Study On The Well Logging Interpretation Models Of Tight Sandstone Reservoir Of Chang 8 Oil Formation In Honghe Oilfield

Chang 8 oil formation in Honghe oilfield is low porosity low permeability tight sandstone reservoir,which has poor physical properties,poor pore structure and strong heterogeneity.Conventional log interpretation methods cannot meet the needs of the fine reservoir description and complex reservoir parameter interpretation is difficult.There usually has two ways of improving reservoir parameter interpretation accuracy through conventional logging data,one is based on the analysis of genetic mechanism to make the establishment of genetic classification interpretation model;the other is to use non-linear mathematical method to find nonlinear relationship between the data implied to improve the interpretation accuracy.In this paper,geological classification and mathematical method is combined to achieve better prediction results of reservoir parameters.Firstly,the macro and micro characteristics of the reservoir are studied by using the data of cores,drilling and logging data.It was suggested that deposition,digenesis and tectonics leads to the complex reservoir conditions.Sedimentary leads to lithology changes,and digenesis makes complex pore structure characteristics,and tectonics plays a role in the structural fracture development.These factors will lead to changes in the characteristics of reservoir performance,well logging response and rock electric response.Fracture is the main factor that causes the complexity of reservoir type and the logging response characteristics in the study are.Therefore,the reservoir is divided into three types: fracture type,fracture pore type,pore type.A variety of methods are used to improve the identification accuracy of the fracture to make the classification of reservoir.On the basis of the geological genetic classification,this article uses many kinds of mathematical methods including the kernel method which has a better effect of solving the nonlinear problem,to explain reservoir parameter in the study area and establish the logging interpretation model.Results show that the porosity model by using the kernel method after the classification,unit permeability model by using flow unit,and oil saturation model by using different rock electrical parameters have a better effect.The reservoir classification evaluation is carried out using the interpretation results,and comprehensive reservoir I,II,III type have a certain corresponding relationship with the production characteristics,which shows a better application effect.