Apparatus and methods for making azimuthal resistivity measurements
AssigneeWell Resolutions Technology
InventorTsili WANG
Life of this patent
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Abstract
A resistivity measuring tool used in a drillstring having a drill bit on a distal end for drilling a wellbore in a formation includes a tool body having a longitudinal axis, a sensor configured to measure the angular position of the tool body relative to the wellbore, at least one axial antenna including a wire winding for generating an axial magnetic moment parallel with the longitudinal axis, and at least one transverse antenna. The transverse antenna includes an antenna body disposed within a pocket extending radially inward from an outer surface of the tool body and one or more turns of wire wound around the antenna body, the wire winding generating a transverse magnetic moment orthogonal to the longitudinal axis.
Claims20
A resistivity measuring tool used in a drillstring having a drill bit on a distal end for drilling a wellbore in a formation, the tool comprising:
- a tool body having a longitudinal axis;
- a sensor configured to measure the angular position of the tool body relative to the wellbore;
- at least one axial antenna including a wire winding for generating an axial magnetic moment parallel with the longitudinal axis;
- and
- at least one transverse antenna comprising:
- an antenna body disposed within a pocket extending radially inward from an outer surface of the tool body;
- and
- one or more turns of wire wound around the antenna body, the wire winding generating a transverse magnetic moment orthogonal to the longitudinal axis,
- wherein at least one antenna is configured to transmit electromagnetic energy into the formation and induce a voltage signal related to a parameter of the formation in a different antenna.
A method of making resistivity measurements of a formation from a wellbore being drilled, the method comprising:
- providing a resistivity measuring tool comprising:
- a tool body having a sensor configured to measure the angular position of the tool body relative to the wellbore,
- at least one axial antenna including a wire winding for generating an axial magnetic moment, and
- at least one transverse antenna disposed proximate to an outer surface of the tool body and including a wire winding for generating a transverse magnetic moment;
- transmitting electromagnetic energy into the formation from at least one of the antennas, thereby inducing a voltage signal related to a formation parameter in the wire winding of a non-transmitting antenna;
- measuring an angular position of the tool body relative to the wellbore with the sensor;
- and
- correlating the formation parameter with the measured angular position of the tool body.
A method of making resistivity measurements of a formation from a wellbore being drilled, the method comprising:
- providing a resistivity measuring tool comprising:
- a tool body having a sensor configured to measure the angular position of the tool body relative to the wellbore;
- at least two axial antennas each including a wire winding for generating an axial magnetic moment;
- and
- a transverse antenna disposed between the two axial antennas and including a wire winding for generating a transverse magnetic moment;
- substantially simultaneously driving a current to the wire windings of the two axial antennas for generating a current loop in the formation, thereby inducing a voltage signal related to a formation parameter in the wire winding of the transverse antenna disposed therebetween;
- measuring an angular position of the tool body relative to the wellbore with the sensor;
- and
- correlating the formation parameter with the measured angular position of the tool body.
A method of data binning comprising:
- partitioning a circumference of a tool face into M number of sectors;
- defining each data point relating to resistivity information by a fidelity function g(Φ);
- assigning to each data point a weight for each of the M number of sectors, wherein the weight is associated with an integral of the fidelity function g(Φ) over the sector;
- and
- computing an average of the data points weighted by their respective weights for each of the M sectors.
Dependencies are inferred from the claim text.