Fluid holdup monitoring in downhole fluid sampling tools

1. A method to identify fluid holdups during downhole fluid sampling operations, the method comprising:

obtaining, using a sampling tool positioned within a wellbore, one or more fluid measurements using at least one sensor having a first set of spatial resolution, wherein the at least one sensor is selected from the group of sensors consisting of an optical spectroscopy, index of refraction, fluorescence, a laser, and any combination thereof;

obtaining, using the sampling tool, one or more fluid measurements using at least one sensor having a second set of spatial resolution, wherein the at least one sensor is selected from the group of sensors consisting of a density, capacitance, dielectric spectroscopy, viscosity sensor, and any combination thereof, wherein the second set of spatial resolution is lower than the first set of spatial resolution;

calculating a first fluid ratio comprising a water ratio, an oil ratio, or a gas ratio using the at least one sensor having the first set of spatial resolution;

calculating a second fluid ratio using the at least one sensor having the second set of spatial resolution; and

identifying fluid holdup within the sampling tool when the differences between the two fluid ratios are higher than a limit or a similarity of the two fluid ratios are lower than a limit.

2. The method as defined in claim 1 , wherein the first and second ratios are mud ratios of the first and second fluid measurements.

3. The method as defined in claim 1 , wherein the first and second ratios are formation fluid ratios of the first and second fluid measurements.

4. The method as defined in claim 1 , further comprising flushing the fluid holdups out of the sampling tool.

5. A system to identify fluid holdups during downhole fluid sampling operations, the system comprising:

a fluid sampling tool comprising:

a first spatial resolution sensor, wherein the first spatial resolution sensor is an optical, infrared or laser sensor; and

a second spatial resolution sensor having a spatial resolution lower than the first spatial resolution sensor, wherein the second spatial resolution sensor is a density, dielectric, viscosity, or capacitance sensor; and

processing circuitry to perform operations comprising:

obtaining, using the first spatial resolution sensor, one or more fluid measurements;

obtaining, using the second spatial resolution sensor, one or more fluid measurements;

calculating a first fluid ratio comprising a water ratio, an oil ratio, or a gas ratio using the first spatial resolution sensor;

calculating a second fluid ratio using the second spatial resolution sensor; and

identifying fluid holdup within the fluid sampling tool when the differences between the two fluid ratios are higher than a limit or a similarity of the two fluid ratios are lower than a limit.

6. The system as defined in claim 5 , wherein the first and second ratios are mud ratios of the first and second fluid measurements.

7. The system as defined in claim 5 , wherein the first and second ratios are formation fluid ratios of the first and second fluid measurements.

8. The system as defined in claim 5 , further comprising flushing the fluid holdups out of the sampling tool.

9. A non-transitory computer program product including instruction which, when executed by at least one processor, causes the processor to a method comprising:

obtaining, using a sampling tool positioned within a wellbore, one or more fluid measurements using an optical spectroscopy, index of refraction, fluorescence, or a laser sensor;

obtaining, using the sampling tool, one or more fluid measurements using a density, capacitance, dielectric spectroscopy, or viscosity sensor, wherein the optical spectroscopy, index of refraction, fluorescence, or laser sensor has a higher spatial resolution than the density, capacitance, dielectric spectroscopy, or viscosity sensor;

calculating a first fluid ratio comprising a water ratio, an oil ratio, or a gas ratio using the optical spectroscopy, index of refraction, fluorescence, or laser sensor;

calculating a second fluid ratio using the density, capacitance, dielectric spectroscopy, or viscosity sensor; and

identifying fluid holdup within the sampling tool when the differences between the two fluid ratios are higher than a limit or a similarity of the two fluid ratios are lower than a limit.

10. The computer program product as defined in claim 9 , wherein the first and second ratios are mud ratios of the first and second fluid measurements.

11. The computer program product as defined in claim 9 , wherein the first and second ratios are formation fluid ratios of the first and second fluid measurements.

12. The computer program as defined in claim 9 , further comprising flushing the fluid holdups out of the sampling tool.