SEC储量动态评估方法在煤层气田中的应用——以鄂尔多斯盆地韩城区块为例

Application of SEC dynamic reserves evaluation method in coalbed methane field:A case from Hancheng block in Ordos basin

目前,煤层气田的SEC储量评估均采用动态评估法,在评估过程中存在参数取值多样化、计算结果不一致等问题,为了解决这个问题,以鄂尔多斯盆地韩城区块为例,综合运用一系列与煤层气的生产特点相适应的评估方法,优化各种参数,总结递减规律。研究结果表明:根据构造和地质条件划分地质单元,在此基础上按照开发效果划分评估单元能够客观合理地分析煤层气田的递减规律;综合运用指数递减、双曲递减、调和递减等动态储量递减方法建立典型曲线,可以用来检验储量评估结果的合理性;对于一个单元进行储量评估过程中,递减率的取值要充分考虑后期增产措施的影响。

At present,all the SEC reserves evaluation of coalbed methane fields uses dynamic assessment methods.In the process of evaluation,the parameters and calculation results are various.In order to solve this problem,this paper takes the Hancheng block in Ordos basin as an example,a series of evaluation methods adapted to the pro-duction characteristics of coalbed methane have been comprehensively applied,optimizing various parameters,and summarizing the law of decline.The results show that geological units are divided according to tectonic conditions,and on this basis,evaluation units are divided according to development effect,which can objectively and reasona-bly analyze the law of coalbed methane field decline.A typical curve of dynamic reserves reduction,such as expo-nential decline,hyperbolic decline and harmonic decline,can be used to test the reasonableness of the results of reserves evaluation.For an evaluation unit,in the process of reserve evaluation,the effect of late production in-crease measures should be taken into full consideration when the value of decline rate is taken into account.