煤层气水平井钻井工艺分析与技术改进研究

Drilling Process and Technology Improvement of Coalbed Methane Horizontal Wells

针对煤层气钻井效率低、成本较高等现状,基于煤层气开发原理指出U型水平井、 L型水平井、 V型水平井和羽状水平井的设计特点。通过对比分析可知,V型水平井具有较强的排采连续性、可改造性,同时成本造价低,是目前条件下最适宜的煤层气开发井型。通过增大一开井眼直径,能够有效增大水平井的渗流面积,提高水平井产量。通过在套管外增加分级箍、封隔器及盲板等加固部件,既实现了直斜段固井、煤层段不固井,又有效增强了直斜段的稳定性。

In view of the low efficiency and high cost of coalbed methane drilling, this paper pointed out the design characteristics of U-shaped horizontal wells, L-shaped horizontal wells, V-shaped horizontal wells and feathered horizontal wells based on the development principle of coalbed methane. Through comparative analysis, it can be seen that the V-shaped horizontal well is the most suitable coalbed methane development well type under the current conditions because of its strong drainage continuity,transformability and low cost. By increasing the diameter of the opening hole, the seepage area of the horizontal well can be effectively increased and the production of the horizontal well can be improved. By adding reinforcement components such as the classification hoop, packer and blind plate outside the casing, the cementing in the straight-dip section and uncementing in the coal seam section are realized, and the stability of the straight-dip section is effectively enhanced.