Devices, Systems, and Methods for Selectively Engaging Downhole Tool for Wellbore Operations

This application claims the benefit of U.S. Provisional Application Ser. No. 62/968,074, filed Jan. 30, 2020, the content of which is hereby incorporated by reference in its entirety.

The invention relates to devices, systems, and methods for performing downhole operations, and in particular to devices configured to determine its downhole location in a wellbore and, based on the determination, self-activate to effect a downhole operation, and systems and methods related thereto.

Recently wellbore treatment apparatus have been developed that include a wellbore treatment string for staged well treatment. The wellbore treatment string is useful to create a plurality of isolated zones within a well and includes an openable port system that allows selected access to each such isolated zone. The treatment string includes a tubular string carrying a plurality of external annular packers that can be set in the hole to create isolated zones therebetween in the annulus between the tubing string and the wellbore wall, be it cased or open hole. Openable ports, passing through the tubing string wall, are positioned between the packers and provide communication between the tubing string inner bore and the isolated zones. The ports are selectively openable and include a sleeve thereover with a sealable seat formed in the inner diameter of the sleeve. By launching a plug, such as a ball, a dart, etc., the plug can seal against the seat of a port's sleeve and pressure can be increased behind the plug to drive the sleeve through the tubing string to open the port and gain access to an isolated zone. The seat in each sleeve can be formed to accept a plug of a selected diameter but to allow plugs of smaller diameters to pass. As such, a port can be selectively opened by launching a particular sized plug, which is selected to seal against the seat of that port.

Unfortunately, however, such a wellbore treatment system tends to be limited in the number of zones that may be accessed. In particular, limitations with respect to the inner diameter of wellbore tubulars, often due to the inner diameter of the well itself, restrict the number of different sized seats that can be installed in any one string. For example, if the well diameter dictates that the largest sleeve seat in a well can at most accept a 3¾″ plug, then the well treatment string will generally be limited to approximately eleven sleeves and, therefore, treatment can only be effected in eleven stages. Therefore, it is desirable to have a wellbore treatment system that allows the same size sleeve seats to be used throughout the tubing string so that the wellbore treatment system can have more stages. Also, if the sleeve seats in the tubing string are identical to one another, the sleeve seats do not have to be installed in any particular order.

In some situations, the plug is configured to seal the wellbore during a well completion operation, such as fracking in the zone through the open port. Rubber and other elastomeric materials are commonly used as seals in settable plugs. A general problem in the art is the undesired deformation of the seal during setting, and also subsequent deformation, both due to extrusion of the seal material. Under axial compression, extrusion can occur in conventional seal rings through any gaps in or around the compression ring of the compression setting mechanism. Such extrusion can cause the seal to deform, crack up, or erode, thereby compromising the seal's integrity which may lead to unwanted leakages.

The present disclosure thus aims to address the above-mentioned issues.

According to a broad aspect of the present disclosure, there is provided 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.

In some embodiments, 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 analyzing comprises determining whether the change in the z-axis signal is greater than or equal to a predetermined threshold magnitude.

In some embodiments, 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.

In some embodiments, 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.

In some embodiments, 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.

In some embodiments, the method comprises adjusting a baseline of the y-axis signal based at least in part on the x-axis signal.

In some embodiments, the first magnet and the second magnet are rare-earth magnets.

In some embodiments, 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 the at least one feature comprises a constriction.

In some embodiments, 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.

In some embodiments, 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:

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 the change comprises a change in the ambient magnetic field.

In some embodiments, analyzing comprises determining whether the change falls within a parameters profile of one of the at least one feature.

In some embodiments, the parameters profile comprises a minimum magnetic field threshold, and 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.

In some embodiments, the parameters profile comprises a maximum magnetic field threshold, and 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.

In some embodiments, the parameters profile comprises a minimum timespan and a maximum timespan, and determining whether the change falls within the parameters profile comprises determining whether the elapsed time is between the minimum timespan and the maximum timespan.

In some embodiments, the change is caused by the proximity of the at least one feature to the third magnet, and monitoring comprises calculating a magnetic field M of the third magnet using:

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 the change comprises a change in the magnetic field of the third magnet.

In some embodiments, analyzing comprises determining whether the change falls within a parameters profile of one of the at least one feature.

In some embodiments, the parameters profile comprises a minimum magnetic field threshold, and 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.

In some embodiments, the parameters profile comprises a maximum magnetic field threshold, and 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.

In some embodiments, the parameters profile comprises a minimum timespan and a maximum timespan, and determining whether the change falls within the parameters profile comprises determining whether the elapsed time is between the minimum timespan and the maximum timespan.

In some embodiments, each of the at least one feature is a magnetic feature or a thicker feature.

In some embodiments, 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.

In some embodiments, the method comprises, 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.

In some embodiments, the method comprises, 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.

In some embodiments, activating the device comprises actuating an engagement mechanism of the device.

In some embodiments, the method comprises 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.

In some embodiments, determining the distance is based at least in part on a rotation of the device measured by a gyroscope in the device.

According to another broad aspect of the present disclosure, there is provided 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.

In some embodiments, 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.

In some embodiments, the second long side length is equal to or greater than the first long side length.

In some embodiments, second short side length is equal to or greater than the first short side length.

In some embodiments, the second long side length is less than the first long side length.

In some embodiments, second short side length is less than the first short side length.

In some embodiments, the first gap is positioned at or near the first short side.

In some embodiments, the second gap is positioned at or near the second short side.

In some embodiments, 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.

In some embodiments, the first gap is azimuthally offset from the second gap.

In some embodiments, one or both of the first and second faces are circular.

In some embodiments, the first elliptical face is inclined at an angle ranging from about 1° to about 30° relative to the first face.

In some embodiments, 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.

In some embodiments, 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.