Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,com...Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,complex oil-water contact within and faint responses of the oil zone,which causes the lower accuracy of reservoir fluid property identification with conventional mudlogging and wirelogging techniques.Applying the geochemical logging,fluorescent logging,mud logging and cutting logging technology,in combination with formation test data,this paper distinguishes the crude oil types,analyzes the logging response characteristics of oil zone after water washing,and establishes the interpretation charts and parameter standards for reservoir fluid properties.The crude oil can be divided into two types,namely viscous-heavy and thin-light,based on total hydrocarbon content and component concentration tested by mud logging,features of pyrolysis gas chromatogram and fluorescence spectroscopy.The general characteristics of oil layers experienced water washing include the decrease of total hydrocarbon content and component concentration from mud logging,the decrease of S1 and PS values from geochemical logging,the decrease of hydrocarbon abundance and absence of some light components in pyrolysis gas chromatogram,and the decrease of fluorescence area and intensity from fluorescence logging.According to crude oil types,the cross plots of S1 versus peak-baseline ratio,and the cross plots of rock wettability versus fluorescence area ratio are drawn and used to interpret reservoir fluid property.Meanwhile,the standards of reservoir fluid parameter are established combining with the parameters of PS and the parameters in above charts,and comprehensive multiparameter correlation in both vertical and horizontal ways is also performed to interpret reservoir fluid property.The application in the Doseo Basin achieved great success,improving interpretation ability of fluid property in the reservoir with complex oil-water contact,and also provided technical reference for the efficient exploration and development of similar reservoirs.展开更多
Crude oil samples taken from the southern part of western Qaidam Basin were analyzed with GC/MS in order to understand the geochemical characteristics of crude oils.The results reveal that most crude oils are characte...Crude oil samples taken from the southern part of western Qaidam Basin were analyzed with GC/MS in order to understand the geochemical characteristics of crude oils.The results reveal that most crude oils are characterized by high abundance of gammacerane and C35 homohopane,which are the representative characteristics of saline lacustrine crude oils.Based on the variation of the ratios of gammacerane/C30 hopane(G/H) and C35 homoho-pane/C34 homohopane(C35/C34H),two crude oil groups,A and B,are identified.Group-A crude oils mainly occurr in the north of the study area,with higher ratios of G/H(>0.8) and C35/C34H(>1.2),whereas group-B crude oils,selected from the south of the study area,show lower ratios of G/H(<0.8) and C35/C34H(<1.0).In addition,group-A crude oils are distinguished into three subgroups in accordance with their different ratios of G/H and C35/C34H and different distribution characteristics of n-alkanes,isoprenoids and steranes.These may be helpful for understanding the distribution characteristics of crude oils in the southern part of western Qaidam Basin and providing clues to the forthcoming exploration of crude oils and gas.展开更多
The Linnan subsag is the main oil producer of the Linpan oil zone. Based on the oil group composition,gas chromatography data and biomarker analysis,it was indicated that crude oils from different oilfields varied gre...The Linnan subsag is the main oil producer of the Linpan oil zone. Based on the oil group composition,gas chromatography data and biomarker analysis,it was indicated that crude oils from different oilfields varied greatly in group composition and showed obvious heterogeneities in the aspects of precursor type,crude oil maturity and hydrocarbon depositional environment. According to the characteristics of source rocks,three oil populations can be distinguished,i.e.,the southern,northern and transitional oil populations. Furthermore,on the basis of post-reservoir reworking processes,the medium conditions of hydrocarbon-generating environment and differences in maturity,six oil families and twelve sub-families were distinquished. An integrated study suggested that the fac-tors leading to such heterogeneities in crude oil composition mainly include different source rocks,multi-stage oil/gas charging,geo-chromatographic effects during oil/gas migration,reservoir heterogeneities and various post-reservoir secondary alterations.展开更多
Carbazole_type compounds were analyzed using GC and GC_MS_MS. A relatively high concentration of carbazole_type compounds was detected in crude oils of different types (marine and non_marine) and different maturities ...Carbazole_type compounds were analyzed using GC and GC_MS_MS. A relatively high concentration of carbazole_type compounds was detected in crude oils of different types (marine and non_marine) and different maturities (low mature and mature) in Tarim, Liaohe and Keilu basins. The results suggest the ratios of 1, 8-dimethyl-/2, 7-dimethylcarbazole and benzo carbazole/benzo carbazole might be taken as petroleum migration parameters.展开更多
基金funded by a project entitled exploration field evaluation and target optimization of key basins in Chad and Niger(No.2019D-4308)initiated by the scientific research and technology development project of china national petroleum corporation.
文摘Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,complex oil-water contact within and faint responses of the oil zone,which causes the lower accuracy of reservoir fluid property identification with conventional mudlogging and wirelogging techniques.Applying the geochemical logging,fluorescent logging,mud logging and cutting logging technology,in combination with formation test data,this paper distinguishes the crude oil types,analyzes the logging response characteristics of oil zone after water washing,and establishes the interpretation charts and parameter standards for reservoir fluid properties.The crude oil can be divided into two types,namely viscous-heavy and thin-light,based on total hydrocarbon content and component concentration tested by mud logging,features of pyrolysis gas chromatogram and fluorescence spectroscopy.The general characteristics of oil layers experienced water washing include the decrease of total hydrocarbon content and component concentration from mud logging,the decrease of S1 and PS values from geochemical logging,the decrease of hydrocarbon abundance and absence of some light components in pyrolysis gas chromatogram,and the decrease of fluorescence area and intensity from fluorescence logging.According to crude oil types,the cross plots of S1 versus peak-baseline ratio,and the cross plots of rock wettability versus fluorescence area ratio are drawn and used to interpret reservoir fluid property.Meanwhile,the standards of reservoir fluid parameter are established combining with the parameters of PS and the parameters in above charts,and comprehensive multiparameter correlation in both vertical and horizontal ways is also performed to interpret reservoir fluid property.The application in the Doseo Basin achieved great success,improving interpretation ability of fluid property in the reservoir with complex oil-water contact,and also provided technical reference for the efficient exploration and development of similar reservoirs.
文摘Crude oil samples taken from the southern part of western Qaidam Basin were analyzed with GC/MS in order to understand the geochemical characteristics of crude oils.The results reveal that most crude oils are characterized by high abundance of gammacerane and C35 homohopane,which are the representative characteristics of saline lacustrine crude oils.Based on the variation of the ratios of gammacerane/C30 hopane(G/H) and C35 homoho-pane/C34 homohopane(C35/C34H),two crude oil groups,A and B,are identified.Group-A crude oils mainly occurr in the north of the study area,with higher ratios of G/H(>0.8) and C35/C34H(>1.2),whereas group-B crude oils,selected from the south of the study area,show lower ratios of G/H(<0.8) and C35/C34H(<1.0).In addition,group-A crude oils are distinguished into three subgroups in accordance with their different ratios of G/H and C35/C34H and different distribution characteristics of n-alkanes,isoprenoids and steranes.These may be helpful for understanding the distribution characteristics of crude oils in the southern part of western Qaidam Basin and providing clues to the forthcoming exploration of crude oils and gas.
基金This project was financially supported by the National Natural Science Foundation of China (Grant No. 40502013)
文摘The Linnan subsag is the main oil producer of the Linpan oil zone. Based on the oil group composition,gas chromatography data and biomarker analysis,it was indicated that crude oils from different oilfields varied greatly in group composition and showed obvious heterogeneities in the aspects of precursor type,crude oil maturity and hydrocarbon depositional environment. According to the characteristics of source rocks,three oil populations can be distinguished,i.e.,the southern,northern and transitional oil populations. Furthermore,on the basis of post-reservoir reworking processes,the medium conditions of hydrocarbon-generating environment and differences in maturity,six oil families and twelve sub-families were distinquished. An integrated study suggested that the fac-tors leading to such heterogeneities in crude oil composition mainly include different source rocks,multi-stage oil/gas charging,geo-chromatographic effects during oil/gas migration,reservoir heterogeneities and various post-reservoir secondary alterations.
文摘Carbazole_type compounds were analyzed using GC and GC_MS_MS. A relatively high concentration of carbazole_type compounds was detected in crude oils of different types (marine and non_marine) and different maturities (low mature and mature) in Tarim, Liaohe and Keilu basins. The results suggest the ratios of 1, 8-dimethyl-/2, 7-dimethylcarbazole and benzo carbazole/benzo carbazole might be taken as petroleum migration parameters.
