Direct Hydrocarbon Prospecting Using Electromagnetic Methods
, by Allan Snyder
In this report the electrical transient method for diret hydrocarbon detection is analyzed. The method uses a Schlumberger electrode arrangement with a pulsed square wave source, which was modeled in the present study using plane waves in a stratified medium. It is found that hydrocarbon-bearing rocks cannot be distinguished from background clastic or background massive carbonate rocks except at very shallow depths, unless the background rocks are extremely homogeneous. The method also cannot distinguish between hydrocarbon-bearing rocks and massive carbonates when they are modeled separately with clastic rocks as background. It appears that the electrical transient method may only be useful for hydrocarbon pools with extremely homogenous overlying rocks.