碳酸盐岩储层小岩样与全直径岩心分析孔隙度关系研究

Study on Relation Between Core Analysis Porosities of Small Samples and That of Whole Diameter Samples in Carbonate Reservoirs

研究了碳酸盐岩储层小岩样岩心分析孔隙度与全直径岩心分析孔隙度关系,选用219块全直径岩心与大量小岩样岩心做了孔隙度数据分析,利用随机抽样数据拟合公式计算出由小岩样岩心分析孔隙度刻度测井解释后所需二次校正量,得出在低孔隙度段（0-17%）小岩样岩心分析孔隙度小于全直径岩心分析孔隙度,但是在孔隙度大于17%以后小岩样岩心分析孔隙度大于全直径岩心分析孔隙度,并给出了定量校正公式及图版,以及随机互不相同抽样的源程序。

The core recovery in formations with excellently growing pore Or fracture is always much less than that with poorly growing one. Logging data calibrated with the core analysis porosities derived from such an abnormal population might be apt to result in a pessimistic reservoir evaluation. Based on data of core analysis porosities from 219 pieces of whole diameter samples and data of corresponding small samples, with 10 times of random sampling, fitting relation between core analysis porosity of small sample and that of whole diameter sample in carbonate reservoir is derived. Its average trend is that core analysis porosity of small sample is less than that of whole diameter sample when porosity is less than 17%, nevertheless, core analysis porosity of small sample is greater than that of whole diameter sample when porosity is more than 17%. The secondary corrections for calibrating logging data with small core samples are calculated, the quantitative correction formula and chart, as well as source program in Excel subroutine for the random sampling are presented.