Study On The Distribution Characteristics Of Permian Reservoir Fluid Potential In Hangjinqi Area, Ordos Basin

Hangjinqi exploration area is an important petroleum region in the north of Ordos Basin.The study of hydrocarbon accumulation period and fluid potential is conducive to the fine exploration of hydrocarbon accumulation evolution and migration trend.This paper takes five wells in Shiguhao block and Shiligahan block,and takes the reservoir sandstone of He 1 member of Lower Shihezi Formation of Permian as the research object.The purpose of the research is to clarify the key accumulation period and the distribution characteristics of fluid potential in the study area by combining the experimental analysis of fluid inclusions with the theory of fluid potential.The results show that the capture temperature of oil inclusions is 100℃～124℃,and the capture pressure is 179bar～239bar.The capture temperature of methane inclusions is 122℃～128℃,and the capture pressure is 181bar～185bar.In the reservoir of Shiligahan block,the capture temperature of petroleum inclusions is 105℃～140℃,the capture pressure is 202bar～323bar,the capture temperature of methane inclusions is 106℃～111℃,and the capture pressure is 210bar～214bar.Combined with the burial history of single wells,Shiguhao block in the study area has two stages of reservoir formation: the first stage of petroleum accumulation time is 132Ma～103Ma,and the first stage of natural gas accumulation time is 108Ma～102Ma.Shilijiahan block also has two stages of accumulation: the first stage of petroleum accumulation time is132Ma～101Ma,and the first stage of natural gas accumulation time is 130Ma～120Ma.Based on the calculation results of fluid density,fluid pressure and paleoelevation parameters,the fluid potential of petroleum in the north of Hangjin Banner: the average value of well Jin 67 and well Jin 81 in Shiguhao block is 22872J/kg and 21172J/kg respectively;the average value of well Jin 7,well Jin 53 and well Jin 91 in Shiligahan block in the south is 24843J/kg,26513J/kg and 27153J/kg respectively.The fluid potential of natural gas in the study area: the average value of well Jin 81 is 18128J/kg and that of well Jin 53 is 22975J/kg.Comprehensive analysis shows that Shiligahan block is a high potential area relative to Shiguhao block,petroleum and natural gas have the trend of migration from the south to the north.