Patent ID: 8684851
Filing Date: 2014-04-01
Classification: E21B

Abstract:
1. A sub tool for use with a top drive of a drilling rig, said sub tool comprising: (a) a housing having an upper end, a lower end, and a housing bore extending between an upper-end opening and a lower-end opening, and defining upper, middle, and lower intervals; (b) an upper member having an upper end, a lower end, and an upper-member bore having a cylindrical lower interval, and said upper member comprising: (c) a lower member having an upper end, a lower end, and a lower-member bore extending between the upper and lower ends of the lower member, and defining upper, middle, and lower intervals, with the upper interval of the lower-member bore having longitudinal splines matingly engageable with the splines on the lower section of the upper member; and wherein an upward-facing annular shoulder is formed at the juncture of the lower and middle intervals of the lower-member bore; and (d) an elongate stinger having an upper end, a lower end, and a cylindrical outer surface, said lower end of the stinger being sealingly and coaxially mounted to the annular shoulder on the lower member; wherein: (e) an upper portion of the lower member is disposed within and fixedly mounted to the lower interval of the housing bore such that: (f) the sub tool has: (g) the upper annular chamber is in fluid communication with the exterior of the housing; (h) the middle and lower annular chambers are in fluid communication; and (i) the sub tool includes regulator means for regulating pressure in the middle and lower annular chambers.