Research On Logging Evaluation Method Of Reservoir Pollution Damage

With the continuous development of the oil industry,People pay more attention on the problem of reservoir damage,and evaluate the reservoir pollution degree of damage with logging data can be more intuitive to show the potential pollution damage of the reservoir,and provides the effective support to the implementation of the reservoir protection in the oil field.In this paper,we first analyze the formation factors that affect the degree of reservoir sensitivity,and establish a well logging calculation model of the formation factors through the data of well logging,thin slice,physical property and image forming,and screened the high correlate factors on the basis of the single correlation analysis between reservoir sensitivity and the influence factors.Establish the logging prediction model for reservoir sensitivity by multiple regression method,and realized the prediction of reservoir sensitivity by using well logging data.By the large number of documents,found mud invasion is the most important factor affecting the degree of reservoir pollution,and in the mud invasion process,the mud filtrate invasion depth is mainly affected by the difference between formation pressure and wellbore mud column pressure,therefore,the prediction of formation pressure for the evaluation of reservoir pollution is of great significance.In this paper,the formation pressure prediction model which is suitable for the local area is established by various methods,and comparative analysis of the calculation results to determine the method in which the highest accuracy.The four parameter inversion method is used in the calculation of the mud fluid invasion depth,and the calculation model of mud solid invasion depth is established on the inversion results.Through the the single correlation analysis between the influence factors of reservoir pollution degree and the reservoir pollution assessment parameter named permeability damage ratio,established a permeability damage ratio model that applied to the 8th member of xiashihezi formation in the south of Sulige gas field to determine the reservoir in this region is light polluted,and provides strong support for the protection of reservoir in the oil field.