The Songliao Basin, one of the biggest continental petroliferous basins in eastern China, is a Mesozoic- Cenozoic fault-depressed and fault-subsided basin developed on the Hercynian fold basement. Generally, rearrange...The Songliao Basin, one of the biggest continental petroliferous basins in eastern China, is a Mesozoic- Cenozoic fault-depressed and fault-subsided basin developed on the Hercynian fold basement. Generally, rearranged hopanes are considered to be formed by clay- mediated acidic catalysis under oxic or suboxic environment, whereas high abundance of rearranged hopanes were found in hydrocarbon source rocks and crude oils that are derived from salty environment in the Songliao Basin. This phenomenon rarely happens all over the world.展开更多
Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements...Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements in the carbonate cemented zones indicate that:(1)carbonate cements are composed dominantly of ferrocalcite,ferroan dolomite,and ankerite;(2)carbonate cements are formed under a high temperature circumstance in the subsurface,and organic fluid migration has an important effect on the formation of them;and(3)carbon and oxygen ions in the carbonate cements migrate from the underlying overpressured system.This suggests that the occurrence of carbonate cemented zones in this region results from multiple phases of organic fluid expulsion out of the overpressure compartment through geological time.This study provides a plausible mechanism of the formation of carbonate cemented zones adjacent to the top overpressured surface in the clastic sedimentary basins,and has an important implication for understanding the internal correlation between the formation of carbonate cemented zones adjacent to top overpressured surface and geofluids expulsion out of overpressured system.展开更多
Large amounts of data regarding the influence of temperature and pressure on the thermal stability of crude oil have been pub-lished;however,the role of reservoir mediums has received little attention.Experiments invo...Large amounts of data regarding the influence of temperature and pressure on the thermal stability of crude oil have been pub-lished;however,the role of reservoir mediums has received little attention.Experiments involving oil cracking in the presence of montmorillonite,illite,calcite,quartz and water were conducted in closed gold tubes to investigate the effects of these reservoir mediums on oil destruction.This was done by screening variations in the chemical and stable carbon isotopic components of nC10+and gasoline-range hydrocarbons(nC8-)present in various systems.Results indicated that reservoir mediums have an active role in oil cracking under experimental conditions.The concentrations of nC10+in the cracked residues progressively decreased in systems containing oil+water+illite,oil+water+montmorillonite,oil+water,oil+water+quartz and oil+water+calcite.In comparison with the system containing oil+water,our results indicated a retardation effect for oil cracking in systems in the presence of illite and montmorillonite,and an acceleration effect on oil destruction in systems in the presence of calcite and quartz.nC10+became increasingly depleted in 13C in systems with oil+water+illite,oil+water+calcite,oil+water+montmorillonite,oil+water+quartz and oil+water.No obvious correlation was observed between concentrations and stable carbon isotopic components of nC6-nC8 and nC10+in the individual systems.The discrepancies in chemical and stable carbon isotopic components of nC6-nC8 and nC10+in the pyrolyzed residues highlighted the important role of reservoir mediums to control carbon-carbon cleavage of nC10+and then the isomerization,cyclolization and aromatization reactions;as well as governing the occurrence and thermal destruction of nC6-nC8 under experimental conditions.This research may have critical implications in reconstructing chemical kinetic models for natural oil cracking.展开更多
基金supported by the National Natural Science Foundation of China(grant No.41272170)
文摘The Songliao Basin, one of the biggest continental petroliferous basins in eastern China, is a Mesozoic- Cenozoic fault-depressed and fault-subsided basin developed on the Hercynian fold basement. Generally, rearranged hopanes are considered to be formed by clay- mediated acidic catalysis under oxic or suboxic environment, whereas high abundance of rearranged hopanes were found in hydrocarbon source rocks and crude oils that are derived from salty environment in the Songliao Basin. This phenomenon rarely happens all over the world.
基金supported by the Important National Science&Technology Specific Projects(Grant No.2008ZX05001)Scientific Development Projects of Petrochina Company Limited(Grant No.2008B-0100)+2 种基金the Doctoral Education Program Fund of Ministry of Education,China(Grant No.20060491505)American Association of Petroleum Geologists Grants-in-Aid Foundation ProgramNational Natural Science Foundation of China(Grant Nos.40739904,40902039)
文摘Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements in the carbonate cemented zones indicate that:(1)carbonate cements are composed dominantly of ferrocalcite,ferroan dolomite,and ankerite;(2)carbonate cements are formed under a high temperature circumstance in the subsurface,and organic fluid migration has an important effect on the formation of them;and(3)carbon and oxygen ions in the carbonate cements migrate from the underlying overpressured system.This suggests that the occurrence of carbonate cemented zones in this region results from multiple phases of organic fluid expulsion out of the overpressure compartment through geological time.This study provides a plausible mechanism of the formation of carbonate cemented zones adjacent to the top overpressured surface in the clastic sedimentary basins,and has an important implication for understanding the internal correlation between the formation of carbonate cemented zones adjacent to top overpressured surface and geofluids expulsion out of overpressured system.
基金supported by the National Natural Science Foundation of China(40672084)the National Basic Research Program of China(2006CB202303)+1 种基金the Earmarked Fund of the State Key Laboratory of Organic Geochemistry(OGL-200916)the Science Funding of State Key Laboratory of Enhanced Oil Recovery(Research Institute of Petroleum Exploration and Development)
文摘Large amounts of data regarding the influence of temperature and pressure on the thermal stability of crude oil have been pub-lished;however,the role of reservoir mediums has received little attention.Experiments involving oil cracking in the presence of montmorillonite,illite,calcite,quartz and water were conducted in closed gold tubes to investigate the effects of these reservoir mediums on oil destruction.This was done by screening variations in the chemical and stable carbon isotopic components of nC10+and gasoline-range hydrocarbons(nC8-)present in various systems.Results indicated that reservoir mediums have an active role in oil cracking under experimental conditions.The concentrations of nC10+in the cracked residues progressively decreased in systems containing oil+water+illite,oil+water+montmorillonite,oil+water,oil+water+quartz and oil+water+calcite.In comparison with the system containing oil+water,our results indicated a retardation effect for oil cracking in systems in the presence of illite and montmorillonite,and an acceleration effect on oil destruction in systems in the presence of calcite and quartz.nC10+became increasingly depleted in 13C in systems with oil+water+illite,oil+water+calcite,oil+water+montmorillonite,oil+water+quartz and oil+water.No obvious correlation was observed between concentrations and stable carbon isotopic components of nC6-nC8 and nC10+in the individual systems.The discrepancies in chemical and stable carbon isotopic components of nC6-nC8 and nC10+in the pyrolyzed residues highlighted the important role of reservoir mediums to control carbon-carbon cleavage of nC10+and then the isomerization,cyclolization and aromatization reactions;as well as governing the occurrence and thermal destruction of nC6-nC8 under experimental conditions.This research may have critical implications in reconstructing chemical kinetic models for natural oil cracking.
