TEMP-VEL

TEMP-VEL (Transient ElectroMagnetic Prospecting - Vertical Electric Lines) is the first technology developped and patented by PetroMarker.

TEMP-VEL differs notably for the previous marine EM technologies known under various names such as CSEM (*), MCSEM, TDEM, SBL...All of these operate similarly: horizontal-horizontal dipoles used in frequency domain and at large offsets.

Working in time-domain, at short offset or near zone, with alternate pulsing and receiving sequences, TEMP-VEL avoids interferences created by the air wave and the direct signal.

As s result, the processing of the data is way easier and faster than with the other technologies.

The main features of TEMP-VEL are:

• Accuracy - Due to the short offset set-up (500 to 1 700 m between transmitter (Tx) and receivers (Rx), the geological layers "seen" by TEMP-VEL are within a volume directly under the dipole transmitter-receiver,
• Sensitivity - The vertical component of the EM filed is more sensitive than the horizontal one. If the signal handled by TEMP-VEL is more sensitive, it is also much weaker.
• The necessary very low noise floor receivers have therefore been developped. Penetration - Depending on the geological formations (nature and resistive contrast) and transmitter output, the penetration of TEMP-VEL may reach 5 000 m below seabed,
• Vertical dependant - The receiver antenna must be as vertical as possible to avoid interfering noise from the horizontal component. PetroMarker has developped the so-called tripods which allow both adjustment of the verticality and control of the verticality.

(*) TEMP-VEL is sensu strico a CSEM (Controlled Source ElectroMagnetic) technology, but since this acronym is now commonly used to refer to horizontal-frequency domain technologies, we prefer not to use it.