The Researches on the Nonlinear Flow Model with Quadratic Pressure Gradient and Its Application for Double Porosity Reservoir

摘要

The nonlinear flow model with quadratic pressure gradient for the double porosityreservolr is presented. Through Vsriable substitution,the flow equation is linearized. The solution to themodel is also gained,and then the new type curves are drawn up. The characteristics of the nonlinearflow are analyzed and the theoretical errors between the linear and the nonlinear solution are obtained．so it is found that the influence of the quadratic pressure gradient is very distinct,especially forthe lowpermeability,thin bed and heavy oil reservoirs. In the end,the example match explanation of aCarboniferous well in Xinjiang oilfield is made,which shows that there are some differences in theexpianation results between the linear and the non-linear model,and the error of explanation results isvery close to the theoretical error,so the quadratic pressure gradient should not be neglected．and thatthe nonlinear percolation law is the actual flow law of oil in porous medium．and that the parametervalues of non-linear model explanation are more precise than those of linear model．so the research onthe nonlinear flow model and its application with quadratic pressure gradient should be strengthened．