The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 16, 2002
Filed:
Dec. 08, 2000
Applicant:
Inventors:
Detlef Hahn, Hannover, DE;
Friedhelm Makohl, Hermannsburg, DE;
Assignee:
Baker Hughes Incorporated, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 7/08 ;
U.S. Cl.
CPC ...
E21B 7/08 ;
Abstract
The present invention provides apparatus and method for drilling a wellbore wherein a pilot wellbore section is drilled with a bit which section is enlarged by a trailing underreamer to the desired size. One or more steering sections between the underreamer and the drill bit are utilized for maintaining and changing the drilling direction. Each steering section includes a plurality of independently adjustable force application devices on a non-rotating sleeve. If an expandable liner is used, then an expansion device disposed above the underreamer expands the liner during retrieval of the drilling assembly to the surface.