Abstract
From the background information supplied by the inventors, news correspondents o btained the following quote: “Subterranean operations often include tripping seg mented tubular strings into and out of a wellbore. Wellbores can extend several thousand meters into a subterranean formation to reach reservoirs of hydrocarbon fluids. Tripping of the tubular string into and out of the wellbore can require holding the tubular string via a retention feature in a drill floor such that t he weight of the tubular string is held by the retention feature while a tubular segment is being connected to the tubular string or removed from the tubular st ring. The retention feature can include a plurality of grippers, each with an en gagement surface that engages the tubular string when the retention feature is a ctivated, such that the grippers hold the tubular string suspended from the rete ntion feature. The engagement surfaces are disengaged from the tubular string to allow axial movement of the tubular string in the wellbore, such as when the tu bular string is connected to a top drive.
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