基于最优裂缝导流能力的水平井压裂后生产指数预测新方法  

A new prediction method for postfracturing productivity index of horizontal well based on optimal fracture conductivity

作　　者：纪国法[1,2] 王晓燕[1,2] 南晨阳 刘文涛[3] 刘进 JI Guofa;WANG Xiaoyan;NAN Chenyang;LIU Wentao;LIU Jin(Cooperative Innovation Center of Unconventional Oil and Gas(Ministry of Education&Hubei Province),Yangtze University,Wuhan 430100,China;Key Laboratory of Drilling and Production Engineering for Oil and Gas,Yangtze University,Wuhan 430100,China;Research Institute of Exploration and Development,PetroChina Xinjiang Oilfield Company,Karamay 834000,China;No.8 Oil Production Company of PetroChina Changqing Oilfield Company,Xi’an 710018,China)

机构地区：[1]长江大学非常规油气省部共建协同创新中心,湖北武汉430100 [2]长江大学油气钻采工程湖北省重点实验室,湖北武汉430100 [3]中国石油新疆油田公司勘探开发研究院,新疆克拉玛依834000 [4]中国石油长庆油田公司第八采油厂,陕西西安710018

出　　处：《大庆石油地质与开发》2023年第6期59-66,共8页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家自然科学基金项目“基于分形理论及多尺度方法的页岩体积改造压裂液滤失机理研究”(51804042);油气资源勘探技术教育部重点实验室(长江大学)青年创新团队项目“页岩气水平井重复压裂关键技术”(PI2021-04);非常规油气省部共建创新中心(长江大学)开放基金项目“考虑页岩弱结构面的人工裂缝穿层延展机理研究”(UOG2022-38)。

摘　　要：生产指数是水平井压裂后生产能力评价的重要指标,目前非常规油气水平井压裂后产能预测方法较复杂,参数较多,需进一步优化设计。基于统一压裂设计理论的支撑剂指数法,借用支撑裂缝流动效率优化无因次裂缝导流能力及无因次生产指数,采用多元线性回归方法建立了水平井长度、裂缝半长、裂缝条数、井控边界、储层厚度5种因素影响下的最优无因次裂缝导流能力及无因次生产指数计算模型。结果表明:利用新建模型回归的最优无因次裂缝导流能力多元线性方程决定系数R2为0.933,回归的无因次生产指数多元线性方程决定系数R2为0.980,平均相对误差均小于5%,与传统预测方法相比,精度有了明显的提高。敏感性分析结果表明,生产指数与水平井长度、裂缝条数、裂缝半长和储层厚度呈正相关,与矩形渗流区域长度呈负相关,其中与裂缝条数的关联性最强。研究成果对快速实现非常规油气水平井压裂后产能准确预测、经济评价和施工参数优化都具有重要意义。Productivity index is an important index for evaluating postfracturing productivity of horizontal wells.Current methods of postfracturing productivity prediction for unconventional oil and gas horizontal wells are complex with many parameters and need further optimization.Based on proppant index method of unified fracture design theory,dimensionless fracture conductivity and dimensionless productivity index are optimized with the help of propped fracture flow efficiency,and the optimal dimensionless fracture conductivity and dimensionless production index calculation model influenced by 5 factors of horizontal well length,fracture half-length,number of fractures,well controlled boundary and reservoir thickness is established by using multiple linear regression method.The results show that new-established model in this paper gets regressed determination coefficient R2=0.933 of multi-linear equation of optimal dimensionless fracture conductivity,and determination coefficient R2=0.980 of multi-linear equation of regression dimensionless productivity index,with average relative error of<5%,and compared with traditional prediction methods,the accuracy is improved obviously.Sensitivity analysis shows that productivity index is positively correlated with the length of horizontal wells,the number of fractures,half-length of fractures and reservoir thickness,and negatively correlated with the length of rectangular seepage area,with the most correlation with the number of fractures.The research provides much significance for rapid realization of accurate productivity prediction,economic evaluation and operation parameters optimization of unconventional oil and gas horizontal wells after fracturing.

关 键 词：水平井 分段压裂 裂缝导流能力 统一压裂设计 生产指数 

分 类 号：TE357[石油与天然气工程—油气田开发工程]