变表皮系数在气井试井解释中的应用

在气井试井解释中,使用固定的表皮系数来进行压力全历史拟合,很难将压力历史曲线拟合好,而且不尽合理。气体的高速流动,导致气井附加的压力降。流量越大,表皮系数越大。基于叠加原理,以及变表皮系数的理论,通过实例分析,对气井不稳定试井进行压力全历史拟合,获得了很好的拟合效果。通过拟合获得的各流动段表皮系数,由线性回归得到真表皮系数。

The use of changing-skin factors on gas well-testing interpreting

In gas well-testing interpreting, it is difficult and unreasonable to match pressure-history curve by using unchanged skin. Gas high speed flowing rate leads to the gas well additional pressure drop and additional skin. The more the flow rate is, the more skins are. Based on superposition and changing-skin theory, pressure whole history matching in unstable welt-testing has been carried using true extra,pie. And good matching is acquired. Using skin acquired by matching on different flowing period, we can acquire true-skin through line regression.