中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Origin of a giant fuzzy reflection zone and its implication for natural gas exploration in the southwestern Qiongdongnan Basin of the South China Sea

文献类型:CNKI期刊论文

作者Junhui YU; Pin YAN; Yanlin WANG; Yan QIU; Guanghong TU; Changliang CHEN
发表日期2023-03-15
出处Journal of Oceanology and Limnology
关键词southwestern Qiongdongnan Basin fuzzy reflection zone low velocity gas charging natural gas potential
英文摘要The southwestern depression of the Qiongdongnan Basin(QDNB) hosts thick Cenozoic sediments and awaits major hydrocarbon discovery. Multichannel seismic(MCS) profile CFT2011 across the southwestern QDNB reveals a ~60-km-wide fuzzy reflection zone(FRZ) within the sediments, but its origin and distribution remain unclear. Here ocean bottom seismometer(OBS) data of Line CFT2011 are processed with focus on the velocity structures by traveltime tomography inversion and analyzed together with the coincident and adjacent MCS profiles. The OBS velocity results show that the giant FRZ features lower velocity with difference up to 1.5 km/s and smaller vertical velocity gradient than the surrounding sedimentary sequences at the same depth, likely resulting from enhanced fluid infilling. The MCS profile exhibits that the giant FRZ is about 3–9-km thick and extends from the Paleogene strata rich in organic matters upward to the lower Pleistocene sediments. Within the shallow overlying sediments, multiple bright spots with reverse polarity are imaged and their reflection amplitudes increase with offset,consistent with the features of gas-charged sediments. They are probably shallow gas reservoirs with gases sourced from the deep FRZ. Therefore, the FRZ is proposed to be a giant gas-charged zone, which probably contains lots of hydrocarbon gases migrated vertically from the deep Paleogene source rocks through the boundary faults of the depressions and the minor fractures generated under overpressure. This FRZ is also imaged on the adjacent MCS profiles MCS-L1 and MCS-L2 with the width of about 40 km and 68 km, respectively. It is roughly estimated to cover an area of ~1 900 km2 and host a volume of ~11 400 km3 assuming an average thickness of 6 km, implying huge natural gas potential in the sedimentary depression of the southwestern QDNB of the South China Sea.
文献子类CNKI期刊论文
资助机构Supported by the Guangdong Basic and Applied Basic Research Foundation (Nos. 2022A1515011836, 2021A1515110851) ; the Science and Technology Planning Project of Guangzhou (No. 202201010230) ; the Special Support Program for Cultivating High-Level Talents in Guangdong Province (No. 2019BT02H594) ; the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)(No. GML2019ZD0104) ; the Open Fund of Key Laboratory of Marine Geology and Environment ; Chinese Academy of Sciences (CAS)(No. MGE2020KG01) ; the National Natural Science Foundation of China (Nos. U1901217, 91855101, 41876052, 42076218) ; Dr. Junhui YU is funded by the Special Research Assistant Funding Program of CAS
v.41期:02页:310-328
语种英文;
分类号P618.13
ISSN号2096-5508
源URL[http://ir.qdio.ac.cn/handle/337002/187173]  
专题中国科学院海洋研究所
作者单位1.KeyLaboratoryofOceanandMarginalSeaGeology,SouthChinaSeaInstituteofOceanology,InnovationAcademyofSouthChinaSeaEcologyandEnvironmentalEngineering,ChineseAcademyofSciences
2.SouthernMarineScienceandEngineeringGuangdongLaboratory(Guangzhou)
3.KeyLaboratoryofMarineGeologyandEnvironment,InstituteofOceanology,ChineseAcademyofSciences
4.KeyLaboratoryofMarineMineralResources,GuangzhouMarineGeologicalSurvey,ChinaGeologicalSurvey,MinistryofNaturalResources
5.UniversityofChineseAcademyofSciences
推荐引用方式
GB/T 7714
Junhui YU,Pin YAN,Yanlin WANG,et al. Origin of a giant fuzzy reflection zone and its implication for natural gas exploration in the southwestern Qiongdongnan Basin of the South China Sea. 2023.

入库方式: OAI收割

来源:海洋研究所

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