Patent Publication Number: US-2023160273-A1

Title: Oil Field Tool Latch System and Method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO APPENDIX 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The disclosure generally relates to an apparatus and method for securing a tool in a tubular member. More specifically, the disclosure relates a latch system that can removably secure an oil field tool in a casing, wellhead, or other tubular member. 
     Description of the Related Art 
     The oil and gas industry ubiquitously installs tools into tubular members, such as casings, production tubing, and wellheads, to perform operations. Typically, the tools need longitudinal securing within the tubular members to withstand differential pressures between uphole and downhole portions of a wellbore. 
       FIG.  1    is a schematic cross sectional view of a typical wellhead with a casing hanger securing a casing inside a larger casing. A wellhead  2  is generally located above a wellbore and supports equipment downhole and at the surface. In this illustration, a large first casing  4  has been installed to a certain depth and is constrained upwardly by the wellhead  2 . A small second casing  6  is installed within the bore of the larger casing and suspended from the wellhead by a casing hanger  8 . A void area between an inner periphery of the large first casing  4  and the outer periphery of the small second casing  6  forms an annulus  18  that can be pressurized from downhole pressures that extend into the void area between the inner periphery of the wellhead and the outer periphery of the second casing. The casing hanger  8  is installed in an annulus  20  between the wellhead bore and the smaller casing in communication with the annulus  18 . A seal (not shown) can be installed above the casing hanger to seal off wellbore pressures in the annulus  18 . The casing hanger  8  is supported vertically by a shoulder  10  in the wellhead inner periphery and restrained from upward movement by a set of lockdown screws  12 . The lockdown screws  12  are spaced around an outside periphery of the wellhead and extend through holes  14  in the wellhead wall to extend into the bore of the wellhead. When tightened against the casing hanger  8 , a lockdown screw form a restraining surface  16  that engages the casing hanger and limits upward movement of the casing hanger. 
     While such a system is widely used in the oil field industry and other industries, a disadvantage can be the piercing of the wellhead wall, which functions as a pressure vessel to contain wellbore pressures often of 10,000 psi to 20,000 psi. For example, there may be eight or more lockdown screws and therefore eight or more holes that must be sealed through the wellhead wall against such pressures. Further, each lockdown screw needs to be installed to securely engage the casing hanger. Such an operation costs time and expense as a lost opportunity for other operations. 
     Therefore, there remains an improved latching method and system to secure a tool in a tubular member, such as a wellhead, casing, or other tubular member. 
     BRIEF SUMMARY OF THE INVENTION 
     The present disclosure provides a latch system that is activated internally after installation in a tubular member and requires no external penetration through a wall of the tubular member. The latch system and the tool on which it is installed includes an energizing ring and a lock ring resting on a portion of the tool, where the energizing ring can be pressed toward the lock ring to expand the lock ring radially outward and lock into an internal lock groove in a bore of the tubular member. A self-locking mechanism using corresponding profiles in the components can, with the lock ring expansion, longitudinally lock the energizing ring with the lock ring and lock the energizing ring with the tubular member. The dual locking of the three components locks or otherwise restrains the components together, so that the tool is fixed in a longitudinal position relative to the tubular member. 
     The internal latch system offers technical and operational advantages, including: minimizing leak paths through pressure vessels in which the latch system is installed; simplifying operation and installation of tools such as “bowl protector”, providing uniform and symmetrical contact on the lock ring against a tubular member, and requiring no external seal through a tubular member wall compared to a typical lockdown screw. 
     The disclosure provides an oil field tool configured to be secured inside a tubular member, comprising: a housing; and a latch system coupled with the housing, the latch system comprising: a lock ring coupled around a periphery of the housing and having a self-locking engagement profile on an inside periphery of the lock ring; and an energizing sleeve slidably coupled around the housing and longitudinally displaceable relative to the lock ring and having a self-locking engagement profile on an outside periphery of the energizing sleeve configured to engage with the lock ring self-locking engagement profile and restrain relative longitudinal movement between the lock ring and energizing sleeve. 
     The disclosure also provides a method of an oil field tool configured to be secured inside a tubular member, comprising: a housing; and a latch system coupled with the housing, the latch system comprising: a radially expandable lock ring coupled around a periphery of the housing and formed with slits through a longitudinal portion that is less than a longitudinal length of the ring; and an energizing sleeve slidably coupled around the housing and longitudinally displaceable relative to the lock ring. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG.  1    is a schematic cross sectional view of a typical wellhead with a casing hanger securing a casing inside a larger casing. 
         FIG.  2 A  is a schematic cross sectional view of an embodiment of a latch system according to the invention for a tool installed in a tubular member, such as a wellhead. 
         FIG.  2 B  is a schematic cross sectional view of an enlarged portion of the tool and latch system of  FIG.  2 A . 
         FIG.  3 A  is a schematic cross sectional view of the tool with the latch system energized. 
         FIG.  3 B  is a schematic cross sectional view of an enlarged portion of the tool and latch system of  FIG.  3 A . 
         FIG.  3 C  is a schematic cross sectional enlarged view of the latch system of  FIG.  3 A  illustrating at least one embodiment of self-locking engagement profiles. 
         FIG.  4 A  is a schematic top view of an embodiment of a lock ring of the latch system. 
         FIG.  4 B  is a schematic side view of the lock ring of  FIG.  4 A . 
         FIG.  4 C  is a schematic cross sectional view of the lock ring of  FIG.  4 A . 
         FIG.  4 D  is a schematic perspective view of the lock ring of  FIG.  4 A . 
         FIG.  5    is a schematic cross sectional view of an installation tool coupled with the tool having the latch system of  FIG.  3 A  prior to installation and activation. 
         FIG.  6    is a schematic cross sectional view of the installation tool coupled with the tool having the latch system of  FIG.  3 A  with the tool and latch system installed at location but prior to activation. 
         FIG.  7 A  is a schematic cross sectional view of the tool having the latch system of  FIG.  3 A  that is activated and latched with the tubular member and the casing hanger supported by the tubular member. 
         FIG.  7 B  is a schematic cross sectional view of an enlarged portion of  FIG.  7 A  with the tool having the latch system activated and latched with the tubular member. 
     
    
    
     DETAILED DESCRIPTION 
     The Figures described above and the written description of specific structures and functions below are not presented to limit the scope of what Applicant has invented or the scope of the appended claims. Rather, the Figures and written description are provided to teach any person skilled in the art how to make and use the inventions for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present disclosure will require numerous implementation-specific decisions to achieve the developer&#39;s ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related, and other constraints, which may vary by specific implementation, location, or with time. While a developer&#39;s efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of ordinary skill in this art having benefit of this disclosure. It must be understood that the inventions disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. The use of a singular term, such as, but not limited to, “a,” is not intended as limiting of the number of items. Further, the various methods and embodiments of the system can be included in combination with each other to produce variations of the disclosed methods and embodiments. Discussion of singular elements can include plural elements and vice-versa. References to at least one item may include one or more items. Also, various aspects of the embodiments could be used in conjunction with each other to accomplish the understood goals of the disclosure. Unless the context requires otherwise, the term “comprise” or variations such as “comprises” or “comprising,” should be understood to imply the inclusion of at least the stated element or step or group of elements or steps or equivalents thereof, and not the exclusion of a greater numerical quantity or any other element or step or group of elements or steps or equivalents thereof. The device or system may be used in a number of directions and orientations. The terms “top”, “up”, “upward”, “bottom”, “down”, “downwardly”, and like directional terms are used to indicate the direction relative to the figures and their illustrated orientation and are not absolute relative to a fixed datum such as the earth in commercial use. The term “inner,” “inward,” “internal” or like terms refers to a direction facing toward a center portion of an assembly or component, such as longitudinal centerline of the assembly or component, and the term “outer,” “outward,” “external” or like terms refers to a direction facing away from the center portion of an assembly or component. The term “coupled,” “coupling,” “coupler,” and like terms are used broadly herein and may include any method or device for securing, binding, bonding, fastening, attaching, joining, inserting therein, forming thereon or therein, communicating, or otherwise associating, for example, mechanically, magnetically, electrically, chemically, operably, directly or indirectly with intermediate elements, one or more pieces of members together and may further include without limitation integrally forming one functional member with another in a unitary fashion. The coupling may occur in any direction, including rotationally. The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and/or split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions. Some elements are nominated by a device name for simplicity and would be understood to include a system of related components that are known to those with ordinary skill in the art and may not be specifically described. Various examples are provided in the description and figures that perform various functions and are non-limiting in shape, size, description, but serve as illustrative structures that can be varied as would be known to one with ordinary skill in the art given the teachings contained herein. As such, the use of the term “exemplary” is the adjective form of the noun “example” and likewise refers to an illustrative structure, and not necessarily a preferred embodiment. Element numbers with suffix letters, such as “A”, “B”, and so forth, are to designate different elements within a group of like elements having a similar structure or function, and corresponding element numbers without the letters are to generally refer to one or more of the like elements. Any element numbers in the claims that correspond to elements disclosed in the application are illustrative and not exclusive, as several embodiments may be disclosed that use various element numbers for like elements. 
     The present disclosure provides a latch system that is activated internally after installation in a tubular member and requires no external penetration through a wall of the tubular member. The latch system and the tool on which it is installed includes an energizing ring and a lock ring resting on a portion of the tool, where the energizing ring can be pressed toward the lock ring to expand the lock ring radially outward and lock into an internal lock groove in a bore of the tubular member. A self-locking mechanism using corresponding profiles in the components can, with the lock ring expansion, longitudinally lock the energizing ring with the lock ring and lock the energizing ring with the tubular member. The dual locking of the three components locks or otherwise restrains the components together, so that the tool is fixed in a longitudinal position relative to the tubular member. 
       FIG.  2 A  is a schematic cross sectional view of an embodiment of a latch system according to the invention for a tool installed in a tubular member, such as a wellhead.  FIG.  2 B  is a schematic cross sectional view of an enlarged portion of the tool and latch system of  FIG.  2 A . A tubular member  22 , such as a wellhead, has a bore forming an inner periphery  24  with a longitudinal axis  26 . A casing  6  such as described in  FIG.  1    can form an annulus  20  between the outer periphery of the casing and the inner periphery  24  of the tubular member  22 . In this embodiment, a casing hanger  32  can be set in the tubular member and supported on a shoulder  10  described above. A tool  28 , such as without limitation a pack-off and seal assembly, has at least one embodiment of a latch system  30 , shown in this figure in a deactivated state. A housing  34  of the tool  28  can house various components, allow test pressure communication, and provide flow-by ports for drilling fluids and wellhead annulus pressure buildup. The tool  28  can be configured with thread profiles to engage a running tool and other delivery mechanisms to place the tool  28  in an appropriate location in a wellbore, allow disengagement of the running tool after placement, and possible later retrieval of the tool. The tool  28  can engage the casing hanger  32  and seal the annulus  20  with the latch system engaged between the tubular member inner periphery  24  and an outer periphery of the tool  28 . Once latched, the tool  28  can restrain longitudinal movement of the casing hanger, which is generally an upward movement restraint in the orientation shown in the figures. Outer seals  50  on tool  28  can seal against the tubular member inner periphery  24 , and inner seals  52  on tool  28  can seal against another tool, such as the casing hanger  26 . The seals can be elastomeric seals and can rely on an interference between the opposing sealing surfaces to cause a pressure tight seal under. The seals  50  and  52  can prevent pressure migration from one annulus area to another to control and maintain well integrity. 
     More specifically, in at least this embodiment, the tool  28  can have a housing  34  with an outer periphery  36 . A shoulder  38  can be formed on the outer periphery  36  to support the latch system  30 . The latch system  30  includes a lock ring  40  and an energizing sleeve  42 . The inner periphery  24  of the tubular member  22  has a lock groove  44  to receive the lock ring when activated. In a deactivated state, the lock ring  40  can be supported by the shoulder  38 . The energizing sleeve  42  can be longitudinally displaced along the longitudinal axis  26  from the lock ring  40 . The displacement allows the lock ring  40  to compress inwardly toward the outer periphery  36  of the tool housing  34  to a minimum diameter allowed by the energizing sleeve  40 . To facilitate relative movement between the surfaces of the lock ring  40  and the energizing sleeve  42 , one or both of the surfaces may have a taper or other shapes to bias the components in a desired direction during activation. 
     Other tooling  34 ,  36 , and  38  can be coupled uphole from the tool  28 , not pertinent to the present disclosure.  FIGS.  2 A and  2 B  show an example of an embodiment in which a tool can use the latch assembly described herein. Other tools, other locations, and other purposes can use the latch system in the oil field installations and the embodiment is not limiting. 
       FIG.  3 A  is a schematic cross sectional view of the tool with the latch system energized.  FIG.  3 B  is a schematic cross sectional view of an enlarged portion of the tool and latch system of  FIG.  3 A .  FIG.  3 C  is a schematic cross sectional enlarged view of the latch system of  FIG.  3 A  illustrating at least one embodiment of self-locking engagement profiles. The tool housing  34  is shown with the energizing sleeve  42  longitudinally aligned with the lock ring  40  on the shoulder  38  compared to being longitudinally displaced from the lock ring and shoulder in  FIGS.  2 A and  2 B . In this longitudinally aligned position, the energizing sleeve  42  exerts a radial force outwardly (away from the longitudinal axis  26 ) on the lock ring  40  that forces the lock ring toward the tubular member lock groove  44  to engage the lock groove, described above. A tapered surface  46  on the lock ring  40  can engage with a tapered surface  48  on the energizing sleeve  42  to facilitate moving the lock ring radially outwardly in opposition to the radial bias inwardly of the lock ring. 
     The latch system  30  features a self-locking mechanism  54  that is independent of typical lockdown screws such as shown in  FIG.  1   , requires no external actuation as the lockdown screws, and thus can avoids holes through the wall of the tubular member. The self-locking mechanism  54  can be actuated by the longitudinal movement of the energizing ring to activate the lock ring outwardly as described. In at least one embodiment, the self-locking mechanism  54  includes an outer self-locking engagement profile  58  on an outside periphery of the energizing sleeve  42  configured to engage with an inner self-locking engagement profile  56  on an inner periphery of the lock ring  40  and restrain relative longitudinal movement between the lock ring and energizing sleeve. In at least one embodiment, one of the self-locking engagement profiles can be a protrusion and another of the self-locking engagement profiles can be a groove that fits the protrusion. 
     The self-locking mechanism  54  can further have self-locking profiles between the energizing sleeve  42  and the tool housing  34 . Therefore, the self-locking mechanism  54  can be considered a dual self-locking mechanism. The energizing sleeve  54  can have an inner self-locking engagement profile  60  and the tool housing  34  can have an outer self-locking engagement profile  62 . In this embodiment, a compressible member  64  can be placed between the inner self-locking engagement profile  60  and the outer self-locking engagement profile  62  for longitudinally coupling the profiles. The amount of compressibility and therefore the resistance to decoupling (and coupling) can be varied by the stiffness of the member measured by its durometer. The durometer of the compressible member can be relatively high to provide a high degree of stiffness for coupling the energizing sleeve  42  with the tool housing  34 . In practice, the compressible member  64  can be placed circumferentially around the outer self-locking engagement profile  62  of the tool housing  34  and so be present as the energizing sleeve  42  moves longitudinally along the tool housing to activate the lock ring  40 . The energizing sleeve  42  can slide over the compressible member  64  to compress the member  64  radially into the tool housing outer self-locking engagement profile  62  until the energizing sleeve inner self-locking engagement profile  60  aligns with the tool housing outer self-locking engagement profile  62  and compression member  64  is at least partially released to fit into the inner self-locking engagement profile  60 . When the compression member  64  is engaged in the inner self-locking engagement profile  60  and the tool housing outer self-locking engagement profile  62 , the energizing sleeve  42  is restrained longitudinally with the tool housing  34 . 
     Thus, the combination of the two sets of self-locking engagement profiles and compression member result in (1) a first portion of the self-locking mechanism  54  restraining the lock ring  40  with the energizing sleeve  42 , and (2) a second portion of the self-locking mechanism  54  restraining the energizing sleeve  42  with the tool housing. The restraining of both sets of self-locking engagement profiles occurs in conjunction with the activation of the lock ring  40  into the tubular member lock groove  44 . When the first portion of the self-locking mechanism is activated, then the lock ring  40  is activated into the tubular member lock groove  44 , as described above. Thus, the tubular member  22  is restrained longitudinally with the tool housing  34 . The restraint occurs independent of external lockdown screws and the external actions, other than those actions causing the energizing sleeve  42  to move longitudinally along the tool housing, such as with a running tool known in the art. 
     The lock ring  40  can also have a hook profile  66  facing radially outwardly from the tool housing  34 . A running tool (not shown) can be configured to engage the hook profile  66  and pull the energizing sleeve  42  back into a longitudinally displaced position relative to the lock ring. Displacing the energizing sleeve longitudinally from the lock ring allows the lock ring  40  to return radially inward to a disengaged position from the tubular member  22 . Displacing the energizing sleeve longitudinally also decouples the energizing sleeve  42  from the tool housing  34 . The tool  28  can be retrieved from the installation location. For example, this decoupling may be necessary when the seals are damaged during installation and will not hold pressure during a pressure test. 
       FIG.  4 A  is a schematic top view of an embodiment of a lock ring of the latch system.  FIG.  4 B  is a schematic side view of the lock ring of  FIG.  4 A .  FIG.  4 C  is a schematic cross sectional view of the lock ring of  FIG.  4 A .  FIG.  4 D  is a schematic perspective view of the lock ring of  FIG.  4 A . In at least one embodiment, the lock ring  40  can be a C-type configured ring having a split  70  entirely across the longitudinal cross-section to allow expansion and contraction of an effective diameter of the lock ring. The lock ring  40  can include the tapered surface  48  described above that can be engaged with the energizing sleeve tapered surface  46 . Further, the lock ring  40  can include a first outer tapered surface  72  and a second outer tapered surface  74  on an outside periphery to facilitate engagement into the tubular member lock groove  44 . The lock ring inner self-locking engagement profile  56 , described above, is shown enlarged in  FIG.  4 C . In at least one embodiment, the profile  56  can be in the form of a groove to receive a corresponding protruding profile from the energizing ring  42 . An inner projection  76  can be formed in the lock ring  40  to further restrict longitudinal movement relative to the energizing ring  42  when assembled on the tool housing  34  (shown above). 
     The strength of the lock ring  40  in resisting longitudinal movement of the tool  28  relative to the tubular member  22  is in the lock ring shear resistance in a longitudinal direction of its cross-section from the engagement of the lock ring into the tubular member lock groove  44 . Thus, the radial expansion can advantageously be flexible, so that the lock ring  40  can be radially activated with a minimal amount of activation force from the energizing sleeve  42  when the lock ring is expanded to the locking position described above. To facilitate reducing a required activation force, the lock ring  40  can be partially split longitudinally across portions of its longitudinal length while leaving a portion that is not split. For example, a first split  80  can be formed in an upper portion of the lock ring  40  for a length LS1 and leave a remaining material  84  having a length LM1 that is not split, so that the total length of LS1+LM1=L can be the length of the longitudinal cross-section of the lock ring. To allow a more uniform peripheral radial movement of the lock ring  40 , a similar opposing second split  82 , which is circumferentially offset from the first split, can be formed in a lower portion of the lock ring  44  for a length LS2 and leave a remaining material LM2 that is not split, so that the total length of LS2+LM2=L. The opposing splits can be alternated around the circumference of the lock ring  40 . The alternating sequence around the circumference assists in the lock ring expanding with less activation force in a more uniform manner that can maintain a longitudinal orientation of the lock ring cross section that is similar whether compressed or expanded. 
       FIG.  5    is a schematic cross sectional view of an installation tool coupled with the tool having the latch system of  FIG.  3 A  prior to installation and activation. The latch system  30  is shown in a retracted decoupled state on the tool  28 . The tool  28  is ready for installation at a pre-determined location. In an example, a landing assembly of tubing  90  (such as casing) can be used to deliver the tool to the location. The landing assembly  90  can be coupled to a running tool  92  to assist in temporarily holding the tool  28  during delivery. An adapter  94  can be used to transition between the running tool  92  and the tool  28  and rotatably coupled with the running tool. In at least one embodiment, the landing assembly, running tool, adapter if used, and the tool  28  can be threaded together for delivery, and then reverse rotated to release the tool  28  at the location. If left-hand threads are used, the running tool with the adapter can be rotated counter-clockwise along a running thread on the tool  28  to engage the tool, while not so far as to press the energizing sleeve  42  longitudinally into the lock  40  to actuate the lock ring. 
       FIG.  6    is a schematic cross sectional view of the installation tool coupled with the tool having the latch system of  FIG.  3 A  with the tool and latch system installed at location but prior to activation.  FIG.  7 A  is a schematic cross sectional view of the tool having the latch system of  FIG.  3 A  that is activated and latched with the tubular member and the casing hanger supported by the tubular member.  FIG.  7 B  is a schematic cross sectional view of an enlarged portion of  FIG.  7 A  with the tool having the latch system activated and latched with the tubular member. The assembly shown in  FIG.  5    can be inserted into the tubular member  22  and delivered to the intended location. On delivery to the location, the assembly can be pressure tested. The running tool  92  with the adapter  94  can be rotated several turns along the running tool thread  96  to further engage the tool  28  and press the energizing sleeve  42  longitudinally into the lock ring  40 , such as by engaging the tapered surfaces shown in  FIGS.  3 B and  3 C . The engagement by the energizing sleeve  42  expands the lock ring  40  radially outward into the tubular member lock groove  44 . Concurrently, the energizing sleeve  42  is longitudinally pressed into position between the lock ring  40  and the housing  34  of the tool  28  to engage the self-locking mechanism  54  described above between the energizing sleeve and the lock ring and between the energizing sleeve and the housing. With the lock ring engaged with the tubular member and the self-locking mechanism engaged between the three components, the tool  28  is positively restrained in position at the location. The running tool can be rotated in a reverse direction and removed from the bore of the tubular member, as shown in  FIG.  7 A . 
     The tool  28  can be released from the tubular member  22  by reengaging a running tool to the tool and latch assembly. The running tool can include an internal mating hook profile corresponding to the external hook profile  66  of the energizing ring  42 . The running tool can engage with the hook profile  66  and pull the energizing ring  42  longitudinally away from the lock ring  40  with sufficient force to disengage the self-locking mechanism  54 . With sufficient longitudinal movement of the energizing ring, the lock ring can be allowed to return radially inward to disengage with the tubular member lock groove  44 . Once disengaged from the tubular member lock groove  44 , the running tool can move the tool  28  to a different location, such as uphole to the surface. 
     The latch system  30  has been described for use with a tool, such as a pack-off and seal assembly, with the understanding that the latch system can be used with a number of tools of various description and purposes, and so is not limited to the examples described herein. Further, sensors, gauges, and measuring instruments have not been described but are typically used in such tools. 
     Other and further embodiments utilizing one or more aspects of the inventions described above can be devised without departing from the disclosed invention as defined in the claims. For example, some of the components could be arranged in different locations in the housing, and other variations that are limited only by the scope of the claims. 
     The invention has been described in the context of preferred and other embodiments, and not every embodiment of the invention has been described. Obvious modifications and alterations to the described embodiments are available to those of ordinary skill in the art. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by the Applicant, but rather, in conformity with the patent laws, Applicant intends to protect fully all such modifications and improvements that come within the scope of the following claims.