基于多层次模糊分析法的黔北煤田煤层气有利区优选

Optimum Selection of Coalbed Methane Favorable Area in North Guizhou Coalfield Based on Multi-level Fuzzy Analysis Method

为了对黔北煤田煤层气矿权空白区块进行有利区优选,以区内8个煤层气矿权空白区块为研究对象,选取构造复杂程度、水文地质条件、埋深、主采煤层厚度、>2 m煤层数、煤级、地质资源量、地质资源丰度、含气量、渗透率、储层压力梯度、含气饱和度、构造煤发育程度、勘察程度、可采系数等15个评价指标,采用多层次模糊分析法,构建了一个3级评价参数体系及煤层气有利区块多层次模糊数学评价模型。通过层次分析法确定各层次指标的权重和隶属度,最后依据模型计算出各规划区块的综合评价系数值。结果得出:研究区8个煤层气矿权空白区的综合评价系数值介于0.5690.821之间,其中大方县大方背斜南段煤层气区块、黔西县黔西向斜西翼南段煤层气区块2个区块综合评价系数值大于0.8,为煤层气勘探开发有利区;大方县金龙向斜理化煤层气区块、黔西县黔西向斜钟山—素朴煤层气区块、金沙县黔西向斜禹漠煤层气区块、金沙县官田向斜官田坝煤层气区块、大方县金龙向斜板桥煤层气区块等5个区块的综合评价系数值介于0.60.8之间,为煤层气勘探开发次有利区;大方县大方背斜双山—竹园煤层气区块的综合评价系数值小于0.6,为煤层气勘探开发备选区。

In order to optimize the favorable areas for the blank block of CBM mining rights in north Guizhou coalfield,it Taken 8 blank blocks of coalbed methane mining rights in the area as the research objects,15 evaluation indexes such as structural complexity,hydrogeological conditions,buried depth,thickness of main coal seams,>2m coal seams,coal grade,geological resources,abundance of geological resources,gas content,permeability,reservoir pressure gradient,gas saturation,development degree of structural coal,exploration degree and recoverable coefficient are selected,A three-level evaluation parameter system and a multi-level fuzzy mathematical evaluation model for favorable blocks of coalbed methane are constructed by using multi-level fuzzy analysis method.The weight and membership degree of each level index are determined by Analytical hierarchy process.Finally,the comprehensive evaluation coefficient of each planning block is calculated according to the model.The results show that:The comprehensive evaluation coefficient values of the eight CBM mining right blank areas in the study area are between 0.569-0.821,Among them,the comprehensive evaluation coefficient values of two blocks,the CBM block in the south section of Dafang anticline in Dafang County and the CBM block in the south section of the West Wing of Qianxi Syncline in Qianxi County,are greater than 0.8,which are favorable areas for CBM exploration and development;The comprehensive evaluation coefficient values of the five blocks are between 0.6-0.8,including the physicochemical coalbed methane block of Dafang County Jinlong syncline,the Zhongshan plain coalbed methane block of Qianxi Syncline in Qianxi County,the Yumo coalbed methane block of Jinsha County Qianxi syncline,the guantianba coalbed methane block of Jinsha County guantian syncline,and the Banqiao Coalbed methane block of Dafang County Jinlong syncline,which is a sub favorable area for coalbed methane exploration and development;The comprehensive evaluation coefficient of Shuangshan Zhuyuan coalbed methane block of Dafang anticline in Dafang County is less than 0.6,which is an alternative area for coalbed methane exploration and development.