Patent ID: 9322226
Filing Date: 2016-04-26
CPC Classification: E21B

Claim Text:
1. A system for attaching a pipe string on a floating installation, the system comprising: a heave compensator; a heave-compensated load bearing unit comprising a top drive that is connected to the heave compensator; and a release module device comprising at least two suspension stays interconnected via a pipe clamp, wherein each suspension stay is constituted of a hydraulic cylinder unit forming an extendable connection between the top drive and a portion of the pipe string, and each of the hydraulic cylinder units is connected in a fluid communicating manner to an accumulator unit via a hydraulic fluid circuit, each of the hydraulic cylinder units having an upwardly facing cylinder end pivotally connected to the top drive, and a downwardly facing cylinder end opposite the upwardly facing cylinder end, wherein the hydraulic fluid circuit comprises a safety valve arrangement configured to be reactive and responsive according to predetermined set hydraulic fluid limits and to hydraulic fluid pressure within each of the hydraulic cylinder units upon failure of the heave compensator to permit or prevent fluid communication between each of the hydraulic cylinder units and the accumulator unit, and wherein an overloading of the pipe string due to failure of the heave compensator causes the safety valve arrangement to reduce or increase working pressure of each of the hydraulic cylinder units so that the top drive, following heave motion of the floating installation upon failure of the heave compensator, is moved relative to the pipe string which remains stationary as long as heave motion is within a stroke of each of the hydraulic cylinder units.