内蒙古西部沙漠砂支撑力学性能及压裂工程意义  

Holding Mechanical Properties of Desert Sand and Significance of Fracturing Engineering in Western Inner Mongolia

作　　者：陈立超 张典坤 吕帅锋 肖宇航 王生维[3] CHEN Lichao;ZHANG Diankun;LYU Shuaifeng;XIAO Yuhang;WANG Shengwei(School of Resources and Environmental Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;State Key Laboratory of Coal and CBM Co-mining,Jincheng 048012,Shanxi,China;School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]内蒙古工业大学资源与环境工程学院,呼和浩特010051 [2]煤与煤层气共采全国重点实验室,山西晋城048012 [3]中国地质大学(武汉)资源学院,武汉430074 [4]中国石油勘探开发研究院,北京100083

出　　处：《材料导报》2024年第S02期137-143,共7页Materials Reports

基　　金：内蒙古自治区重点研发和成果转化计划项目(2023YFSH0005);内蒙古自治区自然科学基金项目(2023MS05018);中央引导地方科技发展资金项目(23ZYQA319)。

摘　　要：深层非常规油气压裂裂缝开度小,闭合应力高,资源效益开发对石英砂颗粒的支撑表现提出了更高要求。为摸清强压缩荷载下砂颗粒形变破碎和承载性能演化规律以及主控因素,本工作针对内蒙古西部腾格里、乌兰布和、库布齐沙漠砂,利用自制加载装置对砂颗粒开展压缩实验,得到加载载荷-位移关系特征,据此分析砂颗粒压缩下的变形破碎规律及支撑表现的演化特征。结果表明:(1)腾格里、乌兰布和、库布齐沙漠砂压缩下位移-载荷曲线包括机械压实阶段、孔隙压缩阶段及弹性变形阶段,三个阶段分别对应砂颗粒的离散状态、点接触状态和面接触状态,随着颗粒接触面积增大其承载能力快速提升;(2)砂颗粒的压实阶段划分及承载能力主要受颗粒粒径和颗粒边界形态的控制,颗粒粒径越小、颗粒边界棱角剧烈,颗粒承载能力更强,其压缩中机械压实阶段和孔隙压缩阶段更短;(3)压缩下细粒砂以矿物面接触形式为主,矿物间接触面积大,力链发育且链长短,协调外部荷载能力强,削弱应力集中,降低砂颗粒破碎率,提升颗粒整体支撑表现,适宜作为深层压裂裂缝充填支撑材料;(4)本工作提出了一种综合颗粒粒径、颗粒边界棱角发育程度的支撑剂评价指标体系,认为圆球度低的棱角发育砂颗粒通过卯榫效应增强整体性,深层裂缝支撑能力更强。In order to reveal the evolution law of deformation breaking and bearing performance of sand under compression load and the controlling factors,in this paper,forthe sand of Tengger,Ulan Buhe and Kubuqi deserts in western Inner Mongolia,compression tests were carried out on sand,and the load-displacement relationship were obtained,the deformation law of sand under compression and the evolution of proppant performance were analyzed.The results showed that:(1)the displacement-load curves of Tengger,Ulan Buhe and Kubuqi desert sand includes three stages:mechanical compaction stage,pore compression stage and elastic deformation stage,the bearing capacity of sand increases rapidly with the increase of fines contact area.(2)the compaction stage division and bearing capacity of sand are mainly controlled by particles size and morphology.The smaller particle size and the sharper grain boundary edges are,the stronger the bearing capacity of sand is,and the mechanical compaction stage and pore compression stage are shorter.(3)Under compression,fine sand is mainly in the form of mineral contact,the contact area between minerals is large,the force chains is developed and the chain length is long,the external load coordination ability is strong,the stress concentration is weakened,the sand breakage rate is reduced,the support performance is improved,and the fine sand is suitable for filling materials for deep hydraulic fractures.(4)It is concluded that the angle-developed sand with low sphericity can enhance the integrity,and the support ability of deep fractures is stronger.

关 键 词：深层压裂裂缝 砂颗粒 压缩作用 颗粒粒度 颗粒形态 支撑表现 内蒙古西部沙漠 

分 类 号：TE32[石油与天然气工程—油气田开发工程] TU45[建筑科学—岩土工程]