Abstracts - Virtual Lecture Series 2016 - Season 1
The Power of Seismic Interpretation in Depth: Time-to-Depth and Re-Depth Solutions
One of the major challenges in seismic interpretation is seismic-to-well tie in the depth domain. When seismic is processed through isotropic velocity modeling and migration, more often than not, we observe that seismic depth deviates from the well depth of the same geological formation.
The criteria of seismic velocity modeling are to match seismic data to well data, to maintain the seismic velocity spatial variation and to avoid any artifacts, such as bull’s eyes.
Paradigm well data constrained time-preserving tomography provides solutions. This presentation illustrates technologies, workflows and examples of grid-based and model-based tomography. With these technologies, accurate seismic time-to-depth conversion or re-depthing can be achieved efficiently by seismic interpreters.
Featured Technologies: SeisEarth®, Explorer™ - Synthetics, T-D, D-D in Anisotropic Regimes - Mistie Tomography
Breakthroughs in Velocity Model Updates with Tomography (21:32)
From the outset, the velocity model building process is mathematically ill-posed, since one is solving for more unknowns vs. knowns (velocity, depth, anisotropic parameters), resulting in multiple models that can fit the data.
This presentation shows how Paradigm tackles the model non-uniqueness issue by incorporating well data, full azimuth data and geological constraints into the model building process. It includes a short overview of Paradigm's Tomography workflows and offers examples of how use these three data types in the process.
Featured technologies: GeoDepth® -SKUA®
Thin Bed Characterization with Seismic Attributes and Wedge Modeling (12:14)
The analysis of thin beds has always been challenging for interpreters. Even though we observe and agree on the high impact of thin layers in reservoir behavior, there are few methods to assess their presence directly from seismic data.
Seismic attributes, such as thin bed indicator, spectral enhancement or decompositions, cosine of instantaneous phase combined with others may provide some information, and improve the seismic image for thin bed analysis. However, any thin bed hypothesis should be modeled in order to understand the expected seismic response in case of thin bed presence. On the other hand, what could create a false positive?
Paradigm 15.5 introduces its new integrated wedge modeling tool. Interactive model generation allows the user to play the “what if” scenario, by combining thinning and fluid effects.
Featured Technologies: Stratimagic®, SeisEarth®, Epos® Wedge Modeling
A Robust Broadband Deghosting Procedure for High Resolution Outcomes (19:37)
Whenever a source and receiver are positioned below a strong velocity contrast, ghost reflections are generated. This is manifested as notches in the frequency domain and loss of low frequencies.
The reflection ghost problem has been known since the early days of marine acquisition. In spite of many advances in technology and acquisition configurations aimed at improving the frequency spectrum which deteriorates due to the presence of ghost reflections, the low resolution component of the spectrum is still missing. In recent years this topic has become of major interest due to FWI, where recovering low frequencies is crucial.
In this lecture we will present our Deghosting solution, we will explain the methodology, and compare the results to different acquisition techniques.
Featured Technologies: Echos® GhostX
Interpretation Validation (28:49)
Better acquisition techniques and improved seismic processing algorithms have led to significantly higher seismic image quality, with a corresponding increased amount of stratigraphic details. This creates a challenge for geoscientists who need to interpret more detailed seismic features from greater quantities of seismic data while facing the same deadlines. One of the ways in which interpreters alleviate this problem is by using mostly automated tracking tools.
However, in a complex structural and stratigraphic environment, geoscientists must spend a lot of time trying to propagate and correlate seismic reflectors. This usually results in obtaining a seismic interpretation that tends to be associated with clear impedance contrasts and some partially interpreted seismic events that are not of sufficient quality to be considered. This is especially critical in areas where the seismic data is noisy, the structure complex, or in specific geologic environments such as subsalt or unconventional plays, where rock types are very heterogeneous and seismic is characterized by low impedance contrasts. In these cases, the seismic stratigraphic information will be lost between the seismic interpretation and geologic modeling stages; and what is more likely, will lead to an inconsistent 3D geologic model. Seismic interpretation and modeling technologies need to honor the complex information embedded in the seismic data.
This presentation will consider an answer to this issue, which requires a multi-domain approach (G&G interpretation and modeling) and the integration of advanced technologies associated with each domain, as past modeling limitations (horizon and pillar-based technologies) made maintaining synchronization between the model and the current interpretation difficult.
Featured Technology: Stratimagic®
Comprehensive Seismic Data Analysis and Interpretation with Prestack Data (29:01)
Prestack seismic data is applied routinely in the process of Quantitative Seismic Interpretation (QSI) to generate varieties of seismic attributes, in order to estimate reservoir properties such as lithology, porosity and fluid. The quality of prestack seismic data governs the accuracy and uncertainties of rock property prediction.
The Paradigm QSI solution provides an integrated data repository for prestack/poststack seismic data, well data, and interpretation data. In this presentation, you will see a QSI workflow that includes:
Featured Technology: SeisEarth®, Epos® QSI
Resolving Data Integration and Modeling Challenges in the Unconventionals (18:09)
- Prestack data evaluation with visualization, interpretation and analysis
- Prestack preconditioning for seismic inversion
- Prestack inversion and interpretation to identify potential reservoirs
- Integrated analysis of various seismic attributes, such as Poisson’s ratio, Coherence Cube and spectral decomposition, to further understand the reservoir
From exploration to development, the key to success in unconventional reservoirs goes hand in hand with an operator’s ability to analyze and dynamically integrate the multi-disciplinary data collected into an integrated earth model.
This session will demonstrate a case study where interpretation of microseismic data was used to validate geomechanical properties extracted from seismic data. It will highlight the integration of multi-disciplinary data to reduce uncertainty by using microseismic events and their relative chronological occurrence as a proxy for fracture propagation, ”connecting the dots”, and validation of the elastic properties derived from a prestack seismic data inversion with the fracture propagation model from microseismic data.
This presentation will feature Paradigm’s SKUA-GOCAD modeling platform.
Featured Technology: SKUA-GOCAD™ Unconventionals
From Prestack to Rock type: A Neural Network Facies Inversion (16:21)
One of the big challenges for hydrocarbon recovery is combining geological information about lithology and geophysical data acquired through reflection seismic. As these data can take different forms (litho-logs, cuttings, and for seismic, post and prestack attributes) and can have different resolutions, the manual integration of all the information contained in them requires long analysis and is sometimes impossible to solve.
We therefore propose a new methodology for predicting lithology interpreted at wells using 3D seismic attributes (post and prestack). This technique aims at finding patterns in seismic attributes that will predict lithology kind, distribution and uncertainty, using a probabilistic approach.
This demonstration illustrates the principles of the methodology, and shows the workflow-based approach embedded in SeisEarth to successfully estimate rock type distributions from prestack data.
Featured Technology: Stratimagic® Democratic Neural Network
The Impact of Full-Azimuth Imaging on Resolving Subsurface Geology: Diffraction Imaging, Specular Imaging, Multiple Suppression (19:53)
E&P companies make huge investments in acquiring rich seismic data with wide azimuth and long offset, in an effort to obtain a more accurate definition of the reservoir, especially in fractured and sub-salt reservoirs. However, standard seismic imaging procedures that integrate or sum (stacking) seismic amplitude data for a large number of seismic events from energy arriving at different angles and all possible dips at each image point, result in smearing of the image along key subsurface objects. This is especially true in complex geological areas characterized by faults, pinchouts and material discontinuities. Consequently, standard discontinuity attributes (e.g. coherence, curvature, fault likelihood) can suffer from inaccuracy, instability, and considerable uncertainty when applied to poststack image volumes.
In this lecture we will discuss the benefits of a full-azimuth angle domain imaging system. The key advantage of this system is its ability to decompose and separate the wavefield into reflection and diffraction energy. Specular reflection stacks can be used to emphasize and interpret major continuous events and major discontinuities. On the other hand, diffraction stacks can be used to interpret and delineate high-resolution subsurface stratigraphic and structural features, such as small scale faults, tips and fractures. (Diffraction energy is often masked by reflection energy in conventional processing and methodologies.) This technology can be used to complement standard poststack oriented interpretation.
Featured technologies: EarthStudy 360®
Efficiencies in Large Volume Interpretation: Compression Roaming and Dependencies (22:49)
In the O&G industry, seismic data is the largest consumer of data storage, accounting for up to 90% of enterprise storage requirements. Size and complexity are growing exponentially and posing a variety of challenges to the industry. With the introduction of rich, wide and full-azimuth seismic data acquisition, and the development of advanced processing, imaging and interpreting technologies, datasets are exceeding 40-50 TB.
Until today, the industry’s solution has been to provide geoscientists with ongoing hardware upgrades, in order to support data and projects, or even maintain access to the original SEG-Y files from the selected petro-technical solution, in order to avoid duplication. IT departments need to find better solutions and are now facing a strategic choice between maintaining “instantaneous need-dependent” growing hardware, or seeking out a different approach that will benefit both their geoscientists’ requirements and their long-term operations.
But what if seismic data size can be controlled and reduced without losing any of the geoscientists’ valuable information?
Paradigm, in collaboration with Hue, has implemented a proven, high-performance seismic compression algorithm in its poststack interpretation solution. Our customers now have the option to compress their seismic data, saving disk space while retaining 32-bit precision. Efficient seismic data access-transfer and decompression are achieved through optimal use of the workstation’s graphical and CPU capabilities, to parallelize the decompression of seismic volumes from the application itself.
This presentation will show how the seismic compression roaming technology is implemented in our G&G Interpretation solution, and reveal the significant benefits of this strategy.
Featured technologies: SeisEarth®