Currently,limited studies of immiscible water-alternating-CO_(2)(imWACO_(2))flooding focus on the impact of reservoir heterogeneity on reservoir development outcomes.Given this,using the heterogeneous reservoirs in th...Currently,limited studies of immiscible water-alternating-CO_(2)(imWACO_(2))flooding focus on the impact of reservoir heterogeneity on reservoir development outcomes.Given this,using the heterogeneous reservoirs in the Gao 89-1 block as a case study,this study conducted slab core flooding experiments and numerical simulations to assess the impact of reservoir heterogeneity on imWACO_(2)flooding efficiency.It can be concluded that imWACO_(2)flooding can enhance the sweep volume and oil recovery compared to continuous CO_(2)flooding.As the permeability difference increases,the difference in the swept volume between zones/layers with relatively high and low permeability increases.To optimize the exploitation of reservoirs in the Gao 89-1 block,the optimal timing and CO_(2)injection rate for imWACO_(2)flooding are determined at water cut of 40%and 10000 m^(3)/d,respectively.A short injection-production semi-period,combined with multiple cycles of water and CO_(2)injection alternations,is beneficial for enhanced oil recovery from imWACO_(2)flooding.展开更多
The Penglai 9-1 oilfield is the largest granite buried-hill oilfield in China presently,genesis and evolution of the granite buried-hill reservoir is complex.Based on geochemical,geophysical,experimental simulation an...The Penglai 9-1 oilfield is the largest granite buried-hill oilfield in China presently,genesis and evolution of the granite buried-hill reservoir is complex.Based on geochemical,geophysical,experimental simulation and other methods,and combined with field geological observation,genetic mechanism of the granite buried-hill reservoir of the Penglai 9-1 oilfield and its hydrocarbon accumulation mode were well investigated.Results showed that the granite was formed by magmatic intrusion along deep faults under intraplate breakup of North China Plate,it was the product of magmatic activities of Yanshan tectonic episode of Circum-Pacific Tectonic Region,and the intrusion time was 160e170 Ma of the Jurassic.Formation of the granite buried-hill reservoir was mainly controlled by the epigenic karstification and tectonic reconstruction,the Yanshanian weathering and denudation controlled macroscopic development characteristics of the granite buried-hill reservoir,and faults and joints formed by Cenozoic tectonic movement promoted modification of the granite buried-hill reservoir.Laterally,thickness of the granite buried-hill reservoir had a positive correlation with fracture density.Vertically,the granite rocks could be divided into five zones:soil zone,sandy zone,broken zone,fracture zone and base rock zone.The upper-middle part(sandy zone,broken zone,fracture zone)of the granite buried hill was the highquality favorable reservoir zone and the main oil-bearing interval.展开更多
基金funded by the National Natural Science Foundation of China(No.51974343)the Open Fund of Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas(Yangtze University)(No.YQZC202307)+2 种基金the Qingdao Postdoctoral Applied Research Project(No.qdyy20200084)the China Postdoctoral Science Foundation(No.2021M703588)a project of Science&Technology R&D Department of SINOPEC entitled Key Technology for Optimization Design of 3D Development of Shale oil in Dongying Sag(No.P23026).
文摘Currently,limited studies of immiscible water-alternating-CO_(2)(imWACO_(2))flooding focus on the impact of reservoir heterogeneity on reservoir development outcomes.Given this,using the heterogeneous reservoirs in the Gao 89-1 block as a case study,this study conducted slab core flooding experiments and numerical simulations to assess the impact of reservoir heterogeneity on imWACO_(2)flooding efficiency.It can be concluded that imWACO_(2)flooding can enhance the sweep volume and oil recovery compared to continuous CO_(2)flooding.As the permeability difference increases,the difference in the swept volume between zones/layers with relatively high and low permeability increases.To optimize the exploitation of reservoirs in the Gao 89-1 block,the optimal timing and CO_(2)injection rate for imWACO_(2)flooding are determined at water cut of 40%and 10000 m^(3)/d,respectively.A short injection-production semi-period,combined with multiple cycles of water and CO_(2)injection alternations,is beneficial for enhanced oil recovery from imWACO_(2)flooding.
基金supported by the National Science and Technology Major Project of China(No.2016ZX05024-003).
文摘The Penglai 9-1 oilfield is the largest granite buried-hill oilfield in China presently,genesis and evolution of the granite buried-hill reservoir is complex.Based on geochemical,geophysical,experimental simulation and other methods,and combined with field geological observation,genetic mechanism of the granite buried-hill reservoir of the Penglai 9-1 oilfield and its hydrocarbon accumulation mode were well investigated.Results showed that the granite was formed by magmatic intrusion along deep faults under intraplate breakup of North China Plate,it was the product of magmatic activities of Yanshan tectonic episode of Circum-Pacific Tectonic Region,and the intrusion time was 160e170 Ma of the Jurassic.Formation of the granite buried-hill reservoir was mainly controlled by the epigenic karstification and tectonic reconstruction,the Yanshanian weathering and denudation controlled macroscopic development characteristics of the granite buried-hill reservoir,and faults and joints formed by Cenozoic tectonic movement promoted modification of the granite buried-hill reservoir.Laterally,thickness of the granite buried-hill reservoir had a positive correlation with fracture density.Vertically,the granite rocks could be divided into five zones:soil zone,sandy zone,broken zone,fracture zone and base rock zone.The upper-middle part(sandy zone,broken zone,fracture zone)of the granite buried hill was the highquality favorable reservoir zone and the main oil-bearing interval.
