Patent Publication Number: US-8967279-B2

Title: Reinforced shear components and methods of using same

Description:
BACKGROUND 
     1. Field of Invention 
     The invention is directed to releasable members that retain one element in a position relative to another element until such time as an outside stimulus causes the releasable member to actuate and allow movement of at least one of the elements to move relative to the other element and, and in particular, to a shear component that retains the two elements in a first position until being broken and allowing at least one of the elements to move relative to the other element. 
     2. Description of Art 
     Shear components such as shear pins and shear screws are known in the art. In general, a shear component is used to retain one element to another element until a predetermined event occurs causing the shear component to release the connection between the two elements. In one specific example, a shear component such as shear pin or shear screw is inserted through the wall of a first element, such as a slidable sleeve, and into the wall of a second element, such as a mandrel, to retain the slidable sleeve in a first or fixed position. Upon application of a stimulus, such as an increase in pressure across the shear component, the shear component is compromised by being broken into two or more pieces allowing the first element to move relative to the second element. Applications of shear components include downhole tools used in oil and gas exploration and production environments where the tool is disposed within the well and pressure is applied to the shear component. At a predetermined pressure level, the shear component breaks allowing movement of one element of the tool, such as a slidable sleeve to actuate the downhole tool. 
     SUMMARY OF INVENTION 
     Broadly, shear components for releasably securing a first component to a second component comprise a body having a first end, a second end, an outer wall surface, an inner wall surface defining a cavity, a shear plane, and a core disposed within the cavity and in sliding engagement with the inner wall surface of the body. The core shifts between a first position in which the core is disposed in alignment with the shear plane, and a second position in which the core is disposed out of alignment with the shear plane. When in the first position, the core provides added strength to the shear component to mitigate the risk of prematurely shearing the component. When in the second position, the amount of force required to compromise or fail the shear component is reduced. Accordingly, the now vacant cavity across the shear plane has a shear strength less than a traditional element. As a result, the shear component provides selective strengthening depending on the location of the core within the cavity. 
     The shear component can be included in a downhole tool to maintain the downhole tool in the run-in or initial position until being compromised by a stimulus. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view of a specific embodiment of a shear component disclosed herein shown in a first position. 
         FIG. 2  is a cross-sectional view of the shear component shown in  FIG. 1  shown in a second position. 
         FIG. 3  is a cross-sectional view of another specific embodiment of a shear component disclosed herein shown in a first position. 
         FIG. 4  is a cross-sectional view of the shear component shown in  FIG. 3  shown in a second position. 
         FIG. 5  is a cross-sectional view of an additional specific embodiment of a shear component disclosed herein shown in a first position. 
         FIG. 6  is a cross-sectional view of the shear component shown in  FIG. 5  shown in a second position. 
         FIG. 7  is a cross-sectional view of a downhole tool disposed in wellbore showing shear components of the embodiments of  FIGS. 1-6  retaining the downhole tool in its run-in position. 
         FIG. 8  is a cross-sectional view the downhole tool of  FIG. 7  showing the shear components of the embodiments of  FIGS. 1-6  having been compromised so that the downhole tool has moved to its set position. 
     
    
    
     While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF INVENTION 
     Referring now to  FIGS. 1-2 , in one specific embodiment, shear component  20  comprises body  22  having first end  21 , second end  23 , outer wall surface  24 , and cavity  25  defined by inner wall surface  26 . Outer wall surface  24  includes groove  29  disposed along shear plane  28 . Shear plane  28  is the plane passing through body  22  which is the weakest point along body  22  and along which body  22  is compromised or broken. 
     In the embodiment of  FIGS. 1-2 , first end  21  is closed and second end  23  includes opening  27  that is in fluid communication with cavity  25 . It is to be understood, however, that first end  21  is not required to be closed. Disposed within cavity  25  in sliding engagement with inner wall surface  26  is core  30 . Core  30  includes first end  31 , second end  32 , first portion  33  having outer diameter  34 , and second portion  35  having outer diameter  36 . Outer diameter  34  is in sliding engagement with inner wall surface  26 . Outer diameter  36  is smaller than outer diameter  34  and is not in sliding engagement with inner wall surface  26 . Although core  30  is shown as having two portions,  33 ,  35  with portion  33  having an outer diameter  34  that is greater than the outer diameter  36  of portion  35 , core  30  is not required to have this configuration. Instead, core  30  can have a single portion of which the entire outer diameter is in sliding engagement with inner wall surface  26  of body  22 . 
     Core  30  has a first position ( FIG. 1 ) and a second position ( FIG. 2 ). In the first position, core  30  is disposed within cavity  25  across, or in alignment with, shear plane  28  and held between actuator  40  and corrodible member  42  with corrodible member  42  being held in place by retaining ring  44 . Thus, in the first position, the shear strength of body  22  is higher across shear plane  28  as compared to when core  30  is moved out of alignment of shear plane  28 , thereby reducing the possibility of unintentionally shearing. Core  30  can be formed out of any material desired or necessary to provide strength to shear component  20  such that reduces the likelihood of unintentional shearing. Suitable materials include alloy steels. 
     In the embodiment of  FIGS. 1-2 , actuator  40  comprises a compressive member shown as a spring. However, the compressive member is not required to be a coiled spring, but instead can be an elastomeric material, Belleville washers, or any other material or device that can be compressed to store energy that can later be released to facilitate movement or actuation of core  30  from the first position to the second position. 
     As used herein “corrodible member” means that the member is capable of being corroded, dissolved, degraded, disintegrated or otherwise compromised by a stimulus such that it can no longer provide the function for which it was designed. Thus, corrodible member  42  is initially designed to maintain core  30  in the first position ( FIG. 1 ) and, as it is corroded or otherwise has its integrity compromised, it can no longer maintain core  30  in the first position. Suitable corrodible materials for forming corrodible member  42  include, but are not limited to electrolytic materials such as those disclosed and described in U.S. Patent Publication No. 2011/0132620 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0132619 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0132621 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0136707 filed in the name of Xu, et al., U.S. Patent Publication No. 2011/0132612 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0135953 filed in the name of Xu, et al., U.S. Patent Publication No. 2011/0135530 filed in the name of Xu, et al., and U.S. Patent Publication No. 2012/0024109 filed in the name of Xu, et al., each of which is hereby incorporated by reference in its entirety. 
     In addition, corrodible member  42  is not required to be formed completely out of a corrodible material. To the contrary, portions of corrodible member  42  can be formed out of non-corrodible materials. For example, corrodible member  42  may include pieces of non-corrodible material that are held together by one or more corrodible materials. In these examples, the corrodible material portions are corroded or otherwise become compromised causing the entire corrodible member  42  to break apart. Thus, while not all of the corrodible member  42  is “corroded,” it is sufficiently compromised to permit core  30  to move from its first position ( FIG. 1 ) to its second position ( FIG. 2 ). 
     When core  30  is in the first position ( FIG. 1 ), actuator  40  is in its initial position. In embodiments such as the one illustrated in  FIGS. 1-2 , when actuator  40  is a compressible member, the compressible member is in its compressed position when core  30  is in the first position such that the compressible member is biased toward second end  23 . In other words, the compressive member contains stored energy that is trying to push core  30  toward second end  23  but is unable to do so due to corrodible member  42  and retaining ring  44 . 
     In operation of the embodiment of  FIGS. 1-2 , and with further reference to  FIGS. 7-8 , downhole tool  100  ( FIGS. 7-8 ) is shown disposed within wellbore  106  to define wellbore annulus  108 . Downhole tool  100  is illustrated as a ball seat having first and second components  102 ,  104  initially held in place relative to one another by shear component  20 ,  50 ,  70 . Shear components  50  and  70  are discussed in greater detail below with respect to  FIGS. 3-6 . Shear component  20 ,  50 ,  70  is disposed through first component  102  and second component  104  ( FIG. 7 ) such that first ends  21 ,  51 ,  71 , and second ends  23 ,  53 ,  72  are exposed to bore  101  of downhole tool  100  and wellbore annulus  108 , respectively. However, it is to be understood, that in the embodiment of  FIGS. 1-2 , first end  21  can be exposed to either bore  101  or wellbore annulus  108 . 
     After assembly, downhole tool  100  is run-in to wellbore  106  to the desired location on a work or tool string (not shown). A stimulus such as a corrosive fluid either already disposed in the wellbore, or pumped down the wellbore, or pumped down bore  101 , acts on corrodible member  42  causing it to be compromised such as through dissolution, degradation, or other known mechanism due to the corrosive fluid passing through opening  27 . Upon corrodible member  42  being compromised, the actuator is actuated from its initial position to its actuated position. As illustrated in the embodiment of  FIGS. 1-2 , the stored energy within the compressive member is released causing the compressive member to move from a compressed or stored energy position ( FIG. 1 ) to an expanded or released energy position (such as shown in  FIG. 2 ). As a result, core  30  is pushed toward second end  23  until it is no longer disposed across, or in alignment with, shear plane  28 . By moving core  30  out of alignment with shear plane  28 , body  22  of shear component  20  is weakened so that body  22  is more readily compromised or broken due to a stimulus such as gravity, mechanical force, or fluid pressure acting on shear component  20 . With reference to  FIGS. 7-8 , shear component  20  is compromised by fluid pressure building above ball  110  forcing ball  110  into first component  102  which, in turn, exerts force across shear plane  28  of shear component  20 . After shear component  20  is compromised or otherwise fails, first component  102  is permitted to move relative to second component  104  such as shown in  FIG. 8  so that a downhole operation is performed by the downhole tool. In the case of downhole tool  100 , ports  105  are opened such that bore  101  is placed in fluid communication with wellbore annulus  108 . 
     With reference to  FIGS. 3-4 , in another embodiment, shear component  50  comprises body  52  having first end  51  having opening  66 , second end  53  having opening  54 , outer wall surface  55 , and cavity  56  defined by inner wall surface  57 . Opening  54  can be a hex-hole to facilitate installation of shear component  50  into a downhole tool. Outer wall surface  55  includes groove  59  disposed along shear plane  58 . Shear plane  58  is the plane passing through body  52  which is the weakest point along body  52  and along which body  52  is compromised or broken. 
     Openings  54 ,  66  are in fluid communication with opposite ends of cavity  56 . As shown in  FIGS. 3-4 , opening  66  is larger than opening  54 . Disposed within cavity  56  in sliding engagement with inner wall surface  57  is core  60 . Core  60  includes first end  61 , second end  62 , and seal ring  63  disposed along outer diameter  64  of core  60 . Seal ring  63  can be any elastomeric ring such as an O-ring to reduce leakage of fluid between the interface of core  60  with inner wall surface  57  of body  52 . 
     Core  60  has a first position ( FIG. 3 ) and a second position ( FIG. 4 ). In the first position, core  60  is disposed within cavity  56  across, or in alignment with, shear plane  58  and held between compressive member  68  and retaining ring  69 . Thus, in the first position, the shear strength of body  52  is higher across shear plane  58  as compared to when core  60  is moved out of alignment of shear plane  58 , thereby reducing the possibility of unintentionally shearing. Core  60  can be formed out of any material desired or necessary to provide strength to shear component  50  such that reduces the likelihood of unintentional shearing. Suitable materials include the materials listed above with respect to core  30 . 
     In the embodiment of  FIGS. 3-4 , compressive member  68  comprises a coiled spring. However, compressive member  68  is not required to be a spring, but instead can be an elastomeric material, Belleville washers, or any other material or device that can be compressed to store energy that can later be released. 
     When core  60  is in the first position ( FIG. 3 ), compressive member  68  is in its expanded or released energy position. In other words, compressive member  68  is pushing core  60  toward first end  51  and, thus, into retaining ring  64 . Accordingly, compressive member  68  facilitates retaining core  60  in the first position. 
     In operation of the embodiment of  FIGS. 3-4 , and with further reference to  FIGS. 7-8 , downhole tool  100  ( FIGS. 7-8 ) is shown disposed within wellbore  106  to define wellbore annulus  108 . Shear component  50  is disposed through first component  102  and second component  104  ( FIG. 7 ) such that first end  51  and second end  53  are exposed to bore  101  of downhole tool  100  and wellbore annulus  108 , respectively. 
     After assembly, downhole tool  100  is run-in to wellbore  106  to the desired location on a work or tool string (not shown). A stimulus such as fluid pressure is pumped down bore  101  of downhole tool  100 . The fluid pressure passes through opening  66  and enters cavity  56 . The fluid pressure then exerts force on first end  61  of core  60  causing core  60  to slide along inner wall surface  57  of body  52  toward second end  53 . In so doing, compression member  68  is moved from an expanded position ( FIG. 3 ) to a compressed position ( FIG. 4 ) and core  60  is moved from its first position ( FIG. 3 ) to its second position ( FIG. 4 ). As a result, core  60  is no longer disposed across, or in alignment with, shear plane  58 . By moving core  60  out of alignment with shear plane  58 , body  52  of shear component  50  is weakened so that body  52  is more readily compromised or broken due to a stimulus such as gravity, mechanical force, or fluid pressure acting on shear component  50 . With reference to  FIGS. 7-8 , shear component  50  is compromised by fluid pressure building above ball  110  forcing ball  110  into first component  102  which, in turn, exerts force across shear plane  58  of shear component  50 . After shear component  50  is compromised or otherwise fails, first component  102  is permitted to move relative to second component  104  such as shown in  FIG. 8  so that a downhole operation is performed by the downhole tool. In the case of downhole tool  100 , ports  105  are opened such that bore  101  is placed in fluid communication with wellbore annulus  108 . 
     Referring now to  FIGS. 5-6 , in another embodiment, shear component  70  comprises body  72  having first end  71  having opening  86 , second end  73  having opening  74 , outer wall surface  75 , and cavity  76  defined by inner wall surface  77 . Opening  74  can be a hex-hole to facilitate installation of shear component  50  into a downhole tool. Outer wall surface  75  includes groove  79  disposed along shear plane  78 . Shear plane  78  is the plane passing through body  72  which is the weakest point along body  72  and along which body  72  is compromised or broken. 
     Openings  74 ,  86  are in fluid communication with opposite ends of cavity  76 . As shown in  FIGS. 5-6 , opening  86  is larger than opening  74 . Disposed within cavity  76  in sliding engagement with inner wall surface  77  is core  80 . Core  80  includes first end  81 , second end  82 , and seal ring  83  disposed along outer diameter  84  of core  80 . Seal ring  83  can be any elastomeric ring such as an O-ring to reduce leakage of fluid between the interface of core  80  with inner wall surface  77  of body  72 . 
     Core  80  has a first position ( FIG. 5 ) and a second position ( FIG. 6 ). In the first position, core  80  is disposed within cavity  76  across, or in alignment with, shear plane  78 . Core  80  is held in the first position by retaining ring  87  and shear ring  88 . Thus, in the first position, the shear strength of body  72  is higher across shear plane  78  as compared to when core  80  is moved out of alignment of shear plane  78 , thereby reducing the possibility of unintentionally shearing. Core  80  can be formed out of any material desired or necessary to provide strength to shear component  70  such that reduces the likelihood of unintentional shearing. Suitable materials include the materials listed above with respect to core  30 . 
     In operation of the embodiment of  FIGS. 5-6 , and with further reference to  FIGS. 7-8 , downhole tool  100  ( FIGS. 7-8 ) is shown disposed within wellbore  106  to define wellbore annulus  108 . Shear component  70  is disposed through first component  102  and second component  104  ( FIG. 7 ) such that first end  71  and second end  73  are exposed to bore  101  of downhole tool  100  and wellbore annulus  108 , respectively. 
     After assembly, downhole tool  100  is run into wellbore  106  to the desired location on a work or tool string (not shown). A stimulus such as fluid pressure is pumped down bore  101  of downhole tool  100 . The fluid pressure passes through opening  86  and enters cavity  76 . The fluid pressure then exerts force on first end  81  of core  80  causing shear ring  88  to be compromised or broken so that core  80  can slide along inner wall surface  77  of body  72  toward second end  73 . In so doing, core  80  is moved from its first position ( FIG. 5 ) to its second position ( FIG. 6 ). As a result, core  80  is no longer disposed across, or in alignment with, shear plane  78 . By moving core  80  out of alignment with shear plane  78 , body  72  of shear component  70  is weakened so that body  72  is more readily compromised or broken due to a stimulus such as gravity, mechanical force, or fluid pressure acting downward on shear component  70 . With reference to  FIGS. 7-8 , shear component  70  is compromised by fluid pressure building above ball  110  forcing ball  110  into first component  102  which, in turn, exerts force across shear plane  78  of shear component  70 . After shear component  70  is compromised or is otherwise failed, first component  102  is permitted to move relative to second component  104  such as shown in  FIG. 8  so that a downhole operation is performed by the downhole tool. In the case of downhole tool  100 , ports  105  are opened such that bore  101  is placed in fluid communication with wellbore annulus  108 . 
     It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, the corrodible member is not required to be held in place initially by a retaining ring. Instead, corrodible member itself may be affixed to the body to maintain the core in its first position until the corrodible member is sufficiently compromised or degraded such that the compressive member can overcome the corrodible member to push the core toward the second end. Further, the corrodible member is not required to be a ring having an opening in its middle. Instead, it can be a plate or other suitable shaped member. In addition, the groove in outer wall surface of the body of shear component is not required. Moreover, the term “shear plane” can be indistinguishable from any other plane along the length of the shear component. Thus, the term “shear plane” refers to the plane or planes along the length of the shear component that are compromised such that the shear component releases from its connection. Additionally, the openings in the first ends of the embodiments shown in  FIGS. 3-6  are not required to be larger than the openings in the second ends of these embodiments. Instead, the openings in the first ends can be smaller than, or equal in size, to the openings in the second ends. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.