Definition - What does Dynamic Positioning mean?
Dynamic Positioning is the stationing of vessels at a particular location in sea by using computer-controlled propulsion units known as thrusters. The wells have distinct weather and sea design conditions and most of them remain at relatively stable conditions even under the high waves, currents and wind loading conditions. The failure of one or more than one electromechanical system or enormous natural forces results in the drive off condition, which requires emergency applications for disconnecting risers from subsea BOP stack and lowering them from the vessel. The offshore vessels which mostly use this technique are semisubmersible drilling rigs and drillships.
Petropedia explains Dynamic Positioning
A computer-controlled system is used for maintaining the position and heading of the vessel automatically by using thrusters and propellers. The system consists of information related to current and wind drag of the vessel and location of thrusters. With the help of this information and the sensor information, the computer system calculates the required thruster output and steering angle for each thruster. This allows various operations at the sea where the anchoring and mooring operations are not achievable due to the congestion on the bottom of the sea, deep water or numerous other problems. It can be absolute where the position is locked to a fixed point or analogous when locked to a moving object such as underwater vehicle or another ship.