Patent Grant
9951576
The present application is generally related to running a mudline closure device (MCD), and in particular to a running tool and a running process for running an MCD and a high pressure wellhead to or near a seafloor in a single trip, and an associated lockdown tool and process.
A typical process of running an MCD involves a number of steps. To illustrate, a typical process may involve drilling a conductor hole to a desired depth and coupling a number of casings together to have a needed casing length. After the needed length of a casing is assembled, a high pressure wellhead is connected to the top joint of the casing. A running tool, designed for running the high pressure wellhead, is connected to the high pressure wellhead to run the high pressure wellhead to a conductor wellhead housing at the seafloor. To illustrate, a running string, which can consist of drill pipe or a thicker wall higher tensile strength pipe, may be attached to the running tool used to run the high pressure wellhead. The high pressure wellhead, along with the attached casing, is lowered to or near the seafloor where the high pressure wellhead is placed in the conductor wellhead.
After placement of the high pressure wellhead with the attached casing on the conductor wellhead housing, the casing is cemented in place by pumping cement down through the running string, where some of the cement returns to the sea floor on the outside of the casing. After the running tool used to run the high pressure wellhead is released from the high pressure wellhead and pulled from the seafloor back to the surface, and after the cement that is pumped down has time to harden, the MCD is run and connected to the high pressure wellhead that is seated in the conductor wellhead housing. The MCD is then pressure and function tested. The separate steps of running the high pressure wellhead and running the MCD, as well as the time for hardening of the pumped down cement, can take multiple days and can be expensive.
Further, a typical process of actuating a locking mechanism that is between the conductor wellhead housing and high pressure wellhead uses a lockdown tool that slips over the outside of the high pressure wellhead. To illustrate, after the lockdown tool is placed over the outside of the high pressure wellhead, tension is applied to the lockdown tool to latch and pre-load the high pressure wellhead to the conductor wellhead. The conductor wellhead housing and the high pressure wellhead are then held in place by the actuated lockdown mechanism. After the pre-loading process is completed, the lockdown tool is recovered to the surface (e.g., the offshore rig). Because the lockdown tool is placed over the top of the high pressure wellhead and then is slipped off the high pressure wellhead, the lockdown tool prevents running other equipment, such as an MCD, attached to the top of the high pressure wellhead in the same step as the running of the high pressure wellhead.
Thus, a running tool assembly, system, and process for running the MCD along with the high pressure wellhead and casing in a single trip can save time and reduce cost. Further, a lockdown tool and process that allow equipment that attaches to the high pressure wellhead to be run at the same time as the high pressure wellhead can save time and reduce cost.
The present application is generally related to running a mudline closure device (MCD), and in particular to a running tool and a running process for running an MCD and a high pressure wellhead to a seafloor in a single trip and an associated lockdown tool and process.
In an example embodiment, A lockdown tool for locking down a high pressure wellhead with a conductor wellhead housing includes a housing that includes a conductor wellhead housing facing surface designed to come in contact with a conductor wellhead housing positioned at or near a seafloor. The housing further includes a lockdown mechanism facing surface designed to come in contact with a lockdown mechanism that is between the conductor wellhead housing and a high pressure wellhead seated in the conductor wellhead housing. The housing also includes a wellhead facing surface having a profile that matches a profile of the high pressure wellhead formed on an outer surface of the high pressure wellhead. The lockdown tool further includes a piston positioned in a cavity of the housing and a hydraulic pressure port extending through a wall of the housing for applying hydraulic pressure by an external hydraulic pressure source into the cavity of the housing.
In another example embodiment, a method of actuating a lockdown mechanism positioned between a high pressure wellhead and conductor wellhead housing includes attaching a lockdown tool to a high pressure wellbore, where the lockdown tool is annularly positioned around the high pressure wellbore. The method further includes running the high pressure wellhead to a seafloor along with the lockdown tool and positioning the high pressure wellhead in a conductor wellhead housing positioned at the seafloor. The method also includes applying hydraulic pressure to a cavity of the lockdown tool.
In another example embodiment, an offshore running and preloading system includes a running tool assembly for running a high pressure wellhead and a mudline closure device (MCD) to or near a seafloor. The running tool assembly includes an upper pipe and a test plug release mechanism detachably coupled in the running tool assembly. The running tool assembly further includes an inner diameter isolation tool and a test plug designed to be attached to a high pressure wellhead. The running tool assembly also includes a lower pipe. The offshore running and preloading system further includes a lockdown tool for locking down the high pressure wellhead with a conductor wellhead housing. The lockdown tool includes a housing. The housing includes a conductor wellhead housing facing surface designed to come in contact with the conductor wellhead housing positioned at or near the seafloor. The housing further includes a lockdown mechanism facing surface designed to come in contact with a lockdown mechanism that is at least partially positioned between the conductor wellhead housing and a high pressure wellhead seated in the conductor wellhead housing. The housing also includes a wellhead facing surface having a profile that matches a profile of the high pressure wellhead formed on an outer surface of the high pressure wellhead. The lockdown tool further includes a piston positioned in a cavity of the housing and a hydraulic pressure port extending through a wall of the housing for applying hydraulic pressure by an external hydraulic pressure source into the cavity of the housing.
These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims.
Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The drawings illustrate only example embodiments and are therefore not to be considered limiting in scope. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or placements may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements.
The devices and methods of the present application include a running tool assembly for running, in a single trip, a high pressure wellhead and a mudline closure device (MCD) to a conductor wellhead housing that is, for example, at or near a seafloor. In some applications, an MCD may be used in conjunction with a blow-out-preventer (BOP). The MCD is typically attached to the top of high pressure wellhead and subsequently tested. The high pressure wellhead is positioned in a conductor wellhead housing that is at or near the seafloor. Running the high pressure wellhead and the MCD to the seafloor in a single run can reduce time and cost associated with typical multiple runs.
The devices and methods of the present application also include a hydraulically operated lockdown tool that exerts a pre-load stress on a conductor wellhead housing and a high pressure wellhead seated in the conductor wellhead housing. The lockdown tool can be used to actuate a lockdown mechanism (e.g., slips) that is between the high pressure wellhead and the conductor wellhead housing. Upon actuation of the lockdown mechanism by the lockdown tool, the lockdown tool may be removed. The lockdown mechanism maintains the desired stress state between the high pressure wellhead and the conductor wellhead housing connection. The lockdown tool assembly of the present application is positioned annularly around the high pressure wellhead and does not block the top of the high pressure wellhead, allowing other equipment, such as a MCD, to be run at or near the seafloor along with the high pressure wellhead, thus saving time and expense.
Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. One of ordinary skill in the art will appreciate that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
The present invention may be better understood by reading the following description of non-limitative embodiments with reference to the attached drawings wherein like parts of each of the figures are identified by the same reference characters. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, for example, a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, for instance, a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
Turning to the drawings,
In some example embodiments, the MCD 104 may be coupled to the high pressure wellhead 106. For example, the MCD 104 may be coupled to the high pressure wellhead 106 at an upper end portion of the high pressure wellhead 106. To illustrate, the high pressure wellhead 106 may include a profile 122 on an outer surface. For example, the profile 122 of the high pressure wellhead 106 may be a proprietary profile specific to a manufacturer of the high pressure wellhead 106. Alternatively, the profile 122 may be a standard profile that is commonly used by different manufacturers. The profile 122 of the high pressure wellhead 106 is designed to mate with a profile 120 on an inner surface of the MCD 104. For example, a lower end portion of the MCD 104 may be positioned annularly around the upper end portion of the high pressure wellhead 106 such that the profile 120 of the MCD 104 and the profile 122 of the high pressure wellhead 106 interlock with each other. In some alternative embodiments, the MCD 104 may be coupled to the high pressure wellhead 106 by other means as may be contemplated by those of ordinary skill in the art with the benefit of this disclosure.
In some example embodiments, the running tool assembly 102 includes an upper pipe 110, a test plug release mechanism 130, an inner diameter isolation tool 132, a test plug 114, and a lower pipe 112. The upper pipe 110 and the test plug release mechanism 130 may be coupled to each other, and the test plug release mechanism 130 and the inner diameter isolation tool 132 may be coupled the each other. To illustrate, a bottom end portion of the upper pipe 110 and a top end portion of the test plug release mechanism 130 may be detachably coupled to each other, and a bottom end portion of the test plug release mechanism 130 and a top end portion of the inner diameter isolation tool 132 may be detachably coupled to each other. The inner diameter isolation tool 132 and the test plug 114 may be coupled to each other, and the test plug 114 and the lower pipe 112 may be coupled to each other. To illustrate, a bottom end portion of the inner diameter isolation tool 132 and a top end portion of the test plug 114 may be detachably coupled to each other, and a bottom end portion of the test plug 114 and a top end portion of the lower pipe 112 may be detachably coupled to each other. In certain exemplary embodiments, the lower pipe 112 includes multiple small pipe sections (not shown) to make up the overall lower pipe 112.
In alternate embodiments, the test plug 114 may be positioned between the test plug release mechanism 130 and the inner diameter isolation tool 132. To illustrate, the test plug release mechanism 130 may be detachably coupled to bottom end portion of the upper pipe 110 and the top end portion of the test plug 114, and the inner diameter isolation tool 132 may be detachably coupled to the bottom end portion of the test plug 114 and the top end portion of the lower pipe 112.
In certain exemplary embodiments, the test plug release mechanism 130 is detachably coupled to the running tool assembly 102. In some embodiments, the upper pipe 110 may be detached from the running tool assembly 102 using the test plug release mechanism 130. The test plug release mechanism 130 may be constructed as a J-slot using a small turn and straight pull to disengage, threads in which torque and rotation is applied to disengage, shear pins in which tension and/or rotation is applied to disengage, a ball catcher sub in which pressure is applied to disengage, or a simple seal and seal bore arrangement in which straight tension is used to disengage, among examples as one skilled in the art would understand.
In certain exemplary embodiments, the inner diameter isolation tool 132 may be constructed as a ball catcher sub, in which a properly sized ball matched to the catcher sub dropped inside a running string (not shown) would land and be caught in the ball catcher sub and provide a pressure seal at the inner diameter isolation tool 132 to allow pressure to be applied above the inner diameter isolation tool 132 and above the test plug 114 to pressure test the MCD 104. In other embodiments, a dart could be used in place of the ball and the dart would be pumped to land in its properly sized catcher sub to provide the pressure isolation. In yet other embodiments, a spring loaded flapper valve could be used as the inner diameter isolation tool 132 in which an inner tube holds the flapper valve open until the test plug release mechanism 130 is activated and disengages, thereby the inner tube is retrieved with a top portion of the test plug release mechanism 130, among examples as one skilled in the art would understand.
As illustrated in
As understood by those of ordinary skill in the art, the MCD 104 allows for temporary disconnecting of the surface equipment (e.g., a rig) from a subsea well. For example, the surface equipment may be disconnected from the well by the MCD 104 for reasons such as bad weather conditions.
In general, the MCD 104 may have on board activation power and pressure testing capability to perform self-testing and/or accessibility to a remote operated vehicle (ROV) to perform such testing. As shown in
In some example embodiments, the test plug 114 may serve as a tension load support structure to support the downward load resulting from the upper pipe 110 and the lower pipe 112. In some alternative embodiments, the test plug 114 may just provide a pressure seal for the MCD 104 and another structure may be used to provide tension load support.
In some example embodiments, the running tool assembly 102 includes a launch tool 128 that includes one or more cement wiper plugs 124. The launch tool 128 can be coupled to the lower pipe 112. For example, the launch tool 128 may be coupled proximal to a bottom end portion of the lower pipe 112. After the system 100 of
The running tool assembly 102 may be constructed generally from steel and/or other suitable material as may be contemplated by those of ordinary skill in the art with the benefit of this disclosure. The test plug 114 may be constructed from a single structure or may be formed into an annular shape from two or more segments. As illustrated in
To illustrate, after a desired length of the casing 108 is assembled by screwing together multiple casings, the casing 108 is coupled to the high pressure wellhead 106 at the surface (e.g., offshore rig) as described above or at a factory. The MCD 104 may then be coupled to the high pressure wellhead 106. The running tool assembly 102 components may then be coupled together to form the running tool assembly at the surface or factory. The running tool assembly 102 may then be coupled to the high pressure wellhead 106.
Before running the MCD 104, the high pressure wellhead 106, and the casing 108 to or near the seafloor level using the running tool assembly 102, the running string 306 is coupled to the upper pipe 110. The running tool assembly 102 coupled to the running string 306 may then be used to run the MCD 104, the high pressure wellhead 106, and the casing 108 to or near the seafloor in a single trip, where the high pressure wellhead 106 is seated in a conductor wellhead housing 302.
As illustrated in
After running the MCD 104, the high pressure wellhead 106, and the casing 108 to or near the seafloor level using the running tool assembly 102 such that the high pressure wellhead 106 is seated in the conductor wellhead housing 302, cementing of the casing 108 may be performed by pumping down cement through the running string 306 and the running tool assembly 102 such that the cement moves in the direction of the arrows at the bottom of the casing 108. Darts or balls (not shown) may be used to launch the cement wiper plugs 124 from the launch tool 128 in performing the cementing operation. After the pumping down of cement through the running string 306, the running tool assembly 102, and casing 108 is completed, testing of the MCD 104 may be started immediately after the cement pumping is completed and the upper pipe 110 is released from the test plug 114. Because testing of the MCD 104 may be performed immediately after completion of cementing operations, significant time may be saved as compared to the typical process where the testing of the MCD 104 is performed after the running string 306 is recovered back to the surface equipment (rig) and an MCD is then run on the drilling riser or a cable.
At step 608, the method 600 includes running the casing, the MCD, and the high pressure wellhead together to or near the seafloor using the running tool assembly that is coupled to the high pressure wellhead. To illustrate, the casing 108, the MCD 104, and the high pressure wellhead 106 that are coupled, as described above, may be run to or near the seafloor. As described above, the running tool assembly 102 may be coupled to the high pressure wellhead 106 through the MCD 104. When the high pressure wellhead 106 is run to or near the seafloor, the high pressure wellhead 106 is positioned in a conductor wellhead housing positioned at or near the seafloor. The method 600 may also include attaching a running string such as the running string shown
In some example embodiments, after the casing 108, the MCD 104, and the high pressure wellhead 106 are run to or near the seafloor, testing of the MCD 104 may be performed as described above. Prior to testing of the MCD 104, cementing of the casing 108 is performed through the upper pipe 110 and lower pipe 112 of the running tool assembly 102. After cementing is performed and prior to testing the MCD 104, a ball or a dart may be dropped (e.g., from the rig) to the running tool assembly 102 through the running string 306, wherein the ball and the dart are sized to sit in and block an opening of the lower pipe 112 of the running tool assembly 102. After the ball or dart is positioned on the opening of the lower pipe 112 and prior to testing the MCD 104, the upper pipe 110 of the running tool assembly 102 is disconnected from the lower pipe 112 as described above.
The upper pipe 110 and the tension load support structure 704 may be coupled to each other, and the tension load support structure 704 and the middle pipe 708 may be coupled the each other. To illustrate, a bottom end portion of the upper pipe 110 and a top end portion of the tension load support structure 704 may be detachably coupled to each other, and a bottom end portion of the tension load support structure 704 and a top end portion of the middle pipe 708 may be detachably coupled to each other. The middle pipe 708 and the test plug release mechanism 130 may be coupled to each other. To illustrate, a bottom end portion of the middle pipe 708 and a top end portion of the test plug release mechanism 130 may be detachably coupled to each other. The inner diameter isolation tool 132 may be coupled to the test plug release mechanism 130 and the test plug 714 similar to how the inner diameter isolation tool 132 is coupled to the test plug release mechanism 130 and the test plug 114.
In exemplary embodiments, the tension load support structure 704 supports the downward load resulting from, for example, the sections of the running tool assembly 702 below the upper pipe 110. In certain embodiments, the tension load support structure 704 includes a port 710 for pressure equalization above and below the tension load support structure 704. In some example embodiments, the test plug 714 provides a pressure seal at a top of the high pressure wellhead 106. In the example embodiment of
In some example embodiments, the lockdown mechanism 804 is run to or near the seafloor using the running tool assembly 102 after attachment of the lockdown mechanism 804 to the high pressure wellhead 106 at the surface or at a factory. The lockdown tool 802 may also be run along with the high pressure wellhead 106 using the running tool assembly 102. For example, the lockdown tool 802 may be coupled to the high pressure wellhead 106 at the surface or at a factory. The lockdown tool 802 may be positioned on the conductor wellhead housing 302 when the high pressure wellhead 106 is run to or near the seafloor and seated in the conductor wellhead housing 302.
The lockdown tool 802 may include a hydraulic pressure port 806 to attach to a hydraulic pressure source. For example, a remote operated vehicle (ROV) 810 may be used to apply hydraulic pressure to the inside of the lockdown tool 802 via the hydraulic pressure port 806. For example, when hydraulic pressure is applied to the lockdown tool 802, a compressive stress is applied on the conductor wellhead housing 302 and a tensile stress is applied on the high pressure wellhead 106 to create a pre-loaded stress on the conductor wellhead housing 302 and the high pressure wellhead 106. As a result of the stress applied the lockdown tool 802, the lockdown mechanism 804 is actuated, thereby retaining the high pressure wellhead 106 and conductor wellhead housing 302 coupled to each other. For example, the lockdown mechanism 804 may include slips and/or other means to keep the high pressure wellhead 106 and the conductor wellhead housing 302 together.
After the lockdown mechanism 804 is actuated, the lockdown tool 802 may be left in place or it may be removed from the high pressure wellhead 106. For example, the lockdown tool 802 may be made from multiple segments and each segment may be removed, for example, by an arm coupled to ROV 810. To illustrate, the lockdown tool 802 may be made by attaching two half segments that together fit annularly around the high pressure wellhead 106. The two half segments may then be detached from each other to remove the lockdown tool 802. Alternatively, the lockdown tool 802 may be made from more than two segments that for an annular shape and that may be detached from each other to remove the lockdown tool 802 from the high pressure wellhead 106.
Because the lockdown tool 802 does not cover the top opening of the MCD 104, an ROV 810 and means other than a running tool may be used to remove components, such as test plug 114 after testing of the MCD 104 is completed. The ability to use an ROV as compared to a running tool may reduce time can cost associated with removing and recovering components such as the test plug 114.
In some example embodiments, the housing 902 includes a wellhead facing surface 914, a lockdown mechanism facing surface 916, and a conductor wellhead housing facing surface 918. The conductor wellhead housing facing surface 918 is designed to come in contact with the conductor wellhead housing 302. The lockdown mechanism facing surface 916 is designed to come in contact with the lockdown mechanism 804 that is at least partially positioned between the conductor wellhead housing 302 and the high pressure wellhead 106 seated in the conductor wellhead housing 302. The wellhead facing surface 914 may have a profile 920 that matches a profile of the high pressure wellhead 106 formed an outer surface of the high pressure wellhead 106 to attach the lockdown tool 802 to the high pressure wellhead 106. In some alternative embodiments, a slip arrangement may be used instead of matching profiles to attach the lockdown tool 802 to the high pressure wellhead 106.
In some example embodiments, the lockdown tool 802 includes a seal 910 positioned between the piston 906 and a wall of the housing 902 on one side of the housing 902. Another seal 912 may be positioned between the piston 906 and a wall on opposite side of the housing 902. The seals 910, 912 are positioned to prevent hydraulic fluid introduced into the cavity 902 of the lockdown tool 802 from reaching a space 922 above piston 906.
In some example embodiments, the cavity 904 may be filled with air or another gas at the surface or in a factory before the lockdown tool 802 is run to or near the seafloor. The ROV 810 or another equipment may be used to apply hydraulic pressure to the cavity 904 of the housing 902. The applied hydraulic pressure may result in a compressive stress on the conductor wellhead housing 302 because of the downward force exerted on a segment of the housing 902 that includes the conductor wellhead housing facing surface 918. A tensile stress may be exerted by the lockdown tool 802 on the high pressure wellhead 106 because of the upward force resulting from the lifting of the piston 906 due to the hydraulic pressure.
In some example embodiments, the housing 902 may include a first half housing segment and a second half housing segment that are coupled to each other to form annular shape of the housing 902/the lockdown tool 802. In some alternative embodiments, the housing 902 may include three or more housing segments that are coupled together to form an annular shape of the housing 902/the lockdown tool 802. The housing 902 and the piston 906 may be made from steel or another suitable material as may be contemplated by those of ordinary skill in the art with the benefit of this disclosure. For example, the housing 902 and the piston 906 may be made by one or more methods such as machining, welding, etc.
Although a particular shape of the lockdown tool 802 is shown in
As illustrated in
As illustrated in
Although some embodiments have been described herein in detail, the descriptions are by way of example. The features of the embodiments described herein are representative and, in alternative embodiments, certain features, elements, and/or steps may be added or omitted. Additionally, modifications to aspects of the embodiments described herein may be made by those skilled in the art without departing from the spirit and scope of the following claims, the scope of which are to be accorded the broadest interpretation so as to encompass modifications and equivalent structures. One of ordinary skill in the art will appreciate that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
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|---|---|---|---|
| 4653778 | Alandy | Mar 1987 | A |
| 5188180 | Jennings | Feb 1993 | A |
| 5791418 | Milberger | Aug 1998 | A |
| 6260624 | Pallini, Jr. | Jul 2001 | B1 |
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| Number | Date | Country | |
|---|---|---|---|
| 20170198541 A1 | Jul 2017 | US |
