Cable Installation Suggestion
01
Wire Embrittlement & Wrap Test
For wireline logging cables that have been deployed downhole and operated in the field, operator can assess wire embrittlement through a wrap test. The tensile strength grades of wire are typically classified as:
1870MPa
Standard Grade
2160MPa
Standard Grade
2350MPa
EHS (Extra High)
2600MPa
EEHS (Extra Extra)
Cables manufactured with 2350MPa and 2600MPa grade wires are designated as EHS (Extra High Strength) and EEHS (Extra Extra High Strength) cables. This indicates that, compared to cables of the same outer diameter, these two types offer greater breaking strength and safe working load.
Standard Wrap Test
1870MPa / 2160MPa
Mandrel Diameter = 1 × Wire Diameter
In the wrap test, wires can be wrapped five times clockwise and five times counterclockwise around a mandrel with a diameter equal to the wire's own diameter. If the wire is in good working condition, it should not break during this procedure.
Specialized Wrap Test (EHS/EEHS)
2350MPa / 2600MPa
Mandrel Diameter = 2 × Wire Diameter
EHS and EEHS cables should not undergo the standard wrap test because the specific steel alloy formulation used in these wires is more susceptible to severe bending stress. Instead, the wire should be wrapped around a mandrel with a diameter twice that of the wire itself (Fig. 1), following the same procedure of five wraps in each direction.