摘要
水力压裂作为油气高效开发的关键技术,水力裂缝形态监测对油气田开发具有重要意义。考虑到目前LF-DAS光纤应变率信号响应模式多样,解释难度大,对传统PKN模型进行扩展,并结合固体弹性变形理论,建立了基于半解析-有限元方法的光纤应变率信号正演模型。基于该模型模拟了单簇裂缝扩展过程中水平邻井及垂直邻井光纤应变率信号响应,模拟结果与现场实际光纤数据基本一致;研究了监测距离及监测井井斜角对光纤应变率信号的影响。分析结果发现:当井斜角增大时,应变率瀑布图中的“蓝-红-蓝”条带会产生倾斜变形;应变率瀑布图中的“蓝-红-蓝”条带具有显著放大效应,随监测距离的增加,条带宽度不断变宽;监测距离对光纤应变率信号强度影响大,信号强度随监测距离呈幂函数递减。研究结果可为后续邻井LF-DAS光纤应变率信号解释水力裂缝形态、指导监测井井位布置提供理论依据。
Hydraulic fracturing is a key technology for efficient oil and gas development,and the monitoring of hydraulic fracture morphology is of great significance to the development of oil and gas fields.Considering that the response modes of LF-DAS fiber strain rate signal are diverse and difficult to interpret,this paper extended the traditional PKN model,and combined the theory of solid elastic deformation to build a forward model of fiber strain rate signal based on semi-analytical–finite element method.Using this model,the fiber strain rate signal responses of horizontal and vertical adjacent wells in the process of single-cluster fracture propagation were simulated,indicating the results basically consistent with the actual fiber data.Then,the influences of monitoring distance and monitoring well deviation angle on fiber strain rate signal were identified.The analysis results show that as the deviation angle increases,the“blue-red-blue”strip in the strain rate waterfall diagram tilts and deforms.The"blue-red-blue"strip has a significant application effect,and the strip width becomes wider with the increase of the monitoring distance.The monitoring distance has a great influence on the fiber strain rate signal strength which decreases with the monitoring distance in a power function.The research results provide a theoretical basis for using the LF-DAS fiber strain rate signal of adjacent wells to interpret the hydraulic fracture morphology and guide the geometric arrangement of monitoring wells.
作者
郝亚龙
陈勉
韦世明
王琪琪
隋微波
张宇
Hao Yalong;Chen Mian;Wei Shiming;Wang Qiqi;Sui Weibo;Zhang Yu(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing);MOE Key Laboratory of Petroleum Engineering,China University of Petroleum(Beijing);Oil&Gas Technology Research Institute of PetroChina Changqing Oilfield Company)
出处
《石油机械》
北大核心
2025年第8期100-108,共9页
China Petroleum Machinery
基金
国家自然科学基金重点项目“提高超深大斜度井压裂效率的关键力学问题研究”(52334001)。
关键词
水力压裂
裂缝监测
LF-DAS
光纤解释
监测距离
应变率
正演模型
hydraulic fracturing
fracture monitoring
LF-DAS
optical fiber interpretation
monitoring distance
strain rate
forward model
