Devices, systems, and methods for selectively engaging downhole tool for wellbore operations

Abstract

A device for wellbore operations is configured to self-determine its downhole location in a wellbore in real-time and to self-activate upon arrival at a preselected target location. The device determines its downhole location based on magnetic field and/or magnetic flux signals provided by an onboard three-axis magnetometer. The device optionally comprises one or more magnets. The magnetometer detects changes in magnetic field and/or magnetic flux caused by the device's proximity to or passage through various features in the wellbore. The device can self-activate to deploy an engagement mechanism to engage a target tool downhole from the target location. The engagement mechanism comprises a seal supported by two expandable support rings, each having a respective elliptical face for engagement with the elliptical face of the other support ring.

What is claimed is: 
     
         1 . A method comprising:
 deploying a device into a passageway of a tubing string;   measuring, by a magnetometer in the device, an x-axis magnetic field in an x-axis, a y-axis magnetic field in a y-axis, and a z-axis magnetic field in a z-axis, the z-axis being parallel to a direction of travel of the device, and the x-axis and y-axis being orthogonal to the z-axis and to each other;   generating one or more of: an x-axis signal based on the x-axis magnetic field, a y-axis signal based on the y-axis magnetic field, and a z-axis signal based on the z-axis magnetic field; and   monitoring one or more of the x-axis, y-axis, and z-axis signals to detect a change; and   analyzing the change to detect at least one feature in the tubing string,   wherein the change is caused by one of:   a movement of a first magnet in the device relative to a second magnet in the device;   proximity of the device to the at least one feature, each of the at least one feature being a magnetic feature; and   proximity of the at least one feature to a third magnet in the device.   
     
     
         2 . The method of  claim 1  wherein the change is caused by the movement of the first magnet relative to the second magnet, and the change comprises a change in the z-axis signal, and wherein analyzing comprises determining whether the change in the z-axis signal is greater than or equal to a predetermined threshold magnitude. 
     
     
         3 . The method of  claim 2  wherein analyzing comprises, upon determining that the change in the z-axis signal is greater than or equal to the predetermined threshold magnitude, determining whether the y-axis signal is within a baseline window during the change in the z-axis signal. 
     
     
         4 . The method of  claim 2  wherein analyzing comprises, upon determining that the change in the z-axis signal is greater than or equal to the predetermined threshold magnitude, determining whether the y-axis signal is within a baseline window during a maximum of the change in the z-axis signal. 
     
     
         5 . The method of  claim 3 or 4  wherein analyzing comprises, upon determining that the y-axis signal is within the baseline window, determining whether the y-axis signal is within the baseline window for longer than a threshold timespan. 
     
     
         6 . The method of any one of  claims 2 to 5  comprising adjusting a baseline of the y-axis signal based at least in part on the x-axis signal. 
     
     
         7 . The method of any one of  claims 2 to 6  wherein the first magnet and the second magnet are rare-earth magnets. 
     
     
         8 . The method of any one of  claims 2 to 7  wherein the first magnet is embedded in a first retractable protrusion of the device and the second magnet is embedded in a second retractable protrusion of the device, the first and second retractable protrusions positioned at about the same axial location on an outer surface of the device, and wherein the at least one feature comprises a constriction. 
     
     
         9 . The method of  claim 8  wherein the first and second retractable protrusions are azimuthally spaced apart by about 180°, and the y-axis is parallel to a direction of retraction of the first and second retractable protrusions. 
     
     
         10 . The method of  claim 1  wherein the change is caused by the proximity of the device to the at least one feature, and wherein monitoring comprises calculating an ambient magnetic field M using: 
       
         
           
             
               M 
               = 
               
                 
                   
                     
                       ( 
                       
                         x 
                         + 
                         c 
                       
                       ) 
                     
                     2 
                   
                   + 
                   
                     
                       ( 
                       
                         y 
                         + 
                         d 
                       
                       ) 
                     
                     2 
                   
                 
               
             
           
         
         where x is the magnitude of the x-axis signal, y is the magnitude of the y-axis signal, and c and d are adjustment constants for the x-axis and y-axis signals, respectively, and wherein the change comprises a change in the ambient magnetic field. 
       
     
     
         11 . The method of  claim 10  wherein analyzing comprises determining whether the change falls within a parameters profile of one of the at least one feature. 
     
     
         12 . The method of  claim 11  wherein the parameters profile comprises a minimum magnetic field threshold, and wherein determining whether the change falls within the parameters profile comprises determining whether the ambient magnetic field is greater than or equal to the minimum magnetic field threshold. 
     
     
         13 . The method of  claim 12  wherein the parameters profile comprises a maximum magnetic field threshold, and wherein determining whether the change falls within the parameters profile comprises:
 starting a timer upon determining that the ambient magnetic field is greater than or equal to the minimum magnetic field threshold; 
 monitoring, after starting the timer, the ambient magnetic field to determine whether the ambient magnetic field is less than the minimum magnetic field threshold or is greater than the maximum magnetic field threshold; and 
 stopping the timer upon determining that the ambient magnetic field is less than the minimum magnetic field threshold or is greater than the maximum magnetic field threshold, to provide an elapsed time between the starting of the timer and the stopping of the timer. 
 
     
     
         14 . The method of  claim 13  wherein the parameters profile comprises a minimum timespan and a maximum timespan, and wherein determining whether the change falls within the parameters profile comprises determining whether the elapsed time is between the minimum timespan and the maximum timespan. 
     
     
         15 . The method of  claim 1  wherein the change is caused by the proximity of the at least one feature to the third magnet, and wherein monitoring comprises calculating a magnetic field M of the third magnet using: 
       
         
           
             
               M 
               = 
               
                 
                   
                     
                       ( 
                       
                         x 
                         + 
                         p 
                       
                       ) 
                     
                     2 
                   
                   + 
                   
                     
                       ( 
                       
                         y 
                         + 
                         q 
                       
                       ) 
                     
                     2 
                   
                   + 
                   
                     
                       ( 
                       
                         z 
                         + 
                         r 
                       
                       ) 
                     
                     2 
                   
                 
               
             
           
         
         where x is the magnitude of the x-axis signal, y is the magnitude of the y-axis signal, z is the magnitude of the z-axis signal, and p, q, and r are the adjustment constants for x-axis, y-axis, and z-axis signals, respectively, and wherein the change comprises a change in the magnetic field of the third magnet. 
       
     
     
         16 . The method of  claim 15  wherein analyzing comprises determining whether the change falls within a parameters profile of one of the at least one feature. 
     
     
         17 . The method of  claim 16  wherein the parameters profile comprises a minimum magnetic field threshold, and wherein determining whether the change falls within the parameters profile comprises determining whether the magnetic field of the third magnet is greater than or equal to the minimum magnetic field threshold. 
     
     
         18 . The method of  claim 17  wherein the parameters profile comprises a maximum magnetic field threshold, and wherein determining whether the change falls within the parameters profile comprises:
 starting a timer upon determining that the magnetic field of the third magnet is greater than or equal to the minimum magnetic field threshold; 
 monitoring, after starting the timer, the magnetic field of the third magnet to determine whether the magnetic field of the third magnet is less than the minimum magnetic field threshold or is greater than the maximum magnetic field threshold; and 
 stopping the timer upon determining that the magnetic field of the third magnet is less than the minimum magnetic field threshold or is greater than the maximum magnetic field threshold, to provide an elapsed time between the starting of the timer and the stopping of the timer. 
 
     
     
         19 . The method of  claim 18  wherein the parameters profile comprises a minimum timespan and a maximum timespan, and wherein determining whether the change falls within the parameters profile comprises determining whether the elapsed time is between the minimum timespan and the maximum timespan. 
     
     
         20 . The method of any one of  claims 15 to 19  wherein each of the at least one feature is a magnetic feature or a thicker feature. 
     
     
         21 . The method of  claim 1  wherein each of the at least one feature is magnetic feature, and wherein a first feature of the at least one feature has a first parameters profile and a second feature of the at least one feature has a second parameters profile, the first parameters profile being different from the second parameters profile. 
     
     
         22 . The method of any one of  claims 1 to 21  comprising, upon detecting one of the at least one feature, one or both of: incrementing a counter; and determining a location of the device in the tubing string. 
     
     
         23 . The method of  22  comprising:
 prior to deploying the device, setting a target location; 
 after incrementing the counter and/or determining the location, comparing the counter or the location with the target location to determine whether the counter or the location has reached the target location; and 
 upon determining that the counter or the location has reached the target location, activating the device. 
 
     
     
         24 . The method of  claim 23  wherein activating the device comprises actuating an engagement mechanism of the device. 
     
     
         25 . The method of any one of  claims 1 to 24  comprising determining a distance travelled by the device based at least in part on an acceleration of the device measured by an accelerometer in the device. 
     
     
         26 . The method of  claim 25  wherein determining the distance is based at least in part on a rotation of the device measured by a gyroscope in the device. 
     
     
         27 . A downhole tool comprising:
 a first support ring having:
 a first face at a first end; 
 a first elliptical face at a second end, the first face and the first elliptical face having a first gap extending therebetween; and 
   a second support ring having:
 a second face at a first end; 
 a second elliptical face at a second end, the second elliptical face being adjacent to the first elliptical face and configured to matingly abut against the first elliptical face, the second face and the second elliptical face having a second gap extending therebetween, 
   the first and second support rings being expandable from an initial position to an expanded position, wherein in the expanded position, the first and second gaps are widened compared to the initial position.   
     
     
         28 . The downhole tool of  claim 27  wherein:
 the first support ring comprises:
 a first short side having a first short side length; and 
 a first long side having a first long side length, the first long side length being greater than the first short side length, and each of the first face and the first elliptical face extending from the first short side to the first long side; and 
 
 the second support ring comprises:
 a second short side having a second short side length; and 
 a second long side having a second long side length, the second long side length being greater than the second short side length, and each of the second face and the second elliptical face extending from the second short side to the second long side. 
 
 
     
     
         29 . The downhole tool of  claim 28  wherein the second long side length is equal to or greater than the first long side length. 
     
     
         30 . The downhole tool of  claim 28 or 29  wherein second short side length is equal to or greater than the first short side length. 
     
     
         31 . The downhole tool of  claim 28  wherein the second long side length is less than the first long side length. 
     
     
         32 . The downhole tool of  claim 28 or 31  wherein second short side length is less than the first short side length. 
     
     
         33 . The downhole tool of any one of  claims 28 to 32  wherein the first gap is positioned at or near the first short side. 
     
     
         34 . The downhole tool of any one of  claims 28 to 33  wherein the second gap is positioned at or near the second short side. 
     
     
         35 . The downhole tool of any one of  claims 28 to 34  wherein the second short side is positioned adjacent to the first long side; and the second long side is positioned adjacent to the first short side. 
     
     
         36 . The downhole tool of any one of  claims 27 to 33  wherein the first gap is azimuthally offset from the second gap. 
     
     
         37 . The downhole tool of any one of  claims 27 to 36  wherein one or both of the first and second faces are circular. 
     
     
         38 . The downhole tool of any one of  claims 27 to 37  wherein the first elliptical face is inclined at an angle ranging from about 1° to about 30° relative to the first face. 
     
     
         39 . The downhole tool of  claim 28  wherein one or more of:
 the first short side length is about 10% to about 30% of the first long side length; 
 the first short side length is about 18% to about 38% of the second short side length; and 
 the first short side length is about 3% to about 23% of the second long side length. 
 
     
     
         40 . The downhole tool of  claim 28  wherein one or more of:
 the second short side length is about 10% to about 30% of the second long side length; 
 the second short side length is about 18% to about 38% of the first short side length; and 
 the second short side length is about 3% to about 23% of the first long side length. 
 
     
     
         41 . The downhole tool of any one of  claims 27 to 40  wherein, in the expanded position, at least a portion of the first support ring is radially offset from the second support ring. 
     
     
         42 . The downhole tool of any one of  claims 27 to 41  wherein, in the expanded position, the first gap has less volume than the second gap. 
     
     
         43 . The downhole tool of any one of  claims 27 to 42  comprising a cone and an annular seal, and wherein the first support ring, the second support ring, and the seal are supported on an outer surface of the cone, the seal being adjacent to the first face. 
     
     
         44 . The downhole tool of  claim 43  comprising:
 an inactivated position in which the annular seal and the first and second support rings are at a first axial location of the cone, and the first and second rings are in the initial position; and 
 an activated position in which the annular seal and the first and second support rings are at a second axial location of the cone, and the first and second support rings are in the expanded position, 
 wherein an outer diameter of the second axial location is greater than an outer diameter of the first axial location, and an outer diameter of the annular seal is greater in the activated position than in the inactivated position. 
 
     
     
         45 . The downhole tool of  claim 43 or 44  wherein the first short side length is about 6% to about 26% of an axial length of the annular seal. 
     
     
         46 . The downhole tool of any one of  claims 43 to 45  wherein the second long side length is about 109% to about 129% of an axial length of the annular seal. 
     
     
         47 . The downhole tool of any one of  claims 43 to 26  wherein the first and second support rings each have a respective frustoconical inner surface for matingly abutting against the outer surface of the cone. 
     
     
         48 . The downhole tool of any one of  claims 43 to 47  wherein one or both of the first and second support rings comprise a dissolvable material.