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.

Date of Patent:
Dec. 05, 1995

Filed:

Feb. 09, 1995
Applicant:
Inventor:

Michael B Winfree, Anchorage, AK (US);

Assignee:

Atlantic Richfield Company, Los Angeles, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175 57 ; 175101 ; 175107 ; 175171 ; 175259 ; 175267 ;
Abstract

A wellbore is formed in the earth with an elongated, non-rotating tubular drillstem which may consist of a well casing or liner and including an expendable sub and reamer bit part connected to the lower distal end of the drillstem. A retrievable drilling fluid operated motor and drive member assembly are disposed in the drillstem. The motor and drive member include pressure fluid responsive mechanism for engagement with and disengagement from the reamer bit part to rotatably drive the reamer bit part and a central bit part connected to the drive member without rotating the casing type drillstem. The motor, drive member and central bit part may be retracted from the drillstem upon completion of drilling operations without retrieving the expendable reamer bit part.


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