煤层气双分支U型井合层排采特征研究

CBM Bi-lateral U-shaped Well Multilayer Drainage Features

为研究煤层气双分支U型井合层排采特征,以保德地区双分支U型井组8#和11#煤地质和储层资料为基础,依据合采对策图版分析8#煤和11#煤适合合采,以8#煤和11#煤单采、合采历史数据和排采曲线为基础,进行了排采阶段划分和排采特征分析,通过拟合分析合层排采的关键参数,结果表明:产气流入动态曲线呈现“三段直线式”特征;产水流入动态曲线呈现短期的“四段折线式”或长期的“单段折线式”特征;日产气量与排水量之间呈现“两段直线式”特征;日产气量/累计产气量与排采时间呈E指数相关。

To study CBM bilateral U-shaped well multilayer drainage features based on coal geological and reservoir data from bilateral U-shaped well group coal Nos.8 and 11 in the Baode area,according to multilayer drainage countermeasures plate,coal Nos.8 and 11 are propitious to multilayer drainage.On the basis of coal Nos.8 and 11 monolayer drainage and bi-layer drainage historic data and drainage curves carried out drainage stage partitioning and features analysis obtained multilayer drainage key parameters through fitting analysis.The result has shown that the gas inflow dynamic curve presents“tri-segment linear”features;water inflow dynamic curve presents short-term“quadru-segment polygonal line”or long-term“mono-segment polygonal line”features.Between daily gas output and water discharge presents“bi-segment linear”features.Daily gas output/cumulative gas and drainage time present E exponential dependence.