Reservoir characteristics and high yield control factors of Permian Fengcheng Formation shale oil reservoir in Mahu Sag
Based on the experimental results of rock slices,scanning electron microscopy,low temperature nitrogen adsorption,high pressure mercury injection,core fluorescence,laser confocal microscopy and liquid production profile,the characteristics and high yield control factors of Permian Fengcheng Formation shale oil reservoir in Mahu Sag were detailed studied.The results show that:(1)The shale oil reservoirs of Permian Fengcheng Formation in Mahu Sag can be divided into sandstone,dolomite and mudstone.Siltstone reservoirs are dominated by terrigenous clastic sediments,mudstone reservoirs are dominated by terrigenous and endogenous mixed deposits,and dolomite(calcite)reservoirs are dominated by endogenous chemical deposits.The throat size distribution ranges of sandstone,dolomite and mudstone reservoir of Fengcheng Formation in Mahu Sag decrease successively,and the pore connectivity of the three lithologic reservoirs deteriorates successively.(2)Siltstone reservoirs have the best oil content,followed by mudstone reservoirs,dolomite reservoirs are the worst of shale oil reservoirs of Permian Fengcheng Formation in Mahu Sag.The proportion of free oil is higher in the larger pores and micro-fractures,and the proportion of adsorbed oil is higher in the smaller pores.(3)High quality source rock and high quality reservoir control the high production area and high production interval of Fengcheng Formation in Mahu Sag,respectively.The shale oil reservoirs with high felsic content,effective porosity,free oil porosity,fracture density and brittleness index are the favorable interval for high production.
shale oil reservoirlow temperature nitrogen adsorptionpore size distributionfree oiladsorbed oilfracture densitybrittleness indexFengcheng FormationPermianMahu Sag
万方数据
维普
