Patent Publication Number: US-11021928-B2

Title: Setting adapter assembly for plug

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This present application claims priority under 35 U.S.C. Sections 119(e) from U.S. Provisional Patent Application Ser. No. 62/746,346, filed on Oct. 16, 2018, entitled “Setting Adapter Assembly for Plug”. 
    
    
     FIELD 
     The disclosure relates generally to subsurface well apparatus. The disclosure relates specifically to apparatus for setting packers, such as plugs. 
     BACKGROUND 
     In the drilling, completing of oil wells, it is often necessary to isolate particular zones within the wall. In some applications, downhole tools, known as bridge plugs, fracture (‘frac’) plugs, and the like, are inserted into the well to isolate zones. The purpose of the bridge plug or frac plug is to isolate some portion of the well from another portion of the well. For example, perforation in the well in one portion may need to be isolated from perforations in another portion of the well, or there may be a need to isolate the bottom of the well from the wellhead. Accordingly, the plug may experience a high differential pressure, and must be capable of withstanding the pressure so that the plug seals the well, and does not move in the well after being set. 
     A plug is generally comprised of one or two slips and cones as well as an elastomeric packing element arranged about a mandrel that is run into the wellbore. The slip may be initially formed in a ring, designed to break apart upon the application of an axial force. The slip includes a tapered surface that is adapted to mate with a tapered surface of the cone. As an axial force is applied to the plug, relative movement between the slip and the cone happens, the slip moves up on the tapered surface of the cone and breaks apart to form a number of individual slip elements, and the slip elements are driven outwardly, away from the mandrel, and thus engages the casing wall, locking the slip in place within the casing. Further application of axial force compresses the elastomeric packing element, driving the packing element outwardly to contact and seal against the wellbore. The axial compression of the packing element causes the packing element to expand radially against the well casing creating a sealing barrier that isolate a portion of the well. 
     When it is desired to remove one or more of these plugs from a wellbore, it is often simpler and less expensive to mill or drill them out rather than to implement a complex retrieving operation. In milling, a milling cutter is used to grind the plug. In drilling, a drilling bit is used to cut and grind up the components of the plug to remove it from the wellbore. the milling or drilling operations may be slowed because of the materials of the packer or bridge plug employed. For example, these downhole tools are frequently formed including metallic components, such as hardened iron or steel, which are difficult, or require specialized tools and techniques, to mill or drill. 
     The process and apparatus required for setting a plug in a well have been more complicated, expensive and time consuming than is desirable. Setting of a plug is normally performed by slickline, braided line, wireline or coiled tubing. Setting devices usually need for a bottom cap and shear pins to help applying pressure on the plug such that the plug can be locked in the well. Furthermore, one difficulty associated with setting a plug is that the setting device is de-coupled form the plug after the plug has been completely and successfully deployed. The setting device usually provide shear pins to connect the plug, after setting the plug, pulling the setting device outward to shear the pin to disconnect the plug, in this case, the plug will endure tensile forces to keep locking on the wall of the well. In order to endure the tensile forces and to avoid the rupture of the plug when the setting device is de-coupling form the plug, the wall of the plug body need a certain thickness to have sufficient strength. Therefore, the inner diameter of the plug will decrease, the milling or drilling operations may be slowed because of the thick wall of the plug. 
     Therefore, it would be advantageous to provide improved setting device of novel construction which is simple, and capable of rapid and efficient operation. 
     SUMMARY 
     The present invention is directed to a method and system for setting a plug at a desired location in the wellbore. The novel construction of the system leads the setting of plug simple, inexpensive and dependable and capable of rapid and efficient operation. 
     In one aspect, the invention is directed to a setting adapter assembly for setting a plug, comprises a setting body, a crossover sub, a shear ring connecting the setting body and the crossover sub temporarily, a rotating dog carrier at a lower end of the setting body, a plurality of rotating dogs accommodated in the rotating dog carrier; an inner mandrel fixedly connecting with the crossover sub and extends through the shear ring, the setting body and coming into an inner chamber of the rotating dog carrier. wherein the rotating dogs are arranged at the bottom of the plug and in their vertical position to compress the plug during a process of setting the plug, and during a process of withdrawing the setting adapter assembly, the rotating dogs rotate 90 degrees into their horizontal position driven by the movement of the inner mandrel to allow the setting adapter assembly pass through the plug. 
     In one embodiment, the rotating dog carrier comprises a plurality of dog carrier subs to accommodate corresponding rotating dogs. Each of the rotating dogs comprising a setting tab and a pivot pin. The dog carrier subs comprising slots to accommodate the pivot pins. 
     In some embodiments pertain to the inner mandrel, the inner mandrel comprises a pocket to accommodate a portion of the setting tabs when the rotating dogs are in their vertical position. setting tab comprising a ramped face, the inner mandrel comprising a bottom end being adjacent the pocket, the bottom end comprising a ramped leading edge face for engaging ramped face of the setting tab. 
     In some embodiments, the setting adapter assembly further comprising a travel restriction mechanism to limit the distance that the inner mandrel can move in the setting body. the travel restriction mechanism comprising a locking ring and a circumferential groove. The locking ring is embedded in a slot in the inner surface of the setting body and is located adjacent a bottom end of the shear ring. The length of the circumferential groove is configured to allow the inner mandrel to move from initial position to the position that the bottom end abuts the setting tab to keep the rotating dogs in their horizontal position. 
     In another aspect, the invention is directed to a method for setting a plug, the method comprises the step of, arranging the setting adapter assembly between the plug and a setting tool; the setting adapter assembly comprising: a setting body; a crossover sub; a shear ring connecting the setting body and the crossover sub temporarily; a rotating dog carrier at a lower end of the setting body; a plurality of rotating dogs accommodated in the rotating dog carrier; an inner mandrel fixedly connecting with the crossover sub and extends through the shear ring, the setting body and coming into an inner chamber of the rotating dog carrier; wherein the rotating dogs are arranged at the bottom of the plug and in their vertical position to compress the plug during a process of setting the plug, and during a process of withdrawing the setting adapter assembly, the rotating dogs rotate 90 degrees into their horizontal position driven by the movement of the inner mandrel to allow the setting adapter assembly pass through the plug. running the setting tool loaded with the plug and the setting adapter assembly into the downhole; at a desired location, pushing a plug body of the plug downwardly with a first force while keeping the crossover sub staying still to set the plug; pushing the plug body of the plug downwardly with a second force to shear the shear ring; withdrawing the setting adapter assembly through the plug. 
     This setting adapter assembly simplifies the design of a plug by removing the need for a bottom cap and shear pins. 
     The setting adapter assembly also sets the frac plug from the bottom. This eliminates any tensile forces in the plug body. The elimination of tensile forces in the plug body allows the plug body to be thinner, thus allowing the plug inner diameter to be larger. This makes the plug smaller, cheaper and less complicated. 
     The foregoing has outlined rather broadly the features of the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter, which form the subject of the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the manner in which the above-recited and other enhancements and objects of the disclosure are obtained, a more particular description of the disclosure briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the disclosure and are therefore not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  is a perspective view of a plug coupled to a setting adapter assembly in accordance with an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view of  FIG. 1 ; 
         FIG. 3  is a perspective view of a rotating dog carrier; 
         FIG. 4  is a perspective view of a rotating dog; 
         FIG. 5  is a cross-sectional view of a plug and setting adapter assembly, wherein the plug is in the “Run in Hole” position; 
         FIG. 6  is a cross-sectional view of a plug and setting adapter assembly, wherein the plug is in the set position; 
         FIG. 7  is a cross-sectional view of a plug and setting adapter assembly, wherein the rotating dogs are in horizontal position; 
         FIG. 8  is a perspective view of a plug in a set position. 
         FIG. 9  is a cross-sectional view of the plug coupled to another embodiment of a setting adapter assembly in the first position or “Run-in-Hole” position. 
         FIG. 10  is a cross-sectional view of the plug and the setting adapter assembly in the second position with the setting adapter extracted from the plug. 
     
    
    
     Like elements in the various figures are denoted by like reference numerals for consistence. 
     DETAILED DESCRIPTION 
     The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present disclosure only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the disclosure. In this regard, no attempt is made to show structural details of the disclosure in more detail than is necessary for the fundamental understanding of the disclosure, the description taken with the drawings making apparent to those skilled in the art how the several forms of the disclosure may be embodied in practice. 
     The following definitions and explanations are meant and intended to be controlling in any future construction unless clearly and unambiguously modified in the following examples or when application of the meaning renders any construction meaningless or essentially meaningless. In cases where the construction of the term would render it meaningless or essentially meaningless, the definition should be taken from Webster&#39;s Dictionary 3 rd  Edition. 
     As used herein, the terms “up” and “down”; “upper” and “lower”; “upwardly” and downwardly”; “above” and “below”; and other like terms as used herein refer to relative positions to one another and are not intended to denote a particular direction or spatial orientation. the terms “radial” and “radially” include directions inward toward (or outward away from) the center axial direction of the item of oilfield equipment but not limited to directions perpendicular to such axial direction or running directly through the center. 
     The present application discloses a setting adapter assembly used in setting a plug in a well, more specifically, the setting adapter assembly is used in the setting process of a wireline set frac plug and is initially made up between a frac plug and a wireline setting tool. It sets the plug from the bottom, which eliminates any tensile forces in the plug body. The elimination of tensile forces in the plug body allows the plug body to be thinner, thus allowing the plug inner diameter to be larger. 
     Referring to  FIGS. 1 and 2 , an embodiment of the plug  200  and the setting adapter assembly disclosed herein is illustrated. The plug is coupled to the setting adapter assembly before being run into the wellbore, which allows the setting portions to be engaged at the surface. The setting adapter assembly  100  comprises a centrally located, elongated tubular setting body  110  of substantially uniform external diameter throughout its length and closed and terminating at its lower end by a rotating dog carrier  120 . The upper end of the body  110  is temporarily connected to a crossover sub  140  by a shear ring  150 . The crossover sub  140  is fixedly connected with a wireline setting tool (not shown). 
     The plug  200  includes a plug body  210  and a plug slip  220  disposed around the setting body  110 , intermediate the plug body  210  and the plug slip  220  is a plug seal  230 . The plug body  210  has a sloped outer surface  211 , such that when assembled on the setting body  110 , the outer diameter of the plug body  210  decreases in an axial direction toward the plug slip  220 . The slip  220  is disposed below the plug body  210  and has a sloped inner surface  223  (referring to  FIG. 3 ) adapt to rest on a complementary sloped outer surface  211  of the plug body  210 . As explained in more detail below, the slip  220  travel about the surface  211  the plug body  210 , thus expanding radially outward from the setting body  110  to engage an inner surface of a casing wall. 
     The slip  220  can include a plurality of slip segments  221  to engage an inner surface of a surrounding casing wall, as the slip  220  move radially outward from the setting body  110  due to the axial movement across the plug body  210 . Each of the slip segments  221  can be configured to be displaceable radically to secure the plug  200  in the well casing. The slip segments  221  can have a plurality of raised ridges  225 , which can be sized and shaped to bite into the casing wall. Thus, when an outward radial force is exerted on the slip, the plug body  210  can break the slip  220  into the separable slip segments  221  that can bite into the casing wall and wedge between the plug  200  and the casing wall. In this way, the slip segments  221  can secure the plug in a desired location in the casing. 
     The slip  220  can be formed of a material that is easily drilled or machined so as to facilitate easy removal of the plug  220  from a casing. For example, the slip  220  can be formed of a cast iron or composite material. 
     Referring to  FIGS. 1 to 3 , a plug seal  230  is disposed around the plug body  210 , the a plug seal  230  can have an outer diameter just slightly smaller than the diameter of a well casing (not shown) and can be compressible alone the longitudinal axis of the plug body  210  and radially expandable in order to form a seal between the plug body  210  and the casing wall in a wellbore. the plug seal  230  is a sealing element that prevent fluid from communicating between the upper and lower zone when a pressure differential is applied to the plug  200 . It may be formed from any material capable of expanding and sealing an annulus within the casing. and is preferably constructed of one or more synthetic materials capable of withstanding high temperatures and pressures, for example, elastomers, rubbers, blends and combinations thereof. 
     The upper end face of the plug body  210  contacts the lower end of a setting sleeve  300  of a wireline setting tool (not shown). The crossover sub  140  is accommodated in the setting sleeve  300 , the upper end of setting body  110  is surrounded by the setting sleeve  300  and the lower end of setting body  110  is surrounded by the frag  200 , thus the setting sleeve  300  and the frag  200  can freely slide alone setting body  110 . 
     The rotating dog carrier  120  is fixedly connected with the setting body  110 . The setting body  110  and the rotating dog carrier  120  are hollow structures, an inner mandrel  130  is fixedly connected with the crossover sub  140  and extends through the shear ring  150 , the setting body  110  and comes into the inner chamber  121  of the rotating dog carrier  120 . The inner mandrel  130  has a thorough channel, or path  131  along its central axis to allow fluid flow through thereof. Referring to  FIG. 3 , the bottom end of the rotating dog carrier  120  is a cone shaped member  124 , a thorough hole  125  is at the conical top to allow the fluid flow out of the setting adapter assembly  100 . 
     A plurality of thorough slots form dog carrier subs  123  along the circumference of the side wall  122  of the rotating dog carrier  120 . The dog carrier subs  123  are used to accommodate corresponding rotating dogs  400  configured to hold the slip  220  during the process of setting the plug  200  as described in greater detail further below. Referring to  FIG. 4 , each of the rotating dogs  400  comprise a setting tab  410  and a pivot pin  420  which can be configured to define an axis about which the setting tab  410  can be rotated. the setting tab  410  has two sidewalls  411 , 412  which are perpendicular, or at least substantially perpendicular, to the pivot pin  420 . In one embodiment, the setting tab  410  comprise two parallel, or at least substantially parallel planes  413 ,  414 , the two planes  413 ,  414  are further parallel, or at least substantially parallel to pivot pin  420 , wherein the plane  413  is longer than the plane  414 , such that the shapes of the two sidewalls  411 , 412  are trapezoids or substantial trapezoids. 
     The dog carrier subs  123  have slots  126  to accommodate the pivot pin  420  of the rotating dog  400 , The dog carrier subs  123  is configured that the setting tab  410  can be freely rotated around the pivot pin  420  clockwise from the position where the parallel planes  413 ,  414  are perpendicular to the axis of the inner mandrel  130  to the position where the parallel planes  413 ,  414  are parallel to the axis of the inner mandrel  130 , and when the parallel planes  413 ,  414  is parallel to the axis of the inner mandrel  130 , the parallel plane  413  is flush with the outer side surface of the rotating dog carrier  120 . 
     The inner mandrel  130  also provides a pocket  134  which is configured to accommodate a portion of the setting tab  410  when the setting tab  410  is located in the dog carrier subs  123  and the parallel planes  413 ,  414  are perpendicular to the axis of the inner mandrel  130 . The setting tab  410  has a tapered or ramped face  417 , the ramped face  417  is configured as such, when the parallel planes  413 ,  414  are perpendicular to the axis of the inner mandrel  130 , the sectional area of the setting tab  410  gradually increases from the center axis of the rotating dog carrier  120  to circumference of the side wall  122  of the rotating dog carrier  120 . 
     The bottom end  136  of the inner mandrel  130  is adjacent the pocket  134 , it has a tapered or ramped leading edge face  137  for engaging ramped face  417  of the setting tab  410 . Therefore, if the inner mandrel  130  moves upward, the bottom end  136  will drive the setting tab  410  rotate around the pivot pin  420  clockwise from the position where the parallel planes  413 ,  414  are perpendicular to the axis of the inner mandrel  130  to the position where the parallel planes  413 ,  414  are parallel to the axis of the inner mandrel  130 . The setting tab  410  is configured that the parallel plane  414  is flush with the inter side surface of the rotating dog carrier  120  when the parallel planes  413 ,  414  is parallel to the axis of the inner mandrel  130 . 
     Now referring to  FIG. 5 , the plug  200  is coupled to the setting adapter assembly  100  before being run into the wellbore. The rotating dogs  400  are initially in their vertical positions. The pivot pin  420  of each of the rotating dogs  400  is in the slots  126 . The parallel plane  413  is extended form the outer circumference of the plug slip  220  to the outer circumference of the pocket  134  and appress the bottom end surface of the plug slip  220 . The parallel plane  413  further contact the top surface of the pocket  134  such that the setting tab  410  cannot rotate clockwise. the setting tab  410  cannot rotate counterclockwise either because it is blocked by the bottom end  136  of the inner mandrel  130 . In this case, the plug  200  is sandwiched in between the setting sleeve  300  and the rotating dogs  400 . In an embodiment, the rotating dogs  400  distribute evenly along the circumference of the rotating dog carrier  120 . In a preferred embodiment, the number of the rotating dogs  400  is equal to that of the slip segments  221  of the plug slip  220 , and each of the setting tab  410  is against a corresponding slip segment  221  to ensure the force evenly. A setting tool (not shown) is run into a downhole in this assembled state, until the plug  200  reaches the desired position. 
     Referring to  FIG. 6 , at the desired position, the processes of setting the plug  200  and withdraw the adapter assembly  100  are divided into several stages according to different setting forces applied to the plug  200 . In the first stage, the setting tool urges the setting sleeve  300  to push the plug body  210  of the plug  200  downwardly with a first force while keeping the crossover sub  140  of the setting adapter assembly  100  staying still. The plug slip  220  bears stress and translates the push force to the setting tabs  410  of the rotating dogs  400 . The push force on the setting tab  410  can produce torque to make the setting tab  410  rotate clockwise around the pivot pin  420 , but the top surface of the pocket  134  stays still and produce torque to counteract the torque produced by the push force, therefore, the setting tabs  410  is against the plug slip  220  and keeps staying still. At the same time, the first setting force exerting on the plug  200  produces a tensile force on the shear ring  150 . The first setting force is smaller than the force required to shear the shear ring  150 . In this case, the setting sleeve  300  urges the plug body  210  to break the slip  220  into separable slip segments  221  at their predetermined break points and expand outwardly until the segments  221  have securely gripped the walls of the casing or wellbore wall with their ridges  225 . And further, the setting sleeve  300  continues to urge the plug body  210  to compress the plug seal  230  against the slip  220  and radially expand the plug seal  230  to form a seal between the plug body  210  and the casing wall in a wellbore, Thus the plug is set.  FIG. 8  shows the state of the plug in a set position. 
     In the second stage, the setting tool urges the setting sleeve  300  to push the plug body  210  of the plug  200  downwardly with a second force which is larger than the first force. Under the circumstances that the setting tabs  410  keeps staying still, the second force is translated to the setting body  110  through the rotating dog carrier  120 . Which will produce a tensile force on the shear ring  150 . The second force produce enough tensile to shear the shear ring  150  such that the shear ring  150  is broken at the position between the crossover sub  140  and the setting body  110 . 
     After the second stage, referring to  FIG. 7 . pulling upward the setting tool, the crossover sub  140  will pull the inner mandrel  130  upward. In this stage, the bottom end  136  of the inner mandrel  130  moves upward and drive the setting tab  410  rotate around the pivot pin  420  clockwise, this allows the setting tab  410  to rotate 90 degrees into their horizontal position within the dog carrier sub  123 . In this case, the parallel plane  413  is flush with the outer side surface of the rotating dog carrier  120  and the parallel plane  414  is flush with the inter side surface of the rotating dog carrier  120 . The rotating dog carrier  120  can be freely pulled through the plug  200 . 
     In order to locking the rotating dogs  400  into their horizontal position during the process of withdrawing the adapter assembly  100 , the bottom end  136  of the inner mandrel  130  will be keep in the rotating dog carrier  120  and the outer circumference of the bottom end  136  will abuts on the parallel plane  414  to keep the rotating dogs  400  into their horizontal position. To ensure the bottom end  136  be keep in the rotating dog carrier  120 , the adapter assembly  100  provide a travel restriction mechanism to limit the distance that the inner mandrel  130  can move in the setting body  110 . 
     Referring to  FIG. 2 , the travel restriction mechanism includes a locking ring  112  and a circumferential groove  114 . The locking ring  112  is located between the inner mandrel  130  and the setting body  110 , and can be embedded in a slot  113  in the inner surface of the setting body  110 . The slot  113  can be located adjacent the bottom end of the shear ring  150 . The circumferential groove  114  is a groove on the surface of the inner mandrel  130  with a certain length. The inner radius of the locking ring  112  is less than the radius of the inner mandrel  130  and cannot round the inner mandrel  130 , but it can round the circumferential groove  114  and slide on the circumferential groove  114 . In the initial state when the rotating dogs  400  are initially in their vertical positions, the locking ring  112  is on the upper end of the circumferential groove  114 . After the plug is set, and the shear ring  150  is sheared, the circumferential groove  114  will move upward following with the inner mandrel  130 , at this moment, the setting body  110  will not move and the locking ring  112  stays still, thus the locking ring  112  is on the bottom end of the circumferential groove  114 , when continuing to pull the inner mandrel  130  upward, the shoulder of the locking ring  112  will against the bottom surface of the circumferential groove  114  to prevent the relative motion between the inner mandrel  130  and the setting body  110 . In this case, the inner mandrel  130  will pull the whole setting adapter assembly upward. The length of the circumferential groove  114  is configured to allow the inner mandrel  130  to move from initial position to the position that the bottom end  136  will abuts on the parallel plane  414  to keep the rotating dogs  400  into their horizontal position. 
     All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this disclosure have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the disclosure. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims.