The first is bandlimited inversion, in which a scaled relative impedance from the seismic data is mixed with a low frequency element from the model. This suggests a general approach to the seismic inversion method, as shown in figure 1. The main objective of this method is to map the structures of subsurface formations in order to infer the existence of possible petroleum traps. Crains petrophysical handbook seismic inversion basics. Used to image and analyze reservoir changes in pressure and fluid saturation to optimize hydrocarbon recovery. Essentially, geostatistical inversion methods as in 79, perform a sequential approach in two steps. The earths reflectivity can be considered fractal, and the resulting amplitude spectrum favors high frequencies spectral blueing.
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. Since seismic linear inversion is a deterministic inversion method, the stochastic method will not be discussed beyond this point. His book introduction to seismic inversion methods, based on course notes from an seg continuing education course, was published by the society of exploration geophysicists in 1988. This book introduces readers to seismic inversion methods and their application to both synthetic and real seismic data sets. Colored inversion is designed to approximately match the average spectrum of inverted seismic data with the average spectrum observed impedance lancaster and whitcombe, 2000. Recursive inversion practice introduction to seismic. Preconditioning of seismic data prior to impedance inversion, published in aapg explorer. In the past sections of the course, we have derived reflectivity information directly from the seismic section and used recursive inversion to produce a final velocity versus depth model. Introduction to seismic inversion methods course notes series. Welltoseismic match, zerophasing of data in zone of interest and extraction of the wavelet. While seismic migration is aimed at imaging the reflectors or the interfaces at their correct subsurface locations, seismic inversion attempts to estimate elastic and flow properties of the layers.
Introduction to seismic inversion methods book, 1988. The most basic inversion calculates acoustic impedance density x. A broad meaning of seismic inversion commonly referred to as elastic inversion, is the grand scheme of estimating elastic parameters directly from observed data. More than 50 million people use github to discover, fork, and contribute to over 100 million projects. In the earth, seismic waves can propagate as longitudinal p or as shear s waves. Full waveform tomography is a tomographic technique that takes advantage of numerical solutions of the elastic wave equation. The seismic data are simply assumed to fit the forward model and is inverted using the inverse relationship. P and simpedance inversion, lambdamurho, elastic impedance and poisson impedance. Ritesh kumar sharma, arcis seismic solutions, calgary. Avo and prestack seismic inversion methods can be understood.
Do not copy or distribute in any form without explicit permission. Quality control and preconditioning of the input data. Basic principles of the seismic method tu delft ocw. This article is based on crains seismic petrophysics by e. On the left side of this flowchart, the input is our best. The primary application is for inverting reflection andor transmission data from engineering or exploration surveys, but the methods described also can be used for earthquake studies. This book explains all popular seismic inversion methods and their mathematical background together, demonstrates their capacity to extract information from. An overview of techniques used in the inversion of seismic data is provided. Seismic inversion the best tool for reservoir characterization.
Inverse modeling is a mathematical technique where the objective is to determine the physical. Introduction to seismic inversion methods course notes. Inversion is defined as mapping the physical structure and properties of the subsurface of the earth using measurements made on the surface, creating a model of the earth using seismic data as input. The wave phenomena occurring at a boundary between two layers are discussed, such as snells. Deterministic inversion is a method whereby an observed data set and some known basic model generally a set of ordinary or partial differential e. Seismic inversion, in geophysics is the process of transforming seismic reflection data into a.
Bandlimited inversion is a robust method that produces a smooth and continuous output. This book follows an alternative approach to extracting information from seismic data by invoking inverse scattering theory. Avo and seismic inversion a profitable development of an oil or gas field start with a good understanding of the subsurface as a basis for efficient and successful field management. An overview of the current techniques used in the inversion of seismic data is provided. Interwell is a seismic inversion and characterization software for reservoir and exploration geophysicists, available in linux and windows environments. Hamood, there are basically two types of inversion of data. The use of avo and inversion techniques helps to create the. Enhancing the quality of seismic impedance data, published in aapg explorer. Reservoir characterization using avo and seismic inversion. The second approach is modelbased inversion technique russell and hampson, 1991. This webpage version is the ed intellectual property of the author. A classification scheme for avo and prestack seismic inversion methods.
Recursive inversion theory introduction to seismic. Seismic inversion for reservoir properties rithms and simulated annealing for seismic inversion. Seismic inversion methods are routinely used to estimate attributes like pimpedance, simpedance, density, the ratio of pwave and swave velocities and elastic impedances from seismic and well log data. Crains petrophysical handbook seismic amplitude versus. All modern seismic inversion methods require seismic data and a wavelet estimated from the data. This book describes the theory and practice of inverting seismic data for the subsurface rock properties of the earth. Introduction to seismic inversion methods course notes ser. Stochastic and deterministic seismic inversion methods for. Introduction to seismic inversion methods course notes series, no.
Inversion transforms seismic reflection data into rock and fluid properties. This overview attempts to summarize the most common terminology and inversion approaches. Seismic inversion and synthetic sonic logs calibration of seismic attributes to ground truth is still an emerging science. Other combinations of elastic parameters such as pimpedance, vpvs ratio and density are equally possible. Introduction introduction to seismic inversion methods. Machine learning isnt just useful for computing in the inverse direction such as with inversion, seismic interpretation, and so on. Azza mahmoud abd ellatif elrawy lecturer of geophysics geophysics department faculty of science ain shams university cairo 2015. Seismic inversion is now commonly used on poststack and prestack seismic data for estimating rock properties used in reservoir characterization. Nevertheless, in practice, applications of inversion methods can be grouped in two categories.
Full seismic waveform modelling and inversion springerlink. Machine learning meets seismic interpretation agile. However, both methods can be useful in the delineation of hydrocarbon reservoirs. Purchase global optimization methods in geophysical inversion, volume 4 1st edition. Inversion is defined as mapping the physical structure and properties of the subsurface of the earth using. As determination of lithology and fluid content distribution is a desirable objective for reservoir. The deterministic nature of linear inversion requires a functional relationship which models, in terms of the earth model parameters, the seismic variable to be inverted. The conclusion of these studies confirm that the seismic inversion is highly nonlinear when seismic traces are used as input data and the problem become very difficult to solve. Several of these methods were applied to a prospective.
This will involve looking at the basic concept of seismic reflectivity in its various forms, as well as inverted reflectivity, or impedance. This barcode number lets you verify that youre getting exactly the right version or edition of a book. We have developed a new stochastic nonlinear inversion method for seismic. Society of exploration geophysicists introduction to seismic inversion methods, brian h. In a seismic inversion the original reflectivity data, as typically recorded routinely, is converted from an interface property i. However, the two methods are related as the results of deterministic models is the average of all the possible nonunique solutions of stochastic methods.
They show the advantage of these methods, over more standard deterministic gradientdescent approaches, is in avoiding the need for a starting model and the calculation of gradients. Accurate wavelet estimation is critical to the success of any seismic inversion. We have also seen that these methods can be severely affected by noise, poor amplitude recovery, and the bandlimited nature of seismic data. The main objective of this method is to map the structures of subsurface formations in order to.
Basic principles of the seismic method in this chapter we introduce the basic notion of seismic waves. Students 2015 to geophysics department faculty of science ain shams university supervised by dr. Measurement of seismicwave travel time is one of the most common geophysical method. Transforming seismic reflection data into quantitative. An overview of avo and inversion brian russell, hampsonrussell, cggveritas company. The generalized linear inversion gli has been extensively used to solve avo inversion problems, i. Interwell seismic inversion and reservoir characterization. To determine elastic parameters, the reflectivity from avo effects must be inverted.
Azza mahmoud abd ellatif elrawy lecturer of geophysics geophysics department. Seismic inversion geoscienceworld books geoscienceworld. In one of the modeldriven methods we support, the simplicity term is implemented by limiting the solution space to that spanned by. Pdf seismic inversion methods and some of their constraints. Typically, a reflection coefficient series from a well within the boundaries of the seismic survey is used to estimate the wavelet phase and frequency. Quantifying shallow seismic anomalies, published in aapg explorer. Terminology for inversion varies, depending on the different contractors and service providers, emphasis on certain approaches, and the goals to be accomplished. Nevertheless, in practice, applications of inversion methods can be grouped in two categories data modeling and earth modeling. Prestack 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.
This book covers the basic theory and techniques used in seismic inversion. The objective of seismic inversion is to convert reflectivity data interface properties to layer properties. Seismic attribute analysis analysis of unconventional resource plays reservoir geology thickness and lateral extent mineralogy porosity and permeability geochemistry total organic content toc maturity and kerogen richness geomechanics acoustic impedance inversion youngs modulus poissons ratio. We reserve the term modelbased inversion for methods that attempt to achieve resolution within and beyond the seismic band by a stronger use of the a priori impedance logs in the model term of equation 1. It handles a large range of seismic data in dedicated workflows from data conditioning to quantitative property estimation. Cambridge university press, 511 pages, isbn 9780521199100. The old and the new in seismic inversion cseg recorder. We seem to be a bit hopeless at fullblown book revi. Building on the basic theory of linear inverse problems, the methodologies of seismic inversion are explained in detail, including rayimpedance inversion and. However, as was shown in section 3, one of the key problems in the recursive inversion of seismic data is the loss of the lowfrequency component. Thus, in this course we shall primarily restrict our discussion to those inversion methods which attempt to recover a broadband pseudoacoustic impedance log from a bandlimited seismic trace. International publishingcham matrix book series 2017 matrix annals. Stochastic and deterministic seismic inversion methods for thinbed resolution view the table of contents for this issue, or go to the journal homepage for more 2012 j.
Seismic inversion is an important step in the reservoir characterisation process which assists you in understanding the rock matrix properties and reservoir fluid types. For free space, the onedimensional wave equation is derived. The book covers ocean acoustic tomography, inverse methods, seismic numerical modeling, asymptotic theory of normal modes and surface waves, foundation of inverse theory, etc. Here are some of the papers that we have published on seismic inversion. All modern seismic inversion methods require seismic data and a wavelet estimated from. It relates the different models of seismic propagation, reflection, and imaging providing links to reflectivitybased imaging and to nonlinear seismic inversion.
Cgg geoconsulting has developed a 4d inversion workflow extending the 3d simultaneous elastic inversion to joint multivintage inversion, with simultaneous inversion of all angle stacks for base and monitor surveys. Jul 18, 2014 last year, i did a roundup of six books about seismic interpretation. Integration of seismic information in reservoir models. This functional relationship is some mathematical model derived from the fundamental laws of physics and is more often called a forward model. Described as the flipside of forward modeling, seismic inversion is the process of characterizing rocks and fluids that have produced the seismic data. Global optimization methods in geophysical inversion. There are numerous combinations, hybrids, and variations of these inversion methods. Johannes amtmann showed us how machine learning can be useful for ranking the performance of different clustering methods using forward models. Global optimization methods in geophysical inversion, volume. Recent progress in numerical methods and computer science allows us today to simulate the propagation of seismic waves through realistically heterogeneous earth models with unprecedented accuracy. Conventional practice was to delineate the reservoir using post stack seismic data while prestack seismic data was completely ignored. Buy introduction to seismic inversion methods course notes series, no.
Jun 20, 2017 machine learning isnt just useful for computing in the inverse direction such as with inversion, seismic interpretation, and so on. Geophysicists are now able to extract greater quantitative information about reservoir rocks and fluid parameters from seismic data by working backwards using seismic inversion methods. There is a bright future for the use of geophysics but it requires that inversion be applied with care and understanding. Seismic inversion is essentially a very simple procedure. Modelbased inversion produces a blocky output that contains more geological detail than bandlimited inversion. Anyone using inversion algorithms, or interpreting resultant images, must be familiar with the basic principles. Reservoir characterization using avo and seismic inversion techniques abhinav kumar dubey, iit kharagpur summary reservoir characterization is one of the most important components of seismic data interpretation. Sip provides simultaneous inversion from prestack depth migrated data for extra accuracy. New introduction to seismic method linkedin slideshare. Modelbased inversion introduction to seismic inversion. Since seismic linear inversion is a deterministic inversion method, the stochastic method.
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