煤层气多分支水平井井眼轨道优化设计模型

煤储层具有低压低渗特征,致使煤层气开发困难,单井产量低;而多分支水平井能显著增﹑加井筒与煤层的接触面积,提高单井产量,缩短经济回收期。为此,提出了煤层气多分支水平井井眼轨道优化设计准则和主水平井方位的选择方法,建立了煤层侧钻水平井井眼轨道优化设计模型,并将该模型用于鄂尔多斯盆地2号和10号煤层的煤层气多分支水平井井眼轨道优化设计。结果表明,该模型实现了以较短的井眼轨道进入目标靶点,保证了分支井眼的平滑度,对煤层气钻井设计具有重要的指导意义。

Trajectory optimization design model of multi-branch horizontal well of coalbed methane

Coal reservoirs have features of low pressure and low permeability, making exploitation difficult andwell yieldlow. However, multi-branch horizontal well may increase the contact area with the coal, enhance production and shorten the economic recovery period. Hence well trajectory optimization criterion of coalbed methane (CBM) multi-branch horizontal well is presented in this paper. In addition, authors established a trajectory optimal design model of the sidetrack horizontal well and then used sequential quadratic programming method (SQP). Finally well trajectory is planed by this model based on geological data in Zhengzhuang of Shanxi Province. The results show that the model achieves optimization design of multi-branch horizontal wells of CBM and deserve somewhat consideration for guideline in the process of well design.