UTEM 4 Borehole

The UTEM 4 Borehole system - BHUTEM 4 - is a borehole EM system from Lamontagne Geophysics Ltd. with the ability to do simultaneous three-axis oriented down-hole UTEM measurements. Currently BHUTEM 4 uses a UTEM5 Receiver and the combination allows for data collection from up to three transmitter loops simultaneously. Three components from up to three different coupling angles - up to 9 different oriented components - in a single pass.

Orientation of the EM sensor is achieved by the combined use of three-axis magnetometer and temperature compensated three-axis accelerometer. The digital data are preprocessed down the hole, encoded, and transmitted to the surface by means of a single fibre optical link at a rate of 100k samples simultaneously for all components. Magnetometer data, accelerometer based tilt sensor data, temperature, and system monitoring data are multiplexed with the three-component EM data.

The key performance numbers of the system are:

  • 3400m depth capability
  • Very low deep hole system noise levels
  • Very high system gain fidelity for "on" time measurement use
    • Less than 0.05% late channel probe/receiver gain variation

The UTEM 4 BH system is composed of the UTEM 4 BH down-hole probe, the UTEM5 Receiver and up to three UTEM 4 or UTEM5 Transmitters. A field ready system would also include a BH UTEM winch, a winch motor controller, one or more fibre optic cable spools, inter-connecting cables, and wire laying accessories which are unchanged from those used in the BH UTEM 3 system.

The UTEM 4 BH down-hole probe has a maximum diameter of 38 mm for use in holes of BQ and greater diameter. The UTEM 4 BH data reduction and display software includes 3-axis data reduction oriented relative to a user specified drill section. Magnetometer, inclinometer and temperature data profiles can be plotted in addition to the EM data. Software is available for interactive 3D viewing of the vector fields.

UTEM 4 BH Brochure