Patent · US Expired

Flexible centralizer

US4938299A · kind A · utility

54Cited by
10References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 27, 1989
Grant dateJul 3, 1990
Priority date
Expiry dateJul 27, 2009

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE21B17/1064
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A downhole centralizer is provided for positioning along a drill pipe string passing through a deviated well bore. A centralizer body is connected to an upper sub by a plurality of lobe-shaped connectors which permit angular deviation of the central axis of the upper sub with respect to the central axis of the centralizer body. The centralizer body is preferably connected to a lower sub by similar lobe-shaped connectors. The opposite ends of each of the upper and lower subs are threaded for fixed engagement with respective upper and lower pipe joints in the tubular string. A flexible flow conduit is positioned within a passageway through the centralizer body, and a pair of upper and lower sealing member are provided to maintain sealed engagement between the respective upper and lower subs and the flow conduit for transmission of fluid through the centralizer. The centralizer of the present invention may be reliably used to center the tubing string within the deviated portion of a borehole, thereby reducing torque lossed to the drill bit and wear on the drill string.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.