压裂液返排率影响因素的实验研究  

Experimental study on factors affecting backflow rate of fracturing fluid

作　　者：王方祥 孙立波 赵阳 臧春雷 刘晓旭 刘宗奇 WANG Fangxiang;SUN Libo;ZHAO Yang;ZANG Chunlei;LIU Xiaoxu;LIU Zongqi(Downhole Technical Services Branch,Bohai Drilling Engineering Company Limited,CNPC,Tianjin 300283;Downhole Operation Branch,Dagang Oilfield Company,PetroChina,Tianjin 300280)

机构地区：[1]中国石油渤海钻探工程有限公司井下技术服务分公司,天津300283 [2]中国石油大港油田公司井下作业分公司,天津300280

出　　处：《长江大学学报（自然科学版）》2023年第1期72-79,共8页Journal of Yangtze University(Natural Science Edition)

基　　金：国家科技重大专项“页岩气水平井压后裂缝参数评价”(2016ZX05060001-032);中国石油科技开发项目“长宁页岩气深层工厂化压裂提效技术推广”(2020T-002-007);中国石油重大研发项目“大港油田工厂化压裂试油完井技术研究”(2019ZD14Y-03)。

摘　　要：针对压裂液返排率较低的问题,利用无量纲分析方法,推导了与现场工况相对应的实验无量纲时间,开展了压裂液返排的三维模型实验,研究了驱替方向、地层压力、界面张力、压裂液黏度和支撑剂润湿性对返排率的影响规律。结果表明,驱替方向与重力方向相同时,压裂液的最终返排率最高;驱替方向与重力方向相反时,由于出现指进现象,导致最终返排率较低。因此,应通过调整压裂液性能尽量避免指进现象的出现。压裂液的最终返排率随地层压力的升高而降低,稳定的地层压力更有利于压裂液的返排,压裂施工后需利用合适直径的油嘴控制压裂液返排。压裂液的最终返排率随界面张力的下降而上升,但上升趋势逐渐变缓,随液体黏度的增加而降低。亲油性的支撑剂更有利于压裂液的返排。Aiming at the problem of low backflow rate of fracturing fluid, dimensionless analysis method was used to deduce the dimensionless experimental time corresponding to the field working conditions, and three-dimensional model experiments of fracturing fluid backflow were carried out to study the influence of displacement direction, formation pressure, interfacial tension, fracturing fluid viscosity and proppant wettability on backflow rate.The results show that when the displacement direction is the same as the gravity direction, the final backflow rate of fracturing fluid is the highest, and when the direction is opposite to the gravity direction, the final backflow rate is lower due to the fingering phenomenon.Therefore, the fingering phenomenon should be avoided by adjusting the performance of fracturing fluid.The final backflow rate of fracturing fluid decreases with the increase of formation pressure, and the stable formation pressure is more conducive to the backflow of fracturing fluid.After fracturing construction, oil nozzle with appropriate diameter should be used to control fracturing fluid backflow.The final backflow rate of fracturing fluid increases with the decrease of interfacial tension, but the upward trend gradually slows down and decreases with the increase of liquid viscosity.The lipophilic proppant is more conducive to the backflow of fracturing fluid.

关 键 词：压裂液 返排率 无量纲时间 影响因素 实验研究 

分 类 号：TE35[石油与天然气工程—油气田开发工程]