Automated formation fluid clean-up to sampling switchover
Apparatus and method for downhole formation fluid sampling include conveying a carrier into a well borehole that traverses a subterranean formation of interest, the carrier having a port and placing the port in fluid communication with the subterranean formation of interest. The method includes urging a fluid into the port using a fluid control device, the fluid containing a formation fluid and a contaminant, generating a first signal indicative of a first fluid characteristic of the fluid using a first test device in communication with the fluid, and generating a second signal indicative of a second fluid characteristic of the fluid using a second test device in communication with the fluid. The first signal and the second signal are processed using a processing device to estimate a level of contamination in the fluid, and a control signal is generated when the estimated level of contamination meets a predetermined value, the control signal actuating the fluid control device to direct fluid having a level of contamination at about or below the predetermined value to a fluid sampling chamber carried by the carrier.
1. A downhole apparatus comprising:
a carrier conveyable in a well borehole;
a pump providing a variable pump rate for generating a pressure gradient across a flow path of a fluid;
a fluid control device that urges the fluid into a port, the fluid containing a contaminant;
a first test device in communication with the fluid, the first test device generating a first signal indicative of a first fluid characteristic;
a second test device in communication with the fluid, the second test device generating a second signal indicative of a second fluid characteristic; and
a processing device that receives the first signal and the second signal, the processing device processing the first signal and the second signal to estimate a level of contamination in the fluid, the processing device generating a control signal when the estimated level of contamination meets a predetermined value.
2. A method for estimating fluid contamination downhole comprising:
conveying a carrier in a well borehole;
adjusting a variable pump rate to reduce a contaminant disposed in a fluid;
urging the fluid into a port using a fluid control device, the fluid containing a contaminant;
generating a first signal indicative of a first fluid characteristic using a first test device in communication with the fluid;
generating a second signal indicative of a second fluid characteristic using a second test device in communication with the fluid;
processing the first signal and the second signal using a processing device to estimate a level of contamination in the fluid; and
generating a control signal when the estimated level of contamination meets a predetermined value.
3. A downhole apparatus comprising:
a carrier conveyable in a well borehole;
a pump providing a variable pump rate for generating a pressure gradient across a flow path of a fluid;
a fluid control device that urges the fluid into a port, the fluid containing a contaminant;
a test device in communication with the fluid, the test device generating a signal indicative of a fluid characteristic;
a processing device that receives the signal, the processing device processing the signal to estimate a level of contamination in the fluid, the processing device generating a control signal when the estimated level of contamination meets a predetermined value.
4. An apparatus according to claim 3 , wherein the test device includes a device for estimating an optical characteristic of the fluid.
5. An apparatus according to claim 3 , wherein the test device comprises one or more of a fluorescence test device, a reflectometer and a spectrometer.
6. An apparatus according to claim 3 , wherein the test device includes a device for estimating an electrical characteristic of the fluid.
7. An apparatus according to claim 6 , wherein the device for estimating an electrical characteristic comprises one or more of a resistivity test device, a capacitance test device, and a dielectric test device.
8. An apparatus according to claim 3 , wherein the test device includes a device for estimating a physical characteristic of the fluid.
9. An apparatus according to claim 3 , wherein the test device comprises one or more of a viscometer, a pressure transducer, a temperature transducer, a fluid density test device, and a sonic test device.
10. An apparatus according to claim 3 , wherein the test device comprises one or more of a chemical test device, a fluid compositional analysis device, a gas chromatograph, a pH test device, a salinity test device, a CO 2 test device, an H 2 S test device, a device for determining wax and asphaltene components, a device for determining metal content, and a device for determining acidity of the fluid.
11. An apparatus according to claim 3 , wherein the test device includes a plurality of devices for estimating a combination of at least two of an optical characteristic, an electrical characteristic, a physical characteristic and a chemical characteristic of the fluid.
12. An apparatus according to claim 3 , wherein the fluid control device includes one or more addressable pumps that receive control instructions from the processing device.
13. An apparatus according to claim 3 , wherein the fluid control device includes one or more addressable valves that receive control instructions from the processing device.
14. An apparatus according to claim 3 , wherein the apparatus comprises a fluid sampling device.
15. An apparatus according to claim 3 , wherein the control signal actuates the fluid control device to direct fluid having a level of contamination at about or below the predetermined value to a fluid sampling chamber carried by the carrier.
16. An apparatus according to claim 3 further comprising at least another pump.
17. An apparatus according to claim 3 , wherein the pump rate is adjusted for a clean-up process.
18. An apparatus according to claim 3 , wherein the pump generates a flow in a sleeve surrounding a cavity.
19. An apparatus according to claim 3 , wherein the pressure gradient comprises a vector of a varying direction and a varying magnitude.
20. A method for estimating fluid contamination downhole comprising:
conveying a carrier in a well borehole;
adjusting a variable pump rate to reduce a contaminant disposed in a fluid;
urging the fluid into a port using a fluid control device, the fluid containing a contaminant;
generating a signal indicative of a fluid characteristic using a test device in communication with the fluid;
processing the signal using a processing device to estimate a level of contamination in the fluid; and
generating a control signal when the estimated level of contamination meets a predetermined value.
21. A method according to claim 20 , wherein the signal is indicative of an optical characteristic of the fluid.
22. A method according to claim 21 , wherein the optical characteristic comprises one or more of fluorescence, a reflectance and spectral energy.
23. A method according to claim 20 , wherein the signal is indicative of an electrical characteristic of the fluid.
24. A method according to claim 23 , wherein the electrical characteristic comprises one or more of resistivity, capacitance, and dielectric constant.
25. A method according to claim 20 , wherein the signal is indicative of a physical characteristic of the fluid.
26. A method according to claim 25 , wherein the physical characteristic comprises one or more of viscosity, pressure, temperature, fluid density, and acoustic transmittance.
27. A method according to claim 20 , wherein generating the signal includes generating one or more signals indicative of a combination of at least two of an optical characteristic, an electrical characteristic, a chemical characteristic and a physical characteristic of the fluid.
28. A method according to claim 20 , wherein the fluid control device includes one or more addressable pumps, the method including sending control instructions from the processing device to the one or more addressable pumps.
29. A method according to claim 20 , wherein the fluid control device includes one or more addressable valves, the method including sending control instructions from the processing device to the one or more addressable valves.
30. A method according to claim 20 further comprising sampling the fluid using a fluid sampling device.
31. A method according to claim 20 further comprising actuating the fluid control device using the control signal; and using the fluid control device to direct fluid having a level of contamination at about or below the predetermined value to a fluid sampling chamber carried by the carrier.
32. A method according to claim 20 , wherein adjusting comprises generating a pressure gradient across a flow path of the fluid.