© 2003 by Streamsim Technologies

Marco R. Thiele and Rod P. BatyckyStreamSim Technologies

—Special thanks you to Nobuo Nishikiori, Arabian Oil Company, for field data set.—

Water Injection Optimization Using a Streamline-Based Workflow

SPE ATCE Denver, CO – October 2003 SPE 84040

© 2003 by Streamsim Technologies

Outline

1. Objectives and introduction to streamline simulation.

2. The seed: additional data supplied by streamlines.

3. Waterflood optimization.

4. A workflow.

5. Example application.

© 2003 by Streamsim Technologies

Introduction – Biz Objectives

Analogues Decline Curve Analysis Material Balance/Type Curve Analysis Streamline Simulation Finite Difference Simulation Integrated Production Modeling

Develop/obtain knowledge

Synthesis and analysis

Performance Tools (simulation)Obtain and use key data

People

Business objectives: grow production, reserves, cash flow

Make and execute decisions

Strategies & recommendations

(after Pande 2003)

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Performance Tools

© 2003 by Streamsim Technologies

Introduction—Streamline Sim.

(From Y. Gautier et al., 1999)

Geology Pressure Streamlines Compositions

Solve transport problem along 1D streamlines rather than on an underlying 3D computational grid.

Efficient solution of transport problemfiner grids, speed but also visualization & new data.

© 2003 by Streamsim Technologies

Modern Streamline Simulation1. SL’s are traced in 3D.

2. Conservation equations along SL’s are in terms of TOF.

3. SL’s are updated in time to reflect changing reservoirconditions.

4. Numerical 1D solutions along SL’s.

5. Gravity

6. Compressibility

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© 2003 by Streamsim Technologies

The seed—New Data from SL’s• Streamlines are able to quantify

injector/producer relationships:

© 2003 by Streamsim Technologies

The seed—Flux Pattern Map

© 2003 by Streamsim Technologies

The seed – Injection Efficiency

• Injection Efficiency:

• Ieff for injector or for each producer-injector pair; changes with time.

• Works as a ratio of rates (instantaneous) or cumulative volumes (average)

• Can be used for any injection volume type.

off-set oil production [rb/day]

water injection [rb/day]effI

© 2003 by Streamsim Technologies

• Injection efficiencies can be used to automatically identify well pairs with extreme water cycling.

Water Injected

Oil

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The seed – Injection Efficiency

© 2003 by Streamsim Technologies

Waterflood Optimization

• Objectivebest use of injected volumes• …for displacement purposes, not re-

pressurization.

• Increase rates in “high” efficiency connections, decrease rates in “low” efficiency connections.

• Must increase/decrease rates at both producers

and injectors.

© 2003 by Streamsim Technologies

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Waterflood Optimization• Once well pairs are identified, use a weighting

function to decide how much volume to shift from low to high efficiency injectors.

© 2003 by Streamsim Technologies

Workflow

Calculate efficiencies using last know rates.

Re-allocate rates using weights from equation.

Simulate forward by t using new rates.

t,q

t,qn+1

t+t,qn+1

© 2003 by Streamsim Technologies

Waterflood Optimization

© 2003 by Streamsim Technologies

Middle Eastern Limestone Res.

• Compressible SL simulation

• 8 producers / 5 injectors

• Acceptable HM

• Objective: plan future water injection.

© 2003 by Streamsim Technologies

Middle Eastern Limestone Res.

SL’s by Injectors SL’s by Producers

© 2003 by Streamsim Technologies

Middle Eastern Limestone Res.

Flux Pattern Map by Injectors(beginning of optimization)

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Middle Eastern Limestone Res.

Flux Pattern Map by Injectors(end of optimization – 5 years)

© 2003 by Streamsim Technologies

Middle Eastern Limestone Res.

10 optimization steps (6 months /step)

T

T + 5 Years

© 2003 by Streamsim Technologies

Middle Eastern Limestone Res.

• Streamline simulation a complementary tool to finite difference simulation

• Take optimized reservoir rates from SL’s and feed to finite-difference simulator:

Analogues Decline Curve Analysis Material Balance/Type Curve Analysis Streamline Simulation Finite Difference Simulation Integrated Production Modeling

Performance Tools

© 2003 by Streamsim Technologies

Optimized Period

Optimized

Not optimized

Middle Eastern Limestone Res.

Oil

Water

© 2003 by Streamsim Technologies

Conclusions

• Streamlines offer a powerful new way to optimize flooding operations:• Well allocation data• Flux Pattern Map

• Streamlines complementary to more traditional simulation approaches.

• Procedure is automaticability to optimize large fields/many wells.

© 2003 by Streamsim Technologies

Thank you.