Figure 1:  VEDAQ-2000 Buggy Shoe Includes Only One (1) Hall Sensor for Wall Loss Detection

Figure 2:  TubePRO In-plant Shoe Load Includes Only One (1) Hall Sensor for Wall Loss Detection

Inspection shoes used in New Tech Systems’ VEDAQ-2000 portable and TubePRO in-plant pipe inspection systems (figure 1 and 2) were examined and found to each contain one (1) search coil for the detection of transverse flaws and only one (1) Hall sensor for the detection of wall loss defects, including LOCALIZED WALL LOSS.

Localized wall loss (see figures 3, 4, 5 & 6) may be defined as areas of missing metal, often caused by corrosion or erosion, which form during the process of drilling for and production of gas and oil.  These defects can be very small like the size of a pencil eraser or can be much wider and many inches in length.  These localized loss of metallic areas can be 95% or deeper into the body wall of the pipe.  Localized wall loss is one of the primary defect types responsible for rejection of used drill pipe and used production tubing.  Localized wall loss is typically not detectable by induction search coils.

Evaluation of the New Tech Systems (NTS) electromagnetic inspection shoes revealed a serious deficiency.  Both shoes are incapable of providing 100% circumferential coverage of the pipe’s body wall for localized wall loss defects.  Calculations reveal that the MAXIMUM circumferential coverage for localized wall loss is limited to 17.2% for an inspection head with eight (8) inspection shoes (each containing only one Hall sensor).  The total coverage becomes even less as the outside diameter (OD) of the pipe increases, creating a larger gap of more than two (2) inches between the eight small area Hall sensors.  In the most extreme case on 6-5/8” OD drill pipe, a mere 6.2% of the pipe’s circumference is covered during inspection for LOCALIZED WALL LOSS.

New Tech System’s advertising states that their WALL LOSS method “monitors 100% of the wall surface”.  However, simple math and approximately ten minutes of performance testing revealed that this statement is not true and consequently, is impossible to justify.

Figure 3 and 4 show localized wall loss defects used during testing of a VEDAQ-2000 system (shown in figure 7, 8 and 9) which provided NO signal response from the system’s Hall sensors, after the unit was configured using a New Tech reference standard.  The lack of indication from the damaged area in the pipe’s O.D. shows that New Tech’s one (1) Hall sensor design provides far less than the claimed 100% wall surface coverage.  And, as expected, the search coils located within each of the eight (8) inspection shoes of the VEDAQ-2000 were ineffective in locating the areas of localized wall loss.

 

Additional system limitations were also discovered during testing !

Contact us at 210-657-7607 or sales@oem-usa.com for more information.