Desanding apparatus and a method of using same

1. A desanding device for removing at least particulates from a multiple-phase fluid stream containing at least gas, liquid and entrained particulates, the desanding device comprising:

a vessel forming a treatment chamber, the treatment chamber having a fluid inlet for receiving the fluid stream adjacent an upper portion thereof and collecting particulates at a lower portion thereof, a top wall and bottom wall, said bottom wall having a non-zero angle of inclination with respect to a horizontal plane, and

a recovery chamber comprising a conduit fluidly connected to the treatment chamber, the conduit having

a first upper port formed through the conduit and in fluid communication with the upper portion of the treatment chamber for receiving gas therefrom,

a second lower port formed through the conduit and in fluid communication with a lower portion of treatment chamber for receiving liquid therefrom, the second lower port at an elevation below the first port, and

a fluid outlet, at an elevation intermediate the first upper and second lower ports and at an elevation lower than the fluid inlet, for discharging a particulate-free gas and a particulate-free liquid.

2. The desanding device of claim 1 wherein the recovery chamber is external to the vessel.

3. The desanding device of claim 1 wherein the conduit is located within the vessel.

4. The desanding device of claim 1 wherein the treatment chamber further comprises a particulate drain for removing particulates from the lower portion of the treatment chamber.

5. The desanding device of claim 1 wherein a cross-sectional area of the recovery chamber is much smaller than a cross-sectional area of the treatment chamber.

6. The desanding device of claim 1 wherein a liquid interface is formed in the recovery chamber and the treatment chamber at about the elevation of the fluid outlet.

7. The desanding device of claim 1 wherein the treatment chamber further comprises a flow barrier between the fluid inlet and the first upper port for directing the fluid stream thereabout.

8. The desanding device of claim 1 wherein a first portion of the recovery chamber is external to the vessel and fluidly connected to the treatment chamber within the vessel at the first upper port and a second portion of the recovery chamber is located within the vessel and fluidly connected to the treatment chamber within the vessel at the second lower port.

9. The desanding device of claim 1 wherein the treatment chamber further comprises a particulate drain for removing particulate from the lower portion of said treatment chamber, the particulate drain comprising a sand accumulation chamber sandwiched between an inlet valve and a discharge valve for forming an airlock.

10. The desanding device of claim 9 further comprising a particulate detector to detect particulate accumulation in the sand accumulation chamber through the inlet valve and to periodically open and close the particulate drain.

11. The desanding device of claim 9 wherein the inlet and discharge valves are controlled automatically with a timer or a particulate detector to periodically open and close the particulate drain.

12. The desanding device of claim 1 wherein the conduit is external to the vessel and fluidly connected to the treatment chamber within the vessel at the first upper port and at the second lower port.

13. The desanding device of claim 12 wherein the conduit comprises a vertically oriented conduit portion extending upwardly from the second lower port and to the fluid outlet.

14. The desanding device of claim 1 wherein the treatment chamber has a bottom wall at an angle of between about 25 and about 90°.

15. The desanding device of claim 1 wherein the treatment chamber has a bottom wall at or greater than an angle of repose of the particulates accumulated therein.

16. The desanding device of claim 1 wherein the conduit comprises a baffle in the vessel that divides the vessel into a treatment chamber and the recovery chamber, the first upper port and the second lower port formed through the baffle.

17. The desanding device of claim 16 wherein the fluid outlet extends downwardly into the recovery chamber to an elevation intermediate the first upper port and the second lower port.

18. The desanding device of claim 1 , wherein the fluid inlet extends adjacent to or along the bottom wall of the vessel and the second lower port is along the top wall.