Patent ID: 9464492
Filing Date: 2016-10-11
CPC Classification: B66C,E21B,H04N

Claim Text:
1. A system for determining a position of a downhole drill pipe relative to a wrench arrangement, and for controlling the wrench arrangement for connecting adjacent drill pipes in a downhole drill-string and comprising: an imaging means configured to capture a sequence of images of the drill-string in a region above a well bore for engagement by a wrench whilst the wrench arrangement is moved towards the drill pipe projecting from the well bore, the sequence of images includes a static position of the drill pipe and the wrench arrangement while moving; a processor operable to: analyze said captured images; and to determine therefrom, via a motion detection algorithm, position of an uppermost end of the drill pipe projecting from the well bore relative to said wrench; and filter out parts of said image sequence containing motion and to determine from remaining static parts of the image the position of the uppermost end of the drill pipe; and control means operable in response to signals from the processor to control the position of the wrench arrangement in dependence on the position of the uppermost end of said drill pipe projecting from the well bore; and for disconnecting adjacent drill pipes in the drill-string: said imaging means is configured to capture an image of a joint between connected ends of said adjacent drill pipes in a region of the drill-string above the well bore; and said processor is operable to: analyze said captured image and to determine therefrom position of an uppermost end of a lower of said drill pipes projecting from the well bore, and analyze the edge contours of said drill-string in said captured image to determine position of said joint and then to perform an edge detection algorithm on the region of said image depicting said joint to determine the uppermost end of the lower of the drill pipes.