灰色关联分析在中阶煤层气有利井区快速优选中的应用

Application of Grey Correlational Analysis in Fast Optimization of Favorable Wellblock of Medium-rank Coalbed Methane

我国的中阶煤层气资源丰富,而开发初期对于中煤阶煤层气有利井区优选评价,目前还没有成形的成熟模式。以鄂尔多斯盆地东缘某煤层气含气区块为例,根据开发阶段中阶煤产量的主要影响因素,应用灰色关联分析的方法进行有利井区评价,排序。从资源条件、赋存条件、开发条件角度出发,筛选出含气量、煤层厚度、水文地质条件、顶板保存条件、地解比、渗透率等多个评价指标,通过分析序列、无量纲化计算关联度,并综合应用地质研究认识,进行有利井区快速排序,预测先导实验区。该方法适合其他类似煤层气含气区块的有利井区优选评价。

There is rich in medium-rank coalbed methane in China.There is not any matured evaluation mode for optimizing the mediem-rank CBM wellblock at the early development stage.By taking a certain gas block in the east margin of Ordos Basin as an example,according to the main factors influencing the coal production rate at the middle development stage,the grey correlation analysis method is applied to evaluate and sort the favorable wellblock.From the aspects such as resource conditions,occurrence and development conditions,gas content,coal thickness,hydrogeological conditions,preservation conditions,ratio of formation pressure and the critical pressure and permeability,etc are selected.Favorable wellblocks are quickly sorted through the analysis of the sequence,dimensionless correlation calculation of estimate indexes and hydro-geological condition and the roof preservation condition,geological interpretation ratio and permeability.Based on the analytical sequence and dimensionless correlation calculation,the result shows that the favorable wellblocks are sorted rapidly and pilot test areas are predicted.This method is suitable for optimizing evaluation in other similar CBM gas wellblocks.