摘要
压裂实践表明,页岩储层的水力裂缝呈现出非平面、多分支的复杂延伸模式,这与传统压裂理论认为的对称平面双翼裂缝从形成机理上存在本质的区别。基于室内实验、矿场压裂实践、理论分析和数值模拟等研究成果,系统分析了页岩储层压裂缝成网延伸的受控因素。研究表明:页岩储层的裂缝延伸形态受到地质因素和工程因素的双重作用,从储层地质属性上看,岩石的脆性矿物含量越高、岩石的力学弹性特征越强、水平应力差越小以及天然裂缝越发育,越有利于压裂缝的成网延伸与扩展;从压裂作业的工程条件上来说,施工净压力越高、压裂液流体黏度越低以及压裂规模越大,越有利于形成充分扩展的缝网。该研究对认识页岩储层缝网扩展机理以及提高页岩储层压裂设计的科学性具有重要的理论价值和现实意义。
Fracturing practice shows that hydraulic fractures in shale reservoir present complex extending models of non-planar and multiple branches, which is essentially different from traditional symmetry plane hi-wing fractures in forming mechanism. Based on the research results of indoor experiments, field fracturing practice, theory analysis and numerical simulation etc, this paper has systematically analyzed the controlling factors of hydraulic fractures extending into network in shale formations. Research shows the extending shape of fractures in shale reservoir is influenced by both geological factors and engineering factors： according to reservoir geological attributes, higher brittle mineral contents of rock, stronger elastic characteristic of rock mechanical properties, smaller horizontal differential stress and better developed natural fractures will be constructive to better extension and propagation for hydraulic fractures extending into network; according to engineering conditions of fracturing operations, higher operation net pressure, lower fluid viscosity and larger fracturing scale will be more helpful to the formation of fully propagated fracture-network. This study has important theoretical value and practical significance to the understanding of shale reservoir fracture-network propagation mechanism and can improve the science of shale reservoir fracturing design.
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2013年第1期1-9,共9页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
国家科技重大专项(2011ZX05014)
中海油"十二五"重大专项"海上低渗油藏有效开发模式
方法与适用技术研究"
中央财政支持地方高校发展专项资金"石油与天然气工程国家一级学科"
关键词
页岩
缝网
脆性矿物
天然裂缝
净压力
shale
fracture-network
brittle mineral
natural fractures
net pressure
