The method of carrying out engineering-geological survey
The invention relates to the engineering-geological surveys to obtain data on the structure of the upper part of the section (high frequency resolution) of rocks to issue recommendations for the construction of engineering structures, primarily in the areas of crossings over water obstacles. Effect: improve the accuracy of selecting blocks of rocks with different resistance on the parts of the crossings over water obstacles. The inventive method includes a vertical electric sounding (VES), circular Mikroelektronika sensing, validation of measurements and the construction of a geoelectric section. Before VES conduct electrical profiling for each of the alternatives in the area of research. VES carried out perpendicular to the target crossing the water obstacle. Perform on both sides of the water obstacles circular Mikroelektronika sensing, followed by VES bottom of water hazards. Then on the area of research performed along the competing variants circular Mikroelektronika sensing. The data and build the geoelectric section. 1 C.p. f-crystals, 1 Il. The invention relates to the engineering-geological surveys for the floor is hanicheskih structures, primarily in the areas of crossings over water obstacles.The known method engineering and geological surveys using GPR vertical electrical sounding (VES), allowing to obtain the necessary amount of information about the studied section in normal conditions (the“Prospecting”. Handbook of Geophysics. - M.: Nedra, 1980, S. 64-71, 82-106).However, when working in areas of crossings over water obstacles specified method gives large errors in obtaining information about the studied section.There is also known a method of carrying out engineering geological surveys, including vertical electric sounding, cross VES (LSC) to determine the depth location of the surface layers at shallow depths studies (“Prospecting”. Handbook of Geophysics. - M.: Nedra, 1980, S. 466-468).But this method doesn't allow the cut with sufficient accuracy lots of rocks with different resistance on the parts of the crossings over water obstacles.Closest to the proposed by its technical essence is a way of carrying out of engineering and geological surveys, including vertical electric sounding (VES), the unwinding of the line AB and MN, cresa (RF Patent No. 2080626, G 01 V 3/04, published. 27.05.97, bull. No. 15).This method also does not allow you to highlight in the context with sufficient accuracy lots of rocks with different resistance on the parts of the crossings over water obstacles.The task to be solved by the invention, is to improve the accuracy of selecting blocks of rocks with different resistance on the parts of the crossings over water obstacles.The solution of this problem is achieved in that in the method of conducting geotechnical investigations, including vertical electric sounding, the unwinding of the lines AB and MN, circular Mikroelektronika sensing measurements and the construction of a geoelectric section, before unwinding of the lines AB and MN carried out the electrical profiling for each of the alternatives in the area of research. Carry out the unwinding of the lines AB and MN perpendicular to the target crossing the water obstacle. Perform: on both sides of the water obstacles circular Mikroelektronika sensing, followed by VES bottom of water hazards. Then on the area of research performed along the competing variants circular Mikroelektronika sensing and the data obtained are building resistivity RA is the target crossing the water obstacle zones of different size (high and/or low) resistance, meet certain tectonic conditions of occurrence of the rocks.With the aim of identifying areas of change in the intensity of the electric resistance as at different depths (levels), and throughout the length of the competing variants electrical profiling is desirable to perform not less than duchesneau (mnogorazemny) installation.The implementation of the unwinding of the lines AB and MN is perpendicular to the line of crossing of water obstacles helps to avoid errors in the measurement of electrical resistivity of rocks associated with surface irregularities in the area of research and slope of the land surface.Execution on both sides of the water obstacles circular Mikroelektronika sounding sets the degree and the predominant direction of horizontal heterogeneity of the section.The VES bottom water hazards is to determine the lithological composition of sediments.And execution in the area of research along competing options (target crossing water obstacles) additional Mikroelektronika soundings allows you to evaluate the power and lithological composition of the sediments.On the basis of the received data is a forecast about is illustrated in the drawing and is implemented as follows.Competing options 1 on the area of study 2 conduct an electrical profiling install not less than duchesneau (not shown).According to the obtained results choose point 3 vertical electrical sounding, which carry out the unwinding of the lines AB and MN, respectively 4 and 5.The unwinding of the lines 4 and 5 is carried out perpendicular to the line of passage 6 through the water obstacle 7.Perform on both sides of the water obstacles 7 circular Mikroelektronika sensing Kumquat (AB/250 m) to highlight the area and volume plots of rocks with different resistance.Then produce VES bottom 8 water hazards 7 (if AB50 m) with floating or bottom installation 9.Then on the area of study 2 along competing options 1 perform circular Mikroelektronika sensing.According to a study in construct charts and tables that summarize information about the distribution of the electric resistance on the surface and in the inner points of the studied geoelectric section.And on the basis of the obtained data about the changing parameters of the studied section forecast of laying the foundations for the construction of the La inventions1. The method of carrying out engineering-geological researches, mainly in the areas of crossings over water obstacles, including vertical electric sounding (VES), circular Mikroelektronika sensing and the construction of a geoelectric section, characterized in that in the area of research conduct electrical profiling for each of the alternatives, perform vertical electric sounding perpendicular to the target crossing the water obstacle, carried out on both sides of the water obstacles circular Mikroelektronika sensing, followed by VES bottom water obstacles, then the area of research performed along the competing variants circular Mikroelektronika sensing and the data obtained are building geoelectric section.2. The method according to p. 1, characterized in that the electrical profiling conducted not less than duchesneau installation.
FIELD: geophysical prospecting by electric means by the method of induced polarization.
SUBSTANCE: the device has an exciting field forming unit and a signal measurement unit. The exciting field forming unit has a ship generator, switch forming bipolar DC square pulses, generating plant and a ballast device. The signal measurement unit has a receiving multi-electrode line, resistivimeter, multi-channel measuring device, ship echo sounder, Global Position System receiving indicator and a signal processor. According to the claimed method, the research of the geological medium along the observation outline is carried out by excitation of periodic alternating current pulses and determination of geoelectric medium parameters, geoelectric sections are constructed, a conclusion is made on the presence of a deposit of hydrocarbons according to the exposed anomalies of conduction and the parameters of induced polarization.
EFFECT: enhanced reliability of the research results.
8 cl, 5 dwg
FIELD: physics; geophysics.
SUBSTANCE: current pulse is excited in the medium under investigation, and parameters of its induced polarisation are defined. Geoelectric section is generated to make a conclusion about the presence of hydrocarbon fields on the basis of abnormal manifestations of induced polarisation parameters. At that, electromagnetic and seismic waves are excited simultaneously or with a time shift. To excite the said waves unipolar rectangular impulses of direct current are generated, their absolute and relative duration depending on parameters of medium under investigation. In the beginning of timing pulse electric field is measured simultaneously at measuring probe groups of two detector lines towed at different depth. Besides, detector line depth and hydroacoustic pressure of seismic source are measured. Also a device is offered, which includes pulse generator, capacitor charging unit, power generator, bank of capacitors, switchboard, seismic emitter, transmitter/receiver line, receiver line, multi-channel gauge, echo-sounder, GPS satellite navigation receiver, signal processor.
EFFECT: higher reliability of research results.
18 cl, 6 dwg
FIELD: geoelectrical prospecting.
SUBSTANCE: invention relates to geoelectrical prospecting by the electrical resistance method. The method uses two fixed supplying grounding circuits, the first of them being located in practical infinity, the other one along with two fixed reception grounding circuits being arranged nearby the observation profile, two additional movable grounding circuits located at equal distance from the second supplying grounding circuit. In measurements, in every position of the movable grounding circuits, the latter are connected in turns to a power source or an instrument. On connecting them to the power source, a voltage drop between the fixed reception grounding circuits is measured. On connecting them to instrument and measuring the voltage drop between them, the fixed supplying grounding circuits are connected to electric power source. The aforesaid operations are effected for all preset positions of the movable grounding circuits. Proceeding the measurement results, sections of apparent electrical resistance and voltage drop are plotted to estimate the availability of geoelectrical irregularities in the section.
EFFECT: higher efficiency of revealing geoelectrical irregularities and lower ambiguity in experimental data interpretation.
SUBSTANCE: current is cutoff to soil through two point sources. The first source is placed close by vertical interface, and the second is taken to infinity. Position of one equipotential line of electric field is detected. Measuring electrodes is mounted by tangent to equipotential line symmetrically to tangency point of ray lined from auxiliary point presenting mirror reflection of point source relative to interface with specified equipotential. Besides, measuring electrodes can be placed by line, perpendicular to interface symmetrically to power supply provided close by interface. Near to interface there is compensatory point source with current value fixed by parity where I0, Ik are currents from the first and compensatory sources, ΔΨ1MN is differential of the space function that determinates position of measuring electrodes relative to the first source, ΔΨ2MN is differential of space function that determinates position of measuring electrodes relative to compensatory source. Measuring electrodes voltage indicates time variations of resistivity.
EFFECT: simplified positioning of electrical survey unit and improved measurement accuracy.
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
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.
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
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