摘要
为了对水力压裂裂缝高度进行准确预测,针对高应力多分层的复杂地层,基于断裂力学理论分析裂缝扩展过程中裂缝尖端应力集中产生的塑性区分布对缝高扩展的影响,建立水力压裂缝高计算模型并进行求解,通过与其他2种缝高模型(MFEH、FracPro)计算结果进行对比以验证该模型的准确性。模型实例计算的敏感性分析表明:水力压裂的缝高会呈现阶梯生长的扩展形态,且裂缝缝高越大,阶梯生长的现象越明显;地应力对裂缝缝高的生长起主要的控制作用,地层岩石断裂韧性只在一定程度上对缝高生长有抑制作用;压裂液密度的增大有利于裂缝下尖端的扩展。
To predict fracture height in hydraulic fracturing,we developed and solved a hydraulic fracture height mathematical model aiming at high stress and multi-layered complex formations based on studying the effect of plastic region generated by stress concentration at fracture tip on the growth of fracture height.Moreover,we compared the results from this model with results from two other fracture height prediction models(MFEH,FracPro)to verify the accuracy of the model.Sensitivity analysis by case computation of the model shows that the hydraulic fracture growth in ladder pattern,and the larger the fracture height,the more obvious the ladder growth pattern is.Fracture height growth is mainly influenced by the in-situ stresses.Fracture toughness of rock can prohibit the growth of fracture height to some extent.Moreover,the increase of fracturing fluid density can facilitate the propagation of the lower fracture tip.
作者
李玉伟
龙敏
汤继周
陈勉
付晓飞
LI Yuwei;LONG Min;TANG Jizhou;CHEN Mian;FU Xiaofei(School of Petroleum Engineering,Northeast Petroleum University,Daqing 163318,China;School of Engineering and Applied Sciences,Harvard University,Cambridge 02138,USA;School of Petroleum Engineering,China University of Petroleum,Beijing 102249,China)
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2020年第1期175-185,共11页
Petroleum Exploration and Development
基金
黑龙江省优秀青年科学基金项目“煤层二氧化碳泡沫压裂模型与模拟研究”（YQ2019E007）
关键词
水力压裂
裂缝高度
裂尖塑性区
断裂韧性
高应力多分层地层
hydraulic fracturing
fracture height
plastic region at fracture tip
fracture toughness
multi-layered formation with high in-situ stresses
