煤储层渗透率与煤层气垂直井排采曲线关系

The relationship between the permeability of coal bed and production curve about coal-bed methane vertical wells

根据岩石弹性理论分别建立了天然裂隙面上、最大水平主应力方向上形成裂隙的极限压力模型,绘制了压裂过程主裂隙延伸轨迹示意图;根据原始渗透率与改造后渗透率的关系,结合压裂主裂隙几何形态特征,绘制了不同渗透率关系下排采过程压力传播轨迹示意图;根据煤储层原始渗透率、压裂后渗透率不同情况下压力传播轨迹的不同,得出煤层气垂直井排采的"增—减—增"、"增—减"、"增—增"和"增—减—猛增"等4种典型排采曲线.

Based on the elasticity theory of the rock, ultimate press models about the form of interstice were established in the directions of the natural fractures and the maximal horizontal stress, the sketch map about interstice extended contrail in the process of the fracture was draen. According to the relation between the original coal bed permeability and the transformed permeability, combined with fractural morphology character, the sktech maps about the pressure spread contrail in the process of the drainage in the different permeability was drew. According to the different of the pressure spread contrail on the different original permeability and the permeability after fracturing, four kinds of drainage cruve about coal bed methane vertical wells were drawn, there are ＂increasing-reduction-increasing＂, ＂increasing-reduction＂, ＂increasing-increasing＂ and ＂increasing-reduction-jump＂.