低渗透率油层试井解释新方法的研究

A NEW METHOD FOR INTERPRETING DATA FROM WELL TESTING IN LOW PERMEABILITY RESERVOIRS

本文利用单井油层的模拟程序,计算出无因次压力恢复值P_(SD)和无因次井壁产量Q_(FD)的理论数值。通过数学方法分析发现,在压力恢复曲线的早期段(包括纯井筒储集阶段和大部分过渡段)中,P_(SD)和Q_(FD)之间存在线性关系,且直线段斜率m~*和无因次生产时问(t_P)_D、无因次井筒储集系数C_D无关。因此,经过数学处理获得了压力恢复曲线早期段的新的解释方法,实例分析表明,这一解释方法是可靠而有效的。

The theoretical values of dimensioness buildup pressure P_(SD) and dimensionlesssandfacc flow rate Q_(FD) are calculated by using a program of single-well reservoirsimulation. It is found by mathematical, analysis that there is a linear relationship between P_(SD) and Q_(FD) of pressure buildup curve(including the pure wellbore storage stageand most of the transition stage)at the early-time stage. Moreover, the slop m~* of thelinear section is dependent On the dimensionless production time (t_p)_D and dimensionnesscoefficient C_D of wellbore storage. A new method for interpreting early-time pressurebuildup curves drawn via the data from well testing is developed. The resuits of applicationof this method in the field show that it is reliable and efficient.