应用于螺杆钻具的轴向振动冲击装置研制

基于推力轴承滚动体在特制起伏轨道上滚动产生轴向振动的特性，研制了一种轴向振动冲击装置，通过与螺杆马达集成使用，具有旋冲钻井和螺杆+转盘双驱复合钻井的技术优点。装置的推力轴承结构由滚轮、滚轮支架和滚轮轨道组成，该结构分整个钻柱为轴向振动冲击部分和受冲击部分；滚轮轨道上端面均布凸轮齿（齿高9~17 mm），滚轮沿凸轮齿上升面滚动时，抬升钻柱振动冲击部分蓄能；滚轮沿凸轮齿下降时，振动冲击部分钻柱在钻压和自重作用下，由螺杆输出轴与冲击传动轴在接触面上产生冲击，两轴端面间距为冲程（比凸轮齿高度小4 mm）。以3 000 m中深井应用为基本条件，采用弹性杆模拟钻柱的方法，分析了装置冲击功和蓄能扭矩与钻压及冲程的关系，给出了冲程和钻压的取值范围，据此试制的样机，在冲击性能测试中，冲击力峰值达到钻压的2.2倍，在钻压20 kN，泵排量30 L/s条件下，装置寿命达到80 h。轴向冲击装置的研制达到了设计要求，初步具备工程应用的条件。

Development of axial vibration impact device used for screw drill

Axial vibration will occur when a rolling element of thrust bearing rolls on a purpose-built relief track.Based on this property, a kind of axial vibration impact device was developed in this paper.When it is integrated with a screw motor, the technical characteristics of rotary percussion drilling and screw drill + double-table-drive composite drilling are presented.Its thrust bearing is structurally composed of roller, roller bracket and roller track, and this structure divides the whole drilling string into two parts, i.e., axial vibration impact and part and target part.Cam teeth (tooth height 9-17 mm) are distributed uniformly on the upper end face of roller track.When a roller rolls along the ascending surfaces of cam teeth, energy is stored at the vibration impact areas of ascending string.When the roller falls along cam teeth, impact is generated at the contact surface by the vibration impact area of drilling string via a screw output shaft and an impact drive shaft due to the effect of weight on bit and its self-weight, and the spacing between two end faces of shaft is defined as the stroke (4 mm shorter than the height of cam tooth).Based on the basic application conditions of 3 000 m mid-deep wells, the relationships of the impact power and energy storage torque of the device vs.weight on bit and stroke were analyzed by simulating drilling strings with elastic beams, and the ranges of stroke and weight on bit were provided.And accordingly, a prototype was experimentally developed and its impact property was tested.It is shown that when the peak impact is 2.2 times the weight on bit, the service life of this device can reach 80 h in the conditions of weight on bit of 20 kN and pumping rate of 30 L/s.It is indicated that the development of this axial impact device meets the design requirements and preliminarily satisfies the engineering application conditions.