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US 2006/0132129 A1Published application
Azimuthal NMR imaging while drilling
AssigneeBaker Hughes Incorporated
InventorCarl Edwards
Life of this patent
Estimating the term…
Abstract
NMR measurements are made with a MWD tool having azimuthal sensitivity. The permanent magnet may be a U-shaped magnet or may have an opposed pair of magnets with axial orientation. The tool is designed for pulsing with short sequences for estimating BVI and CBW and minimizes the effect of tool motion.
Claims30
An apparatus for evaluating an earth formation comprising:
- (a) a bottomhole assembly (BHA) conveyed in a borehole in the earth formation, the BHA having a longitudinal axis;
- and
- (b) at least one sensor assembly carried by the BHA, the at least one sensor assembly including
- (A) a U-shaped magnet which provides a static magnetic field in a sensitive region in said formation, and
- (B) an antenna arrangement which produces a pulsed radio frequency (RF) magnetic field in the sensitive region and receives signals from nuclei in the sensitive region.
2 more elements
An apparatus for evaluating an earth formation, the apparatus comprising:
- (a) a bottomhole assembly (BHA) conveyed in a borehole in the earth formation, the BHA having a longitudinal axis;
- and
- (b) a sensor assembly carried by the BHA, the sensor assembly including
- (A) a magnet configuration which provides a static magnetic field in a sensitive region in the formation,
- (B) a transmitter coil having an axis parallel to the longitudinal axis which produces a pulsed radio frequency (RF) magnetic field in the sensitive region, and
- (C) at least one receiver coil which receives signals from nuclei in the sensitive region, the at least one receiver coil having an axis substantially orthogonal to an axis of the transmitter coil.
3 more elements
A method of evaluating an earth formation comprising:
- (a) conveying a bottomhole assembly (BHA) conveyed in a borehole in the earth formation, the BHA having a longitudinal axis;
- and
- (b) using a U-shaped magnet forming part of at least one sensor assembly carried by the BHA and producing a static magnetic field in a sensitive region in said formation, the static magnetic field in the sensitive region having an azimuthal direction,
- (c) producing a pulsed radio frequency (RF) magnetic field in the sensitive region, the RF field having a radial direction in the sensitive region, and
- (d) receiving signals from nuclei in the sensitive region,
2 more elements
A method of evaluating an earth formation, the method comprising:
- (a) conveying a bottomhole assembly (BHA) conveyed in a borehole in the earth formation, the BHA having a longitudinal axis;
- and
- (b) using a magnet configuration and producing a static magnetic field in a sensitive region in the formation, the static magnetic field having a radial direction in the sensitive region,
- (c) producing a pulsed radio frequency (RF) magnetic field in the sensitive region, and
- (d) receiving signals from nuclei in the sensitive region using at least one receiver coil having an axis substantially orthogonal to the longitudinal axis.
2 more elements
Dependencies are inferred from the claim text.