Post stack inversion pdf

In this study the pre stack and post stack inversion. A study to assess the value of poststack seismic amplitude. There is a tradeoff between methodcosttime and quality of inversion results. Although post stack inversion is a powerful and robust method, it suffers from the fact that its final product, pimpedance.

The inversion methods are either deterministic or probabilistic and the approach can be post andor pre stack. It is also our goal to extend an earlier approach to post stack impedance inversion hampson and russell, 1991 so that this method can be seen as a generalization to the inversion of pre stack data. Feb 14, 2014 post stack migration was the standard up until the earlymid 1990s, usually in conjunction with dip moveout dmo, which is a partial pre stack time migration that has a weaker sensitivity to velocity. Poststack seismic inversion, developed in the 1970s, reverses the forward modeling procedure, allowing us to derive the impedance from the reflectivity. Pdf poststack seismic inversion and attribute analysis in shallow.

Correlation of avo inversion methods with porosity seen on logs and cores. Modelbased inversion, colored inversion, sparsespike inversion, bandlimited impedance inversion. A low frequency model was created from smoothed log data and cokriged with the migration seismic velocity. Post and prestack attribute analysis and inversion of. The pre stack method exploits avo effects on migrated cdp gathers.

Poststack stochastic inversion bualuang field, gulf of. Quantitative interpretation of co 2 plume from sleipner north sea, using post stack inversion and rock physics modeling. Impedance inversion was first accomplished and reported in lindseth 1979. A case study in the fort worth basin mathilde adelinet1, vincent clochard1, and patrice ricarte1. A case study for mississippian chert reservoir of oklahoma, usa. Different approaches have been used for poststack inversion, including bandlimited, sparsespike and modelbased, among others russell and hampson, 1991.

We found that the spatial continuity of permeability exhibited the. Sparsespike inversion of post stack seismic data of taranaki. Poststack and prestack inversion analyses were conducted, and the inversion parameters were calibrated to minimize residual between inverted and measured attributes. The prestack method exploits avo effects on migrated cdp gathers. Prestack inversion represents one step beyond poststack inversion in that not only the profile of acoustic impedance can be inferred from seismic data, rather a set of elastic parameters is estimated from prestack data i. Since the reflection coefficient depends only on the product of. Post stack deterministic and stochastic inversions post stack inversion improves lithology detection as the inverted seismic data better correlates with logs and can predict porosity. This example is of the same area of the gulf of mexico as shown in fig. Poststacklinearmodelling operator is used for modelling of both 1d and 2d synthetic poststack seismic data from a profile or 2d model of the.

The resulting impedance volume can be used to predict reservoir properties away from well control. Poststack inversion of the hussar low frequency seismic data. The pre stack and post stack seismic inversion is a proven method to provide general geological structure lithostratigraphy and information on distribution of. Pre stack and post stack inversion using a physics guided convolutional neural network reetam biswas and mrinal k. The second data set consists of a set of pre stack gathers and a single well. Effect of seismic wavelet phase on post stack inversion. Pdf in the present study, pre and poststack seismic inversions are performed to estimate subsurface petrophysical properties from the. Pdf quantitative interpretation of co 2 plume from sleipner. Poststack inversion is the most common quantitative geophysical application in reservoir characterization. From poststack inversion, the outcome is usually acoustic impedance, whereas.

Poststack multiazimuth stratigraphic inversion applied. Low frequency background model ai generation pwave impedance logs are sub sampled into a microlayer model whose boundaries are defined by the key reservoir. Results and discussion the post stack inversion products were zp and pre stack. Lithology characterisation of the roof and floor of the. These attributes help to understand lithology and fluid contents in the subsurface. Poststack and prestack avo inversion were performed for the hussar data to study the role of using very low frequencies seismic data and initial background. A typical poststack processing sequence includes the following steps. Avo, inversion and attributes in seismic interpretation enhance your capability in seismic data interpretation with modern avo and inversion techniques limited ipad 2. Post stack inversion of reflection data in seismic exploration can be used to obtain detailed information about lithology variations in the zone of interest.

The first type of inversion, velocity inversion, sometimes known as traveltime inversion, is used for depth imaging. Poststack multiazimuth stratigraphic inversion applied to. Pre stack inversion transforms seismic angle or offset data into pimpedance, simpedance and density volumes through integration of the seismic angleoffset gathers, well data and a basic stratigraphic interpretation. The methods are post stack inversion, the elastic impedance, and the pre stack inversion and avo attributes.

Bulletin of earth sciences of thailand priyanto, seismic inversion in the songkhla basin. Apr 19, 2016 learn how to perform a post stack ai inversion using the new workflows option in hrs9. Pdf comparison of poststack seismic inversion methods. The inversion results in acoustic impedance ai, which is the product of rock density and pwave velocity. Post stack seismic impedance and amplitude inversion confusion. The inversion methods are either deterministic or probabilistic and the approach can be post andor prestack. Correlation of avo inversion methods with porosity seen on.

Prestack avo and poststack inversion of the hussar low. The geosi method that i will discuss today combines both a gaussian pdf and. We make use of geostatistical inversion to construct spatial distributions of porosity and permeability that simultaneously honor well logs and poststack seismic. The old and the new in seismic inversion cseg recorder. Part 2 poststack inversion 22 introduction inversion is the process of extracting, from seismic data, the underlying geology which gave rise to that seismic. Pre stack inversion and avo attributes give reasonable results in cross sections. Summary in this paper, we present a new approach to the simultaneous pre stack inversion of pp and, optionally, ps angle gathers for the estimation of pimpedance, simpedance and density.

Pre stack inversion and avo attributes give reasonable results in cross sections near the. It also is often effective in suppressing reverberations and shortperiod multiples. Pdf comparing pre and post stack seismic inversion. Seismic inversion can be divided into two techniques which are post stacking and prestacking inversion. Inversion of seismic data is a process to produce an estimate of earths acoustic impedance. Seismic inversion methods and some of their constraints. In contrast to the use of marine seismic reflection techniques for reservoirscale applications, where seismic inversion for quantitative sediment analysis is common, shallowwater, veryhighresolution seismic reflection data are seldom used for. Inversion schemes generally use migrated time data as basic input. This technique transforms a single seismic information volume into an acoustic impedance volume by using seismic data, well data, and basics. As amplitude variations for different anglesoffsets are modeled during the inversion and not averaged in the stacking process, usually the pimpedance inversion is improved.

Deconvolution after stack field data examples is usually applied to restore high frequencies attenuated by cmp stacking. This technique transforms a single seismic information. Pre stack inversion represents one step beyond post stack inversion in that not only the profile of acoustic impedance can be inferred from seismic data, rather a set of elastic parameters is estimated from pre stack data i. Comparison of post stack seismic inversion methods. Newer methods analyze pre stack data, where the analysis of the amplitudes without inversion is called amplitude versus offset, or avo. To show the connection between the pre and post stack formulations more clearly, fatti et al. Stochastic vs deterministic pre stack inversion methods. Poststacklinearmodelling operator is used for modelling of both 1d and 2d synthetic poststack seismic data from a profile or 2d model of the subsurface acoustic impedence. Pdf seismic inversion methods and some of their constraints. Durham etheses poststack inversion of seismic re ection.

Seismic inversion poststacking vs prestacking seg wiki. Pdf comparing pre and post stack seismic inversion methods a. In this talk i will discuss these methods and look at their assumptions and. Compared with post stack inversion an additional dimension is available for lithology and fluid fill discrimination. Earthworks seismic inversion plugin for decisionspace. Waveform inversion is the category that includes all post migration reflection seismic inverse problems where the input is a single trace or an offset gather constant x,y for all input reflections. Figure 1 shows flowchart of seismic inversion methods. Poststack inversion transforms a single seismic data volume into acoustic impedance through integration of the seismic data, well data and a basic stratigraphic interpretation. And when i use a, its work, but i want do this in the. Sen department of geological sciences the university of texas at austin abstract an inversion algorithm is commonly used to estimate the elastic properties like v p, v s, r of the earths subsurface.

Pdf deriving shallowwater sediment properties using. The first consists of a 3d seismic volume and wells. Poststack seismic impedance and amplitude inversion confusion. Pdf comparison of post stack seismic inversion methods. A comparison of inversion techniques for estimating vpvs. Post stack inversion method the process of estimating vpvs with a post stack inversion method follows the.

An example of a poststack seismic resolution inversion technique is the constrained sparsespike inversion cssi. Pdf deriving shallowwater sediment properties using post. The inversion analysis shows that with low cut filter of hz, we still obtain reasonable inverted results with minimal residual between measured and inverted results. Poststack seismic inversion, developed in the 1970s, reverses the forward. The milton dobrin lecture april, 2010 brian russell hampsonrussell. Some of the advantages of post stack inversion methods are mentioned below. The inversion methods are implemented on the post stack seismic data. 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. Flow chart of inversion methods used in this study. Unlike seismic reflection data which is an interface property ai is a rock property. This tutorial takes you through the entire process of inverting two data sets. Post stack inversion of the hussar low frequency seismic data.

Different approaches have been used for post stack inversion, including bandlimited, sparsespike and modelbased, among others russell and hampson, 1991. Seismic data may be inspected and interpreted on its own without inversion, but this does not provide the most detailed view of the subsurface and can be. Poststack inversion provides acoustic impedance information ip, often assuming zerooffset reflectivity. Similarly, simultaneous inversion was performed to. Avo, inversion and attributes in seismic interpretation. A profitable development of an oil or gas field starts with a good understanding of the subsurface as a basis for efficient and successful field management. Pre stack inversion has many forms, where the major division is between deterministic and stochastic, or geostatistical, methods. Simultaneous inversion of pre stack seismic data dan hampson, brian russell, hampsonrussell software, brad bankhead, veritasdgc. The purpose of my investigation is to apply gli to data from the coal measures. This assumes a limited number of reflection coefficients, with larger amplitude. Using seismic traces at widely spaced locations, it generates a velocitydepth earth model that fits recorded arrival times of seismic. Part 2 post stack inversion 22 introduction inversion is the process of extracting, from seismic data, the underlying geology which gave rise to that seismic.

Pdf quantitative interpretation of co 2 plume from. Learn how to perform a post stack ai inversion using the new workflows option in hrs9. The elastic impedance also gives results similar to the post stack inversion. Both post and pre stack inversion require quite a bit of processing to prepare the data, including velocity analysis to flatten common midpoint gathers. 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. Poststack inversion methods include sparse spike inversion. We estimate the pimpedance from the post stack data by way of model based inversion as well as neural network analysis.

This is to be expected, since the amplitudes used in the post stack inversion were increased due to the avo effect. Stochastic vs deterministic prestack inversion methods cgg. Seismic inversion of the hussar data pre stack avo and post stack inversion of the hussar low frequency seismic data a. Malleswar moe yenugu, kurt j marfurt, university of oklahoma. Request pdf sparsespike inversion of post stack seismic data of taranaki basin, new zealand in this study, a seismic inversion using sparsespike method was undertaken to predict the. Modelbased mbi, colored ci, sparsespike ssi, and bandlimited bli inversions are applied to the poststack seismic data from the blackfoot field, alberta. Poststack inversion estimating subsurface properties from bandlimited seismic data represents an important task for geophysical subsurface characterization.

Abstract post stack and pre stack avo inversion were performed for the hussar data to study. Joint prestack inversion of the pwave gathers and a converted wave volume the procedure and results from that analysis are presented below. Traditionally, inversion has been applied to post stack seismic data, with the aim of extracting acoustic impedance. Poststack seismic impedance and amplitude inversion.

In this tutorial, we have discussed the history of seismic amplitude inversion, from its origin as a post stack process to the most recent developments which involves the simultaneous inversion of pre stack seismic data. This version of earthworks seismic inversion for decisionspace will also run with the 5000. Generalized linear inversion gli has previously been applied as a useful tool to achieve this. I dont find understand how send a simple pdf file by post request at a webservice rest protocol. Unlike seismic reflection data which is an interface property ai is. Application of seismic poststack inversion for gas. The objective of this research is to use several standard seismic post stack inversion methods for. Different between poststackprestack seismic inversion. To further guide interpolation and extrapolation of the log data within the model the top coal horizon was also used. 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. View the article pdf and any associated supplements and figures for a period of 48 hours.

Charles wickstrom and shane matson, spyglass energy. This process is necessary to overcome the limitations of geophysical methods imposed by areas of complex geology. The first technique, post stacking inversion is the most common approach used for inversion. Using ai and log property attribute relationships as input, our output sections can be scaled to porosity or could be used to differentiate between sands and shales. A study to assess the value of poststack seismic amplitude data in. The inverted pimpedance from the simultaneous inversion of the pre stack data in figure 5 is shown in figure 8, and displays less of an impedance drop than the modelbased post stack inversion shown in figure 4. Post stack multiazimuth stratigraphic inversion applied to unconventional reservoir characterization. A map of the seismic data identifying the relative positions of the wells is provided in figure 1. The results of trace inversion can be used to identify spatially distinct bodies with specific impedance ranges. Other combinations of elastic parameters such as pimpedance, vpvs ratio and density are equally possible. Inversion methodsacasestudyfromblackfootfield,canada. The typical workflow for either poststack or prestack inversion consists of the following steps. An example of a post stack seismic resolution inversion technique is the constrained sparsespike inversion cssi.