A Simplified Methodology on Selection, Operation, and Optimum Design of Steam Drive Reservoirs

摘要

Steam drive is a viable, proven technology for the development of heavy oil reservoirs. Prior to implementing the steam drive process, a prescreening strategy to evaluate the recovery potential is valuable. Meanwhile, the effect of operating conditions, the design techniques to satisfy specific operating conditions, and the management of any subsequent infill drilling programs in light of the steam drive history are all critical to successful steam drive projects. Based on numerical simulation and field cases, this paper provides some critical strategies and a simplified methodology for evaluating the steam drive process. Based on reservoir physical properties, a pre-screening formula is proposed for computing recovery factors that allow preliminary economic analyses to be performed. It is shown that a successful steam drive project must satisfy the following four operating criteria: 1. Steam injection rate is 1.6 to 1.8 m~3/(d·ha·m); 2. Production injection ratio is greater than or equal to 1.2; 3. Bottom hole steam quality is greater than 40%; and, 4. Reservoir fluid pressure is maintained below 5 MPa. A design methodology is also provided, which can provide information on the most effective well pattern (5-spot, inverted 7-spot, and inverted 9-spot) and well spacing in order to satisfy the above four criteria. The sensitivity of the methodology to the injectivity/productivity estimates is also discussed.