The petrel prestack seismic interpretation plugin enables prestack seismic visualization, interpretation, and interactive processing to bridge the gap between prestack and poststack interpretation workflows. Both post and pre stack inversion require quite a bit of processing to prepare the data, including velocity analysis to flatten common midpoint gathers. On the other hand, additional information can be obtained from attributes of the individual seismic traces prior to stacking, in a prestack analysis. Post and pre stack attribute analysis and inversion of teapot dom 3d seismic dataset kamal abo jnah and igor b. Porosity mapping from inversion of poststack seismic data b. Impact of pre stack and post stack seismic on integrated naturally fractured reservoir characterization. Enhanced delineation of reservoir compartmentalization. The first technology will show how the use of post stack seismic in an. The elastic impedance also gives results similar to the post stack inversion.
Estimation of the gashydrate resource volume in a small. Enhanced delineation of reservoir compartmentalization from. The complex seismic trace attributes are found in some instances to correlate with lithological changes and historically have been used to characterize hydrocarbon reservoirs. Post stack seismic data processing generate fault, seismic and rock solid attributes, and despike, resample and flatten seismic data. This process, called seismic inversion for reservoir characterization, can help fill gaps in our knowledge of formation properties between wells.
Through the integration of selected seismic attributes with poststack stochastic seismic inversion reservoir distributions and architectures are accurately delineated for the upper cretaceous. Sensitivity analysis of pre stack seismic inversion on. First off, all reflection seismic data is recorded in time whether onshore or offshore. Introduction the ability to determine the relative density and orientations of. Most seismic attributes are post stack, but those that use cmp gathers, such as amplitude versus offset avo, must be analysed pre stack. For estimation of seismic attributes any of the following can be used as input. Seismic facies analysis from prestack data using self. Post stack velocity analysis by separation and imaging of seismic di ractionsa apublished in geophysics, 72, u89u94, 2007 sergey fomel, evgeny landay, and m.
Seismic facies analysis is usually implemented by using post stack data. Lithology characterisation of the roof and floor of the. Pdf in the present study, pre and poststack seismic inversions are performed to estimate subsurface petrophysical properties from the seismic. Handbook of poststack seismic attributes geophysical references. Comparative analysis between prestack and poststack seismic. The objective of this research is to use several standard seismic post stack inversion methods for. First, reflectivity and acoustic impedance profiles are obtained from the inversion of poststack seismic data. In the present study, pre and post stack seismic inversions are performed to estimate subsurface petrophysical properties from the seismic reflection data, obtained over the penobscot field, canada. The drilling expeditions in the ulleung basin in 2007 and 2010 recovered gas hydrates at water. Different between poststackprestack seismic inversion. Seismic inversion methods have been routinely used for estimating attributes like pimpedance, simpedance, density, ratio of pwave and swave velocity and elastic impedances from seismic and well log data. Post and prestack attribute analysis and inversion of. Impact of prestack and poststack seismic on integrated.
Poststack attribute analysis of the 9c seismic survey olds. Over a time window on each trace independently such as root mean square rms amplitude over 24 ms. Instantaneous local amplitudes, phases, frequencies, bandwidths, etc. An example of a post stack seismic resolution inversion technique is the constrained sparsespike inversion cssi. Comparison of post stack seismic inversion methods. Seismic attributes are defined as all the information obtained from seismic data, either by direct measurements or by logical or experience based reasoning 1. Individual seismic attributes give us indications of many subtle properties, however the real enhancement in predictive accuracy and reliability of results comes from combining multiple seismic attributes and solving the nonlinear relationship between the seismic attributes and reservoir properties. Marcio spinola, raphael melo and carlos henrique and juan soldo event name. Seismic attributes for reservoir studies petrowiki analysis of attributes has been integral to reflection seismic interpretation since the 1930s when geophysicists started to pick traveltimes to coherent reflections on seismic field records. Impedance data is a key attribute for predicting reservoir properties from seismic. Using seismic attributes in seismotectonic research solid earth. Seismic migration is the process by which seismic events are geometrically relocated in either space or time to the location the event occurred in the subsurface rather than the location that it was recorded at the surface, thereby creating a more accurate image of the subsurface.
Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to. At the end of the day, geoscientists and interpreters want to. A post stack attribute that measures the continuity between seismic traces in a specified window along a picked horizon. After the most appropriate gamma ray and porosity models were chosen, pay zone maps.
Post stack attribute based fracture characterization. Application of volumetric seismic attributes to delineate fault geometry. Poststack application of noise attenuation and spectral. Reservoir characterization using seismic reflectivity and attributes. The handbook of poststack seismic attributes is a general reference for poststack seismic attributes intended for reflection seismologists in petroleum exploration.
Prestack and poststack data compression and its impact on. A typical poststack processing sequence includes the following steps. 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. Post stack attributes post stack attributes are derived from the stacked data.
These representations may vary from simple structural images that use migration algorithms, to ones that estimate rock properties with algorithms that are based on inversion. Fractured reservoir characterization using poststack. The inversion results in acoustic impedance ai, which is the product of rock density and pwave velocity. Even today, compressed seismic files make storage and management of large original volumes highly practical. Poststack multiazimuth stratigraphic inversion applied to.
Spectral attributes were also extracted from the poststack seismic data. Seismic analysis interpret in time or depth on 2d3d survey inlines, crosslines, zslices, arbitrary lines and 3d space. Pdf comparing pre and post stack seismic inversion. The use of seismic attributes to enhance fault interpretation. Turhan tanerz abstract small geological features manifest themselves in seismic data in the form of di racted waves, which are fundamentally di erent from seismic re ections. Seismic attributes and their applications in seismic. The post stack seismic data available from openfile sources was reprocessed using noise attenuation and spectral shaping techniques. Anelastic attenuation factor the anelastic attenuation factor or q is a seismic attribute that can be determined from seismic reflection data for both reservoir characterisation and advanced seismic processing. Pdf poststack seismic inversion and attribute analysis in shallow.
It also is often effective in suppressing reverberations and shortperiod multiples. What are the key issues a practical categories of seismic attributes. Pre stack time migration and post stack depth migration. Handbook of poststack seismic attributes geoscienceworld. However, pre stack seismic data are not always part of the seismic interpreters basic dataset and are often expensive to store and timeconsuming to procure. This article describes the science and art of seismic inversion, and how oil and gas companies are using it to reduce risk in their exploration.
It can also be used to see faults, channels or other discontinuous features. Kingdom seismic and geological interpretation software. The methods are poststack inversion, the elastic impedance, and the prestack inversion and avo attributes. Pre stack and post stack data compression and its impact on seismic attributes. Prestack event interpretation uses a true 4d tracker, seeded from gather picks and horizons.
Comparative analysis between prestack and poststack. To construct seismic sections after common processing steps, the data from different offsets are stacked together. That is, an energy source is used to generate a pulse of acoustic energy and direct it into the ground. Fractured reservoir characterization using post stack seismic attributes. Poststack seismic data processing generate fault, seismic and rock solid attributes, and despike, resample and flatten seismic data.
It can be used to map the lateral extent of a formation. Quicklook avo crossplotting from poststack seismic data. Prestack and poststack data compression and its impact. Post stack attribute analysis olds, alberta crewes research report volume 9 1997 371 poststack attribute analysis of the 9c seismic survey olds, alberta vladan simin abstract seismic attribute analysis was performed on the olds 9c2d line. The chapters of the book build upon each other and progress from basic. However, prestack seismic data are not always part of the seismic interpreters basic dataset and are often expensive to store and timeconsuming to procure. With the multiplication of seismic data being generated each year for exploration and reservoir purposes, storage and management of pre stack and post stack seismic files are still a challenge for infrastructure management. A seismic example the seismic line is the stack of a series of cmp gathers, as shown here. The pimpedance attributes derived from post stack seismic inversion utilized with the distributed petrophysical properties density predict the occurrence probability of the distinctive. Seismic attributes seismic interpretation often relies on attribute sections and 3d images. Access free seismic attributes analysis wikipedia attributes based on stacked data post stack attributes can be computed.
Seismic attributes are essentially derivatives of the basic seismic measurements i. Here is a portion of a 2d seismic line showing a gas sand brightspot. Poststack seismic inversion and attribute analysis in. Poststack attribute analysis olds, alberta crewes research report volume 9 1997 373 method the objective of this work is twofold. Kingdom seismic and geological interpretation software ihs. A comparison of inversion techniques for estimating vpvs. Prestack and poststack data compression and its impact on seismic attributes. This research presents a workflow integrating several poststack seismic attributes to assist in understanding the development history of weirman field, ness. Seismic imaging is a general term that geophysicists now use to describe processes that convert seismic data into a geological representation of the subsurface. These attributes help to understand lithology and fluid contents in the subsurface. R eservoir compartmentalization has a huge bearing on fluid flow within hydrocarbon reservoirs, and can impact overall recovery during field development. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to combinations of these. Chatterjee indian institute of technology indian school of mines, dhanbad, india a seismic section oriented ns passing through well w is considered for porosity prediction in bstract.
Poststack attributebased fracture characterization. Fractured reservoir characterization using poststack seismic attributes. This process is necessary to overcome the limitations of geophysical methods imposed by areas of complex geology. After processing 3d seismic data by using promax and geotomo softwares and giving a clear image, the data is ready to the inversion. The goal of the book is to bring greater understanding and order to the important and rapidly evolving science of seismic attributes, so that geophysicists can apply attributes more. Attributes can be obtained from typical post stack seismic data volumes, and these are the most common types. Poststack seismic inversion and attribute analysis in shallow. This paper will present two technologies where 3d seismic attributes along with geologic and engineering data are being used to characterize fractured reservoirs. Jul 06, 2014 poststack attributes post stack attributes are derived from the stacked data. For detailed studies, pre stack attributes may be incorporated. This assumes a limited number of reflection coefficients, with larger amplitude. Deconvolution after stack field data examples is usually applied to restore high frequencies attenuated by cmp stacking.
It discusses their theory, meaning, computation, and application, with the goal of improving understanding so that seismic attributes can be applied more effectively. Prestack time migration and post stack depth migration. Seismic attributes for reservoir studies petrowiki. Total depth have undertaken the task of building a database of preinterpreted projects from southern australia. Post stack attributes are derived from the stacked data. Post stack attributes are a more manageable approach for observing large amounts of data in initial reconnaissance investigations. Post stack inversion estimates acoustic impedance using individual seismic traces, while pre stack inversion estimates elastic parameters using a linear model of amplitude versus offset.
Avo, inversion and attributes in seismic interpretation. Examples from the outer fold and thrust belt, deepwater niger delta joint development zone. Pdf fractured reservoir characterization using poststack. Attributes may be further classified by their computational characteristics. Attributes are secondary properties derived from prestack reflection data or more often from the images themselves. Lines abstract there are a variety of methods that can be used to extract rockproperties information from seismic data. This included a full kirchhoff prestack time migration, detailed velocity analysis and. The objectives of the application of noise attenuation and spectral shaping were as follows. Crossplotting attributes such as avo gradient and intercept, usually derived from common depthpoint gathers, is a simple and effective analysis tool.
Poststack attribute analysis of the 9c seismic survey. Poststack attributes post stack attributes are derived from the stacked data. This method is applied on seismic wave form and instantaneous attributes. Pdf quantitative use of seismic attributes for reservoir. The concept of complex traces was first described by tanner, 1979. The handbook of poststack seismic attributes is a general reference for poststack seismic attributes. Article details prestack and poststack data compression. Pre stack inversion and avo attributes give reasonable results in cross sections. Pdf comparison of post stack seismic inversion methods.
Seismic attribute analysis for reservoir characterization. A post stack attribute that measures the continuity between seismic traces in a specified window. The attribute is a result of the properties derived from the complex seismic signal. At each point on the seismic trace independently such as amplitude.
552 1512 238 1182 1532 1266 1306 914 69 558 826 687 1057 1601 525 1307 1456 1606 581 1463 1491 365 437 718 412 875 320 861 363 684 1252 1055 76 1483 759 557 82