Deconvolution after stack field data examples is usually applied to restore high frequencies attenuated by cmp stacking. After processing 3d seismic data by using promax and geotomo softwares and giving a clear image, the data is ready to the inversion. Sensitivity analysis of pre stack seismic inversion on. Most seismic attributes are post stack, but those that use cmp gathers, such as amplitude versus offset avo, must be analysed pre stack. Prestack time migration and post stack depth migration. Data around two wells, one with 6% porosity and the other one with tight, bedded dolomite. Article details prestack and poststack data compression. Estimation of the gashydrate resource volume in a small.
Seismic attributes for reservoir studies petrowiki. A post stack attribute that measures the continuity between seismic traces in a specified window. Over a time window on each trace independently such as root mean square rms amplitude over 24 ms. The chapters of the book build upon each other and progress from basic. Examples from the outer fold and thrust belt, deepwater niger delta joint development zone. The concept of complex traces was first described by tanner, 1979. Avo analysis, followed by post stack inversion of the avo attributes goodway, et al. The petrel prestack seismic interpretation plugin enables prestack seismic visualization, interpretation, and interactive processing to bridge the gap between prestack and poststack interpretation workflows. Seismic facies analysis is usually implemented by using post stack data. 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. Poststack attribute analysis of the 9c seismic survey. At the end of the day, geoscientists and interpreters want to. The attribute is a result of the properties derived from the complex seismic signal. The handbook of poststack seismic attributes is a general reference for poststack seismic attributes.
This process is necessary to overcome the limitations of geophysical methods imposed by areas of complex geology. Attributes are secondary properties derived from prestack reflection data or more often from the images themselves. Enhanced delineation of reservoir compartmentalization from. 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. The objectives of the application of noise attenuation and spectral shaping were as follows. A seismic example the seismic line is the stack of a series of cmp gathers, as shown here.
Seismic attributes are essentially derivatives of the basic seismic measurements i. Arturo soto cuervo3 and drs paul veeken4 1 cgg, 1 rue leon migaux, 941 massy, france 2 fusion pt, 25231 grogans mill rd s175, the woodlands tx77380, usa 3 pemex, boca del rio, veracruz, mexico. Application of volumetric seismic attributes to delineate fault geometry. Pdf fractured reservoir characterization using poststack. Pre stack inversion and avo attributes give reasonable results in cross sections. Marcio spinola, raphael melo and carlos henrique and juan soldo event name. Comparison of post stack seismic inversion methods. The methods are poststack inversion, the elastic impedance, and the prestack inversion and avo attributes. On the other hand, additional information can be obtained from attributes of the individual seismic traces prior to stacking, in a prestack analysis. 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. Poststack attribute analysis olds, alberta crewes research report volume 9 1997 373 method the objective of this work is twofold. The upper image in figure 2 presents acoustic impedances obtained with the full post. It also is often effective in suppressing reverberations and shortperiod multiples. Through the integration of selected seismic attributes with poststack stochastic seismic inversion reservoir distributions and architectures are accurately delineated for the upper cretaceous.
Crossplotting attributes such as avo gradient and intercept, usually derived from common depthpoint gathers, is a simple and effective analysis tool. Kingdom seismic and geological interpretation software ihs. A typical poststack processing sequence includes the following steps. Avo, inversion and attributes in seismic interpretation. This research presents a workflow integrating several poststack seismic attributes to assist in understanding the development history of weirman field, ness. The first technology will show how the use of post stack seismic in an. Porosity mapping from inversion of poststack seismic data b. Pdf comparison of post stack seismic inversion methods.
Comparative analysis between prestack and poststack. 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. Fractured reservoir characterization using poststack. At each point on the seismic trace independently such as amplitude. Post stack velocity analysis by separation and imaging of seismic di ractionsa apublished in geophysics, 72, u89u94, 2007 sergey fomel, evgeny landay, and m. This paper will present two technologies where 3d seismic attributes along with geologic and engineering data are being used to characterize fractured reservoirs. Poststack seismic data processing generate fault, seismic and rock solid attributes, and despike, resample and flatten seismic data. Lines abstract there are a variety of methods that can be used to extract rockproperties information from seismic data. That is, an energy source is used to generate a pulse of acoustic energy and direct it into the ground. 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.
First, reflectivity and acoustic impedance profiles are obtained from the inversion of poststack seismic data. The handbook of poststack seismic attributes is a general reference for poststack seismic attributes intended for reflection seismologists in petroleum exploration. Both post and pre stack inversion require quite a bit of processing to prepare the data, including velocity analysis to flatten common midpoint gathers. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to combinations of these. Attributes may be further classified by their computational characteristics. Fractured reservoir characterization using post stack seismic attributes. Dominguez1 discuss the use of post stack 3d seismic data to quickly define a relative fracture density attribute and discrete fracture imaging. Post stack attributes are a more manageable approach for observing large amounts of data in initial reconnaissance investigations. This assumes a limited number of reflection coefficients, with larger amplitude. Total depth have undertaken the task of building a database of preinterpreted projects from southern australia. Handbook of poststack seismic attributes geophysical references. Introduction the ability to determine the relative density and orientations of. 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. Prestack and poststack data compression and its impact.
Pre stack time migration and post stack depth migration. This process, called seismic inversion for reservoir characterization, can help fill gaps in our knowledge of formation properties between wells. Seismic analysis interpret in time or depth on 2d3d survey inlines, crosslines, zslices, arbitrary lines and 3d space. Poststack seismic inversion and attribute analysis in. Featurescost savings, reduced interpretation cycle time post stack seismic data enhancements and attribute generation from your seisworks session eliminates the cost and time of sending the data out of house for reprocessing. Reservoir characterization using seismic reflectivity and attributes. Poststack seismic inversion and attribute analysis in shallow. For detailed studies, pre stack attributes may be incorporated. Seismic imaging is a general term that geophysicists now use to describe processes that convert seismic data into a geological representation of the subsurface. Handbook of poststack seismic attributes geoscienceworld.
Prestack and poststack data compression and its impact on. This method is applied on seismic wave form and instantaneous attributes. What are the key issues a practical categories of seismic attributes. It can be used to map the lateral extent of a formation.
Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to. 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. Kingdom seismic and geological interpretation software. It can also be used to see faults, channels or other discontinuous features. Post and pre stack attribute analysis and inversion of teapot dom 3d seismic dataset kamal abo jnah and igor b. An example of a post stack seismic resolution inversion technique is the constrained sparsespike inversion cssi. 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. 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.
Poststack application of noise attenuation and spectral. These methods use colored inversion, model based inversion and sparse spike derived impedances as external attributes and seismic and well log data as internal attributes for the geostatistical analysis. Lithology characterisation of the roof and floor of the. Enhanced delineation of reservoir compartmentalization. Post stack seismic data processing generate fault, seismic and rock solid attributes, and despike, resample and flatten seismic data. Even today, compressed seismic files make storage and management of large original volumes highly practical. Pdf quantitative use of seismic attributes for reservoir. These attributes help to understand lithology and fluid contents in the subsurface. Pdf poststack seismic inversion and attribute analysis in shallow. Post stack attributes post stack attributes are derived from the stacked data. Poststack attributes post stack attributes are derived from the stacked data.
Instantaneous local amplitudes, phases, frequencies, bandwidths, etc. Prestack and poststack data compression and its impact on seismic attributes. To construct seismic sections after common processing steps, the data from different offsets are stacked together. A post stack attribute that measures the continuity between seismic traces in a specified window along a picked horizon. The use of seismic attributes to enhance fault interpretation. 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. Seismic facies analysis from prestack data using self.
First off, all reflection seismic data is recorded in time whether onshore or offshore. Porosity mapping from inversion of poststack seismic data. Quicklook avo crossplotting from poststack seismic data. Poststack attribute analysis of the 9c seismic survey olds. Pre stack and post stack data compression and its impact on seismic attributes. Post stack attributes are derived from the stacked data. Post stack attribute based fracture characterization.
Jul 06, 2014 poststack attributes post stack attributes are derived from the stacked data. Spectral attributes were also extracted from the poststack seismic data. Impact of prestack and poststack seismic on integrated. The complex seismic trace attributes are found in some instances to correlate with lithological changes and historically have been used to characterize hydrocarbon reservoirs. Seismic attribute analysis for reservoir characterization. Prestack event interpretation uses a true 4d tracker, seeded from gather picks and horizons. 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. 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. A comparison of inversion techniques for estimating vpvs. 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. This included a full kirchhoff prestack time migration, detailed velocity analysis and. Comparative analysis between prestack and poststack seismic. 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. Seismic attributes seismic interpretation often relies on attribute sections and 3d images.
The pimpedance attributes derived from post stack seismic inversion utilized with the distributed petrophysical properties density predict the occurrence probability of the distinctive. Post and prestack attribute analysis and inversion of. Here is a portion of a 2d seismic line showing a gas sand brightspot. R eservoir compartmentalization has a huge bearing on fluid flow within hydrocarbon reservoirs, and can impact overall recovery during field development. Poststack multiazimuth stratigraphic inversion applied to. It discusses their theory, meaning, computation, and application, with the goal of improving understanding so that seismic attributes can be applied more effectively. Pdf comparing pre and post stack seismic inversion.
Attributes can be obtained from typical post stack seismic data volumes, and these are the most common types. Pdf in the present study, pre and poststack seismic inversions are performed to estimate subsurface petrophysical properties from the seismic. Fractured reservoir characterization using poststack seismic attributes. The drilling expeditions in the ulleung basin in 2007 and 2010 recovered gas hydrates at water. The post stack seismic data available from openfile sources was reprocessed using noise attenuation and spectral shaping techniques. 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. The elastic impedance also gives results similar to the post stack inversion. The objective of this research is to use several standard seismic post stack inversion methods for. Seismic attributes are defined as all the information obtained from seismic data, either by direct measurements or by logical or experience based reasoning 1.
Different between poststackprestack seismic inversion. However, prestack seismic data are not always part of the seismic interpreters basic dataset and are often expensive to store and timeconsuming to procure. Using seismic attributes in seismotectonic research solid earth. 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. Access free seismic attributes analysis wikipedia attributes based on stacked data post stack attributes can be computed. After the most appropriate gamma ray and porosity models were chosen, pay zone maps. Impact of pre stack and post stack seismic on integrated naturally fractured reservoir characterization. The inversion results in acoustic impedance ai, which is the product of rock density and pwave velocity. For estimation of seismic attributes any of the following can be used as input. Seismic attributes and their applications in seismic.
534 1197 72 222 1039 1454 656 1137 278 1272 1255 1242 143 242 1216 1591 139 54 221 1249 1230 1123 629 578 429 1669 340 353 1213 70 102 1176 1219 1483 1099 713 565 999 489 565 381 927 267 364