随钻监测技术在气体钻井中的应用

The application of monitoring while drilling to gas drilling

气体钻井是近年来兴起的一种实用钻井技术,具有保护油气产层、提高钻速、缩短建井周期及处理井漏事故等优点,应用范围越来越广泛。与常规钻井液钻井相比,气体钻井是单向循环,使用气体作为循环介质来携带岩屑、清洗井眼,使得现有录井监测系统还不能满足气体钻井现场参数监测需要,易出现钻具失效、井下燃爆、地层出水及井壁坍塌等复杂钻井问题,影响气体钻井的安全性。基于井下燃爆理论和监测监控系统技术,开展了随钻监测基本原理研究,形成了UBD气体监测系统及分析技术;通过在多口井气体钻井现场服务,验证了气体监测系统及分析技术的合理性和实用性,为安全顺利实施气体钻井提供了有力的技术支持。

Gas drilling is a practical drilling technology arises in recent years. It had been applied to protect pay formations, increase drilling speed, decrease well construction time and deal with circulation loss. Gas drilling is one way flow and is used to take along cuttings and clean borehole with compressed air. Current logging monitoring system can＇t meet the need of gas drilling and many problems occurred compared to mud drilling, such as BHA failure, downhole burst, formation water producing and borehole wall sloughing. The paper had carried on the monitoring while drilling research based on downhole burst theory and monitoring technology so that UBD gas monitoring system and matched analysis technology were formed. Then detailed monitoring service description about the GMWD technology in many wells was provided. It is verified that the GMWD technology is reasonable and practicable and can provide a safe downhole environment for gas drilling.