黔西滇东区块储层物性制约下煤层气开发潜力评价

Evaluation on development potential of coalbed methane under physical property restriction of reservoir in West Guizhou and East Yunnan Block

为研究煤储层物性对煤层气的可采性及开发潜力的影响,通过对黔西滇东的土城、恩洪、老厂3个区块煤储层物性的研究,阐明了这些区块煤储层物性方面的差异,并运用层次分析-模糊数学综合评判法划分了开发潜力评价等级。研究结果表明:该3个区块的可采煤层数及可采煤厚较为接近,煤层含气量层域分布规律较为复杂,煤储层渗透率普遍较低,属于特低渗~中渗储层。土城区块煤层处于超压状态,煤体结构最为完整;恩洪区块普遍欠压,煤体结构较完整,老厂区块属欠压~超压状态,煤体结构相对较为破碎。煤层气开发潜力评价等级为土城区块最有利,恩洪区块为较有利,老厂区块一般。

In order to study the physical property of the coal reservoir affected to the mineability and the development potential of the coalbed methane,with the study on the physical property of the coal reservoirs in Tucheng,Enhong and Laocheng blocks of West Guizhou and East Yunnan,the paper illustrated the differences on the physical property of the coal reservoirs in the study area. The analytic hierarchy process-fuzzy mathematics comprehensive evaluation method was applied to divide the evaluation grade of the development potential. The results showed that the number of mineable seams and mineable seam thickness in the three blocks were closed to each other,the layer distribution law of coalbed methane content was quite complicated,the permeability of the coal reservoir was generally low and was a ultra low permeable-medium permeable reservoir. The seams in Tucheng Block were in an overpressure state and the coal structure was mostly completed. Enhong Block was under pressure generally and the coal structure was quite completed. Laochang Block was in a under pressure-overpressure state and the coal structure was quite broken. The evaluation grade of the coalbed methane development potential in Tucheng Block was most favorable,Enhong Block was quite favorable and Laochang Block was general.