Orderly distribution of oil and gas and the main controlling factors for the differential hydrocarbon enrichment in Nanpu Sag
The distribution order of oil and gas is a major means to characterize the law of differential hydrocarbon enrichment,providing an important basis for the identification of replacement orientations.The systematic analysis has been conducted,including oil and gas reservoir types,oil and gas properties,degree of hydrocarbon enrichment,hydrocarbon transport system and fault-cap rock conditions,which supports to determine the main controlling factors for the orderly distribution and differential enrichment of oil and gas in Nanpu Sag.The study results show that,from the center to the margin of sub-sags in Nanpu Sag,it shows an orderly change from lithologic oil and gas reservoirs to structural oil and gas reservoirs,the crude oil properties gradually deteriorate,and hydrocarbon gradually enriches in shallower formations.The tectonic activities during the fault and depression periods controlled the distribution and evolution of source rocks,and the tectonic evolution controlled the sedimentary system in the sag and the distribution of reservoir-cap rock combinations and trap type.Among them,three types of reservoir-cap rock combinations below,within and above source rock laid the foundation for multi-layer hydrocarbon distribution.The vertical and lateral transport system and the differential fault-cap rock configuration controlled the process of hydrocarbon migration and accumulation in different structural belts,forming the general law of hydrocarbon enrichment below source rock in the central sag and above source rock in the marginal sag.The study results further reveal the regular distribution of oil and gas in the sag,which provide theoretical guidance and reference for the fine exploration in mature exploration areas.
Nanpu Sagorderly distribution of oil and gashydrocarbon accumulation elementstransport systemdifferential hydrocarbon enrichment
万方数据
维普
