The Microstructure Study Of Chang 6₃ Reservoir In Longdong Huaqing Area

Pore radius of low permeability reservoir is small,and its throat distribution is complicated,its microstructure is different from conventional reservoir.With the study of low permeability reservoirs in recent years,it has been found that the microscopic pore structure of reservoirs has a fundamental influence on the physical properties of the reservoir and has an important influence on the seepage of the reservoir.In this paper,the microstructure of the Chang 6₃ reservoir in the Longdong Huaqing area in Ordos Basin was studied by high pressure mercury intrusion,constant pressure mercury intrusion and nuclear magnetic resonance technique.The microstructure of the reservoir was quantitatively characterized by quantitative analysis of the pore structure parameters Reservoir microstructure characteristics,the main understanding of the following:?1?The homogenization coefficient of reservoir pore throat structure is between 0.01 to2.38,the tortuosity is between 0.01 to 2.81,the span is larger,and the main seepage pore is obviously biased towards large pore.Through the study of the correlation between reservoir physical properties,it is found that the correlation is generally poor,the reservoir heterogeneity is strong,the pore throat morphology changes obviously,and the pore throat ratio is not obvious.?2?Permeability is controlled by the distribution and configuration of the pore throat.The contribution of the porosity of the reservoir to the mercury saturation is greater than that of the throat,but the difference is not obvious,indicating that the porosity can provide the main effective storage space.?3?The fractal dimension of reservoir length 6₃ is between 2.05 to 3.15,and the average value is about 2.33.The fractured structure of rock pore throat is influenced by pore size and pore throat,which is mainly expressed by fractal dimension,the fractal dimension of the low permeability reservoir has a good correlation with the physical parameters,which can be used as the main parameters of the evaluation of the physical properties of the low permeability reservoir.?4?The study area 6₃ reservoir pore sorting medium good,wide pore size distribution,movable fluid saturation between 36.75% to 55.54%,movable fluid porosity between 1.95%to 7.59%,The movable fluid and the physical parameters have obvious correlation,which is an important reservoir evaluation parameter.