Method of mapping magnetic anomalies-indicators of hydrocarbon deposits

FIELD: data processing.

SUBSTANCE: invention relates to geophysics and can be used for mapping magnetic anomalies-indicators of hydrocarbon deposits. Magnetic anomalies are detected from high-accuracy aeromagnetic survey data. Aerogravimetric survey is carried out. Gravitational anomalies are recalculated into pseudomagnetic anomalies. Pseudomagnetic anomalies are subtracted from magnetic anomalies. Magnetic anomalies-indicators of hydrocarbon deposits are mapped from obtained difference.

EFFECT: high accuracy of mapping.

1 cl

 



 

Same patents:

FIELD: measurement equipment.

SUBSTANCE: method of processing of measured data of a potential field in aviation or marine surveys of the potential field includes identification of an array of field mapping parameters for field mapping and introduction of potential field data into the processor. Measured data of the potential field contains data that identify multiple measurements of the potential field, each with the appropriate position of measurement and time of measurement. The array of field mapping parameters is identified using a model containing a combination of a spatial part displaying spatial variation of the specified potential field, and a time area displaying time noise in the specified measured data of the potential field. Besides, the specified identification includes adaptation of measured data of the potential field both to spatial and time parts of the specified model.

EFFECT: problem of low-frequency noise in process of board survey of a potential field is solved.

27 cl, 5 dwg

FIELD: physics.

SUBSTANCE: multilevel gravitational field analytical model is constructed in form of an approximation structure from point sources. Additional information on the gravitational field used is data on the topography of the observation surface and data on anomalous gravitational field on the working surface and the bordering region from materials of different-scale investigations. Coefficients (mass) in equations for given functions of coordinates of point sources are determined such that the analytical model field coincides with the given measured field with the required accuracy. Further, gravitational field transformants are calculated by applying various transformation operators of the sourcewise function to all equations of point sources in the approximation structure followed by additive superimposing of the calculated transformant levels. The multilevel gravitational field model meant for calculating the transformant has dimensions which are greater than the area of analysis.

EFFECT: high reliability of accounting for the effect of side sources, accurate values of any derivatives of anomalous gravitational potential can be obtained with minimum expenses.

3 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.

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. In inter-well space seismic prospecting operations are performed by three-dimensional longitudinal waves according to deep point method. 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 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 coefficients of oil productiveness 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. Optimal volumetric spectral seismic attribute is selected with greatest mutual correlation coefficient. Regression dependencies of optimal spectral seismic attribute are built, or same for complex attribute, with value s of hydraulic conductivity and oil-productiveness coefficient of porous collectors 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 cube and its following recalculation according to regression dependencies to hydraulic conductivity cubes and oil productiveness cubes.

EFFECT: higher reliability, higher precision.

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. In inter-well space seismic-prospecting operations are performed in longitudinal waves according to deep point method. On basis of drilling and geophysical research data standard modeling seismic and well spectral-time samples of oil-productive cracked carbonate collectors and their spectral-time attributes are determined. On basis of three-dimensional seismic prospecting data in area of wells, standard experimental spectral-time images of oil-productive cracked carbonate collectors are determined as well as their volumetric spectral seismic attributes on basis of use of spectral-time analysis of three-dimensional seismic prospecting data in goal recording range and numeric estimation of its results. Mutual correlation of specific integral capacity of cracked carbonate collectors, hydraulic conductivity and oil productiveness is performed on basis of drilling data and geophysical researches of wells with standard modeling seismic, well spectral-time and volumetric spectral seismic attributes in zone of well. Optimal volumetric spectral seismic attributes are selected with greatest value of mutual correlation coefficients. Regression dependencies of optimal standard volumetric spectral seismic attributes are built, or complex attribute, with depth-specific integral capacity of cracked carbonate collectors, their hydraulic conductivity and oil productiveness on basis of drilling and geophysical well research data are built. Along all tracks of seismic time cube in goal range of recording spectral-time analysis is performed and its numeric spectral-time parameterization on basis of optimal volumetric spectral seismic attributes and their following recalculation on basis of set regression dependencies to cubes of integral depth-specific capacity, hydraulic conductivity and oil productiveness is performed as well.

EFFECT: higher reliability, higher precision, higher efficiency.

FIELD: oil and gas industry.

SUBSTANCE: method includes performing three-dimensional seismic operations, drilling wells with extracting of core, electric, radioactive, acoustic and seismic logging, testing of wells. According to data from drilling and geophysical well research type of geological cross-section of target oil-gas productive deposits is determined. According to data from acoustic, seismic and radioactive logging, laboratory research of core, rigidity models of target deposits are set, synthetic seismic routes are calculated, which are used to perform spectral-temporal analysis and standard model seismic spectral-temporal images of oil-gas deposits are also determined. On basis of data of geophysical wells research - acoustic, electric, radioactive logging - well (vertical) standard spectral-temporal images of target range are determined by spectral-temporal analysis of well geophysical research curves. According to three-dimensional seismic operations data in well zone standard experimental spectral-temporal images are determined for oil-gas productive and other types of geological cross-section on basis of use of spectral-temporal analysis of seismic operations data in target recording range. Numeric estimation of model, well and experimental spectral-temporal images is performed. Model, well and spectral-temporal attributes and experimental volumetric spectral seismic attributes should correlate mutually with mutual correlation coefficient more than 0.75. Greatest mutual correlation coefficients are used to select optimal volumetric spectral seismic attributes. Along all routes of seismic temporal cube in target range of recording spectral-temporal analysis is performed and its numeric spectral-energetic parameterization by frequency and time with construction of cubes for optimal volumetric spectral seismic attributes or complex volumetric spectral seismic attribute. Results are compared to standard optimal volumetric seismic spectral attributes and different types of geological cross-section are determined numerically in any point of three-dimensional inter-well space with detection of position of oil-gas productive types of geological cross-section.

EFFECT: higher reliability, higher precision.

FIELD: oil and gas industry.

SUBSTANCE: method includes performing three-dimensional seismic operations, drilling wells with taking of core, electrical, radioactive, acoustic and seismic logging, testing of wells. Seismic operations are performed in three-dimensional inter-well space by longitudinal waves on basis of common deep point method. According to data from drilling and geophysical well research standard model seismic and well spectral-temporal images of cracked argillaceous collectors are determined as well as their spectral-temporal attributes. According to data from three-dimensional seismic operations in zone of wells standard experimental seismic attributes are determined and their volumetric spectral seismic attributes on basis of use of spectral-temporal three-dimensional seismic data analysis in target recording interval and numeric estimation of its results. Following mutual correlation of values of coefficients of capacity differentiation and oil productiveness is performed on basis of data from drilling and geophysical wells research with standard model seismic, well spectral-temporal attributes and volumetric spectral-temporal seismic attributes according to three-dimensional seismic data. Optimal volumetric spectral seismic attributes are selected with greatest mutual correlation coefficients and regressive dependencies of optimal volumetric spectral seismic attributes are built, or of a complex attribute, with values of coefficients of capacity differentiation and oil-productiveness of cracked argillaceous collectors according to drilling data and geophysical well research. Along al routes of seismic temporal cube spectral-temporal analysis is performed and its numeric spectral-temporal parameterization on basis of optimal volumetric spectral seismic attributes, or a complex attribute, with construction of attributes cubes and following recalculation thereof according to regressive dependencies to cubes of coefficients for capacity differentiation and oil productiveness.

EFFECT: higher reliability, higher precision.

FIELD: oil and gas industry.

SUBSTANCE: method includes performing surface three-dimensional seismic operations using 3D longitudinal waves according to common-depth-point method, drilling wells with extraction of core, electric, radioactive, acoustic and seismic logging, testing of wells, research of core. On basis of total data from drilling and geophysical research of wells, and known criteria, presence of collectors, their capacity, penetrability, hydro-conductivity, oil productiveness, level of water-oil contact, position of oil fields, and also presence of correlative connection between capacity, hydro-conductivity and oil productiveness, are detected and/or estimated. According to data from acoustic, seismic and radioactive logging, and laboratory research of core, liquid models of target deposits are constructed, synthetic seismic trajectories are calculated, along which spectral-temporal analysis is performed and model seismic spectral-temporal and acoustic samples of oil-productive collectors are determined, which together form an oil bed. According to data from surface three-dimensional seismic 3D operations and results of common-depth-point method in area of wells experimental seismic spectral-temporal and pseudo-acoustic images of oil bed are determined. Acoustic and pseudo-acoustic images are estimated using bed-average acoustic and pseudo-acoustic speeds within target range of depths and times. Model seismic, well spectral-temporal analysis results and standard optimal specific results, acoustic and pseudo-acoustic speeds are correlated to capacity, hydro-conductivity, oil productiveness of collectors, regressive dependencies are set as well as mutual correlation coefficient. Along all trajectories of seismic temporal cube within target range of seismic record spectral-temporal analysis is performed and pseudo-acoustic conversions with determining of optimal specific results, pseudo-acoustic speeds and construction of cubes of spectral-speed attributes, which are recalculated to cubes of third powers of capacity, hydro-conductivity and oil productiveness of collectors.

EFFECT: higher reliability, higher precision, higher trustworthiness, higher efficiency.

FIELD: prospecting.

SUBSTANCE: method comprises exciting seismic vibration by means of a seismic source, generating simultaneously electric field by means of at least two electrodes, recording seismic vibration at least once when current is supplied to the electrodes and at least once when electric power is not supplied to them, producing the difference of seismic records obtained in the presence and absence of electric field, and detecting anomalous phenomena from the variation of the amplitude of reflected waves of seismic and seismic-electric fields.

EFFECT: enhanced precision and reduced cost of prospecting.

4 cl, 2 dwg

FIELD: oil geology, particularly to determine occurrence depths and relief structure of prospective geological horizons.

SUBSTANCE: method involves performing seismic exploration; drilling wells; determining reflection horizon seam depth on the base of drilling data; obtaining dependence of above seam depth as a function of relief altitude and determining interval velocity of upper non-uniform layer for following subsurface geologic imaging.

EFFECT: increased accuracy.

FIELD: geophysics.

SUBSTANCE: in accordance to method by transformation of excited and registered wave fields, amplitude-frequency and transfer characteristics of deposits of hydrocarbon resources are formed along lateral line and below face of control well, which are used to determine position and depth of oil-gas deposits. After transformation and comparison of frequency characteristics of longitudinal and transverse resilient oscillations, character of saturation and filtering-capacity properties of oil-gas deposits are determined.

EFFECT: higher efficiency, higher trustworthiness.

2 cl, 6 dwg

Up!