煤储层孔隙度的协同模拟

Building porosity model of coalbed using collocated cokriging

利用灰分与孔隙度具有较好相关性的特点,充分利用灰分提供的信息对孔隙度进行预测.同位协同克里金方法能够协同灰分数据进行孔隙度预测,且具有很高的运算效率.沁水盆地枣园试验区煤储层灰分与孔隙度具有较好的线性关系,在对孔隙度进行预测的过程中,首先建立灰分产率的三维模型,然后采用同位协同克里金方法,以灰分产率为次变量对孔隙度进行模拟,建立三维孔隙度模型.并与未采用协同模拟的孔隙度模型进行了比较,结果表明:利用协同模拟方法能够充分利用灰分产率提供的信息,建立的孔隙度模型更好地反映了孔隙度的分布特征与非均质性.

Based on the good relationship between ash content and porosity of coal reservoirs, the porosity distribution can be predicted by using of information provided by ash content. The collocated cokriging is such a method that can simulate porosity distribution integrating ash content data with high efficiency. The analysis of 17 samples from Zaoyuan well pattern of Qinshui basin revealed that there existed a fair linear relation between ash content and porosity, and the porosity decreasing along with the increase in ash content. There are data about ash content for all 13 development wells in Zaoyuan well pattern, but only a few wells have the data about porosity of coalbed. So, firstly built 3D model of coal ash content, then adopting the coal ash content as second variable, built 3D model of porosity of coal reservoir using collocated cokriging method. Furthermore, compared the previous porosity model and the porosity model which is built using ordinary kriging. The result shows that the method of collocated cokriging is better than ordinary kriging at making use of other correlative information, and the 3D porosity model which is built u- sing collocated cokriging can characterize the distribution and heterogeneity of porosity more subtle.