摘要
疏松砂岩水力压裂裂缝的典型特征是大量分支缝、微裂缝和一定钝度的裂缝尖端及剪切带的形成等.主要通过对相关文献的调研,分析了剪切作用、拉伸作用等对裂缝形态特征(起裂、转向、延伸)等力学行为所产生的影响,通过针对一些疏松砂岩的压裂实验研究发现,其滤失过程主要受到缝尖区域的影响,而且滤失一般发生在裂缝扩展之前.裂缝缝尖周围的局部应力往往是影响裂缝起裂和裂缝开度的主导参数,裂缝的形态特征则是应力、渗透率、流态等综合作用的结果,对疏松砂岩裂缝形态特征的形成做了进一步的解释.
The typical features of hydraulic fracturing of unconsolidated sands are the large number of branch fractures and micro cracks,and a certain dullness of crack tips and some shear zones. This paper analyzes the influence of the tensile shear on the fracture morphology （initiation, reorientation and dilatation）. Some experimental study of hydraulic fracturing of the unconsolidated sands indicates that the filtration process is mainly affected by the fracture tip area, and the filtration commonly occurs before the crack propagation. The confining stress around the fracture tip is often the leading parameters to influence the fracture initiation and the crack opening, and the crack characteristics are integrated effects of the stress, the permeability and the flow state, which explains the hydraulic fracture characteristics.
出处
《力学与实践》
北大核心
2014年第4期396-402,共7页
Mechanics in Engineering
关键词
疏松砂岩
水力压裂
剪切作用
裂缝
unconsolidated sands, hydraulic fracturing, shear action, fracture
