REDUCED CAVITATION OILFIELD CHOKE

• US 20150041690A1
• Filed: 03/01/2013
• Published: 02/12/2015
• Est. Priority Date: 03/14/2012
• Status: Active Grant

• Current Assignee: National Oilwell Varco LP (NOV, Inc.)
• Original Assignee: T-3 Property Holdings, Inc. (NOV, Inc.)
• Inventors: McCaskill, Lane
• Granted Patent: US 9,611,952 B2
• Time in Patent Office: Days
• US Class Current: 251/127
• CPC Class Codes: E21B 34/025 Chokes or valves in wellheads and sub-sea wellheads for variably regulating fluid flow
• CPC Class Codes: F16K 3/246 Combination of a sliding valve and a lift valve
• CPC Class Codes: F16K 47/08 for decreasing pressure or noise level and having a throttling member separate from the closure member , e.g. screens, slots, labyrinths

Abstract

A choke with reduced cavitation and/or flashing due to a high pressure fluids passing through the choke includes a housing having a high pressure inlet port and a low pressure outlet port, and a cage positioned within the housing and having a passage for passing fluid therethrough. A plurality of beads are each positioned in the cage, such that fluid flows between the cage and the beads and between the beads when passing through the cage. Fluid pressure is reduced by the fluid passing through the cage, thereby reducing cavitation.

Claims

1. A choke with reduced cavitation and/or flashing due to high pressure fluids passing through the choke, comprising:

a housing having a high pressure inlet port and a low pressure outlet port;

one or more cages positioned within the housing and having one or more inlet ports to receive fluid into the cages and one or more outlet ports to allow fluid to exit the cages, wherein one of the cages comprises a bead cage;

an actuator;

a flow controller coupled to the actuator and configured to at least partially block the inlet ports into at least one of the cages; and

a plurality of beads positioned within the bead cage, such that fluid flows between the bead cage and the plurality of beads and between the beads when passing through the bead cage, and fluid pressure is reduced while fluid passes through the bead cage.

2. The choke of claim 1, wherein the flow controller comprises a control sleeve axially movable with the actuator to open and close the inlet ports into the bead cage.

3. The choke of claim 1, wherein another of the cages comprises a jet cage disposed upstream from the bead cage and the inlet ports of the jet cage receive fluids from the high pressure inlet port and the outlet ports of the jet cage pass fluid into the bead cage, wherein an interior of the jet cage is in fluid communication through the outlet ports with an interior of the bead cage.

4. The choke of claim 3, wherein at least one inlet port of the jet cage is positioned in a side of the jet cage and radially opposite another inlet port, such that jetstreams from the side inlet ports impinge within the sleeve.

5. The choke of claim 1, further comprising a lid removable secured to the bead cage to retain the plurality of beads in the cage.

6. The choke of claim 5, wherein the lid is adjustably engaged with the bead cage to compress a variety of quantities of beads loaded into the bead cage for different flow ranges of the choke.

7. The choke of claim 1, wherein at least a portion of a length of the bead cage inner diameter is threaded and a lid removable secured to the bead cage to retain the plurality of beads in the cage is formed with mating threads.

9. The choke of claim 1, wherein the cage is shrink fit onto a choke seat which is secured to a housing of the choke.

10. The choke of claim 1, wherein the beads are bonded to each other and to the cage.

11. The choke of claim 3, wherein the beads are bonded to each other and to the cage by a sintering operation.

12. The choke of claim 1, wherein the beads are spheroids.

8. The choke of claim 8, wherein the outlet ports of the bead cage are formed in the lid.