Apparatus and method for improving the integrity of coupling sections in high performance tubing and casing

Abstract

A system and method for improving the seal integrity and useful life of tubing and casing strings fills the volume between the nose ends of facing tubing sections and the collar to which they are mutually joined with a temperature and corrosion resistant element having a smooth interior surface substantially flush with the inner diameter of the tubing or casing. During makeup of each successive section of the drill string, a center fill tool including an expansible tubular element is seated below the coupling area to be self-retained, by the use of pressure expansion of a cylindrical surface. A precise amount of a curable material is inserted into the volume bounded by the nose ends and the collars (the so-called "J area") and while the material is still flowable the coupling is made up by threading in of the next tubular element. When sufficient setting has taken place, which occurs quickly, a retrieving tool is lowered to grip the upper end of the insert which is configured internally to vent the pressurizing gas as upward force is exerted. Thus the center fill tool can be moved out of position and the string lowered into the well bore, the tool then being ready for makeup of the next succeeding coupling.

Dependencies are inferred from the claim text.