Permittivity measurements with oil-based mud imaging tool
AssigneeHalliburton Energy Services, Inc.
InventorsLuis E. San Martin, William J. Schaecher, Myrick L. Monroe
Life of this patent
Estimating the term…
Abstract
Oil-based mud imaging systems and methods that measure formation permittivity. In some embodiments, disclosed logging systems include a logging tool in communication with surface computing facilities. The logging tool is provided with a sensor array having at least two voltage electrodes positioned between at least two current electrodes that create an electric field in a borehole wall, and is further provided with electronics coupled to the voltage electrodes to determine a differential voltage magnitude and phase. From the magnitude and phase, formation resistivity and permittivity measurements can be determined and used to construct a borehole wall image.
Claims15
A logging method that comprises:
- creating an oscillatory electric field in a wall of a borehole using at least two current electrodes of a sensor array, wherein the borehole is filled with a nonconductive fluid;
- measuring a differential voltage phase and magnitude with at least two voltage electrodes positioned between the at least two current electrodes;
- using the differential voltage phase and magnitude and a current flow magnitude to determine a permittivity measurement that is associated with a position on the borehole wall;
- and
- forming a borehole wall image from multiple such permittivity measurements.
A logging tool that comprises:
- a sensor array having at least two voltage electrodes positioned between at least two current electrodes, wherein the at least two current electrodes are energized to create an oscillatory electric field in a formation forming a wall of a borehole enclosing a nonconductive borehole fluid;
- a voltage detector coupled to the at least two voltage electrodes to measure a differential voltage phase and magnitude induced by the electric field;
- and
- a processor in communication with the voltage detector and at least one current sensor to determine a measurement indicative of formation permittivity based at least in part on the differential voltage phase and magnitude;
- wherein multiple such measurements indicative of formation permittivity are associated with positions on the borehole wall and are combined to form a borehole wall image.
Dependencies are inferred from the claim text.