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 t...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.展开更多
The Mesozoic volcanic rocks of the Bodong Low Uplift in the Bohai Bay Basin have been studied and explored for years.In 2024,the LK7-A well drilled in this region tested high-yield oil and gas flows from volcanic weat...The Mesozoic volcanic rocks of the Bodong Low Uplift in the Bohai Bay Basin have been studied and explored for years.In 2024,the LK7-A well drilled in this region tested high-yield oil and gas flows from volcanic weathered crust.These volcanic rocks need to be further investigated in terms of distribution patterns,conditions for forming high-quality reservoirs,and main factors controlling hydrocarbon accumulation.Based on the logging,geochemical and mineralogical data from wells newly drilled to the Mesozoic volcanic rocks in the basin,and high-resolution 3D seismic data,a comprehensive study was conducted for this area.The research findings are as follows.First,the volcanic rocks in the LK7-A structure are adakites with a large source area depth,and the deep and large faults have provided channels for the emplacement of intermediate-acidic volcanic rocks.Second,volcanic rock reservoirs are mainly distributed in tectonic breccias and intermediate-acidic lavas,and they are dominantly fractured-porous reservoirs,with high-porosity and low-permeability or medium-porosity and low-permeability.Third,the dominant lithologies/lithofacies is the basic condition for forming large-scale volcanic rock reservoirs.Structural fractures and late-stage strong weathering are crucial mechanisms for the formation scale of reservoirs in the Mesozoic volcanic rocks.Fourth,the Bodong Low Uplift exhibits strong hydrocarbon charging by two sags and overpressure mudstone capping,which are favorable for forming high-abundance oil and gas reservoirs.The Mesozoic volcanic buried hills in the study area reflect good trap geometry,providing favorable conditions for large-scale reservoir formation,and also excellent migration and accumulation conditions.Areas with long-term exposure of intermediate-acidic volcanic rocks,particularly in active structural regions,are the key targets for future exploration.展开更多
基金Supported by the Research Project of CNOOC(KJZH-2021-0003-00).
文摘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.
基金Supported by the the National Natural Science Foundation of China(U24B2017)。
文摘The Mesozoic volcanic rocks of the Bodong Low Uplift in the Bohai Bay Basin have been studied and explored for years.In 2024,the LK7-A well drilled in this region tested high-yield oil and gas flows from volcanic weathered crust.These volcanic rocks need to be further investigated in terms of distribution patterns,conditions for forming high-quality reservoirs,and main factors controlling hydrocarbon accumulation.Based on the logging,geochemical and mineralogical data from wells newly drilled to the Mesozoic volcanic rocks in the basin,and high-resolution 3D seismic data,a comprehensive study was conducted for this area.The research findings are as follows.First,the volcanic rocks in the LK7-A structure are adakites with a large source area depth,and the deep and large faults have provided channels for the emplacement of intermediate-acidic volcanic rocks.Second,volcanic rock reservoirs are mainly distributed in tectonic breccias and intermediate-acidic lavas,and they are dominantly fractured-porous reservoirs,with high-porosity and low-permeability or medium-porosity and low-permeability.Third,the dominant lithologies/lithofacies is the basic condition for forming large-scale volcanic rock reservoirs.Structural fractures and late-stage strong weathering are crucial mechanisms for the formation scale of reservoirs in the Mesozoic volcanic rocks.Fourth,the Bodong Low Uplift exhibits strong hydrocarbon charging by two sags and overpressure mudstone capping,which are favorable for forming high-abundance oil and gas reservoirs.The Mesozoic volcanic buried hills in the study area reflect good trap geometry,providing favorable conditions for large-scale reservoir formation,and also excellent migration and accumulation conditions.Areas with long-term exposure of intermediate-acidic volcanic rocks,particularly in active structural regions,are the key targets for future exploration.
