深层页岩气井气水两相缝网参数反演方法  

Inversion method for deriving fracture network parameters in deep shale gas well considering gas-water two-phase flow

作　　者：张娇娇 黄世军[1] 赵凤兰[1] 方思冬 ZHANG Jiaojiao;HUANG Shijun;ZHAO Fenglan;FANG Sidong(College of Petroleum Engineering,China University of Petroleum-Beijing,Beijing 102249,China;Petroleum Exploration&Production Research Institute,SINOPEC,Beijing 100083,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]中国石化石油勘探开发研究院,北京100083

出　　处：《石油科学通报》2024年第3期487-502,共16页Petroleum Science Bulletin

基　　金：国家自然科学基金项目“页岩储层条件下水对甲烷—二氧化碳竞争吸附的影响及相互作用机制研究”(51974328)和国家自然科学基金—联合基金项目“深层页岩气开发动态评价与数值模拟方法研究”(U19B6003-03-05)联合资助。

摘　　要：深层页岩气藏的开发离不开大规模的体积压裂技术,而缝网参数反演方法是压裂效果评价、产能动态分析的一种重要手段。现有的缝网参数反演方法忽略了支撑剂不均匀分布和气水两相渗流对深层页岩气藏开发的影响,导致参数反演误差较大,且难以区分“近井支撑裂缝”和“远井未支撑裂缝”对产能的贡献。针对这一问题,基于动态分析方法,建立了考虑多重非线性流动机理和未完全支撑裂缝的深层页岩储层气水两相缝网参数反演方法。反演方法建立过程中基于线性流模型假设,将压后的复杂裂缝网络等效为支撑裂缝区、压裂改造内区、未支撑裂缝区和压裂改造外区4个区域,采用变量替换、摄动变换、逐次替换等手段处理气体高压物性参数、超临界吸附、应力敏感、非达西渗流和气水两相渗流引起的非线性。利用数值模拟模型验证了本文方法的可靠性,并选取四川盆地4口深层页岩气井进行了应用分析。结果表明,建立的深层页岩气水两相缝网参数反演方法考虑了气液同产对产能预测和参数反演的影响,实现了支撑与未支撑裂缝半长和渗透率等参数的定量区分,为准确计算深层页岩气产量、评价压裂效果提供了理论指导。Deep shale formations are so tight and low permeable that large-scale hydraulic fracturing technology is used to increase production to achieve economic development,and the inversion method of fracture network parameters is an important means of evaluation of hydraulic fracturing performance and gas well productivity analysis.The existing fracture network parameter inversion methods do not consider the influence of uneven distribution of proppant in fractures and gas-water two-phase seepage on the development of deep shale gas reservoirs after hydraulic fracturing,resulting in considerable error in parameter inversion,and it is difficult to distinguish the contribution of“near-well propped fractures”and“far-well unpropped fractures”to productivity.To solve this problem,based on the dynamic analysis method,a gas-water two-phase fracture network parameter inversion method is established for deep shale gas reservoirs considering multiple nonlinear flow mechanisms and incompletely propped fractures.In the inversion method of fracture network parameters,based on the assumption of the linear flow model,the complex fracture network formed after hydraulic fracturing is equivalent to four areas:propped artificial fracture,fracture stimulated inner formation,unpropped artificial fracture and fracture stimulated outer formation.Variable substitution,perturbation transformation,and successive substitution are used to deal with the nonlinearity caused by high-pressure gas physical parameters,supercritical adsorption,stress sensitivity,non-Darcy seepage and gas-water two-phase seepage.The reliability of the method is verified by numerical simulation,and four deep shale gas wells in the Sichuan Basin are selected for application analysis.The results show that the parameter inversion method established considers the influence of gas-water co-production on productivity prediction and parameter inversion,and can quantitatively distinguish between propped and unpropped fractures with parameters such as half-length and perme

关 键 词：深层页岩气 未完全支撑裂缝 气水两相流动 缝网参数反演 动态分析方法 

分 类 号：TE328[石油与天然气工程—油气田开发工程] P642.3[天文地球—工程地质学]