摘要
水力压裂是非常规油气开采的关键技术。在进行水力压裂的过程中,水力裂缝和天然裂隙相互作用形成复杂缝网是非常规油气高效开采的前提,而射孔方案设计对缝网的复杂程度有着重要影响。为了更深入研究压裂缝网的演化机理,模拟真实节理裂隙岩体在水力压裂中的裂缝扩展过程,从而科学、合理地优化射孔方案,本文采用全局嵌入cohesive单元的方法,利用Python进行二次开发创建DFN离散裂隙网络,建立了考虑离散裂隙网络的岩体天然裂隙模型,同时设置相同条件下不考虑DFN离散裂隙网络的模型进行对比,研究不同角度射孔方案对压裂效果的影响。通过MATLAB编程提取加载过程中的声发射定位图和声发射能量数据,对裂纹破裂机理和扩展过程进行了进一步分析。结果表明:天然裂缝的活化受射孔间产生的应力阴影、射孔与天然裂缝的角度影响;查明页岩的天然裂缝分布规律,设法提高射孔与天然裂缝的角度,使水力裂缝更容易与天然裂缝沟通并沿着天然裂缝扩展,从而形成复杂缝网。
Hydraulic fracturing is a key technology for unconventional oil and gas exploration.In the process of hydraulic fracturing,the interaction of hydraulic fractures and natural fractures to form a complex fracture network is the premise for the efficient exploitation of unconventional oil and gas,and the design of perforation scheme has an important impact on the complexity of the fracture network.In order to further study the evolution mechanism of the fracture network,simulate the fracture propagation process of the real jointed fractured rock mass in hydraulic fracturing,and optimize the perforation plan scientifically and reasonably,this paper adopts the method of global embedding of cohesive elements,and uses Python to carry out the second development.A DFN discrete fracture network was created,and a natural fracture model of the rock mass considering the discrete fracture network was established.At the same time,the models without DFN discrete fracture network were set under the same conditions for comparison,and the influence of different angles of perforation schemes on the fracturing effect was studied.The acoustic emission localization map and acoustic emission energy data during the loading process are extracted by MATLAB programming,and the crack rupture mechanism and propagation process are further analyzed.The results show that the activation of natural fractures is affected by the stress shadow generated between perforations and the angle between perforations and natural fractures;the distribution law of natural fractures in shale is identified,and the angle between perforation and natural fractures is improved to make hydraulic fractures easier.It communicates with and spreads along the natural fractures to form a complex fracture network.
作者
赵岩
崔振东
彭瑞东
韩伟歌
张建勇
司凯
赵磊磊
ZHAO Yan;CUI Zhendong;PENG Ruidong;HAN Weige;ZHANG Jianyong;SI Kai;ZHAO Leilei(School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Key Laboratory of Shale Gas and Geoengineering,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Institutions of Earth Science,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;School of Mechanics and Civil Engineering,State Key Laboratory of Coal Resources and Safe Mining,China University of Mining&Technology(Beijing),Beijing 100083,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;College of Geological Engineering,Institute of Disaster Prevention,Sanhe 065201,China;Zhengzhou University of Technology,Zhengzhou 450044,China;Xinjiang Institute of Engineering,School of Mining Engineering and Geology,Urumqi 830023,China)
出处
《工程地质学报》
CSCD
北大核心
2024年第4期1322-1333,共12页
Journal of Engineering Geology
基金
国家自然科学基金专项项目(资助号:42141009)
国家自然科学基金面上项目(资助号:41972296)。
