现代产量递减分析Blasingame图版制作之纠错

以Blasingame方法为代表的现代产量递减分析技术是近年来油气藏工程研究的热点之一。目前国内大多数产量递减分析文献都采用Blasingame方法制作典型曲线图版并据此分析相关参数的敏感性,但很容易出现两类问题:要么在生成典型曲线图版时出现错误.要么建立了某一储层类型的Fetkovich递减分析曲线.未进一步建立Blasingame曲线,从而失去了应用价值。为此,以圆形有界均质储层为例,剖析了产生上述问题的原因;以无越流双层储层为例,明确了B1asingame方法曲线图版制作的流程;给出了圆形有界均质、双重孔隙介质、三重孔隙介质储层现代产量递减分析无因次产量的拉氏空间解及典型曲线图版。研究结果表明:在进入边界控制流阶段之后,不管储层类型如何,Blasingame图版的无因次产量曲线(q_(Dd))都是一条斜率为"-1"的调和递减曲线,无因次产量积分曲线(q_(Ddi))、无因次产量积分导数曲线(q_(Ddid))逐渐汇集在一起;只有该图版才可用于变压力、变产量以及PVT变化的生产数据分析。

A note on the Blasingame type curve plotting of production decline analysis

In recent years, advanced production decline analysis has become one of the hot topics in reservoir engineering. The Blasingame method is representative and usually used to generate such type curves, according to which the sensitivity of related parameters can be analyzed. However, there are two problems involved in this method. One is there is an error when such a type curve is generated; the other is the Fetkovich type curve is constructed for a specific reservoir without the Blasingame curve, as a result it is of no application value. In view of this, closed circle homogeneous reservoirs were taken as an example to analyze the reason why the errors are resulted. In addition, Laplace space solution and the type curve of dimensionless rate (q_Dd) was obtained for a well centered in a closed circular homogeneous, composite, two-layer, dual porosity media and the triple porosity media reservoir. In the boundary control flow period, regardless of the reservoir type, the dimensionless rate (q_Dd) of the Blasingame method is a harmonic decline curve with the slope as -1, and integral dimensionless rate (q_Ddi) and derivative of integral dimensionless rate (q_Ddid) converge gradually. Only this type of curves can be used to interpret the data with the variable rate, variable bottomhole pressure and variable PVT cases.