东北石油大学学报2025，Vol.49Issue(3)：97-104,8.DOI:10.3969/j.issn.2095-4107.2025.03.008
复杂诱导裂缝网络注水直井试井模型及压力动态分析
Well testing model and pressure transient behavior analysis of water injection vertical wells with complex in-duced-fracture networks
摘要
Abstract
In low-permeability reservoirs,water injection in vertical wells usually generated complex in-duced fracture networks near the wellbore.These fractures are prone to closure during pressure buildup tests,making it difficult for existing well testing methods to achieve reliable inversion.Therefore,a semi-analytical pressure transient analysis model for water injection vertical wells with complex induced fracture networks is developed.The model couples the numerical solution of discretized fracture panels with the flow balance equation of each vertex to characterize fluid flow in complex fracture networks.Variable fracture storage is introduced to represent fracture closure behavior.By integrating the line-source function,Laplace transform,and Stehfest numerical inversion,the model achieves an efficient solution in such scenarios.The study clarifies the typical pressure transients of water injection vertical wells and quantifies the impact of key parameters.Finally,the model is validated through a field case application.The results demonstrate that the typical pressure transient curve can be divided into eight flow stages.The fracture closure effect generates a dual-well storage phenomenon,manifesting as a fracture storage stage and a second transition flow stage on the pressure derivative curve.The faster fracture closure rates lead to more pronounced"humps"on the curve.The secondary fractures create a fluid feed regime,where higher conductivity in these fractures results in deeper"dips"on the pressure response.The proposed well testing model effectively characterizes complex induced fracture networks around water injection wells and accounts for fracture closure during shut-in periods.Field applications confirm the model's practicality and accuracy,providing a reliable tool for parameter interpretation in such wells.关键词
注水直井/试井模型/诱导裂缝网络/裂缝闭合/压力动态分析/双井储效应Key words
vertical injection well/well testing model/induced fracture network/fracture closure/pres-sure transient analysis/dual-well storage effect分类
能源科技引用本文复制引用
崔永正,周文胜,姜瑞忠..复杂诱导裂缝网络注水直井试井模型及压力动态分析[J].东北石油大学学报,2025,49(3):97-104,8.基金项目
国家自然科学基金面上项目(52074347) （52074347）
中国海洋石油有限公司"十四五"重大科技项目(KJGG2021-0501) （KJGG2021-0501）
海洋油气高效开发全国重点实验室主任基金项目(KJQZ-2024-2101) （KJQZ-2024-2101）
