Reservoir conformance approach and management practices for improved recovery opportunities: Process and case history

The realization that the majority of the world's reserves exist in mature reservoirs has resulted in new urgency to develop methods to resolve excessive water production and improve recovery efficiency. Predicting water influx problems, selecting candidate wells for water control treatments, and justifying expenditures are critical factors for developing improved reservoir management strategies. Optimum reservoir management strategies begin with an understanding of fluid flow behavior in the reservoir under both production and injection conditions. This understanding allows for the creation of conceptual models that illustrate the flow of fluids in reservoirs and serve as a means of communicating management strategies to all participating in operations and business functions. This concept emphasizes the use of the total reservoir approach. This paper will present a technique that uses reservoir description to develop management strategies for improved reservoir recovery through application of conformance technology. "Conformance" - as used here - may be defined as the management and alteration of water and gas flows using the appropriate reservoir understanding to optimize hydrocarbon production. This approach clearly emphasizes the importance of forming multi-disciplinary teams to resolve excess water production problems. The teams are not only multi-disciplinary but also multi-company, including personnel from both the operating and service companies. The goals of the teams should be to: • Build a reservoir model that incorporates the static and dynamic properties of the reservoir • Validate the model • Use the model to illustrate the fluid movement in the reservoir • Develop a strategy for managing excessive water production • Select treatment candidates • Implement the strategy • Evaluate results. The application of this "total" approach is illustrated with a case history. In this case history, reservoir data are discussed, and a conceptual model that describes a problematic water flow mechanism is developed. This model is then used to develop a reservoir management strategy that incorporates conformance technology to improve the existing recovery factor of 9.5% to an expected recovery factor of 40%.