煤层气直井提产阶段合理压降速率的确定

Determination the reasonable pressure dropping rate of CBM vertical wells in increasing production stage

目前,煤层气直井提产阶段的排采控制主要根据排采理论结合工程经验进行定性控制,缺少基于理论的数学模型,难以对排采进行定量控制。基于试井、渗流、等温吸附等理论,结合实验室测试及结果分析,建立了提产阶段合理压降速率的数学模型,并分析模型参数对压降速率的影响及验证模型的准确性。现场排采数据分析和数学模型计算结果对比表明,根据数学模型可以对提产阶段的排采进行定量控制,为煤层气直井的现场生产提供指导。

At present,the drainage control of CBM vertical wells in an increasing production stage is mainly controlled according to the drainage theory and engineering experience for qualitative control,lack of a mathematical model based on the theory of quantitative control for drainage. A mathematical model of reasonable pressure dropping rate in increasing production stage is established based on well testing,seepage and isothermal adsorption theory,and laboratory test,and the analysis of model parameters affecting the pressure dropping rate and the accuracy of the model are performed. Scene drainage data analysis and mathematical model calculation results contrast show that the accuracy of the model provide a guidance for the CBM vertical wells of scene production.