1. Multi-Transient ElectroMagnetics Multi-Transient EM Aug 2007

3. Resistivities of Rocks Diagram courtesy Henri Brasse http://userpage.fu-berlin.de~hbrasse

4. Fluid saturation and rock properties P-wave velocity is affected only slightly by hydrocarbon saturation in a porous rock. Resistivity can vary by more than an order of magnitude. Picture redrawn from Wilt M. and Alumbaugh D. 1998, The Leading Edge 17, 487-492.

5. Direct Resistivity Indicator Seismic traces Seismic amplitudes and attributes Logging measurements Logging before drilling MTEM Resistivity

8. Gas storage monitoring

9. Shallow Heavy Oil resistivity scale

10. Thrust Belt

11. Thrust belt

19. MTEM Global Operations Onshore Offshore

21. MTEM Hardware

22. Receiver station and battery Receiver box and battery in the line. Box with acquisition and telemetry electronics. Grounded with earth electrode.

23. Source Buggy and Unit Source buggy with generator and source unit. Source engineer with Zonge and control electronics.

24. Source Electrodes An array of 1 to 40 electrodes hammered into 80-100cm into the ground. Fenced off (3m) and manned when source cables are connected.

25. Source Safety system Source activation and emergency shut off at the source electrode array. Emergency shutoff cuts power to the entire system.

26. Source electrode transport Source electrode transport buggy. Low ground pressure buggy to transport the 40 electrodes per source pole location.

27. Land Operations

28. A Step Change in the use of EM Input Recording (combination of Earth and System Responses) Airwave Earth response

29. Impulse response - land Offset = 1 km Air Wave Earth Impulse Response

30. 1D model Source 1A.m Source Receiver (V) x = 1000m 500m 20 Ohm.m 500 Ohm.m Dx 25m

31. Impulse response Effect of fluid saturation Offset = 1 km

32. Impulse response – land Convolution with a system response Air Wave

33. Impulse response measurements Full Waveform Amplitudes Travel Time

34. Multi-Transient Theoretical PRBS In red Measured Signal In black

35. Deconvolution Input amps at source Output volts at receiver Deconvolved impulse response (ohms/m 2 /s)

36. Deconvolved Data – common offset Air Wave High peak amplitude and early arrival time indicate a resistor.

37. Data Processing Apparent resistivity Step Response Integration Peak picking Impulse Response

38. Inversion model and response Offset 1000m

39. Inversion model and response Offset 2000m

40. Inversion model and response Offset 2500m

41. Inversion model and response Offset 3000m

42. Inversion model and response Multi-offsets 2000m, 2500m and 3000m

43. Results summary 4 ways to detect hydrocarbons 2-D DC resistivity inversion Traveltime to resistivity mapping 1-D Occam Inversion 1800m Common offset section

45. Well Logs

48. Multi-Transient EM

49. Inversion model and response Offset 1500m

50. Inversion model and response Offset 3500m