Multi-scale fractures formation and distribution in tight sandstones—a case study of Triassic Chang 8 Member in the southwestern Ordos Basin

作     者：Gaojian XIAO Ling HU Yang LUO Yujing MENG Ali Bassam Taher AL-SALAFI Haoran LIU Gaojian XIAO;Ling HU;Yang LUO;Yujing MENG;Ali Bassam Taher AL-SALAFI;Haoran LIU

作者机构：Key Laboratory of Tectonics and Petroleum ResourcesChina University of GeosciencesWuhan 430074China Wenhua CollegeWuhan 430074China Faculty of Petroleum and Natural ResourcesSana’a UniversitySana’aYemen Louisiana State UniversityBaton Rouge LA 7080USA 

出 版 物：《Frontiers of Earth Science》 (地球科学前沿（英文版）)

年 卷 期：2022年第16卷第2期

页      面：483-498页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：We thank the financial support from the National Natural Science Foundation of China(Nos.41902147 and 41402117) the China National Science and Technology Major Project(No.2016ZX05048-001-01-CS).We also thank the Sinopec Huabei Company for providing the core samples and the other data sets,and the permission to publish this article 

主　　题：natural fractures characteristics geological significance tight sandstone reservoir Upper Triassic Yanchang Formation 

摘      要：Fracture system is an important factor controlling tight oil accumulation in the Triassic Chang 8 Member,southwestern Ordos Basin,China.A systematic characterization of the multi-scale natural fractures is a basis for the efficient tight oil *** on outcrops,seismic reflections,well cores,well logs(image and conventional logging),casting thin sections,and scanning electron microscope observation,the multi-scale fractures occurrences and their influences on Chang 8 tight sandstone reservoirs are *** results show that three periods of strike-slip faults and four scales of natural fractures developed,namely mega-scale(length7×10^(7) mm),macro-scale(3.5×10^(5)length7×10^(7) mm),meso-scale(10length3.5×10^(5) mm),and micro-scale(length10 mm)*** mega-and macro-scale fractures developed by strike-slip faults are characterized by strike-segmentation and lateral zonation,which connect the source and *** scale fractures also influence the distribution and effectiveness of traps and reservoirs,which directly influence the hydrocarbon charging and *** meso fractures include the tectonic,diagenetic,as well as hydrocarbon generation-related overpressure *** meso-and micro-scale fractures improve the sandstone physical properties and also the tight oil well production *** integrated study helps to understand the distribution of multi-scale fractures in tight sandstones and provides a referable case and workflow for multi-scale fracture evaluation.