Near-bottom electromagnetic measuring device and method for carrying out near-bottom electromagnetic measurements

FIELD: measuring techniques; underwater exploration.

SUBSTANCE: measurement of magnetic field components is done from a point located at a certain distance from the central structure of the electromagnetic measuring system. The point is chosen in such a way that the magnetic field, arising from electrical current in the central structure substantially does not have effect on measurements of the magnetometer. The device, which allows for the given method, consists of central structure, several beams which have a first and second end. The second end is hinged to the central structure, while the first end is free. At least one of the electrodes and magnetometer is joined to each beam.

EFFECT: easement of operation and stability of carrying out measurements.

14 cl, 6 dwg

 

Background of invention

The technical field to which the invention relates.

The invention relates, generally, to systems of underwater research. More specifically, the invention relates to marine electromagnetic measuring system and installation method and return it. One application of an electromagnetic measurement systems is the marine magnetotelluric the receiver.

The level of technology

Magnetotelluric (MT) measurements are used to calculate the electromagnetic impedance of the selected geological formations. MT measurements are particularly useful in areas where no suitable seismic building. For example, MT research is useful in the evaluation of geological formations, such as salts and carbonates. Salts, carbonates and other specific formation can dissipate seismic energy when seismic energy propagates through them, because of the large differences in velocities and irregularities in these formations, while electromagnetic energy fields MT source is distributed through these layers with less distortion. MT method measures changes in the magnetic and electric fields of the Earth and does not use seismic energy to determine the characteristics of the formations.

The MT method is typically used to measure electromagnetic impedance as is uncle frequency. Lower frequencies provide greater depth of penetration. The measured impedance can be converted to apparent resistivity and/or conductivity of selected formations. Impedance measurement at several points and at different frequencies allows the determination of the resistivity and/or conductivity as a function of both depth and horizontal position. Therefore, the MT method can be used to estimate the resistivity of the formations in large areas of the seabed. The resistivity of formations of different formations on the selected area can then be analyzed to determine the geometry of the formations, the presence or absence of hydrocarbons in the selected formations etc.

The MT method is a passive method that uses the natural changes in the Earth's magnetic field as an energy source. MT method includes an underwater system that detects orthogonal magnetic and electric fields near the seafloor to determine the surface impedance. Surface impedance, as described above, can be measured in a wide frequency range and over a large area, where the layered formations are similar to the areas of electric transmission lines. The MT method, which operates in accordance with the principles described above, is described, in which bdih terms in U.S. patent No. 5770945 issued by the Constable. This type of electromagnetic receiver can also be used for reception of electromagnetic signals derived from different types of transmission systems, such as bipole towed cable or the source of the magnetic field of the loop type.

In addition, the receivers can be used to detect electromagnetic radiation originating from other types of signals, such as coming from warships (currents corrosion, electrical circuits, generators, moving mechanisms) or by electric or magnetic sources located in boreholes or nearby terrestrial sources. The goal of these measurements can range from detailed studies of the structure of the conductivity of the section for control of naval movements or operations to determine the signal leakage from the submarine cables.

Underwater system typically includes a device, such as magnetotelluric (MT) measuring system 100, described in the patent issued to the Constable, and shown in figure 1. MT measuring system 100 includes a housing 102 having a battery pack (not shown), the system 104 data collection, two orthogonally oriented magnetic sensor 122 and 124 and four rod 139, 140, 142 and 144, each of which includes an electrode 118, 119, 120, 121, mounted on it to the ice. The electrodes 118, 119, 120, 121 are silver chloride electrodes, and magnetic sensors 122, 124 are magnetic induction sensors.

Rod 139, 140, 142, 144 have a length of five meters and a diameter of approximately 2 inches. Rod 139, 140, 142, 144 are typically made of semi-rigid plastic (e.g. polyvinyl chloride or polypropylene) and fixed to the body. Five-meter length of the rods 139, 140, 142, 144 makes it difficult storage, installation and return of the MT system 100 from a surface vessel (not shown), because the rod 139, 140, 142, 144 are fixed relative to the housing 102 (as shown in figure 1). Rod 139, 140, 142, 144 are intended for location on the seabed, when the MT system 100 is in place.

The housing 102 is attached to the removable concrete anchor 128, which contributes to the immersion of the MT system 100 on the seabed after installation. The housing 102 is normally rests on the upper part of the armature 128, when it is located on the seabed. After completion of the MT measurements anchor 128 may be disconnected, so that the housing 102 may rise to the surface, and it can be taken back to the surface vessel (not shown).

The system shown in figure 1, therefore, consists of two orthogonal electric dipoles and two orthogonal magnetic sensors. Magnetic sensors are located near the power supply and data acquisition system. So carmagnani sensors are very sensitive in the detection of small changes in the magnetic field of the Earth, the magnetic sensors can also detect an equivalent magnetic field generated by current flowing from the power source to the data acquisition system and other electrical equipment. These equivalent magnetic field may damage the data and should be removed from the data using the methods of digital signal processing.

Furthermore, the magnetic sensors are very sensitive to noise. Can be detected any movement of the body and/or rods MT system, caused by sea currents or marine fauna and flora, moving past the MT system, and the movement of the conductive fluid around the respective sensor. These fluctuations of the magnetic field are also registered with magnetic sensors and must be removed using signal processing methods.

There is therefore a need in the MT system, which is less sensitive to movement created underwater events, and to an equivalent magnetic field generated by passing an electric current from the power source on, for example, the data acquisition system. In addition, it would be advantageous to develop an underwater MT system, which is easy to store, install and return back.

Summary of the invention

In one aspect the invention provides the bottom of the electromagnetic measuring device to run under adnych measurements in geological formations with a Central design; plenty of bars, pivotally connected to the Central structure, and the electrode connected with each rod, and/or at least two of the magnetometer connected to the rods.

In another aspect of the invention includes the bottom electromagnetic measuring device to perform underwater measurements of geological formations, with a Central design; plenty of bars, hinged(s) with a Central design; and the electrode and/or the magnetometer connected with each post.

In another aspect of the invention includes the bottom electromagnetic measuring device to perform underwater measurements of geological formations, with a Central structure; at least one arm is pivotally connected with the Central design; and the electrode and/or the magnetometer connected to at least one rod.

In another aspect the invention provides a method of electromagnetic research. The method includes measuring an electric field at a selected distance from the Central design of the electromagnetic measuring system. Then measured the magnetic field in the vicinity of this point.

Other aspects and advantages of the invention evident from the following description and the accompanying claims.

Brief description of drawings

Figure 1 is a prex is given MT system of the prior art.

On figa presents a perspective view of embodiment of carrying out the invention.

On figs presents a perspective view of embodiment of carrying out the invention.

On fig.2b presents a top view of a variant implementation of the invention.

Figure 3 presents a perspective image of a hinge in accordance with a variant implementation of the invention.

4 shows a perspective image of a hinge in accordance with a variant implementation of the invention.

Figure 5 presents a perspective view of embodiment of carrying out the invention.

On figa presents a perspective view of embodiment of carrying out the invention.

On fig.6b presents a perspective image of a rod in accordance with a variant implementation of the invention.

On figs presents a top view cross-section of the rod in accordance with a variant implementation of the invention.

Figure 7 presents a perspective image of the electromagnetic system in accordance with a variant implementation of the invention, after the system was installed in the sea.

On Fig advanced image options for performing electromagnetic system, when it is lowered to the seabed.

Figure 9 presents a perspective view of embodiment of the execution of the electromagnetic system, when it podnimayts is on the surface.

Detailed description

On figa and 2b presents underwater electromagnetic (EM) measurement system in accordance with the invention. On figa presents underwater electromagnetic (EM) measurement system 1, which contains the Central structure 2 having the electrode 3, and the Central structure is connected to at least one rod 4, pivotally connected with the Central design 2. The electrode 3 may be located anywhere inside the Central structure 2. For example, the electrode 3 can be attached to the Central structure 2 and is located in the inner end of the rod 4, as shown in fig.6b. On fig.2b presents underwater electromagnetic (EM) measurement system 1 in accordance with a variant implementation of the invention, which contains the Central structure 2. Many rod 4 pivotally connected to the Central structure 2. The electrode 5 is connected with each rod 4 near its end, and at least two magnetometer 6 is connected to the rods 4. Connection 7 allows you to position the rod 4 and the magnetometer 6 essentially any angle (β) relative to each other. In accordance with the invention, the rod 14 can include at least one electrode and/or at least one magnetometer.

On figs presents underwater electromagnetic (EM) measurement system 10 that include the AET at least one aspect of the present invention. EM system 10 includes a Central structure 12, which contains an electronic circuit such as a power source (not shown separately), the data acquisition system (not shown separately), the microprocessor (not shown separately) and related hardware and software (not shown separately). The Central structure 12 basically includes communication equipment (not shown separately), so that the EM system can be switched on and off remotely. In addition, the EM system 10 also may include, for example, navigation equipment, such as a global positioning system (GMS) or other equipment (not shown separately), which allows to determine the location of the EM system 10 both before and after installation in the sea. The power source may include a battery or any suitable source of power known in the art. Therefore, aspects of the invention, such as the above-mentioned electronic components of the Central structure 12, as expected, are not restrictive. Furthermore, it is believed that the Central design is simply connecting the device to a variety of rods 14. Specifically, in accordance with the option perform data acquisition and signal processing are performed at a remote point, such as a ship, drilling wysk is or ground station. In this embodiment, the Central design is used for connecting rods and receiving signals from sensors for transmission to a remote point. The transfer may be performed on the cable attached to the Central structure, or by wireless transmission.

Plenty of bars 14 (usually four, as shown in figs) pivotally connected to the Central structure 12 using, for example, the hinges 15. The hinges 15 allow the rod 14 to rotate in either direction so that the rod 14 can be located at any angle relative to each other. As described below, the hinges 15 allow the rod 14 to rotate, so that the EM system 10 can be easily stored on Board the surface vessel, installed in the sea and come back with the seabed. In some embodiments, execution of the rod 14 contain rods made of fiberglass. In some embodiments, execution of the fiberglass rods that form the rods 14 have a circular cross-section, the diameter of which is within the range of from about 0.25 to 0.75 inches. For example, one embodiment of contains rods of glass having a diameter of 1/2 inch, while in another embodiment, the diameter is 5/8 inch.

Next, other embodiments of the may contain rods having non-circular cross-section. Nab is emer, one embodiment of contains a rod having essentially elliptical cross-section, as shown in figs, which is designed to minimize the flow resistance induced by the flow of sea water on the bar. In General, regardless of the form of rods 14, the latter preferably designed to have a minimum cross-sectional area, or they are selectively attached to this form that minimizes hydrodynamic resistance, resulting from the flow of sea water on the rods 14, during installation, placement on the site and return EM system 10.

The rod 14 can also be made of other materials (except glass). In General, any suitable material known in the art, may be used to perform the rods. For example, the rod 14 can be made of polymers, composites and other non-conductive materials. In addition, flexible materials, such as chain or conductive materials can be used to remove the location of the sensors, to further improve some of these advantages, such as ease of storage. Therefore, the type of material used to perform the rods 14, as expected, is not restrictive.

On fig.6b presented on the in an embodiment of the invention. The rods 14 can be non-conductive tube, and the free end 8 is open for access of sea water. Sea water comes into contact with, for example, the internal electrode 16A which is electrically connected with the Central design. Free open end can be closed and opened by means of valves which allow the intake or release of water, as well as to isolate the internal cavity of the non-conductive pipe from the external seawater. The valves (19) can operate pressure or electricity. These types of pipes, valves, or without them, easy to install, in some cases, they are cheaper to manufacture and maintain.

In addition, the electrodes 16A, 16B, 16C and 16D can be located in any position along the length of the rods 14. For example, the electrodes 16A, 16B, 16C and 16D can be located at the free end 8 of the rod 14, as shown in figs. In accordance with a variant implementation of the invention, the electrodes 16A, 16B, 16C and 16D can be anywhere between the free end of the rod 14 and a Central construct 2. Another option is run in accordance with the invention has electrodes 16A, 16B, 16C and 16D, inserted opposite the free end of the rod 14 and fixed to the Central structure 2, as shown in fig.6b. The electrodes 16A, 16B, 16C and 16D can be connected with the pipe by sliding on the ele is tradam, reducing the number of underwater connections and cables.

The hinge 15 can have a simple pin connection, as shown in figure 3. However, the hinge 15 can also be performed according to any suitable design known in the art. One embodiment of the hinge 30, which can be used with the invention shown in figure 4. The hinge 30 includes a broad attachment 32, which allows free vertical rotational movement, but distributes the torsion hinge 30 (which may be caused, for example, sea currents or flow of seawater past the bar, when the EM system sinks to the seabed or rises to the surface of the sea) for a more extensive area. The distribution of torsion on a larger area reduces the likelihood that the hinge 30 will be cut and damaged. Moreover, stable hinge 30 helps to prevent further unwanted movement, which could lead to anomalies in the measured data of the magnetic fields, when the EM system (10 in figure 2) is located on the site and operated on the seabed (11 in figure 2).

Referring again to figs, the anchor 20 is connected with the possibility to detach near the bottom of the Central structure 12. The anchor 20 has a ballast, which contributes to the immersion EM system 10 on the seabed p is the following, as the EM system 10 is installed in the sea. The anchor 20 may be disconnected from the EM system 10 in a selected time, for example, send a command from a microprocessor (not shown) on the clamping mechanism (not shown), which connects with the possibility of disconnection, the anchor 20 with the Central structure 12. The clamping mechanism can be any suitable clamping mechanism known in the art, such as described in U.S. patent No. 5 770 945 issued by the Constable.

The electrodes 16A, 16B, 16C and 16D, mainly attached to the end of each rod 14. The electrodes 16A, 16B, 16C and 16D are arranged so that they form two electric dipole with an X-shaped configuration, as shown in figs. For example, the electrodes 16A and 16C may form a first dipole and the electrodes 16B and 16D may form a second dipole. The electrodes 16A-D are used primarily in applications with a controlled source for receiving electrical signals under the action of the remote sources of transmission, such as towing vessels on the cable. Such applications are well known in the industry, including systems for direct current or low frequency (<0.1 Hz), systems with induced polarization (IP) to measure changes in resistance versus frequency and many transfer controlled source. It should be noted that although the electrodes described is in the context of attachment near the rod, placing electrodes around the Central design or it also deals only with fewer adjustments and still reaching at least some of the benefits realized in specific embodiments, a run is described here.

Moreover, in accordance with a variant implementation of the invention magnetometers 18A, 18B, mostly attached to each of the at least two rods 14, forming an orthogonal system for measuring magnetic fields. Rod 14 is designed to rotate in the hinge 15 so that the electrodes 16A, 16B, 16C, 16D and magnetometers 18A, 18B lowered onto the seabed 11, when the EM system 10 is placed in the selected position.

You must understand that although the system described in connection with the preferred option run with magnetotelluric and controlled source electromagnetic measuring system described object and associated benefits do not require the combined use of magnetometers and a system of electrodes. Specifically, magnetotelluric measurement system having a system magnetometers without a system of electrodes with a controlled source, and the system includes only a system of electrodes, both benefit from the described object.

Rod 14 is designed so that have a selected length, which is large enough to possess the magnetometers 18A, 18V at a sufficient distance from the Central structure 12, so that the magnetic field generated by current flowing in the electrical systems of the Central structure 12, essentially not detected by magnetometers 18A, 18B. The magnetic fields generated near the Central structure 12 and measured by the magnetometers 18A, 18B, is inversely proportional to the cube of the distance between the magnetometers 18A, 18B and the Central structure 12. Thus, the location of the magnetometers 18A, 18B near the ends of the rods 14 (for example, at a distance, which is, basically, a few meters from the Central structure 12) effectively eliminates interference and "noise"generated magnetic fields in the Central structure 12. In some cases, it was observed attenuation of the magnetic interference of more than 40 dB when recording systems were taken from the design center at rod.

In accordance with the option run magnetometers 18A and 18B include inductive sensors dB/dt. These inductive sensors based on induction electromotive force due to a time varying magnetic flux. Although it may be used any number of technologies magnetometers, including sensors type of feedback, induction sensors dB/dt provide some advantages, including simplified construction and improved reliability. Ferro is onda river is also suitable in accordance with a variant implementation of the invention. In addition, various designs magnetometers include various configurations to account for the effects of pressure on the sensor. For example, magnetometers can be placed in electrically conductive pressure or internal pressure compensation. Thus, the described subject matter is not limited to any particular type of magnetometer.

The location of the magnetometers 18A, 18B near the ends of the rods 14 (which, in General, relatively light and flexible) also adds additional weight to the ends of the rods 14, which helps to ensure that the magnetometers 18A, 18B are in contact and/or partially immersed in the sea bottom 11 when the EM system 10 is located on the site. The mass increases, the adjacent ends of the rods 14, increases the mechanical stability through a strong hold of the rod 14 in place, so that the flow of sea water or the movement of marine flora and fauna by rods 14 and magnetometers 18A, 18B does not create additional movement of the rod 14 or EM system 10, which could contribute to anomalies in the recorded data of the magnetic fields.

Another embodiment of the invention shown in figure 5, contains four magnetometer 24A, 24, 24C and 24D, each located near an end of each rod 14, forming two orthogonal pairs of magnetometers. The use of two pairs of magnet is meters 24A, 24, 24C, 24D provides additional orthogonal measurement system magnetic fields, which enables the registration of redundant data, thereby increasing the reliability of the recorded data and providing additional number of measurements that can be useful to reduce and/or noise filtering, anomalies, etc.

Embodiment of the mounting of the magnetometer to the rod shown in figa. Magnetometer 26A is connected to the rod 14 with the use of the flexible cable 27A. This option perform additional isolates magnetometer 26A from the movement of the rod 14 and EM system (10 figs), so that the magnetometer 26A, essentially, a fully dynamically isolated from other elements of the EM system (10 figs). However, the cable 27A has a stiffness chosen such that the magnetometer 26A, in essence, supports the desired geometric arrangement. A similar device can be used with other magnetometers (e.g., magnetometer 18A, shown in figs), United with other rods.

In addition, each magnetometer may include dipmeter to measure the inclination of each of the magnetometer relative to the seabed.

Figure 7 presents a view of a variant of execution, shown in figs when the EM system 10 is installed in the sea. Rod 14, in the main, turn down the hinges 15 due to the crystals of gravity, when the EM system 10 is raised to an elevated position above the surface of the sea. Crane (not shown) then lowers the EM system 10 in the sea and detaches the EM system, so that it can fall in a selected position on the seabed (11 pigs).

On Fig presents a view of the EM system 10 when it is lowered to the seabed (11 pigs). Rod 14, basically, turn up the hinges 15 (for example, due to the hydrodynamic resistance offered to the passage of the rod through the sea water), so that the Central structure 12 and the anchor 20 are lowered in front of the rods 14 to the seabed (11 pigs). The ability of the rods 14 turn reduces the "footprint hydrodynamic resistance" EM system 10 so that the rod 14 is rotated up or "folded" position, basically, have a lower hydrodynamic resistance (for example, if they were rigidly attached to the Central structure 12 and could not turn). Reducing hydrodynamic resistance reduces the time spent on lowering the EM system 10 to the seabed (11 pigs). As shown in figure 2, when the Central structure 12 and the anchor 20 is lowered onto the seabed 11, the rod 14 includes electrodes and magnetic sensors, turn down the hinge 15 so that they lie on the sea bottom 11 and form a "V"-shaped dipole pair.

After completion of the electromagnetic (EM) measurements anchor (20 figs) is separated from the main structure (12 figs) in the selected time, as described above. The Central design (12 figs) contains many floating device (22 pigs)connected with it, so uh system (10 figs) becomes floating when disconnected, the armature (20 figs). Floating device (22 pigs) may contain air or any other suitable gas or floating material. Therefore, after removing the anchor (20 figs) uh system (10 figs) begins to rise to the surface of the sea. As shown in Fig.9, the rod 14, in the main, turn down the hinges 15, when the EM system rises to the sea surface. Again, the reduction of hydrodynamic drag created by the ability of the rod 14 to rotate in the hinge 15, reduces the rise time of the EM system 10 and may reduce the number and/or size of the floating device 22 necessary to lift EM system 10 to the surface. If the EM system 10 is on the surface, it can be taken back to the surface vessel (not shown), so that the data can be extracted and so on

Advantageously, as described here, EM system, easy to store, install and return back as rod EM system can be rotated about a Central design. EM systemamerican stable platform for measuring magnetic fields, which is less prone to anomalies caused by sea currents and sea flora and fauna, because the magnetic sensors are essentially dynamically isolated from the main structure. Therefore, described here EM system can produce a more accurate measurement of the resistivity and/or conductivity of the formations and can facilitate the process of underwater electromagnetic research.

Finally, the system and method described herein may be used not only for electromagnetic measurements, but for all kinds of magnets with controlled sources, measurements of marine resistivity DC or marine impedance. They are also applicable for monitoring earthquakes in remote locations that perform underwater monitoring Maritime activity, or for marine monitoring.

Although the invention has been described in relation to a limited number of embodiments, the specialist in this field of technology which benefit from this description, it is clear that can be developed in other ways, which do not go beyond the scope of the invention described here. Therefore, the scope of the invention should be limited only by the attached claims.

1. Bottom electromagnetic measuring device to perform the dive torches etc the different measurements of geological formations, contains

the Central structure;

plenty of bars having a first end and a second end, and a second end pivotally connected to the Central structure, the first end is a free end; and

at least one electrode and magnetometer connected with each post.

2. The measuring device according to claim 1, characterized in that the set of rods contains four bars, situated with the formation of cross-dipole configuration.

3. The measuring device according to claim 1, characterized in that each electrode is located near the first end of each rod.

4. The measuring device according to claim 1, characterized in that at least two of the magnetometer is located near the first ends of adjacent rods.

5. The measuring device according to claim 4, characterized in that at least two of the magnetometer is connected to the rods by means of cables.

6. The measuring device according to claim 4, characterized in that the magnetometers are located at a selected distance from the Central design, so that there is no influence of the magnetic fields generated by electric currents in the Central design on the measurements performed by the magnetometers.

7. The measuring device according to claim 1, characterized in that each arm has a transverse cross-section, designed for minimizat and hydrodynamic resistance, when the measuring device is installed in the sea and returned from the sea.

8. The measuring device according to claim 1, characterized in that the electrodes and magnetometers, essentially dynamically isolated from the main structure.

9. The measuring device according to claim 1, wherein each arm includes a tube having first and second end, and a second end pivotally connected to the Central structure and the first end includes an opening for access of ocean water.

10. The measuring device according to claim 1, characterized in that the magnetometers are missing winding feedback.

11. The measuring device according to claim 1, characterized in that it further comprises an electronic circuit connected to the Central structure, and an electronic circuit is designed to control the measuring system and recording of measurements of electric fields electrodes and measuring magnetic fields, magnetometers.

12. The way to perform the bottom of electromagnetic measurements, which carry out:

measurement of the components of magnetic field at a point at a distance from the Central design of the electromagnetic measuring system selected in such a way that the magnetic field formed by the electric currents in the Central design essentially no effect on the timing that mA is neometro and

measurement of the components of the electric field near the same point.

13. The method according to item 12, characterized in that the electric fields are electric fields of crossed dipoles.

14. The method according to item 13, wherein the components of the magnetic fields are orthogonal.



 

Same patents:

FIELD: technology for finding concealed objects, for example, underground pipelines.

SUBSTANCE: system includes sensor device, having at least two sensors of magnetic field strength vector, positioned in parallel to each other for detecting only distorted magnetic field; device for transformation of direction and value of distorted magnetic field, detected by sensor device, into values for recording and then displaying values in form of letters, digits or graphic symbols; and magnetic marker, formed of magnetic material and attached to cylindrical pipeline. Magnetic marker has upper part and lower part. Lower part has curved structure, such, that center of magnetic material is perpendicular to ground. Polarity of magnetic field is indicated on upper part of magnetic marker.

EFFECT: error-free detection of position, fast attachment of marker to a pipeline, simple measurement of magnetic field.

7 cl, 9 dwg

The invention relates to computing and earthmoving equipment and is designed to collect geological data and location data, as well as to control the digging machine

FIELD: technology for finding concealed objects, for example, underground pipelines.

SUBSTANCE: system includes sensor device, having at least two sensors of magnetic field strength vector, positioned in parallel to each other for detecting only distorted magnetic field; device for transformation of direction and value of distorted magnetic field, detected by sensor device, into values for recording and then displaying values in form of letters, digits or graphic symbols; and magnetic marker, formed of magnetic material and attached to cylindrical pipeline. Magnetic marker has upper part and lower part. Lower part has curved structure, such, that center of magnetic material is perpendicular to ground. Polarity of magnetic field is indicated on upper part of magnetic marker.

EFFECT: error-free detection of position, fast attachment of marker to a pipeline, simple measurement of magnetic field.

7 cl, 9 dwg

FIELD: measuring techniques; underwater exploration.

SUBSTANCE: measurement of magnetic field components is done from a point located at a certain distance from the central structure of the electromagnetic measuring system. The point is chosen in such a way that the magnetic field, arising from electrical current in the central structure substantially does not have effect on measurements of the magnetometer. The device, which allows for the given method, consists of central structure, several beams which have a first and second end. The second end is hinged to the central structure, while the first end is free. At least one of the electrodes and magnetometer is joined to each beam.

EFFECT: easement of operation and stability of carrying out measurements.

14 cl, 6 dwg

FIELD: instrumentation.

SUBSTANCE: group of inventions refers to geophysics, in particular to equipment systems for geoelctric exploration by induced polarisation method and is intended for predicting hydrocarbon accumulations in transit shelf zone at depths up to 10 m. Essence: the system includes a set of sea-bed stations and vessel with generator and exciting field formation unit connected with submerged horizontal towed dipole with energising electrodes; non-radiative ballast device; equipment for reading and writing data from sea-bed stations, recording position and time of current pulses generation and sea-bed stations initialisation. Sea-bed stations are equipped with "braids" positioned along and across exiting line. Each of the "braids" contains at least 3 measuring electrodes located at distance of 50-500 metres from each other. Time series of the first and the second electric potential differences of electric field between electrodes are recorded both during passage of current and during pause between pulses. When interpreting, data on field both during current passage and during pause between pulses is used in wide space-time domain. Resistance of medium and its polarisation characteristics are determined.

EFFECT: providing higher-grade prediction of possible hydrocarbon material sources within studied zone at shallow depths.

3 cl, 6 dwg, 1 tbl

FIELD: physics.

SUBSTANCE: invention relates to marine geoelectrical exploration using controlled artificial sources of electromagnetic field. Using a dipole source, an electromagnetic field is generated inside the analysed medium by sending rectangular electric pulses with intervals in between into the medium. Geometrical probing is done along the profile during the current pulse, and probing on transient processes is done during the interval. Measurements are taken using measuring apparatus mounted on the seafloor, consisting of five electrodes: a central electrode with four others around it on corners of a square, two opposite sides of which are parallel to the axis of the profile. During the current flow period and intervals between current pulses, the second electric potential difference between external electrodes and the central electrode, as well as the first electric potential differences between three pairs of external electrodes is measured. When the dipole source passes through different points, there is provision for equipotentiality of a closed line passing through four external electrodes of the measuring apparatus thereby eliminating the horizontal component of current density in each probing point inside this line. Values of the measured electric potential differences are used to calculate three sets of standard interpreted electrical parametres which are not subject to lateral effect of three-dimensional geological non-uniformities located outside the probing point. Using the derived parametres, the model of the medium is found and time sections of this model is constructed on electroconductivity of elements of the medium, induced polarisation coefficient and decay time constant of induced polarisation potential differences.

EFFECT: elimination of distorting lateral effect on probing results, which allows for deep sea delineation of hydrocarbon accumulation with high contrast.

4 cl, 6 dwg

FIELD: physics.

SUBSTANCE: method is realised using an electromagnetic field source (1113) which transmits current pulses (81, 82) with sharp edges to an immersed vertical transmitting antenna. The electromagnetic field generated by pulses (81, 82) is measured using at least one receiver (1109) fitted with a vertical receiving antenna (1111) immersed in water during a period of time in which there is no transmission of pulses to a transmitting antenna (1108) by the electromagnetic field source (1113). Distance between the electromagnetic field source (1113) and at least one receiver (1109) is less than the depth of the target object.

EFFECT: high accuracy.

12 cl, 14 dwg

FIELD: physics.

SUBSTANCE: geomagnetic field variation is measured simultaneously with two or more magnetometric transducers mounted on mobile carriers placed along the direction of motion. An additional magnetometric transducer is placed 100-200 m from the sea surface on the vertical, said transducer being able to move along as well as across the direction of motion of the first transducer. The speed of the additional magnetometric transducer is at least an order higher than that of the first transducer. A second additional magnetometric transducer lying deep in the sea environment on a carrier is also used to measure geomagnetic field variations. The carrier of this transducer is a self-propelled control device fitted with navigation and hydroacoustic measurement and communication apparatus. The second additional magnetometric transducer can move along as well as across the direction of motion of the first transducer. During survey, inclination of the magnetic field vector is also measured, from which the ratio of gravitational field components Vzz and Vzx are determined.

EFFECT: high accuracy of determining static geomagnetic field.

FIELD: physics.

SUBSTANCE: hand-held detector for detecting and determining the position of concealed objects (44, 84) in an inspected facility (14), having a housing (12), a guiding means (28) mounted on the housing (12) to provide directed movement of the detector along the inspected facility (14) in at least one direction (42) of movement, a measuring device (50) for measuring at least one motion parameter (54) during movement of the housing (12), a control device (26) and an output device (20) for outputting information to the operator, wherein the output device (20) lies on the front side (18) of the housing (12) and is in form of a digital display, and the control device (26), along with the output device (20), is adapted to output at least one dimensional value (88) of distance defined in the direction (42) of movement, in form of an electronically generated digital symbol, and adapted to update the output distance value (88), carried out, at least basically, synchronously with change in the motion parameter (54), wherein the hand-held detector additionally includes an input device (22) and has an input mode with possibility of setting, through the input device (22), a starting point (90) relative which the distance value (88) is determined, wherein setting the starting point (90) is possible without interrupting the process of detecting and determining the position of concealed objects.

EFFECT: easier control of the device, higher rate and easier marking of an inspected facility with simultaneous detection of concealed objects therein and determining location thereof.

7 cl, 6 dwg

FIELD: physics; geophysics.

SUBSTANCE: invention relates to geophysics and can be used for exploration of mineral deposits in a geologic environment. The invention relates to a sensor device and a method for geoelectric survey of a location, stratigraphic arrangement and range of mineral deposits and contiguous rocks delineating said deposits. The disclosed sensor device has a sensor head (51), an end surface which forms a sensor measurement surface (53) and at least one electrode. According to the invention, the sensor head (51) can be brought into contact with the surface of the geologic environment, and a centre electrode (54) and a plurality of external electrodes (55), arranged in a geometrically uniform manner around the centre electrode (54), are placed on the sensor measurement surface (53). The centre electrode (54) and external electrodes (55) are electroconductive and electrically insulated from each other.

EFFECT: high accuracy of survey data of a deposit directly in the development process thereof.

15 cl, 7 dwg

FIELD: physics.

SUBSTANCE: method for detecting the boundaries of local underground peat fire, which includes GPR subsurface sensing of all strata of the peat layer, which consists in the emission of pulses of electromagnetic waves and detecting signals reflected from the boundaries of layers of the probed medium having different electrical properties, ground penetrating radar mounted on the robot platform, which moves along the route scheduled after the patrol conducted surveillance of the controlled area, and GPR profiling is carried out on the given route and in the planned route point to produce sensing of the peat layer in terms of finding the local underground peat fire. The essence of the claimed devices is that the robot for the exploration of the underground peat fires containing tracked chassis, powertrains, controlling and monitoring systems and data from surveillance conducted in real time, and the platform on the last installed ground-penetrating radar for GPR subsurface sensing of all layers of peat deposits in terms of finding a local underground peat fire.

EFFECT: ensuring detection of underground peat fire boundary localization with any depth of peat in areas, where the traditional placement of ground vehicles is extremely dangerous.

2 cl, 2 dwg

FIELD: physics.

SUBSTANCE: presented cognitive mobile complex for geological prospecting in flat deposits of loose minerals in the sedimentary rock contains a self-propelled vehicle with diesel-electric power station, geophysical and drilling modules placed on it. The geophysical module is equipped with sources of location signals and a control unit, the complex is divided into two non-volatile parts: a tractor and a frame. The frame is made with the possibility of fixation on the tractor. The tractor is equipped with a diesel power plant, a battery of batteries, an automatic installation of radioactive tags and a box with a geophysical module containing a computer control unit for geophysical instruments, three rotating locators, and built-in locators of drilling modules.

EFFECT: creation of a mobile device for accelerated automated local geological prospecting in flat deposits of loose minerals in sedimentary rock.

3 dwg

Up!