METHOD FOR MARINE GEOELECTRICAL EXPLORATION (ALTERNATIVES) Russian patent published in 2004 - IPC

FIELD: geophysical research using adjustable man-made electromagnetic field sources.

SUBSTANCE: first of alternative methods includes excitation of electromagnetic field in mass of medium under research by sending two similar square current pulses thereto, one being sent during forward passage of sounding unit along research profile and other one, during its reverse passage. Second alternative method includes sending of one current pulse to medium under research when first three-point measuring unit crosses sounding point and other current pulse, when second unit does so. Third alternative method is characterized in that one sounding current pulse is sent to each sounding point. Instant value of first and second axial potential differences are measured throughout period of existence of transient signals by end of each current pulse and during pulse-to-pulse spaces. Two adjacent instant values of first and second potential differences are separated throughout entire length of each space and magnitudes of their differences are determined. Four sets of normalized electrical parameters are calculated from values of all above-listed differences and inverse problem is solved using parameters obtained and basing on mathematical physics differential equation for dipole source strength in electrochemically polarizing conducting medium. Model of medium closest in geometry and in electrical parameters to that under research is found. Time sections of this model are constructed using electrophysical parameters included in this equation such as electrical conductivity of medium elements, coefficient of their induced polarization, and time constant of induced-polarization potential difference drop.

EFFECT: enhanced precision of methods.

9 cl, 3 dwg