The Microheterogeneity Study Of Chang 6₃ Reservoir In Longdong Huaqing Area

The low permeability reservoir has the characteristics of complex pore and throat distribution and poor physical property,and the seepage ability of the reservoir is relatively poor compared with the conventional reservoir.With the study of low permeability reservoirs in recent years,it is found that the microstructure characteristics of the reservoir have an important influence on the reservoir physical properties and reservoir seepage.This paper by the method of casting thin sections,high-pressure mercury injection and atomic force microscopy in the ordos basin Longdong HuaQing region length and Chang 6₃reservoir to study reservoir microstructure,and investigated Chang 6₃¹ reservoir,Chang 6₃²reservoir,and Chang6₃³reservoir micro structure of the reservoir characterization,by comparing the properties of each layer and atomic force microscopy images,to analyze the microstructure characteristics,reservoir mainly has the following understanding:?1?The reservoir developed fine grained feldspar sandstone,subaltern,and medium,the main types of cementation were pore cementation,intergranular pores,and a small amount of feldspar.The size separation of the Chang 6₃³reservoir is the best,the physical property is good,and the Chang 6₃²reservoir is relatively poor.?2?The correlation coefficient between porosity and sorting coefficient of Chang6₃³ reservoir R² is about 0.1067,and the correlation coefficient R2 between permeability and sorting coefficient is about 0.3277,and porosity and permeability are better than those of Chang 6₃¹ reservoir and Chang 6₃² reservoir.The correlation between porosity and coefficient of variation is the best in Chang 6₃³ reservoir,and the heterogeneity in Chang 6₃³ reservoir is relatively weakest.For Chang 6₃² reservoir,when the coefficient of variation is between 0.05⁰.1,permeability is more concentrated.?3?Permeability and material parameters correlation is generally poor,Chang6₃ reservoir heterogeneity of Chang 6₃² reservoir variation coefficient and separation coefficient correlation compared to the best,the highest correlation coefficient was0.98,Chang 6₃² reservoir microscopic heterogeneity compared with the other two layers of the strongest,Chang 6₃³ reservoir microscopic heterogeneity in reservoir was the weakest.Property comparison,Chang 6₃² reservoir microscopic heterogeneity.?4?Through the atomic force microscope experiment,the roughness parameter of the Chang 6₃³ reservoir is relatively small,the reservoir seepage capacity is relatively strong,and the reservoir property is relatively good.The more abundant the throat type in the sample,the more varied the variation,and the greater the influence of distribution and homogeneity on the pore throat structure,the stronger the microheterogeneity of the reservoir.?5?Through statistical analysis of parameters,the Chang 6₃ reservoir micro-heterogeneity assessment system was established.Chang 6₃¹ reservoirs were classified as Type II reservoirs,and Chang 6₃² reservoirs were classified as Type I reservoirs.The Chang 6₃³ reservoir was divided into IIIreservoirs.