Wellhead valve removal and installation tool

• US 4,460,039 A
• Filed: 11/04/1982
• Issued: 07/17/1984
• Est. Priority Date: 11/04/1982
• Status: Expired due to Fees

• Current Assignee: Cooper Cameron Corporation (SLB)
• Original Assignee: W-K-M Wellhead Systems Incorporated
• Inventors: Knight, John W.
• Primary Examiner(s): Pate, III, William F.
• Assistant Examiner(s): Dang, Hoang C.
• Application Number:
  US06/439,082
• Time in Patent Office: 621 Days
• Field of Search: 166/85, 166/77, 166/77.5, 166/80, 166/82, 166/84, 166/86, 166/377, 166/379, 166/383, 166/386, 166/387, 254/29 R, 254/106, 254/30
• US Class Current: 166/85.4
• CPC Class Codes: E21B 33/068 having provision for introducing objects or fluids into, or removing objects from, wells cementing-heads E21B33/05
• CPC Class Codes: E21B 34/02 in well heads

Abstract

A tool (10) for the installation and removal of back pressure valves or plugs in a wellhead under pressure conditions to permit repair and replacement of wellhead outlet valves. The tool (10) comprises an elongate cylindrical housing (31, 32, 33) in which a manipulator rod (30) is slidably mounted in axial alignment therewith. The tool (10) includes a piston (55) which is sleeved about the rod (30) and adapted to be selectively clamped thereto. The manipulator rod (30) is provided at one end with a back pressure valve of plug (84) attached thereto. The tool (10) includes a fluid controls system which is connectable to an external fluid pressure source (P) or the pressure of the well itself. The fluid controls system with associated valves effects pressure balancing of the rod by well pressure and permits actuation of the piston (55) to effect insertion of the manipulator rod (30) into the well against the wellhead pressure in a series of steps utilizing fluid pressure from the external source (P) or from the well itself to drive the piston (55). The manipulator rod (30) is inserted by clamping the piston (55) to the rod (30) during the down strokes until the back pressure valve or plug (84) engages a threaded portion of the bore of the wellhead. By axial rotation of the manipulator rod (30), the back pressure valve or plug (84) is threadedly connected into the wellhead bore to shut off the well and permit the removal and replacement of wellhead valves. The manipulator rod (30) may then be removed from the wellhead by manually gripping and lifting the rod after its detachment from the plug (84), the tool housing and piston (55) or by a series of steps utilizing the pressure source (P) to repeatedly actuate the piston with selective clamping of the piston to the rod (30) during the up strokes to push the rod (30) out of the wellhead.

Claims

1. A tool adapted to operatively connect on an operating wellhead assembly for use in the removal or replacement of wellhead outlet valves under high pressure conditions, said tool comprising:

An elongate housing open at one end and having an axial bore extending from said open end substantially throughout the length of said housing, said housing having connecting means adjacent its open end for mounting on a wellhead with the axial bore of said housing in communication and substantially aligned with the bore of the wellhead;

an elongate rod mounted in the bore of said housing and adapted for axial movement therein, said rod being of such length that one end thereof extends from the open end of said housing when positioned in said housing, and adapted at said one end for removably carrying a plug means for installation in the bore of the wellhead;

a cylinder provided in a section of said housing by an enlarged portion of said housing bore;

a tubular piston member slidably mounted in said cylinder in sleeved relationship to said rod and being movable in said cylinder between an uppermost position and a lowermost position, said piston member having a reduced diameter portion at one end thereof which provides an annular chamber in said cylinder about said piston member reduced diameter portion;

a first piston packing means disposed in the bore through said piston at the upper end thereof and encompassing said rod for establishing a fluid-tight seal between said rod and said piston;

a first adjustable packing gland assembly disposed in the bore through said piston at the lower end of the reduced diameter portion thereof, said packing gland assembly including a second piston packing means disposed in encircling relation to said rod and adjustable clamping means for selectively energizing and radially expanding said second piston packing means into clamping engagement with said rod;

a second adjustable packing gland assembly disposed in the bore of said housing adjacent one end thereof, said second adjustable packing gland assembly including lower annular packing means disposed in encircling relation to said rod and a second adjustable clamping means for selectively energizing said lower annular packing means to radially expand said lower annular packing means into clamping engagement with said rod;

a bi-directional packing seal means in the bore of said housing in encircling relationship to said rod and establishing a fluid-tight sealing relationship with said rod, said bi-directional packing means being disposed in said housing bore at a location spaced from the upper end of the piston when the piston is in its uppermost position;

means for selectively communicating fluid pressure in said well bore to the bore of said housing at a location above said bi-directional packing means thereby equalizing the pressure on both ends of said rod when the tool is mounted in a wellhead and the lower end of the rod is exposed to the well pressure;

means for selectively communicating fluid pressure in said well bore to the bore of said housing and the upper end of said piston when said piston is in its uppermost position to thereby drive said piston to its lowermost position and said rod downwardly by a distance corresponding to the piston stroke when said first clamping means clamps the piston to the rod and said second clamping means is in non-clamping condition; and

means for selectively communicating fluid pressure in said well bore to said annular chamber to thereby drive the piston to its uppermost position when said second clamping means is in clamping relation to said rod and said first clamping means is in non-clamping condition, said housing having a section thereof which contains said first and second adjustable packing gland assemblies and being provided with openings through which said packing gland assemblies are accessible for adjustment.

2. A tool as described in claim 1 wherein said rod is adapted to be lowered into the wellhead by a series of piston strokes for predetermined location of said plug means, said plug means being installable in said wellhead bore upon axial rotation of said manipulator rod.

3. A tool as described in claim 1 wherein said housing openings are sufficiently large that the manipulator rod may be manually gripped for axial rotation to install or remove said plug means or may be lifted for removal from the well bore when said first and second clamping means are in non-clamping condition.

4. A tool adapted to operatively connect on an operating wellhead assembly for use in the removal or replacement of wellhead outlet valves under high pressure conditions, said tool comprising:

an elongate housing open at one end and having an axial bore extending from said open end substantially throughout the length of said housing, said housing having connecting means adjacent its open end for mounting on a wellhead with the axial bore of said housing in communication and substantial alignment with the bore of the wellhead;

an elongate manipulator rod mounted in the bore of said housing and adapted for axial movement therein, said rod being of such length as to extend from the open end of said housing when positioned in said housing and adapted at said one end for removably carrying a plug means for installation in the bore of the wellhead;

a cylinder provided in a section of said housing by an enlarged portion of said housing bore;

a tubular piston member slidably mounted in said cylinder in sleeved relationship to said rod and being movable in said cylinder between an uppermost position and a lowermost position, said piston member having a reduced diameter portion at one end thereof which provides an annular chamber in said cylinder about said piston member reduced diameter portion;

a first piston packing means disposed in the bore through said piston at the upper end thereof and encompassing said rod for establishing a fluid-tight seal between said rod and said piston;

a first manually adjustable packing gland assembly disposed in the bore through said piston at the lower end of the reduced diameter portion thereof, said packing gland assembly including a second piston packing means disposed in encircling relation to said rod and adjustable clamping means for selectively energizing and radially expanding said second piston packing means into clamping engagement with said rod;

a second manually adjustable packing gland assembly disposed in the bore of said housing adjacent one end thereof, said second adjustable packing gland assembly including lower annular packing means disposed in encircling relation to said rod and a second adjustable clamping means for selectively energizing said lower annular packing means to radially expand said lower annular packing means into clamping engagement with said rod;

a bi-directional packing seal means in the bore of said housing in encircling relationship to said rod and establishing a fluid-tight sealing relationship with said rod, said bi-directional packing means being disposed in said housing bore at a location spaced from the upper end of the piston when the piston is in its uppermost position;

means for selectively communicating fluid pressure in said well bore to the bore of said housing at a location above said bi-directional packing means thereby equalizing the pressure on both ends of said rod when the tool is mounted in a wellhead and the lower end of the rod is exposed to the well pressure;

an external source of fluid pressure;

means for selectively communicating fluid pressure from said external source of fluid pressure or from said well bore to the bore of said housing and the upper end of said piston when said piston is in its uppermost position to thereby drive said piston to its lowermost position and said rod downwardly by a distance corresponding to the piston stroke when said first clamping means clamps the piston to the rod and said second clamping means is in non-clamping condition; and

means for selectively communicating fluid pressure from said external source of fluid pressure or from said well bore to said annular chamber to thereby drive the piston to its uppermost position and said rod remaining stationary when said second clamping means is in clamping relation to said rod and said first clamping means is in non-clamping condition.

5. A tool as described in claim 4 wherein said rod is adapted to be lowered into the wellhead by a series of piston strokes for predetermined location of said plug means, said plug means being installable in said wellhead bore upon axial rotation of said manipulator rod.

6. A tool as described in claim 4 wherein said housing is provided with openings which are sufficiently large that the manipulator rod may be manually gripped for axial rotation to install or remove said plug means or may be lifted for removal from the well bore when said first and second clamping means are in non-clamping condition.

7. A tool adapted to operatively connect on an operating wellhead assembly for use in the removal or replacement of wellhead outlet valves under high pressure conditions, said tool comprising:

an elongate housing open at one end and having an axial bore extending from said open end substantially throughout the length of said housing, said housing having connecting means adjacent its open end for mounting on a wellhead with the axial bore of said housing in communication and substantially aligned with the bore of the wellhead;

an elongate rod mounted in the bore of said housing and adapted for axial movement therein, said rod being of such length that one end thereof extends from the open end of said housing when positioned in said housing and adapted at said one end for removably carrying a plug means for installation in the bore of the wellhead;

a cylinder provided in a section of said housing by an enlarged portion of said housing bore;

a tubular piston member slidably mounted in said cylinder in sleeved relationship to said rod and being movable in said cylinder between an uppermost position and a lowermost position;

a first piston packing means disposed in the bore through said piston and encompassing said rod for establishing a fluid-tight seal between said rod and said piston;

a first adjustable packing gland assembly also disposed in the bore through said piston, said packing gland assembly including a second piston packing means disposed in encircling relation to said rod and adjustable clamping means for selectively energizing and radially expanding said second piston packing means into clamping engagement with said rod;

a second adjustable packing gland assembly disposed in the bore of said housing adjacent one end thereof, said second adjustable packing gland assembly including lower annular packing means disposed in encircling relation to said rod and a second adjustable clamping means for selectively energizing said lower annular packing means to radially expand said lower annular packing means into clamping engagement with said rod;

a bi-directional packing seal means in the bore of said housing in encircling relationship to said rod and establishing a fluid-tight sealing relationship with said rod, said bi-directional packing means being disposed in said housing bore at a location spaced from the upper end of the piston when the piston is in its uppermost position;

means for selectively communicating fluid pressure in said well bore to the bore of said housing at a location above said bi-directional packing means thereby equalizing the pressure on both ends of said rod when the tool is mounted in a wellhead and the lower end of the rod is exposed to the well pressure;

fluid control means to selectively apply fluid pressure to one or the other sides of said piston for moving said piston in either direction between its uppermost and lowermost positions, said rod being movable in a series of steps by said piston in accordance with selective activation of said first and second adjustable clamping means to either lower said plug means into operating position in the wellhead bore or to retract said manipulator rod from the wellhead after installation of said plug means in the wellhead.

8. A tool as described in claim 7 wherein said rod is adapted to be lowered into the wellhead by a series of piston strokes for predetermined location of said plug means, said plug means being installable in said wellhead bore upon axial rotation of said manipulator rod.

9. A tool as described in claim 7 wherein said housing is provided with openings which are sufficiently large that the manipulator rod may be manually gripped for axial rotation to install or remove said plug means or may be lifted for removal from the well bore when said first and second clamping means are in non-clamping condition.