When drilling for oil and gas became more challenging and well profiles became more deviated, there was a concern that a drill pipe tool joint might wear through casing. The first laboratory test to investigate the potential damage to the casing was developed by Maurer Engineering in the early 1990’s. Some of you may remember the Casing Wear Test being referred to as DEA 42.
In that initial test program, in which tool joints, hardbanding materials and even tungsten carbide overlay was tested, the results listed values such as “Friction Factors” and “Wear Factors”. To be approved for hardbanding, the Wear Factor number had to be below a value of 2.0. A value above 2.0 was considered a failure.
The Maurer Casing Wear Testing Equipment was purchased by Mohr Engineering, which is now an entity of Stress Engineering. After working with the Maurer testing equipment, Mohr Engineering determined that the test results were inconsistent. The results of the Maurer testing were also inconsistent due to the type of casing utilized in many of the tests. For the Maurer test, the specification for the casing allowed for a wide range of material properties which added to the unreliability of comparable testing results. Mohr made several changes to the equipment to improve consistency of the results. Duraband was developed and introduced to the Oil and Gas Industry after Mohr acquired the casing wear testing equipment. Therefore, the only casing wear test results for Duraband are from the Mohr testing. Furthermore, the test results are now identified differently. There is no longer a pass/fail result, but simply a set of values that are documented in the testing report. Also, the friction factors identified in both tests cannot be compared.
Postle Industries has been asked numerous times if there is a correlation between the Mohr test and the Maurer version. There is simply no correlation between the test results. However, in various different testing specifications with the improved equipment and procedure, Duraband has shown consistently low friction against casing, causing around 50% less damage than a tool joint with no hardbanding. The most proven and effective guard against casing wear is to have proud, casing friendly hardbanding such as Duraband NC applied to the tool joints and center wear pads of the drill string.
