基于双裂缝滤失模型的水力压裂数值模拟  

Numerical Simulation of Hydraulic Fracturing with a Two-fracture Leak-off Model

作　　者：周鹏 周龙 龙杨忠 赵宁致 安松松 邱乐天 龙恭博 ZHOU Peng;ZHOU Long;LONG Yangzhong;ZHAO Ningzhi;AN Songsong;QIU Letian;LONG Gongbo(School of Mechanical and Electrical Engineering,Wuhan Institute of Technology,Wuhan Hubei 430205)

机构地区：[1]武汉工程大学机电工程学院,湖北武汉430205

出　　处：《湖北理工学院学报》2025年第2期9-14,共6页Journal of Hubei Polytechnic University

基　　金：国家自然科学基金项目(项目编号:52004183);湖北省教育厅重点项目(项目编号:D20201505);武汉工程大学第十五届研究生教育创新基金项目(项目编号:CX2023214)。

摘　　要：滤失决定了水力裂缝的最终形状尺寸,是影响水力压裂效果的关键因素之一。当前,石油工业界广泛运用不考虑水力裂缝间滤失相互影响的一维卡特模型来量化滤失。然而,在密排水力压裂数值模拟中,由于水力裂缝间距较小,裂缝间滤失相互影响显著,使用该模型会降低模拟精度。文章从一维渗流基本控制方程出发,结合达西定理推导出考虑裂缝间相互影响的双裂缝滤失模型。通过对比卡特模型和双裂缝模型的计算结果,验证了双裂缝模型的精确性。将双裂缝滤失模型嵌入FrackOptima全三维水力压裂模拟软件,建立算例开展密排水力压裂数值模拟研究。结果表明:在传统压裂参数范围内,两个模型计算结果相差不超过1%;但在非常规密排压裂工况下,参数取值超出传统范畴,必须使用双裂缝滤失模型。在密排压裂算例参数条件下,能获得较均匀多簇裂缝发育的最小簇间距为10 m。Leak-off is one of the key factors determining the final shape and size of hydraulic fractures and thus affecting the results of hydraulic fracturing.Currently,the one-dimensional Carter′s model is widely used in the petroleum industry to quantify leak-off,but this approach does not consider the interaction of leak-off between hydraulic fractures which will reduce the simulation accuracy due to the significant leak-off from small spacing between hydraulic fractures..This study establishes a novel dual-fracture leak-off model through analytical derivation of 1D seepage governing equations coupled with Darcy′s law,explicitly accounting for fracture-to-fracture interactions.The accuracy of the two-fracture model was verified by comparing the two models.The two-fracture leak-off model was incorporated into the FrackOptima fully three-dimensional hydraulic fracturing simulation software,and numerical examples were established to conduct numerical simulation research on closely-spaced hydraulic fracturing.Comparative validation against Carter′s model predictions demonstrates less than 1%deviation under conventional fracturing conditions.However,under unconventional closely-spaced fracturing conditions,when the parameter values exceed the traditional range,the two-fracture leak-off model must be used.Under the parameter conditions of the closely-spaced fracturing numerical example in this paper,computational analysis identifies 10 m as the minimum cluster spacing threshold for achieving uniform multi-cluster fracture propagation under optimized stimulation parameters.

关 键 词：滤失 卡特模型 双裂缝滤失 水力压裂 数值模拟 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]