无限大三层越流油气藏井底压力的精确解及典型曲线

在考虑表皮效应和井筒储存的影响的条件下，采用最大有效井径的概念，建立无限三层越流油藏井底压力的动态模型。通过拉氏变换得到拉氏空间下以Bessel函数表示的井底压力和分层流量的精确解。运用Crump数值反演方法，得到实空间的解；分析了压力动态特征。该模型不但适合于表皮系数为正的情况，也适合于表皮系数为负的情形。用新模型绘制的典型曲线进行拟合，得到更加准确的结果。

EXACT SOLUTION AND TYPICAL CURVE FOR INFINITE THREE LAYERS RESERVOIR WITH CROSSFLOW

The maximum effective hole diameter mathematical model describing flow of sligh+tly compressible fluid through a three layer crossflow reservoir is solved rigorously with consideration of wellbore storage and different skin factors.The numerical computation of these solutions is made by Crump numerical inversion method and the behavior of the systems is studied as a function of various reservoir parameters. The new model is compared with the real wellbore radii model. The new model is numerically stable when the skin is positive and negative. The real wellbore radii model is numerically stable when the skin is positive. Because the curves explicitly include skin factor and other reservoir parameters, the techniques is expected to be more accurate than the real wellbore radii model. The automatic history matching technique has made it possible to accurately determine individual layer properties and wellbore parameters.