Gail E Nelson

US Patent:

20100018779, Jan 28, 2010

Filed:

Jul 24, 2008

Appl. No.:

12/179469

Inventors:

Navish Makkar - Houston TX, US
Wei Tang - Katy TX, US
Gordon Whipple - Spring TX, US
Tommy Laird - Cypress TX, US
Gail Nelson - Tomball TX, US

Assignee:

SMITH INTERNATIONAL, INC. - Houston TX

International Classification:

E21B 10/00

US Classification:

175382, 175401

Abstract:

A secondary cutting structure for sure in a drilling assembly, the secondary cutting structure including a tubular body and a block, extendable from the tubular body, the block including a first arrangement of cutting elements disposed on a first blade and a second arrangement of cutting elements disposed on a second blade, wherein the second arrangement is a modified redundant arrangement. Also, a secondary cutting structure for use in a drilling assembly, the secondary cutting structure including a leading blade disposed on a first block and a trailing blade disposed on the first block adjacent the leading blade. Additionally, the secondary cutting structure includes a unique blade disposed on a second block, wherein a gage portion of at least one of the blades has a length between 30% and 45% of a total blade length.