Well operations system

• US 20030116327A1
• Filed: 02/13/2003
• Published: 06/26/2003
• Est. Priority Date: 06/01/1992
• Status: Active Grant

• Current Assignee: Cooper Cameron Corporation (Schlumberger NV)
• Original Assignee: Cooper Cameron Corporation (Schlumberger NV)
• Inventors: Hopper, Hans Paul, Cassity, Thomas G.
• Granted Patent: US 7,093,660 B2
• Time in Patent Office: Days
• US Class Current: 166/382
• CPC Class Codes: E21B 33/03 Well heads; Setting-up thereof
• CPC Class Codes: E21B 33/0353 Horizontal or spool trees, i.e. without production valves in the vertical main bore
• CPC Class Codes: E21B 33/043 specially adapted for underwater well heads E21B33/0407, E21B33/047 take precedence
• CPC Class Codes: E21B 33/047 for plural tubing strings
• CPC Class Codes: E21B 34/02 in well heads

Abstract

A wellhead has, instead of a conventional Christmas tree, a spool tree (34) in which a tubing hanger (54) is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger (21) for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Claims

1. A wellhead comprising a wellhead housing (20);

a spool tree (34) fixed and sealed to the housing, and having at least a lateral production fluid outlet port (63) connected to a valve (70); and

a tubing hanger landed (54) within the spool tree at a predetermined angular position at which a lateral production fluid outlet port (61) in the tubing hanger is in alignment with that in the spool tree.

2. A wellhead according to claim 1, wherein there are complementary guide means (50, 59) on the tubing hanger (54) and spool tree (34) to rotate the tubing hanger into the predetermined angular position relatively to the spool tree as the tubing hanger is lowered on to its landing..

3. A wellhead according to claim 2, wherein the guide means are provided by complementary oblique edge surfaces (50, 59) one facing downwards on an orientation sleeve (58) depending from the tubing hanger and the other facing upwards on an orientation sleeve (45) carried by the spool tree.

4. A wellhead according to any one of the preceding claims, which includes a production casing hanger (23) carried in the housing (20) below the spool tree (34);

an isolation sleeve (45) which is sealed at its lower end to the production casing hanger and at its upper end to the spool tree to definer an annular void (48) between the isolation sleeve and the housing; and

an adapter (26) located in the annular space and providing part of a passage from the production casing annulus to a production casing annulus pressure monitoring port (49) in the spool tree, the adapter having a valve (28) for opening and closing the passage, and the valve being operable through the spool tree after withdrawal of the isolation sleeve up through the spool tree.

5. A wellhead according to claim 4, in which the valve is provided by a gland nut (28), which can be screwed up and down within a body (27) of the adapter (26) to bring parts (29, 30) of the passage formed in the gland nut and adapter body, respectively, into and out of alignment with one another.

6. A wellhead according to claim 4 or claim 5, when dependent on claim 3, in which the orientation sleeve i, provided within the isolation sleeve (45).

7. A wellhead according to any one of the preceding claims, wherein the spool tree (34) has a downwardly depending location mandrel (36) which is a close sliding fit within a bore of the housing (20).

8. A wellhead according to claim 7, in which an environmental seal (39) is provided between the spool tree (34) and the housing (20), and a production seal (40) is provided in series with the environmental seal between the location mandrel and either the wellhead housing or a production casing hanger.

9. A wellhead according to any one of the preceding claims, wherein at least one vertical production fluid bore in the tubing hanger (54) is sealed above the respective lateral production fluid outlet port (61) by means of a removable plug (66), and the bore through the spool tree (34) being sealed above the tubing hanger by means of a second removable plug (68).

10. A wellhead according to claim 9, wherein the first plug is a wireline plug (66) and the second plus is a stopper (68) which contains at least one opening closed by a wireline plug (69).

11. A wellhead according to claim 9 or claim 10, wherein a walkover port (73) extends laterally through the wall of the spool tree from between the two plugs (66, 68);

a tubing annulus fluid port (64) extends laterally through the wall of the spool tree from the tubing annulus; and

these two ports through the spool tree are interconnected via an external loop line containing at least one valve (71, 72).

12. A wellhead according to any one of the preceding claims, in which the tubing hanger (54) has at least two separate functional connections at its upper end, separate connectors (82, 83) being provided for selective access of a single bore running tool to one of the functional connections, each connector having a key (84) for entering a complementary formation (85) at the top of the spool tree to locate the connector in a predetermined angular orientation relatively to the spool tree.

13. A multi production bore wellhead according to claim 12, in which the tubing hanger (54) has at least two vertical production through bores (80, 81) each with a lateral production fluid flow port aligned with the corresponding port in the spool tree, at least two respective connectors (82, 83) being provided for selective connection of a single bore wire line running tool to one or other of the production bores, each connector having a key (84) for entering a complementary formation (85) at the top of the spool tree to locate the connector in a predetermined angular orientation relatively to the spool tree.

14. A wellhead according to any one of the preceding claims, wherein the tubing hanger (54) has a shoulder (56) with an orientation key which cooperates with a landing in the spool tree (34) to provide final direct relative angular orientation between the tubing hanger and spool tree.

15. A method of completing a cased well in which a production casing hanger (21) is fixed and sealed by a seal assembly to a wellhead housing (20), the method comprising, with a BOP (22) installed on the housing, removing the seal assembly and replacing it with an adapter (26) which in manipulatable between configurations in which a passage from the production casing annulus up past the production casing hanger is open or closed;

with the passage closed, removing the BOP and fitting to the housing above the production casing hanger a spool tree (34) having an internal landing for a tubing hanger (54);

installing a BOP (22) on the spool tree;

running a tool (44) down through the BOP and spool tree to manipulate the valve and open the passage;

inserting through the BOP and spool tree an isolation sleeve (45), which seals to both the production casing and spool tree and hence defines between the sleeve and casing an annular void (48) through which the passage leads to a production casing annulus pressure monitoring port (49) in the spool tree; and

running a tubing string down through the BOP and spool tree until the tubing hanger (54) lands in the spool tree with lateral outlet ports in the tubing hanger and spool tree for production fluid flow, in alignment with one another.

16. An apparatus for creating a second fluid barrier for the sealed connection between a production mandrel and a wellhead supporting and sealed to a hanger, comprising:

a member having first seals on one end and second seals on another end;

said one end extending into the production mandrel with said first seals sealingly engaging the production mandrel; and

said other end extending into the wellhead with said second seals sealingly engaging the hanger for isolating the hanger.—

17. The apparatus of claim 16 wherein said member includes an orientation surface for orienting a tubing hanger within the production mandrel.

18. The apparatus of claim 17 further including an alignment member on said member for aligning said member within the production mandrel.

19. The apparatus of claim 16 wherein said member creates an annular void between said member and the wellhead.

20. The apparatus of claim 16 wherein said member includes a support on said one end for supporting said member within the production mandrel and said other end creates a sliding engagement with the hanger.

21. An apparatus for completing a well comprising:

a wellhead supporting a hanger and a packing member for sealing said wellhead and hanger;

a production member disposed on said wellhead and a metal-to-metal seal for sealing said production member and wellhead;

an isolation member having first seals on one end and second seals on another end;

said production member supporting said isolation member;

said first seals sealingly engaging said production member;

said hanger slidingly receiving said another end of said isolation member; and

said second seals sealingly engaging said hanger for establishing a second seal to said metal-to-metal seal.

22. The apparatus of claim 21 wherein said isolation member creates an annular space between said isolation member and said wellhead.

23. The apparatus of claim 22 wherein said production member includes a fluid passageway extending from said annular space to an exterior of said production member.

24. The apparatus of claim 23 further including a test valve on said production member for controlling flow through said passageway.

25. The apparatus of claim 23 further including a second fluid passageway extending from said void to an annulus formed between said wellhead and hanger for monitoring or bleeding off fluid pressure in said annulus.

26. The apparatus of claim 25 further including an internal valve for controlling flow through said second fluid passageway.

27. The apparatus of claim 21 wherein said isolation member includes a bore therethrough having a diameter no smaller than the diameter of the flowbore of said hanger.

28. A method for completing a well comprising:

lowering a hanger suspending casing into the well;

supporting the hanger within a wellhead and creating a casing annulus;

sealing the hanger and wellhead;

connecting and sealing a production member to the wellhead forming a first fluid barrier;

lowering an isolation member into the production member and wellhead;

supporting and sealing the isolation member within the production member;

slidingly receiving one end of the isolation member within the hanger; and

sealing the isolation member and hanger thereby forming a second fluid barrier.

29. The method of claim 28 further including the step of supporting tubing within the production member and forming a third fluid barrier.

30. The method of claim 28 further including:

creating a fluid passageway from the casing annulus and through a wall of the production member; and

monitoring the fluid pressure in the casing annulus.—

31. The method of claim 30 further including the step of bleeding fluid pressure through the fluid passageway.

32. A flow completion system for controlling the flow of fluid from a well bore, the flow completion system comprising:

a tubing spool which includes a central bore that extends axially therethrough and a production outlet which communicates with the central bore;

a tubing hanger assembly which is supported in the central bore and which includes a production bore that extends axially therethrough and a production passageway that communicates between the production bore and the production outlet, the tubing hanger assembly supporting a tubing string which extends into the well bore and defines a tubing annulus surrounding the tubing string;

a first closure member positioned in the production bore above the production passageway;

a first seal positioned between the tubing hanger assembly and the tubing spool above the production passageway;

wherein the first closure member and the first seal comprise a first pressure-containing barrier between the well bore and a surrounding environment;

a second closure member which is positioned in the production bore above the first closure member; and

a second seal which is disposed on the tubing hanger assembly and positioned within the tubing spool above the, first seal;

wherein the second closure member and the second seal comprise a second pressure-containing barrier between the well bore and the environment; and

wherein both the first and the second barriers are associated with the tubing hanger assembly.

33. The flow completion system of claim 32 wherein the tubing hanger assembly includes a tubing hanger and a seal member supported in the central bore above the tubing hanger and through which passes the production bore.

34. The flow completion system of claim 32, wherein the first and second closure members each comprise a wireline deployable plug.

35. The flow completion apparatus of claim 32, wherein the first closure member comprises a first sealing member which is mounted on a wireline deployable plug body and the second closure member comprises a second sealing member which is mounted on a wireline deployable plug body above the first sealing member.

36. The flow completion system of claim 32, further comprising:

an ancillary bore which extends generally axially through the tubing hanger assembly from a lower end to an upper end of the tubing hanger assembly; and

an ancillary closure member which is positioned in the ancillary bore.

37. The flow completion system of claim 36, wherein:

the ancillary bore includes a generally lateral branch with a valve that is moveable to open and close the lateral branch.

38. The flow completion system of claim 32 further comprising a tree cap which comprises:

an annular body; and

means for securing the body to the tubing spool.

39. The flow completion system of claim 32, further comprising a connector with a seal stab for engaging the ancillary bore.

40. The flow completion system of claim 39, wherein the connector further comprises:

a fluid bore extending through the connector and which is adapted to be connected to a conduit; and

the fluid bore communicating with a bore in the seal stab;

wherein fluid communication may be established between the ancillary bore and the conduit through the seal stab.

41. The flow completion system of claim 32, further comprising:

a blowout preventer which is removably connectable to the top of the tubing spool and which includes a blowout preventer bore, a set of blowout preventer rams, and at least one choke and kill line that communicates with a portion of the blowout preventer bore which is located adjacent the blowout preventer rams; and

a tubing hanger tool which is removably connectable to the top of the tubing hanger assembly and which includes a cylindrical outer surface portion and a flowbore that communicates with the production bore;

an annulus passageway which communicates the tubing annulus with the outer surface portion;

wherein the blowout preventer rams are adapted to sealingly engage the outer surface portion above the annulus passageway;

whereby fluid communication between the tubing annulus and the blowout preventer choke and kill line may be established through the annulus passageway and the portion of the blowout preventer bore which is located below the blowout preventer rams.

42. The flow completion apparatus of claim 32, further comprising:

a tubing hanger tool which is removably connectable to the top of the tubing hanger assembly in a predetermined orientation;

the tubing hanger tool including a flow passageway therethrough and being sealed to the tubing spool; and

the tubing hanger tool having stabs received by the production bore and the ancillary bore in the tubing hanger assembly.

43. The flow completion apparatus of claim 42 wherein the flow passageway extends through one of the stabs for flow communication with the production bore or ancillary bore.

44. A well production assembly located at an upper end of a string of tubing extending into a well, comprising:

a production tree having a longitudinal axis, an axial bore and a lateral production passage, the lateral production passage having an inlet at the bore and extending laterally through a sidewall of the production tree;

a tubing hanger landed in the axial bore and adapted to be located at an upper end of a string of tubing, the tubing hanger having a co-axial production passage co-axial with the production tree axial bore and extending axially through the tubing hanger and the tubing hanger having a lateral production passageway which extends laterally from the co-axial production passage through the tubing hanger and has an outlet at the exterior of the tubing hanger which registers with the inlet of the lateral production passage of the production tree;

the tubing hanger having an offset vertical passage extending through the tubing hanger from a lower end to an upper end of the tubing hanger offset from the co-axial production passage, the offset vertical passage having a lower end adapted to be in communication with a tubing annulus surrounding the string of tubing;

a first closure member installed in the co-axial production passage above the lateral production passageway of the tubing hanger; and

a second closure member installed in the offset vertical passage.

45. The well production assembly according to claim 44, further comprising:

a removable internal tree cap which sealingly engages the bore of the tree above the tubing hanger, the tree cap having first and second vertical passages which are offset from and parallel to each other, the first vertical passage of the tree cap aligning with the;

co-axial production passage of the tubing hanger, the second vertical passage of the tree cap aligning with the offset vertical passage of the tubing hanger;

a third closure member installed in the first vertical passage of the tree cap; and

a fourth closure member installed in the second vertical passage of the tree cap.

46. The well production assembly according to claim 44, further comprising:

a lateral flow passage extending laterally from the offset vertical passage through the tubing hanger and having an opening at the exterior of the tubing hanger; and

a tree flow passage having an opening in the axial bore of the tree and extending laterally through the tree for sealingly registering with the opening of the lateral flow passage of the tubing hanger.

47. A well production assembly located at an upper end of a string of tubing extending into a well, comprising:

a production tree having a longitudinal axis, an axial bore and first and second lateral passages, the first and second lateral passages having an inlet at the bore and extending laterally through a sidewall of the production tree;

a tubing hanger landed in the axial bore and adapted to be located at an upper end of a string of tubing, the tubing hanger having a co-axial production passage co-axial with the production tree axial bore and extending axially through the tubing hanger and the tubing hanger having a first lateral passageway which extends laterally from the co-axial production passage through the tubing hanger and has an outlet at the exterior of the tubing hanger which registers with the inlet of the first lateral passage of the production tree;

the tubing hanger having an offset passage extending through the tubing hanger from a lower end to an upper end of the tubing hanger offset from the co-axial production passage and a second lateral passageway which extends laterally from the offset vertical passage through the tubing hanger and -has an outlet at the exterior of the tubing hanger which registers with the inlet of the second lateral passage of the tree;

a first closure member installed in the co-axial production passage above the first lateral passage of the tubing hanger; and

a second closure member installed in the offset passage above the second lateral passageway of the tubing hanger.

48. A well production assembly comprising in combination:

a production tree having a vertical axis, an axially extending bore, and a lateral production passage extending from the bore through a sidewall of the tree transverse to the vertical axis;

a shoulder formed on the tree;

a tree auxiliary passage extending through the sidewall of the tree and having an auxiliary connector located at the shoulder;

a string of tubing extending into a well;

a tubing hanger which lands sealingly in the bore and is connected to the string of tubing, the tubing hanger having a lateral production passage extending from a co-axial production passage co-axial with the axially extending bore and extending axially through the tubing hanger, the lateral production passage aligning with the lateral production passage of the tree; and

a mandrel ;

disposed in the wellhead and having a mandrel auxiliary passage extending therethrough, the auxiliary connector in the tree sealingly mating with the auxiliary passage when the tree lands on the wellhead to communicate the tree auxiliary passage with the mandrel auxiliary passage.

49. The well production assembly of claim 48 wherein the mandrel auxiliary passage is used to test seals between the wellhead and spool tree.

50. The well production assembly of claim 48 wherein the tubing hanger has an offset vertical passage extending through the tubing hanger from a lower end to an upper end of the tubing hanger offset from the co-axial production passage and a lateral flow passageway which extends laterally from the co-axial production passageway through the tubing hanger and has an outlet at the exterior of the tubing hanger which registers with the inlet of a lateral flow passage in the tree.

51. In a subsea wellhead system having a wellhead housing secured to a first string of casing, a production casing hanger having an interior surface and an exterior surface and landed in the wellhead housing and secured to a production casing inside the first string of casing and extending below the production casing hanger, a casing hanger packoff that seals between the exterior surface on the production casing hanger and the wellhead housing, and a tree assembly that lands on the wellhead and has an axial bore, the improvement comprising:

a casing hanger communication passage passing through the production casing hanger and by-passing the production casing hanger packoff; and

a port closure sleeve releasably secured to the production casing hanger to open and close the communication passage.

52. A wellhead assembly comprising:

a wellhead housing;

a spool tree fixed and sealed to the housing, and having at least a lateral production fluid outlet port connected to a valve;

a production casing hanger carried in the housing below the spool tree;

an isolation sleeve which is sealed at its lower end to the production casing hanger and at its upper end to the spool tree to define an annular void between the isolation sleeve and the housing; and

an adapter located in the annular void and providing part of a passage from a production casing annulus to a production casing annulus pressure monitoring port in the spool tree, the adapter having a valve for opening and closing the passage, the valve being operable through the spool tree when the isolation sleeve is uninstalled in the spool tree.

53. The wellhead assembly of claim 52 further including:

a tubing hanger landed within the spool tree at a predetermined angular position at which a lateral production fluid outlet port in the tubing hanger is in alignment with that in the spool tree;

the tubing hanger and spool tree having complementary guide means to rotate the tubing hanger into the predetermined angular position relatively to the spool tree as the tubing hanger is lowered onto its landing, the guide means being provided by complementary oblique edge surfaces, one facing downwards on an orientation sleeve depending from the tubing hanger and the other facing upwards on an orientation sleeve carried by the spool tree.