The study entailed mapping of structural framework, horizon picking, wavelet extraction, log editing and correlation, building of lowfrequency model, acoustic impedance inversion and crossplot analysis of reservoir properties. While no direct relationships have been established between all of the attributes and the physical and geological characteristics of the earth, almost all of the articles describe various uses of seismic attributes as effective discriminators for the purpose of classification. Using the geodata investigator we can crossplot our angle stacks or intercept and gradient to get a quick look at any avo effect. Using 3d seismic attributes in reservoir characterization. Next we crossplot this curve with other attributes that can be computed from seismic data. Seismic inversion and well log data were integrated to image and characterize lithofacies at reservoir zones of interest. We would like to use the cross plot matrix option to find out which pair of attributes can best discriminate the gas sand. The geometrical attributes have the capacity to enhance the visi. The milton dobrin lecture april, 2010 brian russell hampsonrussell. In modern seismic data interpretation, amplitude variation with offset it is. Seismic modelling forms the basis for understanding the seismic signature.
Sequential geological modeling approach uses multiple seismic attributes as a. Using 3d seismic attributes in reservoir characterization 1. Seismic attribute analysis for reservoir characterization. Then, after 2d crossplot analysis in the rave module was performed. 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. The porosity log data gives the porosity at the well location to be 25% 35%. But no matter how new and sophisticated the algorithm, seismic pattern recognition rests on an old and simple foundation. Detecting stratigraphic features via crossplotting of seismic discontinuity attributes and their volume visualization interpreters corner coordinated by alan jackson satinder chopra, arcis corporation, calgary, canada kurt j. Hydrocarbon, reservoir, well logs, crossplotting, lithology.
It has been applied much more widely in recent years and is now an important tool for many geoscientists. Extended elastic impedance eei has proved to be a highly convenient framework for seismic avo studies. Formation evaluation of an unconventional shale reservoir. The third goal is to explore elastic anisotropy of nsa shale in both core plugs and logging measurements. The attribute measurements are utilized to characterize the subsurface structure and depositional system such as fluvial dominated channels. This capability is fully integrated with the kingdom platform to create a timeefficient.
Integrating surface seismic, microseismic, rock properties. A petrel plugin to draw three dimensional crossplots from well and seismic data. The most recent papers have concentrated on reservoir characterization. You need to check on the toggle s in order to apply the filters. Seismic attributes fall into two broad categories those that help us quantify the morphological component. The figures show the a crossplot between near and far ei logs, and b the zones on the logs. The scales are usually linear but may be other functions, such as logarithmic. Seismic attributes a promising aid for geologic prediction. Reconnaissance surveys of 2d seismic data are acquired before most 3d seismic surveys to define the area of interest and regional trends. The directness of the eei method is one of its strengths, making.
The complex seismic trace attributes are found in some instances to correlate with lithological changes and historically have been used to characterize hydrocarbon reservoirs. Avo analysis introduction avo preprocessing avo modeling avo parameters avo crossplot analysis avo attributes some application of avo probabilistic avo analysis. 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. Animation of the seismic inlines in the direction of the white arrow helps figure 1. There are two key elements of the seismic wavelets.
A suite of properties of seismic trace such as amplitude, phase, and frequency can be crossplotted with the well logs to find the relation between. When we crossplot v p v s ratio against pimpedance, the zone of low values of each. Reliable estimation of petrophysical parameters is needed as input for such studies. By estimating avo attributes from prestack seismic data it is possible to extract important information about hydrocarbons.
The efficiency of seismic attributes to differentiate. Unlike commonly used approaches to map facies or lithologies from seismic data based on selecting regions in seismic attribute crossplots. Wellington field 3d seismic volume using the avo interceptgradient crossplotting technique. Programs hlplot, hsplot, hlsplot, rgbplot and crossplot attributeassisted seismic processing and interpretation page 4 the first image is a 2d color bar. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to.
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. Bandwidth is a range of frequencies above a given amplitude threshold. The seismic section top left hides prestack information. Avo intercept and gradient attributes were extracted from the linear regression of prestack seismic data.
Integrating seismic acoustic impedance inversion and. While seismic attributes are routinely applied to 3d data, they are less commonly applied to 2d data. Detecting stratigraphic features via crossplotting of. Switch to the filters tab in the viewer options window, then choose add filter. The software supports crossplotting on different types of data, such as seismicdriven data volumes, horizons and interpretation data, well data, synthetic data wells and vertical functions. Cross plot seismic attributes in this example, we are going to create multiple seismic cross plots using p impedance, vpvs ratio, and s impedance. Marfurt, the university of oklahoma pc, including laptops. Subsequently, the elastic approach is discussed and finally the benefits of seismic modelling with advantages of multidisciplinary reservoir studies are demonstrated. A typical crossplots that shall be done in this work is the crossplot of v p v s ratio against acoustic impedance zp. Seismic attributes and their applications in seismic. Building more robust lowfrequency models for seismic. The derivation of net pay estimates from seismic attributes is a technology that has been around for quite a while brown et al, 1984. Pdf seismic attributes and avo analysis by ahmed hafez.
Of course, if there is variation in the fundamental nat ure of. Notice the decrease in the elastic impedance value on the far angle stack. By combining attribute analysis, avo attribute analysis, prin and supervised facies cipal component analysis. Crossplots of porosity and a instantaneous amplitude b quality factor. A judicious choice of opacity applied to edgesensitive attribute subvolumes, such as curvature or coherence, corendered with the seismic amplitude volume can. Pdf on apr 1, 2007, flaviana almeida costa and others published using. This study used poisson impedance attributes and crossplots from prestack seismic inversion and well logs to discriminate and predict hydrocarbonfilled reservoirs in the bumma field, greater ughelli depobelt, niger delta basin. Seismic attribute crossplots for example a plot of seismic amplitude, instantaneous phase and instantaneous frequency gives much information about reservoir properties. Analyses of relevant seismic attributes such as rootmeansquare rms amplitude, maximum amplitude, average energy amplitude, average magnitude amplitude, maximum magnitude attribute, and standard deviation amplitude, which were applied on reservoir tops, revealed sections with bright spot anomalies. A supervised modelbased simultaneous inversion of poisson impedance pi and crossplot was carried out on the prestack seismic data to understand the lithofacies classification and fluid types.
Perform seismic inversion study and obtain porosity, toc, and resistivity volumes within the austin chalk and the eagle ford shale that could be used to augment hydrocarbon exploration efforts. It helps in the prediction of reservoir characteristics away from well control points. Their great number and variety is almost overwhelming. Pdf on jan 19, 2018, ahmed hafez and others published seismic attributes and avo analysis by ahmed hafez find, read and cite all the research you need on researchgate. The porosity log data derived from the well log with different seismic attributes. Debanjan datta, suman mehta and sanchit agarwal, indian school of mines summary we present a unique plugin in petrel capable of visualizing 3 well or seismic attributes in three dimensions. Reservoir characterization using seismic reflectivity and attributes.
Pdf using seismic attributes in petrophysical reservoir. Integrating all of the attributes in a single 3d view significantly strengthens the summation of the outputs and enhances seismic interpretation. In this example, area and twt are used to filter the data. The avo analysis seeks to extract this hidden information about rock and fluid properties. Simultaneous avo inversion of prestack data showed better. The rapid progress in seismic attributes started after the using of 3d seismic data and the colored seismic profiles barnes, 2001, chopra and marfurt, 2005. Amplitudeversusoffset avo principles the amplitude character of seismic reflections varies with offset, due to changes in the angle of incidence. That attribute pair which shows the best correlation is picked up and the relationship between them is deter mined. Fracturing changes the rock properties and therefore the attributes of the seismic data.
New technologyseismicseismic interpretation august 9, 2007 hays, ks. Th en, using opacity control features, we retain only the high values displayed in red resulting in the fault skeleton which we corender with the seismic volume for visual correlation. 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. 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. It also has the capability to plot three seismic attributes in three dimensions. Cross plotting of rock properties for fluid and lithology. A twodimensional plot with one variable scaled in the vertical y direction and the other in the horizontal x axis. The plot also highlights the difficulties in differentiating fluid and lithology at low porosities attributes. Obtain pertinent seismic attributes that could be used to characterize the.
Extended elastic impedance and the avo crossplot whitcombe et al. The pdf s which are applied to inverted seismic volumes honour the distribution of well log data in the lmr crossplot space figure 4. Seismic attributes provide the seismic interpreter with new images that can enhance both the physical and geometric descriptions of the subsurface. Throw away all the unnecessary attributes and what is left over is quite manageable. 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. On the right of the 2d color bar is the 1d color bar that you will load into your interpretation workstation. The porosity is estimated from the crossplot analysis between instantaneous amplitude attribute and the porosity log derived from the well location. The black lineaments align with the faults that one can see on the amplitude strat slice. The crossplot plug in is not only limited to well parameters. Porosities plot successively down the crossplot showing the dependency of acoustic impedance on porosity. Find and apply the type of filters you like to use in the drop down list.
Application of crossplot and prestack seismicbased. Using seismic attributes in petrophysical reservoir characterization. The integrated use of spectral decomposition, avo analysis. Conventional poststack seismic attributes cannot predict the reservoir effectively, while prestack seismic inversion also has difficulties in application for the low snr seismic data. Detecting stratigraphic features via crossplotting of seismic. Using 3d seismic attributes in reservoir characterization susan nissen geophysical consultant mclouth, ks kansas next step 2007 seminar. Poststacked 3d seismic data, composite well logs, and velocity checkshot data were used for the reservoir analysis. Lithology, rock properties were determined from the interceptgradient crossplot. Eei logs can be directly related to the petrophysical properties of interest and seismic eei reflectivity volumes can be obtained directly from the prestack data via linear projection in sin2t. Seismic pattern recognition has been developing quietly but steadily for twenty years, and the first practical applications are now appearing. Seismic attributes are the components of the seismic data which are obtained by measurement, computation, and other methods from the seismic data. Seismic attributes reveal information, which are not readily apparent in the raw seismic data. This provides a preliminary insight into possible sources of shale anisotropy in nsa, thus enhancing the prospect of applying seismic anisotropy attributes amplitudeversus. In elastic impedance inversion the seismic, model and output are as shown here.
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