H区块缝洞单元连通方式及注水开发对策研究

针对H区块缝洞型油藏连通单元井组实施注水驱替开发效果差异很大这一问题，开展了缝洞单元连通方式及注水开发对策研究。利用地球物理方法对微裂缝、大尺度裂缝、有效基质、孔洞进行刻画，提出了3种缝洞单元连通方式：暗河岩溶管道、大尺度缝、弥散缝伴有大尺度缝。对不同的缝洞连通单元开展机理性数值模拟和矿场试验研究，给出合理的注水开发对策。暗河体系具有连通井组低注高采、洞注暗河驱洞采的注采关系；弥散缝伴有大尺度缝，沟通缝洞单元，不同单元二者匹配具有差异性，应控制合理的注采比，后续动态调整，提高注水开发采收率，改善区块连通单元注水驱替效果，对相同或类似缝洞型碳酸盐岩油藏连通单元注水开发具有一定的借鉴及指导意义。

Study on the Connection Type of Fracture-cavity Unit in H Block and Water Flooding Development Strategy

There is a significant difference in the development effect of water flooding displacement of well groups in fracturecavity reservoir units of H blocks. This study conducted research into the connection type of fracture-cavity units and water flooding development strategy. A geophysical method was used to describe micro-fracture, large-scale fracture, effective matrix, and pores, based on which three connection types of fracture-cavity unit were proposed:underground river karst conduit, largescale fracture, and dispersed fracture with large-scale fracture. Moreover, numerical simulation of and field test research on different fracture-cavity connection units were conducted; a rational water flooding development strategy was developed. The underground river system featured an injection-production relationship of low-injection high-production and cavity-injection underground river displacement production. For different units, there are differences in the matching of dispersed fracture with large-scale fracture and fracture-cavity connection units. As a result, it is advisable to take rational control over the injectionproduction ratio with follow-up dynamic adjustment to improve the recovery ratio of water flooding development and the water flooding displacement effect of connecting units in the block. This study is of reference and guiding significance for the same or similar water flooding development of connected units of fracture-cavity karst reservoirs.