1. Processing 2D/3D seismic data of various levels of complexity
Kinematic processing of seismic data using the following approaches:
- construction of the low velocity zone (LVZ) model based on the dispersion spectra of surface waves (the first 50-100 m)
- construction of the LVZ model based on refracted / refracted waves
- embedding check shot velocities
- layer replacement
- embedding the LVZ model in the depth velocity model (DVM) for depth migration and its subsequent refinement/update/fixation
Dynamic processing of seismic data
- estimation of surface-consistent deconvolution operators and amplitude correction after interpolation/regularization (implemented by deriving previously applied operators, the effect is achieved by equalizing the signal component/compensating for random noise during interpolation)
Special processing of seismic data
- joint processing of 2D and 3D data (obtaining a single, consistent model of the medium)
- justification, modeling and suppression of multiple waves for ground data (multiple waves from a free surface, intra-single waves)
- selection of absorption parameters, data processing without the use/after deducing deconvolution operators
- depth migration (Kirchhoff)
- iterative construction of DVM using reverse time migration algorithms (RTM)
- processing and migration of duplex waves
- processing and migration of multicomponent data
- 4D processing of marine seismic data
Processing of legacy seismic data
- compaction of source data
- special procedures for equalizing the noise component of data at different frequencies to calculate surface-consistent procedures
Processing of wide-azimuthal seismic data
- modeling and adaptive subtraction of surface waves based on dispersion spectra (fundamental, 1st and 2nd modes + scattered component)
- 3-dimensional modeling of linear interference waves in real coordinates with their subsequent adaptive subtraction in cross-spread sorting in real coordinates
- full 5D regularization of data to the original positions (Matching Pursuit Fourier Interpolation algorithm, resistant to aliasing at high frequencies)
- full 5D regularization of data on a compacted observation network with azimuth preservation
- construction of detailed velocity models involving well information, using grid and/or layer-by-layer tomography methods
- evaluation and selection of anisotropy parameters, coordination of anisotropy parameters with well data
Processing of marine seismic data
- suppression of multiple waves in the water layer
- suppression of multiple waves from a free surface
- suppression of linear interference in real coordinates
- suppression of repeated pulsations
- degosting PV, PP
Experience: 2008 to date
- Western Siberia – more than 5,000 sq. km and more than 10,000 sq. km
- Volga region – 5,000 sq. km, 1,500 km
- Eastern Siberia – 10,000 sq. km, 7,000 km
- Komi Republic – 3,000 sq. km., 500 km
- Arctic seas of Russia – 500 sq. km, 5,000 km
- Sakhalin – 2,000 sq. km
- Sierra Leone – 2,000 sq. km, 4,000 km
- Other regions, including Kamchatka, Belarus, Kazakhstan, Colombia, USA, Israel
Software: Promax and GeoDepth.
2. Petrophysical interpretation
At this stage, a database of well logs, well tests, core, descriptions of sludge, gas logging, and data from laboratory studies of reservoir fluids is being prepared. Primary data processing (linking, quality assessment etc. ) and the development of an algorithm for further work, depending on the requirements of the project and expediency are carried out.
Works may include:
- Petroelastic modeling (for both terrigenous and carbonate formations), preparation of materials for seismic inversion.
- Construction of petrophysical models for formations of various complexity, including carbonate and terrigenous formations, different types of porosity (matrix, cavernous, fractured), different types of saturation (oil/gas, layers with high water content), various diagenetic features (cavernosity, presence of bitumen in the pore space, presence of salts, carbonate cement). When constructing petrophysical models we use both deterministic and stochastic approaches. After the model is built, the point-by-point interpretation of well logs is performed directly
- Processing and interpretation of image logging data (electrical and acoustic imagers) to map cracks and identify fracture parameters. There is the possibility of a unique collaboration with a geomechanics and drilling specialist, which allows to consider the issue of fracturing from different sides.
- CTscan data processing with the application of approaches to automation of CTscan processing and the participation of this type of data in the allocation of reservoirs and porosity estimation.
- Typification of well sections by lithology, reservoir quality, facies features based on classical deterministic approaches, neural network methods, etc.
Experience: 2010 to date
- Western Siberia
- Eastern Siberia
- Sakhalin
- Kazakhstan
- Uzbekistan
- Pakistan
- Other regions
Software: Techlog, Interactive Petrophysics
3. Seismic and geological interpretation
The seismic interpretation implements the approach of complex analysis of well and geological data. All the experts in the group are not only geophysicists, but also have excellent knowledge of geology, sedimentology. This allows to carry out projects with a versatile view of the complex problems of geology. The list of works carried out is formed for specific project objectives with an emphasis on methods that are successful in specific conditions.
The work begins with a detailed analysis of the input seismic data – an assessment of the phase component of the sections, the noise level, the presence of multiple interference waves, processing artifacts. After that, the main interpretation strategy is worked out, which may include:
- Correlation of horizons. Automatic and volumetric correlation technologies in PaleoScan and Petrel can be used. These technologies make possible to avoid correlation of only the main horizons, and to create a detailed framework for subsequent amplitude analysis up to 150 horizons over a 2-week period.
- Construction of a fault model using Petrel, PaleoScan, Fault Likelyhood (DSG), Opendtect algorithms. Volumetric approaches to correlation and a set of seismic attributes (Discontinuity, AntTracking, Fault Likelyhood, etc.) are used. The presence of a geomechanic and a 3D modeling specialist in the team enables to perform QC and edit faults for further 3-dimensional modeling at the production stage.
- Construction of a velocity model, including Layer-cake models using velocity trends from velocity dive data and well data. Geosoftware and Petrel are used for high-speed modeling.
- Attribute analysis aimed at clarifying the facies model, quantitative assessment of reservoir properties (porosity, saturation type, thickness). Approaches include classical attribute analysis, spectral decomposition, AVO analysis using Pre-Stack data and AVO attributes, neural networks. The results are also used for volumetric allocation of GeoBody geological objects.
- Calculations of seismic inversions in HamsonRussell software for qualitative and quantitative assessment of reservoir properties. Detailed work is carried out together with petrophysicists to establish the prediction of properties, adjust probability density functions, and build compaction trends for terrigenous deposits. The seismic data is linked directly in the work, the parameters of the low-frequency model are adjusted, and the inversion algorithm is selected. It is possible to perform PostStack, PreStack deterministic and stochastic inversion. The QC process uses approaches developed on more than 15 projects.
- Integration of results and construction of conceptual and detailed three-dimensional geological models. This stage is the heart of the project and is provided through the joint creative efforts of specialists and detailed technical work. The concepts of formation of hydrocarbon traps, mapping of hydrocarbon traps, construction of structural models and models of reservoir properties are being built. All the other parameters of the petroleum system that affect the understanding of the risks of the subsequent study of these objects by drilling or seismic exploration are identified. For more reliable results, detailed work is supplemented with regional information from open sources (articles, publications, international databases). If the area of interest is at later stage of development, 3D geological models are built.
- Mapping of hydrocarbon traps, calculation of reserves according to international and Russian standards, estimation of uncertainty. Mapping is carried out using approaches that have proven themselves in large international and Russian oil and gas companies. When assessing reserves, a multilateral analysis of calculation parameters is implemented to take into account their possible uncertainties. Reserves are calculated using the Monte Carlo method in specialized software, as a result, the customer receives a set of possible scenarios for which the production profile and development scenarios can be calculated. The deliverables are accompanied by a geological risk assessment.
Experience from 2010 to the present:
- Western Siberia
- Eastern Siberia
- Sakhalin
- Kazakhstan
- Uzbekistan
- Pakistan
- Other regions
Software: Petrel, Desicion Space Desktop, PaleoScan, Qgis, Geosoftware, Rose & Associates.