This disclosure relates generally to oilfield equipment and more particularly to a bi-directional wellhead annulus packoff and an associated method for energizing and de-energizing the wellhead annulus packoff.
Hangers may be configured with an external lockdown ring that is located above or below a wellhead annulus packoff. The wellhead annulus packoff can be locked down below the wellhead annulus packoff. However, such a configuration may create a debris pocket for accumulation of matter therein. A debris pocket can impede an ability of the lockdown ring to engage in a housing or hanger. Further, hangers may be configured with an external lockdown ring above the wellhead annulus packoff with some advantages, such as to allow for a debris pocket below the wellhead annulus packoff to accommodate debris. This, however, transfers a hanger lockdown load through the wellhead annulus packoff, which can cause issues for seal components in the wellhead annulus packoff. The wellhead annulus packoff can be locked independently to a neck of the hanger to prevent shuttling relative to the hanger. The timing and mechanism may be an issue while setting the wellhead annulus packoff, and particularly setting a seal lockdown ring and a hanger lockdown ring, in an annular envelop between the hanger neck and a wellhead housing bore.
In at least one embodiment, a method to be used for energizing a wellhead annulus packoff is disclosed. The method includes providing at least one seal element, a seal lockdown energizing ring, a hanger lockdown energizing ring, a seal lockdown ring, and a hanger lockdown ring as seal components for the wellhead annulus packoff. The method also includes providing one or more mechanical conditional operators adapted to disengage during energizing of the wellhead annulus packoff. A further feature of the method includes enabling a first energizing force to cause, through the seal lockdown energizing ring, the at least one seal element and the seal lockdown ring to be energized. The method also includes enabling a second energizing force to cause, through the hanger lockdown energizing ring, the hanger lockdown ring to be energized.
In at least one embodiment, a further method to be used for de-energizing a wellhead annulus packoff is disclosed. The method is applied to the wellhead annulus packoff that includes at least one seal element, a seal lockdown energizing ring, a hanger lockdown energizing ring, a seal lockdown ring, a hanger lockdown ring, and one or more mechanical conditional operators in a disengaged state with the wellhead annulus packoff in a fully energized stage. The method includes enabling a first de-energizing force through the hanger lockdown energizing ring. The first de-energizing force is to cause the hanger lockdown ring to be de-energized. A further step in the method is for enabling a second de-energizing force through the seal lockdown energizing ring. The second de-energizing force is to cause the at least one seal element and the seal lockdown ring to be de-energized.
In at least one embodiment, a wellhead annulus packoff is disclosed. The wellhead annulus packoff includes at least one seal element, a hanger lockdown ring, a seal lockdown ring, and one or more mechanical conditional operators, where the at least one seal element adapted to be energized with a first energizing force and with the one or more mechanical conditional operators being engaged, where the seal lockdown ring is adapted to be energized with the first energizing force and with the one or more mechanical conditional operators being disengaged, and where the hanger lockdown ring is adapted to be energized with a second energizing force.
Various embodiments in accordance with the present disclosure will be described with reference to the drawings, in which:
In the following description, various embodiments will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the embodiments may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described.
Various other functions can be implemented within the various embodiments as well as discussed and suggested elsewhere herein. In at least an aspect, the present disclosure is to a system and a method for a wellhead annulus packoff, in accordance to at least one embodiment.
In at least one embodiment, a wellhead annulus packoff that embodies a single trip bi-directional and integral seal with a hanger lockdown ring is disclosed. The single trip is in reference to seal components being run and installed in a single operation. Such a single trip may use a first energizing force for energizing a seal element and a seal lockdown ring and may use a second energizing force to energize a hanger lockdown ring. The single trip, therefore, may include two setting strokes, representing the two energizing forces, in a single operation. The two energizing forces are applied to both energize and retain the at least one seal element and the lockdown rings in an installed position.
In at least one embodiment, such a wellhead annulus packoff simplifies operational tooling required to set or energize a wellhead annulus packoff. The adaption discussed herein also allows the at least one seal element and hanger to be locked down from above the seal element and allows for improved debris tolerance and installation reliability for a wellhead annulus packoff. In a commercial setting, the adaption enables simultaneous setting and locking of a seal, in place, in a single operation. For example, the present adaption is able to engage both, the seal element and the seal lockdown ring in a single operation, without using wickers. In at least one embodiment, engagement and energizing are interchangeably used herein unless otherwise indicated, such as by an engagement feature first followed by an energizing feature.
In at least one embodiment, a wellhead annulus packoff herein is a bi-directional metal-to-metal (MS) annulus seal that includes two annular seals elements that isolate an annular space between a wellhead housing and a hanger, such as the neck of a hanger. At least one MS seal forms an annulus barrier between a volume above and a volume below within the annular space. Further, at least one seal element may be stacked in series to allow for a test volume between the at least one seal element to be formed for an external well barrier integrity testing.
In at least one embodiment, the wellhead annulus packoff is also referred to as a seal that may be characterized in two body portions. A lower seal body includes at least one seal element and an upper seal body that includes a seal lockdown ring, a seal lockdown energizing ring, a hanger lockdown ring, and a hanger lockdown energizing ring. The lockdown rings of the upper seal body represents a lockdown ring retention mechanism to lock the upper seal body to the neck of the hanger and to lock the hanger to the housing. This is so that a hanger-to-housing load may be transferred to the housing. The upper seal body may engage teeth of the seal lockdown ring into a matching lockdown profile in the hanger neck.
A mechanical conditional operator, such as a shear pin, a shear ring, a buckling member, a tensile coupon, or a spring-loaded member allows a setting or energizing force to be transferred through the upper seal body into the lower seal body to energize the at least one seal element. As part of the seal element being energized, the mechanical conditional operator changes the load path to set or energize the seal lockdown ring. For example, the mechanical conditional operator is adapted to disengage, such as by a change to its state or by shearing. Changes in state or shearing may include changes in a shape by collapsing, by buckling or by stressing or tensing. As such, when engaged, there may be a first load path through a mechanical conditional operator, but when disengaged, there may be a second load path through other seal components.
The at least one seal element forms an integrated seal. Once the at least one seal element is energized in place, a further feature herein is to energize other seal components of the wellhead annulus packoff by setting or energizing an external or a hanger lockdown ring to lock the hanger in the wellhead housing. In at least one embodiment, such an adaptation or configuration allows for vastly improved debris tolerance, because a debris pocket can be formed below the wellhead annular packoff, which can accommodate the debris.
The one or more mechanical conditional operators 116A, 118B, 122 are adapted to disengage following energizing of the at least one seal element and prior to energizing of the seal lockdown ring, using a first energizing force applied through the seal lockdown energizing ring 108. For example, when the mechanical conditional operator is a shear ring or a shear pin, the shear ring or shear pin is adapted to shear upon a first energizing force reaching a certain load. Further, the hanger lockdown ring 106 is adapted to be energized using a second energizing force through the hanger lockdown energizing ring 104, once the seal lockdown ring has been energized.
In
The association of the seal lockdown energizing ring 132 and the upper seal energizing ring 134 (the semi-circular members of such rings) here is understood to be so that the ridge 134A caught within the railings 132A, 132B may be used to lift the upper seal energizing ring during retrieval of the wellhead annulus packoff.
The transfer mechanism, therefore, holds two or more seal components together and helps in retrieval of such seal components. However, the transfer mechanism may not transfer energizing forces during energizing. The mechanical conditional operators may transfer portions of the energizing forces through one or more seal components. In at least one embodiment, some seal components may not have association with a mechanical conditional operator but may only have a transfer mechanisms associated therewith. For example, other than a seal lockdown energizing ring and an upper seal energizing ring, some seal components may only have a transfer mechanisms associated therewith.
In at least one embodiment, the association together of the seal lockdown energizing ring 152 and the upper seal energizing ring 154 also allows relative movement between these two parts. Such relative movement (or stroke) may be limited by a gap between a surface of the ridge 136A and a corresponding mating surface 136B. As such, these two parts may be held together, but can move by a predetermined amount that may be limited by a gap defined between the two interfacing surfaces 136A, 136B. In at least one embodiment, a state of the mechanical condition operator is related to a capability of a relative movement enabled between the seal lockdown energizing ring 152 and the upper seal energizing ring 154. For example, when a shear pin that associates together the seal lockdown energizing ring 152 and the upper seal energizing ring 154, is not sheared, there is no relative movement allowed between these two seal components and hence applied load from an energizing force is transferred through the seal. When the shear pin has sheared, these two seal components can move relative to each other and the applied load to a seal lockdown energizing ring 152, from the energizing force, causes at least the seal lockdown ring 186 to be energized.
In at least one embodiment, a second energizing force (downward component of the reference arrow 208B) may be enabled to cause, through a hanger lockdown energizing ring 224, a hanger lockdown ring 222, to be energized. The first energizing force 208A may be applied as a single continuous stroke or force through the stages illustrated in
For removal of the wellhead annulus packoff 200A, a first de-energizing force (upward component of the reference arrow 208B) may be applied to cause the hanger lockdown ring 222 to be de-energized. Still further, a second de-energizing force or pulling force (upward component of the reference arrow 208A) may be provided to the seal lockdown energizing ring 210 during removal of the wellhead annulus packoff 200A, in accordance to at least one embodiment. At least the second de-energizing force (upward component 208A) is applied through the stages illustrated in
In at least one embodiment, the lower seal energizing ring 220 is adapted to sit on a shoulder 206A of the hanger 206. Further, a seal element 216 includes legs, such as an outer bottom leg 216C, that may be subsequently energized by the lower seal energizing ring 220. Further, the lower seal energizing ring 220 may include a straight surface or profile 220B or a toothed surface or profile to engage with a mating profile provided for a hanger 206. Furthermore a seal element 216 may include inner legs 216D that are distinct from the outer bottom leg. In at least one embodiment, the inner legs 216D provided sealing against the hanger 206 when the seal element 216 moves down relative to the hanger 206.
In at least one embodiment, the seal lockdown ring 218 is illustrated with a toothed surface or profile 218A to mate with a matching profile 206B provided for a hanger 206. Similarly, the hanger lockdown ring 222 may include a toothed surface or profile 222A to mate with a matching profile 204A provided for a housing 204. The first energizing force 208A transfers 212 through the seal lockdown energizing ring 210, the mechanical conditional operator 214A, and the upper seal energizing ring 214. Subsequently, a seal element 216 receives the first energizing force 208A from the upper seal energizing ring 214.
In at least one embodiment, part of the first energizing force 208A is transferred via a mechanical conditional operator (214A or 176), such as a shear pin. The conditional operator 214A or 176 may change state once the seal element 216; 182 is fully energized, and then allows the seal lockdown ring 218 to be set or energized as influenced in part by the second stage 208A of a continuous first energizing force or stroke, which is also illustrated in
The first energizing force 322 causes the at least one seal element 312 to be energized first, with the lower seal energizing ring 316, by the first energizing force passing through the seal via one or more transfer mechanisms. This is part of a first stage of energizing of the wellhead annulus packoff 300A. Once the seal element 312 is fully energized (which is also illustrated in
The lower seal energizing ring 316 may be associated with a mechanical conditional operator 314B that is also associated with the seal element 312. In the first stage of the partly energized state, the mechanical conditional operator 314B associated between the lower seal energizing ring 316 and the seal element 312 may be caused to shear or change state in other ways so that one of the at least one seal element may slide against the lower seal energizing ring 316 during energizing of the wellhead annulus packoff 300A. In
In at least one embodiment, the shearing of the mechanical conditional operator 314B enables a slot or space 312B to be formed. Further, a surface or shoulder 312C of the seal element 312 is exposed and may be used during de-energizing to allow the seal element 312 support a transfer mechanism 314A during retrieval of the lower seal energizing ring 316 by a pulling force that transfers to the seal element as discussed in at least in
In at least one embodiment, inner legs 312E of a seal element 312 form a seal against a neck of a hanger as the seal element 312 moves down during energizing. In a landed position, such as illustrated in
In at least one embodiment,
Then, the upper seal energizing ring 408 closes a previously indicated void (318 in
In at least one embodiment,
In at least one embodiment, a third one 408C of the one or more mechanical conditional operators, also illustrated as reference numeral 176 in
Particularly, with the lower seal components being energized and offering support from underneath to the upper seal components, the first energizing force 502 cannot cause further movements to the lower seal components and instead causes the seal lockdown energizing ring 504 to settle between the seal lockdown ring 506 and the upper seal energizing ring 508. A finger 504A of the seal lockdown energizing ring may energize the seal lockdown ring 506 with support from the upper seal energizing ring 508 and another finger 504B of the seal lockdown energizing ring 504. A finger 504A of the seal lockdown energizing ring 504 causes inward radial movement (such as, towards an axis of a wellbore) of the seal lockdown ring 506. This allows the seal lockdown ring 506 to be driven towards engagement with a matching profile on a neck of the hanger. The seal lockdown ring is made to sit within a matching profile of the hanger.
The removal of radial support, previously provided by at least a finger of the seal lockdown energizing ring 804 to the seal lockdown ring 806 can cause an outwards bias of the seal lockdown ring 806 to activate and enables the seal lockdown ring 806 to retract away from a matching profile in the hanger. The second de-energizing force 802 also allows a flange of the upper seal energizing ring 810 to catch within a narrow neck between the fingers of the seal lockdown energizing ring in the area 808 illustrated in
The method 1200 includes enabling (1206) a first energizing force to cause, through the seal lockdown energizing ring, the at least one seal element to be energized. A verification step 1208 is performed to verify that the seal element is engaged or energized, otherwise the prior enabling (1206) step may be repeated. Upon successful verification in step 1208, another step in the method 1200 includes causing (1210) one or more mechanical conditional operators to disengage, such as to become sheared or to change state, as the first energizing force is continued.
With the one or more mechanical conditional operators disengaged, such as be sheared or change in state, a further step in the method 1200 includes enabling (1212) the first energizing force to continue further to cause, through the seal lockdown energizing ring, the seal lockdown ring to be energized. A verification step 1214 may occur to ensure that the seal lockdown ring is energized. Upon positive verification, step 1216 may occur; otherwise, step 1212 may be repeated.
The method 1200 includes enabling (1216) a second energizing force to cause, through the hanger lockdown energizing ring, the hanger lockdown ring to be energized. In at least one embodiment, one or more of the steps in the method 1200 may be performed in a combined manner with a built-in verification, such as steps 1206 to 1212 may be performed together with the verification step 1208 as a single continue stroke using the first energizing force and using load limits mechanically built into the one or more mechanical conditional operators.
The method 1200 may include further steps or sub-steps for associating the one or more mechanical conditional operators with the at least one seal element or the seal lockdown energizing ring. The method 1200 may include further steps or sub-steps for causing the one or more mechanical conditional operators to shear or change state as part of the disengagement during energizing of the wellhead annulus packoff.
The method 1200 may include further steps or sub-steps for enabling the first energizing force to be applied as a single continuous force to the seal lockdown energizing ring. Further, a first part of the single continuous force causes the at least one seal element to be energized. A second part of the single continuous force causes the one or more mechanical conditional operators adapted to be disengaged. A third part of the single continuous force causes the one or more mechanical conditional operators adapted to disengage causes the seal lockdown ring to be energized.
The method 1200 may include further steps or sub-steps for enabling, using the first energizing force, the at least one seal element (such as, the bottom inner leg, top inner leg, and bottom outer leg of the seal element) to be energized through a first relative movement against the lower seal energizing ring. The first relative movement may be enabled by a disengagement of a first one of the one or more mechanical conditional operators. The method 1200 may include further steps or sub-steps for enabling, using the first energizing force, the at least one seal element to be energized through a second relative movement against an upper seal energizing ring. The second relative movement may be enabled by a disengagement of a second one of the one or more mechanical conditional operators.
The method 1200 may include further steps or sub-steps for enabling one of the one or more mechanical conditional operators to transfer at least one part of the first energizing force, through an upper seal energizing ring, to the at least one seal element. The at least one seal element can energize with a lower seal energizing ring in a first stage of the energizing of the wellhead annulus packoff. The method 1200 may include further steps or sub-steps for enabling the seal lockdown energizing ring to transfer at least another part of the first energizing force to an upper seal energizing ring, with the one of the one or more mechanical conditional operators being disengaged. The at least one seal element can energize with the upper seal energizing ring in a second stage of the energizing of the wellhead annulus packoff.
The method 1200 may include further steps or sub-steps for enabling, using the first energizing force, the upper seal energizing ring to energize with the at least one seal element and with the seal lockdown ring in a third stage of the energizing of the wellhead annulus packoff. The method 1200 may include further steps or sub-steps for enabling, using the second energizing force, the hanger lockdown energizing ring to energize with the hanger lockdown ring and with the seal lockdown energizing ring to provide a fully energized stage of the wellhead annulus packoff.
When provided (1252) with such a wellhead annulus packoff that is in a fully energized stage, the method includes enabling (1254) a first de-energizing force through the hanger lockdown energizing ring. The first de-energizing force can cause the hanger lockdown ring to be de-energized. A verification step 1256 verifies that the hanger lockdown ring is de-energized. The prior enabling step 1254 may be otherwise repeated. Upon successful verification, a further enabling (1258) step may be performed for a second de-energizing force through the seal lockdown energizing ring. The second de-energizing force can cause the seal lockdown ring to be de-energized and can cause the at least one seal element to be de-energized.
The method 1250 may include further steps or sub-steps for enabling, using first shoulders or surfaces, transfer of the second de-energizing force from the seal lockdown energizing ring to the upper seal energizing ring. The method 1250 may include further steps or sub-steps for enabling, using second shoulders or surfaces, transfer of the second de-energizing force, from the upper seal energizing ring to the at least one seal element. Further, the method 1250 may include further steps or sub-steps for enabling, using third shoulders or surfaces, transfer of the second de-energizing force, from the seal element to a lower seal energizing ring so that the wellhead annulus packoff is de-energized.
It should be appreciated that embodiments herein may utilize one or more values that may be experimentally determined or correlated to certain performance characteristics based on operating conditions under similar or different conditions. The present disclosure 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 disclosure 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 disclosure disclosed herein and the scope of the appended claims.
While techniques herein may be subject to modifications and alternative constructions, these variations are within spirit of present disclosure. As such, certain illustrated embodiments are shown in drawings and have been described above in detail, but these are not limiting disclosure to specific form or forms disclosed; and instead, cover all modifications, alternative constructions, and equivalents falling within spirit and scope of disclosure, as defined in appended claims.
Terms such as a, an, the, and similar referents, in context of describing disclosed embodiments (especially in context of following claims), are understood to cover both singular and plural, unless otherwise indicated herein or clearly contradicted by context, and not as a definition of a term. Including, having, including, and containing are understood to be open-ended terms (meaning a phrase such as, including, but not limited to) unless otherwise noted. Connected, when unmodified and referring to physical connections, may be understood as partly or wholly contained within, attached to, or joined together, even if there is something intervening.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within range, unless otherwise indicated herein and each separate value is incorporated into specification as if it were individually recited herein. In at least one embodiment, use of a term, such as a set (for a set of items) or subset unless otherwise noted or contradicted by context, is understood to be nonempty collection including one or more members. Further, unless otherwise noted or contradicted by context, term subset of a corresponding set does not necessarily denote a proper subset of corresponding set, but subset and corresponding set may be equal.
Conjunctive language, such as phrases of form, at least one of A, B, and C, or at least one of A, B and C, unless specifically stated otherwise or otherwise clearly contradicted by context, is otherwise understood with context as used in general to present that an item, term, etc., may be either A or B or C, or any nonempty subset of set of A and B and C. In at least one embodiment of a set having three members, conjunctive phrases, such as at least one of A, B, and C and at least one of A, B and C refer to any of following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of A, at least one of B and at least one of C each to be present. In addition, unless otherwise noted or contradicted by context, terms such as plurality, indicates a state of being plural (such as, a plurality of items indicates multiple items). In at least one embodiment, a number of items in a plurality is at least two, but can be more when so indicated either explicitly or by context. Further, unless stated otherwise or otherwise clear from context, phrases such as based on means based at least in part on and not based solely on.
In at least one embodiment, even though the above discussion provides at least one embodiment having implementations of described techniques, other architectures may be used to implement described functionality, and are intended to be within scope of this disclosure. In addition, although specific responsibilities may be distributed to components and processes, they are defined above for purposes of discussion, and various functions and responsibilities might be distributed and divided in different ways, depending on circumstances.
In at least one embodiment, although subject matter has been described in language specific to structures and/or methods or processes, it is to be understood that subject matter claimed in appended claims is not limited to specific structures or methods described. Instead, specific structures or methods are disclosed as example forms of how a claim may be implemented.
From all the above, a person of ordinary skill would readily understand that the tool of the present disclosure provides numerous technical and commercial advantages, and can be used in a variety of applications. Various embodiments may be combined or modified based in part on the present disclosure, which is readily understood to support such combination and modifications to achieve the benefits described above.