一种典型曲线拟合分析新方法──无因次压力与时间比法

A New Method of Type Curve Matching-The Method of Using the Ratio Between Dimenssionless Pressure and Time

提出了一种新的适用于均质无限大油藏具有井筒储存和表皮效应影响的压力不稳定试井分析方法，即无因次压力与时间比典型曲线拟合法。该方法首先求出无因次压力pwD，然后以PwD／（tD／CD）及1－PwD／（tD／CD）为纵坐标，tD／CD为横坐标，CDe2s为参数绘制半对数及双对数图版，即PTR典型曲线，放大了早、中、晚期曲线特征，使数据拟合更精确。在已知Cs值时，只需水平移动即可实现拟合，减少了图版拟合的多解性；若不知Cs值，通过调整Cs值进行拟合分析。本方法较适合于机抽井液面恢复分析。

A new transient pressure analysis method of the well with wellbore storage and skin effect in infinite reservoir is presented in this paper,that is the matching method using the ratio of dimensionless pressure and time. Using this method,the dimensionless pressure must be got,then using pwD/(tD/CD) and 1-PwD/(tD/CD) as longitudinal axis,tD/CD as horizontal axis,CDe2s as Parameter,the semi-log and log-log type curve are got. This kind of type curve is called the PTR type curve. This kind of type curve had significant characters in early time and late time,so that it is easy to get good matching. when Cs is known,the matching is only need to move the type curve in horizontal direction,that decrease the multisolution. If Cs is unknown,Cs can be modified to get good matching.This method is suitable for pumping well.