METHOD AND APPARATUS FOR RETAINING WEIGHTED FLUID IN A TUBULAR SECTION

• US 20160312576A1
• Filed: 01/15/2014
• Published: 10/27/2016
• Est. Priority Date: 01/15/2014
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Webb, Earl Don, Rogers, Henry Eugene
• Granted Patent: US 9,835,008 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E21B 19/002 specially adapted for underwater drilling E21B19/09, E21B19/143 take precedence
• CPC Class Codes: E21B 21/10 Valve arrangements in drilling-fluid circulation systems
• CPC Class Codes: E21B 34/00 Valve arrangements for boreholes or wells
• CPC Class Codes: E21B 34/06 in wells

Abstract

A floating apparatus for use in a casing string and especially for use in offshore casing operations. The apparatus includes a valve configured such that, when there is a pressure differential across the valve below a predetermined mid-pressure threshold, the valve prevents fluid flow and, when the pressure differential exceeds a predetermined high-pressure threshold, said valve non-resiliently allows fluid flow across the valve.

Claims

1. A HOP assembly for a fluid filled casing string comprising:

a housing configured to attach to said casing string wherein said housing contains an adjustable one-way check valve, wherein hydrostatic forces resulting from fluid inside said casing string creates a pressure differential across said adjustable one-way check valve and said one-way check valve supports said hydrostatic forces such that it prevents fluid flow up to a first predetermined pressure differential so as to retain said casing string in a fluid filled state and wherein said one-way check valve is adjustable such that said first predetermined pressure differential can be increased or decreased.

2. The HOP assembly of claim 1 wherein said adjustable one-way check valve non-re-resiliently allows fluid flow when a second predetermined pressure differential is exceeded, wherein said second predetermined pressure differential is equal to or greater than said first predetermined pressure differential.

3. The HOP assembly of claim 2 wherein said second predetermined pressure differential is greater than said first predetermined pressure differential and, when said pressure differential is between said first predetermined pressure differential and said second predetermined pressure differential, said adjustable one-way check valve resiliently allows fluid flow.

4. A HOP nose for a casing string, comprising:

a housing having a first housing end configured for attachment to said casing string;

a second housing end;

an exterior face extending from said first housing end to said second housing end;

an interior face extending from said first housing end to said second housing end and defining a central bore; and

an aperture extending from said exterior face to said interior face; and

a valve positioned in said bore, said valve configured such that, when there is a pressure differential between said first housing end and said aperture below a predetermined mid-pressure threshold, said valve prevents fluid flow between said first housing end and said aperture, and when said pressure differential exceeds a predetermined high-pressure threshold, said valve non-resiliently allows fluid flow from said first housing end to said aperture.

5. The HOP nose of claim 4 wherein said predetermined mid-pressure threshold is equal to said predetermined high-pressure threshold.

6. The HOP nose of claim 4 wherein said predetermined mid-pressure threshold is less than said predetermined high-pressure threshold.

7. The HOP nose of claim 6 wherein, when said pressure differential is from said predetermined mid-pressure threshold to said predetermined high-pressure threshold, said valve resiliently allows fluid flow from said first housing end to said aperture.

8. The HOP nose of claim 7 wherein said valve comprises:

a valve seat located in said central bore;

a valve element having a sealing surface sealingly engageable with said valve seat;

a valve guide retainer attached to said housing and having an interior face defining a retainer passage;

a valve guide having a stem passage there through, said valve guide extending through said retainer passage and attached to said interior face of said valve guide retainer;

a valve stem extending from said valve element and through said valve guide;

said valve stem being slidably received through said valve guide; and

a spring between said valve element and valve guide, and providing a biasing force such that said valve element sealingly engages said valve seat until said pressure differential reaches said predetermined mid-pressure threshold.

9. The HOP nose of claim 8 wherein said valve element sealing engages said valve seat when said pressure differential is below said predetermined mid-pressure threshold;

resiliently disengages from said valve seat when said pressure differential is from said predetermined mid-pressure threshold to said predetermined high-pressure threshold and non-resiliently disengages from said valve seat when said pressure differential is above said predetermined high-pressure threshold.

10. The HOP nose of claim 9 wherein said valve guide is threadedly connected to said valve guide retainer such that turning said valve guide increases said biasing force exerted on said valve element and said valve guide and, thusly, increases said predetermined mid-pressure threshold.

11. The HOP nose of claim 10 wherein said valve guide retainer is shearingly attached to said housing such that when said pressure differential exceeds said predetermined high-pressure threshold, said valve guide retainer detaches from said housing.

12. The HOP nose of claim 11 wherein said first housing end is attached to a float assembly comprising:

an outer sleeve having a first sleeve end configured to be connected to said well casing, a second sleeve end attached to said first end of said housing, an outer surface and an inner surface, wherein said inner surface defines a central flow passage;

a check valve disposed in said central flow passage, said check valve comprising a check valve housing having an interior surface defining a central chamber in fluid flow communication with said central flow passage and an exterior surface opposing said inner surface of said outer sleeve wherein said exterior surface and inner surface define an annulus between said valve housing and said outer sleeve; and

a body portion fixedly attached to said housing and said outer sleeve, wherein said body portion fills said annulus.

13. The HOP nose of claim 12 wherein said check valve further comprises:

a check valve seat defined on said check valve housing;

a check valve guide disposed in said central chamber of said check valve housing;

a check valve element having a sealing surface sealingly engageable with said check valve seat; and

a check valve stem extending upwardly from said check valve element and slidably received through said check valve guide.

14. The HOP nose of claim 4 wherein said first housing end of said housing is attached to a float assembly comprising:

an outer sleeve having a first sleeve end configured to be connected to said well casing, a second sleeve end connected to said first end of said housing, outer surface and an inner surface, wherein said inner surface defines a central flow passage;

a check valve disposed in said central flow passage, said check valve comprising a check valve housing having an interior surface defining a central chamber in fluid flow communication with said central flow passage and an exterior surface opposing said inner surface of said outer sleeve wherein said exterior surface and inner surface define an annulus between said valve housing and said outer sleeve; and

a body portion fixedly attached to said housing and said outer sleeve such that said body portion fills said annulus.

15. The HOP nose of claim 14 wherein said valve further comprises:

a check valve seat defined on said check valve housing;

a check valve guide disposed in said central chamber of said check valve housing;

a check valve element having a sealing surface sealingly engageable with said check valve seat; and

a check valve stem extending from said check valve element and slidably received through said check valve guide.

16. A method of placing a casing string having an interior into a wellbore at the bottom of a body of water, the method comprising:

(a) attaching a HOP nose to said casing string, said HOP nose having an interior and an aperture, which allows fluid flow communication between said interior of said HOP nose and the outside of said HOP nose;

(b) lowering said casing through said water and into said wellbore;

(c) introducing a fluid into said interior of said casing, said fluid having a fluid pressure;

(d) during said lower lowering step (b), preventing fluid flow communication between said interior of said casing and said aperture of said HOP nose when said fluid pressure is below a predetermined mid-pressure threshold;

(e) after said lowering of step (b), preventing fluid flow communication between said interior of said casing and said aperture of said HOP nose only when said fluid pressure is below a predetermined low-pressure threshold, wherein said predetermined low-pressure threshold is less than said predetermined mid-pressure threshold.

17. The method of claim 16 wherein the density of said fluid is less than the density of the water of said body of water.

18. The method of claim 17 wherein fluid flow communication is controlled by a first check valve and a second check valve with said first check valve resiliently allowing fluid flow communication when said fluid pressure is at or above said predetermined low-pressure threshold and said second check valve resiliently allowing fluid flow communication when said fluid pressure is at or above said predetermined mid-pressure threshold.

19. The method of claim 18 further comprising, after said lowering step (b), the step of disabling said second check valve such that it non-resiliently allows fluid flow communication above and below said predetermined mid-point threshold.

20. The method of claim 19 wherein said step of disabling said second check valve comprises increasing said fluid pressure to above a predetermined high-pressure threshold wherein said predetermined high-pressure threshold is greater than said predetermined mid-pressure threshold.

21. The method of claim 20 wherein the density of said fluid is less than the density of the water of said body of water.