Abstract: A blast joint for protecting production tubing passing through a producing zone including one or more tubing joints of sufficient length to extend through the producing zone, erosion resistant carbide rings mounted on the tubing joints in end-to-end array, ring retainers at each end of the erosion resistant rings to hold the rings on the tubing joints, and one or more elastomer spacer rings engaged with the erosion resistant rings for holding the erosion resistant rings in end-to-end array and being yieldable axially by outward displacement in response to movement of the erosion resistant rings along the tubing joint to permit the rings to move in response to lateral bending of the tubing joints and impact forces on the blast joint during assembly and installation to minimize damage to the erosion resistant rings. The carbide rings are larger than the tubing joints to permit lateral bending of the tubing joints in the rings without stressing the rings.

Abstract: The present invention utilizes a centralizer having a plurality of segmented stress risers. The segmented stress risers are designed to allow sufficient strength to maintain the tubing in a centralized downhole location, while to allow for the stress relief grooves to be sheared off when a wash pipe or similar device is utilized to clean out any unwanted build up of material or deposits in the borehole. Once the segments have been sheared off they can be circulated out of borehole.

Abstract: A multi-joint blast joint comprising a series of standard length joints of production tubing is disclosed. The blast joint includes a series of cylindrical rings composed of an abrasion resistant material mounted about the tubular tubing joints forming a protective shield about the production tubing. A movable sleeve formed of cylindrical abrasion resistant rings is selectively shiftable to enclose and shield the tubing connection assemblies joining the production tubing forming the blast joint. A slip sleeve is mounted about the blast joint providing a pipe slip engaging surface for suspending the blast joint in the well bore. The production tubing and abrasion resistant rings form a blast joint whose length exceeds the standard length of a single joint of production tubing.