Patent ID: 6278937
Filing Date: 2001-08-21
Classification: E21B

Abstract:
A method of controlling the position of a floating rig, in which the floating rig is joined to the well head at the sea bottom by an excavation riser and the position of the floating rig can be corrected by thrusters or a combination of thrusters and a propulsion system, comprising the steps of:allowing a neural network to learn in advance the position information of the floating rig in relation to the behaving characteristics of the excavation riser; anddetecting the angles of inclination at the upper and lower ends of the excavation riser and supplying them to the neural network so as to allow the neural network to output the information on the correction of the present position of the floating rig, thereby driving the floating rig based on the information on the correction of the present position of the rig to a position where the angles of inclination at the upper and lower ends of the riser are diminished and, thus, controlling the position of the floating rig at the position where the angles of inclination at the upper and lower ends of the riser are diminished.