Mobile self-contained underwater seismic-hydroacoustic station for exploration of hydrocarbons on water area of arctic shelf
FIELD: physics; geophysics.
SUBSTANCE: invention relates to devices for seismic exploration of hydrocarbon deposits on the water area of the arctic shelf. The mobile self-contained underwater seismic-hydroacoustic station for exploration of hydrocarbons on the water area of the arctic shelf has a hard, streamlined housing, a power plant, a motor, a gyroscope, a distance measuring device, an echo sounder, a depth sensor, a hydroacoustic beacon signal locator, buoyancy control means and an on-board computer with a program device for controlling movement of the station from one point on the sea to another, hovering, sinking to the bottom, raising from the bottom to a given depth and onto the sea surface.
EFFECT: designing a mobile underwater self-contained seismic-hydroacoustic station for exploration of hydrocarbons, capable of independently moving according to a given program to investigated points on the sea, hovering over said points, sinking to the bottom and raising from the bottom to a given depth while simultaneously reducing self-generated seismic-hydroacoustic noise.
The present invention relates to a device for prospecting of hydrocarbon deposits on the Arctic shelf.
Currently developing device of seismic exploration using non-explosive sources of seismic energy. This device is intended for the reception of microseisms of the seabed, which carry useful information about the deep structure of the seabed, including information about the presence of hydrocarbon deposits.
A device for seismic exploration of hydrocarbons, consisting of bottom stations with geophones and scuba apparatus, alternately podplyvali to them and collect from them information on the hydroacoustic channel (Svemirskoj. On the application of Autonomous unmanned underwater vehicles technology total bottom seismic. // Proceedings of the 4th all-Russian scientific-technical conference "Technical problems of development of the World ocean", Section 2, 2011, Vladivostok, s-224).
The disadvantage of this solution is that by this method of exploration in addition to the submersible must be installed on the bottom of the large number of bottom stations (up to 220 units)to which the sub alternately come and polls. This arrangement of devices for seismic increases the cost of the seismic survey because of the need to install a large Koli is esta expensive seismic stations and the complexity of their installation and lifting, especially in areas with a muddy bottom and in the presence of the ice cover. This device does not provide for its installation in the bottom layer of the sea.
Another analog is the invention according to the patent of Russian Federation №2438149 "Autonomous bottom stations for seismic observations". The station consists of a sealed enclosure, bottom geophone sensor spatial orientation, beacon, ballast, NC ballast, analog amplifiers and filters low frequency, block the exact time and digital recorder.
The disadvantage of this technical solution to be used in Arctic conditions is the difficulty of installation of seismic stations on the bottom of the sea under the ice cover and, especially, permutations of seismic stations in the other measurement points on the bottom with powerful ice cover. Also not provided for the installation of seismic stations in the bottom layer of the sea.
The closest analogue, that is, the prototype is the invention according to the patent of Russian Federation №2435180 Underwater geophysical station".
The essence of this invention lies in the fact that the submarine geophysical station has a sealed housing made of high strength aluminum alloy with a protective corrosion-resistant coating, seismogenic, means of recording and storing information.
The disadvantage of the prototype are previously mentioned the difficulties of installation and rearrangement of bottom stations at other points on the bottom of the sea with powerful ice cover. It is also not possible to add in the bottom layer of the sea.
Note that currently there is no information about the stations, able to move independently to measure from one point of the sea to another point, to hang over her, and then to lie on the ground of the sea bottom and to rise from the bottom to a predetermined depth. Besides the measurements on Board the mobile underwater station is difficult because of interference with the flow. These interference mask microseisms from hydrocarbon and prevent their detection.
The purpose of this invention is to provide a mobile Autonomous underwater seismogeological station of hydrocarbon exploration, able to move independently according to a given program in the study of sea point, hover over them to sink to the bottom and go up from the bottom to a predetermined depth while reducing their own seysmogydroaquistic interference.
This goal is achieved by the fact that mobile Autonomous underwater seysmogidrodinamicheskie station of hydrocarbon exploration in the waters of the Arctic shelf is additionally equipped with a rugged, streamlined, power plant, propeller, gyroscope, fuel gauge path, depth sounder, depth sensor, locator signals sonar beacon, means of regulating the buoyancy and the onboard is a computer software device motion control station from one point of the sea to another, hang on, the descent to the bottom, rise from the bottom to the specified depth and at the surface of the sea.
The combination of these features ensures the achievement of this goal.
The proposed device is illustrated by a drawing, which shows a diagram of a mobile Autonomous underwater seismogeological station, where:
1 - rugged streamlined;
2 - gyro;
3 - meter path;
4 - sounder;
5 - the depth sensor;
6 - Board computer software device management;
7 - seismogenic;
8 - a means of providing buoyancy;
9 - power installation;
10 - mover;
11 - locator signals sonar beacon.
Underwater station depending on ice conditions is delivered with the help of surface or underwater hydro vessel in the area of the first target point and is available in swimming. Possible lowering of the station into the hole with ice.
Underwater station has rugged streamlined (POS.1). Depending on the indications gyro (2)meter path (3), echo sounder (pos.4), depth sensor (5) on-Board computer device (pos.6) provides the following modes of operation: move from one point sea to another, hang, descent to the bottom and rise from the bottom to the specified depth. The field and the test was established, that microseisms of the seabed can be registered by seismographs are not only at the bottom, but in the bottom layer of water. This explains the complex sequence of dimensions: hangs at the descent to the bottom and on the bottom.
To perform these operation modes is selected mover (10), for example an electric motor, and power setting (position 9), for example a battery, and means for regulating the buoyancy (pos.8). Adjusting the buoyancy is in the range from zero buoyancy to negative or positive buoyancy. In hang mode station is moved over together with the water environment, which reduces hydrodynamic interference flow and facilitates the recognition of microseisms from hydrocarbon fields. Seismogenic (pos.7) allows measurement of individual projections of the vector oscillating speed (acceleration, displacement, or derivatives thereof), and all at the same time. In the process hangs and smooth dive to the bottom and when at the bottom of the geophone signals are recorded in digital form.
Further, these data are used in an inpatient treatment center or on Board the vessel when interpreting results to determine the signs of the presence of hydrocarbon deposits.
After completion of measurements of the underwater station returned to the area first examine the second point and the computer sends a signal to switch on the locator signals sonar beacon (11) for detecting beacon (submarine or surface ship or lighthouse, drop from the ice at the point of deployment) and the approach to the lighthouse and the lift station on geophysical vessel or on the ice.
Technical and economic effect is to reduce the complexity and cost exploration equipment, as u mobile station and is a measure of microseisms and does not require additional benthic stations.
Unlike mini-submarine with a crew declared an underwater station has considerably smaller dimensions and considerably lower cost. In unmanned stations eliminated the problem of security people.
Mobile Autonomous underwater seysmogidrodinamicheskie station of hydrocarbon exploration in the waters of the Arctic shelf, consisting of a solid body, geophone, tools, registration and storage of information, distinguish fact that additionally, the station has rugged streamlined, energy-power installation, propeller, gyroscope, measuring path, depth sounder, depth sensor, locator signals sonar beacon, means to control buoyancy and the on-Board computer control device to move the station from one point of the sea to another, hang, descent to the bottom, rise from the bottom to the specified depth and at the surface of the sea.
SUBSTANCE: method involves excitation of elastic vibrations by a vibration source in a well crossing hydraulic fracturing cracks, recording at receiving points at least in one neighbouring well of resonant vibrations emitted with a hydraulic fracturing crack system at excitation in drilling fluid of elastic vibrations, and determination of parameters of the crack system as per resonant vibrations occurring in the cracks. Excitation of vibrations in the well and their recording is performed before and after hydraulic fracturing. Besides, for each fixed source-receiver pair there formed is a difference seismic record of the records received before and after hydraulic fracturing; signals emitted by the crack system are separated on the difference seismic record, and parameters of cracks are determined as per the above signals.
EFFECT: improving reliable determination of spatial orientation of a hydraulic fracturing crack system and its dimensions.
SUBSTANCE: group of inventions includes a method of extracting hydrocarbons from a subsurface region, a method of transforming seismic data paths and a method of determining a near-surface earth model of elastic shear wave propagation velocity based on the seismic data path. The invention employs seismic data, recorded preferably with a plurality of sources and receivers and a two-stage inversion technique. First, variations in surface-wave signals are decomposed (303) into surface-consistent transfer functions, preferably for each source, each receiver and each small region (301) of the surface. The transfer functions for each region are then inverted (308) to determine soil properties or near-surface properties (such as the shear modulus) as a function of depth. The method can solve for the complex multi-mode nature of the surface waves for media with vertical and lateral changes in properties.
EFFECT: avoiding errors and limits in resolution for traditional methods from misidentification of ground roll modes or from assuming laterally uniform soil properties, obtaining elastic soil properties, obtaining elastic properties as a function of depth from surface or depth profile of properties.
22 cl, 15 dwg
FIELD: oil and gas industry.
SUBSTANCE: seismic measurements are carried out by means of a CDP method on the surface area perspective in oil-and-gas-bearing respect. Processing and structural interpretation of seismic data is performed, thus obtaining structural maps of target reflecting horizons. Based on structural maps, additional build-up of two-dimensional networks of target reflecting horizons is performed. As per the received two-dimensional networks of target reflecting horizons and using a trend analysis method, build-up of two-dimensional networks a regional component is performed for each reflecting horizon. A local component is calculated. For cells of the two-dimensional network of the local component the prepared structures are localised for each target reflecting horizon at simultaneous fulfilment of two conditions: first - when the local component is larger than zero, and second - when a zero contour is closed. A sum of local component is defined for all the target reflecting horizons. With that, the local structure is considered to have been prepared for all the target reflecting horizons when the value of sum of local component is larger than zero. For allocated localised structures for each reflecting horizon there calculated is local structure amplitude and local structure surface area. Priority of readiness degree of the structure prepared for prospecting and exploratory oil and gas drilling is determined as per the value of amplitude and surface area of local structure, and namely: the higher the above local structure values, the higher the perspective of prospecting and exploratory oil and gas drilling.
EFFECT: improving geological informativity of geophysical surveys, localisation and ranging of prepared structures as to the perspective at preparation for prospecting and exploratory drilling.
FIELD: radio engineering, communication.
SUBSTANCE: disclosed is a method of detecting voids in the upper section of the earth's crust, involving measurement and detection of acoustic emission on the profile in the 0.01-500 Hz frequency range, with distance between measurement points in accordance with survey scale. Profiling is performed based on natural acoustic noise. Acoustic emission is detected at each point for at least 1 minute; acoustic emission spectra are calculated in 3-10 s in multiple time intervals; the average dominant experimental spectrum Se(f) and the mean-square deviation (σs) of the average from the three-second spectra are found. The theoretical shape of the desired objects is set and theoretical spectra S0(f) thereof are calculated. Resonance frequencies fm are determined from the function Se(f); curves of intensity of the spectral function Se at resonance frequencies fm (m=1, 2, 3) are plotted. Probable boundaries of desired objects on the profile are determined from intensity anomalies indicated by intensity of the spectral function S(fm) on the profile exceeding its average value by +Kσ, and gradients of the function S(fm). Preliminary dimensions and shape of said objects are determined from said boundaries and the given shape. Theoretical spectra are calculated, compared with experimental spectra; the most similar theoretical spectrum is found from the mean-square difference which does not exceed +Kσs (K=1-3) and the selected theoretical spectrum is identified with voids of a given shape and size.
EFFECT: detecting voids without breaching the integrity of the earth's surface.
SUBSTANCE: method involves performing geologic and seismic survey, as well as remote optical gas analysis using remote lidar. During gas analysis, a spectral image of the set of chemical components in the surface layer of the atmosphere is formed. Spatial selection of the spectral image of the area on given tracer substances is performed. The detected gas components are compared with the composition of the reference mixture of hydrocarbon components which corresponds to the geographical position of the area and the deposit. The area is mapped with spatial differentiation on the relief of the obtained spectral image of the probed area. The spectral image of the region of the authentic hydrocarbon deposit is selected on the map. A family of points with the measured concentration of heavy hydrocarbons is determined.
EFFECT: high accuracy of searching for hydrocarbons, low cost of search operations.
SUBSTANCE: according to the disclosed method, observation lines during land seismic survey have to be given on straight sections of the projection of a curvilinear well bore on the day surface.
EFFECT: high accuracy of determining the structural form of geological objects and longer tracking thereof during combined interpretation of well and land seismic survey data.
SUBSTANCE: group of inventions discloses an apparatus, system and method for seismic investigation of an underground structure by displaying seismic image data, which involves calculating, based on a set of wide azimuth data, a set of discrete data associated with an image function at a point of the seismic image. The set of discrete data can be transformed into a continuous curvilinear three-dimensional surface. The displayed set of data can be projected on a continuous flat surface. The projected data can be displayed in form of a flat disc. A plurality of continuous flat surfaces, each representing a single point of the image, can be collected to form a three-dimensional body which is a seismogram of points of the image. The three-dimensional body can be displayed.
EFFECT: high accuracy of geophysical detection during survey and extraction of oil and gas.
25 cl, 9 dwg
SUBSTANCE: seismic exploration system includes a seismic vibrator capable of exciting signals of different spectral composition with a system for generating control signals and a system for controlling the excited probing signals, a seismic station capable of correlating vibration records and converting the vibration records to impulse seismograms with a system for generating correlation signals and a system for determining parameters of control signals and means of communication between the seismic station (seismic vibrator) and the seismic vibrator (seismic station). The output of the system for controlling excited probing signals is connected through the means of communication between the seismic vibrator and the seismic station to the input of the system for generating correlation signals. The output of the system for determining parameters of control signals is connected through the means of communication between the seismic station and the seismic vibrator to the input of the system for generating control signals.
EFFECT: high accuracy and information value of seismic exploration.
SUBSTANCE: in the investigated territory, spatial distribution of flux density of total seismic energy characterising background intensity of its seismic activity is determined. At least one electromagnetic pulse emitter is placed on the investigated territory. The earth's crust on the investigated territory is exposed to electromagnetic pulses. Spatial distribution of flux density of total seismic energy during exposure is determined. A region preparing for an earthquake is selected. The rate of seismotectonic deformation of the selected region during exposure of the earth's crust is determined. Total seismotectonic deformation of the selected region is determined. The magnitude of the predicted earthquake is calculated.
EFFECT: high reliability of prediction.
SUBSTANCE: device includes: a hollow housing rigidly mounted in the bottom recess of an underwater floating vehicle, the top part of said housing having an axial hole for passage of a piston rod for cleaning the implosive chamber. The chamber is formed by an axial hole in the housing, a casing rigidly mounted in the bottom part of the housing and a bottom cover rigidly mounted in the bottom part of the casing. Windows of the chamber are made in the bottom part of the housing. The cleaning piston is composite. Its top part is rigidly mounted and tightly connected to a rod. The bottom part of the piston is mounted by a hollow sliding piece which is sealed with respect to the inner hole of the top part of the piston, the sliding piece being limited in back and forth movement by an inner shoulder in the hole of the top part of the piston. A spring-loaded clamp is rigidly attached to the bottom part of the piston inside a through-hole with possibility of interaction with a support on an axial cavity in a head which is freely mounted in the bottom part of the chamber. The axial hole of the housing, where the piston moves freely, has two rows of drainage radial holes linking it with the surrounding space: a top row at the top end of the hole, a bottom row above the windows themselves. The implosive chamber is covered at the bottom by a blind bottom with a check valve which allows liquid into the surrounding space, and has four longitudinal windows in the top part. The chamber is covered on its entire length by a reflector which forms a passage annular section whose area is not less than the cross-sectional area of the piston. The reflector is rigidly attached to a depression on the housing above the windows. The movable connection of the cleaning piston and the housing is sealed. The top part of the rod is rigidly attached to the bottom bearing of a long toggle link which is turned through a flexible coupling by a gear motor. A head is freely mounted inside the chamber under the cleaning piston with a large radial gap. The windows of the chamber are in an open position when all parts of the piston are in uppermost position.
EFFECT: achieving a continuous process of transmitting seismic pulses with the required frequency in the immediate vicinity of the bottom during underwater seismic profiling.
FIELD: seismic prospecting.
SUBSTANCE: method can be applied at prospecting of oil and gas pools as in sedimentary and in metamorphic and crystal rocks. Seismic waves induced by seismic standard source close to surface are registered. Wave fields are formed from expected objects of reflection, diffraction and dissipation and parameters of processing are chosen in such a manner to provide better selection of modeled objects on the error background. Received parameters are used for processing real data and selecting real objects. Shapes of objects of dissipation are presented in form of maps and sectional views.
EFFECT: increased level of valid signal.
FIELD: electro-seismic prospecting.
SUBSTANCE: signal of source are subject to correlation with reference signals chosen to minimize side lobes of correlation function. To form fragment of prolonged source signal having minimal side lobes of correlation function sequence of which is specified by binary code, the circuit with frequency of 60GHz is used. Preferable binary codes are based on complimentary Golay pair and sequences of shift registers with maximal length.
EFFECT: improved efficiency.
21 cl, 8 dwg
FIELD: seismic prospecting.
SUBSTANCE: method comprises recording seismic vibrations of the Earth in a given range, generating and recording additional seismic vibrations, extracting information signal, which is a signal from the productive pool, analyzing the spectra of the data obtained, and determining presence or absence of hydrocarbons and position of productive hydrocarbon pools.
EFFECT: enhanced accuracy and reliability of prospecting.
19 cl, 4 dwg
FIELD: seismic prospecting.
SUBSTANCE: method can be used for searching non-uniformities. While conducting seismic prospecting the radiated wave receivers and transmitters are located outside inspected rock mass at two adjacent faces of tested volume of rock at the squares having radius equal or 5 times longer than wavelength in tested volume of rocks. Tested mass is a divided to cubic unit having heights of faces no longer than Ѕ wavelength of radiated wave specified by depth of testing. Rock mass is subject to radiographic test at two orthogonal directions. Radiated waves are focused into center of any cubic unit and waves at receivers are subject to co-phase summation from center of any cubic unit for any radiation of seismic waves. Energy of waves from any center is measured. Volumetric image of local diffracting object in rock mass is achieved from maximal values of energy from any center. When getting local volumetric image of object the calculations are repeated for speed values increasing subsequently depending on speed achieved during seismic well logging. Speed values at which centers of image of object coincide are assumed to be truthful and position of object received at that speed is assumed to be truthful as well. Image of object is put to coincidence from two directions for separate cross-sections. That image is assumed as truthful. Units are put together from which units the energy has maximal value at two images.
EFFECT: improved precision of determination and shape of diffracting object.
FIELD: seismic reconnaissance.
SUBSTANCE: intervals with ramp gradients of speed of spreading of fluctuations are picked out in a geological section. Parameters of interferential system of excitation are determined for these intervals of the section. The parameters include linear dimensions of the base of a group of oscillators, the distance between oscillators and their number, frequency structure and duration of sweep. Oscillators are located at fixed distances one from another. Elastic vibrations of the group of oscillators are excited in series. Elastic vibrations received for each interval of the section at fixed number of oscillators of elastic vibrations are registered. At completion of the full cycle of observations at one placing of oscillators the group of oscillators is moved one step further. This step is equal to the distance between oscillators and the cycle of observation is repeated fulfilling observations in accordance of the whole profile with the duration of recording exceeding intervals of registration of waves from the base of processing intervals. Groups of seismograms are made and compiled. Summary seismograms of elastic vibrations are formed. On the basis of received results makeshift sections are built.
EFFECT: increases effectiveness.
FIELD: seismic prospecting.
SUBSTANCE: method can be used when prospecting oil and gas fields. Method is based upon forming of random wave field (microseism) on the base of microseisms received during seismic prospecting works at profile and area observations. Wave field is formed by creating series of time fields composed by totality of routes being equally distant from explosion site for areas, which are free of recording of regular waves, and summary time fields composed by seismograms of multiple overlapping integrated by the same point of reception. Received wave fields are subject filter filtration and spectral analysis. Parts of abnormal values of low-frequency component and specific energy of the component in total random wave field is determined. Gradients of spectra are determined and maps of those parameters distributed along the area are built. If drilled holes are available, correlation links of c calculated parameters are found and those data is used in complex interpretation of seismic prospecting works of materials or for expert evaluation and specification of given before drilling recommendations for search or survey holes.
EFFECT: simplified technology.
FIELD: the invention refers to the field of seismic research and may be used at studying seismic field of natural or artificial origin.
SUBSTANCE: notified mode of seismic monitoring, in the algorithm of which an operation of calculating energy of seismic waves is additionally introduced with following registration of calculation results in the point of measuring for some beforehand installed interval of time chosen in dependence of frequency band of registered signals and prolongation of fading of a seismic wave to the background level at impulse impact. For carrying-out this function an additional energy calculating block is introduced in the field seismic registering equipment.
EFFECT: increases efficiency of transmission of seismic data to the collecting and processing post and increases duration of work of field registering apparatus in autonomous regime.
3 cl, 5 dwg
FIELD: the invention refers to geophysical methods of researching of oil wells and designed for evaluation of dominant saturation of a collector with oil or water.
SUBSTANCE: measurements of natural geo acoustic signals are determined along the axle of a well cased with a column in three or more given ranges of frequencies. The value of the terms ratio of amplitudes of signals registered in each given frequency range is determined in relation to the amplitude of the signal registered in the range of the least frequencies. The character of saturation of the plast-collectors is determined is evaluated according to an established value of relation of the amplitudes of signals registered in ranges of frequencies to the signals of the low-frequency range, equal 0,8. The exceeding of this value indicates on the dominant saturation of the plast-collector with oil.
EFFECT: increases efficiency of determination of the character of saturation of collectors in wells cased with tubes.
SUBSTANCE: in accordance to the method, dispersive curve of micro-seismic waves is determined preliminarily. Wave lengths λ are determined as well as frequency spectrum of micro-seismic signal on basis of analysis of apparent speeds, wherein it consists of Raleigh waves. Seismic indicators are positioned across researched territory in such a way, that distance between them was not more than half the shortest length of Raleigh wave. Then, amplitude difference of measuring channels of seismic indicators is determined within frequencies band of micro-seismic signal. Micro-seismic signal is registered by no less than two seismic stations, one of which is mounted in stationary manner in the central portion of researched territory, and the rest are moving across researched territory. Accumulation of power spectrum of micro-seismic signal is performed in each measurement point during time, enough to reach stationary spectrum. Spatial variations spectrum of micro-seismic signal is connected for each measurements point. Maps of amplitude variations of micro-seismic signal are built for each spectrum frequency of spatial variations. Alignment of each received map is performed to appropriate depth H.
EFFECT: increased depth capacity of exploration seismology with simultaneous increase in trustworthiness of results.
FIELD: the invention refers to seismic prospecting precisely to modes of carrying seismic prospecting works with application of non-explosive surface sources.
SUBSTANCE: the mode includes separation of a geological cut on depth floors, computation for each floor and location on the terrain of a system of reception of seismic signals distinguishing between themselves with a pitch of receiving channels, excitation of waves by sources, reception and registration of the wave field. New in it is that according to the results of computation a system of reception of seismic signals is picked up. The system is tuned on the depth floor rendering the outmost distorting influence on the wave field of the depth floors lying below and the receiving channels in this system and the sources are located on the terrain with an identical pitch. At that the excitation of waves is made at least by two seances . In one of them the excitation of waves is made by all sources simultaneously and in the other seance the excitation of waves is made successively with each source.
EFFECT: increases efficiency and accuracy of prospecting works.