Water Flood Design Surveillance Compatibility Mode

CHAPTER VI

Waterflood DesignWaterflood DesignSurveillance, and Evaluation

Ibrahim KocabasUAEU, Al Ain

Design involves both technical and economical considerations.

As a whole including reservoir, design and economic aspects any design should contain the following relevant information.

Waterflood Design Design Elements are: (Reservoir description) Reservoir evaluation and

d l f l i d ldevelopment of a conceptual reservoir model Selection of potential flooding plans Estimation of injection/production rates Estimation of injection/production rates Forecast of recovery over the project life Preliminary facilities designy g Estimation of capital expenditures and future

operating expenses Conduct decision analysis and economic

evaluationsId tif i bl th t t i it Identify variables that may cause uncertainity

Waterflood Design

The above design elements should be executed in the following phases of design and operation:following phases of design and operation:

I. Broad conceptual designII. Evaluation of the reservoirIII. Developing preferred alternativesIV O ti it i d l ti thIV. Operating, monitoring and evaluating the

waterflood

These phases will be detailed in the following

I. Broad conceptual design

This part contains two substeps :

1. Identify business opportunities: The waterflood objective is to enhance and/or accelerate the recovery and maximize profit Then the motivations could be:recovery and maximize profit. Then the motivations could be: Declining reserves Replacing or increasing reserves Performance under primary depletion Successful waterflood in the same or similar reservoirs

2. Perform a quick feasibility study on the attractiveness of the project.

II. Evaluation of the reservoir

Reservoir Evaluation consists of three steps:1 C ll i d l i h i f i1. Collecting and evaluating the information

for reservoir study and asset development l iplanning

2. Reviewing collected information for d bladequacy to enable us construct

development alternatives for a detailed dstudy.

3. Describing the further testing needs

II. Evaluation of the reservoir (step 1) 1. Collecting data for reservoir evaluation:

Data on Field information; Physical description of the reservoiry p f Areal and vertical extent of producing

formation, A and hf , Isopach maps of gross and net sand Correlation of layers and other zonesf y Surrounding environment, any information

on adjacent layers and aquifersj y q f

II. Evaluation of the reservoir (step 1)Collecting data for reservoir evaluation (cont ):Collecting data for reservoir evaluation (cont.): Geologic data

Physical boundaries ( Reservoir boundariesPhysical boundaries ( Reservoir boundaries, internal boundaries such as faults or other impermeable boundaries)p )

3. Reservoir characteristics (engineering data) Areal permeability and porosity variation and

h ( l dhence (Pay quality and continuity; zonationand natural fracture heterogeneities; Fracture orientation)orientation)

Vertical variation of permeability with thickness and zone

II. Evaluation of the reservoir (step 1)

Collecting data for reservoir evaluation (cont.):

4. Unusual completions5. Primary production history Primary producing mechanism Primary recovery data and remaining reserves Pressure distribution in the reservoir Existence of gas caps and aquifers6. Production equipment installed7. Well completion data

II. Evaluation of the reservoir (step 1)( p )Collecting data for reservoir evaluation

(cont.):(cont.):

Distribution of Resources Trapped gas saturation from solution gas

drive Vertical variation of saturation as a result of

gravity segregationg y g g Presence of mobile connate water Areas already waterflooded by natural drivey f y

II. Evaluation of the reservoir (step 1)Collecting data for reservoir evaluation

(cont.):R k fl id d k/fl id ti Rock, fluid and rock/fluid properties (engineering data)R l ti bilit f th i k Relative permeability for the reservoir rock

Gravity, FVF and viscosity as function of ireservoir pressure

Capillary pressure data

The reservoir evaluation should lead to development of a conceptual model of the reservoir !!of a conceptual model of the reservoir !!

II. Evaluation of the reservoir (step 2)2. Review data and based on the established

conceptual model decide (or Estimate);(This part is the major decision making part

of reservoir engineering aspects of waterflooding.) Possible flood patterns Injection and production rates Timing of the project and anticipated recovery over project life Identify variables that may cause

uncertainty in the technical analysis

II. Evaluation of the reservoir (step 3)

3. Describe further testing needs;( If t h h fid i t( If we can not have enough confidence in step

2, the we should specify the need for ) A il t fi ld t t A pilot field test Interwell tracer study Determination of residual oil distribution Determination of residual oil distribution Injectivity testsIn this part pilot field tests and tracer studyIn this part pilot field tests, and tracer study deserves special attention and pilot tests will be treated in detail in the following and tracertreated in detail in the following and tracer tests will be dealt in surveillance part.

II. Evaluation of the reservoir (step 3) : ( p )Pilot project design considerations

In pilot or full scale project success lies inIn pilot or full scale project success lies in acquiring the data needed to provide a meaningful interpretation of the processmeaningful interpretation of the process performance. For a pilot the purpose is to provide data under representative fieldprovide data under representative field conditions. We should keep in mind that our understanding of the process and henceunderstanding of the process and hence successful expansion of the project to filed scale depends on our ability to predict thescale depends on our ability to predict the performance of the pilot.

A pilot test is: An experiment conducted in the field An experiment conducted in the field A simulation of the larger field effort A place to make our mistakes before they get too costlyp ace o a e ou s a es be o e ey ge oo cos y A place to work the bugs of the equipment A place to develop the controls and data needed to

insure the success of the project A place to put our best engineering talent to the test and

t t i thto train others A place for intensive planning A place for open minds and compromiseA place for open minds and compromise A place for finding every problem imaginable with

their attendant delays

(step 3) : Pilot project design considerations

A pilot test is not:

A short term money making propositionA t t l fi ld i l ti A total field simulation

A great place to demonstrate theory in tiaction

III. Develop preferred alternatives

Detailed description of the technical and economic f h fl d d i h ld iaspects of the waterflood design should contain

information on the attractiveness of each item in the following:in the following:

a. Reservoir Engineering Partg g

Is reservoir description results adequate and p qpromising for implementing the waterflood?

III. Develop preferred alternativesp p

Attractiveness of Possible flood patternso Peripheral floodo Aquifer injectiono Central flood

P tt fl dio Pattern flooding Pattern configuration Well spacing Well spacing


Estimation of injection and production rateso Information from injectivity testso Empirical correlationso Local experience

Anticipated recovery over the project life o Material balance methodso Empirical correlationso Analytical modelso Reservoir simulators


Identify variables that may cause ncertaint in the technical anal sisuncertainty in the technical analysis

Original oil in place Sweep efficiency Sweep efficiency Injection rates Reservoir discontinuities Reservoir discontinuitiesBased on the results of each item of the alternatives one is selected andalternatives, one is selected and implemented. The next step is monitoring and evaluation of the design in practiceand evaluation of the design in practice.

V. Operate, monitor and evaluate waterflood

Monitoring and evaluation includes : Monitoring reservoir, wells and facilities performance Modify living reservoir model as additional data are

obtained from operational and evaluation of resultsobtained from operational and evaluation of results Evaluate performance and revise the earlier plan and

strategies based upon actual performance Id tif t iti f i Identify new opportunities for expansion

Plan a strategy for terminating the operation

Following are details of some important items in waterflood surveillance and monitoring.surveillance and monitoring.

VI.2 Waterflood Surveillance and monitoring

An essential key to a successful waterfloodingAn essential key to a successful waterfloodingproject is a well-planned and well-executed program of surveillance and monitoring Thisprogram of surveillance and monitoring. This program should be designed for each field differently due to differing characteristics ofdifferently due to differing characteristics of fields.

The basic elements of all surveillance programs are as follows:programs are as follows:


1. First element is that in general three major categories of field conditions should becategories of field conditions should be included in any waterflood surveillance program: reservoir conditions,program: reservoir conditions, injection/production well conditions and facilities/operating conditions.facilities/operating conditions.

2. The other element is record keeping/performance control.keeping/performance control.

3. The final element consists of considerations regarding economic conditions.regarding economic conditions.


Th ill d it iThe surveillance and monitoring program may be divided into two general type of activities

l t d t ti ti itinamely, measurement and testing activities.

Then the meas red q antities are emplo ed inThen the measured quantities are employed in a number of surveillance techniques forinterpretation and e al ation and remediationinterpretation and evaluation and remediation purposes.


The First part of measurement and testingThe First part of measurement and testing activities is observation of the items that needs to be regularly monitoredto be regularly monitored.

The second part consist of carrying out specialThe second part consist of carrying out special tests for diagnosis of problems commonly associated with waterfloods in other wordsassociated with waterfloods, in other words application of a well planned and well executed well testing programexecuted well testing program.

VI.2 Waterflood Surveillance (Part 1: Measurement

nd t tin )and testing)

Table 1 lists the items that should normally be included in the three major categories of surveillancethree major categories of surveillance.

Table 1. Listing of waterflood project items needing surveillance

Reservoir Wells Facilities/Operations

Pressure Perforations Water quality

Rates Fluid entry/exit Injection facilities

Volumes Cement integrity Production facilities

Cuts Downhole equipment Pipelines

Fluid samples Surface equipment Monitoring equipment

VI.2.1 Reservoir Surveillance (Part 1: Measurement and

testing)

The following items require constant monitoring in g q greservoir surveillance

R i ( kl di fReservoir pressure, ( weekly recording of bottomhole pressure readouts in submersibly pumped wells ) ( daily recording of pressures from surfacewells.) ( daily recording of pressures from surface headers, injection wellheads, producing well flow lines and fresh source-water injection headers)j )Injection and production rates, ( daily recording of them)

VI.2.1 Reservoir Surveillance (Part 1: Measurement

and testing)

Fluid volumes, (daily recording of oil water and gas volumes includes data from producing wells, water supply wells, fresh water injection into producers fro salt control, injection wells, and saltwater dispsal wells)WOR/GORs ( daily recording of them)

VI.2.1 Reservoir Surveillance (Part 1: Measurement

and testing)

Fluid samples ( weekly recording of producing well i h d H2S l l i h h fwater weights and H2S levels in ther gas phase of

producing wells. Quarterly analysis of injection water for oxygen content and oil carryover Annualfor oxygen content and oil carryover. Annual chemical analysis of all injected and produced water. However, special problems attributed to H2S , p pcorrosion, oxygen corrosion, inorganic scales and organic debris such as bacteria, paraffin and oil in water reverse emulsions can necessitate more frequent analysis of the produced or injected water.)

VI.2.2 Well surveillance (Part 1: Measurement and

testing)

For well surveillance ; there are four types of wells requiring surveillance: production, injection, water supply and water disposal.

Of these production and injection wells require the most attention.


testing)

Monitoring well performance requires aMonitoring well performance requires a program of selected well tests to be conducted regularly Types of well tests selected willregularly. Types of well tests selected will depend on surface/downhole equipment, well completion characteristics produced andcompletion characteristics, produced and injected fluids the stage of the waterfloodproject (early middle or late) and the reservoirproject (early, middle or late) and the reservoir description.


testing)

Key items for well surveillance are fluid entry into or exit from target zones, cement/completion integrity, and mechanical equipment, both downhole and

surface.

VI.2.3 Facilities and operations surveillance (Part 1:

Measurement and testing)

In general the ingredients common to most operations needing surveillance regarding facilities and operations are

injection/production facilities, fluid transmission lines, field monitoring equipment and, most important, water quality.

VI.2.3 Facilities and operations surveillance (Part 1: Measurement and testing)

Poor injection water quality is probably one of thePoor injection water quality is probably one of the most damaging conditions that arise in waterflooding operations. ( tests to perform onwaterflooding operations. ( tests to perform on water quality are

(1)geochemical analyses of the waters involved and the description of suspended solids,

(2)membrane filter tests to describe plugging effects f th d d lid dof the suspended solids and

(3) flow tests to study the effects of the injected water on formation core permeability )on formation core permeability )

VI.3 Waterflood Surveillance (Part II. Special testing)testing)

a. Well testing ProgramA i k h f l li i dAn important key to the successful application and

surveillance of waterflood is a detailed, accurate d fi i i f fl id fl h Fl id fldefinition of fluid flow paths. Fluid flow distribution is governed by reservoir properties,

ll di i d i i A llwell conditions and operating practices. A well planned and well executed well testing program

id fi i / ll di ican provide or confirm reservoir/well condition information that cannot be adequately obtained b hby other means.

(Part II. Special testing)W ll i Pa. Well testing Program

I fl di i i d / llIn waterflooding certain reservoir and /or well conditions can results in anomalous distribution of injection water which in turn may result in inefficientinjection water which in turn may result in inefficient flood operations. If fluid flow distributions can be ascertained then corrective measures can be undertaken as needed. The corrective measures can include injection and/or production well rate adjustment, well shut in, intermittent well operations, well conversions, injection profile modification and flood pattern revisionflood pattern revision.

(Part II. Special testing)W ll i Pa. Well testing Program

Unequal directional flow in the reservoirUnequal directional flow in the reservoir during waterflooding thus can be caused by both reservoir characteristics and well andboth reservoir characteristics and well and operating conditions.

Reservoir characteristics include variations in directional permeability faults permeabilitydirectional permeability, faults, permeability pinchouts, lenses, fractures and active aquifers.aquifers.

(Part II. Special testing) a. Well testing Program

Well and operating conditions leading to unequal directional flow are poor wellunequal directional flow are poor well conditions, unbalanced injection production rates, poor quality injection water.rates, poor quality injection water.

Regardless of the cause, unequal directional flow in a given reservoir must beflow in a given reservoir must be recognized, quantified and corrected.

For identifying the above problems, theFor identifying the above problems, the pressure transient testing and profile surveys should be carried out semiannually.should be carried out semiannually.

6.3.2. Project surveillance techniques based n th nit in p don the monitoring procedures are

Productivity index and inflow performance plots coupled with well-test plots of water cut and oil rates

Productivity index plots (barrels per day per psia drawdown vs time ) and inflow performance plots ( well operating pressure vs total reservoir withdrawal rate) depend on the proper measurement of oil rate, formation water rate, well operating pressure and current reservoir pressure.

6.3.2. Project surveillance techniques based on the monitoring procedures are

Continuous plots of watercut, oil rate and productivity index facilitate detection of wellbore impairment, improve ability to measure the effectiveness of wellbore stimulations, and improve ability to determine the impact of high volume lift installations. Inflow performance plots are used to optimize the design of high volume lift installations.


Reservoir withdrawal calculationsReservoir withdrawal calculations are made on at

least a monthly basis to determine any changes in reservoir voidage. Reservoir withdrawal calculations

i t t d i ll h f t fl dare important during all phases of waterflood operation.


For instance calculations during fill up time are important to maintain sufficient injection to production ratio. The injection rate should exceed the

d ti t b f t f th t fproduction rate by a factor of three to four. This ratio allows for a reasonable fill up time usually 1 to 1 years Once the optimum reservoir pressure1 to 1 years. Once the optimum reservoir pressure is achieved all pay is opened in all wells and fluid withdrawal rate is increased. During this period g preservoir withdrawal rate calculations are maintained to ensure that injection rates equal reservoir fluid rates.


BHP transient test analysis

Pressure transient test analysis is used to determine

Skin factors, kh product, p averages of water and oil banks and so on.


Injectivity plots with profile survey icomparisons

Injectivity plots (barrels injected per day per psi differential i j ti ) l ith i j ti fil l t dinjection pressure) couples with injection profile plots are used to detect injection well problems and injection well responses to stimulation, fracture treatment, and profile modification attempts.

The use of these injectivity plot with profile survey techniquesThe use of these injectivity plot with profile survey techniques coupled with chemical and transient pressure analysis can indicate injectivity problems associated with calcium carbonate scale bacteria o gen corrosion prod cts and oilcarbonate scale, bacteria, oxygen corrosion products and oil carryover.


Geochemical programGeochemical program uses all the monitoring p g g

procedures but special emphasis is placed on the chemical analyses of produced and injected water, well to well injection tracers, produced water salinity from all producers, H2S concentration in produced

il t ti i d d tgas oil carryover concentration in produced water.

6.3.2. Project surveillance techniques

All five of these primary surveillance techniques, 1. Productivity index and inflow performance plots, 2. Reservoir withdrawal calculations, 3. BHP transient test analysis, 4. Injectivity plots with profile survey comparisons and. jec v y p o s w p o e su vey co p so s d5. Geochemical program including tracer analysisenables us to carry out systematic well workovers on

d i d i j i ll Al b d hproducing and injection wells. Also based on the results of these techniques, frequently applied modifications in producing and injection policies maymodifications in producing and injection policies may produce favorable results in injection wells, producing wells and field production levels. p g p

V. Operate, monitor and evaluate waterflood ( A l l f l i )Actual Examples of Evaluation)

I i i i i h fl dIn many engineering organizations the waterfloodperformance of a project is predicted only once

h i h j i l d Thi i llat the time the project is planned. This is really unfortunate. The real pay-off in terms of i d i d fi bili dincreased recovery, increased profitability, and increased knowledge comes from a comparison

f h di d f f i i hof the predicted performance of a reservoir with the way it is actually behaving.

V. Operate, monitor and evaluate waterflood p ,(Actual Examples of Evaluation)

The following are three examples (borrowed from Craig) of some of the more common differences one observes between actual and predicted performance and what a study of these differences can tell us about how to improve our waterflooding operations.

V. Operate, monitor and evaluate waterflood(Ex.1)

Example datashows a plot ofpWOR versus

recovery. y

V. Operate, monitor and evaluate waterfloodp(Ex.1)

Previous figure shows a plot of WOR versus recovery. The smooth curve is that which was predicted at the outset of the project. The jagged curve is that actually observed. We see that water breakthrough has come earlier than predicted and in addition it seems to be rising generally at a faster rate than we predicted. What could be the causes of these differences?

V. Operate, monitor and evaluate waterflood( 1)(Ex.1)

First the reservoir may be more nonuniform than expected. That is in moving from the injection to producing well the injected water is contacting less of the reservoir and recovering less oil than we predicted. Perhaps the injected water is bypassing the oil by moving through a gas cap or an aquifer of formation fractures. Injectivityprofiles together with knowledge about the reservoir itself could help us tell whether we have a gas cap or aquifer bypassing.

V. Operate, monitor and evaluate waterflood(E 1)(Ex.1)

L ki h l i f ll i iLooking at the location of wells experiencing the higher than expected WOR may tell us

h h h i lwhether there are any reservoir scale fractures through which the water is

i A h ibili i h h i i i lmoving. Another possibility is that the initial gas saturation is higher than expected so h b i ll h i l il iblthat basically there is less oil possible to

recover by waterflooding.

V. Operate, monitor and evaluate waterfloodp(Ex.1)

R i i h d i hi f hReviewing the production history of the reservoir prior to waterflooding might give

l h h hi i iblus a clue as to whether this is a possible explanation. Another possibility is that the

il di l ffi i i l hoil displacement efficiency is lower than expected- perhaps due to selection of a non

i f l i bilirepresentative set of relative permeability characteristics.


This example illustrates how one would checkThis example illustrates how one would check the various factors that went into the reservoir performance prediction toreservoir performance prediction to determine the real cause for the difference in performance Some of the possible reasonsperformance. Some of the possible reasons for the difference, that is bypassing of the injected water through a gas cap couldinjected water through a gas cap could probably be remedied by injection well workoverworkover.

V. Operate, monitor and evaluate waterflood p ,(Ex.1)

If on the other hand the reservoir is more non uniform than expected or has a higher initial gas saturation , a comparison of actual and predicted performance might allow us to make a more realistic prediction for the future waterflood recovery.


The figureThe figure shows better performanceperformance than expected!


The previous figure shows the actual performance is more favorable than that which we predicted. Its true that we rather infrequently find this but a reservoir engineer should attempt to determine the reason for this difference also. Perhaps the reservoir is less heterogeneous than expected, or perhaps the crossflow of injected water between the different zones or layers in the reservoir has caused improved sweep.

V. Operate, monitor and evaluate waterflood p ,(Ex.2)

This may be an indication that the waterflood recovery from this project will be higher than that originally anticipated. In any event the reason for this difference is important.

V. Operate, monitor and evaluate waterflood (Ex.3)

The next figure (slide 21) shows the actual andThe next figure (slide 21) shows the actual and predicted oil producing rate from a waterflood project versus time Thewaterflood project versus time. The prediction had indicated an increased oil producing rate but the actual performanceproducing rate but the actual performance after showing an initial increase, has tended to level off and even begin a downwardto level off and even begin a downward trend.


Some possible reasons for this are that the water pinjection rate is lower than expected or perhaps the producing wells are becoming plugged by p g g p gg yparaffin or scale or may need larger pumps to maintain a reduced fluid level. This type of ypperformance also could be caused by a portion of the injected water entering a thief zone or j geven by the existence of a higher initial gas saturation than expected. p

V. Operate, monitor and evaluate waterflood(conclusion of examples)

A continuous evaluation of waterflood performance can accomplish several things. It can provide a basis for injection and production well workovers and thus for higher rates and increased daily income. The evaluation can lead to a modification of the flooding pattern and thus a higher recovery than might be ultimately obtained with the present pattern.

V. Operate, monitor and evaluate waterflood( l i f l )(conclusion of examples)

The comparision of actual and predicted waterfloodf l i ld i d i f hperformance can also yield an improved estimate of the

actual reservoir heterogeneity. It can al the least lead to a Better estimate of recovery performanceBetter estimate of recovery performance.

Thus to achieve maximum recovery the project y p jmust be well and continuously engineered.

Next are two special topics to be covered if time permits :

VI. Why waterfloods fail ?y

After discussing the design, surveillance and e al ation tools it ma be appropriate to pointevaluation tools it may be appropriate to point out some common reasons of why waterfloodsfailfail. Sometimes actual field performance does not match the predicted performance because ofmatch the predicted performance because of several reasons. Even before this failure issue there are major economic differences as athere are major economic differences as a result of average and exceptional waterfloods.


Waterfloods can fail primarily due to: Poor s eep efficienc Poor sweep efficiency

o Vertical permeability variations causing early breakthrough and high water productionbreakthrough and high water production

o Fractures and directional permeabilityo Fluid distribution in thick reservoirs with very y

high vertical permeability underruns the oilo Viscous fingering and unfavorable mobility

iratioo Unbalanced injectivity


Waterfloods can also fail due to: : Unexpected expenses

o Extensive remedial workE i f il d d d i fo Equipment failure and underdesign of producing and injection equipment

Oth Others o Initial oil saturations too small to form an oil

bankbanko Oil resaturation of gas cap

VII. Interwell tracers testing

Tracer tests deserve special attention for their role in Geochemical surveillance, identifying primary reasons why waterfloods fail and reservoir characterization and will be treated in the following.

ll d k i j iInterwell tracers are used to track injection fluid from injection wells to production wells.Th d d i i d iThe produced tracer timing and concentration can be used to deduce reservoir properties as h l f i l fl h Ththey relate to preferential flow paths. The use

of tracers to obtain some relevant information i i dis summarized as:


Continuation of sands and shales ( this canContinuation of sands and shales ( this can be achieved by selective injection of tracer into a given zone For instance if tracer isinto a given zone. For instance if tracer is injected in only one zone and is observed in a neighboring producer completed in aa neighboring producer completed in a different zone then the shale separating these zones is not continuous between thesethese zones is not continuous between these wells)

VII. Interwell tracers testingCharacterization of faults ( the absence of the

tracer production at an offset producer may p p ybe as a result of a fault between the injector and producer. Fig. E8) ) Note: ALL Figures in p g ) ) gTracer Section are borrowed from WaterfloodAsset Management book G. Takhur and coauthor

The flow along the fault zones are so high than h di i h lthe transverse direction thus early tracer

breakthrough may be detected at a producer h f lnear the fault.


Volumetric sweep efficiency at breakthrough The volumetric sweep efficiency at breakthrough is a measure of the seriousness of channeling because the amount of fluid injected towards a producer at the time of breakthrough provides some qualitative information on the volume of the high permeability channel. (see Fig. E11).


Breakthrough Efficiency


Delineation of flow barriers(Any type of flow restriction such as low permeability region between an injector and producer pair will reduce the movement of tracer to the producer.(See Fig. E9)


Delineation of flow barriers


Directional flow trends (On the other hand if (localized fractures are present in the reservoir early tracer breakthrough may occur. y g yPreferential flow paths can be ascertained by monitoring tracer breakthrough times at g gneighboring production wells in different directions from the injector. (See Fig. E10) j ( g )


Directional flow trends (cont):Breakthrough times are combined with pressure drops between wells to calculate the transmissibility. If preferential flow directions are present sweep efficiency could be improved by adjusting the pattern and/or flow rates. (See Fig. E10)

VII. Interwell tracers testingDirectional flow trends


Pattern balancing ( Pattern balancing is i i i i i h ffi iimportant in maximizing the sweep efficiency and ultimate recovery from a waterflood.

The relative amount of tracer recovered at h ll id i f h h feach well provide an estimate of how much of

the injected fluid flows towards each producer. Fi E12)Fig. E12)


Pattern balancing


Identification of problem injectors ( problem injectors can be identified b tagging theinjectors can be identified by tagging the injected fluid at each injector with a different tracertracer. As shown in Fig.E.13. early breakthrough at a producer can be attributed to flow from a givenproducer can be attributed to flow from a given injector.


Identification of problem injectors


Delineate between coning and channelingDelineate between coning and channeling(Water production at a well can be due to coning or channeling The channeling of theconing or channeling. The channeling of the injected fluid can be detected by tagging this fluid with a tracer )fluid with a tracer.)

Water Flood Design Surveillance Compatibility Mode

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