致密油藏分段多簇压裂水平井复杂缝网表征及产能分析  

Complex fracture network characterization and productivity analysis of multistage fractured horizontal well in tight oil reservoirs

作　　者：徐加祥 丁云宏[1] 杨立峰[2,3] 高睿 刘哲 王臻 XU Jiaxiang;DING Yunhong;YANG Lifeng;GAO Rui;LIU Zhe;WANG Zhen(PetroChina Research Institute of Petroleum Exploration & Development,Beijing City,100083,China;Fracturing and Acidification Service Center of PetroChina Research Institute of Petroleum Exploration & Development,Langfang City,Hebei Province,065007,China;CNPC Key Laboratory for Reformation of Oil and Gas Reservoirs,Langfang City,Hebei Province,065007,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油勘探开发研究院压裂酸化技术服务中心,河北廊坊065007 [3]中国石油油气藏改造重点实验室,河北廊坊065007

出　　处：《油气地质与采收率》2019年第5期132-138,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家油气重大专项“致密油储层高效体积改造技术”(2016ZX05046-004)

摘　　要：致密油藏多采用水平井分段多簇压裂方式生产,产能预测需兼顾天然裂缝和水力裂缝的分布,同时考虑裂缝与基质之间的耦合。以S油田天然裂缝的走向和密度为基础,利用COMSOL和MATLAB软件联合仿真技术,对致密油藏中水平井井筒、水力裂缝和天然裂缝的分布进行建模。利用基质-裂缝-井筒耦合流动模型,模拟了水力压裂条件下,不同裂缝间距和裂缝长度油藏的压力分布、日产油量和累积产油量。结果表明:水力压裂改造后,压力首先波及到导流能力较强的主裂缝和次级裂缝,随后向沟通的天然裂缝和基质扩展,且扩展速度逐渐变缓;对于无法连通的未改造区域,压力很难波及到。生产时间为1000d时,压力波及区域面积仅为油藏面积的34.1%。增加裂缝长度及减小裂缝间距均可提高日产油量和累积产油量,其中减小水力裂缝间距对提高产能和累积产量的贡献更为显著。Most tight oil reservoirs are put into production by multistage fractured horizontal well,and the distribution of the natural fractures and hydraulic fractures,and the coupling of the fractures and matrix should be considered in the productiv ity analysis. A model of the horizontal wellbore,and the distribution of the hydraulic fractures and natural fractures is pro posed by the COMSOL and MATLAB program based on the real data of the fracture strike and density in S Oilfield. The pressure distribution,daily oil production and cumulative oil production under the different lengths and spacing of hydrau lic fractures are simulated by the matrix-fracture-wellbore coupling flow model. The results show that the pressure drops can be firstly observed in the main fractures and secondary fractures with higher conductivity,and then pressure drops spread to the natural fractures and matrix slowly. Pressure drop is hard to spread to the unstimulated and disconnected res ervoir regions. The low-pressure area accounted for 34.1% of the whole reservoir area when the production time is 1 000 days. Increasing fracture length and decreasing fracture spacing are helpful to the improvement of both daily and cumula tive oil production. Decreasing the fracture spacing is a more effective way to increase the daily oil production so that the cumulative oil production is improved significantly.

关 键 词：致密油藏 天然裂缝 体积压裂 基质-裂缝-井筒耦合流动 产能模拟 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]