Magnetic Force Reducer
AssigneeBaker Hughes Incorporated
InventorsHomero C. Castillo, Otto N. Fanini
Life of this patent
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Abstract
A downhole tool includes a housing, a permanent magnet in the housing, and magnetic field source that selectively generates a magnetic field which counters a magnetic field generated by the permanent magnet. The downhole tool is deployed in a wellbore that intersects a subterranean formation, and is used for imaging the formation. The magnetic field source can be a coil through which an electrical current is selectively conducted. The electrical current can be continuously applied or pulsed through the coil.
Claims18
A method of operations in a wellbore comprising:
- providing a downhole tool that comprises a housing and a permanent magnet;
- deploying the downhole tool in the wellbore and within a tubular inserted in the wellbore so that a first magnetic field formed by the permanent magnet generates a force that attracts the downhole tool and the tubular inner surface;
- and
- selectively countering the first magnetic field with a second magnetic field to reduce the force that attracts the housing with the tubular inner surface.
A method of operations in a wellbore comprising:
- operating, inside of the wellborn, a downhole tool that comprises a housing and a source of a first magnetic field within the housing;
- moving the downhole tool within tubing that is inserted in the wellbore, so that the first magnetic field generates an attractive force between the downhole tool and an inner surface of the tubular;
- and
- selectively forming a second magnetic field which counters the attractive force between die downhole tool and inner surface of the tubular.
The method of claim 10, wherein the second magnetic field is formed by flowing electrical current along a helical path. cm 13. The method of claim 12, wherein the electrical current applied is constant, or has a time varying waveform, amplitude and frequency.
A downhole tool for use in a wellbore comprising:
- a housing;
- a permanent magnet that forms a first magnetic field;
- and
- an electromagnetic field source that selectively forms a second magnetic field which counters the first magnetic field.
Dependencies are inferred from the claim text.