Gas hydrate accumulation conditions in the Huaguang Depression of Qiongdongnan Basin and prediction of favorable zones

LIU Jie; YANG Rui; ZHANG Jinghua; WEI Wei; WU Daidai

doi:10.16562/j.cnki.0256-1492.2018072701

Marine Geology & Quaternary Geology > 2019 > 39(1): 134-142. > DOI: 10.16562/j.cnki.0256-1492.2018072701

LIU Jie, YANG Rui, ZHANG Jinghua, WEI Wei, WU Daidai. Gas hydrate accumulation conditions in the Huaguang Depression of Qiongdongnan Basin and prediction of favorable zones[J]. Marine Geology & Quaternary Geology, 2019, 39(1): 134-142. DOI: 10.16562/j.cnki.0256-1492.2018072701

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Gas hydrate accumulation conditions in the Huaguang Depression of Qiongdongnan Basin and prediction of favorable zones

1.
Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Guangzhou 510640, China
2.
Institution of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510640, China
3.
Qingdao Institute of Marine Geology, Qingdao 266071, China
4.
Research Institute of Petroleum Exploration and Development- Langfang, Langfang 065007, China

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Received Date: July 26, 2018
Revised Date: August 15, 2018

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Abstract

Abstract

The temperature and pressure conditions of the shallow deposits in the Huaguang Depression meet well the requirements for natural gas hydrate accumulation. There the maximum thickness of the biogenic methane hydrate stable zone is about 320m, while the maximum thickness of the thermogenic gas hydrate stable zone is about 345m. Gas source rocks occur mainly in the rifting-stage sequence in the western part of the Huaguang Depression, in which there are two stages of hydrocarbon generation, with the later one dominating. It is favorable for the thermogenic natural gas to accumulate in the hydrate stability zone. Since Late Miocene, the rapid deposition of mudstone provided sufficient organic matters for the formation of biogenic gas. Mud diapirs, associated faults and polygonal faults constitute the main fluid migration system for natural gas hydrate accumulation. The western area close to the fault No. 1 is a favorable exploration target. The rapid subsidence since Late Miocene made the Oligocene hydrocarbon source rocks possible to produce a large amount of natural gas, and the overpressure formed by undercompaction provided a powerful driving force for the migration of gas bearing fluid. Thus the thermogenic and biogenic natural gas migrated upwards along mud diapirs and polygon faults to the hydrate stable zone, and eventually formed gas hydrate deposits there. The deep water turbidite channel is doubtlessly a favorable target for exploration of highly saturated hydrate.
- gas hydrate,
- fluid transport,
- turbidite channel,
- Huaguang Depression,
- Qiongdongnan Basin

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References (34)

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Gas hydrate accumulation conditions in the Huaguang Depression of Qiongdongnan Basin and prediction of favorable zones