注液方案对水力裂缝扩展影响的数值模拟  

Numerical simulation study on the influence of injection scheme on hydraulic fracture propagation

作　　者：左通 李严严 张梦雅 贺昱杰 ZUO Tong;LI Yanyan;ZHANG Mengya;HE Yujie(Faculty of Urban Construction,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市建设学部,北京100124

出　　处：《石油地质与工程》2025年第1期114-118,122,共6页Petroleum Geology and Engineering

基　　金：国家自然科学基金面上项目“鄂尔多斯盆地陆相页岩储层复杂缝网成生演化机制与可压裂性评价研究”(42077258)。

摘　　要：由于在压裂过程中水力裂缝与天然裂缝相互作用,影响储层改造效果,注液方案对水力裂缝扩展的影响也较大,明确注液方案对水力裂缝扩展的影响规律对致密砂岩气开发具有重要意义。基于无人机摄影测量技术对天然裂缝数据进行提取,建立了鄂尔多斯盆地延长组致密砂岩地层的二维数字模型,将二维数字模型导入ABAQUS有限元软件中,采用全局嵌入cohesive单元的方法开展了三种注液方案下的水力压裂数值模拟。结果表明,采用恒定幅值的脉冲注液能够明显提高水力裂缝的长度和高度;通过变幅值的脉冲注液可以实现降低破裂压力的效果;水力裂缝扩展压力与注入速度的变化趋势高度一致;水力裂缝扩展过程中岩石的破坏模式以拉伸破坏为主。Due to the interaction between hydraulic fractures and natural fractures during the fracturing process,the reservoir stimulation is affected,and the injection scheme also has a big impact on the expansion of hydraulic fractures.Clarifying the impact of the injection scheme on the expansion of hydraulic fractures is of great significance for the development of tight sandstone gas.A two-dimensional digital model of the tight sandstone formation in the Yanchang Formation of the Ordos Basin was established based on the extraction of natural fracture data using unmanned aerial vehicle(UAV)photogrammetric technique.The two-dimensional digital model was imported into ABAQUS finite element software,and hydraulic fracturing numerical simulations were carried out under three injection schemes using the method of globally embedding cohesive elements.The results show that the length and height of hydraulic fractures can be increased by using the pulse liquid injection with constant amplitude,the fracture pressure can be reduced by using the pulse liquid injection with variable amplitude,the variation trend of hydraulic fracture propagation pressure is highly consistent with the injection speed,and the failure mode of rock in the process of hydraulic fracture propagation is mainly tensile failure.

关 键 词：水力压裂 cohesive单元 无人机摄影测量 天然裂缝 数值模拟 

分 类 号：TE242[石油与天然气工程—油气井工程]