A novel cylinder lifting system design and simulation with integrated drill pillar compensation function

Abstract

Offshore drilling rigs equipped with cylinder lifting systems have been increasingly adopted in newly constructed drilling vessels, offering significant advantages over traditional winch-based lifting systems. These advantages include improved control over the ship's center of gravity, reduced installed power requirements, enhanced maintainability, and greater energy efficiency. In this study, the feasibility and performance of the drilling string compensation function provided by the new cylinder lifting system are investigated. The mechanism underlying the drilling string compensation function is analyzed, and the longitudinal vibration characteristics of the drilling string are examined during offshore deep-hole drilling operations. To further assess the system's capabilities, a detailed simulation model of the drilling string compensation function is developed using the AMESim software platform. This model allows for the evaluation of the system's performance under varying operating conditions and different drilling depths. The results demonstrate that the cylinder lifting system is capable of achieving both passive and semi-active compensation of the drilling string. Notably, the system can effectively control compensation load and mitigate fluctuations in bottomhole pressure, thereby meeting operational requirements. While operating conditions have a greater impact on passive compensation, the introduction of semi-active compensation significantly reduces the influence of these conditions, ensuring more stable and efficient drilling operations.