摇摆旋转钻具解决定向钻井托压难题

Rocking drillstring technique to solve directional drilling back pressure problem

定向钻井过程中,滑动钻进托压、马达工具面调整和保持困难,始终是影响滑动钻进机械钻速的主要问题。为了解决这些问题,一种新的基于顶驱的控制系统已完成室内试验。该系统配有一个可编程控制器,接收控制顶驱所需的MWD、钻杆扭矩、立管压力、大钩悬重等多个传感器数据。依据定向钻井控制流程,对顶驱进行程控编程,控制顶驱精确转动调整和保持工具面;运用扭矩摇摆技术顺时针逆时针交替旋转钻具,降低井眼摩阻,解决滑动托压,提高机械钻速。类似的控制系统应用证明,该系统用于滑动钻进非常有效,能显著提高造斜段和水平段的钻进能力,适用于难度较大的定向井和水平井的钻井作业。

Rate of penetrationhas always been affected due to back pressure,adjustment and maintenance of tool face angle of mud motor encounteredduring slide drilling.In order to solve these problems,an indoor test of a new control system based on top drive has been completed.A programmable Logic Controller(PLC)is set up inside the system which canreceivedatum coming from multiple sensors such as MWD,torque of drill pipe,pump pressure,hook load and so on needed for control top drive.Based on the control process of directional drilling,top drive is programmed to achieve the control goalsofaccuratelyadjusting and maintaining tool face angle and reducing the wellbore friction by applying torque rocking technology which can achievealternate rotation of drill string at clockwise and counterclockwise,thereby the problem of back pressure can be solved and penetration rate can be improved during slide drilling.The application results of similar control system has been shown that this kind of control system is very effective and available for directional drilling and can obviously enhance drilling capability in curve and lateral section,and is applicable for drilling high challenge of directional and horizontal well.