Study On Reservoir Characterization Of Density Sandstone In Hanqu-dongrengou Area

Chang 2₁¹ oil segment of Triassic in Ordos Basin are low-permeability sandstone reservoir. Intensely nonuniformity of reservoir and complexity relationship between oil and water result in difficult exploration and development. By the reservoir characteristics and oil water distribution of the area, in combination with the distribution of the characteristic of flow units, further improve the structure-lithologic reservoir reservoir description technology, ideas and methods, and provides an important theoretical and practical significance for future studies of similar reservoir.Based on core, logging and oil test data, combined with the results of previous studies, use methods of conventional geology, logging, cast thin section, scanning electron microscopy, mercury injection, water flooding oil test methods and cluster analysis, discriminant analysis, etc.compute technique, sandstone distribution, reservoir characteristics, distribution of flow unit, reservoir characteristics and oil-water distribution of Chang 2₁¹ oil segment were reseached deeply and comprehensively.The main recognition includes: the sandstone reservoir was formed in geometry lens depositional environment for the environment of delta plain subfacies. reservoir heterogeneity is intensely and sandstone geometry presents lens shape. Reservoirs are divided into three classâ… (high-quality reservoir),â…¡(middle reservoir),â…¢(poor reservoir) reservoir, andâ… â…¡classify is the main reservoir of Chang 2₁¹ oil segment. Flow unit are divided into A, B, C, D classify. Classify A and B are mainly distributed in the middle part of distributary channel sandstone and structural nose, as well as thick sandstone lying in the crossing place of two distributary channel; Classify are mainly distributed in the distributary channel, Classify D lies in the distributary channel edge , swamps, low-lying land of the distributary channel and so on. Nature of Oil bearing of four classifys above decrease gradually. Oil-bearing was mainly affected by sedimentary facies and sand body distribution. The regular pattern is: favorable sedimentary facies, sandstone thickness, weak heterogeneity results in the higher the oil level.