Patent ID: 6634427
Filing Date: 2003-10-21
Classification: E21B

Abstract:
A method of manufacturing a drill string section including an internal passage extending along a substantial portion of its length, the method comprising the steps of:(a) providing a drill string section comprising a first end, an opposing second end, an outer surface, and a centrally disposed bore extending from the first end to the second end so as to form a wall between the bore and the outer surface; (b) separating the drill string section into first and second portions, the first portion comprising the first end and a third end formed by said separation, the second portion comprising the second end and a fourth end formed by said separation; (c) forming a first blind and generally axially extending passage through the wall from the third end towards the first end and to a position spaced apart from the first end; (d) forming a second blind and generally axially extending passage through the wall from the fourth end towards the second end and to position spaced apart from the second end; (e) joining the third end of the first portion to the fourth end of the second portion so as to form a unitary section of drill string in which the first and second passages are misaligned; and (f) forming a connecting passage from the outer surface of the drill string section that intersects the first and second passages, whereby the connected first and second passages define the drill string section internal passage.