Geologic formation characterization via fluid separation

1. A method comprising:

flowing fluid from a formation from an inlet of a tool to an annulus;

flowing spacer fluid from a conduit to the annulus by flowing a first portion of the spacer fluid to form a first spacer and flowing a second portion of the spacer fluid to form a second spacer;

flowing the fluid and the spacer fluid in the annulus to a station by flowing the fluid between the first spacer and the second spacer; and

collecting the fluid.

2. The method of claim 1 , wherein the spacer fluid is formulated to reduce miscibility with hydrocarbon content of the fluid from the formation.

3. The method of claim 1 , wherein flowing the fluid and the spacer fluid in the annulus to the station comprises utilizing a bypass line that bypasses a portion of the annulus that extends to a rig platform.

4. The method of claim 3 , wherein the bypass line is in fluid communication with a blowout preventer.

5. The method of claim 1 , comprising suspending the tool via a cable.

6. The method of claim 1 , comprising deploying the tool via a string of drillpipe, wherein the tool is operatively coupled to a cable that runs along the string of drillpipe, wherein the cable comprises at least one power conductor and at least one data conductor.

7. The method of claim 1 , comprising deploying the tool via coiled tubing, wherein the tool is operatively coupled to a cable that runs along the coiled tubing, wherein the cable comprises at least one power conductor and at least one data conductor.

8. The method of claim 1 , comprising deploying at least one packer that is operatively coupled to the tool.

9. The method of claim 1 , comprising operating at least one pump that is operatively coupled to the tool.

10. The method of claim 1 , comprising separating gas from the fluid at the station.

11. The method of claim 1 , comprising measuring a property of the fluid using a sensor of the tool.

12. The method of claim 1 , comprising measuring a property of the fluid using a sensor of the station.

13. The method of claim 1 , wherein flowing fluid from the formation from the inlet of the tool to the annulus comprises flowing a volume of the fluid into the spacer fluid to divide the spacer fluid into at least two portions that form at least two corresponding spacers.

14. The method of claim 1 , comprising measuring a property of the fluid using a sensor of the tool and, based at least in part on the property, determining a characteristic of the spacer fluid.

15. The method of claim 14 , wherein the property comprises a gas property.

16. The method of claim 14 , wherein the characteristic of the spacer fluid reduces risk of a kick.

17. The method of claim 1 , comprising measuring a property of the fluid using the tool and, based at least in part on the property, determining an amount of the fluid to flow to the annulus.

18. A system comprising:

a tool operatively coupled to a cable that comprises a packer, a fluid inlet, a fluid outlet, a pump, at least one power conductor and at least one data conductor;

a blowout preventer that comprises a bypass line coupling in fluid communication with an annulus;

a bypass line attached to the bypass line coupling and in fluid communication with the annulus and a station;

a spacer fluid pump in fluid communication with a conduit, wherein an opening of the conduit is in fluid communication with an opening of the annulus; and

a system controller that comprises processor-executable instructions executable by a processor to:

instruct the spacer fluid pump to pump spacer fluid to the conduit,

instruct the tool to flow formation fluid, wherein at least a portion of the spacer fluid and at least a portion of the formation fluid flow sequentially to the annulus, from the annulus to the bypass line and from the bypass line to the station, and

instruct the station to collect a volume of the formation fluid.

19. One or more computer-readable storage media comprising processor-executable instructions, executable to instruct a system to:

flow fluid from a formation from an inlet of a tool to an annulus;

flow a first portion of a spacer fluid from a conduit to the annulus;

flow a second portion of the spacer fluid from the conduit to the annulus;

flow the fluid between the first and second portions of the spacer fluid in the annulus to a station; and

collect the fluid.

20. A method comprising:

flowing a spacer fluid from a conduit to an annulus;

flowing a formation fluid from an inlet of a tool into the spacer fluid in the annulus and dividing the spacer fluid into at least two portions that form at least two corresponding spacers;

flowing the formation fluid and the spacer fluid portions in the annulus to a station; and

collecting the formation fluid.