Patent Publication Number: US-2017350203-A1

Title: Electrically-Actuated Slip Devices

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to slip devices and arrangements for setting such devices within a wellbore or other surrounding tubular member. 
     2. Description of the Related Art 
     Slip devices, or slips, are typically devices used to mechanically anchor a work string within a wellbore. Slips can be incorporated into a work string and are often located adjacent to a packer element which can be set to provide a fluid seal within the wellbore. Slips normally include toothed slip elements that are radially moveable outwardly from an initial, unset position to a set position so that the teeth of the slip element will bite into the wellbore wall. Variations of slips can include scraper blocks or drag blocks which frictionally engage the sidewall of a wellbore or other tubular member but allow for some relative movement. 
     Traditionally, slips are set by axially moving a setting sleeve upon a mandrel. The setting sleeve is moved by applied hydraulic pressure. 
     SUMMARY OF THE INVENTION 
     The present invention relates to systems and methods for setting slip devices within a wellbore using electrical motive force, preferably provided from the surface. A first exemplary slip device in accordance with the present invention is described in context of a packer assembly which incorporates slip devices. An electric solenoid actuator is used to move the setting sleeve of the slip device. Alternative slip devices are described in which an electric solenoid actuator directly drives the slip element to its set position and wherein a setting piston is moved by the solenoid actuator to set the slip element. Slip devices are also described in which the slip elements are scraper or drag blocks which frictionally engage a surrounding tubular. Electrical power could be supplied to the solenoid actuator from surface via an electrical conduit. Alternatively, power is supplied to the solenoid actuator from a downhole power source. The force applied by the slip device is proportional to the current applied to the actuator. Particular embodiments include an electric current controller which is configured to control the amount of current provided to the solenoid actuator and thereby govern the setting force. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, wherein like reference numerals designate like or similar elements throughout the several figures of the drawings and wherein: 
         FIG. 1  is a side, cross-sectional view of a wellbore containing a work string with a slip device constructed in accordance with the present invention. 
         FIG. 2  is an enlarged, side cross-sectional view of the packer assembly which contains slip devices in accordance with the present invention. 
         FIG. 3  is an enlarged, side cross-sectional view of the packer assembly of  FIG. 2  now in a set condition. 
         FIG. 4  is a side, cross-sectional view of an alternative slip device constructed in accordance with the present invention. 
         FIG. 5  is a side, cross-sectional view of a further alternative slip device constructed in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The term “slip,” as used herein, is intended to refer broadly to elements which are moved outwardly from a wellbore work string and into engagement with a surrounding casing or tubing. A slip can be an anchoring-type slip which typically includes a toothed engagement surface for creating a biting engagement with the surrounding tubular. In addition, a slip could be a scraper block or drag block element which will engage the surrounding tubular frictionally. 
       FIG. 1  illustrates an exemplary wellbore  10  which has been drilled through the earth  12  from the surface  14 . The wellbore  10  is lined with metallic casing  16 . A work string  18  is disposed in the wellbore  10  from the surface  14 . The work string  18  may be a production arrangement, a work-over string or be of other configurations. The work string  18  includes a running string  20  which may be made up of convention oilfield tubulars or, alternatively, coiled tubing. The running string  20  may be used to carry and transport a bottom hole assembly (not shown) into the wellbore  10 , as is known in the art. 
     A packer assembly, generally indicated at  22  is incorporated into the running string  20  and is used to anchor the running string  20  within the wellbore  10 . The packer assembly  22  is shown in greater detail in  FIGS. 2 and 3 . Annular ring  24  is affixed to the running string  20  at the lower end of the packer assembly  22 . The ring  24  presents an upward axially-facing stop shoulder  26 . 
     The packer assembly  22  includes an annular, elastomeric, compression-set packer element  28  of a type known in the art which radially surrounds the running string  20 . A lower slip device  30  is located above the ring  24  and includes toothed slip element  32  and a setting ramp ring  34 . In the depicted embodiment, the slip element  32  is an annular member which will rupture when expanded radially outwardly. The lower slip device  30  is preferably located axially below the packer element  28 . The setting ramp ring  34  presents an angled ramp surface  35  which contacts the slip element  32 . When the setting ramp ring  34  is moved axially, the angled ramp surface  35  will urge the slip element  32  radially outwardly. 
     An upper slip device  36  is located axially above the packer element  28 . The upper slip device  36  includes toothed slip element  38  and a setting ramp ring  40 . Preferably, the slip element  38  and setting ramp ring  40  have the same construction as the slip element  32  and setting ramp ring  34  described previously. A setting sleeve  42  is adjacent to the slip elements  38  of the upper slip device  36 , and the ring  24  is adjacent the slip elements  32  of the lower slip device  30 . 
     An electrically-actuated solenoid actuator  44  surrounds the running string  20 . The solenoid actuator  44  generally converts electrical energy to linear movement of a plunger or piston member. The solenoid actuator  44  includes an electrical coil which is energized to move the plunger or piston member. An electrical conduit  46  extends from a power source  48  at surface  14  down to the solenoid actuator  44 . The power source  48  may be an electrical generator. The solenoid actuator  44  includes one or more actuating pistons  50  which is/are telescopically extendable from the actuator  44  to exert axial force upon the setting ring  42 . This force also causes the setting ramp rings  34 ,  40  to be moved axially upon the running string  20  to urge the slip elements  32 ,  38  radially outwardly and into biting engagement with the surrounding casing  16 . 
     In operation, the work string  18  is run into the wellbore  10  to a desired depth or location. During run-in, the packer assembly  22  is in the unset condition shown in  FIG. 2 . The packer assembly  22  is then moved from the unset position ( FIG. 2 ) to the set position ( FIG. 3 ) by energizing the solenoid actuator  44 . The packer element  28  and the upper, and lower slip devices  36 ,  30  are axially compressed. The slip elements  32 ,  38  are moved radially outwardly into anchoring engagement with the casing  16 . In addition, the packer element  28  is expanded radially outwardly into sealing engagement with the casing  16 . While the slip assemblies  30 ,  36  are described and shown anchoring a running string  20  within a wellbore  10 , it should be understood that the slip arrangements of the present invention are useful for anchoring any tubular member within a surrounding tubular member. 
       FIG. 4  depicts an alternative slip device  52  wherein a slip element  54  is driven directly by its solenoid actuator  56 . The solenoid actuator  56  is secured within a threaded opening  58  in a housing  60 . The housing  60  may be the outer housing of a downhole tool or a portion of a running string. The slip element  54  is preferably a generally cylindrical member which presents an engagement surface  62  which is toothed or otherwise shaped to bitingly engage the casing  16  when the slip element  54  is in a radially extended position. The slip element  54  resides within central opening  64  of the solenoid actuator  56  and is moveable between a radially contracted position (indicated by broken lines  54   a  in  FIG. 4 ) and a radially extended position (shown by the solid lines in  FIG. 4 ). When the solenoid actuator  56  is energized, the slip element  54  will be moved from the radially contracted position to the radially extended position. The solenoid actuator  56  is operably associated with a downhole power source  66 . As illustrated in  FIG. 4 , the downhole power source  56  is located within the flowbore  68  of the housing  60 . However, it may be placed in other downhole locations. The downhole power source  56  is preferably a battery which is capable of supplying a current of between about 4 to about 20 mA. Lead wires  70 ,  72  extend from the downhole power source  66  to the solenoid actuator  56  to deliver electric power. Preferably, the downhole power source  66  is controlled from surface  14  to energize the solenoid actuator  56  at a desired time. Control communication from surface  14  may be by wire (i.e., data line) or by wireless communication, as illustrated by broken line  68 . 
     In operation, the housing  60  with slip device  52  is disposed into the wellbore  10 . During run-in, the slip element  54  is in the radially contracted position depicted at  54   a . When the slip device  52  is at the desired depth or location within the wellbore  10 , the solenoid actuator  56  is energized to move the slip element  54  radially outwardly to its radially extended position and create biting engagement with the surrounding casing  16 . In preferred embodiments, the force used to urge the slip element  54  outwardly is proportional to the current that is applied to the solenoid actuator  56  by the downhole power source  66 . Therefore, an operator can increase the current that is provided to the solenoid actuator  56  in order to increase the setting force of the slip element  54 . 
       FIG. 5  illustrates a further alternative embodiment for a slip device  70  wherein scraper or drag block-type slip elements are extended radially outwardly from a housing by a solenoid actuator. The slip device  70  includes a generally cylindrical tool housing  72  which may be incorporated into or affixed to a running string, such as running string  20 . An upper central bore  74  is formed within the tool housing  72 . A lower central bore  76  is also formed within the tool housing  72 . The lower central bore  76  preferably has a larger diameter than the upper central bore  74 . Lateral windows  78  are formed within the tool housing  72 . In the depicted embodiment, there are two lateral windows  78 . However, there may be more or fewer than two such lateral windows, if desired. In preferred embodiments, the lower end of each lateral window  78  provides an angled ramp surface  80 . A scraper or drag blocks  82  are disposed within each of the lateral windows  78 . Each of the scraper or drag blocks  82  can move between radially contracted positions and radially extended positions. Each of the scraper or drag blocks  82  are preferably wedge shaped and present an outer contact surface  84  which will frictionally contact and slide upon surrounding casing  16  when in its radially extended position. 
     A solenoid actuator  56  is secured within a threaded opening  86  in the housing  72  just below the upper central bore  74 . A downhole power supply  66  is operably interconnected with the solenoid actuator  56  to supply current to the solenoid actuator  56 . The downhole power supply  66  is preferably located within the upper central bore  74 . A wired or wireless communication line  68  extends to surface  14  from the downhole power supply  66 . A piston member  86  is moved by the solenoid actuator  56 . The piston member  86  includes an enlarged piston head  88  and a shaft portion  90 . The shaft portion  90  resides within the central opening  64  of the solenoid actuator  56 . The enlarged piston head  88  presents angled ramp surfaces  92  which contact the scraper or drag blocks  82 . When the solenoid actuator  56  is energized, the piston member  86  is moved downwardly in the direction of arrow  94 . As the piston member  86  is moved downwardly, the scraper or drag blocks  82  are urged radially outwardly as illustrated by the arrows  96  toward their radially extended positions. Interaction of the angled ramp surfaces  92  and  80  with the wedge shaped blocks  82  will cause the scraper or drag blocks  82  to their radially extended positions and into contact with the surrounding casing  16 . 
     In operation, the slip device  70  is run into the wellbore  10 . When the slip device  70  is at a desired depth or location within the wellbore  10 , a command is sent via communication line  68  to the downhole power source  66 . The downhole power source  66  is turned on to energize the solenoid actuator  56  and cause the piston member  86  to move downwardly, thereby urging the scraper or drag blocks  82  radially outwardly and into contact with the surrounding casing  16 . The scraper or drag blocks  82  will function to arrest movement of the slip device  70  within the wellbore  10 . 
     It is noted that in each of the previously described embodiments, an operator may adjust the setting force used to set the slip element or scraper or drag block by adjusting the amount of current that is provided to the solenoid actuator  44  or  56 . Typically, an operator would determine a specific level of setting force for setting of the slip element  32 ,  38 ,  54  or  82 . Ordinarily, a lesser setting force would be desired for a scraper or drag block slip element, such as slip elements  82 . A greater setting force would be desired to create a biting engagement of an anchoring slip element, such as toothed slip elements  32 ,  38  or  54 . Current can then be governed to result in an appropriate level of setting force to the slip element(s)  32 ,  38 ,  54  or  82 . One mechanism for governing the level of current is a current controller ( 98  in  FIGS. 4-5 ) in the form of a downhole communications module which is operably associated with the downhole power source  66  and configured to control the level of current which is provided from the downhole power source  66  to the solenoid actuator  56 . Communication from surface  14  with the current controller  98  is indicated by the broken line  100  in  FIGS. 4-5 . Communication may be via physical data line, wireless or pressure pulse sequence or by other communication techniques known in the art. The downhole current controller  98  is configured to control the amount of current that is transmitted from the downhole power source  66  to the solenoid actuator  56 . This mechanism may be a rheostat or electronic circuitry which is capable of controlling the amount of current that is transmitted to the solenoid actuator  56 . A current controller device  98  may also be used with the arrangement of  FIGS. 1-3  and would be preferably located at surface  14  and operably associated with the power source  48 . 
     In certain aspects, the invention provides methods for setting a slip device within a surrounding tubular, such as casing  16 , within a wellbore  10 . In accordance with these methods, a slip device  30 ,  36 ,  52  or  70  is run into a wellbore  10 . A solenoid actuator  44  or  56  is then energized to move a slip element  32 ,  38 ,  54  or  82  from a radially contracted position to a radially extended position. Electrical power is provided to the solenoid actuator  44  or  56  from a power source  48  or  66  in order to energize the solenoid actuator  44 ,  56 . In accordance with particular embodiments, the setting force used to set the slip element  32 ,  38 ,  54  or  82  is controlled by adjustment of current provided to the solenoid actuator  44  or  56 . 
     Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow and any equivalents thereof.