Remaining Oil's Distribution Regularities In Different Sand Body In The Southern District Of Xingshugang Oilfield

Continental reservoir has strong reservoir heterogeneity;sand body's property has strong diversity because of the different contributing factors.In the process of water flooding,the injected water would move along the high permeability zone generally;and make the remaining oil's distribution in different genetic sand bodies became more complex.The detailed study of different sand bodies' characteristics and its influence of residual oil distribution have important significance in taking different excavate methods to improve the remaining oil's recovery efficiency.Based on the modern theory of sedimentology,reservoir geology,under the guidance of integrated data,such as core,logging,laboratory analysis,this paper has researched the PI group's strata sedimentary characteristics in the southern district of Xingshugang oilfield;and has divided the main sand body in the study area into meander-type distributary channel,straight-type distributary channel,the main body sand sheet,the non-main body sand sheet and untabulated reservoir five types.The research results show that the meander-type distributary channel has the strongest heterogeneity,good physical property,high permeability heterogeneity parameters,and could develop lateral accretion interface layer.The straight-type distributary channel's all heterogeneity parameters was lower than those of meander-type distributary channel,different kind of sand sheet's heterogeneity is weaker than the channel sand,and the size of the heterogeneity parameters is associated with the thickness of sand body,the greater the thickness,the stronger the heterogeneity.Based on the above research,this paper has studied the remaining oil's distribution pattern in different sand bodies.The remaining oil always distributed in the upper part of meander-type distributary channel's sand body.The remaining oil distributed in the upper part of straight-type distributary channel's sand body.But the upper part remaining oil of straight-type distributary channel is relatively less than that of I-type sand body,while the lower part remaining oil is much more than that of I-type sand body.In the plane,the remaining oil is mainly distributed in the river side.The remaining oil's distribution is related with the thickness of sand body in the main-body sand sheet and the non-main body sand sheet.The remaining oil is distributed in the upper part when the sand body is much thick,otherwise in the lower part.Untabulated reservoir is thin,which has a bad poroperm characteristic and water injection effect.As a whole,the untabulated reservoir has more remaining oil.