US 8,281,866 B2Granted

Production tubing drain valve

AssigneeMSI Machineering Solutions Inc.

InventorsLynn P. Tessier, John P. Doyle

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Abstract

A tubing drain valve in a production tubing string, positioned above a pump, is operated to open drain ports in the housing for draining produced fluids from the production tubing when the pump is shut off. The drain valve incorporates a check valve assembly which is freely moveable within the drain valve to shift a sleeve to open and close the drain ports. An uphole end of the check valve assembly is above the sleeve and seals to the top of a sleeve to shift the sleeve downhole and open the drain ports. A downhole end of the check valve is positioned below the sleeve in the valve. When the pump is turned on, the downhole end of the check valve assembly moves uphole to seal to the sleeve, creating a positive force to lift the sleeve to block the drain ports. The produced fluids flow through the valve and the production tubing to surface. The positive force minimizes the effect of fouling of the valve due to debris above the valve which might otherwise result in failure to shift the sleeve uphole, leaving the drain ports open.

Claims13

Dependent claims

A tubing drain valve for incorporation between a production tubing string and a pump, the tubing drain valve comprising:

a housing having an uphole end for connection to the production tubing string above the pump and a downhole end for connection to the pump, downhole of the housing, the housing having a valve bore in communication with fluid in the tubing string and the pump;
one or more drain ports in the housing communicating with the valve bore;
a sleeve fit to the valve bore and being axially moveable in a reciprocating action in the valve bore, the sleeve having a central bore therethrough;
a first check valve positioned downhole of the sleeve for
sealing the central bore at a downhole end of the sleeve for forming a downhole piston face, fluid from the pump acting thereat to lift the sleeve uphole to block the one or more drain ports in a production position;
and
unsealing from the central bore for permitting fluid to flow therethrough in the production position;
a second check valve positioned above the sleeve for
unsealing from the central bore at an uphole end of the sleeve for permitting fluid to flow therethrough in the production position;
and
sealing the central bore for forming an uphole piston face, fluid in the production tubing string thereabove acting thereat to move the sleeve downhole to open the one or more drain ports in a drain position for draining fluid from the production tubing string therethrough.

8 more elements

A method for operating a tubing drain valve, positioned between a production tubing string and a pump, for blocking one or more drain ports in a valve housing in a production position for producing fluid through a valve bore in the housing when the pump is operating and opening the one or more drain ports in a drain position for draining fluid from the production tubing when the pump is stopped, the method comprising:

receiving fluid from the pump when operating the pump to flow fluid uphole;
shifting a first check valve axially uphole to seal a central bore of a sleeve housed in the valve bore at a downhole end of the sleeve, for forming a downhole piston face;
the fluid acting at the downhole piston face;
lifting the sleeve to move axially uphole within the valve bore to block the one or more drain ports in the production position,
arresting the uphole movement of the first check valve;
and
lifting the sleeve to unseal at least the first check valve from the central bore to permit the fluid to flow therethough
receiving fluid from the production tubing when the pump is stopped for ceasing the flow of fluid uphole;
moving a second check valve downhole to seal the central bore at an uphole end of the sleeve and for forming an uphole piston face, fluid in the production tubing thereabove acting at the uphole piston face;
and
shifting the sleeve downhole to open the one or more drain ports in the drain position.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/726,044Filed 17 Mar 2010 · us provisional application
Priority: 11 May 2009
Published: US 2010/0282476 A111 Nov 2010
Granted: 9 Oct 2012
Term ends: Not estimatedThe source records don’t support an estimate.