US3845816A

US3845816A - Compression packer

Info

Publication number: US3845816A
Application number: US00381647A
Authority: US
Inventors: C Pitts
Original assignee: Dow Chemical Co
Current assignee: Schlumberger Technology Corp
Priority date: 1973-07-23
Filing date: 1973-07-23
Publication date: 1974-11-05
Anticipated expiration: 1991-11-05
Also published as: CA993353A

Abstract

The invention is a compression (set down) packer with a slip type hold down actuated by hydraulic pressure from below the packing elements. The packer is full opening and will permit through-tubing operations. Once the packer''s downward movement is stopped and the packer elements expanded by conventional means including J-slot pin means for preventing unwanted expanding of the lower slips, pressure from below the packer (applied through the tubing to which the packer is attached) forces a piston and, usually, at least one booster piston upwardly to move a slip cone under the tapered surface of the upper slips to cause them to bear against the wall surface, usually the casing of the well. This outward movement of the slips stops upward movement of the packer device. Because a vacuum is created when the piston advances under pressure, once hydraulic pressure is released (or greatly reduced), the piston and slip cone retracts to relieve the vacuum condition. Subsequently, placing tension on the tubing releases the lower slips and the packer may be withdrawn from the well.

Description

United States Patent 1 Pitts [451 Nov. 5, 1974 COMPRESSION PACKER [75] Inventor: Charles A. Pitts, Wichita Falls, Tex.

[73] Assignee: The Dow Chemical Company,

Midland, Mich.

221 Filed: July 23,1973

21 Appl. No.: 381,647

[52] US. Cl. 166/120, 166/134 [51] Int. Cl E21b 23/06 [58] Field of Search 166/120, 134

[56] References Cited UNITED STATES PATENTS 3,094,169 6/1963 Conrad 166/134 3,399,729 .9/1968 McGill 1 t 166/120 3,426,846 2/1969 Young 166/120 X 3,586,106 6/1971 Conrad 166/120 2/1972 McGill .1 166/120 Primary ExaminerDavid H. Brown Attorney, Agent, or Firm-Earl D. Ayers [57] ABSTRACT The invention is a compression (set down) packer with a slip type hold down actuated by hydraulic pressure from below the packing elements. The packer is full opening and will permit through-tubing operations.

Once the packers downward movement is stopped and the packer elements expanded by conventional means including J-slot pin means for preventing unwanted expanding of the lower slips, pressure from below the packer (applied through the tubing to which the packer is attached) forces a piston and, usually, at least one booster piston upwardly to move a slip cone under the tapered surface of the upper slips to cause them to bear against the wall surface, usually the casing of the well. This outward movement of the slips stops upward movement of the packer device.

Because a vacuum is created when the piston advances under pressure, once hydraulic pressure is released (or greatly reduced), the piston and slip cone retracts to relieve the vacuum condition.

Subsequently, placing tension on the tubing releases the lower slips and the packer may be withdrawn from the well.

5 Claims, 2 Drawing Figures Pmmmuuv 5 m4 SHEET 1 (I? 2 l COMPRESSION PACKER BACKGROUND OF THE INVENTION OBJECTS OF THE INVENTION pression packer assembly.

STATEMENT OF INVENTION In accordance with this invention, there is provided a compression packer apparatus comprising an elongated tubular inner mandrel joined at one end to an upper connector member and at the other end to a lower connection member.

Outside the mandrel at the lower part of the apparatus isa lower slip assembly of known design operated by relative movement between the drag block part of the assembly and the mandrel, the mandrel controlling the movement of the lower slip cone which controls expansion of the slips. A sleeve-like member coupled to the lower slip cage has a J-slot in it into which a boss on the lower connection extends. Thus, until rotation of the mandrel (and thus rotationof the boss to put it in the long part of the .l-slot occurs, there is no relative movement between the lower slip cone and the slips.

As the mandrel is lowered to move the lower slip cone downwardly, the packing elements, disposed just above the slip cone and around a slidable sleeve, are expanded to seal against the well bore wall, usually the well casing.

An upper slip assembly is fixedly coupled to the upper connector member around the mandrel and is surrounded by a cage sleeve which extends down-.

wardly past the slip elements of the assembly.

Above the packer seal elements and below the slip elements of the upper slip assembly is disposed an upper slip cone and its hydraulic actuating means. The actuating means is a booster piston and a drive piston coupled to the slip cone and disposed between the outer surface of the mandrel and the inner cover of the slip assembly cage and the attached hold down coupling and booster housing below the'slip assembly.

A fluid input port just above the lower slip cone permits pressurized fluid from below the packer to enter and travel upwardly between the mandrel and packing sleeve and beyond to actuate the booster piston and hold down piston.

As the hold down piston advances, a vacuum is created in the space one side of the piston and the adjacent wall structure. This vacuum facilitates later releasing of the slips.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, as well as additional objects and advantages thereof, will best be understood when the following detailed description is read in connection with the accompanying drawings, in which:

FIG. 1 is a segmented side elevational view, partly broken away and in section, of apparatus in accordance with this invention, and

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1..

DETAILED DESCRIPTION OF THE DRAWINGS Referring to the drawing, there is shown compression packer apparatus, indicated generally by the numeral 10, including an elongated tubular inner mandrel 12 having externally threaded ends coupled to an upper connector 14 and a lower connector 16, respectively. The upper connector 14 is a tubular element having internal threads at eaCh end, the lower end being coupled to the mandrel 12 and the upper end for coupling to a tubing string, for example.

There is an outwardly extending shoulder intermediate theends of the connector 14, the outer surface adjacent to the shoulder being threaded. An upper cage ring is coupled to the threads adjacent to the upper side of the shoulder.

A cage sleeve having cutouts through which slip elements 86 protrude is coupled at its upper end to the lower external threads of the connec'torl4. The lower end of the cage sleeve 70 is threadedly coupled to a hold down coupling 66.

An array of slip elements 86 each attached to a leaf spring 88 and supported from a ring-like block 90 disposed contiguous to the lower end of the upper connector l4.

The lower connector 16 is an elongated tubular member having external threads 98 at its lower end and a smooth cylindrical outer wall surface from adjacent to the threads 98 to the upper end of the member. A stud 24 extends outwardly from the upper end part of the connector 16.

A sleeve 26 containing a .l-shaped slot 100 therein fits closely but slidably around the lower connector and extending above the connector 16, being threadedly coupled at its upper end to the outer lower part of the lower slip cage 30 and thus to the drag blocks 32.

The outer periphery of the sleeve 26 is covered at least over the length of the J-slot 100 by the sleeve 28.

The drag blocks 32 extend through slots in a tubular sleeve 34 which fits over part of the outer surface of the lower slip cage 30.

The slip elements 36 are supported from the drag block members generally as shown in US. Pat. No. 3,710,866 or in U.S. Pat. No. 3,705,624 and extend upwardly beyond the sleeve 34 adjacent to the exterior of the mandrel l2.

The lower slip cone element 38 is disposed around the mandrel 12 above the slip elements 36. The cone element 38 is sleeve-like with internal threads at its upper end and a tapered conical end part at its lower end.

The element 38 iscounter-bored from its upper end to a point adjacent to the conical lower end. A fluid entry port 102 extends through the wall of the lower slip cone near the conical end, communicating with the counterbored part.

The internally threaded upper end of the cone element 38 is coupled to external threads at the lower end of a lower sleeve element 40 whose inner wall is of smaller diameter than the inner diameter of the counterbored part of the lower slip cone element.

A lower packing guide rim 44 of generally L-shaped transverse cross-sectional configuration surrounds the upper end of the lower sleeve element 40, presenting a flat surface perpendicular to the longitudinal axis of the mandrel 12.

One end of the rim bears against the upper end of the lower slip cone and the other end bears against the mandrel 12 with the adjacent side bearing against the upper end of the lower sleeve 40.

An array of packer ring elements 46 separated by metal spacer rings 48 are disposed over the mandrel l2 and extend between the lower packing guide rim 44 and an upper packing guide rim 50 which is similar in size and configuration to the guide rim 44.

The upper packing guide rim 50 at its lower end and its side bears against the lower end and outer side of the packer connection member 52 which is a sleeve-like member surrounding and spaced from the mandrel l2 and has an outwardly extending shoulder intermediate of its ends. The inner peripheral surface below the shoulder is threaded, as is the outer peripheral surface above the shoulder.

An elongated packing sleeve 42 has its upper end engaging with the inner peripheral threads of the packer connection 52 and is sealed with respect thereto by means of the O-ring seal 54 in the inner peripheral wall of connector 52.

The lower sleeve 40, lower packing guide rim 44, packer elements 46, spacer elements 48, and the upper guide rim 50 each fit slidably over the outer peripheral surface of the packing sleeve 42 which in turn is spaced from and fits over the outer periphery of the mandrel 12.

The lower end of the packing sleeve 42 has an outwardly extending shoulder which extends into the counterbored part of the lower slip cone 38. The diameter of the shoulder part exceeds the inner diameter of the lower sleeve 40.

A booster housing sleeve 58 is threadedly coupled to the upper threads of the packer connection member 52 and at its upper end to the lower external threads of the hold down coupling 66. A pressure relief port 64 is provided in the booster housing wall just below the hold down coupling 66.

An O-ring seal 56 is provided in the outer periphery of the upper part of the packer connection member 52 to provide a seal between the member 52 and the booster housing sleeve 58.

As mentioned previously, the parts between the booster housing and the lower slip cone surround the mandrel 12 and are spaced from it to provide a fluid passage from the port 102 to the booster housing sleeve 58.

The inner wall of the booster housing sleeve is smooth and of constant diameter, defining the inner cylinder wall in which the booster piston 60 is disposed.

The booster piston 60 is a sleeve-like member having an outwardly extending shoulder part at its lower end. An O-ring seal 62 is provided between the booster piston shoulder and the inner wall of the booster housing 58.

The upper end part of the booster piston 60 extends above the lower end of the hold down coupling 66. An O-ring seal 68 is provided between the shoulder and inner wall of the hold down coupling 66.

The hold down piston 72 lies between the outer surface of the mandrel l2 and the inner surface of the cage 70 and hold down coupling 66, with its lower end touching or adjacent to the upper end of the booster piston 60.

The hold down piston 72 is an elongated tubular element having a section of reduced outer diameter near its lower end where it fits slidably over the inner surface of the upper part of the hold down coupling 66. O-ring seals 74, 78 are provided between the outer surface of the hold down piston and the inner surface of the hold down coupling and the inner surface of the cage member 70, respectively.

The upper end of the hold down piston is coupled, by pin 84, to the lower end of the upper slip cone 80 which fits slidably between the mandrel 12 and cage 70. An O-ring wiper 82 is provided between the non-tapered outer surface of the upper slip cone 80 and the inner wall of the cage 70.

The upper end of the cone 80 is tapered to fit under, and on upward movement, force outwardly the upper slip elements 86.

An O-ring seal 104 is also provided between the hold down piston 72 and the outer wall of the mandrel 12 adjacent to the upper end of the piston 72.

OPERATION In operation, the apparatus 10 is usually lowered into a cased bore hole to a desired depth at or near the end of a string of tubing.

The drag block elements 32 provide considerable frictional contact with the casing wall (not shown). When the apparatus is in position in the casing, the tubing is rotated to place the boss or pin 24 in line with the long part of the .l-slot 26 and the tubing is then lowered, carrying the mandrel l2 and entire assembly down to the lower slip cone 38 downwardly. The lower slip cone 38 advances under the lower slip elements 36, forcing slip elements 36 outwardly to bite into the casing and prevent further downward movement of the apparatus.

As the mandrel 12 is moved downwardly to set the slip elements 36, the packing elements 46 are compressed and expanded to seal the annulus between the casing and the apparatus 10, the packing sleeve sliding downwardly as the elements 46 are compressed.

Once the packer elements seal the above-mentioned annular space, fluid is pumped through the tubing and mandrel 12 into the casing below the apparatus 10.

The pressurized fluid enters through the fluid input port 102 in the lower slip cone and rises in the space between the mandrel and the packing sleeve 42, packer connection 52, booster housing 58 and part of the hold down coupling 66 to put pressure on the booster piston 60 and hold down piston 72 to move the upper cone sleeve upwardly underneath the upper slip elements 86, forcing the slip elements 86 against the wall of the easing to prevent upward movement of the casing.

As the hold down piston 72 moves upwardly, a vacuum is created in the space left as the shoulder 106 of the hold down piston moves away from the upper end of the hold down coupling 66. Seals 74 and 78 assure that vacuum conditions are maintained in the space.

After the pressurized treatment of the well bore is completed, pressure is relieved on the tubing and the loss of pressure plus the vacuum created as the hold down piston advances results in the upper slip cone being retracted. The springs 88 then force the slip elements 86 inwardly.

The apparatus then may be moved upwardly by upward movement of the tubing, drawing the lower slip cone 38 upwardly and removing the compression of the packer elements 46.

If the apparatus is to be lowered into the casing (or to be moved in either direction, if wanted), the tub ing is rotated while under tension to place the boss or pin 24 in the rest position of the .l-slot 26 to prevent relative movement between the drag block elements 32 and the lower slip cone 38.

The total top area of the piston 72 exceeds the total area of the lower piston parts. Therefore, the well bore pressure and vacuum cause the return of the piston 72 to the at reat position, retracting the upper slip cone 80.

I claim: 7

1. Compression packer apparatus comprising an elongated tubular inner mandrel having upper connector means at one end and lower connector means at the lower end thereof, a slip element and compression packer element assembly including packer elements, drag blocks and a lower slip cone carried around the lower part of said mandrel assembly, means for mechanically compressing said packer elements and for advancing said lower slip cone under said slip elements, an upper slip array having a tapered under side disposed above said packer elements and surrounding said mandrel, a slidable upper slip cone disposed around said mandrel adjacent to said tapered underside of said slip array, hydraulic piston drive means coupled to said 7 upper slip cone and disposed around said mandrel, channel means for applying pressurized fluid from below said packer elements to said piston drive means, and vacuum actuated upper slip cone retraction means coupled to said piston drive means.

2. Apparatus in accordance with claim 1, wherein said hydraulic piston drive means includes an actuating piston and at least one booster piston, said pistons being disposed in end-to-end relationship.

3. Apparatus in accordance with claim 1, wherein sald means for mechanically compressing said packer elements includes at least one piston fitting closely between the outer surface'of said mandrel and an outer housing sleeve assembly. 7

4. Apparatus in accordance with claim 3, wherein the outer housing sleeve assembly has a reduced inner diameter part and said piston has a normal diameter part and has a reduced outer diameter part substantially coextensive in length with said reduced inner diameter part, said reduced inner and outer diameter parts telescoping closely but slidably with respect to each other, and spaced apart seal means between said piston and said outer housing sleeve for restricting fluid flow between said piston and said outer housing assembly whereby as said piston advances, a vacuum is created in the space between the parts of said piston and housing assembly having differing diameters.

5. Apparatus in accordance with claim 3, wherein said piston has a large diameter forward part and a reduced diameter rear part. and said housing assembly has a larger inner diameter forward part and a reduced outer diameter rear part, said parts being telescoped to a maximum extent when said upper slip cone is ret'racted and said differing diameter parts defining an open space when said upper slip cone is in its advanced position as a result of upward motion of said piston.

Claims

1. Compression packer apparatus comprising an elongated tubular inner mandrel having upper connector means at one end and lower connector means at the lower end thereof, a slip element and compression packer element assembly including packer elements, drag blocks and a lower slip cone carried around the lower part of said mandrel assembly, means for mechanically compressing said packer elements and for advancing said lower slip cone under said slip elements, an upper slip array having a tapered under side disposed above said packer elements and surrounding said mandrel, a slidable upper slip cone disposed around said mandrel adjacent to said tapered underside of said slip array, hydraulic piston drive means coupled to said upper slip cone and disposed around Said mandrel, channel means for applying pressurized fluid from below said packer elements to said piston drive means, and vacuum actuated upper slip cone retraction means coupled to said piston drive means.

3. Apparatus in accordance with claim 1, wherein saId means for mechanically compressing said packer elements includes at least one piston fitting closely between the outer surface of said mandrel and an outer housing sleeve assembly.

5. Apparatus in accordance with claim 3, wherein said piston has a large diameter forward part and a reduced diameter rear part and said housing assembly has a larger inner diameter forward part and a reduced outer diameter rear part, said parts being telescoped to a maximum extent when said upper slip cone is retracted and said differing diameter parts defining an open space when said upper slip cone is in its advanced position as a result of upward motion of said piston.