钻柱旋转滑动控制工具的研制与应用

Development and Application of Rotary Sliding Control Tool for Drill String

文章针对页岩气井长水平段定向作业时存在的井下摩阻大、托压严重等现象,一定程度上制约了水平段延伸、机械钻速提高等问题,研制了一种钻柱旋转滑动控制工具。该工具的工作原理为类似一个带开关的离合器,当井下需要滑动定向作业时,打开工具,实现工具上端钻柱由转盘控制产生旋转运动,工具下端钻柱由螺杆控制产生滑动运动,避免定向作业时由于钻柱不旋转、只能滑动钻进且部分钻柱还紧贴井壁产生较大的滑动摩擦阻力,实现定向作业时消除滑动摩擦的同时,还可以有效解决托压问题。钻柱旋转滑动控制工具利用地面开关钻井泵的方式完成工具的启动与锁定,同时建立了工具的安放位置计算方法。样机经过测试表明,结构设计合理,开关使用寿命超过200次,成功率达到100%。经过现场试验,试验井段机械钻速提高22.5%,该工具的成功研制及推广应用后将对于页岩气水平井的降阻提速产生重要意义。

In order to solve the technical problems of high friction and serious stall during directional sliding drilling which to some extent restricts the horizontal section extension and the improvement of drilling speed in horizontal section,a kind of rotary slide drilling(RSD)is developed.The tool works like a clutch with a switch.When the directional operations in sliding mode are required,the tool is opened so that the upper part of the drill string is controlled by a rotary plate and the lower part of the drill string is controlled by a PDM to produce sliding motion,thus avoiding large sliding friction resistance resulted from the non-rotation of the drill string during directional operations with only sliding drilling and part of the drill string being close to the wellbore wall,achieving eliminating sliding friction during directional operation,and also effectively solving the problem of stall.The tool starts and locks the tool by switching on and off the drilling pump on the ground,and establishes the calculation method of the tool placement position.After the test of prototype,the structure design is reasonable,the service life of the switch is more than 200 times and the success rate reaches 100%.After the field test,the ROP of the test well section is increased by 22.5%.The successful development and application of the tool will be of great significance for the drag reduction and speed increase of shale gas horizontal Wells.