Artificial intelligence-assisted station keeping for improved drillship operations

Abstract

The rising global demand for oil has driven the offshore industry toward deep and ultra-deepwater exploration. Drillships are critical in these operations due to their high mobility and adaptability to challenging environments. Station-keeping is paramount for safe operations, as drifting beyond thresholds can result in severe economic losses and environmental disasters. This study presents a novel approach to drillship station-keeping by leveraging artificial intelligence (AI) to locally control the dynamic positioning (DP) system, thereby eliminating reliance on global positioning systems or internet-based systems. A numerical model of a drillship was developed, and simulations across multiple sea states generated a comprehensive database to train an AI controller. The system focuses on key degrees of freedom: surge, sway, and yaw. Positional changes detected by the onboard inertial navigation system are analyzed to calculate displacement, representing the vessel’s response to external forces. The trained AI matches these responses to database entries, calculates the required thrust force, and applies it through DP thrusters to restore the vessel’s position. The results showed that the AI controller achieves high precision in station-keeping across various sea states, confirming its robustness and reliability. The key novelty of this method lies in its onboard, localized control system, which enhances operational independence and safety by eliminating external dependencies while significantly reducing the risk of positional loss in ultra-deepwater environments. By combining advanced numerical simulations with AI tools, this study introduces an innovative, safer, and more efficient solution for maintaining drillship stability in demanding marine conditions.

Keywords

Artificial intelligence / Drillship / Dynamic positioning system / Inertial navigation system

Funding

None.

Declaration of competing interest

The authors declare no conflict of interest.

References

[1] Machado L do V, Fernandes AC. Moonpool dimensions and position optimization with Genetic Algorithm of a drillship in random seas. Ocean Eng. 2022; 247. http://dx.doi.org/10.1016/J.OCEANENG.2022.110561

[2] Chandrasekaran S, Phoemsapthawee S, Krishna S, Hari S. Fundamentals of Offshore Engineering. CRC Press, Florida, USA, 2024;280. ISBN: 9781032806068.

[3] Molin B. On the piston and sloshing modes in moonpools. J Fluid Mech. 2001; 430:27-50. http://dx.doi.org/10.1017/S0022112000002871

[4] Chandrasekaran S, Muthu Selvakumar N. Dynamic analysis of drillship under critical environmental loads. Presented at: International Offshore and Polar Engineering Conference; 2023:2366-2373.

[5] Chandrasekaran S, Uddin SA. Postulated failure analyses of a spread-moored semi-submersible. Innov Infrastruct Solut. 2020; 5(2):36. http://dx.doi.org/10.1007/S41062-020-0284-2

[6] Sørensen AJ, Sagatun SI, Fossen TI. Design of a dynamic positioning system using model-based control. Control Eng Pract. 1996; 4(3):359-368. http://dx.doi.org/10.1016/0967-0661(96)00013-5

[7] Sørensen AJ. A survey of dynamic positioning control systems. Annu Rev Control. 2011; 35(1):123-136. http://dx.doi.org/10.1016/J.ARCONTROL.2011.03.008

[8] Hu X, Du J, Shi J. Adaptive fuzzy controller design for dynamic positioning system of vessels. Appl Ocean Res. 2015; 53:46-53. http://dx.doi.org/10.1016/J.APOR.2015.07.005

[9] Li H, Chen H, Gao N, Aït-Ahmed N, Charpentier JF, Benbouzid M. Ship dynamic positioning control based on active disturbance rejection control. J Mar Sci Eng. 2022; 10(7):865. http://dx.doi.org/10.3390/jmse10070865

[10] Korde UA. Active heave compensation on drill ships in irregular waves. Ocean Eng. 1998; 25(7):541-561. http://dx.doi.org/10.1016/S0029-8018(97)00028-0

[11] Lee HW, Roh M Il. Review of the multi-body dynamics in the applications of ships and offshore structures. Ocean Eng. 2018; 167:65-76. http://dx.doi.org/10.1016/J.OCEANENG.2018.08.022

[12] Tomera M, Podgórski K. Control of dynamic positioning system with disturbance observer for autonomous marine surface vessels. Sensors 2021; 21(20):6723. http://dx.doi.org/10.3390/s21206723

[13] Li H, Chen H, Gao N, Aït-Ahmed N, Charpentier J-F, Benbouzid M. Ship dynamic positioning control based on active disturbance rejection control. J Mar Sci Eng. 2022; 10(7):865. http://dx.doi.org/10.3390/jmse10070865

[14] Ma KT, Luo Y, Kwan T, Wu Y. Detailed design and construction of dp drillships for deepwater; 2018. http://dx.doi.org/10.1016/C2018-0-02217-3

[15] Chandrasekaran S, Jain AK, Shafiq N, Mubarak MA, Wahab A. Design aids for offshore platforms under special loads. CRC Press, Florida; 2021:280, ISBN: 9781032136844.