Study On Geological Modeling And Reserve Calculation Of Chang6 In Chaishangyuan Area Of Ordos Basin

Using various data such as well logging,logging,mercury injection and phase permeability to calculate the reserves,study the 3D geological modeling,evaluate the utilization degree and study the distribution law of remaining oil of chang 6 reservoir.Combined with the geological background of this area,the structural characteristics are analyzed,and the results show that oil layer of the chang 6 reservoir has simple structure,each small layer has strong integration,and the tectonic amplitude is small.Exquisitely study the relationship between the well logging curves,physical properties and the degree of saturation,summarizes four property relationship of chang 6 reservoir,using the equation of the porosity and interval transit time to calculate porosity,using a variety of methods to determine limit of net pay thickness:porosity 7%,permeability 0.2mD,oil saturation threshold 43%,interval transit time 215 mu s/m,resistivity 47?·m.Using oil base mud coring analysis,mercury injection test and archie formula to determine the original oil saturation of the reservoir,volume weighting is used to determine the calculation parameters of reserves in each layer,according to the calculation results of reserves,chang 6 reservoir belongs to medium abundance reservoir with reserves abundance of 43.65×104t/km2 and proven geological reserves of 1250.09×104t.With reference to the manual drawing of the structure map,the stratigraphic model is established by the sequential indication method,and the lithological model is established by the well point constraint and the vertical attribute probability constraint,the sequential gaussian simulation,phased control constraint,collaborative simulation constraint and the regulation and optimization of the variation function are used to eatablished the porosity model,permeability model,saturation model and Ntg model.The resoults show that the coarse data with multiple constraints and sequential simulation method can establish a more accurate 3D geological model,the heterogeneity between reservoir and interlayer is fully considered in geological modeling,which can better solve the problem that traditional volumetric method fails to consider.Research on the law of decline shows that the law of production decline is the law of exponential decline and the decline rate is relatively stable,the monthly decline rate of liquid production is 0.93%,the annual decline rate is 10.4%,the monthly decline rate of oil production is 1.02%,the annual decline rate is 11.4%,the monthly decline rate of water production is 1.7%,the annual decline rate is 18%.The study on the level of exploitation shows that the chang6 reservoir generally has a low exploitation level and chang622 has the highest exploitation level,on the plane,the southwestern and northeastern regions of the study area have high degree of utilization,while the southern,northwestern and central regions have low degree of utilization.The distribution characteristics of residual oil are determined by the relative permeability experiment and numerical simulation of reservoir,the residual oil distribution rule shows that the average residual oil saturation is 48.6%,the parts with higher remaining oil saturation are mainly located in the northeast of the study area and the west of the study area,and the N86-5 well area in the middle.