Research On Dynamic Evaluation Of Reservoir Methods By Array Induction Logging

Drilling fluid filtrate into the reservoir is a complex physical process which has an important impact on logging interpretation and evalusation.Because of the reservoir deep in the stratum,there are many factors affecting the filtrate of drilling fluid.Due to the limitation of enviromental conditions,an accurate invasion profile can't be obtained.And since invasion zone of drilling fluid filtrate into the formation is a time-dependent dynamic profile,the traditional step model can't meet the needs of interpretation and evaluation.Therefore,it's very important to determine the invasion profile to accurately evaluate the reservoir.This paper is based on the drilling fluid filtrate invasion mechanism.Then the Darcy's law,two-phase fluid equation and convective diffusion equation are used to construct a formation model.After that,IMPES method is applied to solve the equation.Combined with Archie's formula,the profile of formation pressure,water saturation,formation water salinity,formation water resistivity and formation resistivity at different step of invasion process are studied in detail.The effects of porosity,permeability,formation fluid viscosity and initial formation water saturation on the invasion process are studied in detail.Using the result determine formation fluid properties and invasion radius.On the basis of the model parameters at different steps,using the Doll geometry factor to simplify the array induction logging and calculate the response of the apparent resistivity curves.According to the obtained law,the actual well data was processed and analyzed.Using the well data of X in the GD area to check the correctness of the method.The PJ-102 well data lacking some parameters is calculated by using the forward simulation trial and error method,which dynamically determines the formation resistivity profile.Through the test of actual logging data,the method of dynamic evaluation of reservoirs by array induction logging can obtain the resistivity profile of the formation more accurately,and provide data for logging interpretation and reservoir evaluation.