METHOD OF MARINE ELECTRICAL EXPLORATION OF OIL AND GAS FIELDS AND SYSTEM OF EQUIPMENT FOR ITS IMPLEMENTATION Russian patent published in 2008 - IPC G01V3/06 G01V3/08 

FIELD: electric geological exploration.

SUBSTANCE: before submergence, clocks installed on the current dipole and the bottom stations are synchronized. The dipole is placed vertically, so that its upper end would be at a distance of no more than 200 metres from the sea surface, and the lower end would be no more than 100 m from the sea bottom (optimally, 20-30 m from the sea bottom). The dipole is excitated with alternating rectangular pulses. The bottom stations are used to record the sweep of the horizontal and vertical field components in time when the current is applied and when it is absent. During signal analysis, the change of primary and secondary fields in time is taken into account and data describing the medium resistance and its polarisation characteristics are determined. The system of equipment includes vessel with a generator and energising field generation unit, which are connected with a vertical dipole with current electrodes, submerged in water, and an onboard data recording and processing unit, using a cable. The system also includes set of bottom stations with horizontal and vertical electrodes and magnetic field sensors. The dipole and the bottom stations are equipped with clocks supporting synchronization.

EFFECT: possibility to obtain data about specific resistance and polarisability of strata during exploration of deep water areas, and provision of more accurate predictions.

3 cl, 1 tbl, 5 dwg