Rare earth alloys as borehole markers
AssigneeHalliburton Energy Services, Inc.
InventorsJoe Eli Hess, Andrew Cuthbert
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Abstract
A magnetic marking method includes drilling a borehole and marking a position along an uncased section of the borehole with a magnetic marker comprising a magnetic rare earth alloy. A magnetic marker for open hole use includes an unconsolidated mass of high remanence, magnetized material that comprises a magnetic rare earth alloy. The magnetic marker for open hole use also includes a suspension fluid suited for conveying the magnetized material through a drill string bore into an open borehole. A magnetic marker for a casing terminus includes a magnet comprising a magnetic rare earth alloy and an attachment mechanism that secures the magnet to a casing shoe. Such magnetic markers for open hole use or a casing terminus can be used for borehole intersection operations.
Claims23
A magnetic marking method that comprises:
- drilling a borehole;
- and
- marking a position at a borehole terminus of the borehole with an unconsolidated marker mass comprising a magnetic rare earth alloy,
- wherein said marking comprises conveying the unconsolidated marker mass to the position at the borehole terminus using a flow stream and wherein the position is within an uncased section of the borehole.
A borehole intersection method that comprises:
- obtaining target borehole parameters for a target borehole including at least one passive magnetic marker's estimated position along the target borehole, said at least one passive magnetic marker comprising an unconsolidated maker mass comprising a magnetic rare earth alloy and positioned at a borehole terminus of the target borehole;
- and
- drilling a relief borehole to intersect the target borehole at an intersection point selected relative to the at least one magnetic marker's estimated position, where said drilling includes:
- sensing a magnetic field from the at least one magnetic marker;
- and
- based at least in part on the magnetic field, directing a steerable drilling assembly toward the intersection point along an uncased portion of the target borehole.
A system for marking positions within a borehole, the system comprising:
- one or more passive magnetic markers deployed in a borehole to mark one or more positions within the borehole, wherein at least one of the one or more passive magnetic markers comprises a magnet comprising a magnetic rare earth alloy located at casing terminus of a cased portion of the borehole;
- a casing shoe comprising at least one of the one or more passive magnetic markers and positioned to identify a casing terminus of the cased portion of borehole, wherein the at least one of the passive magnetic markers comprises a magnet comprising a magnetic rare earth alloy;
- and
- an unconsolidated marker mass positioned to identify a borehole terminus of the borehole, wherein the unconsolidated mass comprises a magnetic rare earth alloy.
A passive magnetic marker for open hole use in a borehole, the passive magnetic marker comprising:
- an unconsolidated mass of high remanence, magnetized material that comprises a magnetic rare earth alloy;
- and
- a suspension fluid suited for conveying the magnetized material through a drill string bore into the open borehole for marking a position at a borehole terminus of an uncased section of the borehole.
Dependencies are inferred from the claim text.