In the earth, seismic waves can propagate as longitudinal p or as shear s waves. Seismic attributes were introduced as a part of the seismic interpretation in early 1970s. This is concerned with study of wave shape, polarity, continuity, dip, frequency, phase, and amplitude. Developing a seismic pattern interpretation network arxiv. Throw away all the unnecessary attributes and what is left over is quite manageable. Seismic attributes provide the seismic interpreter with new images that can enhance both the physical and geometric descriptions of the subsurface. Seismic attributes should not vary greatly in response to small changes in the data. Todays low commodity prices call for the utilization of all available data.
Schlumberger oilfield dictionary seismic attributes reveal features, relationships, and patterns in the seismic data that otherwise might not be noticed. Petrophysical and seismic attribute analysis to decipher the. Jul 16, 2017 this is part 1 of a tutorial describing the method of generating seismic attributes in petrel 2015. Dipmagnitude and dipazimuth rijks and jaufred 1991 showed that horizonbased. For users of the vanguard seismic inversion and property generation system, seismic attributes can be used to predict desired log curves through a neural network. Frequency decomposition of seismic data by gaynor paton. Since then many new attributes were derived and computed. Seismic attributes are the components of the seismic data which are obtained by measurement, computation, and other methods from the seismic data. Geometric attributes help define the structural and stratigraphic framework of the seismic interpretation, while physical attributes may be useful as direct hydrocarbon or lithologic indicators. Depends on changes in velocity, density, and poissons ratio i.
Since then there has been an explosion in the number of attributes that can be generated and displayed in 3d interpretation systems. Coherence is one of several seismic attributes which is a measure of similarity between waveforms or traces in 2d or 3d seismic volumes. Dipmagnitude and dipazimuth rijks and jaufred 1991 showed that horizonbased dipmagnitude and dipazimuth are useful in delineating subtle faults whose displacements measure only a fraction of a seismic wavelet. In some cases, depending on one seismic attribute does not produce accurate. The complex seismic trace attributes are found in some instances to correlate with lithological changes and historically have been used to characterize hydrocarbon reservoirs. For free space, the onedimensional wave equation is derived.
This is part 1 of a tutorial describing the method of generating seismic attributes in petrel 2015. Seismic pattern recognition has been developing quietly but steadily for twenty years, and the first practical applications are now appearing. Avo principles, processing and inversion crewes research report volume 18 2006 5 r. Understanding attributes and their use in the application of neural analysis.
Sheriff, 1977, application of amplitude, frequency, and other attributes to stratigraphic and. Emerging and future trends in seismic attributes mcee university. Selection of seismic attribute and their processing for analysis it is always a critical stage of research, because selection of seismic attributes is one of the main steps in recognizing stratigraphic events and to overcome pitfalls in interpretation. I define local attributes with the help of regularized inversion and demonstrate their usefulness for measuring local. 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. While seismic attributes are routinely applied to 3d data, they are less commonly applied to 2d data. Understanding attributes and their use in the application. Well data are gotten from rock samples and measurements at depth from a wellbore.
However, the most important implementation of seismic attributes is to acquire information from the raw seismic data which is not easily obvious anees, 20. Seismic attributes and their classification alistair r. Lesson 11 basics of seismic interpretation youtube. Horizon attributes were first used in the mid1980s for interpreting fault traces on reservoir horizons. A seismic interpretation study should access the following data sets 2d or 3d seismic data cube. Although the calculated frequency values at times t 1 and t 2 shown by the solidline curve are physically impossible because they are negative, these anomalous frequency behaviors are some of the most useful seismic attributes that an interpreter can use. Every point on the wave front is a source of a new wave that travels out of it in the form of spherical shells. Seismic coherency is a measure of lateral changes in the seismic response caused by variation in structure, stratigraphy, lithology, porosity, and the presence of hydrocarbons. Amplitude derived attributes are useful in providing structural and stratigraphic details by providing physical parameters about the subsurface like acoustic impedance, and other properties. Seismic attributes seismic interpretation often relies on attribute sections and 3d images. Bringing together advances in technical disciplines such as artificial intelligence, data.
Seismic attributes not all attributes are born equal. Seismic attributes and their applications in seismic. The primary objective of this course is to gain an intuitive understanding of the kinds of seismic features that can be identified by 3d seismic attributes, the sensitivity of seismic attributes to seismic. Using 3d seismic attributes in reservoir characterization. Sep 19, 2007 using 3d seismic attributes in reservoir characterization 1. Seismic attributes enhance subtle amplitude and phase variations in the seismic. Seismic attributes reveal information, which are not readily apparent in the raw seismic data. Local seismic attributes measure seismic signal characteristics not instantaneously, at each signal point, and not globally, across a data window, but locally in the neighborhood of each point. When applied to the schiehallion field data, an interpretation approach is used to interpret pressure and saturationanomalies in frequent timelapse seismic, using all available sources of data. Using 3d seismic attributes in reservoir characterization 1. Integrated seismic interpretation, 2d modeling along with. Seismic attributes represent subsets of the information in the seismic data. Seismic attributes and their classification the leading.
Seismic attribute analysis for reservoir characterization. Seismic interpretation an overview sciencedirect topics. Identification of channel geometries applying seismic. Application of seismic attributes for delineation of channel. Seismic attributes that highlight discontinuities in the seismic data are useful for fault and fracture characterization. Seismic facies identification and classification using. Quantities that are not subsets of the data are not attributes and should not be used as attributes. Stewart abstract attribute analysis of 3d seismic data in time slices presents. Seismic attributes for stratigraphic feature characterization. Seismic basics in 5 pages university of saskatchewan.
Most of these attributes are of commercial interest. Seismic attributes enhance subtle amplitude and phase variations in the seismic signal that are often quite difficult to see on the original data. He is an adjunct professor at clemson university and was formerly a research associate professor at the university of south carolina. Pdf quantitative use of seismic attributes for reservoir. The primary objective of this course is to gain an intuitive understanding of the kinds of seismic features that can be identified by 3d seismic attributes, the sensitivity of seismic attributes to seismic acquisition and processing, and how independent seismic attributes are coupled through geology. This attribute is designed to emphasize discontinuous events, like faults in structural interpretation. Attributes can be measured at one instant in time or over a time window, and may be measured on a single trace, or on a set of traces or on a surface interpreted from seismic data. Stewart abstract attribute analysis of 3d seismic data in time slices presents a great opportunity for. Subsurface structure analysis using computational interpretation. 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. Seismic attributes are the components of the seismic.
Lesson 11 basics of seismic interpretation iris earthquake science. The advancement in the ability to generate seismic attributes and the growing emphasis on production geophysics has led to the widespread use of seismic attributes as a predictors of reservoir. Basic principles of the seismic method in this chapter we introduce the basic notion of seismic waves. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to. Raypaths are lines that show the direction that the seismic wave is propagating. The third and final stage of the hierarchy of seismic interpretation is seismic attribute analysis taner and sheriff, 1977. In this course the students learn the theory and practical workflows needed for effectively using post stack seismic attributes in seismic interpretation. Attributes are measurements based on seismic data such as polarity, phase, frequency, or velocity. Attribute analysis of 3d seismic data in time slices presents a great opportunity for reservoir characterization. This presentation explores the many categories of seismic attributes created in the last 20 years and their general use in. Seismic attributes for prospect identification and reservoir characterization.
New technology seismic seismic interpretation august 9, 2007 hays, ks. While seismic attributes are routinely applied to 3d data, they are. Attributes that differ only in resolution are the same attribute. But no matter how new and sophisticated the algorithm, seismic pattern recognition rests on an old and simple foundation. The course content covers the most common seismic attributes, discusses the theory, attribute management and visualization. Seismic rays are used instead of the wave front to describe the wave propagation. Attributes are secondary properties derived from prestack reflection data or more often from the images. Seismic facies identification and classification using simple. But no matter how new and sophisticated the algorithm. The geometrical attributes have the capacity to enhance the visi. Unlike shaded relief maps that allow 3d visualization of faults and channels from horizon picks, seismic coherency operates on the seismic data itself and is therefore. See mathematical details in the seismic basics in 5 pages on page 5.
For users of the vanguard seismic inversion and property generation system, seismic attributes can be used to predict desired log curves through a neural network inversion. Their great number and variety is almost overwhelming. He has extensive experience in subsurface mapping, seismic. Seismic attribute analysis for reservoir characterization mohammad anees summary seismic attributes can be important qualitative and quantitative predictors of reservoir properties and. The variation in the amplitude of a seismic reflection with angle of incidence or sourcegeophone distance. Reconnaissance surveys of 2d seismic data are acquired before most 3d seismic surveys to define the area of interest and regional trends. Seismic attributes extract information from seismic reflec tion data that can be. Application of seismic attributes for delineation of. Aug 03, 2017 lesson 11 basics of seismic interpretation iris earthquake science.
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. Accordingly, two types of attributes were introduced, the seismic connectivity attribute sca and the laplacian attribute. 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. Comparison of post stack seismic inversion methods. The milton dobrin lecture april, 2010 brian russell hampsonrussell, a cggveritas company. Seismic interpretation training course petroskills si1. Avo analysis examines the basics of amplitude varia tions with. Often a client desires to use seismic attributes in a reservoir characterization.
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