Multi-parameter Appraisal Method for the JS_2~1 Reservoir of Xinchang Gas Field

An integrated method using a multi-parameter approach is used to evaluate the reservoir of Shaximiao formation(JS~~1__2) in Xinchang Gas Field of west Sichuan.The multi-parameter method utilizes the parameters of the reservoir,the fracture,and the reservoir thickness classification.First,the reservoir and fracture parameters are calculated.Based on the result of core analysis,computation models are established for porosity,permeability and water saturation.Using cast slice to identify micro-fracture and to correlate the logging value with the fracture parameters from the sample analysis,a mathematic model is built to calculate fracture parameters from logging data.Then the cluster analysis of the reservoir is performed.The analysis clusters the reservoir into three types.Lastly,we normalize the fracture parameter,thickness,porosity,permeability and saturation of class-I reservoir.These parameters are fitted with the productivity tested to establish a multi-regression model as the mathematic model of gas bearing compositional index.Based mainly on the index,we perform the integrated classification and evaluation of the reservoir.The developed multi-parameter method proposes promising gas bearing zones and some senile wells to be instillings new life.This method has successfully guided the development of gas reservoirs.