DESANDING APPARATUS AND SYSTEM

• US 20130206007A1
• Filed: 02/13/2012
• Published: 08/15/2013
• Est. Priority Date: 02/13/2012
• Status: Active Grant

• Current Assignee: Specialized Desanders, Inc.
• Original Assignee: Specialized Tech, Inc. (Specialized Desanders, Inc.)
• Inventors: HEMSTOCK, Christopher A
• Granted Patent: US 8,945,256 B2
• Time in Patent Office: Days
• US Class Current: 95/216
• CPC Class Codes: B01D 21/0003 Making of sedimentation devices, structural details thereof, e.g. prefabricated parts
• CPC Class Codes: B01D 21/2405 Feed mechanisms for settling tanks
• CPC Class Codes: B01D 21/2483 Means or provisions for manually removing the sediments
• CPC Class Codes: B01D 21/2494 provided with means for the removal of gas, e.g. noxious gas, air
• CPC Class Codes: B01D 2221/04 Separation devices for treating liquids from earth drilling, mining separation of well effluents E21B43/34, flotation in general B03D1/00
• CPC Class Codes: E21B 43/35 specially adapted for separating solids down-hole drilling fluid separation systems E21B21/002; separating solids from drilling fluids E21B21/065

Abstract

A desanding system has an elongated vessel that is tilted at a non-zero inclination angle. A fluid inlet at the vessel'"'"'s upper end discharges a gas stream having entrained liquids and particulates and a fluid outlet into a freeboard portion formed adjacent an upper portion of the vessel above a gas/liquid interface formed below the fluid outlet. A belly storage portion is formed below the interface. The freeboard portion of the vessel has a freeboard cross-sectional area that diminishes along the interface from the fluid inlet to a fluid outlet spaced away from and lower than the fluid inlet. The cross-sectional are of the freeboard portion causes precipitation of the entrained liquids and particulates therefrom and collect in the belly portion of the vessel. A desanded gas stream, being free of a substantial portion of the particulates is removed from the vessel through the fluid outlet.

Claims

1. A desanding system for receiving a gas stream containing entrained liquid and particulates comprising:

a vessel which is elongated along a longitudinal axis and that is inclined from a horizontal at a non-zero inclination angle, the vessel further having a fluid inlet adjacent an upper end of the vessel for discharging the gas stream into the vessel at an inlet velocity, the gas stream travelling down the vessel to a fluid outlet spaced along the longitudinal axis from, and lower than, the fluid inlet, the vessel having

a gas/liquid interface at the fluid outlet having a belly storage portion formed therebelow and a freeboard portion formed adjacent an upper portion of the vessel above the interface, the freeboard portion having a freeboard cross-sectional area which diminishes from the fluid inlet to the fluid outlet and wherein a freeboard velocity adjacent the fluid inlet is less than the inlet velocity, and wherein

the freeboard velocity being such that the entrained liquids and particulates fall out of the gas stream and collect in the belly storage portion, and

wherein a desanded gas stream flows out of the freeboard portion and out the fluid outlet, being free of a substantial portion of the particulates.

2. The desanding system of claim 1 wherein fluid inlet has a discharge end, the discharge end oriented for discharging the gas stream into the freeboard portion.

3. The desanding system of claim 1 wherein discharge end of the fluid inlet directs the gas stream into the freeboard portion and parallel to the longitudinal axis.

4. The desanding system of claim 1 wherein the fluid inlet further comprises a replaceable nozzle having a discharge end oriented for discharging the gas stream into the freeboard portion.

5. The desanding system of claim 1 wherein the replaceable nozzle is connected to the fluid inlet at a flange.

6. The desanding system of claim 1 wherein the gas stream emanates from a wellhead and the fluid inlet further comprises:

a discharge end for directing the gas stream into the freeboard portion and parallel to the longitudinal axis;

a receiving end for receiving the gas stream and orthogonal to the wellhead.

7. The desanding system of claim 1 further comprising:

a conduit for conducting a fluid stream containing entrained particulates from a wellhead, the conduit having a desander end; and

wherein the fluid inlet further comprises a discharge end for directing the fluid stream into the freeboard portion and oriented parallel to the longitudinal axis, and a receiving end for receiving the gas stream and oriented orthogonal to the desander end.

8. The desanding system of claim 1 wherein the inclination angle is variable for varying fluid stream conditions.

9. A method for desanding a fluid stream emanating from a wellhead, the fluid stream containing gas, entrained liquid and particulates, the method comprising:

providing an elongated vessel having a longitudinal axis, a fluid inlet adjacent an first end of the vessel and a fluid outlet spaced along the longitudinal axis from the fluid inlet

inclining the vessel at angle from horizontal at a non-zero inclination angle so that the fluid outlet is lower that the fluid inlet for forming a freeboard above the fluid outlet;

discharging the fluid stream from the fluid inlet, into the vessel and substantially parallel to the longitudinal axis for

establishing a liquid interface in a belly portion of the vessel, the belly portion and being formed below the fluid outlet, and

directing the liquid and particulates along a trajectory in the freeboard portion of the vessel to intercept a substantial portion of the particulates at the liquid interface for storage in the belly portion; and

recovering a desanded gas stream at the fluid outlet which is substantially free of particulates.