煤层气欠平衡钻井专用旋转控制头在郑试平4H井的应用

Field test of special rotary control head in CBM well under-balanced drilling in Well ZHP4

王国荣 雷中清 成兵 魏晓东 李大彬 刘洋

WANG Guorong LEI Zhongqing CHENG Bing WEI Xiaodong LI Dabin LIU Yang

西南石油大学机电工程学院，四川成都　610500 川庆钻探国际工程公司工程技术部，四川成都　610051

College of Mechanical and Electrical Engineering, Southwest Petroleum University, Chengdu 610500, China International Engineering CO. of Chuanqing Drilling and Exploration CO., Chengdu 610051, China

为了完善煤层气欠平衡钻井国产配套设备，缩短钻井周期，降低移运成本，设计并试制了煤层气钻井专用低压小型旋转控制头，并在沁水盆地郑庄区块郑试平4 H井进行了现场试验。检验了旋转控制头与欠平衡钻井工艺的匹配性能，测试了旋转控制头的整体使用性能，证明了产品结构设计的合理性。该设备可有效密封井口环空压力，轴承组、动密封件以及润滑冷却系统在连续运转479 h情况下无任何异常状况，顺利地将钻井液导入泥浆罐。理论与现场试验结果表明：旋转控制头的结构设计合理，冷却润滑系统可以有效保护动密封件及轴承组，胶芯寿命满足现场使用要求，可进一步推广应用。

In order to prefect domestic corollary equipment of under-balanced drilling in CBM development, reduce drilling cycle and the transportation cost, we designed and manufactured a special rotary control head with low pressure and fine type for CBM reservoir drilling and conducted the field test in well ZHP4H Block Zhengzhuang Qinshui basin. Matching performance of rotary control head and under-balanced drilling technology has been examined. The rotary control head’s overall performance has been tested in field test to prove the rationality of its structural design. This device can seal the pressure of annular space effectively at the wellhead. Bearing group, dynamic seal elements, and lubrication and cooling system were still in perfect performance after 479 hours continuous operation which provide guarantees for implementing under-balanced drilling safely and lead the drilling fluid into the mud tanks smoothly. The theoretical and field experiment results show that the structural design of rotary head is reasonable, and the cooling and lubricating system could protect the dynamic seal elements and bearing group effectively. Meanwhile, the life of rubber core can satisfy the needs of field operation, so the rotary control head worth popularizing in the future.