Since the mid1970s seismic attributes have been used as hydrocarbon indicators. Seismic facies waveform analysis mainly extracts seismic trace waveforms within a certain time window from 3d seismic data and divides the seismic trace waveform using neural networks. Physically, both of them are capable of measuring the most and least. Multiwaveform classification for seismic facies analysis. Jul 06, 2014 seismic attributes were introduced as a part of the seismic interpretation in early 1970s any information of interest that can be derived from seismic is seismic attributes 3. The advanced seismic attributes analysis a seismic attribute is any measure of seismic data that helps us better visualize or quantify features of interpretation interest.
Application of seismic attribute analysis in fluvial seismic. Emerging and future trends in seismic attributes, published in seg the leading edge. Seismic attributes for reservoir studies petrowiki. The fullwaveform synthetic waveforms are used to evaluate timelapse seismic attributes resolution for more realistic synthetics. The synthetic waveform data are processed using timelapse seismic techniques for both prestack and post. The may issue of interpretation features two special sections on seismic geometric attributes and interpretable seismic velocity. Given the previous background, kohonen 2001 defines the som.
Application of seismic attributes for delineation of. Seismic attributes analysis for reservoir characterization. These could be based on analysis of either the seismic waveforms or the seismic attributes. Facies classification based on seismic waveform a case. Different approaches can be used to search and identify these from the seismic data. Seismic attributes are the components of the seismic data, which are obtained by measurement, computation, and other methods from the seismic data. Seismic attribute analysis can extract information from seismic data that is, otherwise, hidden in the data and have been used to identify prospects, ascertain depositional environments. Seismic interpretation an overview sciencedirect topics. Attributes for fluvial channel interpretation seg wiki. Key to the analysis is discovering the linear, and often nonlinear, relationships between the seismic trace and. Seismic facies identification and classification using. The stacked seismic data volume is commonly used for interpretation of geologic structure and seismic attributes. For indepth analysis of waveform, instantaneous phase, amplitude and frequency component can be extracted.
Any variations observed in these parameters are again interpretable results of. Subscribe recommend to a librarian submit an article front matter. Elastic properties and their spatial arrangement geometric distribution must be considered. Coherence is a continuity attribute that detects edges or discontinuities in seismic data along a horizon or time slice. Most of the attributes, instantaneous or wavelet, are a function of the characteristics of the reflected seismic wavelet. Quantitative interpretation of seismic facies a case. Attributes are typically derived from normalincidence seismic data on a tracebytrace basis and are presented in a. The meaning and use of some attributes can be quite straightforward. More research work in this direction may lead to innovative and useful ways of assessing the hydraulic properties of fractured rockmass remotely from seismic information. Modern techniques using waveform classification make it possible to define and map subtle changes in seismic response and to match them to subsurface information. Reflector dip estimates based on seismic waveform curvatureflexure analysis. Facies classification based on seismic waveform a case study. In our experience, neural network based waveform classification has proven to be a successful tool to identify these zones.
Wheeler transformation methods and seismic attribute analysis, particularly focusing on minimum. Seismic attributes typically provide information relating to the amplitude, shape, and position of seismic waveform. Pdf seismic sequence analysis and attribute extraction. These are routinely used to enhance both the physical and. Characterization of fractured zones via topological analysis of 3d seismic diffraction images. Seismic images alone do not contain enough information to reveal these regions, so seismic attributes are used to aid analysis. Facies constrained classification is a twostage process. Attribute analysis of 3d seismic data in time slices presents a great. In reflection seismology, a seismic attribute is a quantity extracted or derived from seismic data that can be analyzed in order to enhance. Combining information from adjacent seismic samples and traces using a physical model such as dip and azimuth, waveform similarity, or frequency content, seismic attributes often organize features into displays that.
Using 3d seismic attributes in reservoir characterization. Multivariate analysis of attributes is heuristically. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to. In this study, we present a case study, where instantaneous frequency variation in response to a thin hydrocarbon pay zone is analyzed and integrated with other independent information to explain. Classification of seismic attributes the seismic attributes are classified basically into 2 categories. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Fluvial channels and systems are just one type of landform and process involved in the broader topic of geomorphology. Waveforms from fractured zones were obtained by a superposition of reflections from horizontal fractures with a varying distribution of fracture length, aperture and spacing. Complex trace and seismic trace analysis attribute. Quantitative interpretation of seismic facies a case study. Seismic attributes reveal information, which are not readily apparent in the raw seismic data. Seismic facies classification techniques have been used for years in interpretation and reservoir characterization workflows. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in. Calculate vpvs, poisson ratio and elastic parameters.
Multi attribute analysis an effective visualization. For certain geological provinces these indicators have given encouraging results. It is this organization of redundant information contained within multiple seismic attributes that allows principal component analysis to excel at waveform classification in areas where well control is limited for a constrained result. Seismic attributes typically provide information relating to the amplitude, shape, andor position of the seismic waveform.
Use of seismic attributes in reservoir characterization. Formation selforganizing maps for seismic facies analysis. Application of seismic facies classification, spectral. Most of these attributes are of commercial interest and, use of many of the. Seismic attributes and their applications in seismic.
Understanding the seismic disorder attribute and its applications, published in segthe leading edge. Signal adaptive quadratic timefrequency representations have considerably better timefrequency localization properties resolution than more standard approaches. Characterizing geological facies using seismic waveform. Since their introduction in the early 1970s, complex seismic trace attributes have gained considerable popularity, first as a convenient display form, and later, as they were incorporated with other seismicallyderived measurements, they became a valid analytical tool for lithology prediction and reservoir characterization. Stewart abstract attribute analysis of 3d seismic data in time slices presents a great opportunity for reservoir characterization. Timelapse seismic waveform modelling and attribute. Application of seismic attributes for delineation of channel. This is concerned with study of wave shape, polarity, continuity, dip, frequency, phase, and amplitude. The variation of frequency content with time is an important seismostratigraphic indicator. Seismic attributes were introduced as a part of the seismic interpretation in early 1970s any information of interest that can be derived from seismic is seismic attributes 3. The interpretable information of the 3d seismic data can be enhanceded with complex seismic trace attributes. Signal adaptive quadratic timefrequency representations have considerably better timefrequency localization properties resolution than more. Pdf reflector dip estimates based on seismic waveform. Reflector dip estimates based on seismic waveform curvature.
It is computed by measuring the similarity of seismic waveforms in different directions. This paper discusses the analysis of local frequency content of seismic reeection data with quadratic joint timefrequency representations. Seismic waveform shape and character can define facies and reservoir parameters with far greater detail than traditional time and amplitude mapping. Pdf seismic attributes and avo analysis by ahmed hafez. Spectral decomposition analysis, avo analysis, multiple attributes analysis, principal component analysis, supervised neural facies classification, and waveform calibration successfully delineate reservoirs with hydrocarbon potential. However, we demonstrate in this paper that the quantitative interpretation of seismic facies is possible provided a geological. Seismic attributes were introduced as a part of the seismic interpretation in early 1970s. A seismic facies is the manifestation of the underlying geologic facies or structural feature in the seismicamplitude data. Traditional method is using the single waveform to classify the seismic facies. The most common attribute is simply amplitude, although its interpretation in thinlayered beds is not necessarily straightforward. Seismic attributes in geological interpretation aapg wiki.
Seismic attributes fall into two broad categories those that help us quantify the morphological component of seismic data and those that help us. In reflection seismology, a seismic attribute is a quantity extracted or derived from seismic data that can be analysed in order to enhance information that might be more subtle in a traditional seismic image, leading to a better geological or geophysical interpretation of the data. Seismic facies identification and classification using simple. Acknowledgements the authors would like to thank orleans energy ltd. This module is to detect the first arrival and pick the onset time automatically. Extracting meaningful information from seismic attributes, published in canadian discovery journal. Second, the complex seismic trace is incorporated into our workflow of waveform curvatureflexure analysis to enhance the accuracy of dip estimation in the presence of seismic noises, especially. By the advancement in the seismic attributes, spectral decomposition has also highlighted channels 4 5. Oct, 2015 the model is first applied to a set of well logs at a colocated site, nghp0110, following which the application is extended into the seismic domain by 1 the incoherency attribute as a proxy for secondary porosity and 2 a fullwaveform inversionbased pwave velocity.
The characteristic waveform parameters were estimated from a multifractal analysis of 1d synthetic seismograms generated using a variation of the reflectivity method. Here, the wavelets must be understood in the sense of the constant shape wavelets used in wavelet analysis e. Preconditioning of seismic data with 5d interpolation for computing geometric attributes. Seismic attributes reveal features, relationships, and patterns in the seismic data that otherwise might not be noticed. Seismic characterization of submarine gashydrate deposits in the western black sea by acoustic fullwaveform inversion of oceanbottom seismic data. Seismic waveform simulation using hydromechanical reservoir. Figure 38 initial spectral decomposition using the wavelet transform of seismic signal from. The fullwaveform reflection seismic data are used to study the influence of overburden effective stress changes that induce lateral and vertical velocity changes in order to investigate the uncertainties in timelapse seismic attributes. The goal of seismic attribute analysis is to improve the spatial prediction of structural and stratigraphic features, as well as petrophysical and geomechanical rock properties throughout the reservoir. Specific 3d seismic attributes can better help image fluvial channels in the subsurface and aid in the characterization of fluvial processes and further depositional analyses. Amplitude is often found to correlate strongly with porosity andor liquid saturation oilwater vs. From the time of their introduction in early 1970s seismic attributes gone a long way and they became a aid for geoscientists for reservoir characterization and also as a tool for quality control. The full waveform synthetic waveforms are used to evaluate timelapse seismic attributes resolution for more realistic synthetics.
Qualitative analysis of seismic facies derived from the classification is a common practice. Low coherency is delineated by seismic character discontinuity across boundaries. The timelapse seismic traveltime shifts and time strains from prestack and poststack data calculated from the synthetic seismograms are in a reasonable agreement with the respective input elasticity model. Second, the complex seismic trace is incorporated into our workflow of waveform curvatureflexure analysis to enhance the accuracy of dip estimation in the presence of seismic noises, especially in the zones of weak reflection intensity, such as zero crossings.
Spectral decomposition analysis is a significantly vigorous method in seismic data processing and interpretation. Seismic waveform shape and character define facies with significant detail compared to time and amplitude mapping. Channels will exhibit this low coherency across the seismic trace as seen. Horizon attributes measures of the data that occur along a 3d surface through the seismic volume volume attributes measures of the data that occur over an interval of time through the seismic volume attribute meanings. Causes and appearance of noise in seismic data volumes, published in aapg explorer 20. Seismic attribute analysis for reservoir characterization mohammad anees summary seismic attributes can be important qualitative and quantitative predictors of reservoir properties and geometries when correctly used in reservoir characterization studies. The integrated use of spectral decomposition, avo analysis. Any measurement derived from the seismic data is a seismic attribute. This can help guide the initial selection of attributes and will certainly help with interpreting the resulting data. Consider the geological feature you are hoping to interpret and how varying that aspect of the geology might affect the seismic data.
Seismic attributes can be conveniently defined as the quantities that are measured, computed or implied from the seismic data. Seismic attribute analysis for reservoir characterization. However, velocity and absorption are measured as quantities occurring between two interfaces, or within a bed. Use of multifractal seismic waveform parameters to. In addition, we use the actual drilling information as a model to conduct a series of correlation analyses and iterative calculations. That is, we consider the interfaces between two beds. Seismic facies analysis provides an effective way to delineate the heterogeneity and compartments within a reservoir. Seismic attributes are the components of the seismic data which are obtained by measurement, computation, and other methods from the seismic data. Seismic waveform carries information about frequency, phase and amplitude. Seismic attribute analysis can extract information from seismic data that is otherwise hidden in the data and have been used to identify prospects, ascertain depositional environments e. Seismic attributes were introduced as a part of the seismic interpretation in early.
Facies classification based on seismic waveform below zone of interest. It is advisable to have more than one window as per objective. Seismic facies classification is based on shape and character of the seismic waveform, which is often used for identifying facies distribution. Seismic attribute analysis provides information related to structure, stratigraphy, and reservoir properties. Since then many new attributes were derived and computed. A seismic facies can be defined as a group of seismic amplitude variations with characteristics that differ distinctly from those from other facies.
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