强水敏低渗砂砾岩油藏压裂技术应用研究

APPLIED RESEARCH OF FRACTURING TECHNOLOGY FOR STRONG WATER-SENSITIVE AND LOW PERMEABILITY GLUTINITE RESERVOIR

新疆油田288断块低孔低渗储层属辫状河流沉积砂砾岩,必须采取压裂改造才能有效开发。试注资料显示本区储集层存在强水敏性。在288断块储层特征分析的基础上,有针对性地开展了储层敏感性实验、压裂液性能测试、岩石力学及支撑剂嵌入测试等室内评价实验,并对该断块前期压裂井进行了评估分析,为后续压裂设计提供了重要依据。开展了压裂裂缝规模优化研究,以长期采收率和压裂初期采出程度为主要的评价指标,优化了288断块的压裂裂缝规模。在室内实验和理论研究的基础上,特别是为解决油藏的强水敏性和低温压裂的破胶问题,提出了直接采用稠油作为携带液的原油压裂工艺技术。依据压裂优化方案原则,现场实施近20口井取得了良好的增产效果,为解决强水敏地层压裂改造提供了新的技术思路,对类似油藏的压裂具有指导意义。

288 block reservoir with low permeability in Xinjiang oilfield pertains to braided stream sedarenite, and it must take hydraulic fracturing in order to develop effectively. Injection test reveals that the formation is strong water sensitivity. Based on the analysis of reservoir characteristics of 288 block, we have done some targeted indoor experiments including reservoir sensitivity experiments, fracturing fluid performance test, reservoir rock mechanics and proppant embedment test, and evaluated the antecedent fracturing wells which provided some important basis for the follow-up fracturing wells. Besides, in order to optimize fracture scale of 288 block, a optimization study of fracture scale was carried out by taking long-term recovery ratio and fracture initial production rate as the major evaluating indicator. On the basis of indoor experiments and theoretical studies, in particular to solve the reservoir strong water sensitivity and cracking of low temperature fracturing, a kind of crude oil fracturing technics was put forward which uses viscous crude as carrier fluid. Based on the principle of Fracturing optimization program, nearly 20 fracturing wells have obtained good stimulation effect, so it provides a new idea for fracturing of strong water sensitivity reservoir and similar reservoir.