Wave Propagation Resistivity Sub


APS's WPR™ Wave Propagation Resistivity sub is a spatially compensated, dual-frequency (400 kHz and 2 MHz), dual spacing device designed for wireline-equivalent logging while drilling (LWD) and measurements after drilling (MAD) services in all well types.




Pore pressure trend analysis

Casing point selection

Wireline replacement

Logging while tripping

Logging with and without the flow switch enabled (for air- and foam-drilled wells)

Features & Benefits

  • Provides real-time compensation.

  • Eliminates invasion effects due to measurement delays.

  • Improves accuracy by canceling variations in receiver channels.

  • Operates in all mud types, including oil-based and salt-saturated.

  • Provides real-time resistivity with flexible transmission formats.

  • High-resolution data is stored in downhole memory which can be retrieved and processed during trips.

  • APS provides a complete set of software-enabled borehole corrections and applications with WPR, including a dipping bed model for geosteering.

  • Pressure While Drilling (PWD) option available for 4.75 in. (121 mm), 6.75 in. (172 mm) and 8.0 in. (204 mm) WPR.

  • Low operating power for maximum battery life; designed to run with turbine alternator and 0x/1x/2x/3x battery (10 cell DD), or 3x/4x batteries.


  • Available tool sizes: 3.5 in. (89 mm), 3.75 in. (95 mm), 4.75 in. (121 mm), 6.75 in. (172 mm) and 8.0 in. (204 mm).

  • Symmetrical design with centrally located receive antennas.

  • Interfaces directly with APS SureShot™ MWD.

  • Hatch cover for easy access to tool programming and data dump port.