Research On Control Function Of Reservoir Forming Of Oil And Gas Transporting System In Wen’an Slope Of Baxian Sag

In order to study oil and gas transportation system and controlling function of reservoir forming of Wen ’an slope in Baxian depression, First of all, according to the test, well logging, mud logging data analysis of characteristics of oil and water distribution and reservoir type,based on hydrocarbon source rock vertical thermal evolution stage,divide hydrocarbon generation and hydrocarbon expulsion threshold,identify unconformity type by seismic features,identify three layers structure of unconformity By logging,based on the unconformity connected wells profile and oil and gas enrichment of unconformity three layers structure, identify unconformity transportation channel characteristics. Count the relationship between the reservoir sandstone ratio and the oil and gas show,determine sandstone ratio the lower limit of sand connecting,determine sand connecting scope by sandstone ratio the lower limit,track structure ridge of sand connecting scope,determine the advantages of migration path. On the basis of the analysis of the characteristics of the faults geometry and the history of formation and evolution,divide faults system,on the basis of fracture system and hydrocarbon accumulation critical period set transportation faults and shelter faults. Eventually determine the type of oil and gas transportation systems, Through the cover thickness plane distribution characteristics and lower limit of transporting faults and cover configuration determine distribution characteristics of oil and gas transportation systems type. Determined hydrocarbon migration pathway by comprehensive numerical simulation of oil and gas migration, through nitrogen compounds changes tracer analysis was carried out on the oil and gas migration direction. The results show:Oil and gas mainly distribute in Es1 and Es2, give priority to with fault nose reservoir, followed by the block; Oil threshold is 3100 m, oil generation peak is 4400m;The unconformity layer almost does not contain oil and gas, So the unconformity is not the main channels for lateral hydrocarbon migration;The sandstone lower limit 0.14 of sand connecting of Es1, the sandstone lower limit 0.17 of sand connecting of Es2, the advantages of conducting channels of sand conducting layer of Es1 and Es2 are nearly east-west or north east to stretch, Currently submitted reserves and oil flow Wells basic are located on or near the advantages of migration path. Wen’an slope develop six sets of fracture system:Ⅰ. early extensional fault systems、Ⅱ.middle strike slip and extensional faults system、Ⅲ. late transtensional faults system、Ⅳ. early extensional—middle strike slip and extensional faults system、Ⅴ. middle strike slip and extensional—late transtensional faults system、Ⅵ. early extensional—middle strike slip and extensional—late transtensional faults system, the types of transportation faults system is mainly for Ⅳ、Ⅵ and part Ⅱ、Ⅴ; There are two major types of transportation systems, namely, oil and gas lateral transportation system with the same lay、oil and gas lateral transportation system with the across lay, the oil and gas lateral transportation system with the same lay mainly distribute in closed area of research area inner zone, the oil and gas lateral transportation system with the across lay mainly distribute in enclosed area of research area middle and outer zone; There are two major types of transportation systems, namely, oil and gas lateral transportation system with the same lay、oil and gas lateral transportation system with the across lay, the oil and gas lateral transportation system with the same lay mainly distribute in closed area of research area inner zone, the oil and gas lateral transportation system with the across lay mainly distribute in enclosed area of research area middle and outer zone; The result of oil and gas comprehensive numerical simulation are consistent with the reserves of we have already submitted, oil- gas mainly carry on the lateral migration and local adjust by vertical faults.The oil and gas lateral transportation system with the same control the oil and gas gathering under cover closed area, the oil and gas lateral transportation system with the across control the oil and gas main gathering above cover enclosed area, dfferent transportation systems have different control functions for oil and gas accumulation.