Based on the production curves,changes in hydrocarbon composition and quantities over time,and production systems from key trial production wells in lacustrine shale oil areas in China,fine fraction cutting experiment...Based on the production curves,changes in hydrocarbon composition and quantities over time,and production systems from key trial production wells in lacustrine shale oil areas in China,fine fraction cutting experiments and molecular dynamics numerical simulations were conducted to investigate the effects of changes in shale oil composition on macroscopic fluidity.The concept of“component flow”for shale oil was proposed,and the formation mechanism and conditions of component flow were discussed.The research reveals findings in four aspects.First,a miscible state of light,medium and heavy hydrocarbons form within micropores/nanopores of underground shale according to similarity and intermiscibility principles,which make components with poor fluidity suspended as molecular aggregates in light and medium hydrocarbon solvents,such as heavy hydrocarbons,thereby decreasing shale oil viscosity and enhancing fluidity and outflows.Second,small-molecule aromatic hydrocarbons act as carriers for component flow,and the higher the content of gaseous and light hydrocarbons,the more conducive it is to inhibit the formation of larger aggregates of heavy components such as resin and asphalt,thus increasing their plastic deformation ability and bringing about better component flow efficiency.Third,higher formation temperatures reduce the viscosity of heavy hydrocarbon components,such as wax,thereby improving their fluidity.Fourth,preservation conditions,formation energy,and production system play important roles in controlling the content of light hydrocarbon components,outflow rate,and forming stable“component flow”,which are crucial factors for the optimal compatibility and maximum flow rate of multi-component hydrocarbons in shale oil.The component flow of underground shale oil is significant for improving single-well production and the cumulative ultimate recovery of shale oil.展开更多
As an insufficiently utilized energy resource,oil shale is conducive to the formation of characteristic microbial communities due to its special geological origins.However,little is known about fungal diversity in oil...As an insufficiently utilized energy resource,oil shale is conducive to the formation of characteristic microbial communities due to its special geological origins.However,little is known about fungal diversity in oil shale.Polymerase chain reaction cloning was used to construct the fungal ribosomal deoxyribonucleic acid internal transcribed spacer（r DNA ITS）clone libraries of Huadian Mine in Jilin Province,Maoming Mine in Guangdong Province,and Fushun Mine in Liaoning Province.Pure culture and molecular identification were applied for the isolation of cultivable fungi in fresh oil shale of each mine.Results of clone libraries indicated that each mine had over 50% Ascomycota（58.4%–98.9%）and 1.1%–13.5%unidentified fungi.Fushun Mine and Huadian Mine had 5.9% and 28.1% Basidiomycota,respectively.Huadian Mine showed the highest fungal diversity,followed by Fushun Mine and Maoming Mine.Jaccard indexes showed that the similarities between any two of three fungal communities at the genus level were very low,indicating that fungi in each mine developed independently during the long geological adaptation and formed a community composition fitting the environment.In the fresh oil-shale samples of the three mines,cultivable fungal phyla were consistent with the results of clone libraries.Fifteen genera and several unidentified fungi were identified as Ascomycota and Basidiomycota using pure culture.Penicillium was the only genus found in all three mines.These findings contributed to gaining a clear understanding of current fungal resources in major oil-shale mines in China and provided useful information for relevant studies on isolation of indigenous fungi carrying functional genes from oil shale.展开更多
基金Supported by the National Natural Science Foundation of China(U22B6004)Scientific Research and Technological Development Project of RIPED(2022yjcq03)Technology Research Project of PetroChina Changqing Oilfield Company(KJZX2023-01)。
文摘Based on the production curves,changes in hydrocarbon composition and quantities over time,and production systems from key trial production wells in lacustrine shale oil areas in China,fine fraction cutting experiments and molecular dynamics numerical simulations were conducted to investigate the effects of changes in shale oil composition on macroscopic fluidity.The concept of“component flow”for shale oil was proposed,and the formation mechanism and conditions of component flow were discussed.The research reveals findings in four aspects.First,a miscible state of light,medium and heavy hydrocarbons form within micropores/nanopores of underground shale according to similarity and intermiscibility principles,which make components with poor fluidity suspended as molecular aggregates in light and medium hydrocarbon solvents,such as heavy hydrocarbons,thereby decreasing shale oil viscosity and enhancing fluidity and outflows.Second,small-molecule aromatic hydrocarbons act as carriers for component flow,and the higher the content of gaseous and light hydrocarbons,the more conducive it is to inhibit the formation of larger aggregates of heavy components such as resin and asphalt,thus increasing their plastic deformation ability and bringing about better component flow efficiency.Third,higher formation temperatures reduce the viscosity of heavy hydrocarbon components,such as wax,thereby improving their fluidity.Fourth,preservation conditions,formation energy,and production system play important roles in controlling the content of light hydrocarbon components,outflow rate,and forming stable“component flow”,which are crucial factors for the optimal compatibility and maximum flow rate of multi-component hydrocarbons in shale oil.The component flow of underground shale oil is significant for improving single-well production and the cumulative ultimate recovery of shale oil.
基金supported by the National Natural Science Foundation of China(No.51204055)the Fundamental Research Funds for the Central Universities(No.N130420002)the China Postdoctoral Science Foundation(20100481205)
文摘As an insufficiently utilized energy resource,oil shale is conducive to the formation of characteristic microbial communities due to its special geological origins.However,little is known about fungal diversity in oil shale.Polymerase chain reaction cloning was used to construct the fungal ribosomal deoxyribonucleic acid internal transcribed spacer（r DNA ITS）clone libraries of Huadian Mine in Jilin Province,Maoming Mine in Guangdong Province,and Fushun Mine in Liaoning Province.Pure culture and molecular identification were applied for the isolation of cultivable fungi in fresh oil shale of each mine.Results of clone libraries indicated that each mine had over 50% Ascomycota（58.4%–98.9%）and 1.1%–13.5%unidentified fungi.Fushun Mine and Huadian Mine had 5.9% and 28.1% Basidiomycota,respectively.Huadian Mine showed the highest fungal diversity,followed by Fushun Mine and Maoming Mine.Jaccard indexes showed that the similarities between any two of three fungal communities at the genus level were very low,indicating that fungi in each mine developed independently during the long geological adaptation and formed a community composition fitting the environment.In the fresh oil-shale samples of the three mines,cultivable fungal phyla were consistent with the results of clone libraries.Fifteen genera and several unidentified fungi were identified as Ascomycota and Basidiomycota using pure culture.Penicillium was the only genus found in all three mines.These findings contributed to gaining a clear understanding of current fungal resources in major oil-shale mines in China and provided useful information for relevant studies on isolation of indigenous fungi carrying functional genes from oil shale.
