PATTERNS OF RESISTIVITY ARE DIRECT HYDROCARBON INDICATORS
The presence of hydrocarbons in rocks is also associated with characteristic resistivity patterns revealed
by MT - so-called "Direct Hydrocarbon Indicators" - as demonstrated by the international Project Paleorift
in Uzbekistan in 2002.
PROVEN DRILLING SUCCESS RATE OF
73% WITH IP
Certain mineral-fluid interfaces undergo a charge separation when an electric current is made to flow
through them, so the interface becomes polarized and a capacitance effect occurs. The Induced
Polarization (IP) method identifies anomalies by the characteristic phase lag between transmitted and
received signals caused by the capacitance. Using IP, China National Petroleum Corp. (CNPC) has achieved
a drilling success rate of 73% (based on 65 wells). Reservoir Mapping, Secondary Recovery Monitoring with
CSEM Controlled-Source Electromagnetics (CSEM) methods measuring polarization and resistivity have
proven successful in mapping hydrocarbon reservoirs. The intrusion of water and/or steam in secondary
recovery operations is evident from the resulting resistivity changes, as demonstrated recently by Brazil's
PETROBRAS.