Flexible casing for well boreholes

• US 5,269,570 A
• Filed: 04/17/1991
• Issued: 12/14/1993
• Est. Priority Date: 04/17/1991
• Status: Expired due to Term

• Current Assignee: Dwight S. Nunley
• Original Assignee: Dwight S. Nunley
• Inventors: Nunley, Dwight S.
• Primary Examiner(s): Nicholson, Eric K.
• Application Number:
  US07/686,668
• Time in Patent Office: 972 Days
• Field of Search: 285/223, 285/226, 285/227, 285/228, 285/114, 285/299, 285/300, 285/302, 285/229, 166/242, 166/175, 175/320, 138/121
• US Class Current: 285/229
• CPC Class Codes: E21B 17/08 Casing joints
• CPC Class Codes: F16L 51/022 with a single corrugation

Abstract

Tubulars for casing a well borehole which are drilled by high angle or horizontal drilling techniques. The tubulars contain an annularly disposed upset whose cross sectional shape is omega-like. This omega-like upset enables the tubulars to be set around the curved section of the borehole without detrimental buckling.

Claims

1. A flexible metal tubular casing for well boreholes which consists essentially of a tubular casing containing at least one annularly disposed upset having a cross-section which is omega-like in shape, which upset projects into the tubular wherein only the portion which projects into the tubular is filled with an elastomeric material.

2. The tubular of claim 1 wherein the annularly disposed upset is perpendicular to the longitudinal axis of the tubular.

3. A metal tubular for connecting two sections of casing tubulars for subterranean wells, which metal tubulars are characterized as consisting essentially of being threaded at both ends and containing at least one annularly disposed upset having a cross-section which is omega-like in shape which upset projects into the tubular and is filled with an elastomeric material.

4. The tubular of claim 3 where in the annularly disposed upset is perpendicular to the longitudinal axis of the tubular.