裂缝交叉角度对缝网导流能力的影响:以“卜”形结构为例  

Influence of the Fracture Intersection Angle on Conductivity ofFracture Network:A Case Study of “卜” Type Structure

作　　者：刘加杰 宁文祥 王鹏 车永新 何柏 LIU Jia-jie;NING Wen-xiang;WANG Peng;CHE Yong-xin;HE Bo(Sichuan Institute of Nonmetallic(Salt Industry)Geological Survey,Zigong 643021,China;Institute of New Energy and Low-Carbon Technology,Sichuan University,Chengdu 610207,China;Engineering Research Center of Alternative Energy Materials&Devices,Ministry of Education,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川省非金属(盐业)地质调查研究所,自贡643021 [2]四川大学新能源与低碳技术研究院,成都610207 [3]四川大学后续能源材料与器件教育部工程研究中心,成都610065

出　　处：《科学技术与工程》2023年第36期15465-15472,共8页Science Technology and Engineering

基　　金：国家自然科学基金(11872258);四川省科技计划项目重点研发项目(2022YFS0447)。

摘　　要：为了探讨缝网导流能力,将“卜”形交叉裂缝结构视为构成裂缝网络的基本单元。采用外圆内方的橡胶套筒导流室,开展主/次生裂缝交叉角度分别为30°、60°、90°、120°和150°的页岩岩板导流能力试验,并利用裂缝体积等效理论计算交叉裂缝导流能力。试验结果表明:无论次生裂缝与主裂缝的交叉角度如何,相同条件下,次生裂缝总是能提高裂缝网络的导流能力,且提高次生裂缝支撑剂铺置浓度,有利于裂缝网络在高闭合应力中保持稳定、高效的导流能力;然而,流体汇流角度越大,其碰撞等作用造成的流体能量损失也越大,表现为“卜”形裂缝导流能力随交叉角度增大而减小,因此,充分考虑流体汇流时的交叉角度对于准确评价裂缝网络导流能力具有重要意义。Regarding the cross fracture structure of“卜”type as the basic unit of the fracture network to discuss the fracture network conductivity.The conductivity of shale slabs with the intersection angles of primary and secondary fracture of 30°,60°,90°,120°and 150°were carried out,using a rubber sleeve with the outer circle and the inner square configuration as fracture conductivity chamber.And the fracture volume equivalent theory was used to calculate the network conductivity.The experimental results show that the secondary fracture contribute a lot to improve the fracture network conductivity regardless of the intersection angles of primary and secondary fracture and the concentration of proppant placement in the secondary fracture.And increasing the proppant placement concentration is beneficial to maintain in the fracture network conductivity stable and efficient under high closure stress.However,the larger the fluid confluence angle is,the greater the fluid energy loss caused by the fluid collision and other effects,which shows that the“卜”type fracture network conductivity decreases with the increasing the intersection angles of primary and secondary fracture.Therefore,fully considering the intersection angle of the fluid confluence has a significantly important role in accurately evaluating the fracture network conductivity.

关 键 词：导流能力 “卜”形结构 交叉角度 裂缝网络 铺置浓度 

分 类 号：TE377[石油与天然气工程—油气田开发工程]