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

Kang XIE; Xiucheng TAN; Min FENG; Baobao WANG; Shoukang ZHONG; Mengying YANG; Wancai NIE; Zhanfeng QIAO; Wei ZENG

Petroleum Exploration and Development (Dec 2020)

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

Kang XIE,
Xiucheng TAN,
Min FENG,
Baobao WANG,
Shoukang ZHONG,
Mengying YANG,
Wancai NIE,
Zhanfeng QIAO,
Wei ZENG

Affiliations

Kang XIE: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; Department of Key Laboratory of Carbonate Reservoir of CNPC, Southwest Petroleum University, Chengdu 610500, China
Xiucheng TAN: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; Department of Key Laboratory of Carbonate Reservoir of CNPC, Southwest Petroleum University, Chengdu 610500, China; Corresponding author
Min FENG: Exploration and Development Research Institute of PetroChina Changqing Oilfield Company, Xi'an 710018, China
Baobao WANG: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; Department of Key Laboratory of Carbonate Reservoir of CNPC, Southwest Petroleum University, Chengdu 610500, China
Shoukang ZHONG: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; Department of Key Laboratory of Carbonate Reservoir of CNPC, Southwest Petroleum University, Chengdu 610500, China
Mengying YANG: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; Department of Key Laboratory of Carbonate Reservoir of CNPC, Southwest Petroleum University, Chengdu 610500, China
Wancai NIE: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; Yihuang Natural Gas Department of PetroChina Changqing Oilfield Company, Xi'an 710018, China
Zhanfeng QIAO: PetroChina Hangzhou Research Institute of Geology, Hangzhou 310023, China
Wei ZENG: Department of Key Laboratory of Carbonate Reservoir of CNPC, Southwest Petroleum University, Chengdu 610500, China

Journal volume & issue: Vol. 47, no. 6
pp. 1246 – 1261

Abstract

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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.

Published in Petroleum Exploration and Development

ISSN: 2096-4803 (Print); 1876-3804 (Online)
Publisher: KeAi Communications Co., Ltd.
Country of publisher: China
LCC subjects: Technology: Chemical technology: Oils, fats, and waxes: Petroleum refining. Petroleum products
Website: https://www.keaipublishing.com/en/journals/petroleum-exploration-and-development/

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