Objective Oil-source faults have an important effect on reservoir formation and distribution in shallow formations with non- hydrocarbon generation in oil-rich fault-related basins （Jiang Youlu et al., 2015）. Howev...Objective Oil-source faults have an important effect on reservoir formation and distribution in shallow formations with non- hydrocarbon generation in oil-rich fault-related basins （Jiang Youlu et al., 2015）. However, the fault transporting capacity cannot be evaluated quantitatively at present. Taking the Zhanhua Sag in the Bohai Bay Basin as an example, this work analyzed the factors influencing the transporting capacity of the oil-source faults and proposed a quantitative method for evaluating their transporting capacity.展开更多
The ability of faults to transport oil and gas is affected by multiple geological factors,and the effects of various factors on oil and gas migration and accumulation are complex.In this study,based on the drilling an...The ability of faults to transport oil and gas is affected by multiple geological factors,and the effects of various factors on oil and gas migration and accumulation are complex.In this study,based on the drilling and three-dimensional seismic data in the No.4 structural zone of the Nanpu Sag and by considering the effects of fault throw,caprock thickness,shale content,fluid pressure,stress normal to the fault plane,and brittleness,we employed fault transport index(FTI)to quantitatively characterize the vertical transport ability of regional faults.Through statistical analysis,fault transport probability(N_p)was used to characterize the relationship between FTI and the vertical hydrocarbon content in the formations,The results show that the faults with FTI less than 0.75 cannot transport oil and gas,while those with FTI greater than 2.5 are able to transport oil and gas.Specifically,when FTI is between 0.75and 2.5,there is a functional relationship between the probability of faults transporting hydrocarbons and FTI.The current oil and water distribution and paleo oil reservoir test results indicate that there are oil layers or paleo oil reservoirs in horizons with large N_(p).Therefore,FTI can be used as an effective coefficient to indicate the vertical migration paths and accumulation spots of hydrocarbons moving along faults,providing an essential reference for further oil and gas exploration and development.展开更多
Significant differential hydrocarbon enrichment occurs in depressions in a petroliferous basin.There are multiple depressions in the Bohai Bay Basin, and each depression as a relatively independent unit of hydrocarbon...Significant differential hydrocarbon enrichment occurs in depressions in a petroliferous basin.There are multiple depressions in the Bohai Bay Basin, and each depression as a relatively independent unit of hydrocarbon generation, migration and accumulation, contains significantly different hydrocarbon generation conditions and enrichment degree. On the basis of previous documents and a large number of statistical data, this work comparatively analyzed the differential hydrocarbon enrichment and its major controlling factors in depressions of the Bohai Bay Basin. The results show that depressions in the Bohai Bay Basin have various hydrocarbon enrichment degrees, and can be categorized into four types, namely enormously oil-rich, oil-rich, oily and oil-poor depressions. In general, the enormously oil-rich and oil-rich depressions are distributed in the eastern part of the basin along the Tan-Lu and Lan-Liao faults, whereas depressions in the western part of the basin are poor in hydrocarbons. Moreover, the vertical distribution of hydrocarbons is also highly heterogeneous, with Pre-Paleogene strata rich in hydrocarbons in the northern and western depressions, Paleogene strata rich in hydrocarbons in the entire basin, and Neogene strata rich in hydrocarbons in the off-shore areas of the Bohai Bay Basin. From early depressions in onshore areas to the late depressions in offshore areas of the Bohai Bay Basin, the source rocks and source-reservoir-cap rock assemblages gradually become younger and shallower, and the hydrocarbon resource abundance gradually increases. Hydrocarbon supplying condition is the key factor constraining the hydrocarbon enrichment for different depressions,while the main source-reservoir-cap rock assemblage, sufficient hydrocarbons and the transportation capacity of faults control the vertical distribution of hydrocarbons. The main factors controlling hydrocarbon enrichment are different for different layers. The hydrocarbon supplying condition of source rocks is the key controlling factor, whereas the source-reservoir configuration, the main sourcereservoir-cap rock assemblages, and the fault transportation are the main factors of hydrocarbon enrichment in the Paleogene, Paleogene and Neogene, respectively.展开更多
基金granted by the National Natural Science Foundation of China(grant No.41672131)Fundamental Research Funds for the Central Universities(grant No.16CX06045A)
文摘Objective Oil-source faults have an important effect on reservoir formation and distribution in shallow formations with non- hydrocarbon generation in oil-rich fault-related basins （Jiang Youlu et al., 2015）. However, the fault transporting capacity cannot be evaluated quantitatively at present. Taking the Zhanhua Sag in the Bohai Bay Basin as an example, this work analyzed the factors influencing the transporting capacity of the oil-source faults and proposed a quantitative method for evaluating their transporting capacity.
基金supported by the National Natural Science Foundation of China(Grant Nos.42302150 and U20A2093)National Science and Technology Major Project(Grant No.2024ZD1400104)。
文摘The ability of faults to transport oil and gas is affected by multiple geological factors,and the effects of various factors on oil and gas migration and accumulation are complex.In this study,based on the drilling and three-dimensional seismic data in the No.4 structural zone of the Nanpu Sag and by considering the effects of fault throw,caprock thickness,shale content,fluid pressure,stress normal to the fault plane,and brittleness,we employed fault transport index(FTI)to quantitatively characterize the vertical transport ability of regional faults.Through statistical analysis,fault transport probability(N_p)was used to characterize the relationship between FTI and the vertical hydrocarbon content in the formations,The results show that the faults with FTI less than 0.75 cannot transport oil and gas,while those with FTI greater than 2.5 are able to transport oil and gas.Specifically,when FTI is between 0.75and 2.5,there is a functional relationship between the probability of faults transporting hydrocarbons and FTI.The current oil and water distribution and paleo oil reservoir test results indicate that there are oil layers or paleo oil reservoirs in horizons with large N_(p).Therefore,FTI can be used as an effective coefficient to indicate the vertical migration paths and accumulation spots of hydrocarbons moving along faults,providing an essential reference for further oil and gas exploration and development.
基金granted by the Important National Science&Technology Specific Projects(grants No.2011ZX05006-003 and 2016ZX05006-003)the National Natural Science Foundation(grant No.41372132)
文摘Significant differential hydrocarbon enrichment occurs in depressions in a petroliferous basin.There are multiple depressions in the Bohai Bay Basin, and each depression as a relatively independent unit of hydrocarbon generation, migration and accumulation, contains significantly different hydrocarbon generation conditions and enrichment degree. On the basis of previous documents and a large number of statistical data, this work comparatively analyzed the differential hydrocarbon enrichment and its major controlling factors in depressions of the Bohai Bay Basin. The results show that depressions in the Bohai Bay Basin have various hydrocarbon enrichment degrees, and can be categorized into four types, namely enormously oil-rich, oil-rich, oily and oil-poor depressions. In general, the enormously oil-rich and oil-rich depressions are distributed in the eastern part of the basin along the Tan-Lu and Lan-Liao faults, whereas depressions in the western part of the basin are poor in hydrocarbons. Moreover, the vertical distribution of hydrocarbons is also highly heterogeneous, with Pre-Paleogene strata rich in hydrocarbons in the northern and western depressions, Paleogene strata rich in hydrocarbons in the entire basin, and Neogene strata rich in hydrocarbons in the off-shore areas of the Bohai Bay Basin. From early depressions in onshore areas to the late depressions in offshore areas of the Bohai Bay Basin, the source rocks and source-reservoir-cap rock assemblages gradually become younger and shallower, and the hydrocarbon resource abundance gradually increases. Hydrocarbon supplying condition is the key factor constraining the hydrocarbon enrichment for different depressions,while the main source-reservoir-cap rock assemblage, sufficient hydrocarbons and the transportation capacity of faults control the vertical distribution of hydrocarbons. The main factors controlling hydrocarbon enrichment are different for different layers. The hydrocarbon supplying condition of source rocks is the key controlling factor, whereas the source-reservoir configuration, the main sourcereservoir-cap rock assemblages, and the fault transportation are the main factors of hydrocarbon enrichment in the Paleogene, Paleogene and Neogene, respectively.
