海上复杂断块油田合理注水压力研究

Study on reasonable water injection pressure of offshore complex fault-block oilfield

合理注水压力是海上注水开发复杂断块油田控制地质性溢油风险的关键参数,根据复杂断块油藏特点制定合理注水压力,对实现海上复杂断块油田安全高效开发意义重大.文中重新定义了复杂断块油田合理注水压力,综合考虑地层破裂压力和断层临界失稳压力,利用渗流力学理论及数值模拟技术,研究出与“通海底”断层不同距离、不同注采关系下注水井的合理注水压力为15.9～22.4MPa,并根据研究结果提出了注水井井位设计建议.该研究在渤海蓬莱油田注水管理中取得了较好的应用效果,可以为海上其他复杂断块油田的安全注水管理提供参考.

Reasonable water injection pressure is the key point for offshore complex fault-block oilfield by waterflooding development to control the risk of geological oil spill,so it is significant to figure out reasonable water injection pressure and to develop the oilfield with safety and high efficiency according to the characteristics of complex fault-block reservoir.This article redefined the reasonable water injection pressure of complex fault-block oilfield,comprehensively considered formation fracture pressure and the critical buckling pressure of fault,and studied the well pattern and the distance of injection well to the faults reaching seafloor using seepage flow theory and numerical simulation method.The reasonable water injection pressure of 15.9-22.4 MPa was figured out.The suggestion for the location design of injection well was given based on the research result.The study results were applied in the waterflooding management of Penglai Oilfield in Bohai Bay,getting a good effect,which can provide a reference for safe waterflooding management of other offshore complex fault-block oilfield.