Marine self-contained bottom station for seismic survey and seismological monitoring

FIELD: physics.

SUBSTANCE: bottom station is in the form of a bottom-mounted, deep-water float-free geophysical equipment carrier connected to an on-board computer module installed on a vessel. The geophysical equipment carrier includes, arranged in a sealed spherical container consisting of two hemispheres, a recording unit, an orientation determining unit, a synchronisation unit, a hydroacoustic transceiver unit, a release control device, a power supply unit, geophones, a geophone filter unit and an information timing device. The recording unit includes a three-component seismic detector module and a measurement information storage device. The orientation determining unit is in the form of tilt and azimuth sensors and is mounted in a gimbal suspension. A hydrophone, a hydroacoustic antenna, a ballast-anchor and a flash beacon are mounted outside the sealed container. The on-board computer module comprises a digital information recording unit with a measurement information storage device, a control unit, a unit for hydroacoustic communication with the geophysical equipment carrier, a time synchronisation device and a display device. The gimbal suspension is based on bearings with a non-linear friction coefficient. The tilt and azimuth sensors further comprise two gradient meters mounted on an indirectly horizontally stabilised platform. The said platform is also fitted with roll angle sensors, trim angle sensors, angle of attack and skew sensors, linear acceleration and angular velocity sensors, and a computer configured for combined processing of all sensors. The indirectly horizontally stabilised platform is provided with three gimbal frames, which are fitted with three servo-powered torque motors, two three-component accelerometers with a mechanism for displacement relative to each other and a device for measuring linear velocity of the three-component accelerometers. The device further includes the second indirectly horizontally stabilised platform, which is fitted with three servo-powered torque motors, four accelerometers with a vertical sensitivity axis and a mechanism for displacement thereof, a device for measuring the linear velocity of the accelerometers relative to the bottom station, and a device for recording the time at which two accelerometers meet on the beam of the first and second pairs. All the devices are operably linked through the control unit to the computer, which calculates the desired values of the components of the deviation of the lead line in the meridian and in the first vertical, the velocity, the direction of movement, the latitude, the angle of drift, the path radius and the distance on the vertical from gravity meters to the geoid surface.

EFFECT: high reliability of the obtained information owing to high noise-immunity of the bottom station.

 



 

Same patents:

FIELD: physics.

SUBSTANCE: in seismic survey in icy water, streamers are towed behind a vessel under the water surface to avoid collision with ice. GPS readings may not be consistently obtained because the ice prevents a tail buoy with a GPS receiver from trailing from the streamer on the surface Instead, a device is towed on the streamer under the water surface. The absolute position of the streamer is tracked by intermittently bringing the towed device towards the surface so that GPS readings can be obtained. The absolute position of the streamer can then be used in conjunction with compass readings and can correlate various seismic sensor signals obtained along the streamer during the survey. The compass readings can be corrected for declination using declinometer readings, which can be compensated for iron effects from the vessel or other device carrying the declinometer.

EFFECT: high accuracy of survey data.

31 cl, 33 dwg

FIELD: physics; geophysics.

SUBSTANCE: invention relates to geophysics and can be used in seismic exploration to detect oil and gas deposits. The invention discloses a method and an apparatus for marine seismic survey using one or more movable marine seismic vibrators. The sweeping function for the vibrator is based on the criterion of allowable degradation and is a nonlinear function which performs frequency sweeping from top downwards. The obtained data can be used directly without cleaning or can be easily cleaned.

EFFECT: high accuracy of survey data.

21 cl, 11 dwg

FIELD: physics, geophysics.

SUBSTANCE: invention relates to geophysics and can be used for sea seismic works. Claimed are seismic streamer and related method of evaluation of the shape of seismic streamer controlled in transverse direction. This seismic streamer is divided into several adjacent sections of seismic streamer by control devices in transverse direction. Heading transducers arranged fore and aft of every section generate the data on heading. Every section is simulated as a rectangular fore and curved fore section. Section shape is evaluated in compliance with this model from the data on heading towards the section.

EFFECT: higher precision of trial data owing to precision of seismic streamer shape evaluation.

19 cl, 2 dwg

FIELD: physics.

SUBSTANCE: disclosed is a small-size bottom seismic module, connected by a hydroacoustic link to a control station and consisting of a sealed housing, a hydrophysical module, a device for detecting geophysical signals, which includes a bottom seismometer, information storage means, a spatial orientation sensor, a radio buoy, a ballast, a ballast release, a release timer, a flash beacon, a radio beacon, an external communication socket and a power supply. The sealed housing has the shape of a hemisphere which is linked to the base of the sealed housing which is in the form of a plate, on the upper diameter of which there are mechanical elements of the ballast release, which are in the form of straps which are linked to the ballast, tightly adjoining the base of the sealed housing on its lower diameter. The means of communicating with the control station are in the form of a single-relay hydroacoustic link. The spatial orientation sensor consists of an electronic 3D compass, three accelerometers and three angular velocity measuring devices, rigidly linked to the bottom seismometer, and the bottom seismometer is in the form of a wideband molecular-electronic sensor.

EFFECT: high reliability of detected seismic signals.

3 dwg

FIELD: physics.

SUBSTANCE: acoustic signal is emitted toward sea bottom. Signal of sound reradiation from water column is received. Gas flares are isolated from receive signal. Gas flare inclination is used to evaluate the stream velocity profile and direction. Density of gas flare sources on sea bottom and methane flow direction in water for every flare are calculated. Obtained data allows the determination of methane concentration in water column in the area of methane discharge.

EFFECT: higher efficiency and accuracy of evaluation.

1 dwg

FIELD: instrumentation.

SUBSTANCE: offered invention relates to measuring equipment and can be used for development and manufacture of oceanological multichannel information and measuring complexes and development of new measuring oceanological channels. The hydrological-optical-chemical complex contains a unit of hydrophysical measuring channels, a central controller, the first and second modems of the electric communication line, a conducting rope with electric and fibre-optical communication lines, a rotating electric transition, an electric winch, an operator workstation, a unit of optical measuring channels, and a unit of normalising controllers is added to it, and each hydrophysical measuring channel through the corresponding normalising controller is connected to the central controller, besides, the first and second multiport optical modems and the rotating optical transition are added, and each optical measuring channel is connected to the corresponding input of the first multiport optical modem connected through the fibre-optic communication line of the conducting rope to the rotating optical transition connected to the second multiport optical modem connected to the operator workstation. The information from the measuring channels of the hydrophysical module is processed by the normalising controllers, and in compact way by the central controller through the multiport modem is transferred to the onboard device of the probe, and also in creation of conditions for development, manufacture, laboratory and natural studies of new optical measuring channels for identification and registration of quantity of a mineral suspended matter and the weighed organic substance in sea water, integration of currently existing measuring oceanologic channels, creation of the combined channel of the electric and fibre-optical communication line between submersible and onboard devices.

EFFECT: integration in a single hydrological-optical-chemical complex of all available measuring channels of oceanological parameters.

1 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to hydroacoustic equipment and to the creation of deployment-retrieval devices (DRD) of flexible extended trailing antennas (FETA) on submarines and on surface ships. The invention proposes a DRD structure in which the deployment of the antenna to the stream in case some part of the antenna is wound on a winch, and its other part is arranged in a tubular storage unit, is provided by the creation of excess pressure in the tubular storage unit by means of a centrifugal pump, a sealing device on the end face of the tubular storage unit, which is close to the winch, is made in the form of a cylindrical module of the same inner diameter as the tubular storage unit, which is rigidly and tightly attached to it, and the suction pipeline of the centrifugal pump is made of two branch pipes, one of which is directed outboard and the other one is tightly attached to the inner volume of the tubular storage unit with an additional conical flange coaxial to the tubular storage unit and installed near its fore end face between the conical flange connected to the pressure pipeline and the sealing device of the fore end face of the tubular storage unit, the conical flange of the pressure pipeline is oriented with its constriction to the aft part of the tubular storage unit, and the conical flange of the suction pipeline is oriented with its constriction to the fore part.

EFFECT: increasing the safety of deployment and retrieval of flexible extended trailing antennas, some part of which is wound on a winch of deployment and retrieval devices, and some part is located in the tubular storage unit, without its damages or stops.

1 dwg

FIELD: measurement equipment.

SUBSTANCE: invention relates to devices for measurement of geophysical parameters in bottom area of seas and oceans. Substance: seismic module comprises a tight body (1), inside of which there is a hard disk drive (5), a unit (7) of a hydroacoustic communication channel, a ballast (2) breaker (8), a timer (9) of the breaker (8) of ballast (2), a flashing beacon (10), a joint (11) of external communication, a source of power supply (12), a hydrophysical module (13), a radio beacon (14), a seismic sensor (15), a unit (20) of spatial orientation. Besides, the unit (20) of spatial orientation comprises an electronic 3D compass, three accelerometers and three meters of angular speeds rigidly coupled with the seismic sensor (15). The seismic detector (15) is made in the form of a wideband molecular-electronic sensor. The tight body (1) is made in the form of a hemisphere with a base in the form of a plate, along the upper diameter of which there are mechanical elements of the ballast (2) breaker (8) installed. Mechanical elements of the ballast (2) breaker (8) are made in the form of slings (3), which are coupled to ballast (2) and tightly adjoin the base of the tight body (1) along its lower diameter. The hydroacoustic communication channel for connection of the seismic module with the dispatching station is made as single-relay.

EFFECT: increased validity of recorded data.

3 dwg

FIELD: transport.

SUBSTANCE: invention relates to ship building, particularly, to surface scientific and research vessels. Scientific and research icebreaking vessel is proposed for carrying out 3D seismic technology exploration irrespectively to ice conditions which vessel has a hull where seismic equipment is located, as well as a shaft for bay cable laying. To move source of acoustic waves untethered unmanned submersible is used which bases on a vessel and is dropped and lifted via separate vertical shaft using running - pulling tool.

EFFECT: improved operational performance of scientific and research vessel for seismic exploration.

3 cl, 1 dwg

FIELD: physics; geophysics.

SUBSTANCE: invention relates to geophysics and can be used in marine seismic prospecting. Disclosed is an underwater seismic recording system for reducing noise in seismic signals caused by reflected ghost waves or movement through the water. The system comprises two motion sensors. One sensor has a first response and sensitivity to noise caused by movement of the platform, as well as to acoustic waves. The second sensor has a different structure, which insulates the sensor from acoustic waves such that the response is primarily associated with noise caused by movement. Output data of the responses of the two sensors are combined to eliminate the effect of the noise caused by movement. Upon further combination with a hydrophone signal, noise caused by reflected ghost waves is reduced.

EFFECT: high accuracy of prospecting data.

14 cl, 19 dwg

FIELD: physics.

SUBSTANCE: in seismic survey in icy water, streamers are towed behind a vessel under the water surface to avoid collision with ice. GPS readings may not be consistently obtained because the ice prevents a tail buoy with a GPS receiver from trailing from the streamer on the surface Instead, a device is towed on the streamer under the water surface. The absolute position of the streamer is tracked by intermittently bringing the towed device towards the surface so that GPS readings can be obtained. The absolute position of the streamer can then be used in conjunction with compass readings and can correlate various seismic sensor signals obtained along the streamer during the survey. The compass readings can be corrected for declination using declinometer readings, which can be compensated for iron effects from the vessel or other device carrying the declinometer.

EFFECT: high accuracy of survey data.

31 cl, 33 dwg

FIELD: measurement equipment.

SUBSTANCE: electromagnetic waves are radiated and the signals reflected from boundaries of interface of layers of the probed medium then the results of measurements are processed. The structural maps of a dome, and also temporary seismic sections of the reflected boundaries of the top part of the sedimentary cover are pre constructed, the materials of geophysical surveys of wells, core materials are studied. The lines of profiles are marked on the surface taking into account the structural maps of the dome and temporary seismic sections of the reflected boundaries of the top part of the sedimentary cover. Lines of profiles are drawn in mutually perpendicular directions through the drilled wells with passing outside the dome contour no less than by 500 m. The coordinates of extreme and critical points of lines of profiles are added into the database. The possible external disturbance are considered, the necessary corrections of coordinates of lines of profiles are added. The lines of profiles are located, the altitude and coordinate points of study are determined. Test studies are conducted in one line of profiles. The duration of record of the reflected wave of measurement of set of the electromagnetic signals registered in a reception point during the pre-set time after the radiation of electromagnetic wave as exceeding a double transit time of an electromagnetic wave to the deepest object of studies is assigned experimentally. On the basis of data on depths and supposed or in advance known values speeds of propagation of electromagnetic waves in the medium received during the analysis of geophysical surveys and core materials the fixed time during which the receiver receives the reflected signals is selected. The sampling step is selected sufficient for the detailed description of the electromagnetic reflected signal in a quantity from 10 to 20 points for the central frequency period. During field observations the radiation of electromagnetic waves from the 10 MW transmitter and reception of the reflected signal is performed consistently by three antennas at three frequencies: 50 MHz, 25 MHz and 10 MHz in the linear and logarithmic modes of record and registration with a step 4-6 m. The impulse received at the highest frequency is considered as reflecting the detailed nature of studies and high resolution, and at the lowest frequency - as the maximum depth of sounding. In the linear mode of impulse registration the reflected signal of the lower part of the section is separated and digitised. In the logarithmic mode the registration of "desensitisation" of high amplitude of a signal and amplification of low amplitude record of the top part of the section is performed. As a result of processing of field materials the temporary sections are constructed on which the wave picture displays the features of the geological structure and composition of rocks. By change of properties of dielectric permeability the boundaries of the interface of layers and the diffracting objects in the fields of electromagnetic waves pre-determined by an axis of phase synchronism of the reflected waves are separated. For visualisation the separation of the return reflection field from the set of the obtained data using the frequency and spatial filtration is used. The summation-subtraction function for radargrams, recorded in the linear and logarithmic modes by means of which the detailed partition of the lower part of a radarogram is achieved. For lithologic- stratigraphical binding of boundaries of the reflected waves the correction of high-speed characteristics of electromagnetic impulse and materials of geophysical surveys of wells and coring data is performed. From this the regularities in nature and distribution of an electromagnetic signal are identified. The objects with weak and transitional reflecting characteristics are separated. The search indicator of the deposit boundary on the temporary section is a reduction of time of passing of the boundary of the separated oil layer and increase of the signal amplitude with respect to indications out of the deposit. The maps of time electromagnetic impulse reflections are constructed, on the basis of which the stratigraphical surfaces of the reflecting horizons of the top part of the sedimentary cover are mapped. By changes of amplitude and sign of electromagnetic signal in various mediums over a deposit, at transition and outside the deposit the maps of oil saturated depths are constructed.

EFFECT: forecasting of deposits of superviscous oils.

11 dwg

FIELD: physics.

SUBSTANCE: method includes regional gravitational and magnetic survey, as well as magnetotelluric sounding of the territory. Zones characterised by local positive anomalies of gravitational and magnetic fields, as well as local fall of electroconductive layer under the trap-rock are identified as inflow channels of magmatic substance in plain view.

EFFECT: accurate mapping of inflow channels of magmatic substance into trap-rocks.

FIELD: physics; geophysics.

SUBSTANCE: invention relates to geophysics and can be used to measure geophysical and hydrophysical parameters in near the bottoms of seas and oceans. The underwater observatory (1) comprises a seismometer consisting of seismic and seismoacoustic modules, a hydrophysical module, a magnetic field sensor, a hydrochemical measurement unit, a methane detector, a pressure sensor, a spatial orientation sensor, a nuclear magnetic resonance sensor, side-looking sonar, connected to a recording and control unit, as well as means of communicating with shipborne equipment, a ballast and a ballast opening switch. The underwater observatory (1) is in the form of a vertically profiling module placed on a moving line (2) between an upper buoy (3) and a lower buoy (4). The moving line (9) is tied through an anchored unit (5) to the ballast (6), and a supporting unit (7), mounted on a sea terminal (8) is connected to a windlass (10), mounted on the sea terminal (8).

EFFECT: broader functional capabilities and high reliability during operation.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: multifrequency-phase sounding method includes an impact by an electric field and a seismic wave on oil and gas deposits (OGD), in result the electric polarisation and movement of oil and gas fluid particles is initiated in a reservoir rock thus forming an electromagnetic field (OGD-response) adequate to the above impact. Parameters of the OGD-response are measured and recorded; the above parameters reflect the changes in phase-frequency characteristics of the seismic wave spectrum when the wave passes through OGD thus enabling the recording of the OGD availability and determination of their characteristics.

EFFECT: improved efficiency and probability of the proved detection of oil and gas deposits.

12 cl, 21 dwg

FIELD: physics.

SUBSTANCE: anchored profiling underwater observatory is linked with a control station and consists of: a subsurface buoy anchored by a steel buoy line which serves as the moving line for the profiling carrier, having a set of measuring sensors, a central microcontroller unit, an electric drive, and which moves on the moving line; a system for digital communication via a contactless inductive tap-in on the moving line, a surface buoy-guidepost with modems for transmission of data and telemetric information via a radio link, a hydroacoustic opening switch of the anchor ballast. On the moving line, over the hydroacoustic opening switch of the anchor ballast, there is a lower spherical buoy, having a modem for a hydroacoustic link inside it, an electric drive linked to a telescopic device, at the end of which a seismometer is mounted. The profiling carrier further includes sensors for determining content of hydrocarbons, carbon dioxide, alpha-, beta- and gamma-radioactivity.

EFFECT: improved operating conditions, broader functional capabilities of the underwater observatory.

2 dwg

FIELD: physics, acoustics.

SUBSTANCE: invention relates to marine geophysics and can be used to prospect for gas hydrates at the bottom of water bodies. An acoustic emission sensor is placed on the shore in a fault area. Daily changes in elastic vibrations of the acoustic emission are recorded. The time of maximum tidal forces in the operating area is determined from the energy of the elastic vibrations. The activation time of the fault area and the "calm" time are determined. Pulses of the magnetic component of the electromagnetic field are detected on the water surface during the activation period of the fault. Anomalies of the electromagnetic field pulses are determined. Samples are collected at the centre of each anomaly or group of identical anomalies. The samples are analysed for the presence and content of the useful component. The boundaries of the deposit are determined from the contours of the anomaly or groups of anomalies in which anomalous content of gas hydrates was detected.

EFFECT: easier prospecting for gas hydrate deposits.

FIELD: physics.

SUBSTANCE: method includes successive operations for acquiring and preparing data by a common-depth-point method, seismic logging, vertical seismic profiling, acoustic logging, gamma-ray density logging and verifying the quality of said data, and obtaining reference values of interval velocities; obtaining an initial hodograph and calculating a synthetic seismogram; performing quality control and inputting a constant time adjustment for landing on the upper reference horizon of the lithologic and stratigraphic system; recalculating the synthetic seismogram and performing quality control again; calculating and inputting an adjustment for landing on the lower reference horizon of the lithologic and stratigraphic system; recalculating the synthetic seismogram and performing quality control; transferring the point of the obtained hodograph to the nearest acoustically weak boundaries; recalculating the synthetic seismogram, followed by quality control and obtaining an apriori hodograph.

EFFECT: high reliability and accuracy of alignment of horizons of a time section and geologic marks of a well.

11 cl, 2 dwg

FIELD: physics, geophysics.

SUBSTANCE: invention relates to field of geophysics and can be used for determination of structural features, lithology and type of fluid saturation of reservoirs. According to the offered method the time-space and/or spatial - frequency data of electromagnetic measurements are obtained with the subsequent reconstruction of volume distribution of conductance of geological model of medium. Then the interval aggregate longitudinal electrical conductance of medium are calculated, the identification in the medium of reservoir beds with abnormal aggregate longitudinal electrical conductance is performed, the positions of axial surfaces of reservoir beds are determined, the thickness of reservoir beds corresponding to positions of axial surfaces is determined, the resistivity is determined using the value of interval aggregate longitudinal conductance of the film inside the bed for each point of measurements. The initial geo-electric model of medium is verified and disagreements are corrected. The variations of interval values of resistivity are determined. In the zone band of sharp decrease of specific resistance the coefficient of porosity of selected layers is determined, using which the capacity of reservoir bed, and also the nature of saturating fluid on the basis of interval resistivity ρp and petrophysical or statistical data are determined.

EFFECT: improvement of accuracy of the prospecting data.

5 cl, 8 dwg, 1 tbl

FIELD: physics.

SUBSTANCE: method includes constructing a "zero" depth model for potential ore-bearing areas based on a database of physical properties of rocks making up the model section, and materials of small-scale gravitational and magnetic exploration. The "zero" depth model is in the form of depth sections on which all detected bodies are assigned corresponding intervals of variation of density and magnetic characteristics. The depth model is interactively selected by solving a series of inverse problems. When selecting the depth mode, the shape of separate model bodies and physical parameters thereof (density and magnetisation) are varied until the calculated gravitational and magnetic fields almost match the observed fields. The obtained non-uniform distribution of rock density and magnetisation is interpreted using reference genetic models of the ore-magnetic systems, with construction of geologic-geophysical profiles. On -geophysical profiles with a sharp change or displacement of isolines of the density and magnetisation fields, large faults and regions of low-density nonmagnetic rocks are selected as residual sources of cotectic granites (sources of fluids, ore substances and energy), and off-shoots therefrom are delineated as the predicted ore deposit zones.

EFFECT: predicting a blind ore body associated with granitoids with high reliability.

8 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes performing three-dimensional seismic prospecting operations, drilling wells with taking of core, electric, radioactive, acoustic and seismic logging, testing of wells. On basis of drilling data and geophysical well research standard modeling seismic and well spectral-time images of oil-productive deposits and their spectral-time attributes are determined. On basis of data of surface three-dimensional seismic prospecting in area of wells standard experimental spectral-time images of oil and gas productive porous collectors and their volumetric spectral seismic attributes are determined on basis of use of spectral-time analysis of seismic prospecting data in goal range of recording and numeric estimation of its results. Following mutual correlation of values of hydraulic conductivity and capacity is performed on basis of drilling geophysical well research data with standard modeling seismic, well time-spectral attributes and volumetric spectral time attributes on basis of seismic prospecting data from area of wells. Optimal volumetric spectral seismic attributes are selected with greatest mutual correlation coefficients. Regression dependencies of optimal spectral seismic attribute are built, or same for complex attribute, with values of hydraulic conductivity and oil and gas productive porous collectors capacity according to drilling and geophysical well research data. Along all tracks of seismic time cube spectral-time analysis is performed and its numeric spectral-time parameterization on basis of optimal volumetric spectral seismic attribute, or complex attribute, with construction of attribute cubes and their following recalculation according to regression dependencies to hydraulic conductivity cubes and capacity cubes.

EFFECT: higher reliability, higher precision.

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