摘要
利用页岩体内部天然裂缝劈裂形成粗糙导流岩板,测试了页岩气藏清水压裂网络裂缝的导流能力,重点研究了裂缝剪切错位对页岩裂缝导流能力的影响.实验结果表明,不同支撑形式裂缝的导流能力差异显著,裂缝中缺少支撑剂时,需要形成剪切错位才能提供足够的导流能力,否则非支撑裂缝导流能力不足以利用复杂裂缝网络.非支撑裂缝导流能力至少在2个数量级内变化,主要受错位程度、粗糙度、岩石力学性质等影响.粗糙度较大的剪切裂缝更易形成高导流能力,但导流能力与粗糙度并没有绝对相关性,粗糙度对裂缝导流能力仅在低闭合应力条件下影响显著.低硬度页岩的剪切裂缝导流能力可比高硬度页岩低一个数量级以上.
The flow guiding rock plate is obtained by splitting a natural fracture in the shale,and using the split rock plate simulating a fracture,the flow guiding capacity of the fracture in the shale gas reservoir is tested under clear water fracturing.The effect of the fracture shear dislocation on the flow guiding capacity is investigated.Experimental results demonstrate that the flow guiding capacity of the fracture with different propped cases is significantly different.When there is no sufficient proppant in the fracture,a shear dislocation is needed in order to obtain sufficient flow guiding capacity,and otherwise,the fracture can not utilize the flow guiding capacity of complicated fracture network.The flow guiding capacity of the fracture varies at least within two orders of magnitude,and it is influenced mainly by the dislocation amount,the roughness of the fracture surfaces,the mechanic property of the shale,etc.The shear fracture with large roughness generally has great flow guiding capacity,but there is no absolute correlation between the roughness and the flow guiding capacity.The roughness has obvious effect on the flow guiding capacity only under low closure stress.The flow guiding capacity of the shear fracture in low hardness shale is less one order of magnitude than that in high hardness shale.
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2013年第4期69-72,77,共5页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
国家重大科技专项"3000型成套压裂装备研制及应用示范工程"(编号:2011ZX05048)
关键词
页岩气藏
剪切裂缝
导流能力
裂缝网络
粗糙度
shale gas reservoir
shear fracture
flow guiding capacity
fracture network
roughness
