CRI Performance Optimization

Environmental friendly field development is a key target for Sakhalin Energy in this tough operating environment. During three years of cuttings injection in a Cuttings Re-injection (CRI) well, injection rate decreased twice, leading to two screen outs and consequent perforation of back-up zones. However domain capacity modeling indicated that injection of a bigger slurry volume should be possible contrary to reality. Using historical data records (injection pressure, volume and rate), and step rate injectivity test, an analysis was performed to understand what injection rate is a key parameter to optimize domain capacity. However the existing injection pumps (1 primary, and 1 backup) were limited to an optimal rate of 2 bpm each. Putting the two injection pumps in parallel made it possible to achieve the optimal injection rate of about 4 bpm, thereby lowering injection pressure, and making injection performance mimic domain model expectation.