克拉玛依砾岩油田注水开发特征

DEVELOPMENT CHARACTERISTICS OF THE WATER FLOODED KARAMAY CONGLOMERITIC OIL RESERVOIR

克拉玛依油田储层以山麓洪积相砾岩沉积为主。含油砾、砂岩体一般分布范围小,连通性差,平面、剖面上岩性、物性变化大,渗透率低。微观非均质严重,储层具有多级支撑结构,粘土含量高。孔隙类型多,结构复杂,分选很差。其注水开发特征是注采能力低,油井注水增产效果见水状况差别大,水驱控制储量增加困难,驱油效率不高,最终采收率较低。但是开发过程中,采用了密井网、面积注水,实行了多井少注(增多注水井点,控制单井注水量)、温和注水、强化开采的方针,合理配置油层能量,加强油井改造工作,不断提高排液量,因而改善了砾岩油田的开发效果。

The reservoir formation of Karamay oil field is mainly a fluvial phase conglomeratic rock oil bearing conglomeratic and sand-bodies are small in size generally, with poor continuity, highly variable in lithological and petrophysical properties both vertically and laterally, low permeability and highly heterogeneous and anisotropic microscopically. The reservoir rocks are characterized by multiple mouldic, multiple pore types, complex pore structure, and poor sorting. The development features are characterized by low well productivity and injectivity, large difference on the effects of water injection to the productivity and water breakthrough in production wells, low percentage of reserve affected by water injection, low water oil displacement efficiency as well as low recovery factor. According these features, technical measures, such as closely spaced well pattern, pattern flooding, high injection production well ratio with controlled injection rate at each well, production of wells being enhanced by well stimulation, and a reasonable balance of reservoir energy, have been taken, so that the results of development are highly improved.