Abstract: This is an improved blast joint for subterranean wells which is ideally suited for applications where corrosive compounds such as hydrogen sulfide and carbon dioxide are encountered. The blast joint comprises a plurality of temperature and corrosion resistant hard rings which are in a stacked end face-to-face array, coaxially carried on a length of tubing. The rings are resiliently compressed in the array by spring washers interspaced by flat washers and this assembly is retained by end collars distally carried on the tubing. The end collars which are employed in this invention have a collet type construction; each collar comprising a clamp ring slidably received over the end of the production tubing, having an internally threaded outer end and a tapered inside wall. A collet sleeve with a tapered outside wall is received in the clamp ring.

Abstract: Means is provided in a blast joint, for an oil well, whereby the elements of the blast joint are designed and organized to overcome adverse external conditions encountered in the installation of the joint, as well as those encountered in the operation of the joint in the well, to maintain the structure and operability of the blast joint in a condition favorable to its effectiveness in protecting the production tubing from erosion at its production location in the well.

Abstract: The invention provides a blast joint which comprises basically an extended series of short cylindrical rings preferably rectangular in longitudinal axial section, composed of an abrasion resistant material such as cemented tungsten carbide, and disposed coaxially in contact with each other between end retaining rings mounted upon a supporting steel tube which comprises a single section or joined sections of a production tube.