Research on Lateral Vibration Characteristics of Bottom Hole Assembly with Rotary Steerable Tool
(2.School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444)
【Abstract】To improve the wellbore trajectory control effect and operation safety of rotary steerable tools, this paper analyzed the lateral vibration characteristics of a bottom hole assembly with a static push-the-bit rotary steerable tool (RSBHA). The static push-the-bit rotary steerable tool can control borehole trajectories through the driving force produced from its three steering pads, and thus it can be regarded as an eccentric stabilizer with known eccentricity and eccentric azimuth. In this work, a three-dimensional static model of an RSBHA with small deflection was constructed to determine the spatial configuration of an RSBHA under the weight on bit and the constraints of the borehole wall by the weighted residual method and thereby obtain the upper tangent point. Then, a finite-element model was built, with the distance between the upper tangent point and the bit as the effective length for lateral vibration. The lateral vibration responses of the RSBHA could be elicited using the vibration mode superposition method, and analysis of the influences of working and structural parameters on its lateral vibration could be made. The calculation results showed that when the rotary speed was around 138 r/min, the dynamic displacement of the RSBHA was greater at distances of 8.20 m, 18.10 m, 24.60 m, and 31.60 m away from the bit. The weight on bit had little impact on the maximum bending stress in the RSBHA, while eccentricity and eccentric azimuth had a greater impact on the lateral vibration characteristics of the RSBHA, and the maximum bending stress would obviously increase under certain eccentricity and eccentric azimuth. The research shows that working and structural parameters have great influences on the lateral vibration of the RSBHA and therefore should be optimized to ensure the proper application and operation safety of rotary steerable tools.
【Keywords】 rotary steerable tool; bottom hole assembly (BHA); lateral vibration; modal analysis; parameter optimization;
(Translated by XIA CJ)
 WANG Zhirui, WANG Junliang. Development of rotary steering technology in foreign countries and its status quo in China [J]. Drilling & Production Technology, 2018, 41 (2): 37–41 (in Chinese).
 ZHENG Fenghui, HAN Laiju, YANG Li, et al. Development of novel drilling technology [J]. Petroleum Drilling Techniques, 2008, 36 (4): 5–11 (in Chinese).
 DI Qinfeng. Rotary closed-loop drilling technology [M]. Xi’an: Shaanxi Science & Technology Press, 1999 (in Chinese).
 LI Gensheng, SONG Xianzhi, TIAN Shouceng. Intelligent drilling technology research status and development trends [J]. Petroleum Drilling Techniques, 2020, 48 (1): 1–8 (in Chinese).
 DI Qinfeng, ZHAO Yerong. The establishing of dynamics equations and the transfer functions of the steering assembly of the downhole closed-loop drilling system [J]. Acta Petrolei Sinica, 2000,21 (4): 87–92 (in Chinese).
 LI Jun, LI Dongchun, ZHANG Hui, et al. The influencing factors of the inclination ability of push-the-bit rotary guiding tool [J]. Oil Drilling & Production Technology, 2019, 41 (4): 460–466 (in Chinese).
 LIU Jianhua, SI Jieru, GENG Yanfeng, et al. Design and performance analysis of the measurement and control systems of the dynamic point-the-bit rotary steerable drilling tool [J]. Petroleum Drilling Techniques, 2018, 46 (6): 59–64 (in Chinese).
 XU Tianwen, YANG Feng, ZHAO Jianguo. Analysis on the field application of AutoTrack rotary steering tool [J]. West-China Exploration Engineering, 2016, 28 (6): 11–13 (in Chinese).
 SHI Yucai, TENG Zhixiang, BAI Jing, et al. Improved mechanical model of the static push-the-bit rotary steerable bottom-hole assembly [J]. Journal of China University of Petroleum (Edition of Natural Science), 2018, 42 (5): 75–80 (in Chinese).
 WANG Mingjie, DI Qinfeng, WANG Wenchang, et al. Affection of flex sub’s position and length on the steering force of RSBHA [J]. Drilling & Production Technology, 2012, 35 (1): 52–55 (in Chinese).
 WANG Heng, GUAN Zhichuan, SHI Yucai, et al. Effects of flex sub on build-up performance of push-the-bit RSBHA [J]. Drilling & Production Technology, 2018, 41 (6): 19–22 (in Chinese).
 PENG Yong, YAN Wenhui, LI Jibo. The optimal design of the steering force for the rotary steerable drilling Tool [J]. Petroleum Drilling Techniques, 2006, 34 (2): 10–14 (in Chinese).
 DI Qinfeng, WANG Mingjie, HU Yibao, et al. Effect of flex sub’s position on Bottom hole assembly with rotary steering tool [J]. Journal of China University of Petroleum (Edition of Natural Science), 2012, 36 (5): 84–88 (in Chinese).
 Burgess T M, McDaniel G L, Das P K. Improving BHA tool reliability with drill string vibration models: field experience and limitations [C]//SPE/IADC drilling conference. OnePetro, 1987.
 DYKSTRA M W. Nonlinear drill string dynamics [D]. Tulsa: The University of Tulsa, 1996.
 ZHANG He, DI Qinfeng, QIN Guangxu, et al. Quick solution method for lateral vibration response of Pre-bent bottom-hole assembly [J]. Acta Petrolei Sinica, 2017, 38 (12): 1441–1447 (in Chinese).
 LI Zifeng. Tubular mechanics in oil-gas wells and its applications [M]. Beijing: Petroleum Industry Press, 2008: 133–140 (in Chinese).
 DI Qinfeng, ZHOU Fengqi, ZHAO Yerong. Analysis of mechanical features for low drill assembly with controllable eccentric stabilizer [J]. Oil Drilling & Production Technology, 1999, 21 (4): 7–11,113 (in Chinese).
 LI Maosheng, YAN Xiangzhen, GAO Deli. Influence of drilling fluid on natural frequency of drill string lateral vibration [J]. Journal of the University of Petroleum, China (Edition of Natural Science), 2004, 28 (6): 68–71 (in Chinese).
 KHULIEF Y A, Al-SULAIMAN F A, BASHMAL S. Vibration analysis of drillstrings with self-excited stick-slip oscillations [J]. Journal of Sound and Vibration, 2007, 299 (3): 540–558.
 CAUGHEY T K, O’KELLY M E J. Classical normal modes in damped linear dynamic systems [J]. Journal of Applied Mechanics, 1965, 32 (3): 583–588.
 Spanos P D, Payne M L. Advances in dynamic bottom hole assembly modeling and dynamic response determination [C]//IADC/SPE Drilling Conference. OnePetro, 1992.