# US 8,464,788 B2 · Hydraulic disconnect > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,788 B2 - Document ID: US8464788B2 - Status: Granted - Kind: B2 - Application number: 12/907,334 - Filed: 2010-10-19 - Published: 2012-04-19 - Granted: 2013-06-18 - Earliest claimed: 2010-10-19 - Assignees: E. Brace Tool Inc. - Applicants: Richard A. Stanford - Inventors: Richard A. Stanford - Web page: https://patentgrep.com/patent/US8464788B2 ## CPC - E21B 17/06: Releasing-joints, e.g. safety joints - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A hydraulic disconnect comprises: a downhole housing, an uphole housing, an inner mandrel, a piston, and a lock. The inner mandrel has a latch to restrict the downhole housing from relative downhole movement. The inner mandrel is connected for transmission of torque to the downhole housing. A piston is within the inner mandrel and has a latched position, and an unlatched position. The piston has a valve seat. The lock maintains the piston in the latched position, the lock being adapted to unlock in use upon receipt by the valve seat of a disconnect valve member and a predetermined hydraulic pressure. The uphole housing has a stop for restricting the downhole housing from relative uphole movement. The inner mandrel is threaded to the uphole housing and relative rotation between the uphole and the downhole housing tightens the downhole housing between the latch and the uphole housing. ## Claims ### Claim 1 A hydraulic disconnect comprising: a downhole housing; an uphole housing; an inner mandrel at least partially disposed telescopically within the downhole housing, the inner mandrel having a latch extendable in a radially outward direction to latch against an inner shoulder of the downhole housing to restrict the downhole housing from relative downhole movement, the inner mandrel being connected for transmission of torque to the downhole housing; a piston at least partially disposed telescopically within the inner mandrel and having a latched position in which an outer surface of the piston is radially inward of the latch to maintain latching against the inner shoulder, and an unlatched position in which a groove in the outer surface is radially inward of the latch to allow radial contraction of the latch into the groove for release of the inner shoulder, the piston having a valve seat; and a lock for maintaining the piston in the latched position, the lock being adapted to unlock in use upon receipt by the valve seat of a disconnect valve member and application of a predetermined hydraulic pressure in a downhole direction against the disconnect valve member to allow the piston to move into the unlatched position; in which the uphole housing has a stop for restricting the downhole housing from relative uphole movement and the inner mandrel is threaded to the uphole housing such that relative rotation between the uphole housing and the downhole housing in use tightens the downhole housing between the latch and the uphole housing. ### Claim 2 (depends on 1) The hydraulic disconnect of claim 1 in which the latch comprises a collet. ### Claim 3 (depends on 2) The hydraulic disconnect of claim 2 in which the collet terminates in one or more collet dogs, and in which the outer surface of the piston is shaped to fit within a groove, in an inner surface of the collet, radially inward of the collet dogs. ### Claim 4 (depends on 2) The hydraulic disconnect of claim 2 in which the inner mandrel and the downhole housing comprise respective out of round convex cross-sectional profiles that mesh in use for transmission of torque. ### Claim 5 (depends on 4) The hydraulic disconnect of claim 4 in which the respective out of round convex cross-sectional profiles are matching polygons. ### Claim 6 (depends on 5) The hydraulic disconnect of claim 5 in which the matching polygons are octagons. ### Claim 7 (depends on 2) The hydraulic disconnect of claim 2 in which the lock comprises shear pins and the collet terminates in one or more collet dogs, and in which the shear pins are secured between the collet dogs and the inner mandrel. ### Claim 8 (depends on 1) The hydraulic disconnect of claim 1 in which the lock comprises one or more shear pins. ### Claim 9 (depends on 1) The hydraulic disconnect of claim 1 in which the disconnect valve member is a ball. ### Claim 10 (depends on 1) The hydraulic disconnect of claim 1 in which the inner mandrel is threaded to the uphole housing with right hand threads. ### Claim 11 A hydraulic disconnect comprising: a downhole housing; an uphole housing having an inner mandrel; the inner mandrel being at least partially disposed telescopically within the downhole housing, the inner mandrel having a latch extendable in a radially outward direction to latch against an inner shoulder of the downhole housing to restrict the downhole housing from relative downhole movement in use; a piston at least partially disposed telescopically within the inner mandrel and having a latched position in which an outer surface of the piston is radially inward of the latch to maintain latching against the inner shoulder, and an unlatched position in which a groove in the outer surface is radially inward of the latch to allow radial contraction of the latch into the groove for release of the inner shoulder, the piston having a valve seat; and a lock for maintaining the piston in the latched position, the lock being adapted to unlock in use upon receipt by the valve seat of a disconnect valve member and application of a predetermined hydraulic pressure in a downhole direction against the disconnect valve member to allow the piston to move into the unlatched position; in which the inner mandrel and the downhole housing comprise respective out-of-round convex cross-sectional profiles that mesh in use for transmission of torque. ### Claim 12 (depends on 11) The hydraulic disconnect of claim 11 in which the respective out-of-round cross-sectional profiles are matching polygons. ### Claim 13 (depends on 12) The hydraulic disconnect of claim 12 in which the matching polygons are octagons. ### Claim 14 (depends on 11) The hydraulic disconnect of claim 11 in which the respective out-of-round convex cross-sectional profiles are partly circular.