Patent Publication Number: US-2023160282-A1

Title: Catching dropped tubulars

Description:
TECHNICAL FIELD 
     This disclosure relates to catching piping strings on rigs. 
     BACKGROUND 
     During wellbore operations, such as tripping tubing, piping, or casing into a wellbore, tubulars are lowered into the wellbore and restrained while an additional tubular is attached to the tubular string. In such situations, the string is restrained by a hydraulic spider. A hydraulic spider defines a passage through which the tubular sections are passed. The spider includes hydraulic “legs” that extend into the opening to support and restrain the tubular string. 
     SUMMARY 
     This specification describes technologies relating to catching dropped tubulars. 
     An example of the subject matter described within this disclosure is a rig safety device with the following features. A rotatable plate is configured to be coupled to a rotary table of a rig floor. The rotatable plate defines a central passage through which a tubular can be passed. Multiple arms each have a first end rotably coupled to the rotatable plate. The arms are hinged such that a distal end of the arms, away from the rotatable plate, are configured to move towards or away from the passage. Each of arms extends away from the rotatable plate towards the passage. The arms are biased away from the passage. Rollers are rotably coupled to one of the distal ends of the arms. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. The rotatable plate defines a plurality of grooves corresponding to each of the plurality of rollers. The grooves are sized to receive the rollers. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. The rollers and the rotatable plate include carbon steel. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. The rollers include four rollers. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. The arms include twice the number of rollers. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. The angle bias further includes an angle bias biasing an angle of each of the plurality of arms relative to the rotatable plate. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. Each of the arms includes a cylinder nearer the rotatable plate than the distal end. A pin is at the distal end of the arm. The pin is radially retained by the cylinder. An axial bias biases the pin away from the cylinder. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. The axial bias includes a coiled metal spring. 
     Aspects of the example rig safety devices, which can be combined with the rig safety device alone or in combination with other aspects, include the following. A surface of the roller includes a rough texture. 
     An example implementation of the subject matter described by this disclosure is a method of catching a dropped vertical tubular. The method has the following features. A clamp, carried by a tubular, is contacted by a roller, as a tubular on which the clamp is attached falls at an uncontrolled rate. The roller is guided by the clamp towards a rotatable plate supporting the roller in response to contacting the clamp. The rotatable plate interferes with the roller and the clamp in response to guiding the roller. The uncontrolled fall is ceased in response to interfering with the roller and the clamp. 
     Aspects of the example method, which can be combined with method alone or in combination with other aspects, include the following. The clamp is received by the tubular. 
     Aspects of the example method, which can be combined with method alone or in combination with other aspects, include the following. The tubular is removed from the roller and rotatable plate after the uncontrolled fall has been ceased. 
     Aspects of the example method, which can be combined with method alone or in combination with other aspects, include the following. The tubular is a first tubular. The clamp is a first clamp. The method further includes the following features. The clamp is removed from the first tubular. The first tubular is lowered in a controlled manner. A second tubular is received by the first tubular. The clamp, or a second, identical clamp, is received by the second tubular. 
     Aspects of the example method, which can be combined with method alone or in combination with other aspects, include the following. The rollers are bound by a rough surface of the rollers and a rough surface of the rotatable plate. 
     An example implementation of the subject matter described within this disclosure is a rig system with the following features. A clamp is attached to and encircles a vertical tubular. A rotary table defines a portion of a passage through which the tubular is passed. A catching device is above and supported by the rotary table. The catching device is configured to rotate in unison with the rotary table. The catching device includes the following features. A rotatable plate defines a second portion of the passage through which the tubular is passed. Arms extend away from the rotatable plate towards the passage. The arms are biased away from the passage. The arms are hinged such that a distal end of each of the arms, away from the rotatable plate, is configured to move towards or away from the passage. Rollers are at distal ends of the arms. Each of the rollers is supported by two of the plurality of arms. 
     Aspects of the example rig system, which can be combined with example rig system alone or in combination with other aspects, include the following. The rotatable plate defines grooves corresponding to each of the plurality of rollers. The grooves are sized to receive the rollers. 
     Aspects of the example rig system, which can be combined with example rig system alone or in combination with other aspects, include the following. The rollers and the rotatable plate include carbon steel. 
     Aspects of the example rig system, which can be combined with example rig system alone or in combination with other aspects, include the following. The rollers include four rollers. 
     Aspects of the example rig system, which can be combined with example rig system alone or in combination with other aspects, include the following. An angle bias biases an angle of each of the arms relative to the rotatable plate. The angle bias includes a coiled metal spring. 
     Aspects of the example rig system, which can be combined with example rig system alone or in combination with other aspects, include the following. Each of the arms includes the following features. A cylinder is nearer the rotatable plate than the distal end. A pin is at the distal end of the arm. The pin is radially retained by the cylinder. An axial bias biases the pin away from the cylinder. 
     Aspects of the example rig system, which can be combined with example rig system alone or in combination with other aspects, include the following. The axial bias includes a coiled metal spring. 
     Particular embodiments of the subject matter described in this specification can be implemented so as to realize one or more of the following advantages. The subject matter allows tubulars to be caught during uncontrolled drops. Catching the tubulars prior to the tubulars falling fully into the wellbore prevents delays in wellbore operations. 
     The details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an example rig safety device. 
         FIG.  2    is a side cross-sectional schematic diagram of an example rotary table with the example rig safety device installed. 
         FIG.  3 A  is a side cross-sectional view of an example roller and arm of the example rig safety device. 
         FIG.  3 B  are examples of rough surfaces that can be used on the roller or grooves of a rotatable plate of the example rig safety device. 
         FIG.  4    is a flowchart of an example method that can be used with aspects of this disclosure. 
         FIGS.  5 A- 5 B  are perspective views of the example rig safety device in various stages of operation. 
     
    
    
     Like reference numbers and designations in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     During tripping operations, a tubular can sometimes be dropped in an uncontrolled manner. This results in a tubular falling into a wellbore, requiring extensive fishing operations to retrieve the dropped string. The fishing operations can extend wellbore operations significantly, causing delays. The spider does not actuate quickly enough to catch and restrain the tubular when such a situation presents itself. 
     This disclosure relates to a tubular safety device on a rig floor. The device includes spring loaded arms with rollers. The arms are pivotable towards a hole in the rig floor through which tubulars are fed. The tubulars include a removable safety clamp. In instances where the tubular is dropped, the rollers interfere with the removable safety clamp to catch the dropped tubular. 
       FIG.  1    is a perspective view of an example rig safety device  100 . The rig safety device  100  includes a rotatable plate  102  configured to be coupled to a rotary table of a rig floor. The rotatable plate  102  defines a central passage  104  through which a tubular, such as casing, can be passed. The rotatable plate  102  defines a plurality of grooves  106  corresponding to each of the rollers  108 . The grooves are sized to receive the rollers  108 . That is, the grooves  106  are dimensionally (length and width) large enough to receive the rollers  108  during a drop scenario. 
     The rollers  108  are connected to the rotatable plate  102  by arms  110  each having a first end  114  rotably coupled to the rotatable plate  102 . Each of the arms  110  is hinged such that a distal end  112  of the arms  110 , that is, ends away from the rotatable plate, are configured to move towards the central passage  104  or away from the passage  104 . Each of the arms  110  extend away from the rotatable plate. In some implementations, the arms extend towards the central passage  104 . The arms  110  are biased away from the central passage  104 . Additional details on the arms  110  are described throughout this disclosure. 
     The rollers  108  are rotably coupled to the distal ends  112  of the arms  110 . In the illustrated implementation, the rig safety device includes four rollers  108  with two arms  110  supporting each roller  108 . Other numbers of rollers  108  and arms  110  per roller can be used without departing from this disclosure. For example, two, three, or five rollers  108  can be used without departing from this disclosure. For arms  110 , one or three arms  110  can be used with each roller, for example, without departing from this disclosure. 
     Components within the rig safety device  100  are constructed of robust materials, such as carbon steel. The components within the rig safety device, such as the rollers  108  and the rotatable plate  102 , can endure a number of dropped tubulars before being replaced. For example, the components can be rated to sustain four drops. 
       FIG.  2    is a side cross-sectional schematic diagram of an example rotary table  202  with the example rig safety device  100  installed. The rotary table  202  defines a second portion of a passage  104  through which the tubular is passed. The rig safety device  100  is coupled to the rotary table  202 , by the flush-mounted spider  204 . In some implementations, the rig safety device is fastened to the flush-mounted spider  204 , for example, with bolts. The flush-mounted spider  204  defines a third portion of the passage  104  through which the tubular is passed. The rig safety device  100 , the flush-mounted spider  204 , and the rotary table  202  are arranged to rotate in unison with one another. The rig safety device  100  itself includes a body  206  in which the tapered rotatable plate  102  rests and is centered. 
       FIG.  3 A  is a side cross-sectional view of an example roller  108  and arm  110  of the example rig safety device  100  ( FIG.  1   ). The arm includes an angle bias  302  pivotally biasing the arm  110  away from the opening configured to receive the tubular  305 . In some implementations, the angle bias  302  is a metal spring. Other biases can be used without departing from this disclosure, for example, a torsion spring, a compression spring, a tension spring, an air spring, or an elastomer spring. 
     Each of the arms  110  themselves are made up of a variety of components. For example, a cylinder is nearer the rotatable plate  102  ( FIG.  1   ) than the distal end  112 . In some implementations, the cylinder can include the hinged end  114 . At the distal end of the cylinder is a pin  304 . The pin  304  is radially retained by the cylinder  306 . In some implementations, the pin  304 , the cylinder  306 , or both can include a shoulder, tab, or other interference geometry to retain an end of the pin  304  within the distal end of the cylinder  306 . The pin  304  itself is at the distal end of the arm  110 . 
     The cylinder  306  itself defines a chamber in which an axial bias  308  biases the pin  304  away from the cylinder  306 . In some implementations, the axial bias  308  includes a coiled metal compression spring. Other biases can be used without departing from this disclosure, for example, a torsion spring, a compression spring, a tension spring, an air spring, or an elastomer spring. 
     The roller  108  is connected to one or more pins  304  by a retaining pin. This pin radially retains the roller while the arms axially constrain the roller  108 . In some implementations, each of the rollers includes a rough textured surface. In some implementations, the grooves can include a similar rough texture. In such implementations, the rollers may bind with the texture in the grooves to prevent rolling during catching operations. 
       FIG.  3 B  illustrates examples of rough surfaces that can be used on the roller  108  or grooves  106  of a rotatable plate  102  of the example rig safety device  100 . Rough surface  352  includes raised dots extending from the surface. Rough surface  354  includes protrusions extending from the surface. These protrusions have a height greater than that of the dots of surface  352 . Rough surface  356  includes grooves. In some implementations, the grooves extend perpendicular to the direction of rotation of the rollers ###. Rough surface  358  includes lengths of tubes extending from the surface. Rough surface  360  is a surface with negative features, that is, material is removed from the surface to define pits. Rough surface  362  includes an intricate matrix. The intricate matrix is similar to the grooves of surface  356 ; however, material is removed perpendicular to the grooves to produce a grid-like surface. All of the rough surfaces described herein can be manufactured and added to components in a variety of ways, for example, additive manufacturing techniques, such as weld overlay or 3D printing, or traditional machining techniques, such as milling. Alternatively or in addition, surface components can be added to existing surfaces, for example, the protrusions of surface  354  or the tubes of surface  385  can be welded, epoxied, or otherwise fastened to a surface of a component. 
       FIG.  4    is a flowchart of an example method  400  that can be used with aspects of this disclosure. The flowchart is discussed in context with  FIGS.  5 A- 5 B , which are perspective views of the example rig safety device in various stages of operation. 
     In the illustrated scenario, a vertical tubular is being passed through the rig safety device  100 . Prior to inserting the tubular through the rig safety device  100 , a clamp  502  is received by and encircles the tubular  305 . Several types of clamps can be used without departing from this disclosure. For example, a T-type clamp, a C-type clamp, or an MP-type clamp can be used. 
     In instances where the tubular is dropped, at  402 , the clamp  502 , carried by the tubular  305 , is contacted by the rollers  108 . That is, when the tubular falls at an uncontrolled rate, the clamp makes contact with the rollers. At  404 , the roller  108  is guided by the clamp  502  towards the rotatable plate  102  in response to contact with the clamp  502 . In some implementations, the clamp  502  guides the roller into the grooves  106 . At  406 , the rotatable plate  102  interferes with (blocks) the roller  108  and the clamp  502  in response to guiding the roller  108 . At  408 , the uncontrolled fall is ceased in response to interfering with the roller  108  and the clamp  502 . After the uncontrolled fall has been ceased, the tubular  305  is removed from the rollers  108  and rotatable plate  102 . 
     Under normal operations, the clamp  502  is removed from the tubular  305  once the tubular  305  has been lowered through the passage  104  to a desired depth. A second tubular is then received by an uphole end of the first tubular  305 . The clamp or a second, identical clamp, is then received by the second tubular, and the process is repeated. 
     While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. 
     Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products. 
     Thus, particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results.