Patent Application
20090255682
1. Field of Invention
This invention relates in general to production of oil and gas wells, and in particular to a wellhead having a large bore tree that includes a hanger adapter in the bore, the plug having a passage therethrough to receive a control line.
2. Description of Related Art
Wellheads used in the production of hydrocarbons extracted from subterranean formations typically comprise a wellhead assembly. Wellhead assemblies are attached at the upper ends of wellbores that intersect hydrocarbon producing formations. Wellhead assemblies also provide support for tubing and casing inserted into the wellbore. The casing lines the wellbore, thereby isolating the wellbore from the surrounding formation. The tubing typically lies concentric within the casing and provides a conduit for producing the hydrocarbons entrained within the formation.
Wellhead assemblies also typically include a production tree connecting to the upper end of the wellhead housing. The production tree controls and distributes the fluids produced from the wellbore. Valves assemblies are typically provided within wellhead production trees for controlling the flow of oil or gas from a wellhead and/or for controlling circulating fluid flow in and out of a wellhead. Gate valves and other sliding stem-type valves have a valve member or disc and operate by selectively moving the stem to insert/remove the valve member into/from the flow of fluid to stop/allow the flow when desired.
A subsea wellhead assembly that includes a wellhead housing, a production tree, a tubing hanger adapted to land in the wellhead assembly inside the wellhead housing, and a bore formed through the production tree having an inner diameter greater than the tubing hanger outer diameter. A hanger adapter may be included having an annular body disposed on the tubing hanger upper surface and a flange member projecting radially outward from the annular body.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. For the convenience in referring to the accompanying figures, directional terms are used for reference and illustration only. For example, the directional terms such as “upper”, “lower”, “above”, “below”, and the like are being used to illustrate a relational location.
It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
A production tree 42 also included with the wellhead assembly 10 of
An annular hanger adapter 60 is shown disposed on the tubing hanger 18 upper end. The hanger adapter 60 includes an annular body 63 having radial dimensions substantially matching the tubing hanger 18. The hanger adapter 60 includes a flange 65 shown atop the body 63 that radially extends outward into contact with the bore 56 inner diameter. Seals 67 are shown provided in the interface between the flange 65 and bore 56 inner diameter. A lockdown mechanism (not shown) can be used for securing the hanger adapter 60 within the tree bore 56. An upper actuator passage 62 shown passing through the flange 65 and body 63 registers with the lower actuator passage 38. Above the hanger latch 20, the tubing hanger 18 outer surface transitions radially inward away from the high pressure housing 16 creating a shoulder 19 on the tubing hanger 18. A tubing hanger annulus 36 is shown in the annular space circumscribing the tubing hanger 18 and plug body 63 between the shoulder 19 and flange 65. The tubing hanger annulus 36 outer radius is bounded by the high pressure housing 16 and tree 42.
A circulation port 46 shown passing between the plug annulus 61 and the tree 42 outer diameter includes a circulation valve 48 for annulus pressure and fluid control through the port 46. A tubing annulus passage 34 is shown bored through the tubing hanger 18 and the high pressure housing 16; the tubing annulus passage 34 provides pressure and fluid communication between the tubing hanger annulus 36 and the tubing annulus 27. The combination of the tubing annulus passage 34, tubing hanger annulus 36, and plug annulus 61 creates a flow path to the circulation of fluid into the tubing annulus 27, such as during workover operations.
A selectively openable and closeable safety valve 30 is shown in the tubing 26 that provides pressure isolation between the wellhead assembly 10 and within the wellbore 5. The safety valve 30 is operable with the actuator 32 shown on the tubing, and can be electrically or hydraulically powered. A line 33 attached to the actuator 32 is shown that can provide electrical or hydraulic power. Extending upward from the actuator 32, the line 33 follows the path through the tubing annulus 27, the lower actuator passage 38, and into the upper actuator passage 62. The upper actuator passage 62 registers with a tree control line passage 64 shown formed through the tree 42. There, the line 33 connects to a lead 66 that extends from a subsea control module 68. The control line 33 may be disposed within the lead 66 or connected thereto for transferring either hydraulic fluid or electrical current through the line. In one embodiment, a pair of control lines is provided to and from the actuator 32 to complete the electrical or hydraulic circuit. As is known, the subsea control module 68 can provide control for operating the actuator 32 as well as any actuatable elements, such as valves and sliding sleeves, associated with the wellhead assembly 10. The passages 64, 62, 38 and annulus 27 form an actuation passage. Aligning the passages within the wellhead assembly 10 may require an orientation device when landing the hanger adapter 60 within the wellhead assembly 10. It is well within the capabilities of those skilled in the art to create and implement such an orientation.
One of the advantages of the device illustrated herein is the flexibility of installing particular components of the wellhead assembly 10 and in what order. For example, the wellhead housings 12, 16 and tree 42 can be installed prior to drilling the wellbore 5. As noted above, the tree bore 56 diameter can accommodate a drill bit therethrough. Referring now to
Referring back to
The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.
This application claims priority to and the benefit of co-pending U.S. Provisional Application Ser. No. 61/041,803, filed Apr. 2, 2008, the full disclosure of which is hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61041803 | Apr 2008 | US |
