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Carbide Blast Joints

     The purpose of the Carbide Blast Joint is to provide maximum protection against the erosive or blasting effect of oil or gas-produced sand/fines against the long string of tubing, in a dual completion well.

     CBJ, Inc furnishes carbide protection to cover the full spectrum of production tubing applications, whether our customer is utilizing conventional non-upset threaded and coupled connections, flush joint connections, or tubing within a screen on gravel packed section.  CBJ realized early on, that it was obvious no single assembly worked best in all wells.  Length of continuous perforations, need for high tensile strength, well depth and other considerations can effect the configurations of the assembly.  Some examples of these configurations to fit specific conditions follow.



The SLIMLINE Carbide Blast Joint goes anywhere you’d run A.P.I. tubing.

     The SLIMLINE Carbide Blast Joint is preferred by customers all over the world for its versatility and proven record of durability.  After its initial development to protect tubing ahead of need in third alternate zone completions, the SLIMLINE has proven its effectiveness in a variety of applications.  The SLIMLINE is easy to install wherever you need it.  And you get all the proven design and manufacturing that has given Carbide Blast Joints the finest performance record in the industry.

Slimline Specifications
Tubing Size
Nom., in.
Over Collar
1 1/2
2 1/16
2 3/8
2 7/8
3 1/2
4 1/2



THE COONIE CONNECTION Carbide Blast Joint with 100% Tensile Strength

     The Coonie Connection allows continuous carbide coverage over any number of conventional non-upset threaded and coupled connections.  The specialized rings achieve complete coverage without internal stress on any one ring.  Standard-sized carbide rings are used up to the collar.  There, a transition ring mates the standard rings with larger ID rings over the collar.  A weight distribution ring nearer the connection assures transfer of the carbide’s weight and compression over the collar.  A compensating ring allows the length of the carbide sheath over the collar to be modified for varying collar lengths.  When the Connie Connection is assembled over premium T&C connections such as Hydril Wedge, TC-4S, VAM or Mannesman, at least 100% tensile strength is achieved.  Non-upset, 8-roung T&C connections will maintain 90-95% tensile strength.  Using crossover couplings allows the Coonie Connection to be used in any string.  Minimum casing sizes recommended for the Connie Connection Carbide Blast Joint is 4-1/2-inch O.D. for the 2-3/8-inch tubing size, 5-inch for the 2-7/8-inch size, and 5-1/2-inch for the 3-1/2-inch size.  Should there be several intervals requiring protection, the Connie Connection can be assembled in any length to provide complete protection.

Coonie Connection Specs
Tubing Size, Nom.,
Final O.D. Over Collar
2 3/8
2 7/8
3 1/2



  Gravel Packed Sections

     The Slimline has proven to be a popular design for running inside the well screen on GRAVEL PACKED SECTIONS.  Despite the care taken with gravel packing, subsidence of the pack, incorrect sizing of gravel or screen, or erosion/corrosion of the screen or slotted liner can cause the full blasting effect of produced sand to reach the production tubing inside. By positioning a Carbide Blast Joint inside the screen or slotted liner, the tubing is completely protected from high-pressure production should the pack or liner ultimately fail.


Water, Steam and Fire flooding

     Another specialized assembly has proved effective in areas where steam and fire flooding are commonly used.  It is a relatively short Single-Blast-Joint used solely to protect the tubing where the flood enters the wellbore.  The Carbide Blast Joint is stable at much higher temperatures than those encountered in normal steam and fire flooding, with the rings remaining stable at temperatures in excess of 2000 deg. F.