Pack-off system

• US 6,253,856 B1
• Filed: 11/06/1999
• Issued: 07/03/2001
• Est. Priority Date: 11/06/1999
• Status: Expired due to Term

• Current Assignee: Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: Weatherford/Lamb Incorporated (Weatherford International PLC)
• Inventors: Ingram, Gary Duron, Hoffman, Corey Eugene
• Primary Examiner(s): Tsay, Frank
• Application Number:
  US09/435,388
• Time in Patent Office: 605 Days
• Field of Search: 166/374, 166/373, 166/120, 166/387, 166/187, 166/191
• US Class Current: 166/374
• CPC Class Codes: E21B 33/124 Units with longitudinally-spaced plugs for isolating the intermediate space
• CPC Class Codes: E21B 34/08 responsive to flow or pressure of the fluid obtained E21B34/10 takes precedence

Abstract

A pack-off system for packing off an area of interest in a wellbore, the pack-off system comprising a body, two spaced-apart selectively settable packing elements on the body for sealing off the area of interest, selectively actuatable setting apparatus connected to the body for selectively setting the two spaced-apart selectively settable packing elements, the selectively actuatable setting apparatus actuatable by fluid under pressure introduced into the pack-off system. A method for packing off an area of interest in a wellbore, the method including installing a pack-off system as described herein in the wellbore to pack-off the area of interest. Such a method may also include flowing treatment fluid from the pack-off system to an area of interest in an earth formation and/or adjacent a wellbore in the earth.

Claims

1. A pack-off system for packing off an area of interest in a wellbore, the pack-off system comprising

a body,

two spaced-apart selectively settable packing elements on the body for sealing off the area of interest,

selectively actuatable setting apparatus connected to the body for selectively setting the two spaced-apart selectively settable packing elements,

the selectively actuatable setting apparatus actuatable by fluid under pressure introduced into the pack-off system,

release apparatus selectively actuatable by reducing pressure of fluid pumped to the pack-off system to selectively release the two spaced-apart selectively settable packing elements,

the selectively actuatable setting apparatus further comprising

two movable member apparatuses subject to force of the fluid under pressure introduced into the pack-off system,

one of the movable member apparatuses movable in response to the force of the fluid under pressure to contact each of the two spaced-apart selectively-settable packing elements to boost sealing of said elements for sealing off the area of interest,

wherein the area of interest is an area adjacent a bore of a string in the wellbore, the pack-off system is disposed in said bore, and the two spaced-apart selectively-settable packing elements are settable to seal off said bore, and

a string to a lower end of which the pack-off system is connected.

2. The pack-off system of claim 1 further comprising

the string from the group consisting of coiled tubing, fiber optic line system, slick line, electrically conductive wireline, electrically non-conductive wireline, tubing, and casing.

3. The pack-off system of claim 1 further comprising

the body has at least one body flow port through which fluid is flowable from inside the pack-off system to the outside thereof,

the release apparatus comprises a shut off sleeve movably mounted in the body and responsive to force of the fluid under pressure introduced into the wellbore and into the pack-off system, the shut-off sleeve having an orifice therethrough and a top-to-bottom fluid flow bore, flow through the orifice initially blocked by a portion of the body,

a nozzle connected to the body, the nozzle having a fluid flow bore therethrough initially in fluid communication with the fluid flow bore of the shut-off sleeve, the nozzle having at least one exit port through which fluid can exit from the nozzle,

a spring abutting the body and the shut-off sleeve and urging the shut-off sleeve upwardly so that initially the shut-off sleeve does not close off flow to the at least one exit port of the nozzle,

the top-to-bottom fluid flow bore through the shutoff sleeve sized so that fluid under pressure is pumpable to the shut-off sleeve at a level sufficient to move the shut-off sleeve downwardly against force of the spring to align the orifice with the at least one body flow port and to close off flow to the at least one exit port of the nozzle so that fluid pressure builds up in the pack-off system and fluid under pressure exits from within the shut-off sleeve through the orifice and flows to the at least one body flow port and exits from the pack-off system.

4. A pack-off system for packing off an area of interest in a wellbore, the pack-off system comprising

a body,

two spaced-apart selectively settable packing elements on the body for sealing off the area of interest,

selectively actuatable setting apparatus connected to the body for selectively setting the two spaced-apart selectively settable packing elements,

the selectively actuatable setting apparatus actuatable by fluid introduced into the pack-off system at a desired rate of introduction, and

release apparatus selectively actuatable by reducing the rate of introduction of fluid introduced to the pack-off system to selectively release the two spaced-apart selectively settable packing elements.

5. The pack-off system of claim 4 wherein

the selectively actuatable setting apparatus further comprising

at least two movable member apparatuses subject to force of the fluid introduced into the pack-off system,

one each of the movable member apparatuses movable in response to the force of the fluid under pressure to contact one of the two spaced-apart selectively-settable packing elements to boost sealing of said elements for sealing off the area of interest.

6. The pack-off system of claim 4 wherein the area of interest is an area adjacent a bore of a tubular string in the wellbore, the pack-off system is disposed in said bore, and the two spaced-apart selectively-settable packing elements are settable to seal off said bore.

7. The pack-off system of claim 4 wherein the area of interest is within a bore of an item in the wellbore.

8. The pack-off system of claim 4 further comprising

a string to a lower end of which the pack-off system is connected,

the string from the group consisting of coiled tubing, fiber optic line system, slick line, electrically conductive wireline, electrically non-conductive wireline, tubing, and casing.

9. The pack-off system of claim 4, said pack-off system for straddling part of a bore in which the pack-off system is located, the pack-off system further comprising

two spaced-apart pack-off mandrels,

the two spaced-apart selectively-settable packing elements each on one of the spaced-apart pack-off mandrels,

a tubular member with a portion within each pack-off mandrel, the tubular member selectively movable with respect to the pack-off mandrels,

two spaced-apart setting sleeves secured to and movable with the tubular member, each setting sleeve movable to set one of the two spaced-apart selectively-settable packing elements,

two spaced-apart latch apparatuses each latch apparatus connected to one of the spaced-apart pack-off mandrels for releasably holding the tubular member and two spaced-apart pack-off mandrels in a first position in which the two spaced-apart selectively-settable packing elements are not set,

the tubular member having a fluid flow bore therethrough with a selectively closable lower end so that fluid pumped under pressure into the pack-off system and into the fluid flow bore of the tubular member moves the tubular member with respect to and apart from the two spaced-apart pack-off mandrels releasing the latch apparatus so that the setting sleeves move with the tubular member to set the two spaced-apart selectively settable packing elements against an interior of the bore in which the pack-off system is located.

10. The pack-off system of claim 9 wherein the two-spaced latch apparatuses are movable in response to the fluid under pressure to boost sealing of the area of interest by the two-spaced-apart selectively settable packing element.

11. The pack-off system of claim 4 wherein

the body has at least one body flow port through which fluid is flowable from inside the pack-off system to the outside thereof,

the release apparatus comprises a shut off sleeve movably mounted in the body and responsive to force of the fluid introduced under pressure into the wellbore and into the pack-off system, the shut-off sleeve having an orifice therethrough and a top-to-bottom fluid flow bore, flow through the orifice initially blocked by a portion of the body,

a nozzle connected to the body, the nozzle having a fluid flow bore therethrough initially in fluid communication with the fluid flow bore of the shutoff sleeve, the nozzle having at least one exit port through which fluid can exit from the nozzle,

a spring abutting the body and the shut-off sleeve and urging the shut-off sleeve upwardly so that initially the shut-off sleeve does not close off flow to the at least one exit port of the nozzle,

the top-to-bottom fluid flow bore through the shut-off sleeve sized so that fluid under pressure is pumpable to the shut-off sleeve at a level sufficient to move the shut-off sleeve downwardly against force of the spring to align the orifice with the at least one body flow port and to close off flow to the at least one exit port of the nozzle so that fluid pressure builds up in the pack-off system and fluid under pressure exits from within the shut-off sleeve through the orifice and flows to the at least one body flow port and exits from the pack-off system.

12. A pack-off system for packing off an area of interest in a wellbore, the pack-off system comprising

a body,

two spaced-apart selectively settable packing elements on the body for sealing off the area of interest,

selectively actuatable setting apparatus connected to the body for selectively setting the two spaced-apart selectively settable packing elements,

the selectively actuatable setting apparatus actuatable by fluid introduced into the pack-off system at a desired rate of introduction, and

at least two movable member apparatuses subject to force of the fluid introduced into the pack-off system, and

one each of the movable member apparatuses movable in response to the force of the fluid under pressure to contact one of the two spaced-apart selectively-settable packing elements to boost sealing of said elements for sealing off the area of interest.

13. A method for packing off an area of interest in a wellbore, the method comprising

installing a pack-off system in the wellbore to pack-off the area of interest, the pack-off system comprising a body, two spaced-apart selectively settable packing elements on the body for sealing off the area of interest, selectively actuatable setting apparatus connected to the body for selectively setting the two spaced-apart selectively settable packing elements, the selectively actuatable setting apparatus actuatable by fluid introduced into the pack-off system at a desired rate of introduction,

actuating the selectively actuatable setting apparatus to set each of the two spaced-apart selectively settable packing elements by introducing fluid to the pack-off system,

wherein the pack-off system further comprises release apparatus selectively actuatable by reducing the rate of introduction of fluid introduced to the pack-off system to selectively release the two spaced-apart selectively settable packing elements, and the method further comprises

actuating the release apparatus by reducing rate of introduction of the fluid thereby releasing the two spaced-apart selectively-settable packing elements.

14. The method of claim 13 further comprising

moving the pack-off system to another location within the wellbore and again setting the two spaced-apart selectively settable packing elements.

15. The method of claim 13 further comprising

retrieving the pack-off system from the wellbore.

16. The method of claim 13 wherein the pack-off system includes movable member apparatus movable in response to fluid pressure for boosting sealing effects of the two spaced-apart selectively settable packing elements, the method further comprising

boosting sealing effects of the two spaced-apart selectively settable packing elements.

17. The method of claim 13 wherein the area of interest is an area adjacent a bore of a tubular string in the wellbore, the pack-off system is disposed in said bore, and the two spaced-apart selectively-settable packing elements are settable to seal off said bore.

18. The method of claim 13 wherein the area of interest is within a bore of an item in the wellbore.

19. The method of claim 13 wherein the pack-off system is connected to a lower end of a string, the string from the group consisting of coiled tubing, fiber optic line system, slick line, electrically conductive wireline, electrically non-conductive wireline, tubing and casing.

20. The method of claim 13 wherein the pack-off system has fluid exit apparatus for flowing fluid from within the pack-off system to an outside thereof, the method further comprising

flowing fluid from within the pack-off system to the outside thereof.

21. The method of claim 20 wherein the two spaced-apart selectively settable packing elements are set to pack-off a bore through an earth formation area of interest and wherein the fluid flowing from within the pack-off system to the outside thereof is formation treatment fluid that flows from the pack-off system, through any tubular in which the pack-off system is located, to the earth formation area of interest for treatment thereof.

22. The method of claim 13 wherein the fluid is pumped to the pack-off system from an earth surface pumping apparatus.

23. The method of claim 13 wherein the fluid is pumped to the pack-off system from an apparatus within the wellbore.