We would like to use the cross plot matrix option to find out which pair of attributes can best discriminate the gas sand. Animation of the seismic inlines in the direction of the white arrow helps figure 1. Programs hlplot, hsplot, hlsplot, rgbplot and crossplot attributeassisted seismic processing and interpretation page 4 the first image is a 2d color bar. Crossplots of porosity and a instantaneous amplitude b quality factor. Cross plot seismic attributes in this example, we are going to create multiple seismic cross plots using p impedance, vpvs ratio, and s impedance. Seismic attributes a promising aid for geologic prediction. The scales are usually linear but may be other functions, such as logarithmic. 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. 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.
There are two key elements of the seismic wavelets. The third goal is to explore elastic anisotropy of nsa shale in both core plugs and logging measurements. The avo analysis seeks to extract this hidden information about rock and fluid properties. Avo intercept and gradient attributes were extracted from the linear regression of prestack seismic data. Unlike commonly used approaches to map facies or lithologies from seismic data based on selecting regions in seismic attribute crossplots. The geometrical attributes have the capacity to enhance the visi. 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. By combining attribute analysis, avo attribute analysis, prin and supervised facies cipal component analysis. 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.
Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to. Then, after 2d crossplot analysis in the rave module was performed. Using seismic attributes in petrophysical reservoir characterization. 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. While seismic attributes are routinely applied to 3d data, they are less commonly applied to 2d data. The crossplot plug in is not only limited to well parameters. 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. Their great number and variety is almost overwhelming.
Seismic modelling forms the basis for understanding the seismic signature. Using 3d seismic attributes in reservoir characterization. The plot also highlights the difficulties in differentiating fluid and lithology at low porosities attributes. By estimating avo attributes from prestack seismic data it is possible to extract important information about hydrocarbons. 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. Fracturing changes the rock properties and therefore the attributes of the seismic data. The porosity log data derived from the well log with different seismic attributes. Cross plotting of rock properties for fluid and lithology. The milton dobrin lecture april, 2010 brian russell hampsonrussell. It also has the capability to plot three seismic attributes in three dimensions. The integrated use of spectral decomposition, avo analysis. Seismic attributes and their applications in seismic. Detecting stratigraphic features via crossplotting of seismic.
Marfurt, the university of oklahoma pc, including laptops. Switch to the filters tab in the viewer options window, then choose add filter. That attribute pair which shows the best correlation is picked up and the relationship between them is deter mined. 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.
Building more robust lowfrequency models for seismic. The black lineaments align with the faults that one can see on the amplitude strat slice. Subsequently, the elastic approach is discussed and finally the benefits of seismic modelling with advantages of multidisciplinary reservoir studies are demonstrated. You need to check on the toggle s in order to apply the filters. Pdf on apr 1, 2007, flaviana almeida costa and others published using. A typical crossplots that shall be done in this work is the crossplot of v p v s ratio against acoustic impedance zp. Seismic inversion and well log data were integrated to image and characterize lithofacies at reservoir zones of interest. Conventional poststack seismic attributes cannot predict the reservoir effectively, while prestack seismic inversion also has difficulties in application for the low snr seismic data. Next we crossplot this curve with other attributes that can be computed from seismic data. Of course, if there is variation in the fundamental nat ure of.
New technologyseismicseismic interpretation august 9, 2007 hays, ks. Several crossplots shall be done, but the ones with the most significant discriminating power between lithofluid facies shall be used for analysis. 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. Throw away all the unnecessary attributes and what is left over is quite manageable. Notice the decrease in the elastic impedance value on the far angle stack. Reconnaissance surveys of 2d seismic data are acquired before most 3d seismic surveys to define the area of interest and regional trends. A twodimensional plot with one variable scaled in the vertical y direction and the other in the horizontal x axis. The pdf s which are applied to inverted seismic volumes honour the distribution of well log data in the lmr crossplot space figure 4.
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. Seismic attribute crossplots for example a plot of seismic amplitude, instantaneous phase and instantaneous frequency gives much information about reservoir properties. Obtain pertinent seismic attributes that could be used to characterize the. Seismic attributes are the components of the seismic data which are obtained by measurement, computation, and other methods from the seismic data. 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. Integrating surface seismic, microseismic, rock properties. The figures show the a crossplot between near and far ei logs, and b the zones on the logs. 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. The efficiency of seismic attributes to differentiate.
Using 3d seismic attributes in reservoir characterization 1. On the basis of resistivity maps and rock property versus seismicamplitude crossplots, we differentiated reservoirs in the lower taylor formation. 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. Lithology, rock properties were determined from the interceptgradient crossplot. Reliable estimation of petrophysical parameters is needed as input for such studies. 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. Extended elastic impedance and the avo crossplot whitcombe et al. Seismic attributes provide the seismic interpreter with new images that can enhance both the physical and geometric descriptions of the subsurface. 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. It has been applied much more widely in recent years and is now an important tool for many geoscientists. Porosities plot successively down the crossplot showing the dependency of acoustic impedance on porosity.
A petrel plugin to draw three dimensional crossplots from well and seismic data. Pdf using seismic attributes in petrophysical reservoir. Integrating seismic acoustic impedance inversion and. Facies probabilities from multidimensional crossplots of. Wellington field 3d seismic volume using the avo interceptgradient crossplotting technique. Seismic attributes fall into two broad categories those that help us quantify the morphological component. Bandwidth is a range of frequencies above a given amplitude threshold. Poststacked 3d seismic data, composite well logs, and velocity checkshot data were used for the reservoir analysis. Amplitudeversusoffset avo principles the amplitude character of seismic reflections varies with offset, due to changes in the angle of incidence.
When we crossplot v p v s ratio against pimpedance, the zone of low values of each. Simultaneous avo inversion of prestack data showed better. Hydrocarbon, reservoir, well logs, crossplotting, lithology. 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. Detecting stratigraphic features via crossplotting of. A judicious choice of opacity applied to edgesensitive attribute subvolumes, such as curvature or coherence, corendered with the seismic amplitude volume can. The porosity is estimated from the crossplot analysis between instantaneous amplitude attribute and the porosity log derived from the well location. Application of crossplot and prestack seismicbased. This capability is fully integrated with the kingdom platform to create a timeefficient. The attribute measurements are utilized to characterize the subsurface structure and depositional system such as fluvial dominated channels. 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. In modern seismic data interpretation, amplitude variation with offset it is. Seismic attributes are controlled by various components of the seismic wavelet including.
Seismic attribute analysis for reservoir characterization. The complex seismic trace attributes are found in some instances to correlate with lithological changes and historically have been used to characterize hydrocarbon reservoirs. 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 provides a preliminary insight into possible sources of shale anisotropy in nsa, thus enhancing the prospect of applying seismic anisotropy attributes amplitudeversus. Find and apply the type of filters you like to use in the drop down list. Reservoir characterization using seismic reflectivity and attributes. It helps in the prediction of reservoir characteristics away from well control points. Extended elastic impedance and its relation to avo. Avo analysis introduction avo preprocessing avo modeling avo parameters avo crossplot analysis avo attributes some application of avo probabilistic avo analysis.
The most recent papers have concentrated on reservoir characterization. Sequential geological modeling approach uses multiple seismic attributes as a. The derivation of net pay estimates from seismic attributes is a technology that has been around for quite a while brown et al, 1984. But no matter how new and sophisticated the algorithm, seismic pattern recognition rests on an old and simple foundation. In this example, area and twt are used to filter the data. Extended elastic impedance eei has proved to be a highly convenient framework for seismic avo studies. The seismic section top left hides prestack information.
Using 3d seismic attributes in reservoir characterization susan nissen geophysical consultant mclouth, ks kansas next step 2007 seminar. The porosity log data gives the porosity at the well location to be 25% 35%. Using the geodata investigator we can crossplot our angle stacks or intercept and gradient to get a quick look at any avo effect. Pdf seismic attributes and avo analysis by ahmed hafez. In elastic impedance inversion the seismic, model and output are as shown here. 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. On the right of the 2d color bar is the 1d color bar that you will load into your interpretation workstation.
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