About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

AAPG Bulletin, V. 109, No. 1 (January 2025), P. 85-98.

Copyright ©2025. The American Association of Petroleum Geologists. All rights reserved.

DOI: 10.1306/10222424020

Hydraulic fracture networks bypassing thick sealing sequences as fluid conduits in deep overpressured strata

Qingfeng Meng,1 Baibing Yang,2 Zhifeng Guo,3 and Fang Hao4

1National Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, China; School of Geosciences, China University of Petroleum (East China), Qingdao, China; [email protected]
2National Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, China; School of Geosciences, China University of Petroleum (East China), Qingdao, China; [email protected]
3National Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, China; School of Geosciences, China University of Petroleum (East China), Qingdao, China; [email protected]
4National Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, China; School of Geosciences, China University of Petroleum (East China), Qingdao, China; [email protected]

ABSTRACT

We used new ocean-bottom-node seismic data to obtain high-resolution images of a gas-bearing structure that holds one of China’s largest offshore gas reservoirs in the South China Sea. This structure, Dongfang 1-1, comprises clustered high-angle fractures in Miocene source rock intervals, with minimal disruption to stratigraphic layering. Seismic reflections within the structure are continuous without indicators of massive mud intrusion into the overlying sediments; therefore, a mud diapir model is unlikely to be applicable. We interpret that this structure formed from coalescing hydraulic fractures during upward propagation, driven by fluid overpressure from natural gas generation. These fracture networks serve as highly efficient pathways for gas-bearing fluids to bypass the 660-m-thick sealing sequences and accumulate in the Pliocene structural trap. Our results provide new insights into the formation mechanism of the Dongfang 1-1 structure and an exciting opportunity for further exploration of subsurface fluid migration in deep overpressured strata.

Pay-Per-View Purchase Options

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

Watermarked PDF Document: $16
Open PDF Document: $28

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].