Marco R. Thiele and Rod P. Batycky SPE ATCE Denver, CO – October 2003 SPE 84040 Water Injection Optimization Using a Streamline-Based Workflow Marco R. Thiele and Rod P. Batycky StreamSim Technologies —Special thanks you to Nobuo Nishikiori, Arabian Oil Company, for field data set.—

Outline Objectives and introduction to streamline simulation. The seed: additional data supplied by streamlines. Waterflood optimization. A workflow. Example application.

Introduction – Biz Objectives Business objectives: grow production, reserves, cash flow Make and execute decisions Strategies & recommendations Develop/obtain knowledge Synthesis and analysis Performance Tools (simulation) Obtain and use key data People Performance Tools Analogues Decline Curve Analysis Material Balance/Type Curve Analysis Streamline Simulation Finite Difference Simulation Integrated Production Modeling Increasing complexity,time, skill, knowledge (after Pande 2003)

Introduction—Streamline Sim. Solve transport problem along 1D streamlines rather than on an underlying 3D computational grid. Efficient solution of transport problemfiner grids, speed but also visualization & new data. Geology Pressure Streamlines Compositions (From Y. Gautier et al., 1999)

Modern Streamline Simulation SL’s are traced in 3D. Conservation equations along SL’s are in terms of TOF. SL’s are updated in time to reflect changing reservoir conditions. Numerical 1D solutions along SL’s. Gravity Compressibility

The seed—New Data from SL’s Streamlines are able to quantify injector/producer relationships:

The seed—Flux Pattern Map

The seed – 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.

The seed – Injection Efficiency Injection efficiencies can be used to automatically identify well pairs with extreme water cycling. Oil Produced Water Injected

Waterflood Optimization Objectivebest 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.

Waterflood Optimization Once well pairs are identified, use a weighting function to decide how much volume to shift from low to high efficiency injectors.

Workflow t,q Calculate efficiencies using last know rates. t,qn+1 Re-allocate rates using weights from equation. t+Dt,qn+1 Simulate forward by Dt using new rates.

Waterflood Optimization

Middle Eastern Limestone Res. Compressible SL simulation 8 producers / 5 injectors Acceptable HM Objective: plan future water injection.

Middle Eastern Limestone Res. SL’s by Injectors SL’s by Producers

Flux Pattern Map by Injectors (beginning of optimization) Middle Eastern Limestone Res. Flux Pattern Map by Injectors (beginning of optimization)

Flux Pattern Map by Injectors (end of optimization – 5 years) Middle Eastern Limestone Res. Flux Pattern Map by Injectors (end of optimization – 5 years)

Middle Eastern Limestone Res. 10 optimization steps (6 months /step) T + 5 Years

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

Middle Eastern Limestone Res. Optimized Period Not optimized Oil Optimized Water

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 automaticability to optimize large fields/many wells.

Thank you.