Devices, systems, and methods for selectively engaging downhole tool for wellbore operations
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.
1. A method comprising:
deploying a device into a passageway of a tubing string; and
while the device is deployed within the passageway:
measuring, by a magnetometer in the device, one or more of: a z-axis magnetic field in a z-axis, an x-axis magnetic field in a x-axis, and a y-axis magnetic field in a y-axis, wherein the z-axis is parallel to a direction of travel of the device, and the x-axis and y-axis are orthogonal to the z-axis and to each other;
generating at least a z-axis signal based on the z-axis magnetic field; and
monitoring at least the z-axis signal to detect a change; and
analyzing the change to detect at least one feature in the tubing string,
wherein:
the change is caused by a movement of a first magnet in the device relative to a second magnet in the device;
the change comprises a change in the z-axis signal; and
the analyzing comprises determining whether the change in the z-axis signal is greater than or equal to a predetermined threshold magnitude.
2. The method of claim 1 , further comprising:
generating an x-axis signal based on the x-axis magnetic field and a y-axis signal based on the y-axis magnetic field; and
wherein the 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.
3. The method of claim 2 wherein: the 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.
4. The method of claim 1 , further comprising:
generating an x-axis signal based on the x-axis magnetic field and a y-axis signal based on the y-axis magnetic field; and
wherein the 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 1 , comprising:
generating an x-axis signal based on the x-axis magnetic field and a y-axis signal based on the y-axis magnetic field; and
adjusting a baseline of the y-axis signal based at least in part on the x-axis signal.
6. The method of claim 1 , wherein the first magnet and the second magnet are rare-earth magnets.
7. The method of claim 1 , 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.
8. The method of claim 7 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.