Abstract: A high-pressure capable sealing apparatus and method for sealing against an interior surface of a cylindrical tubular member provides the ability to expand to a larger diameter from a given running diameter and to transition back to the original diameter. The sealing apparatus may include a ring assembly with a metallic ring characterized by a uniform axial cross-sectional profile having an outward-facing convexity and an inward-facing concavity. A plurality of slits may be radially formed through the ring about the outer surface to relieve stress within the ring during radial expansion. A circular resilient gasket may be at least partially coaxially disposed within the ring concavity. The ring assembly may be located between uphole and downhole shoulders, which may be selectively axially movable with respect to one another so as to selectively axially compress and radially expand the ring into sealing engagement with a tubular member.

Abstract: A method of removing a wellbore isolation device comprising: causing or allowing at least a portion of the isolation device to undergo a phase transformation in the wellbore; and milling at least a portion of the isolation device that does not undergo the phase transformation.

Abstract: A well tool can include a magnetic sensor having opposite sides, and a magnetic shield that conducts an undesired magnetic field from one side to the other side of the sensor. Another well tool can include a magnetic sensor in a housing, the sensor having opposite longitudinal sides relative to a housing longitudinal axis, and a magnetic shield interposed between the housing and each of the opposite longitudinal sides of the magnetic sensor. Another well tool can include at least two magnetic sensors, one magnetic sensor sensing a magnetic field oriented orthogonal to the housing longitudinal axis, and another magnetic sensor sensing a magnetic field oriented parallel to the longitudinal axis, and a magnetic shield interposed between a housing and each of opposite longitudinal sides of the magnetic sensors.

Abstract: A high-pressure capable sealing apparatus and method for sealing against an interior surface of a cylindrical tubular member provides the ability to expand to a larger diameter from a given running diameter and to transition back to the original diameter. The sealing apparatus may include a ring assembly with a metallic ring characterized by a uniform axial cross-sectional profile having an outward-facing convexity and an inward-facing concavity. A plurality of slits may be radially formed through the ring about the outer surface to relieve stress within the ring during radial expansion. A circular resilient gasket may be at least partially coaxially disposed within the ring concavity. The ring assembly may be located between uphole and downhole shoulders, which may be selectively axially movable with respect to one another so as to selectively axially compress and radially expand the ring into sealing engagement with a tubular member.

Abstract: A method of removing a wellbore isolation device comprising: causing or allowing at least a portion of the isolation device to undergo a phase transformation in the wellbore; and milling at least a portion of the isolation device that does not undergo the phase transformation.

Abstract: A system for use with a subterranean well can include a magnetic sensor, a magnetic device which propagates a magnetic field to the magnetic sensor, and a barrier positioned between the magnetic sensor and the magnetic device. The barrier can comprise a relatively low magnetic permeability material. A method of isolating a magnetic sensor from a magnetic device in a subterranean well can include separating the magnetic sensor from the magnetic device with a barrier interposed between the magnetic sensor and the magnetic device, the barrier comprising a relatively low magnetic permeability material. A well tool can include a housing having a flow passage formed through the housing, a magnetic sensor in the housing, and a barrier which separates the magnetic sensor from the flow passage, the barrier having a lower magnetic permeability as compared to the housing.

Abstract: A well tool can include a magnetic sensor having opposite sides, and a magnetic shield that conducts an undesired magnetic field from one side to the other side of the sensor. Another well tool can include a magnetic sensor in a housing, the sensor having opposite longitudinal sides relative to a housing longitudinal axis, and a magnetic shield interposed between the housing and each of the opposite longitudinal sides of the magnetic sensor. Another well tool can include at least two magnetic sensors, one magnetic sensor sensing a magnetic field oriented orthogonal to the housing longitudinal axis, and another magnetic sensor sensing a magnetic field oriented parallel to the longitudinal axis, and a magnetic shield interposed between a housing and each of opposite longitudinal sides of the magnetic sensors.

Abstract: A system for use with a subterranean well can include a magnetic sensor, a magnetic device which propagates a magnetic field to the magnetic sensor, and a barrier positioned between the magnetic sensor and the magnetic device. The barrier can comprise a relatively low magnetic permeability material. A method of isolating a magnetic sensor from a magnetic device in a subterranean well can include separating the magnetic sensor from the magnetic device with a barrier interposed between the magnetic sensor and the magnetic device, the barrier comprising a relatively low magnetic permeability material. A well tool can include a housing having a flow passage formed through the housing, a magnetic sensor in the housing, and a barrier which separates the magnetic sensor from the flow passage, the barrier having a lower magnetic permeability as compared to the housing.