Reservoir Bed Geology Study Of Jinzhou 9-3 Oilfield

The water-cut of Jinzhou 9-3 oilfield was high after producting 5 years. Many problems are very big like that the recovery percent of reserves is low, the red of the east part of oilfield is very serious, the breakthrough along a single layer is serious by edge water and injecting water, the product decline factor is high and so on. Aimming at these problems, Reservoir Bed Geology Study of Jinzhou 9-3 Oilfield was coming into being. The study includes the reservoir fine subdividing, sedimentary microfacies dividing and identifying and reservoir heterogeneity study.Reservoir fine subdividing and correlation were done using the method that is the isochronous cycle correlation controlled by key beds and base on sedimentary facies, owing to the character of the oilfield and the requirement of study. 10 oil-groups were subdivided into 33 members. After this, subdivided and identified sedimentary microfacies were done based on the data of core, seism and log. There are several microfacies that they are underwater distributary channel, river mouth bar, distal bar, sheet sand, interchannel in the area. After that, the sedimentary microfacies maps were appeared. At last, the distributing character and rule of the individual layers were found. The main oil reservoir bed is developed. The source area is north-east. The distribution direction of the sand body is from north-east to south-west. The source areas are two. The range of porosity and permeability in the plane is large. The high permeability of reservoir is at shallow structure and lower is deeper. The conclusion is the heterogeneity of Jinzhou 9-3 oilfield is high through the study of microcosmic and macroscopical heterogeneity, analysis of interbed, the production dynamic data and test data. The reason was found that the water-cut raised soonly. It is the base to improve the development of injecting water.In the condition of high heterogeneity reservoir bed, the main reason of breakthrough along a single layer is that the water intake per unit thickness is too high. The oilfield took several measures that was increasing injection wells or converted injection wells to decrease the water intake per unit thickness, profile modification and separate injecting water. The development and recovery factor was improved.