FIELD: physics.
SUBSTANCE: method is realised as follows. At the first step during movement of the geophysical vessel, generation, amplification and weakly directed emission of intense hydroacoustic waves in the frequency range from 1 Hz to 3000 Hz is performed. These waves propagate at a speed defined by elastic properties of the medium and its density and return while being partially absorbed, reflected and scattered. Simultaneously, continuous, weakly directed reception and amplification of the partially reflected and refracted low-frequency hydroacoustic waves is carried out and a low-frequency echo signal F'1 is obtained in the frequency range 1-3000 Hz. The geologic-geophysical profile is obtained as a result. On the first time interval of the second step of realising the disclosed method, the geophysical vessel moves on the heading on the designated profiles based on results obtained at the first step. Based on a given program, by combining emission and pause intervals, balanced emission of intense hydroacoustic waves at frequency F2 in a wide frequency band 1-10 Hz or at frequency F3 in a narrow frequency band 2.5-3.5 Hz is carried out. Simultaneously, generation and linear emission of two low-frequency hydroacoustic pumping signals are carried out at close frequencies ω1 and ω2, which interact with each other and are converted to sum and difference frequencies. The low-frequency wave of the difference signal Ωi=ω2-ω1 propagates at considerable distances at a speed defined by elastic properties of the medium and density thereof. Simultaneously, generation, amplification, conversion and directed emission of low-frequency hydroacoustic waves at frequency ω3 are carried out, through which a precipitation layer and a layer of sound scatterers over the hydrocarbon deposit are located. In the low-frequency receiving GAS, the low-frequency echo signal F'2 in a wide frequency band 1-10 Hz or the low-frequency echo signal F3 in a narrow frequency band 2.5-3.5 Hz are transmitted to the corresponding computer input and changes in the integral levels of the narrow and relatively wide frequency band are obtained. Simultaneously, reception, amplification, filtration and accumulation of corresponding low-frequency echo signals Ω'i are carried out in a linear channel for receiving low-frequency waves of the echo signals of the difference frequency wave; said signals are then transmitted tot he corresponding computer input. Simultaneously, reception and pre-amplification of high-frequency echo signals ω'3i is carried out in the linear channel for receiving high-frequency echo signals ω'3; highly directed reception and amplification of high-frequency acoustic modulation frequencies: ω4±Ωi and ω4±fi are carried out in the acoustic path channel for non-linear reception of low-frequency echo signals, and low-frequency useful signals are then extracted from the high-frequency acoustic modulation frequencies and then transmitted to the corresponding computer input; directed reception and amplification of high-frequency electromagnetic modulation frequencies: ω4±Ωi and ω4±fi are carried out in the electromagnetic path channel for non-linear reception of low-frequency echo signals, and low-frequency useful signals are then extracted therefrom and transmitted to the corresponding computer input; reception, amplification, filtration and integration of low-frequency useful signals Ωi and fi, which are then transmitted to the corresponding computer input, are carried out in the path for linear reception of low-frequency signals, where processing of all information is carried out and oil-and-gas content of hydrocarbon reservoirs on the hydrocarbon deposit is determined.
EFFECT: efficient, highly reliable search and recognition of hydrocarbon deposits on a large area with minimum financial and time expenses, while ensuring navigation safety of the vessel and environmental safety for marine life and the environment overall.
12 dwg
