Bottom station for marine geophysical survey

FIELD: physics.

SUBSTANCE: disclosed is a bottom station for marine geophysical survey, having a housing which accommodates a unit of buoys, a signal recorder, movable bars with non-polarisable electrodes, sensors, including induction sensors, an opening switch, an antenna, a power supply unit and an anchor. The bottom station further includes a three-component ferroprobe. At least two devices from a group which includes a sensor, a recorder, a power supply unit and an acoustic system, are placed in separate sealed housings, lying at a distance of 2-5 m from the station and connected to the housing by cantilevers. Induction sensors lying inside the housing of the station are arranged such that the centres of induction coils are maximally close to each other.

EFFECT: high accuracy of exploration data.

4 cl, 2 dwg

 

The invention relates to the field of exploration Geophysics, in particular complexes of equipment for the implementation of Geoelectromagnetic methods apparent resistance and magnetotellurics, and is intended for forecasting of hydrocarbon deposits beneath the seabed and studying the deep structure of the crust.

Currently, marine geophysical researches are widely applied bottom station of various designs and purposes.

Thus, known samosprava electromagnetic station (US 5770945, 2010), which has two mutually orthogonal induction magnetic field sensor located in the housing of the station, and a system for measuring the horizontal components of the electric field, consisting of attached to the shell station horizontal semi-rigid rods ("arms") with a length of five meters each with electrodes on the ends.

The shortcoming is the ability to measure only two components, and that the basic elements of design - logger, power supply, speaker system circuit breaker located inside the station near the primary sensor field - inductive transducers and affect them, increasing the noise level, and also affect the readings of a magnetic compass sensor angle detection, which leads to significant errors in definition wide-angle the orientation station. In addition, this construction requires free space on the deck area of not less than 100 square meters and special equipments to conduct round-trip operations.

Closest to the technical nature of the claimed design is samosprava station for electromagnetic measurements (US 6842006, 2002). The station has a body, a block of glass placesthe, the Registrar of signals, sensors, switch, antenna, power supply and anchor. Rod lengths of five meters and a diameter of about two inches with electrodes forming two mutually perpendicular dipole, can move freely in a vertical plane, which facilitates tripping. Induction sensors (one to four) are located within the length of the rod, usually toward the end to reduce the effect of magnetic masses station on the measurement results of the magnetic field. Conclusion the station overboard with the rod pointing straight down, which, while simplifying the station descent, requires special crane with a large lifting height and, in addition, increases the likelihood of damage to the electrodes and inductive sensors when the flow of water when the shutter does not have time to translate the rod in a vertical position or clinches one or more rods under load.

The shortcoming is also the option of measuring only two components, and not fully eliminated the negative impact associated with interference caused by operating the devices. Another drawback of this and other existing plants is the use of existing stations mainly induction of magnetic field sensors, which have low frequencies high noise level.

The problem to be solved by the authors, is the creation of station construction, allowing to reduce interference and to make more reliable geophysical measurements.

The proposed solution is the use in station three-component flux-gate sensor (PSD), providing for the registration of the three orthogonal component magnetic fields, acute effects of which the other measuring channels are not allowed to use them in ground stations, as well as the creation of a design, allowing to minimize this effect.

The technical result was achieved by the creation of a design in which along with the use of FSD equipment, which may affect the measured signals, is placed in a separate sealed enclosures, separated from the shell station at a distance of 2-5 meters. In the nomenclature of such equipment includes at least two elements from the group, which includes the sensor, datalogger, power supply and akusticheskaya. However, the possibility of withdrawal from the station housing and other advanced elements

Additional improvement work station is achieved by the arrangement of magnetic sensors inside the station so that the centers of induction coils were as close to each other. This arrangement is in contrast to the process, where they are placed on rods provide measurement of the three components of the magnetic field (and not two, as in the similar)that allows you to have complete vector. Through the use of PSD measured three components, but in the low-frequency range (0-1000 Hz).

Made devices are coupled to the body, usually with consoles, made of non-magnetic material, such as plastic or aluminum-magnesium alloy.

Figure 1 shows the station, top view; figure 2 shows the station, side view. It uses the following notation:

1. The station body.

2. Block placesthe.

3. Console units 9, 10, 11, 12.

4. Rod with nepostizhimaya electrodes.

5. Induction sensors.

6. The breakers.

7. Acoustic antenna.

8. The anchor.

9. Flux-gate sensor in a sealed enclosure.

10. The Registrar signals in a sealed enclosure.

11. The power supply unit in a sealed enclosure.

12. Speaker system circuit breaker with a pressure transducer in sealed enclosure is.

13. The sensor angles in a sealed enclosure.

14. Castle temporary mounting consoles in quasi-vertical position.

The station body 1, usually made of resistant material, such as Teflon, to prevent podlipny building of the station to the ground.

Inside the housing 1 are the buoyancy block 2 made of syntactica or steklosfera orthogonal system of rods with electrodes 4, providing measurement of the three components of the electric field orthogonal system 5 inductive sensors, for measuring the three components of the magnetic field in the frequency range 0.001 Hz to 500 Hz, electrochemical breakers 6, the acoustic antenna 7 and the sensor angles 13.

The elements that can influence the measured signals, - flux-gate sensor 9, providing for the registration of three orthogonally component of the magnetic field in the range 0-0,003 Hz, the recorder 10, the power supply unit 11 and the speaker 12, housed in sealed enclosures and separated from the shell station at a distance of 2-5 meters with consoles 3 made of a nonmagnetic material, for example polyethylene, or aluminum-magnesium alloy.

The power supply 11 (battery or battery), usually placed in germanacos on a separate console. This option is preferable for long-term performances, because the ku allows you to completely replace the module when using any type of source and does not require additional costs of ship time. However, its possible that the power supply is placed in the module logger 10 and/or module of the circuit breaker 6 and the flux-gate sensor 9 is fed from one of the sources, for example from the Registrar. This scheme is particularly attractive when dealing with an active source, where the flux-gate sensor is not required and can be limited to two consoles. But in this case it is preferable to use a power supply unit 11 batteries, as they can be recharged without opening the housing through the slot.

Induction sensors 5, fzd 9, the electrodes on the rods 4, as a rule, are connected to the recorder 10; antenna 7, the sensor angles 13, the circuit breaker 6 - module circuit breaker. For ease of connection and reducing the number of connectors on the RS pressurized bodies of the modules can be connected through the optional switching unit that starts and power when working on the first version.

Console 3 can be fixed in a horizontal position or to rotate freely around a horizontal axis to facilitate tripping.

Number 3 consoles depending on the characteristics of the equipment used is generally from 2 to 6. So, when working with artificial fields in the higher frequency range, which do not require flux-gate sensor, apply 2 or 3 console. If this is what the power supply can be placed directly in the RS pressurized bodies of the Registrar 10 and acoustics 12. Angle encoder 13 may be connected to the speaker system 12 for transmission through the acoustic channel on Board the vessel orientation information station at the bottom.

Sealed enclosures modules 9-13 and induction sensors 5, usually equipped with vacuum ports (not shown) to prevent the formation of moisture inside buildings and exceptions taticek.

Depending on the number of consoles and features used trip device body 1 station can be in the horizontal sectional shape of a circle or polygon.

The station operates as follows. Console 3 before descending through the castle temporary mounting 14, generally fixed in a quasi-vertical position with the angle of 10-15 degrees. After lowering station for Board locks 14 are activated automatically under the weight of the station after its separation from the trip device. Console 3 retain the quasi-vertical position during descent due to the flow of water, and when you reach a station of the bottom translated in a horizontal position under the influence of weight modules 9-12 and the initial angle of consoles. On command from the ship station starts to measure, and then after receiving the appropriate signal is triggered breakers 6 and the separation of the armature 8. Console 3 in surfacing are in quasiparticle the ohms position down that provides at least three times faster ascent station as compared with the construction in which the console is fixed horizontally.

The claimed design is successful field trials, showed the possibility to obtain it using more precise data about the structure of the seabed. Compared to other stations of the claimed design is more compact and convenient to use.

1. Bottom station for marine geophysical researches, comprising a housing in which is located a block placesthe, the Registrar signals, motile rod with nepostizhimaya electrodes, sensors, including induction, NC, antenna, power supply and anchor, characterized in that the sensors it further comprises a three-component flux-gate sensor, and at least two devices from the group, which includes the sensor, datalogger, power supply and speaker system, placed in a separate sealed enclosures, separated from the shell station at a distance of 2-5 meters and associated with the case with consoles, and induction sensors, located inside the station, are arranged so that the centers of induction coils were as close to each other.

2. Bottom station for marine geophysical researches according to claim 1, characterized in that it has from 2 to 6 design the lei.

3. Bottom station for marine geophysical researches according to claim 4, characterized in that the console is fixed in a horizontal position.

4. Bottom station for marine geophysical researches according to claim 4, characterized in that console freely rotate around the horizontal axis



 

Same patents:

FIELD: measurement equipment.

SUBSTANCE: device comprises a dielectric body of streamlined shape with installed metering electrodes, a metering unit comprising amplifiers, to inputs of which electrodes are connected, a summator, inputs of which are connected with outputs of amplifiers, and also an additional electrode, at the same time metering electrodes are made in the form of wires with insulated side surface, assembled into a cord or bundle with a polished end, the minimum distance between which and the additional electrode exceeds the size of the turbulence zone, the number of amplifiers is equal to the number of metering electrodes, every of which is connected to the input of the appropriate amplifier, and the additional electrode is connected with the common bus of the metering unit. The additional electrode is made in the form of a hollow metal cylinder installed on the dielectric body, the surface area of which is ten times and more exceeds the total area of the end surface of metering electrodes, at the same time the cord of wires, in the form of which metering electrodes are arranged, is installed inside the second electrode so that its end protrudes beyond the edge of the additional electrode.

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2 cl, 2 dwg

FIELD: physics.

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5 cl, 3 dwg

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58 cl, 11 dwg

FIELD: physics.

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1 tbl, 1 dwg

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EFFECT: higher accuracy and validity.

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1 tbl, 2 dwg

FIELD: physics.

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FIELD: geoelectrical prospecting.

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1 dwg

FIELD: physics; geophysics.

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8 cl, 5 dwg

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FIELD: physics; geophysics.

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1 dwg

FIELD: physics.

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EFFECT: simplified positioning of electrical survey unit and improved measurement accuracy.

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FIELD: mining.

SUBSTANCE: at the profile points the current is supplied through a pair of feeding electrodes to the earth. Current value and potential difference between pair of receiving electrodes is measured. Feeding electrodes are moved with pitch equal to 1 m symmetrically relative to the centre to limit distance between feeding electrodes, which is determined by the specified investigation depth. As per measurement results the apparent specific resistance is calculated. As per data of apparent specific resistance the graph of its behaviour is built depending on half-spacings of feeding electrodes. Specific resistances of frozen beds are calculated as per apparent specific resistance graph. Percentage of clay in unit volume of rock is calculated as per data of specific resistances of frozen beds by the following formula: where ρclay - specific clay resistance, which in permafrost zone section is characterised as constant value which on average is equal to 100 ohm m, ρfb -specific resistance of frozen bed. Lithologic composition of sand-clay complex of frozen rocks is determined as per clay content.

EFFECT: reducing the cost of operations and improving informativity owing to determining lithologic composition of frozen rocks without any drilling data and using common data on geologic structure of investigation region.

1 tbl, 2 dwg

FIELD: physics.

SUBSTANCE: potentially dangerous area is selected on territory to be analysed. At least three measuring modules are arranged on said area. Every said module consists of radiating electrode, main electrode pair with its one electrode making zero electrode, and at least one additional electrode pair. Said electrode pairs of measuring electrode are arranged at 180°/n to each other where n stands for number of electrode pair. All electrodes are located on one equipotentional line of radiating electrode. Electrodes of one pair are arranged on one line with radiating electrode. Directional diagrams of electrode pairs are plotted. Potential difference is measured between zero electrode and main electrode pair, and other electrodes of appropriate measuring module. Abnormal potential difference and direction diagram are used to determine direction for each measuring module to zone of rocks irregularities. Zone location is defined at intersection of said directions.

EFFECT: higher accuracy and validity.

3 dwg

FIELD: physics.

SUBSTANCE: at an observation line, two three-electrode electrical soundings are performed using an apparatus comprising four earthing contacts lying on one line symmetrically about the observation point. The fifth earthing contact relates to virtual "infinity" and is connected to one terminal of an electric current source. Central earthing contacts are connected to a voltage measuring device. When taking measurements, outermost power earthing contacts are successively connected to the other terminal of the electric current source. Potential drop Δ UAMN and ΔUA'MN between receiving earthing contacts is measured. The operations are repeated for all given positions of power earthing contacts. Potential drop for vertical electrical sounding and potential drop for unipolar sounding is calculated from the measured potential drop at each observation point for given differences. The distribution of apparent electrical resistance in sections for two three-electrode and vertical sounding and distribution in section of potential drop for unipolar sounding is determined from the measured and calculated potential drops. The results determine the presence and location in the section of geological irregularities.

EFFECT: high efficiency of detecting geological irregularities in the geological environment.

1 tbl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: complex instrument includes loaded drilling pipe that consists of the first and the second part separated by isolated gap, and distant-measuring cartridge containing distant measuring scheme that includes power source generating voltage drop at isolated gap, and axle current at drilling column that is returned through geologic bed, it also includes isolated measuring electrode connected to the first part and scheme for specific resistance measuring connected in the course of operation to measuring electrode and distant-measuring scheme.

EFFECT: integration of possibilities to measure specific resistance into electro-magnetic distant-measuring instrument and obtaining the data of specific resistance as well as distant measuring.

58 cl, 11 dwg

FIELD: physics.

SUBSTANCE: disclosed is a system for monitoring local surface earthquake precursors on a secure territory, having two supply earth terminals connected to a probe current pulse generator, and a system of receiving earth terminals connected to a receiver which is connected to a signal processing unit. The system of receiving earth terminals is formed by N buried electrodes, N-1 of which are arranged uniformly on a circle of diameter D=0.5-0.6 km, and one central electrode placed at the centre of said circle. Radial conductors are connected each of the N-1 electrodes of the system of receiving earth terminals. Electrodes of the supply earth terminals are spaced apart by a distance L=(15-20)D. The system of receiving earth terminals is directed in the plan randomly relative electrodes of the supply earth terminals and lies from the latter at a distance X=(1.5-1.6)L. The probe current pulse generator generates current pulse bursts with frequency of 0.02-0.2 Hz, burst duration of 10-30 s and current in the pulse of 1-10 KA at least twice a day at the same time of the day.

EFFECT: high reliability of information on the hypocentre of an imminent surface earthquake and its parameters, particularly the event time and amplitude estimate.

5 cl, 3 dwg

FIELD: measurement equipment.

SUBSTANCE: device comprises a dielectric body of streamlined shape with installed metering electrodes, a metering unit comprising amplifiers, to inputs of which electrodes are connected, a summator, inputs of which are connected with outputs of amplifiers, and also an additional electrode, at the same time metering electrodes are made in the form of wires with insulated side surface, assembled into a cord or bundle with a polished end, the minimum distance between which and the additional electrode exceeds the size of the turbulence zone, the number of amplifiers is equal to the number of metering electrodes, every of which is connected to the input of the appropriate amplifier, and the additional electrode is connected with the common bus of the metering unit. The additional electrode is made in the form of a hollow metal cylinder installed on the dielectric body, the surface area of which is ten times and more exceeds the total area of the end surface of metering electrodes, at the same time the cord of wires, in the form of which metering electrodes are arranged, is installed inside the second electrode so that its end protrudes beyond the edge of the additional electrode.

EFFECT: increased resolving capacity and increased accuracy of measurement of small-scale fluctuations of flow speed.

2 cl, 2 dwg

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