Comparative analyses of petroleum generation potential,reservoir volume,frackability,and oil mobility were conducted on 102 shale cores from the Dongpu Depression.Results show the shale has high organic matter content...Comparative analyses of petroleum generation potential,reservoir volume,frackability,and oil mobility were conducted on 102 shale cores from the Dongpu Depression.Results show the shale has high organic matter contents composed of oil-prone type I and type II kerogens within the oil window.Various types of pores and fractures exist in the shale,with a porosity of up to 14.9%.The shale has high brittle mineral contents,extensive fractures,and high potential for oil mobility due to high seepage capacity and overpressure.Although the petroleum generation potential of the shale at Well PS18-8 is relatively greater than that at Well PS18-1,oil content of the latter is greater due to the greater TOC.The porosity and fracture density observed in Well PS18-1 are greater and more conducive to shale oil enrichment.Although the shales in Wells PS18-1 and PS18-8 have similar brittle mineral contents,the former is more favorable for anthropogenic fracturing due to a higher preexisting fracture density.Besides,the shale at Well PS18-1 has a higher seepage capacity and overpressure and therefore a higher oil mobility.The fracture density and overpressure play key roles in shale oil enrichment.展开更多
The pore structure and oil content of shales have an important influence on the oil mobility and enrichment.In this study,the lacustrine shale samples from the Qingshankou Formation(Q1)of Songliao Basin were selected....The pore structure and oil content of shales have an important influence on the oil mobility and enrichment.In this study,the lacustrine shale samples from the Qingshankou Formation(Q1)of Songliao Basin were selected.TOC,pyrolysis,XRD and nitrogen adsorption were performed on the original and extracted shale samples.Then the influence of mineral composition and organic matter(OM)on the development of nano-scale pore,the oil phase states and mobility were analyzed.The Q1 shale samples can be sub-divided into three types according to the isotherm characteristics.Type A samples are characterized by high kerogen content,with oil mainly existing in the free phase state.Type B samples are characterized by medium kerogen content,oil mainly exists in the absorbed phase state.Type C samples are characterized by low kerogen content,with trace oil found in the absorbed phase state.Nano-scale organic pores are well developed in the Q1 Formation.Oil is primarily found in the pore spaces with diameters less than 10 nm,this being the pore size threshold for mobile shale oil.When TOC>2.0 wt%and EOM>1.0 wt%,Q1 Formation shale oil mobility is high,resulting in prospective drilling targets.展开更多
The EOR techniques are employed to recover more oil from mature reservoirs after the primary and secondary oil production stages.Polymer flooding as a chemical EOR method involves adding polymer molecules in order to ...The EOR techniques are employed to recover more oil from mature reservoirs after the primary and secondary oil production stages.Polymer flooding as a chemical EOR method involves adding polymer molecules in order to increase water viscosity.Increasing water viscosity will improve the mobility ratio of injected fluid to reservoir fluid toward a more favorable value.Therefore,vertical and areal sweep efficiencies are increased compared to typical water flooding.Polymer flooding will be most effective if applied in the early stages of a water flood while the mobile oil saturation is still high.Polymer is also a critical component when considering other chemical EOR technologies such as alkaline-polymer or alkaline-surfactant-polymer.The present study covers two main parts.In the first part,fundamental of polymer flooding as it related to experimental work and simulation are discussed.The challenge of polymer flooding applications in high temperature and high salinity(HTHS)environment is also discussed in this part.In the second part,the synergy of polymer with surfactant and alkaline as chemical enhancing oil recovery(CEOR)methods is discussed.展开更多
基金This study was fnancially supported by the China Postdoctoral Science Foundation(2019M660054)Science Foundation of China University of Petroleum(Beijing)(2462019BJRC005)+3 种基金Strategic Cooperation Technology Projects of CNPC and CUPB(ZLZX2020-01-05)Natural Science Foundation of China(41872148,41872128)NSFC Basic Research Program on Deep Petroleum Resource Accumulation and Key Engineering Technologies(U19B6003-02)the Science Projects of the Sinopec Zhongyuan Oilfeld Company(P15022).
文摘Comparative analyses of petroleum generation potential,reservoir volume,frackability,and oil mobility were conducted on 102 shale cores from the Dongpu Depression.Results show the shale has high organic matter contents composed of oil-prone type I and type II kerogens within the oil window.Various types of pores and fractures exist in the shale,with a porosity of up to 14.9%.The shale has high brittle mineral contents,extensive fractures,and high potential for oil mobility due to high seepage capacity and overpressure.Although the petroleum generation potential of the shale at Well PS18-8 is relatively greater than that at Well PS18-1,oil content of the latter is greater due to the greater TOC.The porosity and fracture density observed in Well PS18-1 are greater and more conducive to shale oil enrichment.Although the shales in Wells PS18-1 and PS18-8 have similar brittle mineral contents,the former is more favorable for anthropogenic fracturing due to a higher preexisting fracture density.Besides,the shale at Well PS18-1 has a higher seepage capacity and overpressure and therefore a higher oil mobility.The fracture density and overpressure play key roles in shale oil enrichment.
基金financially supported by the National Natural Science Foundation of China(No.41972156)the Science and Technology Project of Heilongjiang Province(No.2020ZX05A01)
文摘The pore structure and oil content of shales have an important influence on the oil mobility and enrichment.In this study,the lacustrine shale samples from the Qingshankou Formation(Q1)of Songliao Basin were selected.TOC,pyrolysis,XRD and nitrogen adsorption were performed on the original and extracted shale samples.Then the influence of mineral composition and organic matter(OM)on the development of nano-scale pore,the oil phase states and mobility were analyzed.The Q1 shale samples can be sub-divided into three types according to the isotherm characteristics.Type A samples are characterized by high kerogen content,with oil mainly existing in the free phase state.Type B samples are characterized by medium kerogen content,oil mainly exists in the absorbed phase state.Type C samples are characterized by low kerogen content,with trace oil found in the absorbed phase state.Nano-scale organic pores are well developed in the Q1 Formation.Oil is primarily found in the pore spaces with diameters less than 10 nm,this being the pore size threshold for mobile shale oil.When TOC>2.0 wt%and EOM>1.0 wt%,Q1 Formation shale oil mobility is high,resulting in prospective drilling targets.
文摘The EOR techniques are employed to recover more oil from mature reservoirs after the primary and secondary oil production stages.Polymer flooding as a chemical EOR method involves adding polymer molecules in order to increase water viscosity.Increasing water viscosity will improve the mobility ratio of injected fluid to reservoir fluid toward a more favorable value.Therefore,vertical and areal sweep efficiencies are increased compared to typical water flooding.Polymer flooding will be most effective if applied in the early stages of a water flood while the mobile oil saturation is still high.Polymer is also a critical component when considering other chemical EOR technologies such as alkaline-polymer or alkaline-surfactant-polymer.The present study covers two main parts.In the first part,fundamental of polymer flooding as it related to experimental work and simulation are discussed.The challenge of polymer flooding applications in high temperature and high salinity(HTHS)environment is also discussed in this part.In the second part,the synergy of polymer with surfactant and alkaline as chemical enhancing oil recovery(CEOR)methods is discussed.
