Hydraulic latch for capillary tubing string
AssigneeDouble-E Inc.
InventorsRobert Heinonen, John Allen
Life of this patent
Estimating the term…
Abstract
An hydraulic latch for selectively securing and, when necessary, automatically releasing capillary tubing suspended in a well bore in a manner affording clearance of a subsurface safety valve through which the suspended capillary tubing is suspended prior to release.
Claims30
A tubing latch for selectively coupling and decoupling upper and lower sections of small diameter tubing suspended within a well bore, said latch being disposed above a subsurface-safety valve through which said lower tubing section passes when coupled to said upper tubing, said tubing latch comprising:
- a housing formed of a plurality of axially aligned latch elements having an axial bore disposed therethrough for securement of said upper and lower tubing sections therein;
- an upper housing assembly adapted to secure said upper tubing section;
- first means slidably coupled into said upper housing for frictionally restraining movement of said upper tubing section;
- a lower housing assembly adapted to releasably secure said lower tubing section;
- second means slidably coupled into said lower housing for frictionally restraining movement of said lower tubing section;
- and
- mechanical-hydraulic means for urging said slidable coupling of said second means such that mechanical action secures said lower tubing section in a first mode and hydraulic action secures said lower tubing section in a second mode, and wherein said second mode of securement allows said decoupling of said lower tubing section in the event of select hydraulic depressurization to permit said lower tubing section to drop below said subsurface-safety valve.
A method of selectively coupling and decoupling upper and lower sections of small diameter tubing suspended above a subsurface-safety valve within a well bore with a tubing latch such that the lower section of tubing is suspended through said subsurface safety valve, said tubing latch comprising:
- assembling a housing from a plurality of threadably connected latch elements formed with an axial bore therethrough adapted for receipt of said upper and lower tubing sections therein;
- assembling a top plug in an upper housing assembly axially aligned with an upper section of an elongate guide containing a plurality of slips therein adapted to secure said upper tubing section therewith through the threaded engagement of said top plug and said upper section of said elongate guide therebetween;
- forming a lower housing assembly of a lower section of said elongate guide and providing, a slip piston cylinder threadably connected thereto with a slip piston reciprocally mounted therein, and a seal piston disposed within said slip piston housing and in axial engagement with said slip piston for mechanically urging said slip piston into engagement with a plurality of slips disposed thereagainst for securing said lower section of capillary tubing therein;
- forming said slip piston for urging said lower slips into engagement with said lower section of small diameter tubing by axial mechanical force from said seal piston in a first mode and by hydraulic actuation through the presence of hydraulic pressure within said slip piston cylinder in a second mode to therein allow select decoupling of said lower tubing section in the event of select hydraulic depressurization to therein permit said lower tubing section to drop below said subsurface-safety valve.
Dependencies are inferred from the claim text.