定向滑动钻进控制系统与控制方法研究

New directional slide drilling control system and control approach

针对螺杆钻具在定向钻井过程中由于井眼摩阻大所导致的工具面调整困难和滑动钻进托压问题,利用顶驱精确定位和左右旋转的特点,研究开发基于顶驱可编程控制器(PLC)和传感器于一体的滑动钻进控制系统。本文深入研究和分析了钻具滑动前后摩擦力的变化规律和控制扭矩旋转钻具减小井眼摩阻的方法。通过5个传感器的实时数据采集,依据定向工程师的经验和推理方法,将其转换为计算机可以执行的控制程序,建立以PLC为核心的人机控制界面,PLC计算调整工具面所需的旋转角度,将工具面准确调整到设计的工具面角度;根据大钩悬重和压差?P判断托压,出现托压时PLC计算不改变工具面的旋转扭矩,以计算的扭矩为限值左右旋转钻具减小井眼摩阻,直到压差?P>0,解决滑动托压。研究表明,新方法能大幅减小井眼摩阻,提高机械钻速;其方法是目前解决螺杆钻具滑动钻进最有效的控制方法。

Using screw drill during directional drilling, due to the high drag of the wellbore, aiming at adjustment difficulty of tool face as well as off WOB problem in slide drilling, utilizing characteristics of accurate positioning and left and right rotation from top drive, a slide drilling control system based on the top drive's programmable logic controller(PLC) integrated with sensors is being researching and developing. Aiming at the variation of the friction about drill string in sliding before and after, as well as the method of reducing wellbore drag by controlling drill string rotary torque, this paper is conducted in-depth research and analysis. Through the real-time data acquisition of 5 sensors, based on the experiences and reasoning methods of directional engineers, which are converted to a set of control program being executed by the computer, a man-machine control interface with the core of PLC is to be built. The PLC calculates the rotary angle required to be adjusted the tool face and then the tool face angle is to be accurately adjusted to the design tool face angle; According to the hook weight and differential pressure to determine off WOB, if it is true, PLC calculates the rotary torque value without making the changes of the tool face angle and then the top drive rotates the drill string left and right by using calculated torque value to reduce the wellbore drag until the differential pressure is more than zero, and sliding off WOB will be solved. Study shows that the new method can significantly reduce wellbore drag and improve the ROP. The method is currently the most effective method for solving screw drill slide drilling.