气体钻井MMWD随钻数据传输及试验研究

GAS DRILLING MMWD DATA TRANSMISSION AND EXPERIMENTAL RESEARCH

目前气体钻井过程中随钻测量和传输手段有限,电磁波测量和传输受地层电阻率影响,传输速率相对较低,传输深度相对有限,不适应现有气体钻井应用井段不断加深的客观需要。针对这一问题,提出了MMWD微波信号传输的理念,微波信号在钻杆内依靠钻杆内壁表面电流传输,传输速率快,不受地层电阻率影响。采用链式中继的传输原理,可以突破气体钻井过程中随钻测量和传输深度的限制,从而适应当前气体钻井轨迹监测和控制的需要,现场试验表明,研制出的微波通讯短节和井下测量短节能适应气体钻井过程中井下工况,且测得的井斜数据和实钻中电子单点测得的井斜变化趋势数据吻合,能够有效指导气体钻井过程轨迹监测与控制。它在一定程度上克服了电磁波测量技术的不足,在气体钻井中具有较强的推广应用前景。

Currently, traditional MWD( Measurement While Drilling) and transmission means are limited during gas drilling. As the measurement and transmission of electromagnetic waves are influenced by formation resistivity,the transmission rate is relatively low,and the transmission depth is limited. So,the electromagnetic wave measurement technology can not adapt to the objective demand of gas drilling with the deepening of well section. According to this problem,the concepts of MMWD( Microwave Measurement While Drilling) and microwave signal transmission were put forward. The microwave signal transmission which relies on the electricity in the inner wall of drill pipe has high transmission rate and can avoid the influence of formation resistivity. Using the principle of chain mode relay transmis-sion,the constraint in MWD and transmission depth can be breakthrough to accommodate the needs of the current gas drilling trajectory monitoring and control. Field tests showed that the developed microwave communications short section and downhole measurements short section could adapt to the downhole conditions of air drilling process. The measuring well deviation data agreed with electronic single point measurement data in actual drilling. So,the MMWD could efficiently monitor and control well trajectory for gas drilling,and overcome the shortcomings of electromagnetic wave measurement technology.