煤层气水平井欠平衡钻井技术研究与应用

Research and Application of Under-balanced Drilling Technology in Drilling Horizontal CBM Well

煤储层具有伤害的敏感性与不可恢复性决定了在煤层气钻完井、开采过程中要坚持采取系统的保护煤层措施。通过一个直井的油管向另一水平井环空注气实现欠平衡的钻井工艺在FP1-1井中得到成功应用,实现了快速、平稳注气,有力地保护了煤层并维持了井壁稳定。本文提出了加强单井筒水平井井身结构研究的建议,在煤层气开发井中继续推广欠平衡水平井钻井技术,为实现更为经济有效的欠平衡钻井提出了新的研究方向。

Sensitivity to damags and non-recoverability of coal reservoir determines that measures should be taken to protect the system in the process of well drilling, completion and production. The under-balanced drilling technology was successfully applied in FP1-1 well by using an oil pipe in a vertical well to carry out annular air injection, so as to achieve rapid and steady injection and provide great protection of coal seams as well as stability of well wall. The paper proposes to reinforce the structure of horizontal well and to spread application of under-balanced drilling of horizontal well in development of CBM. The paper paints out the new research direction of more economical and effective under-balanced drilling.