Petroleum geochemistry contributes to exploration successes by providing key constraints for geological models and critical input to exploration scenarios. One of the most important tasks in a typical exploration pr...Petroleum geochemistry contributes to exploration successes by providing key constraints for geological models and critical input to exploration scenarios. One of the most important tasks in a typical exploration program is to identify the most effective source intervals or kitchens in a basin, through oil-source correlation. The results of correlation are valid only if the geochemical parameters used address adequately the genetic characteristics of the source rocks as well as the mass transport and mixing processes of hydrocarbon fluids occurring in the carrier beds and reservoirs. This manuscript discusses four of the major contentious petroleum geochemical issues in China’s sedimentary basins. It is suggested that marine incursions played a significant role in the formation of prolific petroleum source rocks in the gigantic, dominantly freshwater, Songliao Basin. Several models are proposed to account for the occurrence of immature oils in the Cathaysian rift system including the Bohai Bay Basin, thus immature source rocks are considered a mere minor contributor to the known economic immature oil resources. Both geological and geochemical evidence are reviewed to refute a dominantly coaly source for the petroleum discovered in the Turpan Basin. Results of case studies are presented to demonstrate the importance of recognizing petroleum fluid mixing to solve the oil-source correlation issues in the structurally complex Tarim Basin. In addressing the fundamental assumptions and potential flaws of the molecular geochemical parameters commonly used for oil-source correlation, the need of a mass fraction approach is proposed to deal with such contentious issues as marine versus lacustrine, coal versus lacustrine, and mature versus immature oils.展开更多
The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniqu...The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniques. We use a technique of dynamic waveform matching to build cross-well stratigraphic correlation relationships and automatically draw a path diagram of the cross-well stratigraphic contrast through piecewise line fitting, log character extraction, match cost calculation, and etc.. After analyzing many structure path diagrams between wells, 30 path patterns for normal faults, reverse faults, unconformities, synsedimentary faults, listric faults, pinch-outs, and so on were summarized and the path diagram patterns and correlation conceptions are presented. The application analysis in Dagang Oil Field shows that this method is effective.展开更多
Effective carrier system comprises carrier beds which transport hydrocarbons. The spatial and temporal effectiveness of carrier system is identified according to the relevance of hydrocarbon show, hydrocarbon inclusio...Effective carrier system comprises carrier beds which transport hydrocarbons. The spatial and temporal effectiveness of carrier system is identified according to the relevance of hydrocarbon show, hydrocarbon inclusion and sealing ability of fault to hydrocarbons distribution, together with matching relation of activity history of fault and hydrocarbon generation history of source rock. On the basis of the above considerations, transporting ability of effective carrier system can be evaluated using parameters such as fluid potential, porosity and permeability, spatial coefficient of effective pathway as well as activity rate of fault. Additionally, a new concept of＂transporting threshold porosity＂ was proposed. Five styles of effective carrier systems were established in Gaoyou Sag, displaying either layered or zonal distribution characteristics, and transporting time ranges from the sedimentary time of Ezdz to early stage of sanduo uplift. Effective carrier systems can be described to be lowly-efficient and highly-efficient. Major faults （convex or steep fault plane） with activity rate greater than 20 m/Ma and structure ridges of sand layers with spatial coefficient of effective pathway greater than 25% are defined to be highly-efficient carrier beds. Hydrocarbons are concentrated around high-efficient carrier beds and E1 f traps of northern shanian area are predicted to have great potential.展开更多
Branched glycerol dialkyl glycerol tetraethers(brGDGTs),likely produced by bacteria in soil and peat,are widely distributed,easily detected,newly adopted biomarker compounds.In this study,brGDGTs were used to explore ...Branched glycerol dialkyl glycerol tetraethers(brGDGTs),likely produced by bacteria in soil and peat,are widely distributed,easily detected,newly adopted biomarker compounds.In this study,brGDGTs were used to explore the relationship between the absolute abundance of brGDGTs and the distribution of oil and gas fields in the Duoshiqiao area of the Jiyang depression.The results showed that the concentrations at the Xiakou fault and in the oil and gas fields were obviously higher than those in the contrast areas.The clear relationship among the concentration of brGDGTs,the distribution of oil and gas fields,and the acidolysis hydrocarbon(ethane)indicates that the concentration effectively responds to hydrocarbon seeps from the oil and gas field below.brGDGTs may become some of the most important indicators in surface geochemical prospecting for oil and gas.展开更多
文摘Petroleum geochemistry contributes to exploration successes by providing key constraints for geological models and critical input to exploration scenarios. One of the most important tasks in a typical exploration program is to identify the most effective source intervals or kitchens in a basin, through oil-source correlation. The results of correlation are valid only if the geochemical parameters used address adequately the genetic characteristics of the source rocks as well as the mass transport and mixing processes of hydrocarbon fluids occurring in the carrier beds and reservoirs. This manuscript discusses four of the major contentious petroleum geochemical issues in China’s sedimentary basins. It is suggested that marine incursions played a significant role in the formation of prolific petroleum source rocks in the gigantic, dominantly freshwater, Songliao Basin. Several models are proposed to account for the occurrence of immature oils in the Cathaysian rift system including the Bohai Bay Basin, thus immature source rocks are considered a mere minor contributor to the known economic immature oil resources. Both geological and geochemical evidence are reviewed to refute a dominantly coaly source for the petroleum discovered in the Turpan Basin. Results of case studies are presented to demonstrate the importance of recognizing petroleum fluid mixing to solve the oil-source correlation issues in the structurally complex Tarim Basin. In addressing the fundamental assumptions and potential flaws of the molecular geochemical parameters commonly used for oil-source correlation, the need of a mass fraction approach is proposed to deal with such contentious issues as marine versus lacustrine, coal versus lacustrine, and mature versus immature oils.
基金This work is sponsored by the Major Program in the Ninth-five Year Plan, National Natural Science Foundation of China （No.498894190 - 4）.
文摘The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniques. We use a technique of dynamic waveform matching to build cross-well stratigraphic correlation relationships and automatically draw a path diagram of the cross-well stratigraphic contrast through piecewise line fitting, log character extraction, match cost calculation, and etc.. After analyzing many structure path diagrams between wells, 30 path patterns for normal faults, reverse faults, unconformities, synsedimentary faults, listric faults, pinch-outs, and so on were summarized and the path diagram patterns and correlation conceptions are presented. The application analysis in Dagang Oil Field shows that this method is effective.
基金Project(P08045)supported by Geological Research Institute of Jiangsu Oilfield Company,SINOPEC,China
文摘Effective carrier system comprises carrier beds which transport hydrocarbons. The spatial and temporal effectiveness of carrier system is identified according to the relevance of hydrocarbon show, hydrocarbon inclusion and sealing ability of fault to hydrocarbons distribution, together with matching relation of activity history of fault and hydrocarbon generation history of source rock. On the basis of the above considerations, transporting ability of effective carrier system can be evaluated using parameters such as fluid potential, porosity and permeability, spatial coefficient of effective pathway as well as activity rate of fault. Additionally, a new concept of＂transporting threshold porosity＂ was proposed. Five styles of effective carrier systems were established in Gaoyou Sag, displaying either layered or zonal distribution characteristics, and transporting time ranges from the sedimentary time of Ezdz to early stage of sanduo uplift. Effective carrier systems can be described to be lowly-efficient and highly-efficient. Major faults （convex or steep fault plane） with activity rate greater than 20 m/Ma and structure ridges of sand layers with spatial coefficient of effective pathway greater than 25% are defined to be highly-efficient carrier beds. Hydrocarbons are concentrated around high-efficient carrier beds and E1 f traps of northern shanian area are predicted to have great potential.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCXZ-YW-JC103)contribution no.1866 from Guangzhou Institute of Geochemistry, Chinese Academy of Sciences
文摘Branched glycerol dialkyl glycerol tetraethers(brGDGTs),likely produced by bacteria in soil and peat,are widely distributed,easily detected,newly adopted biomarker compounds.In this study,brGDGTs were used to explore the relationship between the absolute abundance of brGDGTs and the distribution of oil and gas fields in the Duoshiqiao area of the Jiyang depression.The results showed that the concentrations at the Xiakou fault and in the oil and gas fields were obviously higher than those in the contrast areas.The clear relationship among the concentration of brGDGTs,the distribution of oil and gas fields,and the acidolysis hydrocarbon(ethane)indicates that the concentration effectively responds to hydrocarbon seeps from the oil and gas field below.brGDGTs may become some of the most important indicators in surface geochemical prospecting for oil and gas.
