PROCESS OF ELECTRIC PROSPECTING WHILE SEARCHING FOR OIL AND GAS FIELDS Russian patent published in 1999 - IPC

FIELD: conducting of geophysical prospecting of oil and gas fields by electromagnetic methods. SUBSTANCE: for increased authenticity of detection of pool, its depth and outline electric prospecting is conducted by multiple profiling by means of setting of soundings, field in points of observation of each setting is recorded in interval from t_e to t_f, where t_e is effective duration of pulse of formation of field which is found by point of crossing of tangent to curve of pulse of formation of field at moment of its dip with time axis, t_f is final recording time. Frequency analysis of signal recorded in midpoint of setting of soundings is carried out and root-mean-square level of harmonics of spectrum A_m in frequency interval from 20 to 40 Hz is found. Frequency analysis of part of signal selected in current time window is carried out and quasi-harmonic oscillations of low-frequency electromagnetic radiation of layer in frequency range from 1 to 10 Hz are isolated. Later value of average energy of spectrum in this frequency range is determined, it is normalized by value of A_m and increment of normalized energy of low-frequency electromagnetic radiation of layer is used to judge on availability of oil and gas field, to determine its outline and depth of occurrence. EFFECT: increased authenticity of detection of oil and gas field. 1 dwg