directional drilling. I remember meeting Bernard Astier in Pau, just before he left for China. He was a true believer, brimming with enthusiasm. I was 40 years old and was eager to pull off this insane professional challenge. My predecessor left me a year’s worth of studies and the first tangible result: the Lacq test well. I said to myself, ‘Why not?’ I wrote the report on the first well for the joint Elf Aquitaine/IFP project management committee and recommended drilling a second horizontal well in Lacq to ‘prove that the success of the first well wasn’t just a fluke.’ A year later, this new well, deeper and with a longer horizontal section, confirmed the technique’s feasibility. We had realized every reservoir engineer’s dream: drilling through a reservoir horizontally to improve its productivity. A decade later, the drilling industry had no more doubts: barring a good reason to drill vertically, every well was horizontal.”

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Multilateral well (1990 to present)Horizontal well (1980 to present)

“Tapping the Unreachable”Philippe Essel, drilling and completion engineer“I was hired by Elf Aquitaine in 1992. Since then, I have mostly helped to drill directional wells, and even some horizontal wells. When I arrived, it was already the standard for development wells. There had to be a good reason for deviating from standard practice and drill a vertical well instead! Between 1990 and 2000, we drilled deeper and deeper, and wells got longer and longer. In 1999, Total set a world record with an 11,184-meter extended reach well in Argentina. We have now reached a threshold. With current techniques, it will be hard to exceed 13,000 meters of offset. In 2016 research is being conducted on several disruptive technologies, including replacing steel pipes with lighter aluminum ones, pipe-in-pipe technology and multilateral wells. In the future, these advances may make it possible to drill multi-target wells with 20,000 meters of offset to tap fields currently considered unreachable or uneconomical.”

In the early 1980s, horizontal drilling was a hot button issue. Some managers were for, others

against. Critics voiced doubts about the project’s technical feasibility and said that it was unacceptably expensive compared to vertical drilling. While prototypes bore them out — the cost was ten times higher than that of a vertical well — technological advances quickly closed the gap. Ten years after the start of the adventure, a horizontal well cost only 30 to 40% more than

a vertical one, but produced two to three times as much oil. Wherever horizontal drilling was used, it increased production enough to more than offset the extra investment. In practice, horizontal wells increased oil production from Canada’s Pelican Lake and Winter fields six-fold between 1986 and 1990 and boosted output from Italy’s Rospo Mare field from 200 to 1,200 cubic meters a day (source: Oil & Gas Journal).

FOR OR AGAINST?

Vertical well (19th century) Directional well (1930 to present)

Changing well configurations

INTRO INTRO

“RSM-6d on Rospo Mare, a World First”Patrick Sorriaux, geological engineer recruited in January 1982 (Boussens Geology Laboratory)“In 1980, Elf Aquitaine was sponsoring my thesis on karst. The Rospo Mare field was my primary topic of study. The reservoir is a paleokarst in a Cretaceous carbonate platform. In 1975, the offshore Rospo Mare 1 discovery well was drilled in the Adriatic in a water depth of 80 meters. Appraisal of the find was almost complete, with several vertical wells already extensively cored and sampled. Using horizontal wells far from the water table to intercept karstified vertical fractures and improve production was an idea whose time had come. To test the concept, the affiliate began a pilot phase with the RSM-4 vertical well, the RSM-5d directional well and the RSM-6d horizontal well. That was the one that became the world’s first producing offshore horizontal well.”

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by the Cultural Revolution. It appeared that horizontal drilling had reached a dead end. Too complicated! Too expensive! For Jacques Bosio, Deputy R&D Director for E&P, “These failures were due to the choice of site, not the technique.”

The Soviet CatalystTo understand the development of horizontal drilling, we need to visit the U.S.S.R. of the 1940s and the work of Alexander Grigoryan. In 1941, this visionary young petroleum engineer, a recent graduate of the Azerbaijan Industrial Institute, led the region’s first horizontal drilling endeavor, to a depth of 1,700 meters. He intuitively brought a major innovation to the project: the turbodrill, developed a few years earlier by another Soviet engineer, Matvei Alkunovich Kapelyushnikov, who studied at the Tomsk Technical Institute in Siberia. The concept was simple but ingenious. The turbo drilling motor was installed just above the bit and was activated by the flow of drilling mud. The use of a downhole motor meant that the drill bit didn’t have to be turned from the surface, as in rotary drilling. The result was faster, more efficient drilling, cutting the time required by 60% and the energy used by 30%. With high hopes, the Soviets continued to develop the technology. In 1968, they set a new record in Siberia with the longest well yet drilled, 2,507 meters, which included a 632-meter horizontal section. But it wasn’t exactly a success, with production volumes falling short of expectations. Subsequent analysis

The terms horizontal well and horizontal drilling may seem narrow. In fact, they include all

of the horizontal or subhorizontal production technologies and systems used in a producing reservoir. Horizontal wells can be categorized according to the drilling technique used:

> Long- and medium-radius wells require several hundred meters to turn from the vertical to the horizontal. They use now-standardized equipment. The

horizontal sections of these wells are several hundred meters in length and use conventional drill bit diameters.

> Short-radius wells require special equipment to reach the horizontal in just a few dozen meters. The horizontal sections are short, under 100 meters, and have a small hole size. The trajectory is hard to control. This technique is used chiefly to sidetrack a horizontal well from an existing vertical well.

WHAT IS HORIZONTAL DRILLING?

showed that the Soviets did not know how to direct the horizontal sections so that they passed through the biggest oil and gas pay.

The engineers were ordered to change tack. Oil and gas producers were forced to aban-don horizontal drilling and return their focus to vertical technology. At a time of rising en-ergy prices, the U.S.S.R. wanted to increase its exports to bring in foreign currency. The message was clear: drill as many vertical wells as possible to boost production.

This was a disappointment to Grigoryan, who had been appointed to head the All-Union Scientific Research Institute for Drilling Technology in Moscow; he still fervently believed in horizontal drilling.

Disillusioned, his work now monitored and restricted, Grigoryan formed ties with the Institut Français du Pétrole. This was one of the catalysts for the FORHOR R&D program launched jointly by the IFP and Elf Aquitaine in 1979.

LOOKING BACKLOOKING BACK

“Launching the FORHOR R&D program wasn’t enough in itself. We also

had to convince the teams of its merits. There was a lot of resis-tance to horizontal drilling. More due to the industry’s mindset than to the technical challenges. In the late 1970s, drilling engineers were convinced that the maximum pos-sible angle for a well was 70°. Reservoir engineers, on the other hand, did not believe that the extra cost of drilling horizontally could be offset by enhanced production. Changing mindsets by 90° proved to be much trickier than changing the direction of the wellbores!”

Jacques BosioDeputy R&D Director for E&P in 1979

Approaching the horizontal was tough

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Before 1920, drillers would never have dreamed of straying from the vertical. The first directional wells were drilled

in the early 1930s. In an anecdotal but telling observation, Mark Mau and Henry Edmundson write in Groundbreakers that in the United States: “Most of the early directional wells were probably illegal, drilled by unscrupulous operators who were trying to steal from their neighbors.” In Texas, investigators assisted by the Texas Rangers uncovered and shut in more than 380 wells of this type in the Woodbine Formation.The crooked drillers used a simple method. They bought or leased wells with declining production abandoned by the big oil companies. When production ended, they installed a derrick for well maintenance and production enhancement. At that point, all they had to do was install a whipstock to go looking for oil offset from the initial target.

In 1970, Directional Drilling Relied on Tried and True Methodology.

> A bottomhole assembly (BHA) is com-posed of a drill bit, a hydraulic downhole motor, and a bent sub. The deviation was initiated up to plus or minus 10° in the chosen direction.

> A rotary drill was used to continue the deviation. The positioning of stabilizers in the bottomhole assembly and the drill configuration (weight and rotation) were crucial to directing the trajectory.

> The trajectory was managed by mea-suring directional parameters at the bottom of the well: angle, azimuth, and positioning of the bent sub.

> Several tools were devoted to moni-toring the directional drilling process, chiefly the magnetic single-shot and cable steering tool systems that pre-vented rotation. In the 1970s, MWD did not yet exist.

2. The State of the Art Prior to the FORHOR R&D Program’s Launch

Offshore DrillingIncreased demand for energy following World War II led oil producers to take offshore resources more seriously. Initially, drilling rigs were permanent structures, and mobile barges transported equipment from one well to the next. Increasing production meant drilling more wells and building more rigs, which was both expensive and time-consuming. Directional drilling made it possible to bundle wells onto a single platform and thus cut costs. A breakthrough came in the early 1960s with the start of deepwater drilling. “Next generation” drilling rigs made their debut. Dynamic positioning systems — with sensors and thrusters placed around the ship — allowed vessels to stay put.

Up to 70°!Directional drilling enjoyed robust develop-ment both onshore and offshore in the late 1960s, to meet surface logistic needs or adapt to the reservoir configuration. The idea was to reach a target offset from the vertical of the drilling rig. This could be necessary for a variety of reasons: operating multiple wells, drilling under the seabed from the coast, operating in a fault zone, exploiting an inaccessible site, dealing with stratigraphic traps, conducting relief operations, drilling under salt domes, hole straightening and deviation with abandonment of the hole are just some. These wells never exceeded a deviation of 70°, the “wall” beyond which standard equipment and conventional drilling techniques no longer worked because frictional forces offset gravity.

The WhipstockThis entirely legal tool was invented by John H. Eastman in 1929 to reach viscous offshore oil from onshore sites without having to build new rigs. In 1934, he was considered the expert in directional dril-ling, having executed the first relief well to control a blowout by drilling a lateral out-let to an existing well, called a side track. From that day forward, drillers saw direc-tional drilling in a new light and sought to learn what they could. The whipstock made it possible to start changing direction.

LOOKING BACKLOOKING BACK

Drill string of the past

Bending force (weight)

LeverBending

limit

StabilizerWeight on bit

Stabilizer

Stabilizer

ASCENT STABILIZATION DESCENT

Pendulum

Pendulum effect

Gravity

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A Wall at 90°

The Difficulties Inherent in Gravity Acting Perpendicularly to the Well Axis

> Transporting and removing cuttings. > Well wall strength. > Installation of instruments usually

raised and lowered by cable. > Lowering operations and cementing

wellbore casings. > Transfer of weight to the bit.

Low estimate = Too short

High estimate = Crash

Real reservoir depth

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Drillers were categorical: it was impossible to adapt directional drilling techniques to drill horizontally. The difficulties involved in tight angles and the precision needed to reach the target would require the de-velopment of new methods. A number of major hurdles would have to be overcome.

Managing the Angle’s Inevitable DeclineThe force that the drill bit applies to the rock it drills is at its highest when drilling vertically; when turning horizontal, it diminishes and is then cancelled out by another parasitic force — this one perpendicular to the drilling axis — whose amplitude peaks at 90° in the horizontal well. This parasitic force causes increased friction between the drilling assembly and the walls of the well and pushes the tool to the bottom of the borehole. This configuration increases the pendulum effect of the assembly, i.e. its tendency to pull to the low side of the hole, causing the angle to decrease.

Reaching the Target with Precision In conventional directional drilling, the target is represented by a point of impact located at the center of a circle with a diameter of 100 to 200 meters within a horizontal plane. This target is roughly comparable to a helicopter landing pad. To stick the landing, the azimuth and angle naturally need to be controlled throughout the descent, but it doesn’t really matter if the angle at which the drill bit arrives differs from the initial plan. Horizontal drilling is a different story. The target is a long cylinder

whose height is around 20 times smaller than diameter of the target circle mentioned above. The driller must not only thread the entry to the cylinder, but also follow the cylinder along hundreds of meters without deviating from it. The process is more like landing an airplane. The final trajectory is known, and the airplane cannot stray from it without taking risks. The same is true of approaching a reservoir. At every instant, the parameters — depth, distance from the point of impact, and angle — must match the preset coordinates. Any deviation from the planned trajectory would require an extremely complex correction owing to the tight angle.

“Until the 1980s, it was more complicated and more costly to drill a

directional well than a vertical one. Controlling the direction of the drill bit required numerous maneuvers and frequent stoppages to change the lower portion of the assembly — the part that made the ‘deviation’ possible — and to take direction measurements. No one ever imagined or wanted to risk exceeding the limit of a 60° to 70° angle. Too many headaches down that road! And then, as luck

would have it, one day all of the conditions came together for a handful of drillers to take up the challenge. There were two big catalysts. One, we had our sights set on the Rospo Mare reservoir, which had to be produced but whose yield from vertical drilling was next to nothing. And two, we had the perfect site — the Lacq field — where we could drill test wells. From there, everything fell into place for us to break records and pull off a technological exploit.”

André Jourdan Horizontal drilling project manager from 1980

All the conditions were ripe to launch an R&D program

SPOTLIGHT

LOOKING BACK

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2.ELF AQUITAINE AND THE INSTITUT FRANÇAIS DU PÉTROLE, FROM INSPIRATION TO IMPLEMENTATION

1. The FORHOR R&D Program

2. Potential Applications for Horizontal Drilling

niques to boost productivity and increase the amount of hydrocarbons extracted from onshore and offshore reservoirs. The strate-gic goal was to make it possible to develop new fossil fuel resources.

FORHOR focused on four topics: reservoir methodology, drilling, electric logging, and well equipment and production start-up.

The Goals > Confirm the technical feasibility of hori-

zontal drilling. > Develop an innovative technology to pro-

duce reserves considered inaccessible at that time, the early 1980s.

> Enhance reservoir productivity. > Prove that the additional cost of horizontal

drilling was more than offset by enhanced productivity.

1. The FORHOR R&D Program

ELF AQUITAINE AND THE IFP, FROM INSPIRATION TO IMPLEMENTATION

Over five years, the program carried out several commercial-scale tests.

From May to June 1980: Lacq 90, Western Europe’s first horizontal well, was drilled to a depth of 670 meters, intersecting the reservoir for 270 meters, of which 100 horizontally.

March and April 1981: Lacq 91 was drilled; 1,250 meters in length, it intersected the reservoir for 470 meters, of which 370 horizontally.

The discovery of the huge Rospo Mare oil field in Italy in the mid-1970s served as a catalyst for innovation. The

compact rock of the reservoir had a network of large fractures containing viscous oil and experienced significant water intrusions. Vertical and directional wells were not suited to this kind of configuration. With the world mired in a global oil-price shock, Elf Aquitaine had to face the facts: there was no way of extracting this lode of black gold for Europe, barring a stroke of genius.

That stroke of genius came from a reservoir engineer in the Production Division. Herbert Reiss, who specialized in fractured reservoirs, was convinced that the only way to produce the oil was to intersect as many of the vertical fractures as possible using a horizontal well. The idea was a bold departure from conventional wisdom. But, as it turned out, the skeptical drillers were more than able to meet the “far-fetched” challenge. An intrigued Jacques Bosio, then Deputy R&D Director for E&P, took the idea to the Institut Français du Pétrole (IFP). In what proved to be a visionary move, Elf Aquitaine and the IFP launched the “FORHOR, Horizontal Drilling to Improve Hydrocarbon Production” research and development program.

Improving production was on many minds in 1979, when the second oil shock was still front and center on the global stage. Both the European Economic Community (EEC) and France’s Hydrocarbon Support Fund (known by the French acronym FSH) funded the five-year program to develop new tech-

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February to March 1982: Lacq 91 was the first horizontal well out-fitted with selective production equipment.

January to April 1982: The first offshore horizontal well was drilled, in Italy’s Rospo Mare field. Reaching a depth of 1,380 meters, it intersected the reservoir for 606 meters, of which 380 horizontally.

June 1983: The CLU 110 horizontal well was drilled in the Castéra-Lou field to improve produc-tivity in the Brèche de Garlin formation. A new record was set when it reached a depth of 2,891 meters.

2. Potential Applications for Horizontal Drilling

The reservoir studies conducted as part of FORHOR identified the circumstances suited to horizontal

drilling. Specific numerical models were developed to pinpoint the displacement of the oil/water interface and the improvement in sweeping oil from the reservoir. As early as

1980, horizontal drilling was recommended for fractured reservoirs, thin homogenous reservoirs, and to improve multiphase production: water or gas breakthrough, oil sweeping, and enhanced oil recovery. The potential was enormous. New fields were now there for the taking around the world.

Horizontal well applications

Aquifer

Clay

Oil or gas reservoir

Fractured reservoir

Thin reservoir

Multiphase production

“The FORHOR R&D program began in 1979, the year I joined the IFP after three years at

Schlumberger working on well logging. That experience allowed me to come up with a game-changing innovation, SIMPHOR, an instrumentation and measurement system for horizontal wells. We had to figure out a way to trip the logging tool within a horizontal well. Lowering it by cable, as was typically done in a vertical well, became impossible at an angle greater than 55° or 60°, when the force of gravity was cancelled out by the friction of the tool

against the wellbore. So I figured we should lower the logging tools using the drillpipe, by attaching them to a support including a male connector with seven wires. A female connector linked to a wireline carried the electric current. We then ran into a second problem: the wireline prevented us from adding new drillpipes. So I designed a specific connector with a sideways slot that it could pass through. And it worked. The first tests took place in March 1981 on Lacq 91. FORHOR was extraordinarily fertile ground for innovation and risk-taking.”

Christian WittrischResearch engineer in the IFP’s Geophysics & Instruments Department since 1979

It was an amazing adventure. We had to invent everything, especially when it came to well logging.

ELF AQUITAINE AND THE IFP, FROM INSPIRATION TO IMPLEMENTATIONELF AQUITAINE AND THE IFP, FROM INSPIRATION TO IMPLEMENTATION

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3.A TEAM EFFORT

1. Working Across Specializations

2. Team Successes, Team Awards Galore

Fractured ReservoirsHorizontal drilling offered an obvious ad-vantage: whereas a vertical or deviated well would encounter few or no fractures, a hori-zontal well would intersect several and thus be much more productive. In effect, it is via this network of fractures, which can be few and far between, that oil flows to the well.

Thin Homogeneous Oil ReservoirsHere again, a comparison tips the scales in favor of horizontal drilling. In the case of a vertical well, penetration is limited by the thickness of the layer (typically 2 to 20 meters). In the case of a horizontal well, penetration at the time could exceed 500 meters. While the increase in productivity was not proportional to the length of the well, it was easily three to five times higher. And even though horizontal drilling was slightly more expensive, studies showed that it would take at least four vertical wells to equal the production of a single horizontal well (source: Elf Aquitaine, 1983).

Improving Multiphase Production SystemsHorizontal wells have a decisive edge when it comes to sweeping the reservoir with water or gas, especially when the oil is highly viscous. Water inflow is accelerated when the flow is unstable, but the steady flow between horizontal wells allows for a more uniform progression of the oil-water or oil-gas interface, which is particularly advantageous at the start of production. Horizontal wells offer two advantages in combating water and gas inflow. First, the producing section of the well can be located far from the unwanted fluid. The length of this section means that less oil is drawn from the reservoir per linear meter, thereby enhancing the uniformity of the oil-fluid interface. Second, the distance from the interface means that “clean” oil — without water or gas breakthrough that could destabilize the flow in the well and ultimately reduce output — can be produced for longer.

Water drive reservoir produced using horizontal wells

Aquifer

Oil reservoir

Water drive

ELF AQUITAINE AND THE IFP, FROM INSPIRATION TO IMPLEMENTATION

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1. Working Across Specializations

Setting the target and trajectory for drilling is a team effort. From the outset of the horizontal drilling

adventure, the project group put their faith in a multidisciplinary approach. Several professional specializations were enlisted, including reservoir engineering, drilling, drilling fluids, well completion and production. Synergies also came into play between the partners — the IFP and Elf Aquitaine — and with the oil services providers. “The early days of horizontal drilling saw close cooperation with directional drilling specialist Top Services (now Anadrill-Schlumberger). That company’s Engineering Director, Pierre Armessen, was consulted on all of the initial wells, from Lacq 90 to Rospo Mare,” remembers André Jourdan.

People are the catalysts for innovation. When the teams ran into hitches on the ground, they were the ones who adapted

the horizontal drilling tools to improve performance, inventing measurement while drilling (MWD), logging while drilling (LWD) and SIMPHOR, the instrumentation and measurement system used in horizontal wells. When reservoir engineers decided to produce the drainage area via horizontal wells, they set an “entry point” or “target” — the all-important cylinder — in the reservoir. Determining the trajectory the driller had to follow to it was one of the most vital aspects of preparations. On the ground, the trajectory had to take into account not only the requirements specific to the drilling operation, but also any changes in the reservoir’s configuration. The driller then had to determine whether increased production and drainage over the medium and long term would be enough to make the extra cost of a horizontal well worthwhile.

2. Team Successes, Team Awards Galore

Offshore Energy Center Hall of Fame 2014: Three Times OverIn its 2014 Hall of Fame presentation, the Offshore Energy Center recognized two former Elf employees, André Jourdan as an Industry Pioneer and Jacques Bosio as a Drilling Technology Pioneer: Horizon-tal Drilling. It also recognized Total as a Drilling Technology Pioneer: Horizontal Drilling.

SIMPHOR and the 2011 Chéreau-Lavet Engineer-Inventor Award, FranceChristian Wittrisch, the research engineer in the IFP’s Geophysics & Instruments Department who worked on the FORHOR R&D program, received the 2011 Chéreau-Lavet Award for designing and developing the SIMPHOR instrumentation and measurement system for horizontal wells. This technologically innovative solution made downhole conventional logging possible in high-angle and horizontal wells. By the end of the 1980s, all oil companies had adopted SIMPHOR. Horizontal drilling became the industry standard for producing larger volumes over a longer time period and enhancing the recovery factor for oil and gas trapped in a geological formation.Since 1981, the IFP has filed more than 60 patents in France and 55 in the United States. In 2011, earnings and royalties from SIMPHOR amounted to €22 million.

Technology Pioneer Award, 2011The award was made by the Offshore Energy Center in recognition of Total’s development of measurement while drilling (MWD).

SPE Drilling Engineering Award, Amsterdam, 1991The Society of Petroleum Engineers (SPE) recognized the advances made in horizon-tal drilling and the teamwork that took the idea from the drawing board to a working technology. Two men were honored for their ability to inspire: André Jourdan on the drilling side and Herbert Reiss on the reservoir side. In 1990, André Jourdan was named Distinguished Lecturer for 1990 and 1991 on the topic “Horizontal Drilling: Is It Worth It?”

Innovative Company, 1987The Fondation du Brevet d’Invention recognized the IFP for its contributions to developing SIMPHOR.

Société Générale Energy Award, 1983This distinction recognized “Horizontal Drilling to Develop New Energy Resources.”

André Jourdan is presented with the Industry Pioneer Award by the Chairman of the Offshore Energy Center Hall of Fame Committee in Houston on September 20, 2014.

SPE Drilling Engineering Award, 1991: André Jourdan, left, and Herbert Reiss, right.

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4.HORIZONTAL DRILLING TECHNOLOGY TAKES ITS FIRST STEPS

1. Legendary Tools

2. The Drill String

1. Legendary Tools

Monitoring the Angle, Azimuth and Direction of the Bent Sub Taking Photos Every 10 Meters with the Magnetic Single-Shot “The timer, the timer!” Those who were there when the first horizontal wells were drilled still remember the stress and anxiety of using the magnetic single-shot camera, the timed descent and ascent and the missed photos. Borrowed from vertical drilling, this was the only tool that drillers had to monitor the directional parameters of the first horizontal wells in the early 1980s. The principle was a very simple one. A magnetic single-shot was a miniature camera equipped with a floating, spherical, transparent compass. It was lowered by cable to take a photo every 90 to 120 meters in the vertical section of a well, much more frequently (every 10 meters) in the directional and horizontal sections. A timer was set before the tool began its descent into the borehole, to control when the camera took the photo and how long the film was exposed. Once developed on the surface, the photo showed the part of the compass that was directly in the camera’s line of sight when the measurement was taken. Problems in the field included frequent drilling interruptions, periodic measurements, and “photo shoots” that took too long. It took between an hour and an hour and a half to get a single image, not

counting times when an accidental misfire or underexposed photo meant starting the whole process over. Beyond an angle of 65°, the magnetic single-shot could not descend by force of gravity alone. It had to be driven hydraulically by pumping drilling mud into the drillpipe.

A Step Forward: The AZINTAC Real-Time System Developed by the IFP, AZINTAC was an instrument that could be read instantly and directly to monitor directional measurements in real time. Three accelerometers measured the gravitational field vector along a trihedral’s three axes, while three magnetometers measured the strength of the Earth’s magnetic field. These six measurements were multiplexed, encoded and continuously transmitted to the surface via a single cable that also powered the sensors, electronics and logging tool.A computer above ground interpreted the measurements and displayed the directional data. The cable prevented the assembly from rotating, meaning a downhole motor had to be used. This offered big advantages for making tough azimuth corrections requiring numerous bit angle measurements. On the drill floor, a repeater enabled the directional driller to control the trajectory of the borehole.

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Measurement While Drilling (MWD), a Wireless FirstStemming from research begun by Elf Aquitaine in 1965, this tool was introduced by Teleco Oilfield Services in 1978. For many years, it was the sole wireless directional measurement system compatible with all drilling operations requiring rotation of the drill string.

> The TELECO tool consisted of a direc-tional sensor made up of accelerome-ters and magnetometers, an encoder, a transmitter and a generator housed in a nonmagnetic drill collar. It was an inte-gral part of the bottomhole assembly.

> To take a directional measurement, the drill string’s rotation was halted for 90 seconds, while mud continued to circu-late. It then took two and a half minutes to transmit the data collected to the sur-face. This was done by pulses encoded in the drilling mud, the same way DSL and optical fiber work today, but with a data speed of a few bits per second, compared with 1 billion for fiber.

> This system was used for Lacq 91 and on Rospo Mare to steer trajectories up to angles of 70° to 80°, but it was still too large to be used in the horizontal section.

The TELECO system Logging While Drilling (LWD)LWD measures both directional parameters and the basic characteristics of the formations encountered, mainly resistivity and the presence of clay (through naturally occurring gamma radiation). Formation surveying is particularly important during the reservoir approach phase so that drillers can adhere to the planned geological sections while downhole. LWD made it possible to adjust the “landing” trajectory once the rock markers signaling the top of the reservoir had been identified. Data is just as important in the well’s horizontal section. Any indication of a change in the aspect and characteristics of the rock — its facies — signaling an exit from the reservoir or the presence of water or gas allows the driller to change course quickly. The MWD/LWD sensor is typically located around 10 meters behind the bit; thus, it is necessary to anticipate the assembly’s reaction to a change in direction. This is where the directional driller’s experience and instinct play an important role.These systems are also used to:

> Identify changes in reservoir character-istics, such as porosity and fluids.

> Detect faults early enough to adjust to potential problems.

> Pinpoint fluid boundaries. > Define coring and casing points earlier.

In the mid-1970s, Gearhart-Owen and Teleco Oilfield Services, to which Elf Aquitaine granted

licenses, “developed” MWD. In 1978, following promising tests in the Gulf of Mexico, Teleco Oilfield Services introduced the first commercial version. In the wake of that launch, a number of other oilfield services companies — Schlumberger, Sperry-Sun, Exlog and Eastman Christensen — also began to research and engineer MWD and LWD systems.

Maximum needle valve displacement

Vibration dampener

Needle valve

Needle valve control

Turbine Generator

Nonmagnetic drill collar

Power cable Centralizer

Sensor and electronics assembly

Vibration dampener

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Get to the Target More QuicklyTélépilote, an Adjustable Bent SubIn directional drilling, a downhole motor topped by a bent sub was typically used to kick off the deviation or to correct the azimuth for angles of less than 50° to 55°. Previously, reaching the target required ad-justing the angle of the bent sub multiple times, which meant raising the drill string to the surface to attach the right bent sub for the next segment.The Advantages of Télépilote A variable angle bent sub that could be adjusted from the surface, Télépilote was composed of two cylindrical units — a fixed upper unit and a mobile lower unit — linked by a common shaft. The centerline of the lower cylinder was at an angle from the other main parts. Increasing the flow of mud caused the cylinder to rotate.While a good idea on paper, the system de-veloped by the R&D team failed to win over the teams in the field. Its performance was unpredictable, dependent upon the drilling rig’s hydraulic capacity, and thus required very accurate estimates of mud flow and density through the end of the phase. It was abandoned.

Surveying the ReservoirSIMPHOR Brings Next-Generation Logging Invented by Christian Wittrisch, a research engineer in the IFP’s Geophysics & Instruments Department, the SIMPHOR instrumentation and measurement system for horizontal wells was the FORHOR research team’s choice as early as 1981 for logging in high-angle and horizontal wells. The quality of the logs was equivalent to that of conventional wells. The equipment was used for the Lacq 91 test well: the logs covered a horizontal section 470 meters in length at a depth of 670 meters. They were executed in three 150-meter sections with recording while tripping both in and out. A first.How It Works

> A logger and its casing are attached to the tool support. The assembly is screwed to the end of the first drillpipe and lowered to the logging area by adding drillpipes to the string.

> An electrical connection runs between the tool support and the power cable inside the drillpipe.

> A side-entry sub guides the cable from inside the drillpipe outside in the vertical or low-angle section of the borehole.

> Moving the drillpipe makes it possible to log the measurement or the completion operation.

Trip logs obtained by raising and lowering drillpipes

Télépilote operating principle

Top module centerline

Piston centerline

Bottom module centerline

Logging truck

Added pipe or production tubing

Cable

Side-entry sub window connection

Deviation departure

Weight

Cable

Logging probe

Trip log

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2. The Drill String

The drill string includes all of the tubulars that tie the drill bit to the surface, and thus transmit rotation and weight. It consists of two parts.

The Bottomhole Assembly This determines and measures deviation and directional behavior. There are two main types of assembly, rotary and downhole mo-tors. The bottomhole assembly is as com-pact as possible: one or two nonmagnetic drill collars, MWD/LWD tools, stabilizers, and a motor, depending on the set-up. This eliminates unnecessary weight. > A rotary assembly uses both

gravitational pull and the equipment’s flexibility, with the entire unit reacting like a beam on a support subjected to an axial force, with the weight on the bit. Changes in the weight and the rotary speed can alter the directional behavior of the bottomhole assembly. Finding the right assembly was a process of trial and error. The ORPHÉE 2D software developed by Elf/Total made it possible to optimize BHA selection. But if the assembly wasn’t working, it had to be pulled back to the surface so that the stabilizers could be repositioned. There are three types of assembly: build assemblies using a slow or fast build rate, holding assemblies using stabilizers, and dropping assemblies (pendulum principle). Each configuration uses a different placement of stabilizers. The MWD/LWD tool is located close to the bit.

Bottomhole assembly

Rotary build assembly

Rotary build assembly with

cracker

Stabilized rotary assembly

from the helical gear pump concept developed by René Moineau, have seen major technical advancements, evolving from a basic vertical motor paired with a bent sub into the recently developed steerable systems. These motors can be configured to be slow or fast, short or long, with or without stabilizers, bent or double-bent. Each configuration corresponds to a specific use, for example building angle or stabilization, or adapting to different terrain and thus different drill bits. The downhole measuring instruments are mounted above the motor, so are around nine meters farther away from the bit than in a rotary assembly.

The Drilling AssemblyThe drilling assembly connects the bottomhole assembly to the surface. In vertical drilling, the heavy components (drill collar) are placed above the drill bit. The neutral point is maintained in the drill collar, the bottom portion of which works under compression while the upper portion is under tension. So the drill string operates under tension, as it should.In high-angle and horizontal wells, this equipment needs to be in the low-angle or vertical portion to maintain enough weight. This is a reversed assembly. There is pressure on the drillpipes, causing them to operate under compression and leading to the risk of buckling.Studies have determined the critical axial force beyond which buckling occurs for different drilling and pipe diameters. This

Motor with bent housing

Bent sub, motor and bent

housing

has made it possible to design specific drillpipe configurations that combine conventional pipes with so-called heavy weight drillpipes (HWDP) of various grades.

FRICTION AND TORQUE

One of the major problems of high-angle and horizontal wells is that much of the drill string rests on the bottom of the borehole, causing friction that can reach a critical point when increasing the assembly’s torque and the tension on the hook during trips. So friction has to be assessed and mitigated. At the time, FRISSON software was used to accurately estimate the extent of the friction. Experience has shown that minimizing friction requires optimizing the mud’s coefficient of friction and the deviation profile and reducing the weight of the assembly’s “horizontal” section.

There is no ideal profile for minimizing both trip friction and torque. However, through experience, engineers have determined more favorable profiles when choosing the position and value of gradients for building angle.

> In downhole motor assemblies, turbines with a stator, such as the one designed by French manufacturer Neyrpic, are hardly ever used anymore in conventional drilling, and even less so in horizontal drilling. In short configurations, they were used along with a bent sub to kick off the deviation. Only positive displacement motors (PDM), derived

Bent sub, motor and bent

housing

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1. Two Test Wells in the Lacq Basin in the Early 1980s5.

TRADE-OFFS IN THE FIELD

1. Two Test Wells in the Lacq Basin in the Early 1980s

Drill, Observe and SolveIn 1979, Bernard Astier, an engineer in Elf Aquitaine’s Drilling Research Department, was named head of the FORHOR project. For a year, he led and coordinated feasibility studies and technical trials at the Boussens lab. “We started from scratch. Once we chose the Lacq site, we tried to determine the best trajectory profile for the Lacq 90 well, then we calculated the exact coordinates for installing the various casings.” The R&D team was deliberately given a free hand so that the project managers could make the best decisions in light of the circumstances, in response to how the trajectory and drilling were going generally, especially beyond the 70° point. “We managed operations day by day and meter by meter. Team members were enthusiastic, excited by the slightly wild challenge of drilling horizontally. Some of us didn’t get much sleep during the 44 days it took to drill Lacq 90 in May and June 1980.” The result was worth a few sleepless nights: the borehole was 1,086 meters long and intersected the reservoir for 270 meters, including 100 meters horizontally. A worldwide first!

In 1980, in the Lacq Superior oil field, the team successfully drilled the first well with a substantial horizontal section within an oil reservoir. Oil producers’ “impossible dream” was no longer impossible.

The FORHOR R&D team drilled two horizontal test wells, Lacq 90 and Lacq 91, to prove the technology.

Lacq 90, a Worldwide FirstSite SelectionLocated at the foot of the Pyrenees moun-tains, the Lacq basin — more specifically the Lacq Superior oil field — was the team’s pick for drilling. The site had everything the project team was looking for:

> A license had already been granted by the government’s Service des Mines.

> Elf Aquitaine held a 100% interest in the license.

> A proven safety system was in place. > Logistics were simplified by the fact that

Elf Aquitaine and oil services companies, including Top Services, had administra-tive offices there.

> The reservoir’s characteristics made renewed production a possibility with Lacq 90.

The Goals > Confirm that horizontal drilling was,

generally, feasible in a known reservoir at a shallow depth.

> Identify any new problems and analyze them.

> Find the technique’s limits by giving site personnel free rein.

> Limit the use of the downhole motor–bent sub method in favor of rotary assemblies.

> Determine the overall cost.

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Lacq 90 well profile

The Results > 44 days to drill 1,086 meters. > 270 meters within the reservoir, includ-

ing 100 meters horizontally. > Use and adaptation of conventional

methods. > Three core samples drilled horizontally. > Highly satisfactory control over the

trajectory. > Excellent performance by the well once

in production. > Reasonable drilling time for a well this

challenging. > Effective supervision.

Confirming the Technology and Reducing CostsBarely a year after its first horizontal drilling success, the FORHOR R&D program spudded a second test well to confirm and improve the technology and to drill an even longer horizontal section. Bernard Astier, who had been transferred to China, passed the torch to André Jourdan. “Bernard gave me all the Lacq 90 drilling reports. I wrote up our findings and presented them to the FORHOR management committee in Paris. I ended by suggesting we drill a second well to prove that the first one hadn’t been a fluke.” The “ayes” had it. They needed to master the technique before tackling the project’s real target, Rospo Mare. The second test well, Lacq 91, was begun in March 1981 and went even better than the first. Delivered in 42 days, it was 1,250 meters long, with 470 meters in the reservoir. The horizontal section was 370 meters, nearly four times longer than for Lacq 90.

LACQ 91The Goals

> Confirm the methods used for Lacq 90. > Push operations and tests even further, to

the point of taking some calculated risks. > Improve methods, particularly for bottom-

hole logging and production equipment.

The Results > 42 days to drill 1,250 meters. > 470 meters within the reservoir, includ-

ing 370 meters horizontally. > Five core samples drilled horizontally. > The drilling trajectory was a near-

perfect replication of Lacq 90, which proved that the trajectory could be controlled in familiar territory.

> SIMPHOR logs were recorded in the open horizontal borehole, a world first.

> After production start-up, significant water inflow required a well intervention.

Core samples drilled horizontally in the Lacq 91 borehole with a turbocore bit

PRODUCTION GAINS CONFIRMED ON CASTÉRA-LOU

The Castéra-Lou horizontal well was drilled in mid-1983 with the goals of increasing production and proving the technique at greater depth. The target was at 3,000 meters. “While we were drilling the horizontal section, there was a significant inflow of oil that took us over two days to bring under control by weighting up the mud. That was a first in horizontal drilling,” remembers Philippe Coffin, the well’s drilling supervisor.

From the start, the well’s production was four times greater than that of a vertical well. Through 1999, the performance continued to impress: the well was still producing more than its vertical counterparts, and its cumulative production remained nearly four times greater. And this was despite the fact that a fracture caused a significant inflow of water. Furthermore, the well’s depth had not had a negative impact on the drilling process. These results considerably broadened the technique’s potential applications. Engineers were already considering greater lengths and extended reach.

Verti

cal d

epth

in m

eter

s

Horizontal displacement in meters

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1. The R&D Team Tackles Offshore Drilling6.

ROSPO MARE 6, ANOTHER WORLD FIRST

1. The R&D Team Tackles Offshore Drilling

2. Obstacles and Technical Choices

was put together, and they drilled Rospo Mare 6 in 71 days, between January and April 1982. The well was 2,316 meters long with a horizontal section of 370 meters at a depth of 1,370 meters. The borehole intersected the reservoir over 606 meters. Another success! The well was soon producing 3,000 barrels per day, 20 times more than adjacent vertical wells, raising recoverable reserves from next to zero to 450 million barrels. Enough to save the Italian affiliate and allow it grow. Rospo Mare, Europe’s largest deposit in terms of reserves, quickly became the world’s first oil field produced using horizontal wells. This confirmed the company’s leadership in the technology, which was starting to attract interest from Big Oil. By 1992, 27 wells were producing. The high cost of the first well—three times that of a vertical well—was brought down to a ratio of 1.2.

In late 1981, Rospo Mare’s production was next to nothing, and the Italian affiliate, Elf Idrocarburi Italiana, was on the brink of

collapse. Vertical drilling of this enormous, highly fractured karstified reservoir was getting nowhere. Horizontal drilling was the only hope. “You have to remember that from 1979 on, using the technology on Rospo Mare on a commercial scale was the driving force for Elf Aquitaine’s R&D efforts,” notes André Jourdan. The FORHOR program’s successful Lacq 90 and Lacq 91 onshore wells paved the way. The R&D team now faced a new challenge. This time, they had to drill offshore, in the Adriatic Sea off Pescara, and produce a uniquely thin reservoir containing very viscous oil. These were much more complicated conditions than the Lacq formation.Jacques Bosio, the Deputy R&D Director, convinced management to go for it. A team

PROMONTORIO DEL GARGANIO

ROSPO MARE

ADRIATIC SEA

PESCARA

ORTONA

VASTO

TERMOLI

VICO DEL GARGANOVIESTE

SAN SEVERO

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2. Obstacles and Technical Choices

On Lacq, FORHOR “only” needed to demonstrate horizontal drilling’s technical feasibility. The stakes were

much higher for Rospo Mare 6. This was no test well. The R&D team needed to produce a reservoir whose output was declining. They wanted to prove that the technology could give the Italian reservoir a shot at real production. They had to adjust the roadmap to optimize drilling in a complex karstified geological formation that was heterogeneous and fractured; get as much data as they could about the reservoir’s geology by stepping up core sampling and logging; and lay the groundwork for a quality completion phase. After 71 days of drilling, measurement and completion took an additional 13 days. Eight core samples were drilled and a complete set of drilling measurements was taken using the new SIMPHOR method before completion with an uncemented slotted liner.

Rospo Mare block diagram ROSPO MARE, MADE FOR HORIZONTAL PRODUCTION

- In the production zone, permeability solely linked to the vertical fractures.

- A waterdrive reservoir with occur-rences of water inflow.

- An offshore location where the extended-reach lateral departures made possible by horizontal wells were an advantage.

Rospo Mare field, horizontal well vertical profiling “One incident made a big

impression on me as a young geologist. The core

samples were analyzed in Pescara, Elf Aquitaine’s operational base on the Adriatic. I was working with geologist Henri Soudet, who had started studies on the appraisal wells. For Rospo Mare 6, six of the eight core samples were taken from the reservoir. In the other two, we found the green argillaceous limestone characteristic of the cap rock rather than the karstified pure limestone of the reservoir. I concluded that the last section of drilling had exited the reservoir. The bosses were skeptical, and yet… A few days later, biostratigraphy by the Boussens lab confirmed that the samples dated to the Oligo-Miocene. The paleokarst cap rock and reservoir had a much more varied morphology than expected, with the paleovalleys and sinkholes characteristic of karst morphology.

To get a feeling for what conditions were like at the time, remember that there was no geosteering and no 3D seismic to select the well location. So the logs recorded at the bottom of the borehole validated our hypothesis and allowed us to hone our interpretation by revealing a second depression. Because our drilling friends used a claw-type core bit that allowed for precise placement when taking core samples, we were able to

conduct more in-depth tests back in the lab using a slanted gutter system to replicate their original positioning. Drawing analogies with what we already knew about karsts, we were able to create an interpretive cross-section of RSM 6d. People still remember that cross-section, and it has been reprinted in numerous publications.

In 1986, the Sismage® software suite developed by Noomane Keskes made its debut. 3D seismic definitively confirmed the varied morphology of the karst reservoir’s cap rock, which had sinkhole-like circular depressions and valleys. Obviously, we had to understand that paleomorphology before we could drill additional horizontal wells.

Following the first horizontal well, Rospo Mare’s development continued with Platform B and a first cluster of five horizontal wells, drilled in 1986 and 1987. A snap for the drillers who had combined horizontal drilling and extended reach wells. Production confirmed the advantages of horizontal wells. The wells’ 600-meter horizontal section, which explored the upper portion of the karst and intersected several vertical wells, increased the well’s productivity twenty-fold compared with a vertical well.”

Patrick Sorriaux Geological engineer

A 600-meter horizontal section increased production twenty-fold

Credit: Patrick Sorriaux

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ELF AQUITAINE LAUNCHES HORIZONTAL WELL COMPLETION R&D PROJECT

1. The Test Wells7.ELF AQUITAINE LAUNCHES HORIZONTAL WELL COMPLETION R&D PROJECT

1. The Test Wells

2. The State of Well Logging and Completion Equipment

Treating the Horizontal Borehole Before Production StartsSome of the cuttings are left behind in the horizontal section when a horizontal well is drilled. On the Lacq test wells, the R&D team observed that beyond a 60° angle, rock fragments were ground up very finely by the drill string and partially plugged the wall of the geological formation. As a result, prior to the start of production, it was necessary to unclog the well along the entire length of the productive zone. This is typically done by injecting a diluted acid through the well wall. In vertical drilling, the formations being treated are not very thick, so it is fairly simple to get the acid into contact with the entire boundary of the reservoir intersected. Because horizontal wells are so long, it is vital to spread the acid out as evenly as possible.A novel acid well treatment method was developed and applied for the first time in the Lacq 90 well.

> The acid was applied using a pipe lowered to the bottom of the well.

> The pipe was then moved to the edge of the zone where the acid was present.

> At the surface, the wellhead was closed at the annulus between the pipe and the well casing. First water and then gel were injected. The goal was to force the acid through the walls of the targeted portion of the well.

> Inside the well, the acid was replaced by a fluid viscous enough to remain in place during the trip.

In 1980, horizontal wells were drilled to improve the productivity of so-called complex reservoirs. One of the major

challenges was managing horizontal wells’ production along their entire length — hundreds of meters — and over several decades.

Independent Sections Extend Well LifeIt is important to prevent well walls from collapsing. The risk of a well becoming unstable increases as it gets longer, and horizontal positioning breaks the symmetrical distribution of mechanical stress in the rock. The productive zone, which is several hundred meters long, often cuts through a variety of geological facies owing to the reservoir’s heterogeneity, and through fractures that are sometimes the driller’s target. Variations in the petrophysical properties of the porous matrix play a significant role in flow.

These properties make it necessary to iso-late homogeneous sections of the well, which are produced independently of each other, with each section being equipped and operated in the most appropriate man-ner. The system must be flexible enough to deal with successive changes in the distri-bution of fluids within the reservoir over the life of the well.

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These actions were repeated as often as necessary to distribute the acid evenly along the entire horizontal section of the well. This method made it possible to increase a well’s production capacity 2.5 times under equivalent pumping conditions.

Isolating Sections for Selective ProductionDuring the drilling of the horizontal section of the Lacq 91 well, drilling fluid losses and well logs showed that there were fractures a few millimeters wide at a depth of around 1,050 meters. These fractures were responsible for the significant water content of the volumes produced during the well’s eight months of operation.After this initial phase, a workover operation was conducted to plug the fracture and an attempt was made at selective production of the horizontal well. The stages were as follows:

> The slotted liner installed at the end of drilling was raised and the borehole was cleaned.

> To verify that most of the water pro-duced came from the fracture that had been discovered, cold water was injec-ted, then temperature measurements were taken with the help of temperature sensing probes to pinpoint the location where the cold water was entering and cooling the surrounding rock.

> The installation and simultaneous hori-zontal movement of three temperature sensing probes, each along one-third

of the producing section of the well, represented an advancement in terms of diagnostics.

> The well bottom was protected by tem-porarily plugging it with gel, and the frac-ture was sealed by injecting 15 tons of cement slurry onto a support structure consisting of two tons of sand.

> After the borehole was cleaned, a second injection test proved that the fracture had effectively been sealed.

> The casing for the well was lowered, but packer expansion by injection of a ce-ment slurry did not allow the team to iso-late the sections as planned. After holes were perforated to allow passage of the cement slurry, the casing was cemented. The team then verified the quality of the cementing using hydraulic and acoustic methods.

Once the workover had been completed, the Lacq 91 horizontal well was divided into three sections separated by two packers. The first, called the upstream section, was lined with cemented casing. The second, called the intermediate section, covered the fractured and sealed zone. The third, called the downstream section, was equipped with a pre-slotted liner.The upstream segment was perforated later, using the SIMPHOR method.The other two sections were produced si-multaneously and independently using two pumps, each incorporated into its own pro-duction string.

2. The State of Well Logging and Completion Equipment

The early 1980s saw a revolution in well logging, completion and maintenance. Producers had questions about the

techniques used up until that point for vertical drilling:

> Would it be possible to adapt them to horizontal wells?

> What sort of completion would work best?

> What kinds of methods and procedures could be used for horizontal wells?

> Would it really be possible to perform the same operations on a horizontal well as on a conventional well?

Elf Aquitaine and the IFP enlisted the R&D team to find the answers. The “Horizontal Well Completion” and “Horizontal Well Production (PRODHOR)” projects high-lighted the “additional challenges posed by horizontal drilling” — gravity and well length — that would require the team to adapt conventional tools and design new ones specifically suited to horizontal wells. Below is an overview of those efforts.

Well LoggingWireline logging, which was commonly used in wells up to an angle of 65 to 70°, gave way to new technologies: > Logging while drilling (LWD), the first

method for obtaining real-time data on a reservoir, including gamma radiation, resistivity, temperature and density (density tool).

> SIMPHOR, developed by the IFP, and sim-ilar products sold under license, such as Tough Logging Conditions and the Drill Pipe Conveyed Logging System.

> Coiled tubing, a simple technique that is quick to set up, but is not the most effective for pushing tools over a long horizontal distance.

> The pumpdown stinger, a pump that drives logging tools through the drill-pipe. This blowgun-type method can only be used for small-gauge tools.

Completion Using a LinerMost horizontal wells are equipped with slotted liners. But other configurations are possible, including uncased wells, ce-mented casings and pre-slotted partially cemented casings with external packers. In ideal circumstances, the well would only pass through one reservoir and one type of fluid, and would be subject to a single, uniform pressure. In such a case, if the geomechanical strength is sufficient, the well can remain uncased and simply fitted with a pre-slotted liner.Other solutions are needed if the configura-tion is less than “ideal,” meaning there are significant heterogeneities, faults, multiple facies, gas caps, aquifer-fed networks or multiple reservoirs crossed. In these cases, it is necessary to isolate certain well sec-tions and guard against unexpected inflows of water or other fluids. The two techniques recommended for this are cementing and inflatable packers.

ELF AQUITAINE LAUNCHES HORIZONTAL WELL COMPLETION R&D PROJECTELF AQUITAINE LAUNCHES HORIZONTAL WELL COMPLETION R&D PROJECT

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Completion DesignCompletion efforts rely on data, such as the type of rock, which fluids are present and whether there are heterogeneities. But the best design will also be able to deal with fluid inflows. This is relatively easy in a vertical well, but much less so in a horizontal well. For example, it is particularly difficult to predict the oil/water points of contact, gas coning and such that can occur at any time and any point along the horizontal well. There are always unknowns, and it can be hard to decide on a completion method before observing the well. On Rospo Mare, the wells were not cased so that teams could install a suitable liner depending on the flows. On Lacq 91, the initial liner was replaced with a new one after a year to better protect the well against water inflows.

Well CementingCementing a well poses two problems that must be avoided: the formation of water in the upper portion and the presence of re-sidual mud. Lab tests have confirmed the following techniques: > Well Cleaning

Removing cuttings to the surface is much more complicated in the horizon-tal section than in the portion between the angles of 30 and 65°. Different methods are used for the two sections.

> CasingThe casing must be centered using a system of centralizers and stabilizers that leaves enough space around the an-

nulus so that drilling mud is not trapped. > Mud-Cement Spacing

There must be enough space to prevent mud from getting trapped.

> CementA cement slurry is used to prevent water migration.

> PumpingIf possible, the cement is pumped under turbulent flow conditions.

> Well LoggingTo verify the cementing results, it is necessary to center the logging tools or to use tools attached directly to the casing.

PerforationVarious techniques — including coiled tubing, pumpdown stinger and SIMPHOR — can be used to perforate the cement of a horizontal well casing. They supplement the tubing conveyed perforating method, which is well suited to horizontal drilling. The very high cost of perforation is a key factor in deciding which method to use. It also raises the question of whether it is necessary to cement the casing.

Sand ControlThis is vital in unconsolidated clastic, or sandy, reservoirs. The accumulation of sand in the casing, even in small quanti-ties, can cause problems in the operating phase. Several systems have been tested: > Chemical Consolidation

Used in vertical wells, this method is not effective for horizontal wells.

> Gravel PackingGravel acts as an effective filter when packed tightly enough.

> Sand Filters All of the tests show that this is an effective solution, and is the method of choice for horizontal wells.

Well StimulationAs with conventional wells, the choice of stimulation procedures for all or part of the horizontal section depends upon the well completion method (open hole, cased and cemented, uncemented, equipped with sand filters, production casing, etc.). > Acid Well Treatment

In an open hole horizontal well, acid well treatment can be done along the entire length of the well or section by section, by isolating the section being treated. For cemented and perforated casings, using a cup tool is recommended to pro-vide a path for the acidized fluid to pass through the casing. Uncemented, unper-forated casing is the most frequently used configuration, and also the most complex.

FracturingConventional well processes can also be used for horizontal wells. For the most part, this means hydraulic fracturing using propping agents for wells with a cemented casing. The fracturing equipment, packers, perforations, plugs, fluids and so forth are all easy to adapt.

Completion EquipmentSome horizontal wells are put into produc-tion using single completion for the length of the well. Others use dual completion. When the casing divides the well into multi-ple sections, selective production methods can be used.

Completion equipment

ELF AQUITAINE LAUNCHES HORIZONTAL WELL COMPLETION R&D PROJECTELF AQUITAINE LAUNCHES HORIZONTAL WELL COMPLETION R&D PROJECT

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HORIZONTAL DRILLING’S FIRST TEN YEARS HORIZONTAL DRILLING’S FIRST TEN YEARS

Oh, the zeal of the converted! Conditions were ripe, and Elf Aquitaine quickly earned a reputation

as the industry standard for horizontal drilling. Its experts were in demand around the world. It all happened so fast. In just ten years, Elf Aquitaine drilled no fewer than 27 kilometers of horizontal wells. The FORHOR horizontal drilling R&D program, which ended in 1983, could proudly proclaim “mission accomplished.” The four wells drilled by the project team — Lacq 90, Lacq 91, Rospo Mare 6 and Castéra-Lou 110 — confirmed that horizontal drilling was technically and economically feasible. The stage was set.Alongside the horizontal drilling project, Elf Aquitaine and Total took part in an international research project led by Mobil to test the feasibility of extended reach drilling (ERD). Wells drilled using this technology started off at an angle of more than 70° or 80° in order to reach distant targets and in some cases end with a horizontal section.The Italian affiliate, which had been poised to start production on the Rospo Mare field for several years, launched its first drilling campaign (Rospo Mare B) in 1986-1987. Zuidwal followed in the Netherlands in 1988. The horizontal well business took off with both operated and non-operated wells. In 1990, it went global, notably due to the development of the Austin Chalk formation in the United States. Elf Aquitaine formed partnerships with Shell for 18 wells in the Rabi field, Amoco* for seven wells in Valhall, Norsk Hydro for two wells in Troll, Agip, BP, Chevron, and the list goes on.

1. Elf Aquitaine Drills 50 Wells Between 1980 and 1992

*Amoco is now part of BP, and Norsk Hydro of Statoil.

The “Review of Horizontal Drilling, 1980-1992,” which Elf Aquitaine published in February 1993, gives a picture of the scale of the phenomenon:

> 50 wells drilled in ten years, 25 of them in the Rospo Mare field.

> Average horizontal section length: 600 meters.

> Vertical depths ranging from 600 to 4,000 meters.

> 1.5 times more expensive than a conventional vertical or directional well.

> Reserves-to-production ratios ranging from 1 to 9, with an average of 2.5 relative to a conventional vertical or directional well.

> Only five failures in ten years, attributable to target miscalculation or high-risk wells.

Worth it! > More reserves developed per well. > Lower surface installation costs, notably

for platforms. > Lower operating costs.

Rospo Mare field (Elf Aquitaine)production per well

Key Figures In Practice

> Principal applications: Water or gas coning, productivity enhancement, fractured reservoirs.

> Most widely used technique: The long radius method.

> Horizontal drilling tested and proved feasible in a broad range of formations: Unconsolidated sand, tight sandstone, chalk, dolomite, limestone and granite.

> Most commonly used completion: Uncemented slotted liner.

> Keys to success: A good description of the reservoir and quality 3D seismic.

> Need to reduce drilling costs. > Need to shorten the learning curve.

Economic Performance (1992)

Room for ImprovementCover of Elf Italiana’s in-house magazine

m3/day (thousands)

Rospo well no.

Vertical Slanting Horizontal

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2. Elf Aquitaine’s Horizontal Wells Worldwide (1980-1992)

FRANCE > Two wells in the Lacq field in south-

western France to become proficient in horizontal drilling techniques. - Lacq 90, drilled in 1980 in a compact

zone in the eastern part of the Lacq Superior field. This well produced 11,000 cubic meters of oil from 1980 to 1992.

- Lacq 91, drilled in 1981 in a compact zone in the western part of the Lacq Superior field. Midway through the horizontal section, the borehole ran into a heavily fractured area. Due to the high water content, the team attempted to isolate the section in 1983. Ultimately, the well was abandoned in 1986 because it was only producing water.

> Castéra-Lou 110 (CLU110)This was the final well drilled as part of the FORHOR R&D program, in 1983. The goal was to improve productivity in the Brèche de Garlin formation. The team succeeded. On start-up, the producing rate was four times greater than for a vertical well. CLU110 confirmed the characteristics of a horizontal well: better initial recovery rates, more rapid decline, and heightened sensitivity to heterogeneities.

> ChâteaurenardDrilled in 1986, the CR163 well was in-tended to prove that a horizontal well was feasible in unconsolidated sand. The results did not live up to expectations.

> LACQ 414 was drilled in 1988 to inject steam between two lines of producing wells.

ITALY > Rospo Mare, the Global Benchmark

This large offshore reservoir was the impetus for the company’s efforts to develop horizontal drilling techniques. Elf Aquitaine drilled 27 horizontal wells in Rospo Mare between 1982, the year of the first test well, and 1992. That amounted to half of all horizontal wells the company spudded during those years. With time, the drilling/completion learning curve improved: the cost of drilling horizontally fell to 1.2 times that of a vertical or deviated well, for an initial producing rate four times higher and a reserves-to-production ratio of 3.3.

UNITED STATES/New Mexico > The Chacon Dakota CAD11 well that Elf

Aquitaine drilled in 1987 was a failure. The team hit their drilling target, 610 meters in sandstone formations, but the cost was twice the initial budget and production was disappointing, at around 10 barrels per day. The well was abandoned. Not the best reservoir for horizontal drilling!

OPERATED FIELDS

NETHERLANDS > Zuidwal, the first gas reservoir devel-

oped using horizontal drilling, was located in an environmentally sensitive area. Starting in 1988, the field was produced using six directional wells and three horizontal wells (ZDWA6, ZDWA8 and ZDWA9). Drilling, completed in 1989, did not pose any major problems and the extra cost was limited to 30%. The Zuidwal wells used an innovative well profile called a “stair step” to produce two formations separated by a less permeable zone. The three wells successfully produced twice as much as a conventional well, but with significant loss of pressure in the production tubing. The ZDWA6 well, which the team was able to equip with “large” tubing 5.5 inches in diameter, was the top performer.

> K6 FieldDrilled in 1991 and 1992, the K6-C2, K6-D2, K6-DN2 and K6-DN3 wells benefited from quality 3D seismic approaching the reservoir. The seismic confirmed the depth and thickness of the target, thereby “lighting up” the landing area. A first. Production results were as expected or better, although they did not confirm horizontal drilling’s superiority over vertical drilling, since the vertical wells’ performances were significantly enhanced by acid well treatment.

> L7 FieldThe goal of the well, drilled in 1991, was to produce the gas reserves of

the Upper Slochteren reservoir, and notably a horizontal extension of Lower Slochteren at a depth of 4,000 meters. Production started on the upper portion, but the horizontal section was ultimately plugged due to low flow.

> Harlingen (HRL7)In 1992, a horizontal well was drilled in a chalk formation to supplement four vertical wells in production since 1988. HRL7’s three goals were to increase productivity, better protect against water intrusion and accelerate production. Mission accomplished — the well produced 250,000 cubic meters per day, five times more than a vertical well.

OMAN > Sahmah – (SAH10)

Production from this technically complex well, drilled in 1990, was close to zero. It had a deep, long horizontal section of 1,000 meters that was drilled in a multi-fractured, tight reservoir. In hindsight, it was not a good candidate.

ANGOLA > Bufalo (BUF106)

In 1990, this was the deepest well ever drilled by the company, with a 525-meter horizontal section at a depth of 3,370 meters. Unfortunately, the team did not hit the target at the expected depth. A decision was made to descend under the water level and transform the well into a water injector. In the end, the horizontal section was plugged.

HORIZONTAL DRILLING’S FIRST TEN YEARS HORIZONTAL DRILLING’S FIRST TEN YEARS

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LES DIX PREMIÈRES ANNÉES DU FORAGE HORIZONTAL

GABON > N’Tchengué M’Bega (TCNE2HG)

Drilled in 1990, this was the second supplemental development well for the M’Bega sand body in the N’Tchengué field. The drilling process was challeng-ing, involving three sidetracks. Two of these were due to technical factors (sticking and back-off) and one was due to a geological factor (sandstone basal depth exceeded). The sandstone cap was 22 meters below where it was expected. Only 100 meters of the well’s 400-meter horizontal section were “useful.”

> Coucal (Dico4H and Dico5H)The reservoir was a 42-meter-thick pool of light oil located in the Gamba and Dentale sandstones. Development consisted of two vertical wells and two horizontal wells, drilled in 1991-1992.

REPUBLIC OF THE CONGO > Émeraude (EMP-03)

This, the third EMP pilot well, was drilled in 1992 to supplement a verti-cal well and a directional well. It had an unusual configuration, with the end drilled upward and a downhole pump at the lowest point, making it an “inverted well.”Tchibouela (TBM 111Z)Also drilled in 1992, the first of seven planned horizontal wells started produc-tion in early 1993, at 1,100 cubic meters per day.

UNITED KINGDOM > CLAIR (206/7a-2 and 206/8-9z)

The wells were drilled in 1991-1992. The 206/7a-2 well was intended to prove that the reservoir could produce oil from the fractured Lewisian basement and the upper sandstone formation. The target was reached, but production volumes were not commercial.

NON-OPERATED FIELDS

9.1983-1995 – EXTERNAL VALIDATION

1. Elf Aquitaine and the IFP Create Horwell in 1984

2. The CS Resources Assistance Contract in Canada

3. Horizontal Drilling Goes Global

4. The SIMPHOR System Finds a Lasting Niche

5. International Excitement As the Industry Gets on Board

NORWAY > Troll: (31/2-16S and 31/5-4AS1, 1989-

1990)Operated by Norsk Hydro; Elf Aquitaine had a 2.353% working interest.

GABON > Rabi, 50 vertical wells, 17 horizontal

wells (1989-1992)Operated by Shell Gabon; Elf Aquitaine had a 47.50% working interest. In 1993, horizontal wells accounted for half of the field’s production.

> Echira (Ech-4, 1992)Operated by Shell Gabon; Elf Aquitaine had a 42.50% working interest.

ANGOLA > Cabinda (four wells,1992)

Operated by Chevron; Elf Aquitaine had a 10% working interest.

REPUBLIC OF THE CONGO > Zatchi 215H

Operated by Agip; Elf Aquitaine had a 35% working interest.

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1. Elf Aquitaine and the IFP Create Horwell in 1984

By 1983, the FORHOR horizontal drilling R&D program had met all of its goals:

> The technical feasibility of horizontal dril-ling had been demonstrated.

> The technology made it possible to de-velop reserves previously considered inaccessible.

> Reservoir productivity had been improved. > The extra cost — declining with each ad-

ditional well — was more than offset by increased production.

Elf Aquitaine’s pioneering work on horizontal drilling set the industry standard and its engineers were considered the experts. Amid this jubilation and buoyed by international interest, Elf Aquitaine and the IFP created a services company, Horwell, in which each had a 50% stake. The company’s remit included disseminating the technology, advising companies considering this type of project and carrying out studies. The new affiliate, led by Jean-François Giannesini, set up its corporate offices just outside Paris in Rueil-Malmaison. The technical teams, who had worked on the FORHOR R&D program, offered a range of services available à la carte. A number of international oil and gas companies sought out IFP/Elf Aquitaine’s expertise via Horwell for reservoir studies, target calculation, drilling, planning and site supervision.

“The affiliate sold well engineering, drilling programs and onsite

assistance. We designed and helped drill BP’s first horizontal well, Beckingham 36, in Sherwood Forest in England. Then we went to Denmark, to help Maersk Oil in the Dan field. After that came India, where we conducted the studies for national oil company ONGC’s first horizontal well. I remember the endless meetings in Bombay, face to face with around 50 Indian engineers bombarding us with questions.

From beginning to end, the experience was exciting and enriching, taking us around the world to meet all kinds of people and tackle all sorts of technical challenges. Although, we should mention that at the time, not

Philippe Coffin and André Jourdan

At management’s request, we joined Horwell in 1984.

everyone agreed that Horwell was a good idea. Some people thought that Elf Aquitaine was ‘giving away’ its know-how and that our managers were making poor choices.And it’s true that our ‘clients’ quickly spread their wings and in some cases overtook us. It was BP, not Elf Aquitaine, that set the record for horizontal drilling in the United Kingdom. It was Maersk Oil that set the world record for horizontal drilling in Qatar in 2012.

Less than ten years after it was founded, Horwell ran out of clients. Horizontal drilling had become the industry standard. The affiliate was bought by a drilling company and refocused on killing oil well fires in Kuwait.”

2. The CS Resources Assistance Contract in Canada

In 1987, a prescient Canadian geologist, Dennis Sharp, founded CS Resources. The new oil company’s mission was to

develop very thin reservoirs of heavy oil in the area around Calgary using horizontal drilling technology. It set about buying fields that were impossible to produce using vertical wells from the big oil companies for pennies on the dollar.

At the same time, the enterprising Sharp contacted the IFP and Elf Aquitaine, with whom he signed a three-year license to use their technology. “So that’s how I wound up in Canada,” explains Philippe Coffin, the Elf Aquitaine representative assigned to provide technical assistance. “Between 1988 and 1990, we drilled around 50 wells. The results were staggering. Production went from zero to 15,000 barrels a day, more than Elf Aquitaine’s U.S. affiliate!”

The more wells they drilled in the Pelican Lake field, the faster they got, shortening times from 30 days for the first well to 10 or 12 for the last ones. In three years, the fledgling company’s workforce ballooned from two to 70. In 1992, the technology was still advancing, and they drilled a horizontal well with a multilateral branch. Starting in 1989, Sharp — named one of Canada’s Master Entrepreneurs in 1997 — began preparing to launch an initial public offering for CS Resources. A few years later, the visionary businessman sold the company for the tidy sum of CAD 500 million and went looking for new challenges in the oil sands.

Drilling rig in Alberta, 1989

1983-1995 – EXTERNAL VALIDATION 1983-1995 – EXTERNAL VALIDATION

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Canadian drillers made horizontal drilling technology more robust. For the first time, the drilling team used motors equipped with a bent sub. Now there was no need to raise the drill string and change it to modify its direction. In just a few months, drilling times were cut by two-thirds. High-flow rate helical gear pumps were lowered horizontally to pump the production, a world first. Total used the same techniques in the 2000s in the Petrocedeño (previously Sincor) project in Venezuela’s Orinoco Heavy Oil Belt.

3. Horizontal Drilling Goes Global

Attending conferences and conven-tions, authoring papers and books, in the 1980s the engineers who car-

ried out the FORHOR horizontal drilling and PRODHOR horizontal well production R&D programs became global ambassadors. In the days before laptops and Power-Point, Alain Spreux and André Jourdan crisscrossed the globe with their “slides,” some of them colored by hand. It was a pioneering era. In Luanda, they were un-daunted when a power outage downed the projector they were using for a presentation to the Petroleum Ministry. A white sheet did the trick, allowing attendees to take turns viewing each of the transparencies on a table! And the conversation continued in English, Portuguese and French.

“I remember a tour we did through the U.S. and Canada, to Los Angeles,

Houston and Calgary, among other places. We had two goals: to promote the advantages of horizontal drilling for oil and gas companies and to ask questions and report any problems that people were running into in the field.

André Jourdan and I visited the affiliates to encourage them to drill horizontal wells. The early days were tough. People looked at us a bit like snake oil salesmen. On top of that, people within the company were much harder to convince than the outsiders, despite the success of Rospo Mare.”

Alain SpreuxCompletion engineer and head of the PRODHOR horizontal well pro-duction R&D project

Convincing our affiliates

Polycrystalline diamond compact (PDC) fixed cutter bit

Pelican Lake and Winter fields in Canada

BRITISH COLUMBIA

ALBERTA

SASKATCHEWANPELICAN LAKE

EDMONTON

CALGARY

REGINA

WINTER

BAFFIN BAY

HUDSON BAY


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> 1980-1981: The success of the Lacq 90 well is the subject of a feature in Petroleum Engineer International entitled “Elf Well Turns 90 Degree [sic] — and Stays There.” A second article, this time on Lacq 91, soon follows: “Elf Drills 1,000 Feet Horizontally.” The technique is starting to spark curiosity and interest.

> 1982: The results of the Rospo Mare 6 test well make the front cover of oil and gas industry publications. The big oil companies want to know more. Many get in touch with the project’s managers.

> 1983: Pétrole Informations publishes “Review of Horizontal Drilling Progress.”

> 1984: Petroleum Engineer In-ternational publishes “Hori-zontal Well Proves Productivity Advantages.”

> 1987: The Society of Petroleum Engineers (SPE) organizes the first international forum on horizontal wells. Elf Aquitaine presents its accomplishments.

> 1988: Oil & Gas Journal, Technology publishes “Elf Has Set Up Rules for Horizontal Drilling” and “Horizontal Drilling Has Negative and Positive Factors.”

> 1988-1989: The production results of the three Zuidwal horizontal wells are presented at an SPE conference. The audience is clearly interested.

> 1990-1991: The SPE asks André Jourdan to give a series of lectures in the Middle East, Northern Europe and the U.S. on “Horizontal Drilling: Is It Worth It?”

ON THE PAGE AND ON THE STAGE

> Cairo, November 1982 – EGPC Production Conference: “Hori-zontal Drilling”

> London, March 1983 – 8th SPWLA Conference: “Horizontal Log-ging by SIMPHOR”

> Kristiansand, November 1983 – Northern European Drilling Conference: “Experiences in Drilling of Horizontal Wells”

> Stavanger, May 1984 – Offshore Northern Seas Conference & Ex-hibition: “Reservoir Development Through Horizontal Drilling”

> Houston, May 1984 – Offshore Technology Conference: “Offshore and Onshore European Horizontal Wells”

> Calgary, June 1984 – 5th Annual Advances in Petroleum Recovery and Upgrading Technology Conference: “The Four Horizontal Wells Producing Oil in Western Europe”

> Houston, September 1984 – SPE 59th Annual Technical Conference and Exhibition: “The Reservoir Engineering Aspect of Horizontal Drilling”

> New Orleans, February-March 1989 – SPE/IADC Drilling Confe-rence: “How to Build and Hold a 90 Degree Angle Hole”

> Houston, July 1990 – SPE/ University of Houston Emerging Technologies Conference: “Well Deviation Optimization for Pro-duction Improvement”

> Sicily, October 1990 – The Euro-pean Oil and Gas Conference: “Horizontal Wells and Reservoir Management Strategy”

> Bandung, 1995 – International Symposium on Horizontal Well Technology: “Horizontal Wells, a Standard for Tomorrow”

ON THE STAGE, AROUND THE WORLD


Jacques Bosio was an active leader of the Society of Petroleum Engineers (SPE).

He did a great deal to disseminate Elf Aquitaine’s experience and shine a light on the advantages of horizontal wells. Starting in 1989, he visited local SPE sections around the world, eagerly recounting our horizontal drilling saga and promoting horizontal wells. In 1993, Mr. Bosio became the first non-U.S. president of the SPE.

Jacques Bosio, Deputy R&D Director for E&P, Takes to the Road

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4. The SIMPHOR System Finds a Lasting Niche

From 1988 onward, most oil field developments relied on horizontal drilling. Also from that date, the

SIMPHOR system became the equipment of choice for logging in horizontal wells. In 1985, the IFP sold five so-called standard SIMPHOR systems with a 127-millimeter (5-inch) diameter to Schlumberger, making it possible to transition from prototype to a commercial phase. SIMPHOR’s inventor, Christian Wittrisch, traveled around the world to explain the equipment and train well log operators. “We had to overcome inertia and change habits in what was still a traditional business.” Starting in 1986, licenses to use the SIMPHOR patent, involving royalty payments linked to revenues, were sold to well logging services companies operating around the world, including Schlumberger, Halliburton, Baker Atlas and Gearhart. From 1988, SIMPHOR equipment was built and sold under license on a commercial scale by Vinci Technologies, an IFP affiliate.

The equipment was tailored to customer needs and well properties. Several models in different diameters (5-inch, 3-and-3/8-inch and 2-and-7/8-inch) were offered. The most popular option, with at least 60 sold, was the so-called modular SIMPHOR, which combined the 5-inch and 3-and-3/8-inch gauges. Deutsch acquired the license for the male wet downhole electrical connector, initially made by IFP, in 1990. The licensees received technical assistance on how to use the equipment and training at the drilling site.In 2011, more than a hundred variants manufactured by well logging services companies were in use around the world, including systems made by Schlumberger, Baker-Atlas, Reeves-BPB, Geoinform (Hungary), Petrom (Romania), Geofizyka (Poland), and COOLC-CNLC (China). Vinci Technologies, initially an affiliate of IFP Énergies Nouvelles (formerly the IFP) and now independent, sells SIMPHOR equipment under license, entirely for export.

5. International Excitement As the Industry Gets on Board

In just ten years, horizontal drilling became the industry standard, but it was also a boon to universities, professional organizations,

and experts. The Americans were the first to offer courses, reference books appeared in every language, and a steady stream of lectures was given around the world. The technique was also eagerly embraced by the services companies that distributed and perfected the technology first tested by Elf Aquitaine. “During the development phase, we collaborated extensively with these companies — drilling, directional and completion specialists — who were willing to take risks, sometimes breaking equipment. They invested without knowing what the payoff, if any, would be. When the technology found its feet, it was natural for them to benefit from the momentum and take a lead over the companies that had been more hesitant. This ‘commercial sharing’ of the technology was what kept costs down and made it more accessible,” explained Alain Spreux, completion engineer and head of the PRODHOR R&D program in 1985.

Elf Aquitaine feature report prepared by André Jourdan, Philippe Coffin and André Sagot

An original SIMPHOR brochure


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10.TOTAL’S CONTRIBUTION

1. Drilling Record in Argentina:

10,585 Meters of Offset in 1999

TOTAL’S CONTRIBUTION

1. Drilling Record in Argentina: 10,585 Meters of Offset in 1999

BackgroundArgentina’s Hydra field is located around 12 kilometers off the coast of Tierra del Fuego in 35 meters of water. In 1989-1990, early developments by Total Austral, Total’s Argentine affiliate, used directional wells drilled from the Hydra Centro and Hydra Norte platforms to reach the reserves.

The First Extended Reach WellsFive years later, innovative technology changed the game. Total Austral attempted the first well using extended reach drilling (ERD), HNP 7, in one of Hydra’s satellite reservoirs. The idea was to install a horizontal well at a large distance from the offshore platform to reach satellite reservoirs. The technique allowed Total to set a record in Latin America: the first extended reach well reached its target, with a total length of 6,982 meters, and the horizontal section started at 5,089 meters. Following this success, the site team and managers were exuberant, and the production lived up to their hopes: a natural flow of more than 2,500 cubic meters per day of crude, with no water. Two other wells were subsequently drilled in 1995 and 1996 and the outcome was just as impressive.

Horizontal Wells Live Up to Their PromiseIn the early 1990s, around the world, extended reach wells became an alternative way to produce satellite fields without building new platforms. They are both technically and economically reliable. The solution of placing a horizontal section far removed from the well’s starting point found a very specific application in Tierra

del Fuego, making it possible to develop a series of extended reach wells from platforms on the coast to produce offshore reservoirs. In 1997, Total and its partners decided to launch a second, even more ambitious campaign to develop oil and gas production in the Ara and Kaus satellite fields. The multidisciplinary project team traveled from Buenos Aires to Rio Grande, where they shared offices with the administrative and logistics teams of the Río Cullen and Cañadón Alfa treatment plants. They planned to drill eight new wells from the coast. Five were completed within a year, and the team set a new record by drilling the AS-3 gas well, which had 7,973 meters of horizontal offset to the end of the well and a vertical depth of 1,615 meters. One well was drilled in only 90 days, with 700 meters of tubing conveyed perforating (TCP) completion in a single section in the horizontal portion, an exemplary performance! Drilling times were getting shorter. “Between the AS-2 and AS-5 wells, drilled nine months apart, the

Drilling of the first extended reach well, HNP 7, in Tierra del Fuego, Argentina

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drilling time fell from 96 days to 51,” noted Roland Vighetto, ERD Project Manager at Total Austral (1993-1996 and 1998-1999).

Record Offset in ArgentinaMarch 1999 brought with it a new challenge. Total Austral, with support from its partners Deminex and Pan American Energy, broke down barriers and achieved “the impossible” with the CN-1 well, drilled to a length of 11,184 meters from the onshore Cullen Norte site. It had a total horizontal displacement of 10,585 meters, at a depth of 1,650 meters, and navigated a reservoir that in places was only three meters thick. An offset more than six times greater than the well’s vertical depth was yet another groundbreaking technical performance and set a world record. To get an idea of what it would take to place a well within that reservoir, imagine trying to thread the spine of a passport with a thread as fine as a human hair and three storeys long.

TOTAL’S CONTRIBUTIONTOTAL’S CONTRIBUTION

The innovations deployed in this unprece-dented drilling project in a protected site included, among other things, a newly de-veloped laydown-pickup machine to rack the drillpipe and the use of more than 4,000 meters of small-diameter 4-inch drillpipe and tubulars fitted with high-torque, wedge-thread connections to ensure power trans-mission to the drill bit.

CN-1 well configuration

A NUMBER OF FACTORS EN-ABLED TOTAL TO PULL OFF THE ERD CHALLENGE

They included the company’s innova-tive spirit; the Total Austral team’s ex-perience, versatility and continuity; and the slim-hole well configuration. To top it off, due to favorable conditions, the team implemented this record-setting project for 20% less than the originally planned costs.

“We installed horizontal sections at the bottom of high-angle wells to

reach more distant reserves from a single platform. The first tests in the North Sea Alwyn field in 1988 and 1989 produced two record-setting wells in terms of offset and angle, N28 and N29. They were successfully drilled to a length of more than 7,000 meters without horizontal sections. The technology also proved itself in the early 1990s in the Paris Basin in the Montmirail field. This was at the same time as the first Rospo Mare developments. I knew the Elf Aquitaine engineers who were working on horizontal drilling. The whole oil and gas community was keeping a close eye on their results. It was a pioneering time. We were a small band of engineers on the lookout for innovations. We had faith in technology.

Then came Argentina. The first wells there were highly deflected and particularly productive. They were drilled from two offshore platforms.

The question quickly arose as to how we could economically tap the rest of the reserves, scattered about at a distance of more than 7 kilometers from the shore. Building more offshore platforms would have been too costly, so we decided to go back to ERD technology, this time from three onshore sites. The results were encouraging. Each horizontal well took us a little farther, until in 1999 we set the record: 11,184 meters for the Cullen Norte No. 1 well. In 2013, that well still boasted the world’s fifth-longest offset.

Three team members played funda-mental roles in the Tierra del Fuego project. Thierry Delahaye led en-gineering efforts from 1993 to 1996, when he took over for me. Herbert Lescanne was my very able se-cond during the offshore campaign for the first three wells (1994-1996). Matthieu Naegel was a part of the project from the start of work on the drilling rig in 1995, and by 1999 was working closely alongside me. With-out him, we might not have made it!”

We had faith in technology.

Roland VighettoERD Project manager, Total Austral (1993-1996 and 1998-1999)

ratio H/V 6.24 6.39 VD 1,666 m 1,656 m

MD 11,021 m 11,184 m

Horizontal Departure 10,422 m 10,585 m

9"5/8 csg at 6,350 m MD 7" liner at 10,025 m MD

5" cemented liner

13"3/8 csg at 1,135 m MD

20"csg

> Progressive Build Up Rate (BUR = 1.5 to 3.5°/30 m) > Long Slant Section (5,215 m, inc. 81°)> Long Sub Horizontal Reservoir Approach (88°)> Lateral Branch

6766

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11.OTHER APPLICATIONS

1991: Horizontal Drilling Rescues Salt Production in Southern France

1997: The Technology Advancement for Multilaterals (TAML) Joint Industry Project Is Created

2000-2007: Horizontal Drilling Makes the Congo River Submarine Canyon Crossing Possible

2006-2014: Horizontal Drilling Ushers in a New Era of Shale Oil and Gas Production in the United States

2015: Total Helps Develop SAGD Technology in Canada

OTHER APPLICATIONS

Elf Atochem bought the Vauvert site in France in 1983 to produce salt. At the time, Vauvert was the world’s

deepest salt mine. The layers of salt were 400 to 1,200 meters thick and were located beneath 1,900 meters of sedimentary rock. Reaching them meant drilling very deep. The drillers opted for a doublet system, drilling two wells 100 meters apart. Injecting water at 400 bar into one of the wells, called the barrel, fractured the saliferous layer. At that point, all that remained was to connect the two wells, so that the dissolved salt could be collected in the form of brine.

In 1991, everything changed. The drillers ran into a dead end, a fault that made it impossible to bridge between the LG3 and LG4 wells. Another solution was needed. They reached out to their oil and gas counterparts. The short-radius technique got production back on track. A horizontal test well with a short radius of around 18 meters was successfully drilled in the salt layer. Linking the two doublet wells with a horizontal passage increased salt production from 800,000 to 1 million tons while cutting costs.

1991: Horizontal Drilling Rescues Salt Production in Southern France

1997: The Technology Advancement for Multilaterals (TAML) Joint Industry Project Is Created

Multilateral well technology is nothing new. The first multilateral wells appeared in the late 1930s. Several

were drilled in the U.S.S.R. between 1950 and 1980 and in the U.S. starting in 1980. But it was the 1990s that saw the advent of the first so-called modern multilateral wells. The knowledge gained through drilling horizontal wells gave drillers the ability to make these systems more complex and increase the number of multilateral wellbores in order to reach satellite reserves.In 1997, a Shell Expro engineer created a group of operators, Technology Advancement for Multilaterals (TAML), to promote the technology’s spread in the

petroleum industry. It created the system for classifying multilaterals on a scale of 1 to 6 according to their technical complexity.Three times more multilateral wells were drilled in the early 2000s than in the previous 50 years. In recent years, oil companies have drilled around 75 multilateral wells worldwide each year. Total has gained valuable experience in level 1-2 wells and has drilled around ten level 3-4 wells.Multilateral wells offer several advantages over conventional wells:

> They have fewer boreholes, save time and cost less to complete.

> They reduce well density and surface footprint, which is a plus from an

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OTHER APPLICATIONS OTHER APPLICATIONS

environmental standpoint. > They improve reservoir drainage and

recover more oil and gas from thin or complex reservoirs.

> They improve productivity. > They reduce the risk of water or gas

intrusions.In 2012, it was estimated that there were more than 10,000 level 1-2 multilateral wells worldwide.

Multilateral well

2000-2007: Horizontal Drilling Makes the Congo River Canyon Crossing Possible

Background: In the early 2000s, the companies partnered in Block 14 in Cabinda, Angola — Total among

them — were looking for a reliable way to transport gas from Cabinda Province to an LNG plant in southern Angola. Cabinda Province is separated from the rest of Angola by a narrow strip of territory belonging to the Democratic Republic of the Congo and by the Congo River. The partners wondered if it made more sense to build an onshore or offshore pipeline. The second option won out because, not crossing a national border, it was considered more secure. That meant the pipeline would pass under the Congo River submarine canyon, presenting an unprecedented technical challenge, as the walls of the canyon are composed of

turbidite that causes frequent submarine avalanches. At that time, no pipeline or cable crossing the river had withstood these conditions for more than a few years.

In 2001, Total began a feasibility study. It looked at several scenarios — directional wells, horizontal wells, extended reach drilling and others — to cross the canyon, which is 400 to 2,000 meters deep and 4 kilometers wide. The project team drew on the company’s experience in horizontal drilling in Argentina and Venezuela, among other places; its crossing of the 1,350-meter-wide Mahakam River in Indonesia; and projects by other companies, notably the 1,359-meter Volga River crossing in 2000 and the 1,725-meter St. Johns River

crossing in Florida in 1995. It worked with a specialized contractor, HDI, which had set multiple records for river crossings.

Total Considers Two Solutions > The conventional solution would be to

drill a single well crossing from one side of the canyon to the other.

> A more innovative solution would be to drill two wells, A and B, one from each side of the river, and have them intersect at mid-point beneath the canyon. The horizontal section below the canyon would be an estimated 3,000 meters long, at a depth of 750 meters. Total ultimately recommended the second option. Horizontal drilling had become an industry standard and was perfectly suited to the project’s needs. The only question was how to make sure the two wells would intersect.

Chevron made it happen. Drilling was begun in 2015 by Chevron, the Block 14 operator, based on studies conducted by Total 14 years earlier.

Cross section of the Congo River crossing

A 3,000-meter horizontal well under a river

Bertrand BacaudWells R&D program manager,Total E&P

“The river crossing was a real technical challenge. The studies that Total

did in 2001 laid the groundwork for a robust, innovative solution. I had just joined the team and had previously worked on horizontal drilling in Tierra del Fuego. We came up with a truly novel solution: drill two wellbores, one from each side of the canyon, and join them underneath the canyon with a 3,000-meter horizontal section. Chevron ultimately took up the idea and made it happen. The intersection of the two wells using a 12-and-1/4-inch diameter section succeeded on the first try. The 11-and-7/8-inch casing was connected from one rig to the other with no major problems due to Vector Magnetics’ Active Ranging technology. Work was completed in 296 days at a cost of $240 million — a bit more than expected. Today, gas from Blocks 0 and 14 travels under the river to the LNG plant.”

South Well North Well

3,000 m0

0

750 m

A B

Credit: Chevron

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2006-2014: Horizontal Drilling Ushers in a New Era of Shale Oil and Gas Production in the United States

Horizontal drilling for shale oil and gas wells quickly became the technique of choice. In the mid-2000s, the tech-

nology proved perfectly suited to producing fluids with low natural mobility in large but thin formations. The conditions require creating the largest contact area possible between the layers containing the so-called unconventional hydrocarbons owing to their extremely poor petrophysical proper-ties, i.e. low permeability and porosity.

Stimulation and Horizontal Drilling Unlocking these resources required a successful combination of two relatively mature technologies: well stimulation through hydraulic fracturing, which aims to create a larger contact area with the matrix, and horizontal drilling, which makes it possible to have multiple-zone stimulation in a single well and thus achieve commercial production levels. Wells are grouped in clusters on pads, thus minimizing the surface footprint, optimizing the gathering network and making surface installations more efficient.

Cut Costs, Boost PerformanceAs with an offshore development plan, wells are drilled from a small-footprint starting point to reach resources located several kilometers away. With the advent of commercial-scale horizontal drilling and hydraulic fracturing, costs soon fell and upgraded rigs were installed. Tens of thousands of wells were drilled, with unit costs steadily declining as performance steadily improved. For example, an operator in the Texas portion of the Permian Basin that had 96% vertical wells in 2009 producing 200,000 barrels per day improved output to 650,000 barrels per day by 2014 with 42% horizontal wells.

In 2010, Total got into the game by teaming up with U.S. partner Chesapeake Energy, forming a joint venture to operate in Texas’ Barnett Shale.

> Good to know: In the United States, unlike most other countries, owners of property also own the mineral rights. Even if it is not visible from the surface, a horizontal well requires the prior consent of all of the landowners affected, and they can be numerous. Companies looking to drill in the U.S. must devote a large number of personnel to the business of negotiating owner by owner, called land management.

Drilling rig in Forth Worth, Texas

Well clusters

OTHER APPLICATIONS OTHER APPLICATIONS

Credit: Dixxit and IDE

0 m

1,000 m

2,000 m

3,000 m

Horizontal well

to

to

OTHER APPLICATIONS

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Steam assisted gravity drainage (SAGD) wells are another application derived from horizontal drilling. Canadian company Sceptre Resources developed the first prototype in 1987 to produce low-mobility, extremely viscous oil in reservoirs at a depth of several hundred meters. With the SAGD technology, a pair of horizontal wells is drilled one above the other. The top well injects steam produced from recycled water and the bottom well produces the oil. The concept is simple: the steam in the top well heats the oil, making it more liquid and easier to extract.

SAGD technology has been used since 2002 in Canada’s Surmont lease, in the Athabasca oil sands region 63 kilometers southeast of Fort McMurray, developed jointly by ConocoPhillips and Total.

In 2015, the companies launched Surmont Phase 2. This thermal recovery technique

should allow the project to quickly reach production of more than 150,000 barrels per day from a depth of 70 meters. Eventually, the partners plan to drill some 150 pairs of SAGD wells at the site.

2015: Total Helps Develop SAGD Technology in Canada

FAST FACTS

Total drills 200 to 250 wells annually: > 80% are horizontal or high-angle

wells (development wells). > 20% are vertical wells

(exploration wells).

At end-2013, 61% of wells drilled in the United States were horizontal, compared with 31% at end-2008: 1,146 horizontal wells were drilled in 2013 versus 1,111 the previous year.

12.WHAT COMES NEXT?

1. Extending Offset, the Continuing Challenge

2. Innovating to Go the Distance

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WHAT COMES NEXT?

As time went on, drillers were able to go farther and farther. The offset record set by Total Austral’s 11,184-meter

well in 2000 has been broken. Two wells of more than 12,000 meters were drilled, one in Qatar in 2009 and then one in Russia’s Sakhalin field in 2011.A database set up by BP, to which all of the world’s oil and gas companies contribute, makes it possible to conduct an annual review of extended reach wells and to map them according to depth and offset. Analysis confirms that Total has successfully built on the technological breakthrough represented by horizontal drilling and maintained its lead. Over the past 15 years, it has drilled a number of “near record” wells in several countries:

> Angola: Total proved the benefits of extended reach drilling (ERD) in a deep offshore setting.

> Argentina: Several wells, including one more than 10,000 meters long, drilled between 1996 and 1999.

> Netherlands: Total drilled the country’s largest-offset well, at 8,161 meters.

> Qatar: Total hit its target, a reservoir 1 to 1.5 meters thick, with a 3,500-meter-long horizontal well at a depth of 4,500 meters. Geosteering made it possible to navigate changes in the formation and the reservoir.

> Republic of the Congo: 11 wells in the Nkossa and Nsoko fields, including the West African record of 9,152 meters.

Increasing offset further would open up new opportunities. In the long run, extending wells beyond 12,000 meters would put marginal reservoirs far from platforms within reach, minimize environmental impact to give drillers access to fields in national parks and other protected areas, and make it possible to produce remaining reserves from certain mature fields at a lower cost.

1. Extending Offset, the Continuing Challenge

2. Innovating to Go the Distance

Total is involved in a number of R&D programs alongside services companies and start-ups specializing

in ERD. Their goal is to test and qualify the technologies that will let drillers tackle offsets of up to 20,000 meters in the near future. Adding another 8,000 meters to the most recent records would let them reach marginal reserves from existing platforms without building new ones.

Gaining 1,000 Meters with Aluminum DrillpipesTotal and a partner are studying the possibility of replacing steel drillpipes with aluminum ones. Aluminum is lighter and more buoyant, making drilling easier. On the other hand, it is less robust and cannot withstand temperatures above 100°C. As a result, its use would be limited to shallow wells. Tests are under way. This material

WHAT COMES NEXT?

could put a 13,000-meter offset within reach, which would beat the current record by 1,000 meters.

Reaching 20,000 Meters of Offset with Reelwell TechnologyReelwell, along with several other companies including Total, has undertaken an ambitious ERD research project. The Dual Drill String (DDS) developed by this Norwegian start-up, which represents a break from conventional drill strings, could be a major technological advancement. Clean drilling fluid flows down to the bit via the drill string annulus, while the return fluid with cuttings is pumped up to the surface through the inner string.

The annulus between the string and the well wall is filled with heavier mud. The “heavy over light” drilling technique reduces torque and resistance, which makes it possible to drill horizontal sections beyond the reach of conventional techniques. The pressure on the formation also remains constant throughout the drilling phase. The advantages of this technique are that the mud has less of an impact on the wellbore and there is less head loss in the formation, fewer fractures and excellent pipe buoyancy in variable density muds. The Reelwell technology could make it possible to reach offsets of 20,000 meters. Trials are currently being conducted.

> More powerful drilling rigs, with power swivels — sometimes referred to as top drive motors — replacing rotary tables.

> More robust drill strings that can handle torque and transmit it from the surface to the bottomhole.

> Increasingly efficient drill bits and drill strings.

> More precise control over trajecto-ries due to the rotary steerable sys-tem (RSS).

> New additives used in drilling fluids. > More precise well position mea-

surement tools. > Sensors to verify that bottomhole

pressure is the same as design assumptions.

> Advances in hydraulic engineering and removing drill cuttings.

> Simulation tools that provide a clearer picture of well cleaning and drill cutting management.

ADVANCEMENTS IN THE LAST 15 YEARS

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ET DEMAUN ?

13.BOLDNESS, MUTUAL SUPPORT,CROSS-FUNCTIONALITY AND LISTENINGA ConversationWith Daniel Plathey, Vice President R&D at Total Exploration & Production, and Benoît Ludot, Vice President, Drilling & Wells at Total Exploration & Production

BOLDNESS, MUTUAL SUPPORT, CROSS-FUNCTIONALITY AND LISTENING

A ConversationWith Daniel Plathey, Vice President, R&D at Total Exploration & Production, and Benoît Ludot, Vice President, Drilling & Wells at Total Exploration & Production.

How do you view the FORHOR horizontal drilling R&D program? How did it change the oil and gas industry?

Daniel Plathey: The 1980s completely revolutionized the oil and gas industry. Horizontal drilling made it possible to develop steam assisted gravity drainage (SAGD). Without this thermal enhanced oil recovery method, we could never have produced the Surmont lease in Canada. Horizontal drilling has also been used

extensively in the deep offshore, where we are now a global leader. But behind the technology are the people who made it happen. Horizontal drilling has been a tremendous human adventure, a remarkable dialogue between our Geosciences and Drilling teams, who joined forces to solve the puzzle of reservoirs that, because they were too thin or the oil was too viscous, could not be developed using conventional vertical wells. Mostly notably, the FORHOR R&D program made it possible to tap

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Rospo Mare, one of Europe’s biggest oil fields. The takeaway is that problems are easier solved by working together than by sitting alone at your desk.

Benoît Ludot: Horizontal drilling turned drilling upside down. It was a disruptive innovation for the oil and gas industry, a bit like with rotary drilling once upon a time. The transition was swift. The technology became the international standard in less than a decade. Horizontal drilling expanded the scope of what was possible and let companies produce resources previously considered economically and technically impracticable. Forty years later, it continues to open new doors, recently paving the way for the development of shale oil and gas production.

The pioneers of horizontal drilling had to work hard to convince management that the technology was viable. What about today?

Daniel Plathey: Nothing has changed! Selling a new idea is never easy. Especially if it’s a break with the past or seemingly unrelated to our core business. Some good examples are the robots used in carmaking, nanotechnology in medicine, or the big data that R&D teams are interested in for developments in oil and gas. New ways of doing things shake up people’s frame of reference, so researchers need to make their ideas appealing. People championing projects have to be tenacious and ready to fight their corner. And they need to be visionary, which the key players in horizontal drilling were.

How does a project like this reflect the company’s values?

Benoît Ludot: The FORHOR project is a perfect illustration of boldness, cross-functionality, mutual support and listening. People from three areas — Drilling, R&D and Geosciences — collaborated closely to prove the technology would work. The pioneers of horizontal drilling were the very embodiment of boldness. A handful of true believers fought for their project, got it funded, and ultimately won international recognition. Listening was another of the project’s strengths. Horizontal drilling wasn’t accomplished in a day. Those who brought it to life listened to what the people in the field were saying, to their competitors with their breakthroughs and to ideas from other countries. That’s another lesson of this epic story of modern technology: it’s important to remain open to the outside world, always on the lookout, so that the seeds of ideas can germinate and grow.

Daniel Plathey: The horizontal drilling project had boldness and tenacity in spades. The project’s participants remember an “impossible dream” that “managers didn’t believe in” and that had “many detractors.” It took mutual support among those trailblazers to carry the project to completion. And listening: the pioneers of horizontal drilling capitalized on advances in high-angle directional drilling, early work by Soviet and American drillers and more. The FORHOR R&D program added their pieces to the puzzle and transformed the dream into a success story.

What lessons do you draw from the program for your own field?

Benoît Ludot: Always listen to new ideas! Encourage our teams to be curious and forward thinking. Fight resistance to change. Horizontal drilling confirms the adage “nothing ventured, nothing gained.”

Daniel Plathey: Be receptive to unconven-tional ideas and disruptive technologies. They won’t all change the world, but some will. It’s important to identify those that will as soon as possible and not waste time pursuing avenues that are of no benefit to what we do. And once you get to a more advanced proof of concept stage, where costs start to mount, every effort has to be made to de-risk the technologies. Horizontal drilling was proved by its first Lacq test. An incredible stroke of luck! The technology was then confirmed in a real-world setting in the Rospo Mare field. The technology quickly reached maturity. On the other hand, not even the horizontal drilling project managed to avoid resistance to change — notably internal resistance. Would you say it was an exemplary effort?

Benoît Ludot: It was nothing short of a magnificent success for both Drilling & Completion and R&D. It sent a clear message to those who think that R&D is only for services companies and that operators must be content to shop around among off-the-shelf technologies. The FORHOR project showed that, quite the opposite, we have a strategic role to play using internal

resources — R&D and professional fields — in driving the technologies of tomorrow, putting the pieces together, and combining the best of what’s out there. In the case of horizontal drilling, services companies followed in our footsteps because the market was ripe for development. But it was our professional fields and R&D that came up with and proved the idea.

Daniel Plathey: The approach was exem-plary. It proved that there really are dis-ruptive technologies out there. You could measure the impact in additional barrels produced, sure, but it also enhanced the company’s image. Horizontal drilling did a lot to establish the company’s reputation for advanced technology. It’s a symbol of the role we have played in the petroleum industry.

Horizontal drilling has been a global standard for more than 30 years now. Why is it important to continue celebrating the story of this technological advancement?

Benoît Ludot: Technological innovation is hardwired in us. This story is fundamental to our spirit of innovation and creativity, and to the company’s culture. It’s the legacy we pass down to younger generations, who must chart their own course. In-house, celebrating milestone innovations is a source of pride. To the outside world, it makes a powerful statement about who we are. The French are often less vocal about their successes than their English-speaking counterparts. They shouldn’t be!

BOLDNESS, MUTUAL SUPPORT, CROSS-FUNCTIONALITY AND LISTENINGBOLDNESS, MUTUAL SUPPORT, CROSS-FUNCTIONALITY AND LISTENING

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Daniel Plathey: The technical side always tends to get second billing, as if it’s just an adjustment that the industry made. It’s good to put the technology center stage for once and remind people of the vital role that it plays. Telling the story of horizontal dril-ling gives us a chance to celebrate a major technological adventure, to publicize our technical leadership to both internal and ex-ternal readers, and to foster pride. It’s also a chance to tell the world who we are by looking back at the breakthroughs that have shaped us.

What is at stake apart from image and reputation?

Daniel Plathey: Technological advances such as horizontal drilling and deep offshore expertise clearly have a significant business component. Our standing as a technology leader is a competitive advantage. Today we are recognized for our ability to imple-ment technological breakthroughs and

incorporate new technologies in highly in-novative developments. As advances often do, horizontal drilling put us at the forefront of the oil and gas industry. This success story should spur us to remain bold so that we maintain our lead and continue to be seen as a pioneering company in France and beyond.

Benoît Ludot: The spread of horizontal dril-ling technology brings us back to a question that is still relevant today. Should we open-ly share our innovations or should we guard them closely? At the time, a decision was made to let other oil and gas companies in on the technology. That choice was in line with an open innovation strategy. Looking back at the experience is instructive, highlighting two conditions for long-term success: maintain technological leadership and always stay a step ahead. We invented the breakthrough, the industry followed our lead. But it’s our approach that has stood the test of time.

BIBLIOGRAPHIE

BIBLIOGRAPHY

BOLDNESS, MUTUAL SUPPORT, CROSS-FUNCTIONALITY AND LISTENING

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BIBLIOGRAPHY

> Jourdan, A. P. and Baron, G. A., “Elf Well Turns 90 Degree [sic] — and Stays There,” Petroleum Engineer International, January 1981, pp. 40-44.

> Jourdan, A. P. and Baron, G. A., “Elf Drills 1,000 + Ft Horizontally,” Petroleum Engineer International, September 1981.

> Jourdan, A. P., Reiss, L. H. and Wittrisch, C., “One, Two and Three Horizontal Wells in France and Italy,” Pétrole Information, 1567, April 15, 1982, pp. 17-23.

> “Horizontal Drilling – Three Field Tests,” Noroil, 1982.

> Jourdan, A. P., Reiss, L. H. Baron, G. A. et al., “Review of Horizontal Drilling Progress,” Pétrole Information, 1585, March 25, 1983, pp. 27-33.

> “Horizontal Drilling to Develop New Energy Resources,” Société Générale Energy Award, 1983.

> “IFP and Elf Aquitaine Solve Horizontal Well Logging Problem,” Petroleum Engineer International, November 15, 1983.

> Jourdan, A. P. and Baron, G. “Horizontal Well Proves Productivity Advantages” (October 1984), Petroleum Engineer International, October 1, 1984.

> Reiss, L. H. (Elf Aquitaine), Jourdan, A. P. (Elf Aquitaine), Giger, F. M. (IFP) and Armessen, P. A. (Top Services), “Offshore and Onshore European Horizontal Wells,” Offshore Technology Conference, May 7-9, 1984.

> Giger, F. M. (IFP) and Jourdan, A. P. (Elf Aquitaine), “The Four Horizontal Wells Producing Oil in Western Europe,” proceedings of the AOSTRA’s Fifth Annual Advances in Petroleum Recovery and Upgrading Technology Conference, Calgary, Alberta, Canada, June 14-15, 1984.

> “New Drilling Technology Enables Development of Italian Rospo Mare Field,” Noroil, 1986.

> Jourdan, A. P., Armessen, P. A. and Rousselet, P., “Elf Has Set Up Rules for Horizontal Drilling” and Armessen, P. A. “Horizontal Drilling Has Negative and Positive Factors,” Oil & Gas Journal, 86, No. 19, May 9, 1988, pp. 33-35, 38-40.

> Jourdan, A. P. (Elf Aquitaine) and Mariotti, C. (IFP), “How to Build and Hold a 90° Angle Hole,” SPE/IADC Drilling Conference, February 18-March 3, 1989, New Orleans, Louisiana.

> Jourdan, A. P., “Horizontal Wells, a Standard for Tomorrow,” International Symposium on Horizontal Well Technology, 1991.

> Coffin, P., “Le forage horizontal et les puits horizontaux” [Horizontal Drilling and Horizontal Wells], Presentation to Oil Company Management program students, HEC Montreal, 1991.

> Lien, S. C. (Norsk Hydro), Seines, K. (Norsk Hydro) and Havig, S.O. (Norsk Hydro), “The First Long-Term Horizontal Well Test in the Troll Thin Oil Zone,” Journal of Petroleum Technology, Vol. 43, 08, August 1991.

> Coffin, P., “Bilan des puits horizontaux, 1980-1992” [A Review of Horizontal Wells, 1980-1992], Elf Aquitaine, 1993.

> Drilling Sideways – A Review of Horizontal Well Technology and Its Domestic Application, Energy Information Administration, Office of Oil and Gas, U.S. Department of Energy, April 1993.

> “Des puits de science… À chaque type de réservoir son type de puits,” [Science Wells/To Each Type of Reservoir Its Own Type of Well], Produire No. 7, Elf Aquitaine Production, 1995.

> “Horizontal Highlights,” Middle East Well Evaluation Review, No. 16, pp. 8-25, January 1, 1996.

> Naegel, M., Pradié, E., Beffa, K., Ricaud, J., Delahaye, T. “Extended Reach Drilling at the Uttermost Part of the Earth,” SPE Annual Technical Conference and Exhibition, New Orleans, Louisiana, September 27-30, 1998.

> Vighetto, R., Naegel, M. and Pradié, E., “Total Drills Extended-Reach Record in Tierra del Fuego,” Oil & Gas Journal, May 5, 1999.

> Vighetto, R., Naegel, M. and Pradié, E., “Extended-Reach Drilling. Conclusion. Teamwork, Downhole Technology Expedites Tierra del Fuego Operations,” Oil & Gas Journal, June 7, 1999.

> “The Story of an Innovative Technique That Became a Commercial Success: System for Instrumentation and Measurement in Horizontal Wells” (SIMPHOR)], IFP Énergies nouvelles, 2011.

> Mau, M. and Edmundson, H., Groundbreakers: The Story of Oilfield Technology and the People Who Made It Happen, Upfront Publishing, 2015.

> Résseguier, P., Multilaterals 2012: State of Art, Total.

> McGinn, S., “Horizontal Wells: A Standard for Today,” World Oil, December 2014.

> Moureau, M., Brace, G. and Sevadjian, G., Dictionary of Drilling and Boreholes. English-French, French-English, Éditions Technip, 2011.

BIBLIOGRAPHY

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> Geosteering: Controlling the direction of a borehole based on the results of downhole geological logging measurements.

> IFP: French public research, innovation and training center renamed IFP Énergies Nouvelles (IFPEN) in 2010.

> Liner: A partial string of casing that does not run back to the surface.

> Liquefied natural gas (LNG): Natural gas that has been compressed and cooled for shipping.

> Logging while drilling (LWD): Technique that measures the physical properties of the formation in real time.

> Long-to medium-radius well: Well that requires several hundred meters to change from the vertical to the horizontal.

> Magnetic single shot: Miniature camera equipped with a compass.

> Measurement while drilling (MWD): Technique used to measure downhole physical properties (wellbore and geology). The MWD tool, located as close as possible to the drill bit, transmits the data to the surface via the drilling mud.

> Offset: Horizontal distance between the surface location and the bottomhole coordinates.

> Packer: Device that forms a seal for the production string.

> Paleokarst: Fossil karst whose cavities have been filled with sediments.

> Positive displacement motor (PDM): Downhole motor used to rotate the bit.

> Power swivel: A rig floor tool that can rotate a drilling string. Sometimes referred to as a top drive motor.

> PRODHOR: Horizontal well production R&D program begun by Elf Aquitaine in 1987.

> Pumpdown stinger: Pump that drives logging tools through the drillpipe. This blowgun-type method can only be used for small-gauge tools.

> Rotary drilling: Technique in which a drill string with a bit is spun from the surface (as opposed to percussion, or cable, drilling).

> Rotary steerable system (RSS): In rotary drilling, system in which the path of the bit is directed by a steerable component.

> Short-radius well: Well that changes from the vertical to the horizontal over just a few dozen meters and require special equipment.

> Side track: A lateral well drilled from an existing well.

> Side-entry carriage: Device used to guide the cable from inside the drillpipe to the exterior in the vertical or low-angle section of the borehole.

> SIMPHOR: French trade name for an instrumentation and measurement system in horizontal wells.

> SPE: Society of Petroleum Engineers.

> SPWLA: Society of Petrophysicists and Well Log Analysts.

> Steam assisted gravity drainage (SAGD): Thermal recovery method that uses steam to reduce the viscosity of heavy oil so that it can be produced.

> Steering tool systems: Bottomhole tools for transmitting directional data by cable (see AZINTAC).

> Technology advancement for multilaterals (TAML): Joint industry project to promote multilateral well technology. Multilateral systems allow multiple wells to be drilled and completed from a single wellbore.

> TELECO: First MWD system marketed. It consisted of a directional sensor made up of accelerometers and magnetometers, an encoder, a transmitter and a generator housed in a nonmagnetic drill collar. It was an integral part of the downhole assembly.

> Télépilote: French trade name for a variable angle bent sub.

> Temperature sensing probe: Tool for measuring temperature.

> Trihedral: Having three plane faces.

> Tubing conveyed perforating (TCP): Using a string of tubing to lower perforating guns into the well.

> Whipstock: A steel casing with a cutting tool that deflects the bit from the original borehole at a slight angle.

TECHNICAL GLOSSARYTECHNICAL GLOSSARY

The Story of an Industrial Revolution · Impossible Dream I n 1979, Elf Aquitaine* and the Institut...

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