The way the search of oil and gas in the offshore areas and wetlands

 

(57) Abstract:

The method is intended for use when carrying out exploration work in the oil and gas industry in the study wetlands and shelf. The method is carried out by the two-stage geochemical surveys of the study area and subsequent survey. Both steps are carried out on the snow and ice. At the first stage determines the presence of a zone or zones of hydrocarbon anomalies. For this purpose, the study area break a regular rectangular grid. At the points of intersection of the grid make sampling, and then spend their laboratory analysis aimed at determining the content of hydrocarbons, which define the contour line of each of the identified hydrocarbon anomalies. In the second stage, specify the border location of each zone by sampling in grid cells adjacent to the detected contour lines. The cells are divided into four approximately equal parts. Identified anomalies investigate seismic methods for determining the spatial position of oil and gas deposits and Refine their boundaries. The resulting data is used to determine points hall of the person, reducing the cost of exploration.

The invention relates to the field of exploration in the oil and gas industry in the study of wetlands and/or shelf and is aimed at reducing their costs and increasing efficiency through rational allocation of prospecting, exploration and subsequent production wells for oil and gas.

Known exploration for oil and gas exploration by seismic. While at a pre-selected network profiles produce seismic surveys within the entire study area. By processing and interpretation of seismic data in the geological cross section of the public looking for traps that may be associated deposits of oil and gas, and predict the presence of deposits (see Russian Federation patent 2078356 C1 IPC 7 G 01 V 9/00, 1/00, 27.04.1997).

However, this method searches of oil and gas roads, as it requires drilling and seismic surveys, using a seismic survey can be successfully found only traps structural type and with a fairly high degree of confidence to predict the presence of deposits of unique and large the major difficulties as the influence of these fields on the wave picture is comparable or significantly below the influence of geological factors. In addition, in nature there are deposits associated with non-structural traps of the type that the method of seismic prospecting in most cases cannot detect. In this regard, by seismic data have to drill a large number of wells, the peculiarities of the study area, such as a shelf or strongly wetlands, in the absence of passable roads, can make a seismic survey is very difficult and expensive.

Known geochemical methods of prospecting for oil and gas, which are methods of searching and reliably assess the possibility of the availability of deposits in the subsurface of the study area (see Russian Federation patent 2039369 C1 IPC 7 G 01 V 9/00, 09.07.1995).

World experience shows that the negative assessment of the petroleum potential of geochemical methods is confirmed by the results of drilling at 100%, and positive in 60-80%.

The lack of geochemical methods is that they are unlike seismic can't show the geological structure of the territory, but only assess the prospects of the availability of deposits in the depths of Senate and gas adopted as the middle analogue (prototype), which in the study area spend gas-geochemical survey through the study of gases adsorbed on the clay matrix, the results of which reveal zones of hydrocarbon anomalies, and then on the sites of a square profile within the identified hydrocarbon anomalies with output in normal field carry out electrical work, receive specialized graphics EMF, which is judged on the parameters of the reservoir at a depth from the surface geochemical anomalies to the desired Deposit (see Russian Federation patent 2102781 C1 IPC 7 G 01 V 11/00, 20.01.1998).

However, using this method you can not search for oil and gas in the waters offshore, or in much the wetland area to get the precise boundaries of the deposits.

Object of the invention is the provision of opportunities for exploration of oil and gas in the waters of the shelf and/or in highly wetland area with harsh winters, such as in Western Siberia, as well as reducing the cost of prospecting and improving the accuracy of locating oil and gas deposits.

These technical results are achieved due to the fact that the method searches Meer the waters of the shelf and/or wetland area, determine the zone or zones of hydrocarbon anomalies and subsequent screening for the presence of oil and gas deposits and clarify their positions and boundaries. Geochemical survey carried out on ice and/or snow in two stages, the first stage of a zone or zones of hydrocarbon anomalies determined by sampling of ice and/or snow on the content of trace hydrocarbons in the intersections of a regular rectangular grid, which divide the study area, and the distance between grid lines along the strike of the structural elements select equal to from 800 to 1200 m, and transverse to the extension of from 400 to 600 m, then conduct laboratory analysis and its results build the contour line of each of the identified zones of anomalies, and at the second stage clarify the boundaries of the location of each zone anomalies by sampling in grid cells adjacent to the detected contour lines, and the data cell is divided into sections with lines spaced from 400 to 600 m along strike and 200 to 300 m across strike, and the selection is performed at the intersection of the lines, and laboratory analysis of each sample during both phases carried out using gas chromatogra zone or zones of hydrocarbon anomalies to determine the spatial position of oil and gas reservoirs and identify their boundaries produced by seismic exploration.

To exclude the possibility of contamination of samples pairs technical petroleum products glass containers transported to the place of field work closed with metal covers and hermetically Packed in polyethylene bags. Vehicles used in the sampling of ice and/or snow (snowmobile "Buran"), stop, just not less than 25 m to the first sampling points on the grid (the profile). To move around the grid lines you can use skates and skis. The selected samples are sent in geochemical laboratory daily. To prevent distortion of the results due to the destruction of hydrocarbons by microorganisms shelf life of samples limit 5 days.

With the aim of reducing the cost of the works in the samples of ice and/or snow only determine the content of sorbed hydrocarbons.

As a significant part of the study area can be covered with swamps, data about the contents in the samples of methane and ethane from the process to exclude.

Experienced geochemical studies have shown that the content of hydrocarbons in ice and/or snow cover 1-2 orders of magnitude higher than the sensitivity tx2">

It should be noted that for the geochemical survey on the ice and/or snow cover is guaranteed by the availability of the entire study area, in winter conditions, the oxidation processes are practically absent, the content of hydrocarbons in ice or in snow cover higher than their content in the surface sediments and surface waters, thus increasing the reliability of research results. For the geochemical survey on the ice and/or snow is not observed displacement of hydrocarbon anomalies in the direction of surface water runoff, which can lead to a distortion of the true picture of the distribution of hydrocarbons and to errors in the interpretation of the results, and when conducting searches on the shelf at depths of up to 12 meters in sampling points additionally using geological drill taking the bottom (sludge), which allows to increase the reliability of the research.

Reliably identified are only hydrocarbon anomaly based at least three points of sampling.

Seismic surveys in the waters of the shelf and in the wetland area more convenient to hold in the winter time and get more accurate information on the correctly place to search and exploration drilling and subsequent production well, reducing total cost of exploration by 20-30% with a simultaneous increase their effectiveness.

The method searches the field of oil and gas in the offshore areas and wetlands by conducting geochemical surveys of the study area, determine the zone or zones of hydrocarbon anomalies and subsequent screening for the presence of oil and gas deposits and to clarify their boundaries, characterized in that the geochemical survey carried out on the snow, ice shelf and the wetland area in two stages, the first stage of a zone or zones of hydrocarbon anomalies determined by sampling of snow and ice on the content of trace hydrocarbons in the intersections of a regular rectangular grid, which divide the study area, moreover, the distance between grid lines along the strike of the structural elements select equal to from 800 to 1200 m, and transverse to the extension of from 400 to 600 m, then conduct laboratory analysis and its results build the contour line of each of the identified zones of anomalies, and the second stage clarify the boundaries of the location of each zone anomalies by sampling in grid cells adjacent to the detected contour lines, and the data cle who eats stretch, and the selection is performed at the intersection of the lines, and laboratory analysis of each sample of snow and ice during both stages is carried out using a gas chromatograph with a resolution of the propane is not above 1x10-11g/s before the expiration of 5 days from the time of its selection, and exploration of the zone or zones of hydrocarbon anomalies to clarify the spatial position and boundaries of hydrocarbon deposits produced by seismic exploration.

 

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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

FIELD: geology, particularly to predict aerial extent and localization of metal, non-metal and fuel deposits of any genesis and age.

SUBSTANCE: method involves discovering geological structures and determining perspective zones for further deposit prospecting. In the case of ore deposit prediction above perspective zones are determined in low-order dome and composite type structures allied with crystal magma chambers and located over faults of different orders or in areas in which faults of one or several classes intersect. In the case of gravel deposit prediction the zones are determined in area located near ore deposits in neighboring low-order depression structures. In the case of oil and gas reservoir prediction the zones are prospected in all medium-order structures along radial, ring or oval fault areas and along super-deep ring or oval fault areas in zones in which crystal magma chambers are absent.

EFFECT: increased efficiency of aerial deposit extend and age prediction.

2 dwg

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