Patent Publication Number: US-9890604-B2

Title: Devices and related methods for actuating wellbore tools with a pressurized gas

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from U.S. Provisional Application Ser. No. 61/975,585 filed on Apr. 4, 2014, the entire disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     1. Field of Disclosure 
     The present disclosure relates to an apparatus and method for actuating a downhole tool with a pressurized gas. 
     2. Description of the Related Art 
     During the construction, completion, recompletion, or work-over of oil and gas wells, there may be situations wherein one or more well tools may need to be mechanically actuated in situ. One known method for actuating a well tool is to generate a pressurized gas using a pyrotechnic charge and then convey the pressurized gas into a device that converts the pressure into mechanical energy, e.g., a piston-cylinder arrangement that converts the pressure into motion of a selected tool or tool component. In certain situations, the energetic material used to generate the pressurized gas may also produce debris in sufficient size and volume to partially or completely plug the passages that convey the pressurized gas to the actuator. In aspects, the present disclosure addresses the need for devices and methods for reducing the occurrence of plugging of these passages by the debris associated with deflagration of energetic materials. 
     SUMMARY OF THE DISCLOSURE 
     An apparatus for activating a wellbore tool may include a first sub having a first chamber and a second chamber; a igniter disposed in the first chamber, the igniter generating a flame output when ignited; a power charge disposed in the second chamber, the power charge generating a high pressure gas when ignited by the flame output; a gas transfer sub connectable with the first sub, the gas transfer sub having: a first end receiving a portion of the power charge, a longitudinal bore, and a plurality of flow passages radiating from the longitudinal bore, the plurality of flow passages providing fluid communication between the longitudinal bore and the second chamber of the first sub; and a second sub connectable with the gas transfer sub. The second sub may include a shaft having a first end connectable with the gas transfer sub, the shaft including: a passage in fluid communication with the longitudinal bore of the gas transfer sub and a face, and a piston positioned adjacent to the face, wherein a pressure chamber is formed between the shaft face and the piston is in fluid communication with the passage of the shaft. 
     The above-recited examples of features of the disclosure have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject of the claims appended hereto. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For detailed understanding of the present disclosure, references should be made to the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals and wherein: 
         FIGS. 1A-B  is a schematic sectional view of one embodiment of a gas energized well tool according to one embodiment of the present disclosure; 
         FIG. 2  is a sectional side view of a gas transfer sub in accordance with one embodiment of the present disclosure; 
         FIG. 3  is a sectional side view of a gas transfer sub in accordance with another embodiment of the present disclosure; and 
         FIG. 4  depicts an elevation view of a well using a well tool in accordance with one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     As will become apparent below, the present disclosure provides an efficient device for actuating well tools using pressurized gas. As will be appreciated, the present disclosure is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present disclosure with the understanding that the present disclosure is to be considered an exemplification of the principles of the present disclosure, and is not intended to limit the disclosure to that illustrated and described herein. 
     Referring  FIGS. 1A-B , there is shown one embodiment of a well tool  100  according to the present disclosure. Although  FIGS. 1A-B  are depicted as separate drawings, they represent a continuous interconnected well tool  100 . The well tool  100  may include an upper sub  110  ( FIG. 1A ), a gas transfer sub  130  ( FIG. 1A ), and a lower sub  160  ( FIG. 1B ). The well tool  100  may include an upper sub  110 , a gas transfer sub  130 , and a lower sub  160 . The term “sub” is intended to generically refer to a section or a portion of a tool string. While a sub may be modular and use threaded connections, no particular configuration is intended or implied by the use of the term sub. Generally, the upper sub  110  generates a high-pressure gas that is conveyed by the gas transfer sub  130  to the lower sub  160 . In this embodiment, the lower sub  160  uses the high-pressure gas to axially displace an actuator  162 , which may be attached to a separate wellbore device (not shown). The lower sub  160  and the actuator  162  may be used to axially displace or otherwise move, shift, or load a separate wellbore device (not shown), which may be a packer, a swage, a bridge plug, etc. 
     Referring to  FIG. 1A , in one configuration, the upper sub  110  includes a housing  112  that has a first chamber  114  and a second, larger chamber  116 . An igniter  118  is positioned in the first chamber  114  and a power charge  120  is positioned in the second chamber  116 . In one non-limiting embodiment, the igniter  118  may be a pyrotechnic device that generates a flame output when detonated by a suitable signal (e.g., electrical signal, hydraulic pressure, impact, etc.). The power charge  120  may be formed of an energetic material  122  that undergoes a low-order deflagration when ignited by the flame output of the igniter  118 . The energetic material  122  may be housed in a tube  124  formed of a combustible material such as cardboard or non-combustible materials such as metals and plastic. The low-order deflagration generates a gas at sufficient pressure and with enough volume to energize the lower sub  160 . The low-order deflagration may also produce debris in the form of solids, liquids, plasmas, gels, and mixtures thereof. Moreover, liquid debris may solidify soon after deflagration. 
     Referring to  FIGS. 1A and 2 , the gas transfer sub  130  transfers the gas generated by the upper sub  110  to the lower sub  160  ( FIG. 1B ). The gas transfer sub  130  may include a cylindrical body  134  that has an input end  136  and an output end  138 . The input end  136  includes a cup  140  that projects into the second chamber  116 . The cup  140  has an interior cavity  141  for receiving and enclosing at least a portion of the power charge  120 . The cup  140  generally aligns the power charge  120  with a longitudinal axis  132  of the upper sub  110  and centers the power charge  120  in the second chamber  116 . 
     The input end  136  also includes a plurality of passages  142  that extend between an outer surface  144  of the input end  136  to a longitudinal bore  146 . The passages  142  are the only paths of fluid communication at the input end  136  with the longitudinal bore  146 . Thus, gas from the second chamber  116  first flows along an annular flow space  121  formed by the outer surface of the cup  144  and an inner surface of the housing  112 . This annular flow space  121  may act as a preliminary filter. Thereafter, the gas flows through the passages  142  and converges into the bore  146 , which directs the gas to the output end  138 . In one arrangement, the passages  142  circumferentially distributed around and radiate in a spoke-like fashion from the bore  146  at an acute angle relative to the longitudinal axis  132 . In embodiments, the diameter of the passages  142  is smaller than the diameter of the longitudinal bore  146 . In embodiments, the inlets of the passages  142  are formed on an outer circumferential surface defining the cup  140 . 
     The input end  136  and the output end  138  may each include threads or other fastening features to connect with the upper sub  110  and the lower sub  160 , respectively. Additionally, seals may be used at the connections to ensure a sealed and fluid-tight environment for the bore  146 . 
     Referring now to  FIG. 1B , the second sub  160  uses the gas to energize one or more piston assemblies to energize the actuator  162 . By “energize,” it is meant the gas furnishes the energy required for the actuator  162  to perform one or more predetermined tasks. In the non-limiting arrangement shown, the second sub  160  has two piston assemblies that move in unison: a first piston assembly  164  and a second piston assembly  166 . The first piston assembly  164  includes a housing  168 , a shaft assembly  170 , and a piston  172 . The shaft assembly  170  includes a first end  174 , a flow passage  178 , and a face  180 . The first end  174  is received into the gas transfer sub bore  146  ( FIG. 1A ) of the body  134  ( FIG. 1A ) such that the gas transfer sub bore  146  and the flow passage  178  are in fluid communication. The flow passage  178  extends fully through the shaft assembly  170  and terminates at a cavity  184  formed at a second end  186  of the shaft assembly  170 . A pressure chamber  182  formed between the face  180  and the piston  172  receives the gas via the flow passage  178 . 
     Similarly, the second piston assembly  166  includes a housing  188 , a shaft assembly  190 , and a piston  192 . The shaft assembly  190  includes a first end  194  that is received into the cavity  184  of the shaft assembly  170 , a flow passage  196 , and a face  198 . A pressure chamber  200  formed between the face  198  and the piston  192  receives the gas via the flow passage  196 . The actuator  162  may be connected to a second end  202  of the shaft assembly  190 . The actuator  162  has a distal end that can connect to the separate work piece (not shown). The housing  188  connects to a movable component  199  of the separate work piece (not shown) 
     Referring now to  FIG. 3 , there is shown another embodiment of a flow transfer sub  130 . In this embodiment, an input end  232  has a pedestal  234  and orthogonal passages  236  radiating outward from a central bore  238 . The power charge  120  ( FIG. 1A ) seats on but is not retained by the pedestal  234 . In a manner previously described, the orthogonal passages  236  filter the gas generated by the power charge  120  ( FIG. 1A ). In embodiments, the inlets of the passages  236  are formed on an outer circumferential surface defining the input end  232 . 
     Referring to  FIG. 4 , there is shown a well construction and/or hydrocarbon production facility  20  positioned over a subterranean formation of interest  22 . A gas activated well tool  100  made in accordance with the present disclosure may be used to perform one or more predetermined downhole tasks in a wellbore  25  that intersects the formation  22 . The facility  20  can include known equipment and structures such as a platform  26  at the earth&#39;s surface  28 , a rig  30 , a wellhead  32 , and cased or uncased pipe/tubing  34 . A work string  36  is suspended within the wellbore  25  from the platform  26 . The work string  36  can include drill pipe, coiled tubing, wire line, slick line, or any other known conveyance means. The work string  36  can include telemetry lines or other signal/power transmission mediums that establish one-way or two-way telemetric communication from the surface to the downhole tool  100  connected to an end of the work string  36 . For brevity, a telemetry system having a surface controller (e.g., a power source)  38  adapted to transmit electrical signals via a cable or signal transmission line  40  disposed in the work string  36  is shown. 
     As used above, the word “deflagration” refers to a process where an energetic material does not generate a shock wave when ignited. 
     In one method of operation, the well tool  100  is conveyed into the wellbore  25  using the work string  36 . After being positioned as desired, a suitable signal is transmitted to detonate the igniter  118 . In one non-limiting arrangement, an electrical signal is conveyed via the cable  40 . Alternatively, a pressure increase or drop bar may be used. The igniter  118  generates a flame output that ignites the power charge  120 . The power charge  120  undergoes a low order deflagration that generates a high-pressure gas. Solid or semi-solid debris may also be formed during the low order-deflagration. The gas flows parallel with the longitudinal axis  132  along the second chamber  116  and the annular flow space  121  and then flows radially inward into the flow passages  142 . The flow passages act as filters that prevent debris above a predetermined size from entering the longitudinal bore  146 . The high-pressure gas flows via the longitudinal bore  146  to the first pressure chamber  182  and also via the longitudinal bore  196  to the second pressure chamber  200 . 
     When the pressures in the chambers  182 ,  200  are sufficiently high, the pistons  172 ,  192  are displaced in the direction shown by arrows  197 . Thus, the housings  168 ,  188  are also displaced in a similar direction. The distal end  162  is fixed to the separate work piece (not shown). Thus, the shaft assemblies  170 ,  190  hold the well tool  100  stationary relative to portion of the separate work piece (not shown) that must stay stationary while the movable portion  199  is axially displaced by the housing  188 . It is the axial movement of the movable portion  199  that activates the separate well tool (not shown). It should be appreciated that the gas supplied to the pressure chambers  182 ,  200  have a reduced content of debris, which correspondingly reduces the risk that the various passages and bores conveying the gas become obstructed. 
     It should also be appreciated the  FIGS. 1A-B  embodiment also reduces the risk of liquid debris entering the bores and passages. For example, referring to  FIG. 1A , when the well tool  100  approaches a horizontal orientation, liquid debris will collect in a tool low side  195  and resist flowing in the longitudinal bore  146 . This is due to the longitudinal bore  146  being at a higher elevation than the tool low side  195 . Also, for orientations of well tool  100  approaching a vertical, the cup  140  can retain and capture liquid debris. 
     The foregoing description is directed to particular embodiments of the present disclosure for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope of the disclosure. Thus, it is intended that the following claims be interpreted to embrace all such modifications and changes.