Paul F Conover

US Patent:

7748473, Jul 6, 2010

Filed:

Jul 11, 2008

Appl. No.:

12/218211

Inventors:

Lawrence E. Wells - Yorba Linda CA, US
Preston Fox - Fountain Valley CA, US
Cliff Swiontek - Brece CA, US
Svein Stubstad - Houston TX, US
Howard L. Ervin - Spring TX, US
James D. Brugman - Spring TX, US
Paul Conover - Cypress TX, US

Assignee:

National Oilwell Varco, L.P. - Houston TX

International Classification:

E21B 19/00

US Classification:

175 52, 166 7751, 175 85

Abstract:

A top drive system for wellbore operations, the top drive system including motor apparatus, a main shaft driven by the motor apparatus, the main shaft having a top end and a bottom end, a quill connected to the main shaft, a gear system interconnected with the quill and the motor apparatus, and a multi-seal system for sealing against the quill. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C. F. R. 1. 72(b).

US Patent:

20070251705, Nov 1, 2007

Filed:

Apr 28, 2006

Appl. No.:

11/414514

Inventors:

Lawrence Wells - Yorba Linda CA, US
Svein Stubstad - Houston TX, US
Howard Ervin - Spring TX, US
James Brugman - Spring TX, US
Paul Conover - Cypress TX, US

International Classification:

E21B 19/00

US Classification:

166387000, 166088100, 175195000

Abstract:

A multi-seal sealing assembly with multiple seals so that when one seal wears out another can be moved into sealing position; and a top drive system for wellbore operations with such a sealing assembly; the sealing assembly in one aspect having a seal carrier movable to move at least one secondary seal into sealing position when a primary seal has worn out.