应用孔喉体积—渗透率贡献分布曲线确定流动孔喉半径下限值

DETERMINATION OF CUT-OFF VALUE OF EFFECTIVE THROAT RADIA BY PERMEABILITY -CONTRIBUTION CURVE

我国非均质性强、低孔隙度、低渗透率油气层,确定其流动孔喉半径下限值十分困难。我们对吐哈盆地丘陵油田J_2s油层的研究,找到了一种既方便又简单的新方法,用孔喉体积—渗透率贡献分布曲线可以较准确地确定这类油层流动孔喉半径下限值。本文介绍了该方法的理论基础,求值过程和准确性检验,该方法求得的油气层流动孔喉半径下限值及其它相应的参数,在油气层定量评价中,获得了较满意的效果。

The reservoirs in most continental basins in China are of relatively intensive heterogeneity, commonly of low porosity and low permeability. It is very difficult and complicated to determine the cut-off value of effective throat radia for such reservoirs by conventional methods. Based on our study of the reservoirs of J_2S formation in Tu-Ha basin, we propose here a new simple and easy method, by which the cut-off value of effective throat radia for reservoirs with characters mentioned above is accurately determined from the pore-throat volume versus permeability-contribution curve, and present the theoretical basis, the calculation procedure and the accuracy check of the method. The result obtained by this method is satisfactory in quantitative evaluation of reservoirs.