Eogenetic karst and its control on reservoirs in the Ordovician Majiagou Formation, eastern Sulige gas field, Ordos Basin, NW China

Xie, K., Tan, X., Feng, M., Wang, B., Zhong, S., Yang, M., Nie, W., Qiao, Z. and Zeng, W. (2020) Eogenetic karst and its control on reservoirs in the Ordovician Majiagou Formation, eastern Sulige gas field, Ordos Basin, NW China. Petroleum Exploration and Development, 47(6), pp. 1246-1261. (doi: 10.1016/s1876-3804(20)60133-7)

Abstract

To further ascertain the origin of the Ordovician Majiagou Formation reservoirs in the Ordos Basin, the M54-M51 sub-members of the Ordovician Majiagou Formation in the eastern Sulige gasfield of Ordos Basin were taken as examples to analyze the vertical development characteristics of eogenetic karst and to discover the dissolution mechanism and its control on reservoirs through observation of a large number of cores and thin sections. According to detailed analysis of petrologic characteristics, the reservoir rock types include micritic dolomite, grain dolomite and microbialite which have mainly moldic pore, intergranular (dissolved) pore, and (dissolved) residual framework pore as main reservoir space respectively. The study area developed upward-shallowing sequences, with an exposure surface at the top of a single upward-shallowing sequence. The karst systems under the exposure surface had typical exposure characteristics of early dissolution and filling, indicating these reservoirs were related to the facies-controlled eogenetic karstification. With the increase of karstification intensity, the reservoirs became worse in physical properties.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Xie, Mr Kang
• Authors: Xie, K., Tan, X., Feng, M., Wang, B., Zhong, S., Yang, M., Nie, W., Qiao, Z., and Zeng, W.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Petroleum Exploration and Development
• Publisher: KeAi Communications
• ISSN: 1876-3804
• Copyright Holders: Copyright © 2020, Research Institute of Petroleum Exploration and Development, PetroChina
• First Published: First published in Petroleum Exploration and Development 47(6):1246-1261
• Publisher Policy: Reproduced under a Creative Commons licence