Enrichment mechanisms and accumulation model of ultra-deep water and ultra-shallow gas:A case study of Lingshui 36-1 gas field in Qiongdongnan Basin,South China Sea  

作　　者：XU Changgui WU Keqiang PEI Jianxiang HU Lin 

机构地区：[1]China National Offshore Oil Corporation,Beijing 100010,China [2]National Engineering Research Center of Offshore Oil and Gas Exploration,Beijing 100010,China [3]Hainan Branch,CNOOC Limited,Haikou 570312,China

出　　处：《Petroleum Exploration and Development》2025年第1期50-63,共14页石油勘探与开发(英文版)

基　　金：Supported by the Research Project of CNOOC(KJZH-2021-0003-00).

摘　　要：Based on petroleum exploration and new progress of oil and gas geology study in the Qiongdongnan Basin,combined with seismic,logging,drilling,core,sidewall coring,geochemistry data,a systematic study is conducted on the source,reservoir-cap conditions,trap types,migration and accumulation characteristics,enrichment mechanisms,and reservoir formation models of ultra-deep water and ultra-shallow natural gas,taking the Lingshui 36-1 gas field as an example.(1)The genetic types of the ultra-deep water and ultra-shallow natural gas in the Qiongdongnan Basin include thermogenic gas and biogenic gas,and dominated by thermogenic gas.(2)The reservoirs are mainly composed of the Quaternary deep-water submarine fan sandstone.(3)The types of cap rocks include deep-sea mudstone,mass transport deposits mudstone,and hydrate-bearing formations.(4)The types of traps are mainly lithological,and also include structural-lithological traps.(5)The migration channels include vertical transport channels such as faults,gas chimneys,fracture zones,and lateral transport layers such as large sand bodies and unconformity surfaces,forming a single or composite transport framework.A new natural gas accumulation model is proposed for ultra-deep water and ultra-shallow layers,that is,dual source hydrocarbon supply,gas chimney and submarine fan composite migration,deep-sea mudstone-mass transport deposits mudstone-hydrate-bearing strata ternary sealing,late dynamic accumulation,and large-scale enrichment at ridges.The new understanding obtained from the research has reference and enlightening significance for the next step of deepwater and ultra-shallow layers,as well as oil and gas exploration in related fields or regions.

关 键 词：South China Sea Qiongdongnan Basin ultra-deep water ultra-shallow layer natural gas gas hydrate QUATERNARY gravity flow submarine fan accumulation model 

分 类 号：P61[天文地球—矿床学]