A Study on Multivariate Forecast Model of Threshold Gradient Based on Grey System Theory

It is well known that there is threshold pressure gradient in low permeability porous media. The mathematic principle of GM(1,N) for threshold pressure gradient was firstly studied. Then the actual measurement data of threshold pressure gradient during the experiment were collected, and 11 reliable data were gained. By selecting 4 factors including viscosity, permeability, density and porosity as the grey modeling forecast indicators, the multivariable forecast model of GM(1,4) for threshold pressure gradient were respectively constructed. The result calculated by use of the model shows that the precision meets the requirements of engineering and the model can be used for predicting TPG. The application of this approach can supply basic data for the development of low permeability oilfield so as to save cost and labor.