Affiliations: [a] College of Mechanical and Electronic Engineering, China University of Petroleum, Qingdao, Shandong, China | [b] Oil and Gas CAE Technology Research Centre, China University of Petroleum, Qingdao, Shandong, China | [c] College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao, Shandong, China
Correspondence:
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Corresponding author: Xiangzhen Yan, Oil and Gas CAE Technology Research Centre, China University of Petroleum, Qingdao, Shandong, China. Tel.: +86 15588983297; E-mail:yanyf163@163.com
Abstract: The applicability of the strap-down automatic vertical
drilling system with anti-deviation and well straightening features was
examined by field tests. The drill string contact-impact and its nonlinear
characteristics were studied based on Lagrange explicit algorithm and
parallel computing method. A field test was conducted by using a strap-down
automatic vertical drilling system, and the contact-impact between drill
string and borehole was analysed by using numerical method. The actual well
deviation and azimuth were obtained along with the stress of the drill
string and compared with their counterparts in the target well. Results
showed that the strap-down automatic vertical drilling system was highly
practical, and the actual well deviation and azimuth were almost similar
with the target well. Parallel computing method greatly reduced numerical
simulation time, and parallel speedup ratio increased with the increase of
parallel node numbers. Conversely, parallel efficiency decreased with the
increase of parallel node numbers. Drill string bending stress wave
propagation was the root cause of alternating stress. The lagging effect
also exists in the impact of drill string.
