Voltage Protection Modules

Voltage Protection Modules (VPM) tools perform various functions in relation to voltage and current blocking or passing, depending on the operator’s requirements. They are primarily used to provide additional safety in tractor and perforating operations.

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The VPM-G type tool (and its derivatives) allows the detonator, or tool-string, below it to be electrically disconnected via a double-pole switching mechanism. This protects the toolstring from any voltage applied at the upper head of the VPM; e.g. while tractoring a gun or production logging (PL) string in hole. The tool/detonator below can have a double ground applied when the VPM is in safe mode.

The VPM-H type tool (and its derivatives) allows the user to switch the upper head connection between two lines, and is used either to switch between otherwise incompatible tools within the same toolstring or to switch power between two ballistics devices.

The tool is controlled by a surface control panel (VCP-A or MPP-B), which utilises a digital telemetry system. It can also be supplied with custom interlocks to prevent the accidental sending of current while the downhole switch is in fire mode.

Product features

  • Disconnects lower tool from line and grounds detonator hot wire for safety.
  • Can be used to switch between two lines in tractor operations.
  • High voltage and current rating for tractor operations.
  • Complies with API RP 67 guidelines.

Product Application

  • Allows power and telemetry to be switched between 2 electrically incompatible tools.
  • Isolates perforating guns from tractor in accordance with API RP 67.