低压洗井对微裂隙剪切滑移的诱导规律  

Induction Mechanism of Micro-Fracture Shear-Slip by Well Cleanout

作　　者：刘庆 柯柏林 林天懿 杨淼[1] 赵连海[1] 黄璐 熊馨 LIU Qing;KE Bolin;LIN Tianyi;YANG Miao;ZHAO Lianhai;HUANG Lu;XIONG Xin(Beijing Institute of Geothermal Engineering,Beijing 102218)

机构地区：[1]北京市地热研究院,北京102218

出　　处：《城市地质》2018年第3期27-33,共7页Urban Geology

基　　金：北京市科技计划(2161100004516016)

摘　　要：针对低泵压条件下地热储层洗井作业对近井地带天然裂缝的诱导作用开展研究,完善了流体作用下天然裂缝发生剪切滑移的条件。基于最大周向应力准则,在同时考虑Ⅰ,Ⅱ型断裂复合扩展,水岩化学作用,流体对岩石强度的影响作用,以及流体对缝面摩擦系数的影响等因素的作用下,建立了应力强度因子计算公式。提出了流体作用下缝面的摩擦修正系数,以及实验测定摩擦修正系数,水岩化学损伤系数的方法。分别讨论了渗透压、摩擦纠正系数、水岩作用对应力强度因子的影响规律。得出了在流体作用下,微裂隙发生剪切滑移的数学模型,并结合具体施工情况提出了施工建议。To aim at the construction purpose to fully activate natural fractures under low pump-pressure in geothermal reservoirs,the condition of shear-slip of natural cracks under the action of fluid is established.Based on the maximum circumferential stress criterion,the formula of stress intensity factor is established by considering the I,II compound fracture extension,water-rock interaction,fluid effect of rock strength,and the fluid influence to friction factors on the cementation plane.A new conception of the correction friction coefficient is proposed.The method to get correction coefficient of friction,and water-rock damage coefficient by experiment is introduced.The influence law of osmotic pressure,correction friction coefficient,water-rock effect to stress intensity factor is discussed respectively.The mathematic model of shear-slip in micro-fissure under the effect of fluid was obtained,and the construction suggestions were put forward according to the specific construction conditions.

关 键 词：剪切滑移 微裂隙 摩擦系数 应力强度因子 流体作用 

分 类 号：TU452[建筑科学—岩土工程]