MT > MT for onshore oil discovery
  • Step 1: Survey
    Approximately 1,020 MT measurements were conducted on a grid that remained mostly square despite the topography. Spacing between measurements was 200 meters and 400 meters between profiles. Measurements were conducted overnight for durations more than 8 hours in order to calculate frequency responses down to 1,000 seconds.
    Note the position of the red circles for the positive exploration wells, the position of the green circles for the negative outcomes, and the a-priori position of the fault across the anticline

  • Step 2: Field equipment
    Equipment used for the survey was designed for high production, commercial surveys. Approximately 18 measurements were conducted every day. For this kind of high production survey that can last several months, the equipment must be capable of being:
    1. reliable, lightweight and very simple to use
    2. operated by technicians that can rotate easily without slowing down production
    3. provide advanced QA/QC tools back to camp to maintain production at optimized levels

  • Step 3: Modern permanent remote reference system
    25% of the measurements had 5 channels (Ex, Ey, Hx, Hy, Hz ) and 75% of them were only 2 channels (Ex, Ey) which allowed cost saving on magnetic sensors and permit faster daily productions.
    All measurements were remotely referenced to a far (> 20 km) permanent measurement. The so-called remote reference technique allow better time series processing by rejecting incoherent signals (noise) between local and remote . The illustration shows a modern permanent remote reference connected on the internet. Newer remote reference systems do not need to be served by sending data over internet which is important for extensive surveys.