煤层气井底流压生产动态研究

井底流压对煤层气的开采至关重要。在考虑煤层产水量与井底流压的耦合作用下，基于质量和能量守恒定律建立了计算井底流压的数学模型。采用压力增量迭代法，利用matlab7.11编写了求解程序，分析了排采参数相互间的关系。研究结果表明:产水量与井底流压两者的关系呈非线性关系；储层渗透率越好、煤层厚度越厚，产水量与井底流压的耦合关系会更显著些；气液两相流阶段中，高产气量不仅能降低环空中气体流动的压降损失，还利于煤层气在地面管汇的运输。 

Production dynamics of CBM bottom hole pressure

Bottom hole pressure (BHP) has a great effect on CBM production, so it's necessary for us to calculate BHP accurately during CBM production. The mathematical models of BHP calculation were developed based on mass conservation law and energy conservation law, considering the influence between water production and BHP during the flow process. Matlab7.11 was used to write solving program. And the relationship among operational parameters and their effects on deliverability were analyzed. The results show that the coupling effect between water production in coal seam and BHP make them not follow a linear relationship, especially when reservoir permeability is good and coal seam is thick. High gas production rate can not only reduce pressure drop losses in the ring, but is convenient for CBM transportation on the ground.