基于熵权模糊综合评价模型的多层叠置含煤层气系统合层排采水源判别

Distinguishing Study on Commingled Drainage Water of Superimposed CBM System Based on Entropy Weight Fuzzy Comprehensive Evaluation

结合熵权理论和模糊综合评价方法,建立多层叠置含煤层气系统合层排采水源识别的熵权模糊综合评价模型,判识合层排采过程中含气系统间流体相互干扰程度。研究表明:在煤层气井合层排采过程中,中部含水系统具有较高的储层压力,先排水降压,抑制了上部含水系统储层水的产出;随着中部含水系统储层压力不断下降,上部含水系统储层压力随之下降,使得该含水系统储层水自井口流出。对多层叠置含煤层气系统合层排采过程中的动态进行诊断,结果与实际排采情况一致,为有效控制含气系统间干扰,制定科学合理的有序开采方案提供可靠依据。

Based on entropy weight theory and fuzzy comprehensive evaluation method,a entropy weight fuzzy comprehensive evaluation model for water source identification of coalbed methane drainage in multi-layer superimposed coalbed methane system is established to identify the degree of fluid interaction between gas-bearing systems in the process of production. Research shows that central aquifer system with high reservoir pressure drain away water and reduced pressure preferentially,concurrently it inhibits the upper aquifer system of reservoir water output. With reservoir pressure of central aquifer system declining, the lower reservoir pressure of the upper water-bearing system makes the reservoir water flow out. The dynamics of multi-layer stacked coalbed methane system in the process of coalbed drainage are consistent with the actual situation, which is of great significance to control the interference between gas bearing systems and develop a scientific and reasonable orderly mining effectively.