George W Duncan

US Patent:

7314091, Jan 1, 2008

Filed:

May 25, 2004

Appl. No.:

10/853568

Inventors:

Nathaniel Heath Wagner - Spring TX, US
George C. Duncan - Houston TX, US
Roddie R. Smith - Cypress TX, US

Assignee:

Weatherford/Lamb, Inc. - Houston TX

International Classification:

E21B 34/06

US Classification:

166386, 1663328

Abstract:

A subsurface safety valve is first provided. The safety valve generally comprises a tubular housing, an isolation sleeve disposed within an inner diameter of the tubular housing, with the isolation sleeve and the tubular body forming an annular area there between, a flow tube movably disposed along a portion of the annular area, and a flapper. The flapper is pivotally movable between an open position and a closed position in response to longitudinal movement of the flow tube in order to open and close the valve. Preferably, the annular area is isolated from an inner diameter of the isolation sleeve in the open position. A method is also provided that allows for a cementing operation to be performed through an open safety valve.

US Patent:

7543651, Jun 9, 2009

Filed:

Oct 21, 2005

Appl. No.:

11/255349

Inventors:

Roddie R. Smith - Cypress TX, US
Nathaniel H. Wagner - Spring TX, US
George C. Duncan - Houston TX, US

Assignee:

Weatherford/Lamb, Inc. - Houston TX

International Classification:

E21B 34/10

US Classification:

166386, 1663321, 1663328

Abstract:

The present invention generally relates to a non-elastomeric cement through tubing retrievable safety valve configured to control fluid flow through a production tubing string. In one aspect, a valve for use in a wellbore is provided. The valve includes a tubular body. The valve further includes a flow tube having a bore therethrough, wherein the flow tube is disposed in the tubular body to form an annular area therebetween. The valve further includes a flapper movable between an open position and a closed position in response to the movement of the flow tube. Additionally, the valve includes a sealing system constructed and arranged to substantially isolate the annular area from the bore, thereby substantially eliminating the potential of contaminants in the bore from entering into the annular area. In another aspect, a method of controlling fluid in a wellbore is provided.