Vibration analysis of push-the-bit rotary steerable bottom hole assembly

Abstract

With the development of oil and gas fields to the deep-sea, the rotary steerable system is widely used. Downhole vibration is an important factor affecting the performance of rotary steerable system. Currently, the lack of research on vibration during operation of rotary steerable system has affected the development of deep-sea oil and gas field development technology. In this paper, the dynamic model of the push-pull rotary steerable system is established based on the similarity principle. The model includes Bit-rock interaction model, Drillstring-borehole contact model and guiding force model of rotary steerable system, the trajectory and vibration of drill bit under different guiding forces are simulated. Then, the actual drilling experiment of the full-scale Push-The-Bit Rotary Steerable System (PTB-RSS) in the horizontal section is carried out. The acceleration and speed signals of the push-pull rotary steerable system in the process of applying guiding force are collected and verified with the calculation results of the dynamic model. It is found that the vibration frequency and amplitude of the Bottom Hole Assembly (BHA) gradually increase with the increase of the guiding force of the PTB-RSS during the drilling stage, which induce high-frequency torsional vibration to a certain extent. In addition, the dynamic simulation shows that when the guiding force of the rotary steerable system is increased to a certain extent, the vibration of the BHA gradually stabilizes, but the vibration amplitude does not decrease.