Key controlling factors and enrichment mechanisms of tight reservoirs in 6th member of Triassic Yanchang Formation, Chaishangyuan area, southeastern Ordos Basin

• Published in: Shi you shi yan di zhi Vol. 44; no. 2; pp. 251 - 261
• Main Authors: Zhuo WANG, Jingzhou ZHAO, Xuangang MENG, Shihu ZHAO, Zhenzhen SHEN, Heng ZHANG, Feilong GAO
• Format: Journal Article
• Language: Chinese
• Published: Editorial Office of Petroleum Geology and Experiment 01.03.2022
• Subjects: chaishangyuan area; chang 6 reservoir; enrichment rule; main controlling factor; ordos basin
• ISSN: 1001-6112
• DOI: 10.11781/sysydz202202251

Chaishangyuan area locates in the Qilicun Oilfield of the southeastern Ordos Basin, the first onshore oil field discovered in China, and its main layer for oil-producing is the 6th member of Triassic Yanchang Formation (Chang 6). At present, the comprehensive study on the key controlling factors of Chang 6 tight oil reservoir in this area is not clear. In this paper, a large number of drilling, logging, core, production test and other data, combined with laboratory experimental observation were carried out to progress the understanding of the factors controlling reservoir formation. In addition, the concepts of the ratio of underlying sand thickness to formation thickness and the ratio of overlying mud thickness to formation thickness were introduced to comprehensively analyze the forming characteristics of Chang 6 reservoir in the study area and the controlling effects of source rocks, reservoirs, structures, caprocks and migration conditions on Chang 6 tight reservoirs. The Chang 6 tight reservoir in the st