Heterogeneity Of N₂¹ Reservoir In Zha 9 Well Area Of ??Qaidam Basin

According to reservoir description, reservoir geology, oil field geology, logging geology and other related disciplines, using well logging, logging data and laboratory analysis data,comprehensive application of core, mud logging and well logging data by mark layer method, slice comparison method, by division and comparison of reservoirs and small layer, and according to the lithologic features, electrical characteristics, cycle characteristics, the layer of sand group are divided into eight sets of sand group, which the main layer is the Xiayoushashan ? group and ? group. The study concluded that the main purpose of the study area is shallow lake subfacies. Shallow lake subfacies include sand dam (dam, dam edge), beach and bar and shallow lake mud microfacies.From the perspective of the distribution of microfacies, facies and plane bar sand developed center dam, connected the dam edge, sand body connectivity better; but in the lateral, to the contiguous poor sand body, center dam, dam edge, dam, lake sediment phase appear. Relative to the sand dam, the beach is smaller. Local interlayer is the most developed in the zha 9 area, but the frequency of the interlayer is very large. The frequency of the interlayer in the dam is low or zero, but the dam edge and the beach with the high frequency, the frequency is increased gradually.from the dam to dam edge.Evaluated the heterogeneity of the zha 9 area through the ariation coefficient of permeability, permeability max-mean ratio. Studies suggest that IV-27 layers in the zha 9-3-6 well area and zha 9-1-1 well area with the weak heterogeneity and the rest is strong;?-2-1 layer heterogeneity is stronger from north to South;?-2-2 layer heterogeneity is stronger from north to South, but the strongest heterogeneity is in the zha 9-1-2 well area, the weakest is in the zha 9-2-8 well area; the strong heterogeneity of the region in ?-2-3 layer is located in southwest of the study area of beach phase, northeastern area of beach phase heterogeneity is relatively weak, but heterogeneity is increased from east to west. Conducted the research on the reservoir heterogeneity with the variation coefficient of permeability,permeability max-mean ratio.Studies suggest that the VID-2-2 layer with the high heterogeneity in the zha 9 area;the ?-2-3 layer with the medium heterogeneity;the rest with the weak heterogeneity. Interlayer thickness changes due to layer varies,in generally, the interlayer thickness of ?-2-1 to ?-2-2 in zha 9 area is less than 1 m in the west of zha 9-4-8 to zha 9-1-1, the rest area is 1 to 2 meters; ?-2-2??-2-3 layer with the thickness from southwest to northeast, but not more than 3 meters.