Patent Grant
10125581
The present disclosure provides an apparatus and methods for installing and selectively retrieving a casing hanger locking device within a wellhead system during the bit run and retrieval operations.
Natural resources such as oil or gas residing in a subterranean formation can be recovered by drilling a wellbore that penetrates the formation. The drilling operation involves the use of a drill bit at the end of a drill string to cut through the ground and drill the wellbore. A drilling fluid may be circulated downwardly through the drill string and then upwardly through the wellbore to the surface. The drilling fluid may be used to, among other things, cool the drill bit, lubricate the rotating drill string to prevent it from sticking to the walls of the wellbore, and remove drill cuttings from the wellbore.
During the drilling operations, the wellbore passes through subterranean formations with a variety of geological characteristics. Many of these subterranean formations contain fluids, including water and hydrocarbons, known as formation fluids. The formation fluids often exist at high temperatures and pressures. In certain circumstances, the high temperatures and pressures in the subterranean formation lead to upward loads and/or forces that require the pressures of the formation fluids to be controlled.
In ideal circumstances, the pressures of the formation fluids may be controlled by balancing the pressure of the formation fluid with the hydrostatic pressure of a drilling fluid. The weight of the drilling fluid, which can be adjusted by adding weighting agents, is usually sufficient to control the subterranean pressure and prevent the upward loads.
The subterranean pressures can change, however, and sometimes these changes can be sudden and unpredictable. For example, if the drill bit penetrates a formation with a higher pressure, the hydrostatic pressure of the drilling fluid may not be sufficient to balance this increased pressure of the formation fluid. In certain instances, this can lead to a blowout. Blowouts lead to loss of pressure control and possible heat transfer of (uncontrolled) fluid. These aspects in turn lead to increased annulus pressure, thermal growth which leads to mechanical loads, and direct mechanical loads.
Steps must be taken to control the upward loads from the formation fluids in the subterranean formation and the wellbore during the drilling operation. If these steps are not taken, the upward load can unseat the casing hanger used in the wellbore. This may result in the possible failure of the casing hanger annulus seal, which can lead to further loss of pressure control. Unseating the casing hanger can also create mechanical interference with separate pressure control or containment devices. The failure to control the upward loads in the wellbore can lead to loss of operator control in the drilling operations, damage to the drilling equipment, and even injury to the personnel on site.
Mechanical locking devices are used to control the upward loads and prevent the upward travel of the casing hanger in a blowout condition or similar condition. The locking devices are typically installed at the top of the casing hanger at the wellhead. The locking devices are designed to resist upward loads so that the casing hanger does not travel upward through the wellbore even if the subterranean pressure spikes. Thus, even when subterranean fluids flow upward, the casing hanger remains locked in place and does not interfere with the pressure control and containment devices.
Locking devices can be difficult and expensive to use, however. For example, subsequent casing runs cannot be made with the locking device installed in the wellhead because the locking device interfaces with many of the same components with which the next casing hanger would interface. As a result, the locking device must be removed from the wellbore each time casing is added. Conventional locking devices require a dedicated trip to run and retrieve, and three total trips are required to use a conventional locking device. The first trip is typically a measurement trip to verify the position of the most previously installed casing hanger. The second trip is typically the installation of the locking device. And the third trip is typically the retrieval of the locking device. These trips can be substantial, particularly in subsea drilling operations, where the wellhead may be located thousands of feet below the ocean surface. Each trip requires dedicated tooling to perform the intended task, and at current rig rates, these operations become very expensive.
The present disclosure provides an apparatus and methods for installing and selectively retrieving a casing hanger locking device within a wellhead system during the bit run and retrieval operations.
An embodiment of the present disclosure is an apparatus comprising: a bit sub comprising a tong neck, a cylindrical portion below the tong neck, and at least one stabilizing fin below the cylindrical section, wherein the at least one stabilizing fin comprises a keyway; a casing hanger locking device comprising an annular structure and an expandable ring disposed around an upper portion of the annular structure, the casing hanger locking device disposed around the bit sub; an actuation sleeve that engages with the casing hanger locking device; and a selective retrieval collar comprising a segmented retrieval ring, wherein the selective retrieval collar is attached to the bit sub, the actuation sleeve, and the casing hanger locking device. Optionally, the selective retrieval collar is attached to the bit sub with a first plurality of sheer pins; the selective retrieval collar is attached to the casing hanger locking device with a second plurality of sheer pins; and the selective retrieval collar is attached to the actuation sleeve with the segmented retrieval ring. Optionally, the keyway comprises a tapered section. Optionally, the casing hanger locking device further comprises at least one key that interfaces with the at least one keyway. Optionally, the at least one stabilizing fin further comprises at least one groove. Optionally, the bit sub further comprises at least one load shoulder. Optionally, the segmented retrieval ring is configured to selectively engage the actuation sleeve by a special operational function.
Another embodiment of the present disclosure is an apparatus comprising: a bit sub comprising a tong neck, a cylindrical portion below the tong neck, and at least one stabilizing fin below the cylindrical section, wherein the at least one stabilizing fin comprises a keyway; a casing hanger locking device comprising an annular structure and an expandable ring disposed around an upper portion of the annular structure, the casing hanger locking device disposed around the bit sub; an actuation sleeve that engages with the casing hanger locking device; and a selective retrieval collar, wherein the selective retrieval collar is attached to both the bit sub and the casing hanger locking device. Optionally, the selective retrieval collar is attached to the bit sub with a first plurality of sheer pins; the selective retrieval collar is attached to the casing hanger locking device with a second plurality of sheer pins; and the selective retrieval collar is not attached to the actuation sleeve. Optionally, the keyway comprises a tapered section. Optionally, the casing hanger locking device further comprises at least one key that interfaces with the at least one keyway. Optionally, the at least one stabilizing fin further comprises at least one groove. Optionally, the bit sub further comprises at least one load shoulder.
Another embodiment of the present disclosure is a method comprising: lowering an apparatus into a wellbore using a drill string, wherein the apparatus comprises: a bit sub comprising a tong neck, a cylindrical portion below the tong neck, and at least one stabilizing fin below the cylindrical section, wherein the at least one stabilizing fin comprises a keyway, a casing hanger locking device comprising an annular structure and an expandable ring disposed around an upper portion of the annular structure, the casing hanger locking device disposed around the bit sub, an actuation sleeve that engages with the casing hanger locking device, and a selective retrieval collar, wherein the selective retrieval collar is attached to both the bit sub and the casing hanger locking device; setting the casing hanger locking device in place in the wellbore; detaching the bit sub from the selective retrieval collar and the casing hanger locking device; lowering the bit sub further into the wellbore using the drill string to facilitate further drilling operations; and removing the drill string and the bit sub from the wellbore, wherein the bit sub engages the selective retrieval collar and removes the selective retrieval collar from the wellbore. Optionally, the casing hanger locking device remains in the wellbore after the bit sub and the selective retrieval collar have been removed from the wellbore. Optionally, the selective retrieval collar comprises a segmented retrieval ring and wherein the selective retrieval collar is attached to the actuation sleeve. Optionally, the step of removing the drill string and the bit sub from the wellbore further comprises removing the casing hanger locking device from the wellbore. Optionally, the step of detaching the bit sub from the selective retrieval collar and the casing hanger locking device further comprises rotating the bit sub relative to the selective retrieval collar and the casing hanger locking device. Optionally, the at least one stabilizing fin further comprises at least one groove, and wherein the step of detaching the bit sub from the selective retrieval collar and the casing hanger locking device further comprises at least one lock segment from the at least one groove. Optionally, the bit sub further comprises at least one load shoulder, and wherein the step of removing the drill string and the bit sub from the wellbore further comprises contacting the selective retrieval collar with the at least one load shoulder.
The features and advantages of the present invention will be readily apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the invention.
These drawings illustrate certain aspects of some of the embodiments of the present invention, and should not be used to limit or define the invention.
While embodiments of this disclosure have been depicted, such embodiments do not imply a limitation on the disclosure, and no such limitation should be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.
The present disclosure provides an apparatus and methods for installing and selectively retrieving a casing hanger locking device within a wellhead system during the bit run and retrieval operations. This can save effort, time, and expense over the prior art locking devices that require dedicated trips to remove them from the wellbore each time a new casing section is added.
In certain embodiments, the apparatus of the present disclosure is an assembly that comprises three major components. The first component is a Casing Hanger Locking Device. The Casing Hanger Locking Device is the component of the apparatus that serves as the locking device and can resist upward loads. The Casing Hanger Locking Device may comprise an actuation sleeve. The second component is a Bit Sub. The Bit Sub is attached directly to the drill string and connects the apparatus of the present disclosure to the drill string. The third component is a Selective Retrieval Collar. The Selective Retrieval Collar is attached to both of the other components and provides for the selective retrieval or installation of the Casing Hanger Locking Device.
Illustrative embodiments of the present disclosure are described in detail below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiments, 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 details of various illustrative embodiments will now be described with reference to the figures.
In
As shown in
The interior surface of the upper end of the Casing Hanger Locking Device 100 may have an upper shear pin groove 116a and a lower sheer pin groove 116b. The upper shear pin groove 116a and a lower sheer pin groove 116b are configured to engage sheer pins connected to the Selective Retrieval Collar 300. The lower side of the upper shear pin groove 116a and a lower sheer pin groove 116b may be beveled to allow the Selective Retrieval Collar 300 to move in a downward direction relative to the Casing Hanger Locking Device 100 without breaking the sheer pins. The interior surface of the upper end of the Casing Hanger Locking Device 100 may also have a groove 118. Casing Hanger Locking Device 100 also includes a C-ring 120.
The mid-section of the Casing Hanger Locking Device 100 includes a plurality of keyway slots 132 that extend through the wall of the Casing Hanger Locking Device 100. The keys 134 in the keyway slots 132 have a stop shoulder 136 on them to prevent them from passing through the keyway slot 132. These keys 134 are spring loaded inward. In some embodiments, the keys 134 may be square. As described below in more detail, the keys 134 may be used to attach the Casing Hanger Locking Device 100 to the Bit Sub 200.
The lower end of the Casing Hanger Locking Device 100 is designed to rest on the casing hanger and extends into the bowl of the casing hanger (not shown in
As noted earlier,
As shown in the exemplary embodiment of
As further shown in
In the embodiment of
Depending on whether the operator wishes to retrieve the Casing Hanger Locking Device 100 (as discussed below), the Selective Retrieval Collar 300 may take the form of either of two configurations. In the first configuration, Selective Retrieval Collar 300 includes a high strength segmented retrieval ring 350. In the second configuration, the Selective Retrieval Collar 300 does not include the high strength segmented retrieval ring 350.
The present disclosure in some embodiments include methods for using the apparatus of the present disclosure to carry out a variety of drilling operations. During drilling operations, the apparatus of the present disclosure is connected to the drill string. In certain embodiments, the apparatus of the present disclosure may be connected to the drill string above the drill bit. For example, the Bit Sub 200 may be connected to the drill string via industry-standard API tool joints. A person of ordinary skill in the art, with the benefit of this disclosure, would understand how to connect the apparatus to the drill string for the desired operations.
In certain embodiments, the apparatus of the present disclosure may be introduced into the wellbore as part of the drill string. The entire apparatus, including the Casing Hanger Locking Device 100, the Bit Sub 200, and the Selective Retrieval Collar 300, may be lowered into the wellbore according to conventional methods. For example, the drill string may be run into the wellbore.
Placing the Casing Hanger Locking Device:
When the apparatus of the present disclosure reaches the level of the casing hanger, the Casing Hanger Locking Device 100 may be locked into place. In an embodiment, the assembly is lowered with the drill string into the wellbore. When the assembly reaches the casing hanger, the Casing Hanger Locking Device 100 is unable to move any further downhole. However, the spherical nose pins 156 contact the casing hanger. The spherical nose pins 156 are depressed which causes the sheer pins 154 to break and releases the lock segments 152. The lock segments 152 disengage from the machined grooves 244 in the Bit Sub 200 which allows the Bit Sub 200 to move downward relative to the Casing Hanger Locking Device 100.
To set the Casing Hanger Locking Device 100 in place, the Bit Sub 200, the Selective Retrieval Collar 300, and the actuation sleeve 400 continue to move downhole. Sheer pins attaching the actuation sleeve 400 to the Casing Hanger Locking Device 100 break, allowing the actuation sleeve 400 to move relative to the Casing Hanger Locking Device 100. The actuation sleeve 400 moves down and forces the expandable ring 112 in an outward axial direction. This permits the load shoulders 114 to engage the profile in the wellhead, setting the Casing Hanger Locking Device 100 in place.
The Selective Retrieval Collar 300 remains connected to the Casing Hanger Locking Device 100 and the Bit Sub 200 disengages from both components. In particular, the sheer pins (in holes 310 Selective Retrieval Collar 300 and the drilled holes 224 of the Bit Sub 200) break and allow the Bit Sub 200 to move downward relative to the Selective Retrieval Collar 300.
As the Bit Sub 200 moves downward, it releases the load transfer pins 320. The C-ring 120 that is biased inwardly moves into the groove 325 on the Selective Retrieval Collar 300. If the Selective Retrieval Collar 300 is loaded upwardly, this load goes into these interfaces rather than the spring loaded shear pins 340.
At this point, an over-pull may be performed to ensure that the Casing Hanger Locking Device 100 is properly set. The operator may continue to trip in until his weight indicator shows he has tagged the bit sub keyway 242 on the square keys 134 in the Casing Hanger Locking Device 100. At this point an over-pull may be performed to ensure that the Casing Hanger Locking Device 100 is properly set.
The operator may then perform a rotation to completely disengage the Bit Sub 200 from the Casing Hanger Locking Device 100. Rotating the Bit Sub 200 rotates the stabilizing fin 240 relative to the square keys 134. This rotation allows the square keys 134 to be removed from the keyway 242, for example, by passing over the tapered section 243. As the stabilizing fin 240 retracts the square key 134 from the keyway 242, a c-ring 138 snaps into a groove on the square key's rod section. This will not allow the key to re-enter the bore of the Casing Hanger Locking Device 100. This completes the placement of the Casing Hanger Locking Device 100.
Following the placement of the Casing Hanger Locking Device 100, the drill string, including the drill bit and the Bit Sub 200, are free to continue running down the wellbore. Therefore, drilling operations may continue after the Casing Hanger Locking Device 100 has been placed. When the Casing Hanger Locking Device 100 is locked into place, it is capable of resisting upward loads on the casing. This ensures that the well is kept under control if the drill bit penetrates a subterranean formation with increased temperature and pressure.
At some point, the operator may wish to remove the drill string from the wellbore. For example, the operator may need to change the drill bit or use a different tool. The drill string including the Bit Sub 200 may be removed from the wellbore according to conventional methods. According to embodiments of the present disclosure, the Casing Hanger Locking Device 100 may be selectively retrieved or left behind when the Bit Sub 200 reaches the level of the wellbore where it has been placed. In particular, and as discussed below, Bit Sub 200 will always retrieve Selective Retrieval Collar 300 but it will either retrieve or leave the Casing Hanger Locking Device 100 depending on how the Selective Retrieval Collar 300 is configured.
The Casing Hanger Locking Device 100 may be selectively retrieved from the wellbore or left behind depending on the goal of the operator. For example, the Casing Hanger Locking Device 100 may be retrieved from the well bore under normal operations or, for example, when an additional casing is installed in the well bore. For example, an operator may retrieve the Casing Hanger Locking Device 100 when drilling operations are believed to be short enough to remove the locking device in preparation for subsequent casing hanger installation. Alternatively, the Casing Hanger Locking Device 100 may be left in the wellbore when the well bore needs to be sealed for a period of time. An operator may leave the Casing Hanger Locking Device 100 when, for example, the drilling operations are believed to be long enough to necessitate a drill bit replacement, there is possible inclement weather during drilling operations that would require a disconnect from the wellhead, or there are other reasons requiring temporary abandonment between drilling and production operations.
Whether the Casing Hanger Locking Device 100 is retrieved on the same trip or left behind is determined by the configuration of Selective Retrieval Collar 300. As explained in more detail below, when retrieving the Casing Hanger Locking Device 100, the operator will select the configuration of Selective Retrieval Collar 300 that includes a segmented retrieval ring 350. The row of pockets 340 is loaded with spring loaded shear pins. This arrangement will allow the Casing Hanger Locking Device 100 to be carried to the surface. When leaving the Casing Hanger Locking Device 100, the operator will select the configuration of Selective Retrieval Collar 300 that does not include a segmented retrieval ring 350 and the row 340 is loaded with spring loaded sheer pins.
Retrieving the Casing Hanger Locking Device:
In one configuration, the apparatus of the present disclosure may be used to retrieve the Casing Hanger Locking Device 100. In this first configuration, the Selective Retrieval Collar 300 is connected to the actuation sleeve 400 through the segmented retrieval ring 350. This ensures that the Selective Retrieval Collar 300 remains connected to the actuation sleeve 400. The row 340 that connects the Selective Retrieval Collar 300 to the Casing Hanger Locking Device 100 is loaded with spring loaded sheer pins.
As the Bit Sub 200 is removed from the well bore and pulled through the assembly, it tags out on the Selective Retrieval Collar 300. In particular, the shoulder 222 engages the Selective Retrieval Collar 300. The Selective Retrieval Collar 300 is connected to the actuation sleeve 400 through the segmented retrieval ring 350, and as a result, this mechanical action pulls on the actuation sleeve 400, which pulls on the Casing Hanger Locking Device 100. The Selective Retrieval Collar 300 is connected to the Casing Hanger Locking Device 100 with spring loaded sheer pins. The spring loaded sheer pins break, which permits the actuation sleeve 400 to be lifted sufficiently high enough to disengage the expandable ring 112 and unlock the Casing Hanger Locking Device 100 from the mating wellhead profile. In certain embodiments, additional shear pins (not shown) may also be used. Continuing to lift pulls on the Bit Sub 200, which pulls on the Selective Retrieval Collar 300, which pulls on the actuation sleeve 400, and which engages the Casing Hanger Locking Device 100 via a shoulder and removes it from the wellhead.
In certain embodiments, the apparatus of the present disclosure may be configured to permit the operator to determine whether to retrieve the Casing Hanger Locking Device 100 on the fly. In these embodiments, the Selective Retrieval Collar 300 may be provided with a segmented retrieval ring 350 as discussed above. However, in these embodiments, segmented retrieval ring 350 may be made passive and triggered to engage the actuation sleeve 400 by a special operational function. If the operational function is performed after the apparatus is deployed, the segmented retrieval ring 350 may engage the actuation sleeve 400 (to retrieve the Casing Hanger Locking Device 100). On the other hand, if the operational function is not performed after the apparatus is deployed, the segmented retrieval ring 350 will not engage the actuation sleeve 400 (to leave the Casing Hanger Locking Device 100 behind).
Leaving the Casing Hanger Locking Device:
In another configuration, the apparatus may be used to retrieve only the Bit Sub 200 and Selective Retrieval Collar 300. In this second configuration, a Selective Retrieval Collar 300 without a segmented retrieval ring 350 is selected, such that the Selective Retrieval Collar 300 is not connected to the actuation sleeve 400. This allows the Selective Retrieval Collar 300 to separate from the actuation sleeve 400. The row 340 that connects the Selective Retrieval Collar 300 to the Casing Hanger Locking Device 100 is loaded with spring loaded sheer pins. Spring loaded sheer pins are used so that a positive indication is given when the Selective Retrieval Collar 300 disengages from the Casing Hanger Locking Device 100.
As the Bit Sub 200 is pulled through the assembly, it tags out on the Selective Retrieval Collar 300, which pulls on the actuation sleeve 400, which pulls on the Casing Hanger Locking Device 100. The Selective Retrieval Collar 300 is pulled with sufficiently high force to shear the pins which attached it to the Casing Hanger Locking Device 100. When the sheer pins break, neither the Bit Sub 200 nor the Selective Retrieval Collar 300 is connected, either directly or indirectly, to the Casing Hanger Locking Device 100. Continuing to lift removes only the Bit Sub 200 and the Selective Retrieval Collar 300 from the wellhead.
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Moreover, the indefinite articles “a” or “an”, as used in the claims, are defined herein to mean one or more than one of the element that it introduces. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4836288 | Wester | Jun 1989 | A |
| 5105888 | Pollock | Apr 1992 | A |
| 9506329 | Massey | Nov 2016 | B2 |
| 9689229 | Hanson | Jun 2017 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20170175496 A1 | Jun 2017 | US |
