About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

AAPG Bulletin, V. 105, No. 2 (February 2021), P. 275-307.

Copyright ©2021. The American Association of Petroleum Geologists. All rights reserved.

DOI: 10.1306/07202017327

Origin and charging histories of diagenetic traps in the Junggar Basin

Jianguo Pan,1 Guodong Wang,2 Yongqiang Qu,3 Wen Qi,4 Lu Yin,5 Duonian Xu,6 Tuanyu Teng,7 Bin Wang,8 Kaijun Tan,9 and Linjun Huang10

1Key Laboratory of Reservoir Characterization, PetroChina, Lanzhou, Gansu, China; Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
2Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
3Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
4Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
5Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
6Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
7Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
8Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
9Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]
10Research Institute of Petroleum Exploration & Development–Northwest, PetroChina, Lanzhou, Gansu, China; [email protected]

ABSTRACT

Oil and gas accumulations in the sandy conglomerate diagenetic traps that developed in the fan delta of the Triassic Baikouquan Formation of the Mahu sag, Junggar Basin, differ from stratigraphic accumulations controlled by sedimentary facies. This study uses conventional gas chromatography–mass spectrometry measurements, mineralogical and petrological data, fluid inclusion analyses, and geophysical inversion to confirm the trap type and accumulation processes. The results indicate that accumulations in the sandy conglomerate formed in distributary channels of the fan-delta front, with the boundary controlled by reservoir quality. In turn, reservoir quality was controlled by differential diagenesis caused by detrital-feldspar content, paleotemperature, and formation fluids, suggesting that the trap is a diagenetic trap. The diagenetic trap formed from secondary pores developed in the fan-delta front facies with seals forming through a combination of altered sandy beds and mudstone. The critical physical property of the reservoir, based on the ratio of its average capillary radius to the ratio of its seal, is a crucial parameter for describing diagenetic trap boundaries. Here, it effectively distinguishes between reservoirs at different burial depths. A good correlation exists between the formation of the diagenetic traps and hydrocarbon filling. Three hydrocarbon charging and two accumulation stages are identified. The diagenetic traps primarily formed in the Jurassic, and the last charging stage of highly mature oil charge occurred in the Early Cretaceous. Few studies have investigated the conglomerate diagenetic trap studied herein, so this study should improve the understanding of oil and gas traps.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].