带旋转导向工具底部钻具组合的动力学特性分析及参数优化

Dynamic characteristics analysis and parameter optimization of rotary steering bottom-hole assembly

胡以宝 狄勤丰 李汉兴 王文昌 姚建林

HU Yibao DI Qinfeng LI Hanxing WANG Wenchang YAO Jianlin

上海大学，上海市应用数学和力学研究所，上海　200072 中海石油研究中心，北京　100027

Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China Research Center of CNOOC, Beijing 100027, China

带旋转导向的底部钻具组合（RSBHA）在钻井过程中发挥着极其重要的作用，现场更多关注的是其导向能力，对它的工作状态平稳性没有严格要求。为防止RSBHA的剧烈振动和失效事故，建立了RSBHA的动力学模型，运用有限元法分别计算分析了不同结构、不同转速、不同钻压条件下的底部钻具组合的动力学特性，求得了动态位移和动态弯曲应力。结果显示：合理安放稳定器能够有效地减弱RSBHA的横向振动，降低其动态弯曲应力；转速对RSBHA的动态弯曲应力影响很大，当转速为100 r/min时应力水平最低，180 r/min时应力水平最高；带旋转导向的钻具组合结构合理时，增大钻压时，其横向位移变化较小，动态弯曲应力分布比较合理。该结果为进一步研究RSBHA提供了理论依据。

The rotary steering bottom-hole assembly (RSBHA) plays an important role in drilling. Less attention has been paid on the stability of RSBHA but more on the steering function. A dynamic model for RSBHA was established to prevent the severe vibration and failure, and the finite element method was used to calculate the dynamic characteristics. Dynamic displacements and bending stress were calculated under the conditions of different structure, different rotary speed and different weight on bit. The results showed that installing a stabilizer at an appropriate location can effectively reduce lateral displacement and dynamic bending stress of the RSBHA. Furthermore, rotary speed had a great effect on the dynamic bending stress: RSBHA with given structure reached its lowest stress level at 100 r/min and its maximum stress level at 180 r/min. If the RABHA structure was appropriate, lateral displacement of the RSBHA changed a little when the weight on bit increased, and dynamic bending stress distribution of the RSBHA seemed reasonable.