Geological characteristics and development potential of transitional shale gas in the east margin of the Ordos Basin,NW China

• 作者: DONG Dazhong GUO Wen HE Wenyuan KUANG Lichun LI Shuxin LI Yong LIAO Xinwei QIU Zhen SHI Zhensheng SUN Shasha WEN Shengming WU Jin ZHANG Leifu ZHANG Surong
• 来源期刊: 石油勘探与开发:英文版
• 学科: 地球科学
• 关键词: shale gas marine-nonmarine transitional shale favorable area collaborative production Permian Shanxi Formation Ordos Basin
• 年，卷（期）: 2020,（3）
• 页码范围: 471-482
• 页数: 12页
• 分类号: P618.13

摘要

The shales in the 2nd Member of Shanxi formation in the east margin of the Ordos Basin were deposited in a marine-nonmarine transitional environment during the Permian.Based on the recent breakthroughs in the shale gas exploration and theoretical understandings on the shale gas of the study area,with a comparison to marine shale gas in the Sichuan Basin and marine-nonmarine transitional shale gas in the U.S.,this study presents the geological characteristics and development potential of marine-nonmarine transitional gas in the study area.Four geological features are identified in the 2nd Member of the Shanxi Formation in the study area has:(1)stable sedimentary environment is conductive to deposition of widely distributed organic shale;(2)well-developed micro-and nanoscale pore and fracture systems,providing good storage capacity;(3)high content of brittle minerals such as quartz,leading to effectively reservoir fracturing;and(4)moderate reservoir pressure and relatively high gas content,allowing efficient development of shale gas.The 2nd Member of Shanxi Formation in the east margin of Ordos Basin is rich in shale gas resource.Three favorable zones,Yulin-Linxian,Shiloubei-Daning-Jixian,and Hancheng-Huangling are developed,with a total area of 1.28×104 km2 and resources between 1.8×1012 and 2.9×1012m3,indicating a huge exploration potential.Tests of the 2nd Member of Shanxi Formation in vertical wells show that the favorable intervals have stable gas production and high reserves controlled by single well,good recoverability and fracability.This shale interval has sufficient energy,stable production capacity,and good development prospects,as evidenced by systematic well testing.The east margin of the Ordos Basin has several shale intervals in the Shanxi and Taiyuan formations,and several coal seams interbedded,so collaborative production of different types of natural gas in different intervals can be considered.The study results can provide reference for shale gas exploration and development and promote the rap