Differential Characteristics of the Upper Ordovician-Lower Silurian Wufeng-Longmaxi Shale Reservoir and its Implications for Exploration and Development of Shale Gas in/around the Sichuan Basin

论文摘要

The Upper Ordovician Wufeng-Lower Silurian Longmaxi shale is widely distributed in the Sichuan Basin and its periphery, which is the key stratum for marine shale gas exploration and development（E&D） in China. Based on sedimentary environment, material basis, storage space, fracability and reservoir evolution data, the reservoir characteristics of the Wufeng-Longmaxi shale and their significance for shale gas E&D are systematically compared and analyzed in this paper. The results show that（1） the depocenter of the Wufeng（WF）-Longmaxi（LM） shale gradually migrates from east to west. The high-quality shale reservoirs in the eastern Sichuan Basin are mainly siliceous shales, which are primarily distributed in the graptolite shale interval of WF2-LM5. The high-quality reservoirs in the southern Sichuan Basin are mainly calcareous-siliceous and organic-rich argillaceous shales, which are distributed in the graptolite shale interval of WF2-LM7.（2） Deep shale gas（the burial depth >3500 m） in the Sichuan Basin has high-ultrahigh pressure and superior physical properties. The organic-rich siliceous, calcareous-siliceous and organic-rich argillaceous shales have suitable reservoir properties. The marginal area of the Sichuan Basin has a higher degree of pressure relief, which leads to the argillaceous and silty shales evolving into direct cap rocks with poor reservoir/good sealing capacity.（3） Combining shale gas exploration practices and impacts of lithofacies, depth, pressure coefficient and brittle-ductile transition on the reservoir properties, it is concluded that the favorable depth interval of the Wufeng-Longmaxi shale gas is 2200～4000 m under current technical conditions.（4） Aiming at the differential reservoir properties of the Wufeng-Longmaxi shale in the Sichuan Basin and its periphery, several suggestions for future research directions and E&D of shale gas are formulated.

论文目录

• 1 Introduction
• 2 Geological Settings
•   2.1 Regional tectonic background
•   2.2 Sedimentary environment and shale distribution
• 3 Samples and Methods
• 4 Results
•   4.1 Material basis of shale gas generation
•     4.1.1 Organic geochemistry
•     4.1.2 Mineral composition
•   4.2 Storage space and physical properties
•     4.2.1 Organic matter-hosted pores
•     4.2.2 Pore structure
•     4.2.3 Physical properties
•   4.3 Fracability
• 5 Discussions
•   5.1 Differential evolution of reservoirs
•   5.2 Challenges for shale gas exploration and development
• 6 Conclusions

文章来源

类型: 期刊论文

作者: WANG Ruyue,HU Zongquan,LONG Shengxiang,LIU Guangxiang,ZHAO Jianhua,DONG Li,DU Wei,WANG Pengwei,YIN Shuai

来源: Acta Geologica Sinica(English Edition) 2019年03期

年度: 2019

分类: 基础科学,工程科技Ⅰ辑

专业: 地质学,石油天然气工业

单位: SINOPEC Petroleum Exploration and Production Research Institute,SINOPEC Key Laboratory of Shale Gas/Oil Exploration & Production,State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,School of Geosciences, China University of Petroleum (East China),Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Minerals, Shandong University of Science and Technology

基金: granted by the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2017ZX05036002–001),National Natural Science Foundation of China (No. 41202103,41872124),SINOPEC Ministry of Science and Technology Project (Grant No. P17027–2)

分类号: P618.13

页码: 520-535

总页数: 16

文件大小: 1413K

下载量: 51