Study On Reservoir Geological Model Of Heavy Oil Reservoir In K Block Of Littoral Caspian Basin

The study area is located on the Yanbek-Zalkames uplift about 220 km south of the Asthan-Aktyubins clone on the eastern edge of the Caspian Basin,and the heavy oil reservoir in the study area is characterized by shallow burial depth.With the increase in the exploration and development of Cretaceous reservoirs in the study area in recent years,it is necessary to use the method of reservoir geological modeling to study the characteristics of reservoirs and the distribution of reservoirs in the study area to provide a theoretical basis for the development of the next oil field.This paper,by using logging data,core data and the casting thin sections,scanning electron microscopy,relative permeability experiments,such as the lower cretaceous in the study area for the stratigraphic classification,the characteristics of sedimentary facies,reservoir characteristics and logging secondary interpretation,etc.,finally,the study area to make use of geologic modeling software Petrel stochastic modeling,structure model is established,lithology model and property model.The results show that the Cretaceous system in the study area develops a set of meandering river delta-lake sedimentary systems,of which K1br-1 and K1h are shallow lake-pre-delta sedimentary subphasic,and K1br-2 is the delta leading subphysic.The Cretaceous reservoir sandstone type is clastic sandstone,the lithology is dominated by fine sandstone,followed by siltstone,the reservoir clastic particles are sorted,etc.the roundness is sub-circular-sub-angular,the cement type is pressed-porosity type,the cementation is loose,the contact relationship is line-point contact,the support type is particle support,and the sandstone maturity is low.In terms of reservoir physical properties,the average porosity of the K1br-1 core is 34.4%,the average permeability is 181.9×10^-3μm²,which is a very high-porosity-medium permeable reservoir;the average porosity of the K1br-2 core is 36.9%,the average permeability is 553.1×10^-3μm²,which belongs to the ultra-high porosity-hyperosmolar reservoir;the average porosity of the K1h layer core is 36.4%,and the average permeability is 115.5×10^-3μm²,which is a very high-porosity-medium permeable reservoir.The main oil layer in the study area is K1br-2,followed by K1br-1,and the K1h layer is basically oil-free,of which the average oil layer thickness of K1br-1 is 2.4m,and the average thickness of K1br-2 is 19.4m.Using Petrel calculations,it was learned that the crude oil reserves in the study area were about 3.478 million tons.