Microscopic characterization and formation mechanisms of deep-water sandy-debris-flow and turbidity-current sandstones in a lacustrine basin： a case study in the Yanchang Formation of the Ordos Basin, China

作     者：Jian-Bo Liao Ai-Hua Xi Zhi-Yong Li Hua-Qing Liu Xiang-Bo Li Rong Wanyan 

作者机构：School of Geoscience and Technology Southwest Petroleum University Chengdu 610500 Sichuan China Petro China Research Institute of Petroleum Exploration &Development-Northwest Lanzhou 730020 Gansu China Key Laboratory of Reservoir Description CNPCLanzhou 730020 Gansu China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2018年第15卷第1期

页      面：28-40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：funded by the Natural Science Foundation of China(41772099) the National Science and Technology Major Project(2017ZX05001-003) 

主　　题：Sandy debris flow Turbidite Ordos Basin Petrology Reservoir properties 

摘      要：Deep-water deposition is a current issue in sedimentological research. Sandy-debris-flow sandstones and turbidity-current sandstones are the main types of sandstone that are the focus of considerable disputes in this research. Previous studies mainly focused on description of the macroscopic sedimentary structure and theoretical derivation of the formation mechanisms. The microscopic petrological characteristics, reservoir properties, and formation mechanisms of deep-water sandy-debris-flow and turbidity-current sandstones have been studied in the Yanchang Formation of the Ordos Basin,China, by means of field outcrop surveys, thin-section identification, geochemical element analysis, and porosity and permeability measurements under overburden pressure. The content of detrital grains in the sandy-debris-flow sandstones is high, whereas the contents of mica sheets and matrix are low. The fine-grained matrix is distributed unevenly within the pores. A considerable number of residual intergranular pores are preserved in the middle of single sand bodies, resulting in relatively better reservoir properties. The total number of detrital grains in the turbidite sandstone is low, while it contains abundant mica sheets and matrix. The mica sheets and fine-grained matrix are distributed evenly within the pores, resulting in serious damage to pores and poor reservoir properties. The sandy-debris-flow sandstones in the center of the lake basin form a high-quality reservoir; thus, this area is suitable for oil and gas exploration.