Prediction of natural fracture in shale oil reservoir based on R/S analysis and conventional logs

作     者：Haoran XU Wei JU Xiaobing NIU Shengbin FENG Yuan YOU Hui YANG Sijia LIU Wenbo LUAN Haoran XU;Wei JU;Xiaobing NIU;Shengbin FENG;Yuan YOU;Hui YANG;Sijia LIU;Wenbo LUAN

作者机构：Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process(Ministry of Education)China University of Mining and TechnologyXuzhou 221008China School of Resources and GeosciencesChina University of Mining and TechnologyXuzhou 221116China School of GeosciencesChina University of Petroleum(East China)Qingdao 266580China Institute of Exploration and DevelopmentPetroChina Changqing Oilfield CompanyXi'an 710018China School of Computer Science and TechnologyChina University of Mining and TechnologyXuzhou 221116China 

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

年 卷 期：2021年第15卷第3期

页      面：705-718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：supports are from the National Natural Science Foundation of China(Grant Nos.41702130,41971335) Natural Science Foundation of Jiangsu Province,China(BK20201349) Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD) 

主　　题：natural fracture prediction shale oil reservoir R/S analysis Chang 7 oil-bearing layer Ordos Basin 

摘      要：Investigation into natural fractures is extremely important for the exploration and development of low-permeability *** studies have proven that abundant oil resources are present in the Upper Triassic Yanchang Formation Chang 7 oil-bearing layer of the Ordos Basin,which are accumulated in typical low-permeability shale *** fractures are important storage spaces and flow pathways for shale *** this study,characteristics of natural fractures in the Chang 7 oil-bearing layer are first *** results indicate that most fractures are shear fractures in the Heshui region,which are characterized by high-angle,unfilled,and ENE-WSW-trending ***,natural fracture distributions in the Yanchang Formation Chang 7 oil-bearing layer of the study area are predicted based on the R/S analysis *** of AC,CAL,ILD,LL8,and DEN are selected and used for fracture prediction in this study,and the R(n)/S(n)curves of each log are *** quadratic derivatives are calculated to identify the concave points in the R(n)/S(n)curve,indicating the location where natural fracture *** the difference in sensitivity of each log to natural fracture,gray prediction analysis is used to construct a new parameter,fracture prediction indicator K,to quantitatively predict fracture *** addition,fracture development among different wells is *** results show that parameter K responds well to fracture *** minor errors may probably be caused by the heterogeneity of the reservoir,limitation of core range and fracture size,dip angle,filling minerals,etc.