Low heat conductive frangible centralizers

A centralizer for use in a tubing string comprising a central tubular section connectable into a tubing string and having a portion of reduced outer diameter extending from one end and forming an annular shoulder at the junction with the normal diameter portion of said tubular section intermediate the end of said tubular section, a cage section slidably engageable over said reduced outer diameter portion of said tubular section for abutment against said annular shoulder, said cage section comprising a pair of annular collars maintained in fixed spaced apart position by a plurality of longitudinally extending spacer strips connected between said collars, each of said spacer strips having flanged portions on the outer sides thereof, a plurality of furfuryl alcohol impregnated prefired cordierite lugs, each of said lugs having an enlarged base portion engaged under opposing flanged portions of adjacent spacer strips and a removal collar connected on the end of the reduced diameter portion of said tubular member to disconnectably connect said lugs on said tubular section.

A centralizer for use in a tubing string comprising a central tubular section connectable into a tubing string;

• a longitudinally split cage section engageable around said tubular section, said cage section comprising a pair of split annular collars maintained in fixed spaced apart position by a plurality of longitudinally extending spacer strips connected between said collars, each of said spacer strips having flanged portions on the outer sides thereof, a plurality of furfuryl alcohol impregnated prefired cordierite lugs, each of said lugs having an enlarged base portion engaged under opposing flanged portions of adjacent spacer strips and snap rings engaging each of said split annular collars to disconnectably connect said annular collars and said lugs on sia dtubular section.

A centralizer for use in a tubing string comprising a central tubular section connectable into a tubing string, a plurality of undercut longitudinally extending grooves in said tubular section, a plurality of radially extending furfuryl alcohol impregnated prefired cordierite lugs having an enlarged base portion slidably engaged in said grooves of said tubular member, and means disconnectably connecting said lugs in said grooves.