Device for determining a volume of liquid in a fluid sample

1. A device for determining a volume of liquid in a hydrocarbon fluid sample, the device including:

a cell comprising an upper part defined by a tubular sidewall and a lower part defined by a cone-shaped closed extremity, the lower part forming a chamber configured to receive the liquid; and

a piston comprising an upper part, a lower part, and a window oriented towards the cone-shaped closed extremity of the cell, the piston being slideable in the cell and sealing the cell in a gas-tight manner.

2. The device according to claim 1 , wherein the closed extremity of the cell has an aperture from 30° to 120°.

3. The device according to claim 1 , wherein the lower part of the cell comprises at least one marking on a peripheral surface of the cone-shaped closed extremity.

4. The device according to claim 3 , wherein each marking is in a form of a circular arc.

5. The device according to claim 3 , wherein the at least one markings is arranged in one or several conical sectors on the peripheral surface of the cone-shaped closed extremity.

6. The device according to claim 5 , wherein the at least one marking is arranged in two conical sectors on the peripheral surface of the cone-shaped closed extremity.

7. The device according to claim 1 , wherein the lower part of the piston has a truncated-cone shape in order to be partly slideable within the lower part of the cell.

8. The device according to claim 1 , wherein the piston comprises an endoscope configured to connect the window with a monitoring system.

9. The device according to claim 1 , wherein a system for illuminating the cell is arranged in the piston.

10. The device according to claim 1 , wherein the upper part of the cell comprises at least one fluid inlet and at least one fluid outlet.

11. An assembly comprising:

(a) a device for determining a volume of liquid in a hydrocarbon fluid sample, the device including:

a cell comprising an upper part defined by a tubular sidewall and a lower part defined by a cone-shaped closed extremity, the lower part forming a chamber configured to receive the liquid; and

a piston comprising an upper part, a lower part, and a window oriented towards the cone-shaped closed extremity of the cell, the piston being slideable in the cell and sealing the cell in a gas-tight manner; and

(b) a monitoring system for visually monitoring contents of the chamber.

12. The assembly according to claim 11 , comprising a temperature-regulated enclosure surrounding the cell.

13. The assembly according to claim 11 , comprising at least one temperature sensor.

14. A method for determining volume of a liquid in a hydrocarbon fluid sample, the method comprising:

introducing a hydrocarbon fluid sample into a cell of a device for determining a volume of liquid in the hydrocarbon fluid sample, the device including:

the cell comprising an upper part defined by a tubular sidewall and a lower part defined by a cone-shaped closed extremity, the lower part forming a chamber configured to receive the liquid; and

a piston comprising an upper part, a lower part, and a window oriented towards the cone-shaped closed extremity of the cell, the piston being slideable in the cell and sealing the cell in a gas-tight manner;

decreasing pressure inside the cell by sliding the piston in the cell; and

measuring the volume of liquid present in the chamber.

15. The method according to claim 14 , wherein the hydrocarbon fluid is a gas condensate.

16. The method according to claim 14 , wherein the pressure is decreased by one or more decrements, each decrement being from 0.1 to 50 bar relative to initial pressure inside the cell.

17. The method according to claim 14 , wherein the measuring the volume of liquid is carried out by visually monitoring the chamber and determining position of a liquid-gas interface on a peripheral surface of the cone-shaped closed extremity.

18. The method according to claim 17 , wherein visually monitoring the chamber is carried out through the window of the piston, or wherein the position of the liquid-gas interface is determined owing to at least one marking present on the peripheral surface of the cone-shaped closed extremity.

19. The method according to claim 14 , wherein the decreasing the pressure and the measuring the volume of liquid are repeated a plurality of times.