New solutions and opportunities for the drilling industry due to fit-for-purpose composite casing

downhole

composite

pipes

Why discussing composites?

• Well construction cost reduction is priority today

• Currently relative small improvements are being made resulting in small cost savings

• New ideas and technologies are required to make significant improvements

• Composites offer unique properties enabling new solutions: o To reduce cost

o To (re-)move technical limits

downhole

composite

pipes

Composite properties

• High strength per weight ratio

• Low density (near buoyant in mud)

• H2S, CO2, corrosion resistant

• Electric isolator

• Non-magnetic

• Thermal isolator

• Low thermal expansion

SGSteel ~ 7.8 SGAlum = 2.7

SGComp ~ 2.0

downhole

composite

pipes

Composites

• Composites consist out of fibers and resin: • fibers for strength, i.e. glass, carbon, aramid, etc.

• resin matrix binds them together, i.e. epoxy, nylon, etc.

• Composite is an anisotropic material: strong in fiber direction

• Composites to be engineered to the application by placing fibers in the optimum direction

downhole

composite

pipes

Known applications

downhole

composite

pipes

Drilling applications

Composites not new in drilling industry: • High Pressure Riser

• Coil tubing

• Tubing

• Casing

Benefiting from corrosion resistance and low density Capabilities, capabilities and usage of composite pipes are growing Deep well applications require high axial and collapse pressure specifications

downhole

composite

pipes

Manufacturing

Filament winding:

Rotational Casting: • Fibers inserted dry in optimal

directions

• Resin injected using centrifugal force

• Curing under centrifugal force load

• Temperature controlled curing in completely closed environment

downhole

composite

pipes

Rotational Casting Technology

Rotational Casting to increase composite capabilities specifically for deep well applications:

o Better control on manufacturing process for better quality and higher specifications

o Produces pipes with industry standard constant outer diameter for easy handling and maximum drift

o Constant inner diameter according load requirements for maximum drift diameter

o Fibers can be placed in length and radial directions resulting for maximum drift diameter

o No void spaces for higher specifications

o Simple lining possible for extra wear resistance

downhole

composite

pipes

Connection Technology

• Connection need to handle high axial and combined loads in casing applications

• Extensive testing and modelling done to come to slender solution

• Steel-to-Composite cross-overs

downhole

composite

pipes

Composite Casing Design

• Finite Element Model to calculate lay-up design to match load requirements

• Variables include: o Fibre type, volume and

orientation

o Resin type and volume (Wall thickness)

o Curing characteristics

• Generic and project specific testing to confirm model results

downhole

composite

pipes

Opportunity – corrosion resistance

Composite casing is placed over loss-zone containing corrosive water: no cementation possible

downhole

composite

pipes

Opportunity – low weight

• Drilling or P&A’s from platforms with limited deck load

• Remote helicopter supported locations

downhole

composite

pipes

Solution – corrosion resistance

Steel forbidden to use in coal seam layers due to sparking:

• Slotted composite liner to stabilize coal

• Intersection easy to mill/drill, strong signal beacon / magnet

• Cased hole sidetracking possible for multilaterals

composite casing through coal seam

coal

downhole

composite

pipes

Opportunity – Low Density

• Longer reach wells

• Maximum reach: friction force equals driving force vertical section mass x g = friction factor x horizontal section mass x g

driving force generated in the vertical section

friction force generated in high

angle part of the well

downhole

composite

pipes

Opportunity - Low Density

• Buoyance of 7” casing:

o in air: 7.4 ppf vs 22.8 ppf (steel) : ~ x3

o in 10 ppg mud: 2.8 ppf vs 19.5 ppf (steel) : ~ x7

• HSCC results in:

o Low weight in horizontal section for low friction

o Steel running string gives relative high driving force

• Installed without rotation: no load on connections

• Circulation possible to ease installation and additional running options:

o Apply pressure to ‘stiffen’ pipe

o Pump down casing

downhole

composite

pipes

Opportunity – Transparency

• More efficient casing drilling

• BHA with standard MWD/LWD placed in ‘transparent’ composite casing section: o Less stick-out

o Stiffer drilling assembly for better drilling efficiency

o Shorter and lighter BHA

downhole

composite

pipes

Vertical weigth comparison Load for 3280ft well with 9-5/8” casing:

Conventional rig Super single rig

Material Specific Weight Buoyancy in mud

Hook load (klbs)

Steel casing 47.0 ppf 0.85 132

5” drill pipe 19.5 ppf 0.85 55

HSCC / ECCI 13.4 ppf 0.45 20

Mini rig

downhole

composite

pipes

Opportunity – Low Density

Combining low casing friction, good hole cleaning and absence of casing running enables drilling of deviated wells without rotation

Drilling without top drive e.g. crane based

downhole

composite

pipes

Opportunity – Transparency

Observation wells with open hole logging tools in protected environment:

o Induction resistivity

o Cross-well resistivity

o Magnetic Resonance

o Spectroscopy

o Sigma

o Density

o Surveying

o Sonar

Logging thru casing @5000m TVD

• Composite Casing installed at 16,450 ft TVD

• 7” Casing in 8-3/8” hole

• Observation well to monitor gas injection front with Magnetic Resonance equipment

downhole

composite

pipes

Project specific testing

• There is no certification for deep-well composite

casings because they did not exist

• Trial and testing program agreed with customer

• Tested under supervision of independant agency

TNO and collaboration of Delft University of

Technology

downhole

composite

pipes

Conclusion

• Composite technology being used in drilling industry for long time

• Recent developments increase capabilities

• Much of Akiet’s success comes from listening to and learning from you, our customer, and developing custom made products as a result

• Fit-for-purpose products create new opportunities to reduce costs or move technical limits

downhole

composite

pipes

Substantiation of claims

• Example test results of earlier order for pipe and connection 7”

Target load (incl Safety Factors)

Test result

Tension 89 klbs 280 klbs

Compression 32 klbs 100 klbs

Burst 3945 psi 3988 psi Collapse 2639 psi 3002 psi

Torsion 2212 ft.lbs 12022 1)ft.lbs 1) No failure at limit of testing gear

Akiet BV www.akiet.com info@akiet.com +31 6 83 79 51 87

downhole

composite

pipes

downhole

composite

pipes

Installation of 7” HSCC on Rig in Oman