WELL REENTRY
A system includes a plug configured to restrict release of hydrocarbons from a terminal end of an offshore riser by accumulating the hydrocarbons at the plug when the plug is disposed in an internal portion of the offshore riser and at a first vertical location of the offshore riser. The system also includes a vent configured to be disposed at a second vertical location, wherein the vent is configured to provide a path for the hydrocarbons to be released from the offshore riser.
This application is a Non-Provisional application of U.S. Provisional Patent Application No. 62/702,467, entitled “Well Reentry” filed Jul. 24, 2018, which is herein incorporated by reference.
BACKGROUNDThis section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
When offshore wells (e.g., oil and/or gas wells) have reached their end-of-life they are to be decommissioned. Decommissioning of the wells involves, for example, plugging of the wellbore and disposal of the equipment used in offshore oil production. To finalize a decommissioning of a well, the well may be adequately plugged and abandoned. In order to plug and abandon the well, a drilling contractor reenters the well. However, wells that are not yet decommissioned may leak hydrocarbons (e.g., natural gas), which can present problems for reentry of the well, thus complicating the decommissioning of the wells.
One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Offshore oil and/or gas well decommissioning involves, in part, well plugging and abandonment as well as subsequent conductor removal. The well plugging and abandonment operation may include, for example, steps to seal the well (e.g., using cement or other sealant materials) as well as removal of the conductor casing to a particular distance below the seafloor (e.g., to a distance that conforms with local regulations). To plug and abandon the well, a drilling contractor will reenter the well, for example, by running casing into the well. However, in many instances, wells (e.g., previously abandoned wells) may be leaking hydrocarbons (e.g., natural gas), which increases the difficulty of tieback of the well for reentry from a drilling rig. For example, gas or other hydrocarbons leaking from an annulus of an offshore well may impede rigging up a blowout preventer (BOP) atop a tieback casing string. Accordingly, devices and methods to evacuate gas from a casing to allow for well plugging and abandonment to proceed are described herein.
With the foregoing in mind,
The present self-elevating unit 2 includes one or more legs 4 and the self-elevating unit 2 is capable of floating on a hull 6 (e.g., a buoyant hull), which may also operate to support the legs 4 of the self-elevating unit 2. As illustrated in
As further illustrated in
To finalize reentry of the well 12, the riser 20 may be cut or otherwise severed at the surface 8 (e.g., at the end of the riser 20 located at the offshore platform 10, here, the self-elevating unit 2, at or above a waterline) to properly size the riser 20 to extend a distance (e.g., a predetermined distance) from the self-elevating unit 2 to the well 12. A connector (e.g., a starter wellhead or another connector) may be welded or otherwise affixed to the riser 20 at the surface 8 (e.g., at the self-elevating unit 2) to operate as a connection point for attachment of a BOP to the riser 20 at the surface 8. The BOP may include at least one valve with a sealing element to control wellbore fluid flows. Other embodiments of the offshore platform 10 that operate in a similar manner as that discussed above are additionally contemplated.
For example,
As illustrated in
To finalize reentry of the well 12, the riser 20 may be cut or otherwise severed at the surface 8 (e.g., at the end of the riser 20 located at the offshore platform 10) to properly size the riser 20 to extend a distance (e.g., a predetermined distance) from the offshore platform 10 to the well 12. A connector (e.g., a starter wellhead or another connector) may be welded or otherwise affixed to the riser 20 at the surface 8 (e.g., at the offshore platform 10) to operate as a connection point for attachment of a BOP to the riser 20 at the surface 8. The BOP may include at least one valve with a sealing element to control wellbore fluid flows.
As illustrated in
Also illustrated in
Thus, as illustrated in
Additionally in step 51, the plug 30 may be placed into the riser 20, for example, at a distance of approximately 1 foot, 2 feet, 3 feet, 4 feet, 5 feet or another distance below a location of the connection point 40. If the plug 30 is expandable, it may be expanded once disposed in the riser 20. Placing the plug 30 into the reentry system 28 may operate to seal hydrocarbons 26 in the body 58. Alternatively, the plug 30 may be actuated (e.g., expanded) to seal hydrocarbons 26 in the body 58.
In step 52, the riser may be landed and engaged with (coupled to) the well 12, for example, using casing threads 24 or other connectors in the conductor 16 and/or the casing 18 to couple the riser 20 to the well 12. As part of step 52, the riser 20 may be made up to a mudline suspension system of the well 12, which may incorporate one or more tieback tools to reconnect the mudline hanger to the surface 8 to facilitate reentry of the well 12. In step 53, evacuation of the hydrocarbons 26 may be undertaken (if any are present in region 42). This step 53 may include attachment of the line 44 (if not already completed), activation of the vacuum 48, and opening of the valve 34 to begin evacuation of the hydrocarbons 26. In step 54, the connector 38 may be attached to the riser 20. Attachment of the connector 38 may include, for example, cuts to the riser 20 at the connection point 40 (e.g., to properly size the riser 20 to a length, such as a predetermined length) as well as affixing of the connector 38 (e.g., welding or other affixing techniques) to the riser 20 at the connection point 40 and in step 55, the BOP may be attached to the connector 38, to be used in ongoing program of work (i.e., decommission of the well 12).
As illustrated, the vent 32 may be coupled to a valve 34 (e.g., an isolation valve) which may include or otherwise be coupled to a connector 36, such as a stab connector. In operation, the valve 34 may be opened to provide a path for accumulated hydrocarbons 26 through the vent 32. Also illustrated in
Thus, as illustrated in
Additionally in step 64, the plug 30 may be placed into the reentry system 56, for example, at a distance of approximately 1 foot, 2 feet, 3 feet, 4 feet, 5 feet or another distance below a location of the connection point 40. If the plug 30 is expandable, it may be expanded once disposed in the reentry system 56. Placing the plug 30 into the reentry system 56 may operate to seal hydrocarbons 26 in the body 58. Alternatively, the plug 30 may be actuated (e.g., expanded) to seal hydrocarbons 26 in the body 58.
In step 52, the riser may be landed and engaged with (coupled to) the well 12, for example, using casing threads 24 or other connectors in the conductor 16 and/or the casing 18 to couple the riser 20 to the well 12. As part of step 52, the riser 20 may be made up to a mudline suspension system of the well 12, which may incorporate one or more tieback tools to reconnect the mudline hanger to the surface 8 to facilitate reentry of the well 12. In step 53, evacuation of the hydrocarbons 26 may be undertaken (if any are present in region 42). This step 53 may include attachment of the line 44 (if not already completed), activation of the vacuum 48, and opening of the valve 34 to begin evacuation of the hydrocarbons 26. In step 66, the connector 38 may be attached to the reentry system 56. Attachment of the connector 38 may include, for example, casing cuts of the reentry system 56 at the connection point 40 (e.g., to properly size the combined riser 20 and reentry system 56 to a length, such as a predetermined length) as well as affixing of the connector 38 (e.g., welding or other affixing techniques) to the reentry system 56 at the connection point 40 and in step 55, the BOP may be attached to the connector 38, to be used in ongoing program of work (i.e., decommission of the well 12).
This written description uses examples to disclose the above description to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Accordingly, while the above disclosed embodiments may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the embodiments are not intended to be limited to the particular forms disclosed. Rather, the disclosed embodiment are to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the embodiments as defined by the following appended claims.
Claims
1. A system, comprising:
- a plug configured to restrict release of hydrocarbons from a terminal end of an offshore riser by accumulating the hydrocarbons at the plug when the plug is disposed in an internal portion of the offshore riser and at a first vertical location of the offshore riser; and
- a vent configured to be disposed at a second vertical location, wherein the vent is configured to provide a path for the hydrocarbons to be released from the offshore riser.
2. The system of claim 1, comprising a valve configured to control a flow of the hydrocarbons passing though the vent.
3. The system of claim 2, comprising a vacuum configured to evacuate the hydrocarbons from the offshore riser via the vent.
4. The system of claim 3, comprising a connector configured to couple the vacuum to the vent.
5. The system of claim 4, wherein the connector comprises a stab connector.
6. The system of claim 1, comprising a connector coupled to the offshore riser at a connection point at a third vertical location of the offshore riser.
7. The system of claim 6, wherein the third vertical location is disposed above the first vertical location relative to a seafloor.
8. The system of claim 6, wherein the connector is configured to be coupled to a blowout preventer.
9. The system of claim 1, wherein the vent is disposed in the offshore riser below the first vertical location relative to a seafloor as the second vertical location.
10. The system of claim 1, wherein the vent is disposed in the plug as the second vertical location.
11. A system, comprising:
- a body comprising a terminal end and a second end, wherein the second end of the body is configured to be coupled to an offshore riser;
- a plug configured to restrict release of hydrocarbons from the terminal end of the body by accumulating hydrocarbons at the plug when the plug is disposed in an internal portion of the body and at a first vertical location of the body; and
- a vent configured to be disposed in the body at a second vertical location, wherein the vent is configured to provide a path for the hydrocarbons to be released from the offshore riser.
12. The system of claim 11, wherein the body comprises a connector disposed at the second end of the body.
13. The system of claim 12, wherein the connector is configured to engage with the offshore riser to couple the body to the offshore riser.
14. The system of claim 11, comprising a valve configured to control a flow of the hydrocarbons passing though the vent.
15. The system of claim 14, comprising a connector coupled to the terminal end of the body, wherein the connector is configured to be coupled to a blowout preventer.
16. The system of claim 11, wherein the vent is disposed in the body below the first vertical location relative to a seafloor as the second vertical location.
17. The system of claim 11, wherein the vent is disposed in the plug as the second vertical location.
18. A system, comprising:
- a plug configured to restrict release of hydrocarbons from a terminal end of an offshore riser by accumulating the hydrocarbons at the plug when the plug is disposed adjacent to the offshore riser and at a first vertical location; and
- a vent configured to be disposed at a second vertical location, wherein the vent is configured to provide a path for the hydrocarbons to be released.
19. The system of claim 18, wherein the plug is configured to be disposed directly adjacent to the offshore riser as the first vertical location.
20. The system of claim 18, wherein the plug is configured to be disposed directly adjacent a body, wherein the body comprises a terminal end and a second end, wherein the second end of the body is configured to be coupled to the offshore riser.
21. A method, comprising:
- disposing a plug adjacent to an offshore riser at a first vertical location to restrict release of hydrocarbons from a terminal end of the offshore riser by accumulating the hydrocarbons at the plug; and
- venting the hydrocarbons via a vent disposed at a second vertical location, wherein the vent is configured to provide a path for the accumulated hydrocarbons to be released.
Type: Application
Filed: Jul 22, 2019
Publication Date: Jan 30, 2020
Inventors: Christopher Scott Stewart (Cornelius, NC), Thomas Strenger Proehl (Houston, TX)
Application Number: 16/518,209