1. Field of Invention
The device described herein relates generally to wellhead assemblies, and in particular to provide a connector for a data and/or power signal line integral with wellhead assembly components.
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 trees that connect to the upper end of the tubing and distribute the produced fluids, provide an injection means into the well, or another well related operation.
Sensors measuring pressure, temperature, or other downhole conditions, as well as electrical pumps may be disposed within production tubing that is used in producing wellbore fluids. Electrical signals representing sensor recordings are typically transmitted via a hardwire circuit, that typically includes wires or other conducting elements, connecting the sensors to a surface element. The surface element may comprise a control panel, an information handling system, a digital recording device, an analog recording device, and any other device or system for recording and/or analyzing sensor data.
Making up the wellhead assembly typically involves stabbing the tree onto a wellhead housing. Mating male/female electrical connectors are provided respectively in the tree and the wellhead housing to complete the hardwired circuit between the sensors and the surface. The connectors have traditionally been rigid members having a male and a female fitting that connect when the tree is stabbed on to the wellhead housing. These rigid connectors occupy a certain amount of space within the wellhead housing that reduces the amount of tubing cross sectional area. Additionally, the connectors may be offset from the production tubing housing, or in the case of a horizontal tree the connectors may extend laterally from the tree to the tubing hanger; thus the tree must be oriented in a proper radial position to ensure mating of corresponding male and female connections of the electrical connection.
The present device comprises a signal connector integral with standard wellhead assembly components. The connector comprises a conducting element, such as a wire, disposed within an annular member connected to a wellhead tree. One example of an annular member on a conventional tree is a stab unit. The lower terminal end of the stab unit is coaxial with wellbore production tubing within a wellhead assembly. Another example is a tubing hanger. The connection also comprises electrical contacts between a point in the annular stab/tubing hanger and the tree and wellhead hardware housed within a wellhead housing. In one embodiment, the lower connector is housed within a tubing hanger. Optionally, the electrical contacts at the upper and lower end of the annular stab are wet connects. The electrical connector may comprise an annular member that mates with a corresponding conducting element. Thus, the need for a dedicated connector is not required, which allows for additional annular space to be used by production tubing.
Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
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.
The tree 7 is attached to the wellhead housing 9 by an external connector 17. The type of tree 7 is not limited to the embodiment illustrated, but can include any type of tree, including a production tree, an injection tree, and other members mounted on a wellhead having valves to direct flow in and/or out of a wellbore. The housing 9 includes therein production tubing 42, a tubing hanger 21, and a casing hanger 23. The casing hanger 23, which is a generally annular member, is coaxially secured within a portion of the housing 9. Pack offs 19 (also referred to as casing hanger seals) are disposed between the outer circumference of the casing hanger 23 in a portion of the inner circumference of the housing 9. An inner bowl 24 is provided within the casing hanger 23 formed to receive the tubing hanger 21. Optionally, the tubing hanger 21 can land on top of the casing hanger 23 and seal on the wellhead housing 9. Production tubing 42 extends downward into the wellbore 3 from the tubing hanger 21. An annular isolation sleeve 30 is shown extending coaxially within the tree 7 to within the tubing hanger 21. As shown, wellbore flow from the production tubing 42 may reach the production bore 11 through the isolation sleeve 30. The upper end of the isolation sleeve 30 is sealed to the production bore 11 and the lower end to tubing hanger 21 by seals (not shown).
A sensor 46 is schematically depicted in a portion of the tubing 42 that protrudes within the wellbore 3. The sensor 46 may be used for sensing pressure, temperature, or other downhole conditions. Optionally, multiple sensors may be employed with the embodiment described herein. The sensor 46 comprises a portion of a wellbore sensing system having a monitoring/recording means at the surface. An example of sensor 46 to surface communication is illustrated by a signal medium 44 shown passing through the tubing 42 sidewall, up the annulus between the tubing 42 and casing 25, and exiting the tree 7. The signal circuit 45 may include any element used for conveying a signal, examples include electrically conducting wire, fiber optic members, connectors, and pneumatic lines, to name but a few. Optionally, a medium for conducting electrical power may also be included with the wellhead assembly 5 and routed the same as or similar to the signal circuit 45. The power conducting medium, such as for example an electrically conducting wire, may be disposed in the same bore or passage as the signal circuit 45, in place of the signal circuit 45, or azimuthally from the signal circuit 45. In one optional embodiment, the signal circuit 45 and electrically conducting medium are combined in a single medium/conduit configured to transmit both signals and electrical power. In another optional embodiment, the signal transmitted in accordance with the present description includes one or more data signals. Optionally, the data signals may include a broad band signal.
The signal circuit 45 comprises segments that pass through, along, or adjacent various production hardware components. Each segment is individually referenced for clarity; for example, the segment of the conduit in the annulus 26 between tubing 42 and casing 25 is referred to as the annular annulus wire 44. A passage 47 shown through the tubing hanger 21 provides a pathway for the signal circuit 45 to the isolation sleeve 30. This segment of the signal circuit 45 is referred to as the tubing hanger wire 40. Another passage 48 shown formed through the isolation sleeve 30 wall having a sleeve wire 36 segment. Connectors 32, 38 are shown respectively provided at the upper and lower terminal ends of the isolation sleeve 30. The sleeve wire 36 upper and lower ends join the connectors 32, 38. In the embodiment shown, these connectors 32, 38 include gallery ring connectors circumscribing the isolation sleeve 30. The annular connector 32 provides communication between the sleeve wire 36 and the feed wire; the annular contact 38 provides communication between the sleeve wire 36 and the tubing hanger wire 40. The seals on the isolation sleeve 30 prevent exposing the contacts to corrosive well fluids thus extending connector life. The feed wire 34, shown in dashed outline, extends from the connector 32 to outside of the tree 7. Embodiments exist having multiple electrical connectors on the isolation sleeve 30 with associated sleeve wires 36.
Examples of the connectors 32, 38 are shown in perspective view in
The embodiment of
An alternative connector embodiment for use in a wellhead assembly 58 is provided in a side sectional view in
Referring now to
In one example of use, the sensor 46 emits a signal that is conducted through the remaining portions of the signal circuit 45. The signal can be digital or analog, and can represent a condition or property detected by the sensor 46. The signal can be stored in memory subsea, or transmitted realtime from subsea to above the sea surface. The signal can be used for well monitoring or well control, thus above surface signal remote destinations can include a production control facility, a workover rig, as well as a workboat. The sensor circuit 45 can further include a return path for control signals provided from one or more of the remote destinations.
Accordingly, implementation of the present device allows for signals to be safely transmitted from within the wellbore to the surface via the normal production/annulus stingers, for example between the tree and the tubing hanger. This eliminates the potential for damage that can occur with currently known electrical connectors.
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. For example, the connector ring may comprise a pair of concentric rings with the inner ring integral with the stab member and the outer ring integral with the wellhead assembly. Additionally, multiple isolated electrical connectors may be included with embodiments of the device disclosed herein. Optionally each connection is insulated from the other. In another alternative, the electrical return or ground can either be via one of the above described connections or to earth. In the case of a horizontal tree the embodiment may be incorporated onto existing hydraulic control line couplers or on an alternative lateral entry production stab. 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.
This application claims priority to and the benefit of co-pending U.S. Provisional Application Ser. No. 61/034,402, filed Mar. 6, 2008, the full disclosure of which is hereby incorporated by reference herein.
Number | Date | Country | |
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61034402 | Mar 2008 | US |