RU2433425C2 - Method for seismic prospecting hydrocarbons and method of determining attitude of producing formations on hydrocarbons and seismic station for realising said method - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: in contrast to existing methods, the disclosed engineering solution further involves recording tsunami wave pressure at the bottom at frequencies 0.003-0.01 Hz using ocean-bottom seismographs with 0.003-20 Hz wideband seismic channels; the picked up signals are transmitted over a hydroacoustic communication channel to drift buoys placed on the investigated points, picked up signals from which are transmitted over a satellite communication channel to reference points, wherein magnetic field variation is additionally measured at frequencies 0.01-1.0 Hz, magnetic induction of the electromagnetic field is measured at frequencies 1-200 Hz, the electric component of the electromagnetic field is measured at frequencies 1-500 Hz, acoustic noise is measured at frequencies 5-50000 Hz, seismic noise is measures at frequencies 0.01-20 Hz, hydrodynamic noise of the sea is measured at frequencies 0.01-100 Hz in tectonic zones; factorial analysis is performed based on the measured parameters at the level of natural geophysical background and geophysical background during the period when the sun and the moon are on one celestial line, by plotting a curve of the amplitude of gradients of seismic, geodeforamation, geochemical and hydrophysical factors based on measurement which do not exceed 50-100 km in middle latitudes and 8-10 km in high and equatorial latitudes respectively, while aligning the measuring apparatus on eight bearings; additionally, seismic noise is measured at frequencies 0.008-20 Hz at the water-ground boundary, wherein odd harmonics 0.003 and 0.005 Hz are picked up from the spectrum of horizontal components, and even harmonics 0.002, 0.004, 0.006 and 0.008 Hz are picked up from the spectrum of the vertical component, and the coastal seismic stations measure the tidal level; measuring devices are placed at observation depth horizons which are multiples of 20 m, with maximum observation horizon equal to 100 m, uniformly distributed on the azimuth; hydroacoustic signals are detected with picking up of phase types PP, S and T; the arrival of an acoustic wave of seismic origins is determined from the frequency shift value of the scattered radiation, wherein the recording devices placed away from the coastal zone perform analysis of low-frequency components of the scattered signal using ship navigation noise as reference quasi-harmonic high-frequency signals, and recording devices placed in the coastal zone determine the onset and direction of arrival of seismic waves via narrow-band filtration and spectral analysis of waves, phase types PP, S and T are picked up via narrow-band filtration using recursive Butterworth filters. Input filtration is carried out using recursive filters with integral coefficients, and signals with sampling frequency of 100 Hz or less are filtered with floating point number coefficients; hydroacoustic signals are picked up using wideband ocean-bottom seismographs with not less than three seismic channels. Signals are analysed using three independent detectors, and the detection signal is generated upon coincidence of signals from at least two of three channels; spectral analysis is performed for volume waves with phases PP and S, and for Love, Rayleigh and Stonely surface waves; plotting the map of amplitude variations of the microseismic signal for each spectral frequency of spatial variations, as well as associating each obtained map with its corresponding depth is carried out by approximating the profile of the vertical relief relative the coastal line. The basic spline used is a cubic spline with zero boundary derivatives, wherein construction of a two-dimensional spline-function is executed through tensor product of one-dimensional splines. The measurement base at the sea floor is formed by placing seismic receivers at a distance of not more than 5 km from each other to form an isosceles triangle in the underwater space, at the vertices of which seismic receivers are placed. Hydroacoustic antennae of the seismic receivers include four transceivers of acoustic signals mounted on a perforated arm with formation of two single-channel and one double-channel transceivers, the antennae of single-channel transceivers lying 1000 mm from each other in the frontal zones of the perforated arm. The double-channel transceiver is formed from two transceivers lying 50 mm from each other, one of which lies 200 mm from the first single-channel transceiver, and the second single-channel transceiver lies 800 mm from the second single-channel transceiver. The transceivers are arranged on the perforated arm to form two measurement bases having a common centre. Seismic vibration receivers are placed in the shelf zone, along the line of the foot of the continental slope and along the axis perpendicular to the Gardiner line on fault boundaries. The device additionally includes a methane sensor connected by its output to a recording and control unit, a coordinate-determining circuit connected by its input-output to the input-output of the recording and control unit, a block of wideband transducers in which wideband transducers are in form of a sealed cylindrical vessel divided by a partition wall into compartments filled with an electrically conducting liquid. The partition wall has a hole in the middle and on whose sides there are mesh electrodes. The butt-ends of the cylinder are in form of elastic membranes. The block of wideband transducers is connected by its input-output to the input-output of the recording and control unit. The block of highly sensitive seismic sensors comprises four transceivers of acoustic signals mounted on a perforated arm with formation of two single-channel and one double-channel transceivers, the antennae of single-channel transceivers lying 1000 mm from each other in the frontal zones of the perforated arm. The double-channel transceiver is formed from two transceivers lying 50 mm from each other, one of which lies 200 mm from the first single-channel transceiver, and the second single-channel transceiver lies 800 mm from the second single-channel transceiver. The transceivers are arranged on the perforated arm to form two measurement bases having a common centre. The housing of the mobile multichannel seismometric system is made from high-strength aluminium alloy with a protective coating in form of anodic oxidation with a multilayer paint coat.

EFFECT: fewer erroneously drilled wells, possibility of monitoring exploitation of production wells and gas storages during oil and gas extraction.

3 cl, 3 dwg

Description

The invention relates to the field of seismic research and can be applied when searching for hydrocarbon deposits on land and on the continental shelf.

Currently, almost all of the work related to the search for hydrocarbons is somehow related to seismic exploration. Traditionally, seismic exploration is the registration of the propagation of generated seismic vibrations in the earth's crust, followed by mathematical processing of the obtained data. Currently known seismic exploration techniques usually use registration of the passage of seismic vibrations with a frequency of more than 10.0 Hz. During the use of such frequencies in seismic exploration, hardware design for generating and recording such oscillations, as well as a mathematical apparatus for processing data, have been quite widely developed. Either vibrators or explosions are predominantly used to generate such vibrations. For blasting, it is necessary to drill holes for laying explosives. This technique sharply negatively affects the state of the environment in the search area. In addition, the success rate of prediction using known methods and techniques of seismic exploration does not exceed 0.5. Therefore, at least every second well drilled according to the conclusions of traditional seismic exploration of oil and gas deposits, is erroneously laid. In addition to funds spent in vain for drilling a well, irreparable and unreasonable damage to the environment is inflicted.

There is a method of vibro-seismic exploration when searching for a hydrocarbon deposit [1], in which seismic vibrations are excited by a vibrator, a seismic signal is recorded by three-component seismic receivers and mathematically processed, and seismic vibrations are excited in a frequency range of 2-5 Hz for at least 3 minutes, registration of seismic the signal is carried out for at least 20 minutes before the excitation of seismic vibrations and no more than 5 minutes after the end of the generation of seismic vibrations , the seismic background of the Earth is used as a seismic signal, and the presence of a deposit is judged by the increase in the area under the curve of the mutual spectrum of the same components when recording a seismic background after excitation of seismic vibrations compared with recording a signal before generating oscillations.

The disadvantage of this method is the low information content that does not allow to determine the depth of the deposit, as well as the complexity of the mathematical analysis of the received signals due to the inability to separate the recorded interference.

There is also a method of searching for hydrocarbon deposits [2], in which seismic vibrations are generated by a seismic vibrator in the range from 2 to 5 Hz, an information signal is recorded using three-component seismic oscillation receivers capable of recording an information signal in the infrasonic range and located at a distance of no more than 500 m from each other and no further than 500 m from the seismic vibrator, in the frequency range from 2 to 5 Hz simultaneously for three components both before and during the generation of the seismic signal, and the presence of hydrocarbon deposits is judged by the appearance of the spectral anomaly of the information signal on at least one of the components when recording the information signal during the generation of seismic vibrations compared with the information signal measured before generation.

The disadvantage of this method is the low information content that does not allow to determine the depth of the deposit, as well as the complexity of the mathematical analysis of the received signals due to the inability to separate the recorded interference.

A known method of seismic exploration [3], including the formation of zones of emission and reception of seismic signals, registration of an information signal, followed by mathematical processing of the obtained data, and the signal is recorded by at least two three-component seismic installations located at some distance from each other.

To implement this method, it is necessary to use seismic emitters and conduct a preliminary study of the geological section in the search area.

There is also a known method of seismic exploration when searching for oil and gas fields [4], based on determining the wavelength L of the predominant seismic background in an unpromising area, in which the correlation between the same components is weakened by more than two times. In the area under study, at least two three-component installations are located at a distance L / 4. The natural seismic background is recorded for all components at frequencies of 1-20 Hz. The presence of a field is judged by the shift towards low frequencies of the maximum frequency spectrum of the seismic signal recorded in the study area.

However, this method is time-consuming due to the need to carry out seismic studies on a prospectless field, which requires preliminary work to identify such a site, and then perform seismic studies on a promising field, which can be detected by comparing the recorded signals over both sites. At the same time, obtaining objective estimates of research results is possible only with synchronous registration of signals over both sections.

There is also known a method of seismic exploration in the search for groundwater [5]. The specified method consists in placing at least three electric probes in the Earth in separate positions in a straight line, passing through the studied area of the Earth between the first and second electric current probes and measuring the potential difference between the first and third probes, as well as between the third and second a probe. The indicated potential differences are compared with each other, and the presence of groundwater is determined based on such a comparison.

This method is also time-consuming due to the need to perform drilling operations necessary for the equipment of the mines for the placement of electric probes, and allows you to achieve the required degree of reliability of determining the site with a promising field, provided that a significant number of mines for the placement of electric probes are equipped.

There is also a known method of seismic exploration in the search for groundwater [6], which is aimed at expanding the scope of use of the seismic exploration method by ensuring the detection of groundwater (artesian basins) using the same means.

To solve the problem, in this method of seismic exploration, which includes recording the natural seismic background and the seismic signal in the studied space, measured by one or more seismic complexes, followed by mathematical processing of the measured values, which are used to judge the presence of groundwater (artesian basins) in the studied space, the presence of groundwater (artesian pools) is judged by a significant (5-10 times) increase in the level of seismic background in the frequency range 4-15 Hz in relation to the level of natural seismic background in the control areas with a guaranteed absence of groundwater (artesian basins) and the presence of resonant peak values of the background level at frequencies of 5-13 Hz.

Moreover, the essence of the method is as follows.

Previously, the spectral characteristics of the Earth's natural seismic background using seismic complexes are determined on an area located near the groundwater (artesian basin) search site and having a similar geological section, and they are recorded. Then one or more seismic complexes are located in the area of groundwater search (artesian basins) and the seismic background is recorded in the frequency range 1-20 Hz.

Repeat the registration of seismic background at other points above the location of the alleged location of groundwater (artesian basins).

The seismic background is recorded within 30-60 minutes.

The presence of groundwater (artesian basins) is judged by a significant (5-10 times) increase in the overall level of seismic background in the space under study and the presence of resonant peak values of the amplitudes of the seismic background at frequencies of 5-13 Hz.

The characteristic shape of the signal in the measured dynamic range, its excess over the background (5-10 times), the presence of peak values make it possible to use single-component or two-component seismic complexes oriented along the respective axes for groundwater detection (artesian basins), followed by mathematical processing of the obtained data .

This method is also time-consuming due to the need to perform preliminary work and is burdened by significant mathematical processing.

There is also a method of searching for hydrocarbons (options) and a method for determining the depth of productive formations [7], in which the technical task to be solved is to increase the accuracy of determining productive hydrocarbons in formations, including determining the depth of their occurrence.

The technical result obtained as a result of the implementation of the method consists in reducing the number of erroneously drilled wells, as well as providing the ability to control the operation of production wells and gas storages during oil and gas production.

To achieve the indicated technical result according to the first embodiment, it is proposed to use a hydrocarbon search method characterized by recording seismic vibrations of the Earth’s surface using seismic vibrations receivers capable of detecting seismic vibrations in the range from 0.1 to 20 Hz, and seismic vibration receivers located at a distance of 50 to 500 m from each other, registration is carried out simultaneously for all measured components, dividing the time range of registration of the measured into the prospective area of the information signal for discrete sections synchronized in time for all seismic receivers, calculate the spectral characteristics corresponding to each discrete section with the formation of a discrete sequence, analyze each discrete section for the presence of interference of anthropogenic nature, and for the presence of an event associated with the arrival of the signal from the reservoir, those discrete sections that do not contain events associated with Odom signal from the producing formation in each of the entries corresponding components of seismic receivers, and discrete regions containing said interference, and analyzed with the remaining discrete areas of judging the presence or absence of hydrocarbons. When implementing the method, seismic oscillations are additionally measured in a place that is obviously not containing hydrocarbons, and the presence of oil or gas is judged by the appearance of deviations in the spectral characteristics, compared with a place that is obviously not containing hydrocarbons. The method can be implemented both on land and in the water area, with seismic receivers respectively being located on land, in the bottom of the water area, or deepened in the surface layer, in the aquatic environment, and / or on watercraft in places minimally prone to natural vibrations of the body of the craft moreover, the watercraft are removed at equal distances from the source of oscillation generation.

According to the second variant of achieving the indicated technical result, it is proposed to use a hydrocarbon search method characterized by recording seismic vibrations of the Earth’s surface using seismic oscillation receivers capable of detecting seismic vibrations in the range from 0.1 to 20 Hz, and seismic oscillations are generated by the oscillation source in the range from 1 up to 10 Hz, receivers of seismic vibrations are located at a distance of 50 to 500 m from each other and from 50 to 500 m from this source cosmic vibrations, the registration of the information signal is carried out in frequencies from 0.1 to 20 Hz for all measured components both during the generation of vibrations, and also after the generation of seismic vibrations, dividing the time range of registration of the information signal measured on the prospective area into discrete sections, the spectral characteristic is calculated corresponding to each discrete section with the formation of a discrete sequence, analyze each discrete section for interference, having technogenic nature, and the presence of an event associated with the arrival of a signal from the reservoir, those discrete sections that do not contain events associated with the arrival of a signal from the reservoir in each of the records of the corresponding components of seismic receivers, as well as discrete sections, are excluded from further consideration containing these interference, and analyze the remaining discrete sections with a judgment on the presence or absence of hydrocarbons. In a preferred embodiment, the Earth’s microseismic noise is additionally measured and the presence of hydrocarbons is judged by the appearance of changes in the spectral characteristics of at least one of the components when recording a signal during oscillation generation and / or after oscillation generation compared to the information signal measured before generation. The proposed method can also be implemented both on land and in the water area; therefore, seismic receivers are located on land, in the bottom of the water area and / or on watercraft in places that are minimally prone to natural vibrations of the body of the craft, and the craft are removed at equal distances from the source of oscillation generation. In all cases of the implementation of the proposed method, usually the receivers of seismic vibrations are grouped and also synchronized. In addition, in the process of mathematical processing of the recorded results, the information signal is mainly divided into temporary sections of at least 2-3 signal periods of the lowest frequency range.

The indicated technical result is also achieved by using a method for determining the depth of productive strata, including the placement of at least four receivers of seismic vibrations capable of detecting vibrations in the infrasonic frequency range, and recording an information signal, while the Earth uses microseismic noise as an information signal, moreover, a pre-identified focus of microseismic activity of the oil and gas field is placed at the peaks mainly but of a convex quadrangle, seismic receivers capable of detecting both vertical and horizontal infra-low-frequency seismic vibrations for a period of time sufficient to record a statistically significant noise signal in the infra-low-frequency range generated by the oil and gas field, generate seismic vibrations by a vibration source in the range from 1 to 10 Hz, calculate the spectral density of the vertical, horizontal components, as well as the spectral density These cross-correlation functions of the recorded infra-low-frequency oscillations, then, solving the inverse wave problem of the propagation of acoustic radiation from a cylindrically symmetric source, determine the depth of the reservoir productive to hydrocarbons.

To ensure the search for hydrocarbons on land, the following is proposed according to the so-called first embodiment. At least one seismic vibration detector capable of detecting vibrations in the infrasonic frequency range of at least one component is located above the prospective deposit, and the spectral characteristic of the Earth’s microseismic noise at frequencies from 0.1 to 20 Hz is calculated simultaneously by all the receivers used. for all measured components. Preferably, the registration is repeated at other points above the intended location of hydrocarbons. The presence of deposits is judged by the change in the spectral characteristics of the information signal or their various combinations, allowing to reduce the influence of interference. In the context of the present invention, the term “spectral characteristics” means functions or a combination thereof obtained by spectral analysis of an information signal, wherein said spectral analysis may include both Fourier analysis (Fourier transform, Wavelet analysis) and decomposition of the information signal into a series converging only asymptotically. In the context of this work, an information signal is understood to mean a measured microseismic oscillation signal that has undergone mathematical processing in accordance with a number of algorithms, in particular, those given below for clearing interference and isolating the signal emitted by the reservoir. For example, the spectral power of the measured signals and / or cross-correlation, or combinations thereof, to reduce interference can be selected as the spectral characteristic. In particular, the presence of deposits is judged by the change in the spectral power of the information signal at the measured frequencies, by the increase in the correlation of the information signal of the same name components (at least one) at different observation points relative to the information signal for a site that is obviously free of hydrocarbons.

When searching for hydrocarbons in the water area according to the considered option, at least one receiver of seismic vibrations, capable of detecting infrasonic vibrations by at least one component, is placed either at the bottom of the water area, or, being buried, in the aquatic environment, or on board mainly self-propelled watercraft and measure microseismic Earth noise simultaneously for all measured components. If the receiver of seismic vibrations is placed on board the craft, the least noisy places of the craft should be chosen in the informative frequency range. Mostly registration is carried out for at least 30 minutes. The receivers are placed at the bottom of the water area (on board the boats, diving into the aquatic environment), grouping, at a distance of about 50-500 m from each other. In this case, the registration point is usually located on the surface of the water at approximately equal distance from all used receivers of seismic vibrations.

When searching for a hydrocarbon deposit on land in the second embodiment, acoustic oscillation receivers are located above the location of the alleged hydrocarbon location, capable of detecting infrasonic vibrations in at least one of the components similar to the first variant, but additionally generate seismic vibrations by a source of seismic vibrations in the range from 1 to 10 Hz. The sensors are located from 50 to 500 m from the source of seismic vibrations, record the earth's seismic background for preferably 20 minutes, turn on the source of seismic vibrations and, without stopping the recording of the Earth's microseismic noise, generate seismic vibrations for about 3 minutes. The recording of microseismic noise of the Earth can be continued even after the generation of oscillations ceases.

Processing of the measured seismic vibrations occurs similarly to the first option, however, the presence of deposits can also be judged by the appearance of changes in the spectral characteristics of at least one of the components when recording a signal during oscillation generation and / or after oscillation generation compared to the information signal measured before generation or from the analysis of the spectral characteristics of discrete sections of microseismic noise of the Earth during / after the action of the vibrator. An important stage in the placement of seismic receivers in all cases of measuring oscillations is their grouping, which allows for further signal processing to reduce the influence of noise and apply algorithms for extracting the information signal.

When searching for hydrocarbons in the water area according to the second option, the receivers of seismic vibrations are placed similarly to the first. The rest of the measurements are carried out similarly to measurements on land in the second embodiment.

As part of the implementation of the first and second options, the task of controlling the operation of a hydrocarbon deposit can be solved. To do this, control points are selected over the reservoir, preferably located near production wells. At selected points, receivers of seismic vibrations are located, capable of detecting seismic vibrations in the infrasonic frequency range of at least one of the components. The microseismic noise of the Earth is periodically recorded. By the disappearance of the anomaly of spectral characteristics at frequencies of 0.1-20 Hz, the passage of the water-hydrocarbon contact under the control point is judged.

The anomalous behavior of the spectral characteristics is determined by any of the above options - without applying external influences, by analyzing the behavior of the spectral characteristics of each discrete section of the time range partition, or with respect to the spectral characteristic of the information signal recorded for the section that obviously does not lie above the reservoir, as well as in the variant using external influence, using the same oscillation processing algorithms, but applying them to the recorded signal during / after air The action of the source of seismic vibrations, or the transition of the water-hydrocarbon contact, is judged by the appearance of changes in the spectral characteristics of at least one of the components when recording a signal during oscillation generation and / or after oscillation generation compared to the spectral characteristics of the information signal measured before generation. It is preferable to record the spectral characteristics of the microseismic noise of the Earth for each point for 40-60 minutes.

When controlling the degree of filling of the underground natural gas storage, points on the Earth's surface are selected that roughly determine the different degrees of filling of the gas storage, seismic vibration detectors are placed at selected points that are capable of recording infrasonic vibrations by at least one component, and the spectral characteristics of the Earth’s microseismic noise are periodically recorded, moreover the absence of an abnormal change in the spectral characteristics of the information signal at frequencies of 0.1-20 Hz stvuet the absence of natural gas under the control point. For comparison, a microseismic noise of the Earth is recorded by a similar receiver above a place obviously located outside the gas storage. It is preferable to select control points during the first filling of the gas storage, determining in which places above the gas storage the presence of natural gas is noted at various amounts of supplied gas. However, in any case, control points are determined empirically. It is possible to generate seismic vibrations during the registration process. In this case, registration is carried out both before the start of generation and during generation.

Using, in particular, the second option (with generation), it is possible to determine the depth of the reservoir productive for hydrocarbons. To do this, use at least 4 receivers of seismic vibrations, capable of detecting infrasound vibrations by 3 mutually perpendicular components, placing them at the vertices of the quadrangle.

In all of the above embodiments of the invention, a fundamental and important step is the filtering process of the recorded time series from surface noise and the selection of the information signal. For this purpose, a grouping (arrangement) of seismic oscillation receivers and cross-correlation processing of the recorded signal are used.

To implement the above options, a seismic oscillation receiver can be used, capable of detecting vibrations in the infrasonic range, containing at least one seismic oscillation sensor capable of detecting infrasound vibrations, all the sensors used are located on a rigid base so that the sensitivity axes of the sensors are located at fixed angles relatively flat rigid base and relative to each other, with each sensor connected to the regis unit radio and the base with the sensors placed in the rigid sealed housing. Angular and / or linear vibration sensors capable of detecting vibrations in the infrasonic frequency range can be used. Advantageously, the recording unit of each sensor comprises a pre-connected signal amplifier, an amplitude-frequency response driver and a terminal amplifier, each terminal amplifier being configured to be connected to a common recorder.

The use of the invention will improve the accuracy and reliability of determining the presence of hydrocarbon deposits.

However, the known method [7] is based on the hypothesis of an oil deposit as the only possible source of the observed anomaly in the low-frequency range of the seismic spectrum. At the same time, practice shows [8] that anomalous signals are observed in the presence of other significant heterogeneities in the section, in particular in the form of active tectonic disturbances or in the presence of underground rivers. An abnormal signal is also observed in the target range with a shallow basement at the point of study, commensurate with the depth of hydrocarbons.

In addition, when placing seismic oscillation receivers on boats or at deep horizons, it is necessary to exclude from the observation results the signal component due to noise of navigation and the speed of underwater currents.

In the known method of low-frequency seismic sounding for the search and exploration of hydrocarbon deposits (options) [8], the problem is solved by the method of low-frequency seismic sounding for the search and exploration of hydrocarbon deposits, including the determination of at least one observation point in the search area, placement at the observation point of the receiver seismic vibrations, registration of information signals by their measured components for a period of time sufficient to record statistically significant a noise signal in the infra-low-frequency range, calculating the spectral characteristics using the Fourier transform of the received signals, analyzing them for the presence of false signals and signals from the reservoir with natural hydrocarbons, excluding false signals from the analysis, analyzing the remaining signals with a judgment on the presence or the absence of hydrocarbons, in which, unlike the known method, registration and recording are carried out on the vertical components of information signals, Fu rye conversion of the vertical components of information signals is carried out according to their first derivative, the maximum is determined on the obtained spectra, which is characterized by the location on the spectrum in the frequency range

Vs / H <F <Vp / H,

where Vs is the average sedimentary cover velocity of transverse seismic waves at the observation point;

Vp - average sedimentary cover velocity of propagation of longitudinal seismic waves at the observation point;

H is the known basement depth at the observation point,

a signal with this maximum is taken as a false signal corresponding to the resonance between the day surface and the foundation — a signal from the foundation, a point with a spectrum that contains a signal from the foundation with a monotonic decrease in the spectrum amplitude towards high frequencies from the maximum of the signal from the foundation is recognized as a hopeless observation point observations, in the signal spectra of which there are maxima at frequencies greater than the frequency of the maximum signal from the foundation, with their uniform arrangement with an offset relative to other measurements less than half the width of its maximum, is taken as promising for the presence of hydrocarbons from natural reservoirs. In this case, when identifying a uniform arrangement of signals, it is possible to compare them relative to signals of other measurements from one observation point, or relative to signals from other channels of their recording from this observation point with a multi-channel observation method, or relative to signals from their recordings from neighboring observation points with a single-channel observation method. If there are more observation points in the study area, the signal from the foundation additionally characterizes its presence at most observation points.

The problem is also solved by the second variant of the method of low-frequency seismic sounding for the search and exploration of hydrocarbon deposits [8], which includes determining at least one observation point on the search area, placing seismic vibrations at the observation point of the receiver, recording information signals from their measured components in for a period of time sufficient to record a statistically significant noise signal in the infra-low-frequency range, the calculation of the spectral characteristics Using the Fourier transform of the received signals, analyzing it for the presence of false signals and signals from the reservoir with natural hydrocarbons, excluding false signals from the analysis, analyzing the remaining signals with a judgment on the presence or absence of hydrocarbons, which, unlike the known method registration and recording are carried out on the vertical components of information signals, the Fourier transform of the vertical components of information signals is carried out according to their first water, on the obtained spectra reveal the maximum, which is characterized by the location on the spectrum in the frequency range

Vs / H <F <Vp / H,

where Vs is the average sedimentary cover velocity of transverse seismic waves at the observation point;

Vp - average sedimentary cover velocity of propagation of longitudinal seismic waves at the observation point;

H is the known depth of the foundation at the observation point,

a signal with this maximum is taken as a false signal corresponding to the resonance between the day surface and the foundation — the signal from the foundation, the point with the spectrum, in which there is a signal from the foundation with a monotonic decrease in the spectrum amplitude towards large frequencies from the maximum of the signal from the foundation, is recognized as a hopeless observation point spectra of signals in which there are maxima at frequencies greater than the frequency of the maximum signal from the foundation, these spectra are classified into two groups: 1) spectra with equal by the uneven arrangement of signal maxima with an offset of relative to other measurements by less than half the width of their maximum, 2) spectra with an uneven arrangement of signal maximums with an offset of other measurements by at least half the width of their maximum; the observation point with signals with a spectrum of the first group is defined as promising for the presence of deposits from natural hydrocarbons, signals with a spectrum of the second group are defined as false signals - signals from the zone of possible tectonic disturbances. In this case, when identifying a uniform or uneven arrangement of signals, it is possible to compare them relative to signals of other measurements from one observation point, or relative to signals from other channels of their recording from this observation point with a multi-channel observation method, or relative to signals from their recordings from neighboring observation points with a single-channel observation method observations. If there are more observation points in the study area, the signal from the foundation additionally characterizes its presence at most observation points.

This method allows you to distinguish between false signals from signals from the reservoir and thereby dramatically increase the reliability of decisions. The registration and recording of signals is carried out in a wide frequency range of 0.5-50 Hz, corresponding to the range of the depths of the foundation.

Search and reconnaissance methods are implemented using well-known hardware, for example, using the Express-4 mobile digital seismometric complex developed by the Geofizpribor Design Bureau of the Russian Academy of Sciences (Moscow). The block diagram of a mobile multi-channel seismometric complex includes the following main modules:

- a set of highly sensitive seismic sensors of the type SM-ZKV ADNR;

- remote distributor with cable communication lines;

- a recording module with a block of filters and amplifiers, a board of analog-to-digital converters, digital-to-analog converters, a computer;

- GPS-receiver GARMIN 12 XL;

- Power Supply;

- calibration block.

The sensors are magnetoelectric pendulum geophones that convert the speed of mechanical vibrations into electric current, while the voltage excited at the ends of the receiver’s working winding is proportional to the speed of the soil. The recording module of the Express-4 complex provides reception of seismic signals, their conversion to digital code, registration of data in various formats, binding of recorded data to a single time, visualization of input data, calibration of seismic channels, preliminary assessment of the quality of recorded data. When processing and analyzing signals and their spectral characteristics, standard software tools such as Mathlab version 6.0 and higher are used.

For specific studies and field tests, three seismic receivers were used - a set of highly sensitive seismic sensors of the SM-ZKV type ADNR of the Express-4 mobile digital seismometric complex with 4 recording channels located at a distance of 50-100 meters from each other, in the frequency range 0 5-50 Hz, corresponding to a foundation depth of 6-8 km, seismic signals were recorded simultaneously for all recording channels for at least 400 seconds, as a result of signal reception and processing, Spectral characteristics including spurious signals from the foundation, the signals from disturbances, the signal from the producing formation.

The disadvantage of this method is the relatively low reliability, because to generate a signal in the range of 0.5-1.0 Hz by means of three seismic receivers of the same type, with the same measuring base, is a difficult technical task, especially in marine conditions.

There is also a known method of seismic exploration, which includes recording the natural seismic background from three components with at least two seismic receivers before and after generating seismic vibrations with a frequency of 0.1-70 Hz, judging the presence of oil and gas fields by increasing the area under the curve of the spectrum of seismic background for all three components after the generation of seismic vibrations [9].

The disadvantage of this method is the low reliability and reliability, because to generate a signal in the range of 0.1-1 Hz by means of two seismic receivers of the same type, with the same measuring base, is a difficult technical task.

The known method [10] solves the technical problem of increasing the efficiency of seismic exploration for great depths. The technical result is to increase the depth of seismic exploration while increasing the reliability and efficiency of seismic exploration at various depths through the use of the entire frequency range of the microseismic signal, including ultra-low frequencies.

In this case, the technical result is achieved due to the fact that in the seismic survey method, which includes preliminary determination of the dispersion curve of microseismic waves characteristic of the study area by synchronously recording microseismic signals with at least three seismic stations with vertical seismic sensors with subsequent evaluation of the apparent velocity dependences based on the obtained data the propagation of microseismic waves from the signal frequency, the determination of wavelengths and the frequency range based on e analysis of apparent velocities, in which the microseismic signal consists of Rayleigh waves, placing seismic sensors in the study area so that the distance between them is no more than half the shortest Rayleigh wavelength, determining the amplitude non-identity of the measuring channels of the seismic sensors in the microseismic signal frequency band by simultaneously recording microseismic signal by all seismic sensors at one point for a time sufficient to establish the stationarity of the spectrum the power of the microseismic signal, with the subsequent determination of the logarithmic difference of the spectra of all measuring channels of the seismic sensors, the registration of the microseismic signal by at least two seismic stations, one of which is installed stationary in the central part of the study area, and the rest move across the study area, accumulation of the power spectrum of the microseismic signal at each point measurements for a time sufficient to establish the stationarity of the spectrum, the calculation of the spectrum of spaces variations of the microseismic signal for each measurement point by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal stored at the seismic station installed stationary for an equivalent time in the same time period, taking into account the amplitude non-identity of the measuring channels of the seismic sensors, map amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, the binding of each gender scientific map corresponding to its depth H according to the ratio:

H = λ _p K

where K is the experimentally established numerical coefficient depending on the constituent rocks,

λ _p - Rayleigh wavelength, determined by the dispersion curve, m

The distinguishing features of the known method is the determination of the dispersion curve of microseismic waves with the subsequent assessment of the dependence of the apparent propagation velocities of microseismic waves on the signal frequency, the determination of wavelengths and the frequency range consisting of Rayleigh waves, the placement of seismic sensors by the above method, the determination of the amplitude non-identity of the measuring channels of seismic sensors with the subsequent determination of the logarithmic difference of spectra, registration of a microseismic signal stations, one of which is stationary, the accumulation of the power spectrum of the microseismic signal until the spectrum is stationary, the calculation of the spectrum of spatial variations of the microseismic signal for each measurement point, the construction of a map of the amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, the binding of each received map to its corresponding depth according to the above ratio, which allows to increase the depth of seismic exploration while increasing The reliability and effectiveness of seismic exploration at various depths through the use of the entire frequency range of the microseismic signal, including ultra-low frequencies. Microseismic signals are represented in the general case by the sum of body and surface waves of the Love and Rayleigh type. Moreover, the energy of surface waves in a microseismic signal is much higher than the energy of body waves and are not taken into account when implementing the method. The use of vertical sensors makes it possible to isolate only Rayleigh waves from the surface waves that contain the zero mode even in the absence of bright reflecting boundaries, in contrast to Love waves. Placing seismic sensors at a distance of no more than half the shortest Rayleigh wavelength allows you to achieve maximum horizontal resolution of the method. Taking into account the amplitude non-identity of the measuring channels of seismic sensors allows you to exclude the individual characteristics of the measuring channels when building maps. The accumulation of the power spectrum of the microseismic signal at each measurement point before establishing the stationarity of the spectrum must be done due to the duality of the nature of the microseismic signal, which consists of deterministic trains with random initial phases, random frequencies, amplitudes and directions of arrival. At sufficiently large times, these deterministic trains are a random stationary signal. It is these stationary characteristics, including the power spectrum, that are determined during measurements. The calculation of the spectrum of spatial variations of the microseismic signal for each measurement point is necessary in order to exclude the influence of sources forming the microseismic signal. The mapping of amplitude variations of the microseismic signal and their binding to the depth are made to obtain the mechanical characteristics of the medium at various depths.

The known method of seismic exploration [10] is as follows. The dispersion curve of microseismic waves characteristic of the study area is preliminarily determined by performing synchronous registration of microseismic signals by at least three seismic stations with vertical seismic sensors, followed by an assessment of the dependence of the apparent propagation velocity of microseismic waves on the signal frequency. The wavelengths and frequency range of the microseismic signal are determined based on an analysis of the apparent velocities in which it consists of Rayleigh waves. Seismic sensors are placed in the study area so that the distance between them is no more than half the shortest Rayleigh wavelength. Then, the amplitude non-identity of the measuring channels of the seismic sensors in the microseismic signal frequency band is determined by simultaneously recording the microseismic signal by all seismic sensors at one point for a time sufficient to establish the stationarity of the power spectrum of the microseismic signal, followed by determining the logarithmic difference of the spectra of all the measuring channels of the seismic sensors. A microseismic signal is recorded by at least two seismic stations, one of which is installed stationary in the central part of the study area, and the rest move around the study area. The power spectrum of the microseismic signal is accumulated at each measurement point for a time sufficient to establish the stationarity of the spectrum. The spectrum of spatial variations of the microseismic signal for each measurement point is calculated by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal accumulated at a seismic station installed stationary for an equivalent time in the same time period, taking into account the amplitude non-identity of the measuring channels of seismic sensors . Maps of amplitude variations of the microseismic signal are constructed for each frequency of the spectrum of spatial variations. Make a binding of each received card corresponding to its depth.

The value of the coefficient K is established experimentally in the course of mathematical modeling on the basis of the finite element method for the propagation of Rayleigh waves in an inhomogeneous half-space composed of rocks close to rocks of volcanic origin.

Using the proposed method of seismic exploration allows to increase the reliability of seismic exploration, provides a fundamental opportunity to conduct seismic surveys in places inaccessible to the use of artificial sources, allows seismic exploration at great depths, allows seismic exploration in monitoring mode without using sources. The method is technically simple to implement, environmentally friendly, cost effective.

However, the determination of the value of the coefficient K from experimental data, by mathematical modeling, is carried out on the assumption that the value of the coefficient K corresponds to the value of the coefficient in an inhomogeneous space composed of rocks close to rocks of volcanic origin. If the rocks of the heterogeneous space are composed of rocks of non-volcanic origin, then the value of the coefficient will be different from the accepted one, which will entail a significant error in the final research results.

In addition, when constructing maps of the amplitude variations of the microseismic signal, the triangulation method is used, when applying which the results of calculating differentials of various orders are not reliable.

The objective of the proposed technical solution is to increase the reliability of seismic studies in the search and exploration of hydrocarbon deposits.

The problem is solved due to the fact that in the method of seismic exploration, which includes recording the natural seismic background and seismic signal in the studied space, measured by one or more seismic complexes, followed by mathematical processing of the measured values, preliminary determination of the dispersion curve of microseismic waves characteristic of the study area, by conducting synchronous registration of microseismic signals by at least three seismic stations with vertical seismic sensors, followed by evaluation of the dependence of the apparent propagation velocities of microseismic waves on the signal frequency, determining wavelengths and the frequency range based on the analysis of apparent velocities, in which the microseismic signal consists of Rayleigh waves, placing seismic sensors in the study area so that the distance between them was no more than half of the shortest Rayleigh wavelength, the determination of the amplitude non-identity of the measuring channels of seismic sensors in the microseismic signal frequency band by simultaneously registering the microseismic signal with all seismic sensors at one point for a time sufficient to establish the stationarity of the power spectrum of the microseismic signal, followed by determining the logarithmic difference of the spectra of all measuring channels of the seismic sensors, accumulating the power spectrum of the microseismic signal at each point measurements for a time sufficient to establish the stationarity of the spectrum, even spectrum of spatial variations of the microseismic signal for each measurement point by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal accumulated at a stationary seismic station for an equivalent time in the same time period, taking into account the amplitude non-identity of the measuring channels of seismic sensors , mapping of amplitude variations of a microseismic signal for each frequency of the spatial spectrum x variations, binding each of the resultant s corresponding depth map; at the same time, information signals are recorded by their measured components for a period of time sufficient to record a statistically reliable noise signal in the infra-low-frequency range, spectral characteristics are calculated using the Fourier transform of the received signals, and they are analyzed for the presence of false signals and signals from the reservoir with natural hydrocarbons, false signals are excluded from consideration, an analysis of the remaining signals is carried out with a judgment on the presence of whether there are no hydrocarbons, registration and recording are carried out on the vertical components of the information signals in the frequency range 0.5-50 Hz, corresponding to the range of the basement depths, the Fourier transform of the components of the information signals is carried out according to their first derivative, the maximum that is taken as a false signal corresponding to the resonance between the day surface and the foundation - a signal from the foundation, the point with the spectrum at which the presence there is a signal from the foundation with a monotonic decrease in the amplitude of the spectrum towards higher frequencies from the maximum of the signal from the foundation, an observation point in the signal spectra of which there are maxima at frequencies greater than the frequency of the maximum of the signal from the foundation, with their offset relative to other measurements by less than half its width maximum, taken as promising for the presence of deposits from natural hydrocarbons, the presence of hydrocarbons is judged by the change in the spectral power of the information signal at the measured frequency In contrast to the known methods, the pressure of the tsunami waves to the bottom is additionally recorded at frequencies of 0.003-0.01 Hz using bottom seismographs with broadband seismic channels of 0.003-20 Hz, the recorded signals are transmitted via the hydroacoustic communication channel to drift stations located in the studied points registered signals from which are transmitted to reference points via a satellite communication channel, while additionally measuring magnetic field variations at frequencies of 0.01-1.0 Hz, magnetic induction is an electromagnet field at frequencies of 1-200 Hz, the electrical component of the electromagnetic field at frequencies of 1-500 Hz, acoustic noise at frequencies of 5-50000 Hz, seismic noise at frequencies of 0.01-20 Hz, hydrodynamic noise of the sea at frequencies of 0.01-100 Hz in the zones of tectonic faults, according to the measured parameters, they perform factor analysis at the levels of the natural geophysical background and geophysical background during the phase of the sun and moon being on the same sky line by plotting the amplitudes of the seismic, geodeformation, geochemical, and hydrophysical gradients iCal indicators at the base of measurements not exceeding 50-100 km in mid-latitudes and 8-10 kilometers high and equatorial latitudes, respectively, with an orientation measurement means eight rhumbs; seismic noise is additionally recorded at frequencies of 0.008-20 Hz at the water-ground boundary, while odd harmonics of 0.003 and 0.005 Hz are isolated from the spectrum of horizontal components, and even harmonics of 0.002, 0.004, 0.006 and 0.008 Hz are isolated from the spectrum of the vertical component, and at coastal seismic stations measure the level of the tide; registration devices are placed at deep observation horizons that are multiples of 25 m, with a maximum observation horizon of 100 m uniformly distributed in azimuth, hydroacoustic signals are recorded with phases such as PP, Z and T, the arrival of an acoustic wave of seismic origin is determined by the magnitude of the frequency shift scattered radiation, while using registration devices located at a distance from the coastal zone, they analyze the low-frequency components of the scattered signal using A set of reference quasiharmonic high-frequency signals of shipping noise, and using registration devices located in the coastal zone, determine the moment of arrival and direction of arrival of seismic waves by narrow-band filtering and spectral analysis of waves, phases like PP, S and T are selected by narrow-band filtering using recursive Butterfort filters while the input filtering is carried out by means of recursive filters with integer coefficients, and signals with a sampling frequency of 100 q and below are subjected to filtering with coefficients in a floating-point numbers; registration of hydroacoustic signals is carried out by means of broadband bottom seismographs with at least three seismic channels, while the signals are analyzed by three independent detectors, and the detection signal is generated when the signals coincide in at least two of the three channels; Spectral analysis is performed both of the body waves of the PP and S phases, and of the Love, Rayleigh, and Stoneley surface waves, the construction of a map of the amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, and also the binding of each received map to its corresponding depth by approximating the profile of the relief along the section relative to the coastline, and as the base spline, a cubic spline with zero boundary derivatives is used, while the construction of a two-dimensional spline function is performed by em-dimensional tensor product spline; in a method for determining the depth of hydrocarbon-productive formations, including the placement of at least four receivers of seismic vibrations capable of detecting vibrations in the infrasonic frequency range, and recording an information signal, using the Earth's microseismic noise as an information signal above a previously identified focus of microseismic activity of oil and gas deposits are placed at the vertices of the quadrangle seismic receivers, capable of recording as in vertical and horizontal infra-low-frequency seismic vibrations, for a period of time sufficient to record a statistically significant noise signal in the infra-low-frequency range, generated by the oil and gas field, seismic vibrations are generated by a vibration source in the range from 1 to 10 Hz, spectral densities of vertical, horizontal components are calculated , as well as spectral densities of cross-correlation functions of recorded infra-low-frequency oscillations, for we, solving the inverse wave problem of the propagation of acoustic radiation from a cylindrically symmetric source, determine the depth of the reservoir, in contrast to the known methods, form the measuring base on the seabed by placing seismic receivers at a distance of no more than 5 km from each other, with the formation of an isosceles triangle in the underwater space at the top of which seismic receivers are located, while the hydroacoustic antennas of seismic receivers include four receivers acoustic signal transmitter mounted on a perforated bracket, with the formation of two single-channel and one two-channel transceivers, with the placement of antennas of single-channel transceivers at a distance of 1000 mm from each other in the end zones of the perforated bracket, while the two-channel transceiver is formed of two transceivers spaced at a distance of 50 mm from each other, one of which is located at a distance of 200 mm from the first single-channel transceiver, and the second single-channel receiver eredatchik located at a distance of 800 mm from the second one-channel transceiver, the transceivers are located on the perforated bracket to form two measuring bases, having a common center; seismic oscillation receivers are placed in the shelf zone, along the foot of the continental slope and along an axis perpendicular to the Gardiner line along the fault boundaries, and in a seismic receiver, including a mobile multi-channel seismometric complex, consisting of a block of highly sensitive seismic sensors, a remote distributor with cable communication lines, recording a module with a block of filters and amplifiers, boards of analog-to-digital converters, digital-to-analog converters, a computer, a GPS receiver, power supply, calibration unit, processing unit, analysis of signals and their spectral characteristics, software such as Mathlab version 6.0 and higher, in contrast to known devices, a methane detection sensor is additionally connected, connected to the recording and control unit by its output, and a coordinate determination circuit connected its input-output with input-output of the registration and control unit, the unit of broadband converters, in which the broadband converters are made in the form of a sealed cylindrical vessel, times equipped with a partition into two compartments filled with an electrically conductive liquid, the partition is equipped with an opening in the middle and sides of which mesh electrodes are located, the ends of the cylinder are made in the form of elastic membranes, the broadband transducer block is connected to the input and output of the recording and control unit by an input-output block highly sensitive seismic sensors contains four transceivers of acoustic signals mounted on a perforated bracket, with the formation of two single-channel and one vuhkanalnogo transceivers, antennas with the placement of single channel transceivers for a distance of 1000 mm from each other in the end zones of the perforated bracket; the two-channel transceiver is formed of two transceivers that are 50 mm apart, one of which is located 200 mm from the first single-channel transceiver, and the second single-channel transceiver is located at a distance of 800 mm from the second single-channel transceiver, the transceivers are located on a perforated bracket with the formation two measuring bases having a common center, the body of the mobile multi-channel seismometric complex is made of high-strength aluminum a mini-alloy with a protective coating in the form of anodic oxidation with a multilayer paintwork.

The essence of the proposed technical solution is illustrated by drawings.

Figure 1. Characteristics of the passive continental margins of the continental shelf in accordance with Article 76, paragraph 4 (a) (i) of the “Convention on the Continental Shelves” and the placement of seismic signal recording means. In figure 1, the positions indicated are: coastline 1, continental shelf 2, foot of the continental shelf 3, Gardiner line 4, fault 5, reference coast station 6, mobile stations 7, recording devices 8, artificial Earth satellites 9.

Figure 2. The block diagram of the recording device 8 includes a block of highly sensitive seismic sensors 10, a remote distributor 11 with cable lines, a recording module 12 with a block of filters and amplifiers, a board of analog-to-digital converters 13, a board of digital-to-analog converters 14, a computer 15, a GPS receiver 16, power supply unit 17, calibration unit 18, processing unit, analysis of signals and their spectral characteristics 19, software 20 type Mathlab version 6.0 and higher, methane detection sensor 21 connected to its output with the regis unit unit, the coordinate determination circuit 22, connected by its input-output to the input-output of the recording module, the block of broadband converters 23.

Figure 3. The block of broadband transducers 23 includes three sensors oriented along three planes. Each sensor is made in the form of a sealed cylindrical vessel 24, divided by a partition 25 into two compartments 26 and 27 filled with electrically conductive liquid, the partition 25 is provided with an opening 28. Mesh electrodes 29 are located in the middle and sides of the cylindrical vessel 24, the ends of the cylinder 30 are made in the form of elastic membranes. The block of highly sensitive seismic sensors 10 contains four transceivers of acoustic signals mounted on a perforated bracket, with the formation of two single-channel and one two-channel transceivers, with the placement of antennas of single-channel transceivers at a distance of 1000 mm from each other in the end zones of the perforated bracket. A two-channel transceiver is formed of two transceivers that are 50 mm apart, one of which is located 200 mm from the first single-channel transceiver, and the second single-channel transceiver is located at a distance of 800 mm from the second single-channel transceiver, the transceivers are located on a perforated bracket with the formation two measuring bases having a common center. The body of the mobile multi-channel seismometric complex is made of high-strength aluminum alloy with a protective coating in the form of anodic oxidation with a multi-layer paint coating.

Mobile stations 7 can be made in the form of floating vehicles, for example, in the form of ship vehicles or drifting autonomous stations. In this case, the mobile stations 7 are equipped with navigation means for measuring the speed, course, coordinates, sonar (multi-beam and sounding sonar, side-scan sonar, panoramic profiler, sonar communication channel), gravimeter and magnetometer.

The block of broadband converters 23 consists of primary sensors and a processing unit. Each primary sensor is a sealed cylindrical vessel, divided by a thick partition into two compartments filled with a special electrically conductive liquid (aqueous solution of potassium iodide and iodine). To allow fluid to flow from one compartment to another, a thin hole is made in the center of the partition, and the ends of the cylinder are made in the form of elastic membranes (in a different design, instead of membranes, each compartment has cavities filled with inert gas). Mesh platinum electrodes are located in the middle and sides of the hole, to which a weak constant voltage is applied: plus to the central anode and minus to the cathodes. As a result, an equilibrium redox reaction occurs. With increasing direct voltage, the current through the cell grows rapidly at first, then when the equilibrium state of the ions is reached at a voltage U _us , a saturation current I _us occurs, which changes quite slowly. Upon reaching the breakdown voltage U _direct current through the cell increases dramatically. With a reverse polarity voltage, a small reverse current flows. The work area lies in the range from U _us to U _ave . The operating point is usually set in the middle part of this region at U _p ≈0.5 V. To compensate for the initial current I, _we used two electrolytic cells in one housing, which form a differential circuit that allows providing zero output voltage. When mechanical vibrations are applied along the axis of the cylinder, the inertial fluid flows through the hole to the beat of the vibrations. Due to the mechanical transport of ions, the equilibrium state is violated, and a current proportional to the mechanical action appears between the electrodes. Primary sensors are installed in horizontal and vertical planes. The main advantages of the sensors are low sensitivity to shocks (up to 30g), the ability to register signals in the vertical, horizontal and azimuthal directions, as well as small dimensions and weight, economical power supply. The processing unit collects, digitizes and accumulates signals from sensors. The subsystem is a hardware-software complex for an Intel-compatible processor family and is equipped with debugging and testing tools. At the same time, there are three modes for registering signals: continuous, start-stop according to a given program, and start-stop with control by signal level. The parameters of the processing unit are controlled according to the results of express signal processing based on the analysis of the energy level and spectral composition using fast real-time algorithms.

The hardware of the subsystem for collecting and recording data consists of the following main elements: a remote digital recorder, an accurate time storage unit, a cable communication channel, a central station microcomputer with a hard disk drive. Let us briefly consider these elements.

The remote digital recorder is a micromodule controller based on an Intel-compatible NEC V25 processor with a PCMCIA flash drive and a standard output communication tool based on the RS232 interface. The microcontroller contains a built-in multi-channel ADC with a serial interface, programmable timers, real-time clocks, digital I / O ports, external hardware interrupt channels and a direct memory access channel. Distinctive features of the controller used are miniature dimensions (100 × 70 × 30 mm), low consumption (0.5 W), high reliability and low cost.

The accurate time storage unit is designed using energy-saving technologies, entirely on CMOS elements. It is used as a generator of reference minute (second) marks for synchronizing the clock of the microcontroller of the central microprocessor.

The central microprocessor of the station is assembled on the basis of PC-compatible equipment for industrial automation using a processor board such as MicroPC from Octagon Sistems (USA). The applied design meets the stringent requirements of industrial operation, in particular, it is able to withstand large overloads during impacts and has an increased MTBF. Having saved the computing power of a modern personal computer, it has small dimensions, weight and power consumption (several units of watts). Moreover, which is especially important for a sealed bottom station, additional cooling (fan) is not required. The presence of a 16-bit IDE interface for a hard disk drive 5 allows the use of modern high-capacity drives and, accordingly, increase the battery life of the station using the continuous registration mode. The registration system as a whole is fully compatible with PC and runs on ROM-DOS (DOS 6.22).

To expand the dynamic range of the recorded signals, two gain channels, sensitive and coarse, are allocated for each registered component, with a ratio of gain K ₁ / K ₂ = 2 ⁿ , where n is selected from the level of the real seismic background at the station installation site. Thus, it is possible to bring the dynamic range of the station under low noise conditions to 130 dB using an inexpensive and reliable 12-bit ADC.

The exact time service is implemented on the basis of periodic synchronization of the internal clock of the PCR microcontroller with reference minute marks from the exact time storage unit 8. Since the data of the real-time clock registers of the microcontroller can be updated with a certain delay, second marks of the exact time storage unit are used to achieve the required accuracy of the time service 18 or a mixture of second and minute marks, which are entered through one of the digital inputs of the microcontroller in time with the conversion frequency ana log signal and are recorded in the least significant bit of the word ADC. Thus, the digitized data contains a pilot bit, the front of which is tied to the front of the reference mark with an accuracy not worse than one reference.

Most of the time, the central microprocessor of 4 stations is in the "Sleep" mode and is turned on only for the time of transferring data from the flash card to the hard disk and to perform control functions for servicing the station. Using the "Sleep" mode can dramatically reduce the energy consumption of the station as a whole.

The software of the submarine station is entirely written in the high-level C language, which, at the same time, allows for fine control of the hardware up to bitwise operations in their registers specific to assembler. The use of Borland's C language compilers allows the generation of codes that are largely invariant to the type and class of the IBM-compatible computer used by appropriately adjusting the compiler environment. As a result, the program turns out to be workable for all types of processors, starting with the 8086/8088 family and ending with 80486 and Pentium.

The version of the program is located in the EPROM microcontroller. The launch of the program for execution and, accordingly, the start of work occurs automatically when power is supplied to the microcontroller.

The seismic signals are digitized using the external interrupt mechanism by the signals of the programmable internal timer of the microcontroller. Digitization and data collection are carried out with pre-processing elements to improve the metrological characteristics of the registration channels. Analog signals are digitized at a higher frequency, then digitally filtered and averaged by triples and fives, followed by discharge to obtain the desired sampling frequency. All filtering procedures in the system are performed in real time using Butterworth's fast recursive filters. Two types of filters are used. It is advisable to use recursive filters with integer coefficients at the characteristic points of a program with a high data canalization rate (for example, with input filtering). Such filters do not require floating point calculations and are much faster than their counterparts with "exact" coefficients. However, it should be noted that the procedure of rounding the coefficients causes a number of known problems and, in particular, can lead to instability of the filter. In other characteristic nodes of the program, where samples with a sampling frequency of 100 Hz and below are subject to digital filtering, it is possible to use recursive filters with "exact" coefficients, presented in the form of floating point numbers. Such filters are more stable, functionally closer to their analog prototype, but they lose in speed. Recursive filters of this type are used, in particular, in the algorithm of the detector of seismic signals. Typically, in analog and digital devices, Butterworth high-order filters obtained by cascading second-order links give the best result.

In order to increase the station’s autonomy time, in addition to the continuous operation mode, a standby recording mode with a brief record of the history of the event is provided. To organize the standby mode, the system uses the so-called STA / LTA detector, which is most often used for the purpose of detecting seismic signals, using the algorithm for the ratio of signal energies with short-period and long-period averaging. The disadvantage of such a detector, as you know, is to skip the first entry when working on a strongly coherent signal. To improve the characteristics of the detector, a three-channel version was developed using the group coincidence attribute “2 of 3”. This means that the data of the three seismic channels are analyzed by three independent detectors, and the detection signal is generated only when the alarms coincide in at least two of the three channels. This method increases the reliability of the system in standby mode. If an event is detected in the system, a signal is generated that allows you to save the previous data file in external memory, otherwise it is erased. Thus, the standby mode of registration is carried out with the recording of the background before the event.

The remote digital recorder program contains a telecommunication driver that supports half-duplex communication with the central computer of the bottom station. Communication is based on the original high-performance binary communication protocol using separate RS232 interface signals. Communication and data storage are controlled by the central microprocessor of the station. The management program supports the file organization adopted in DOS. Arrays of data are stored on the hard disk in files whose format meets the accepted station requirements, and if necessary, using the simplest software supervisor, the formats can be integrated into any of the seismological data exchange formats existing in the world practice.

Unlike known devices that use a separate analog recorder with a frequency range from 0.1 to 15 Hz, the device used uses a recorder with a lower frequency range from 0.003 Hz.

The operation of the entire station is controlled using a central microprocessor such as MicroPC, and the main accumulation of signals is carried out on the hard disk. All this made it possible to expand the frequency range of the digital recorder to 15 Hz from above, the dynamic range to 120 dB (with automatic switching of sensitivity to 2 sub-bands) and completely eliminate analog recording.

When registering seismic signals at the bottom, one of the important areas of use of broadband bottom seismographs is the study of microseismic noise excited by sea and ocean waves. Microseisms appear in a wide range of frequencies and serve as a natural background that determines the sensitivity threshold of seismographs. By means of the proposed device, characteristic microseisms are also recorded with a period of about 6 seconds, microseisms with periods of 20 and 100 seconds are also detected, which makes it possible to isolate both volume P and S waves and Love surface waves (oscillations in the frequency range 0.0125-0, 05 Hz) and Rayleigh.

At the same time, the excitation of tsunami waves by earthquakes in a compressible fluid is accompanied by the generation of hydroacoustic fields in a wider frequency range, and their energy can exceed the energy of tsunami waves. In this case, low-frequency fields (F <1 Hz), like tsunami waves, are excited mainly due to vertical movements of the bottom in the epicenter of an earthquake. Excitation of high-frequency hydroacoustic fields (phase T) occurs over a much larger area and substantially depends on the topography of the bottom. Therefore, high-frequency hydroacoustic fields contain relatively less information per se about the forms of bottom movement in the epicenter of an earthquake.

The presence of intense low-frequency acoustic fields in the tsunami focus is observed in the range of 0.05-0.4 Hz, while the main energy of elastic vibrations exceeds the tsunami wave energy by about 300 times (Levin B.V., Nosov M.A. Tsunami physics. - M .: Janus - K, 2005, 360 pp.).

At very low frequencies (below 0.01 Hz), due to the negligibly small thickness of the ocean layer compared to the wavelength, anemobaric waves are directly excited due to atmospheric pressure drops (Rabinovich AB Long gravitational waves in the ocean: capture, resonance, radiation .-SPb .: Gidrometeoizdat, 1993, 325 p.). Part of the energy of microseisms propagating at small angles to the vertical is dissipated in the thickness of the Earth in the form of body waves in accordance with the law 1 / R ² . The other part of microseisms due to refraction or reflection from the underlying layers returns to the upper boundary and undergoes repeated reflections and transformations of longitudinal waves into transverse and vice versa. In this case, surface waves of various types can form, which can propagate over long distances with low attenuation (the energy attenuation coefficient is proportional to 1 / R). In this case, Rayleigh, Stoneley and Love waves are formed. The speed of Rayleigh waves is always greater than the speed of sound in water. Therefore, at sufficiently high frequencies, when the wavelength in the water layer is commensurate with the depth of the ocean, part of the energy of the Rayleigh waves passes into the water. The amplitude of the waves decreases. Estimates show that the effect of the water layer at an ocean depth of 4 km begins to affect frequencies of about 0.01 Hz. At a frequency of about 0.1 Hz, the wave reflected from the surface of the liquid passes to the bottom in antiphase, i.e. the maximum suppression of the Rayleigh wave occurs. In this case, the main mode undergoes the greatest attenuation, since its antinode is located at the water-ground boundary. Higher modes attenuate less because there are a number of antinodes of these modes in the underlying layers. Due to the exchange of acoustic energy between the liquid and the elastic base at a sufficient depth of the ocean, a surface Stoneley wave can arise and propagate along the bottom. At the same time along the vertical on both sides of the boundary are inhomogeneous damped waves. With an ocean depth of 4 km, the formation of Stoneley waves is possible at frequencies starting from about 1 Hz, and at frequencies above 10 Hz the limiting effect of the depth of the ocean can be neglected. The speed of a Stoneley wave is less than the speed of waves in water and soil, so there is no energy loss due to "leaky" waves. This implies the possibility of Stoneley waves propagating along the seabed over long distances at high frequencies, in contrast to Rayleigh waves. Love surface waves are transverse vibrations with horizontal polarization. Therefore, they cannot be directly excited by waves incident on the boundary from an aqueous medium or due to drops in anemobaric pressure. Their appearance in the composition of microseisms is associated with the transformation of Rayleigh waves on inhomogeneities of the earth's crust, as well as with seismic emission from the crust and upper mantle.

The method is implemented as follows.

The means for recording hydroacoustic signals are placed, which are broadband bottom seismographs directly at the water-ground boundary in the coastal zone and at a distance from the coastal zone, as well as at different depth horizons using autonomous bottom stations, underwater observatories, and anchored platforms for installation. The analogue of broadband seismographs are broadband seismographs such as EHP-17, EHP-20.

Broadband seismographs of the G.Streckeisen Messgeratebau type (Switzerland) and Guralp (England) type STS-1 and CMG-3 are installed on coastal mobile stations.

The measuring base on the seabed is formed by placing seismic receivers at a distance of not more than 5 km from each other, with the formation of an isosceles triangle in the underwater space, at the tops of which seismic receivers are located, while the hydroacoustic antennas of seismic receivers include four transceivers of acoustic signals mounted on a perforated bracket, with the formation of two single-channel and one two-channel transceivers, with the placement of antennas of single-channel receivers transmitters at a distance of 1000 mm from each other in the end zones of the perforated bracket; the two-channel transceiver is formed of two transceivers that are 50 mm apart, one of which is located 200 mm from the first single-channel transceiver, and the second single-channel transceiver is located at a distance of 800 mm from the second single-channel transceiver, the transceivers are located on a perforated bracket with the formation two measuring bases having a common center; seismic oscillation receivers are located in the shelf zone, along the foot of the continental slope and along the axis of the perpendicular Gardiner line along the fault boundaries.

Hydroacoustic signals are recorded with phases of the type PP, S, and T. The seismic noise at frequencies of 0.008-20 Hz, the hydrodynamic noise of the sea at frequencies of 0.01-100 Hz, the pressure of the tsunami waves at the bottom at frequencies of 0.01- 0.01 Hz.

The phase T signal received in the coastal wedge is determined in the frequency range 34 ... 75 Hz at a quantization frequency of 160 Hz using the pseudo-differential parabolic equation, which provides sound fields in a two-dimensional inhomogeneous ocean with variable bottom topography and sound velocity profile with a given accuracy for any angle range slip of local normal waves, taking into account the interaction between them. Since the observed signal S (t) is the sum of signals from successively excited layers, representing the signal as a vector of a column of time samples and denoting column vectors of signals from successively excited layers by s _i , we have S (S ₁ , S ₂ , ... S _n ), (a ₁ , a ₂ , ..., a _n ), a _i - the essence of the amplitude of the scatterers. As the decisive statistics, the sum of the squared amplitudes is used, which has the maximum value for the signal of the expected structure. The estimate is obtained by the least squares method, since the system of linear equations is uncertain.

Performing an assessment for each point in time, get its time dependence. The presence of a maximum in it means the presence in the source of the expected structure of the excitation of the sound field. When plotting the critical statistics of the abscissa of the global maximum, it corresponds to the time of arrival of the total scattered signal. The arrival of an acoustic wave of seismic origin is determined by the magnitude of the frequency shift of the scattered radiation, while using the recording means located in the near zone of the earthquake source at external signal receiving and processing stations, the low-frequency components of the scattered signal are analyzed, and noise is used as reference quasi-harmonic high-frequency signals shipping, and by means of registration tools located in the coastal zone, determine the moment of occurrence and direction of arrival acoustic waves by narrow-band filtering and spectral analysis. Phase separation of the PP, S, and T phases is carried out by narrow-band filtering using Butterford recursive filters, while the input filtering is performed by recursive filters with integer coefficients, and signals with a sampling frequency of 100 Hz and below are filtered with coefficients in the form of floating point numbers. Acoustic signals are recorded by means of broadband bottom seismographs with at least three seismic channels, the signals being analyzed by three independent detectors, and the detection signal is generated when the alarms coincide in at least two out of three channels. Spectral analysis is performed as body waves of the phases PP and S, and surface waves of Love, Rayleigh and Stoneley.

When registering seismic signals at the bottom, one of the important areas of using broadband bottom seismographs is the study of microseismic noise excited by sea and ocean waves. Microseisms appear in a wide range of frequencies and serve as a natural background that determines the sensitivity threshold of seismographs. By means of the proposed device, characteristic microseisms are also recorded with a period of about 6 seconds, microseisms with periods of 20 and 100 seconds are also detected, which makes it possible to isolate both volume P and S waves and Love surface waves (oscillations in the frequency range 0.0125-0, 05 Hz), Rayleigh and Stoneley (1-10 Hz). At coast stations, the Rayleigh wave is recorded in the zero mode.

New distinctive features consisting in recording the pressure of tsunami waves at the bottom at frequencies of 0.003-0.01 Hz using bottom seismographs with broadband seismic channels of 0.003-20 Hz, broadcasting recorded signals through a hydroacoustic communication channel to drifting buoys located in the studied points, registered signals from which they transmit via satellite channel to coastal reference points, in additional recording of seismic noise at frequencies of 0.008-20 Hz at the water-ground boundary, with separation from The spectrum of horizontal components of odd harmonics is 0.003 and 0.005 Hz, and from the spectrum of the vertical component of even harmonics of 0.002, 0.004, 0.006 and 0.008 Hz, the measurement of the tide level in the zone of location of coastal reference points, allows you to get an operational assessment of the seismic state of the studied areas with a more reliable forecast of possible seismic phenomena.

Known methods allow to achieve a technical result, which consists in increasing reliability, only in an isotropic field, since the nature of the decrease in the intensity of the sound signal with distance from the source in a horizontally inhomogeneous field (especially in the ocean) differs sharply from the same dependence in an isotropic field. Mesoscale inhomogeneities of the ocean (fronts, rings) dramatically rearrange the sound field, causing fluctuations in signal intensity up to 5 dB when predicting their range (D) up to 10 km. Therefore, for an effective forecast of hydroacoustic conditions in abnormal areas, a clear establishment of centers and boundaries, as well as determination of the parameters of disturbing formations, are necessary. Uncertainty in the calculation of the sound field by climatic data or the reference field is expressed in standard deviations of the real level from the reference at 4-9 dB, at D = 90 km, which corresponds to an error in the forecast of the expected range of hydroacoustic systems by 60-90%. The use of a single curve of the vertical distribution of the speed of sound for acoustic calculations is permissible only at short distances (up to 10 km), which is extremely rare in real conditions. By the magnitude and direction (sign) of the horizontal gradient along the signal propagation path, one can judge the degree of variability of the intensity of the sound field at the receiving horizon relative to a fixed source. For calculations of the acoustic field, the parameter is the sound velocity profile, which exactly matches the actual profile at the source location. However, when using regime information, the mean-square profile, as a rule, does not coincide with the actual one, which leads to additional random errors in the final result.

In the proposed method, by means of sensors of weak seismic signals measuring three components (horizontal, vertical and inclined components) in the range of 0.008-0.1 Hz, which are cycle meters and installed at several horizons in depth by means of anchor devices, and sensors of strong bottom movements in the range 0.01-20 Hz, which also measure three components and are installed directly on the seabed, register signals at the seawater – sea soil interface.

Acoustic seismic sensors for recording acoustic signals, proton or quantum variometers and magnetometers for measuring the electric and magnetic components of the earth’s natural electromagnetic field can be used as measuring tools installed by means of anchor devices, with the separation of the magnetotelluric component against a background of separation of electric and magnetic sensors by the value Δr≤ (0,013 ... 0,025) r, (where r is the distance between the receiver and the source). In this case, the separation of the magnetotelluric component against the background of interference is significantly simplified, since the interference in the electric and magnetic channels is caused by various sources (they are uncorrelated) due to the spacing of the sensors by Δr. Moreover, the magnetic components of the natural magnetic field are smaller than the electric ones depending on the nature of the geoelectric section far from horizontal inhomogeneities.

As a magnetic field sensor designed to measure the absolute value of the magnetic induction of the earth's field in marine waters to depths of 6000 meters, a sensor with a range of measured magnetic induction of 20,000-100,000 nT is used.

In a specific embodiment, the acoustic measuring means installed by means of anchor devices are a set of sonar antennas.

Each receiving hydroacoustic antenna consists of four hydrophones. The antenna section consists of two single-channel and one two-channel module, located on a linear carrier bracket. The distance between the receiving hydrophones of the two-channel module is 50 mm. The maximum spacing of the extreme receivers on the bracket is 1000 mm. The bracket is perforated, which allows the receivers to be located in close proximity to each other for phase calibration and with arbitrary spacing for measuring the direction of arrival of the acoustic signal. Piezoceramic spheres with a diameter of 30 mm were used as receiver antennas, inside which preliminary amplifiers with a gain of 30 dB were placed. The spheres are placed on a steel plate measuring 145 × 145 × 10 mm, equipped with fasteners and an acoustic plug on the back side. The suppression ratio of the audio signal from the back is at least 30 dB.

The antenna complex consists of an 8-channel 2-section receiving hydroacoustic antenna and a hydroacoustic emitting antenna.

Each section of the receiving antenna is a 4-element non-equidistant hydrophone module designed to measure the projection of the acoustic signal arrival vector onto one of the horizontal axes in the ultrashort base mode, in the direction finding mode, or for receiving signals in the long base mode at 4 operating frequencies. Sections of the receiving antenna are located in a horizontal plane perpendicular to each other.

Thus, when all hydrophones receive at the same working frequency, the mode of determining the delay and direction of arrival of the response from a fixed point of the soil is implemented in the ultrashort base mode, and when each of the hydrophones is tuned to its working frequency, the measurement mode of delays from several points of soil in the long base mode.

As seismic sensors installed directly on the ground along the fault, acoustic seismic sensors are used, which are a three-component seismic-acoustic sensor, which is designed to convert the third derivative of soil vibrations into an electrical signal in the frequency range of 20-1000 Hz, the dynamic range of which is in the 1 / 3 octaves and a central frequency of 30 Hz is at least 60 dB, as well as an SM-5 type seismic receiver (cycle meter), including three seismic sensors with a frequency di pazonom seismic signals 0,003-20 Hz, full dynamic range is not less than 120 dB. A sensor with a range of up to 600 atm with a measurement error of 0.03% was used as a bottom pressure sensor.

The recorded signals are processed for each particular point in time to obtain a time dependence within the boundaries characterizing the state levels of the natural geophysical field and hydrophysical fields.

The control unit of the mobile dispatching station (which is a ship) analyzes the level of signals received through the hydroacoustic communication channel from the sensors of weak seismic signals, and in the case of raising the threshold level, includes sensors of strong movements and, in the case of significant vertical or inclined displacement speeds of the bottom movement elements, generates a message packet , which is transmitted through a satellite radio channel to a strong point. Since the control device operates with inertia, to eliminate the loss of the first introductory strong bottom motions, the signals from the outputs of the weak signal sensors are continuously recorded in the buffer memory, which are then used to determine the vessel's motion elements and recorded in a digital multi-channel information storage device. The threshold level is determined by averaging over a long period of time the seismic noise coming from the outputs of the sensors of weak seismic signals.

The signals received by the receiving antenna of the ship’s hydroacoustic communication channel are formed into information packets for transmission to reference points 10 via artificial Earth satellites. Analogs of the data conversion algorithm are the data conversion methods described in the source: Ilyin A.A., Marinich A.N. et al. Digital terminals of satellite communication systems. - SPb., Deau, 2005, pp.77-78, 89. A linear polarization antenna in the form of an asymmetric half-wave pin vibrator, which provides the best energy characteristics in the field of small elevation angles of satellite devices, is installed on the vessel as a satellite communication antenna.

The hydro-acoustic communication channel provides a range of up to 8000 m with a frequency range of signal transmitters commands 7-10 kHz.

When processing the signals, the sum of the squared amplitudes having the maximum value for the signal of the expected structure is used as the decisive statistic. Calculations are performed for each point in time to obtain a time dependence for each field. The presence of a maximum in it means the presence in the source of the expected structure of the excitation of a field. The global maximum corresponds to the arrival time of the cumulative received signal. Upon reaching a global maximum equal to the average value between the amplitudes characterizing the state levels of the natural geophysical and hydrophysical fields, the possibility of the presence of hydrocarbons within the boundaries of the examined formation is judged.

The separation from the spectrum of horizontal components of odd harmonics of 0.003 and 0.005 Hz, and from the spectrum of vertical components of even harmonics of 0.002, 0.004, 0.006 and 0.008 Hz with registration of sea level at coastal stations, it is possible to exclude the influence of microseismic components, mainly due to the influence of tidal fluctuations.

As a magnetic field sensor designed to measure the absolute value of the magnetic induction of the earth's field in marine waters to depths of 6000 meters, a sensor with a range of measured values of magnetic induction of 20,000-100,000 nT is used.

The dynamic noise of the sea is determined in the frequency range from 5 to 10 Hz by means of a measuring module, including a series-connected hydrophone, pre-amplifier, communication line, broadband amplifier, spectrum analyzer. The received signals about the dynamic noise of the sea are discretized and quantized, and then they undergo spectral processing using the modified periodogram algorithm in the following sequence. From a sequence of signals X ₂ (m) of length L samples, calculate for each sequence

X ₂ (m) fast Fourier transform coefficients

- соответствующее окно. Далее вычисляют периодограмму I₂(f_k)=1/V|Х₂(k)|, где f_k(k/L) - частота дискретного преобразования Фурье,

- энергия окна.

- the corresponding window. Next, calculate the periodogram I ₂ (f _k ) = 1 / V | X ₂ (k) |, where f _k (k / L) is the frequency of the discrete Fourier transform,

- window energy.

выполняется как

.Energy Spectrum Assessment

runs as

.

The dynamic noise of the sea coincides with a frequency of about 5 dB.

To solve such problems, it is necessary to discretize a continuous area of the water area using nodes of a regular grid. Then the graph is determined by setting the connection (edges of the graph) on this grid. Possible relationships are determined by special indexing of the nodes of the regular grid using the Farey-Cauchy tree. Moreover, the approximation coefficients for the fluctuation fields are expressed analytically through the integrals over the fragments of the reference field in individual grid cells.

The recorded signals characterizing the variations of the magnetic field at frequencies of 0.01-1.0 Hz, the magnetic induction of the electromagnetic field at frequencies of 1-200 Hz, the electrical component of the electromagnetic field at frequencies of 1-500 Hz, acoustic noise at frequencies of 5-50000 Hz, seismic noises at frequencies of 0.01–20 Hz, hydrodynamic noise of the sea at frequencies of 0.01–100 Hz in zones of tectonic faults, are processed for each specific point in time to obtain a time dependence within the boundaries characterizing the levels of the state of natural ge of the official field and geophysical field during the phase of the sun and moon being on the same celestial line, as a geophysical field subject to the greatest maximum disturbances in all components of geophysical and hydrophysical fields in a given period.

When processing the signals, the sum of the squared amplitudes having the maximum value for the signal of the expected structure is used as the decisive statistic. Calculations are performed for each point in time to obtain a time dependence for each field. The presence of a maximum in it means the presence in the source of the expected structure of the excitation of a field. The global maximum corresponds to the arrival time of the cumulative received signal. When reaching a global maximum equal to the average value between the amplitudes characterizing the state levels of the natural geophysical and hydrophysical fields and the geophysical field and the hydrophysical field during the phase of the sun and moon being on the same celestial line, by excluding acoustic signals of natural and man-made origin, they judge the possibility of hydrocarbon deposits.

The proposed method implements the technology for constructing a cartographic image based on NURBS in the form of an iterative expert automated procedure. The programming language used is the MatLab language. In this system, the quality of map construction is determined by expert comparison of the position of contours calculated according to NURBS with the position of the corresponding isohypses (isobaths) on the original map.

In a specific implementation of the proposed method, raster maps serve as a source of information about the bottom topography.

In the general case, when approximating the profile of the relief with one-dimensional splines, one should specify the values of the first two derivatives at the end points of the section. However, such information is unknown, and it is impossible to obtain it in practice. Therefore, the simplest cubic spline with zero boundary derivatives was used as the base spline for approximating the relief profile along the section. Due to the fact that there are no explicitly defined two-dimensional splines, since it is impossible to construct an infinite system of algebraic equations for matching the first two derivatives in all directions at the adjacent boundaries of two pieces of a spline surface, the construction of a two-dimensional spline function is performed using the tensor product of one-dimensional splines. The matching of the first two differentials for adjacent rectangular map sections is ensured by overlapping task areas of adjacent NURBS.

Thus, the technology for constructing maps in an analytical form based on NURBS allows you to exclude the triangulation stage and thereby eliminate the disadvantages of existing technologies used in well-known technical solutions. The proposed implementation of the technology can be adapted to other types of source information, and more complex types of basic splines can be included in it.

The construction of a map of amplitude variations of a microseismic signal for each frequency of the spectrum of spatial variations, as well as the binding of each received map to its corresponding depth, is performed by approximating the relief profile along the section relative to the coastline, and a cubic spline with zero boundary derivatives is used as the base spline, with the construction of a two-dimensional spline functions are produced by the tensor product of one-dimensional splines. In this case, the legitimacy of identifying hydrocarbon deposits is carried out by identifying the main geographical patterns of the location of geophysical fields within the study region. Since many shelves are a continuation of the lowlands confined to large platform deflections or syneclises, the sequences performing these deflections are tilted towards the shelf and reach maximum power within it. The high power of terrigenous sediments in oil and gas regions is a favorable condition for oil and gas.

Information sources

1. Patent RU No. 2045079.

2. Patent RU No. 2161809.

3. Copyright certificate SU No. 949574.

4. Patent RU No. 2054697.

5. Patent WO No. 98/37439.

6. Patent RU No. 230000125.

7. Patent RU No. 2251716.

8. Patent RU No. 2336541.

9. Patent RU No. 211,19677.

10. Patent RU No. 2271554.

Claims (3)

1. A method of seismic exploration for the search for hydrocarbons, including the registration of the natural seismic background and seismic signal in the studied space, measured by one or more seismic complexes, followed by mathematical processing of the measured values, preliminary determination of the dispersion curve of microseismic waves characteristic of the study area by synchronous recording microseismic signals by at least three seismic stations with vertical seismic sensors followed by assessment by the obtained data of the dependence of the apparent propagation velocities of microseismic waves on the signal frequency, the determination of wavelengths and the frequency range based on the analysis of apparent velocities, in which the microseismic signal consists of Rayleigh waves, the placement of seismic sensors in the study area so that the distance between them is not more than half of the shortest Rayleigh wavelength, determination of the amplitude non-identity of the measuring channels of seismic sensors in the microseismic frequency band signal by simultaneously registering the microseismic signal with all seismic sensors at one point for a time sufficient to establish the stationarity of the power spectrum of the microseismic signal, followed by determining the logarithmic difference of the spectra of all measuring channels of the seismic sensors, accumulating the power spectrum of the microseismic signal at each measurement point for a time sufficient for establishing the stationarity of the spectrum, calculating the spectrum of spatial variations of the microseismic a needle for each measurement point by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal stored at the seismic station installed stationary for an equivalent time in the same time period taking into account the amplitude non-identity of the measuring channels of the seismic sensors, building a map of the amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, the binding of each received map to its corresponding depth; at the same time, information signals are recorded by their measured components for a period of time sufficient to record a statistically reliable noise signal in the infra-low-frequency range, spectral characteristics are calculated using the Fourier transform of the received signals, and they are analyzed for the presence of false signals and signals from the reservoir with natural hydrocarbons, false signals are excluded from consideration, an analysis of the remaining signals is carried out with a judgment on the presence of whether there are no hydrocarbons, registration and recording are carried out on the vertical components of the information signals in the frequency range 0.5-50 Hz, corresponding to the range of the basement depths, the Fourier transform of the components of the information signals is carried out according to their first derivative, the maximum that is taken as a false signal corresponding to the resonance between the day surface and the foundation - a signal from the foundation, the point with the spectrum at which the presence there is a signal from the foundation with a monotonic decrease in the amplitude of the spectrum towards higher frequencies from the maximum of the signal from the foundation, an observation point in the signal spectra of which there are maxima at frequencies greater than the frequency of the maximum of the signal from the foundation, with their offset relative to other measurements by less than half its width maximum, taken as promising for the presence of deposits from natural hydrocarbons, the presence of hydrocarbons is judged by the change in the spectral power of the information signal at the measured frequency otach, characterized in that the pressure of the tsunami waves to the bottom is additionally recorded at frequencies of 0.003-0.01 Hz using bottom seismographs with broadband seismic channels of 0.003-20 Hz, the recorded signals are transmitted via the hydroacoustic communication channel to drifting buoys located in the studied points, registered signals from which are transmitted via satellite communication channel to reference points, while additionally measuring the magnetic field variations at frequencies of 0.01-1.0 Hz, the magnetic induction of the electromagnetic field at totals 1-200 Hz, the electric component of the electromagnetic field at frequencies of 1-500 Hz, acoustic noise at frequencies of 5-50000 Hz, seismic noise at frequencies of 0.01-20 Hz, hydrodynamic noise of the sea at frequencies of 0.01-100 Hz in zones According to the measured parameters, tectonic faults perform factor analysis at the levels of the natural geophysical background and geophysical background during the phase when the sun and moon are on the same sky line by plotting the amplitudes of the gradients of seismic, geodeformation, geochemical, hydrophysical indicators lei at the basis of measurements of not more than 50-100 km in mid-latitudes and 8-10 km high and equatorial latitudes, respectively, with an orientation measurement means eight rhumbs; seismic noise is additionally recorded at frequencies of 0.008–20 Hz at the water – ground interface, while odd harmonics of 0.003 and 0.005 Hz are isolated from the spectrum of horizontal components, and even harmonics of 0.002, 0.004, 0.006 and 0.008 Hz are isolated from the spectrum of the vertical component, and at coastal seismic stations measure the tide level; registration devices are placed at deep observation horizons that are multiples of 25 m, with a maximum observation horizon of 100 m uniformly distributed in azimuth, hydroacoustic signals are recorded with phases such as PP, Z and T, the arrival of an acoustic wave of seismic origin is determined by the magnitude of the frequency shift scattered radiation, while using registration devices located at a distance from the coastal zone, they analyze the low-frequency components of the scattered signal using A set of reference quasiharmonic high-frequency signals of shipping noise, and using recording devices located in the coastal zone, determine the moment of arrival and direction of arrival of seismic waves by narrow-band filtering and spectral analysis of waves, phases like PP, S and T are isolated by narrow-band filtering using recursive filters Butterfort, while the input filtering is carried out by means of recursive filters with integer coefficients, and signals with a sampling frequency of 10 0 Hz and below are filtered with coefficients in the form of floating point numbers; sonar signals are recorded by means of broadband bottom seismographs with at least three seismic channels, while the signals are analyzed by three independent detectors, and the detection signal is generated when the signals coincide in at least two of the three channels; Spectral analysis is performed both of the body waves of the PP and S phases, and of the Love, Rayleigh, and Stoneley surface waves, the construction of a map of the amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, and also the binding of each received map to the corresponding depth by approximating the relief profile by section relative to the coastline, and as the base spline, a cubic spline with zero boundary derivatives is used, while the construction of a two-dimensional spline function is performed by Then the tensor product of one-dimensional splines. 2. A method for determining the depth of hydrocarbon-productive formations, including the placement of at least four receivers of seismic vibrations capable of detecting vibrations in the infrasonic frequency range and recording an information signal, using the microseismic noise of the Earth as an information signal above a previously identified focus of microseismic activity of oil and gas deposits are placed at the vertices of the quadrangle by seismic receivers capable of recording as tical and horizontal infra-low-frequency seismic vibrations, for a period of time sufficient to record a statistically significant noise signal in the infra-low-frequency range, generated by the oil and gas field, generate seismic vibrations by a vibration source in the range from 1 to 10 Hz, calculate the spectral densities of the vertical, horizontal components , as well as the spectral densities of cross-correlation functions of the recorded infra-low-frequency oscillations, then m, solving the inverse wave problem of the propagation of acoustic radiation from a cylindrically symmetric source, determine the depth of the reservoir, characterized in that the measuring base on the seabed is formed by placing seismic receivers at a distance of not more than 5 km from each other with the formation of an isosceles triangle in the underwater the space at the top of which seismic receivers are located, while the hydroacoustic antennas of the seismic receivers include four transceivers a bushy signals mounted on a perforated bracket, with the formation of two single-channel and one two-channel transceivers, with the placement of antennas of single-channel transceivers at a distance of 1000 mm from each other in the end zones of the perforated bracket; the two-channel transceiver is formed of two transceivers that are 50 mm apart, one of which is located 200 mm from the first single-channel transceiver, and the second single-channel transceiver is located at a distance of 800 mm from the second single-channel transceiver, the transceivers are located on a perforated bracket with the formation two measuring bases having a common center; seismic oscillation receivers are located in the shelf zone, along the foot of the continental slope and along an axis perpendicular to the Gardiner line along the fault boundaries. 3. A seismic receiver, including a mobile multi-channel seismometric complex, consisting of a block of highly sensitive seismic sensors, a remote distributor with cable lines, a recording module with a block of filters and amplifiers, a board of analog-to-digital converters, digital-to-analog converters, a computer, a GPS receiver, a power supply , calibration unit, processing unit, analysis of signals and their spectral characteristics, software such as Mathlab version 6.0 and higher, characterized in that A methane detection sensor connected to its output with the registration and control unit, a coordinate determination circuit connected to its input-output and the input-output of the registration and control unit, and a broadband converter unit in which the broadband converters are designed as a sealed cylindrical vessel separated by a partition into two compartments filled with electrically conductive liquid, the partition is equipped with an opening in the middle and sides of which mesh electrodes are located, the ends of the cylindrical The cores are made in the form of elastic membranes, the broadband transducer block is connected with the input and output of the recording and control unit by its input / output, the highly sensitive seismic sensor block contains four transceivers of acoustic signals mounted on a perforated bracket, with the formation of two single-channel and one two-channel transceivers, with placement antennas of single-channel transceivers at a distance of 1000 mm from each other in the end zones of the perforated bracket; the two-channel transceiver is formed of two transceivers that are 50 mm apart, one of which is located 200 mm from the first single-channel transceiver, and the second single-channel transceiver is located at a distance of 800 mm from the second single-channel transceiver, the transceivers are located on a perforated bracket with the formation two measuring bases having a common center, the body of the mobile multi-channel seismometric complex is made of high-strength aluminum a mini-alloy with a protective coating in the form of anodic oxidation with a multilayer paintwork.

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