The authors provide an integrated methodology and practical tools for quantitative interpretation, uncertainty assessment, and characterization of subsurface reservoirs using well-log and seismic data. True amplitude migration Principle of true-amplitude migration Generation of angle gathers 6. Using a Bayesian classification scheme the probability of that sample being any one of the possible lithology and fluid combinations can be calculated. It removes the effects of the wavelet within the seismic bandwidth. Curvature: This is a group of post-stack attributes that are computed from the curvature of a specified horizon. Quantitative Seismic Interpretation demonstrates how rock physics can be applied to predict reservoir parameters, such as lithologies and pore fluids, from seismically derived attributes.
Both windows provide attractive functionalities for this, including a comprehensive set of dedicated algorithms for pre-conditioning the data, an interactive framework for running the process, and an advanced platform for visualizing and analyzing the results. Paradigm believes its forthcoming Epic software is an approach that can help solve this market need. Left one shows the seismic response of lateral variations in the thickness of individual sedimentary layers. For the complicated structures, forward modeling of seismic data helps us to develop advanced techniques of imaging. This failure is because of lack of consideration of wavelet phase. Benefits of Seismic Inversion The concept of impedance and geology is better understood by most geologists than the seismic trace. Ellipses are shown at 100m depth increments.
The geometry on the seismic section is precisely interpreted in view of the geological concepts to detect the hydrocarbon accumulation. Then moving left to right in below diagram changes in Reflectivity at horizon boundaries results in normal incident reflection coefficients. Understanding pore pressure is important in deep prospects. Increasingly over the last decade, rock physics has become an integral part of quantitative seismic interpretation and stands out as a key technology in petroleum geophysics. Traditionally, reflection seismic is used for its kinematic attributes, i.
Recovery of this resource is challenging and there are e safety concerns regarding environmental in it. Seismic-to-well matching Model based wavelet estimation Filter design to match different datasets Reflectivity estimation from well data Seismic-to-well matching methods Least-squares wavelet estimation with well data 10. Main types of unconventional gas reservoirs: Tight gas — Very refined techniques are required to reduce the migration distances from the formation to the well. The inferred shape of the seismic wavelet may strongly affect the seismic inversion results and also the assessments of the reservoir quality. The synthetic seismic records can be used to assess whether an expected geologic target will generate an interpretable signature on output processed data or not. The purple polygon captures the bounding lithology. They first discuss how to process the repeated 3D seismic surveys in order to preserve production related amplitude and time changes and remove non-production effects.
Our ability to identify a source rock in the subsurface and quantify its parameters has a significant impact on prospect risking and petroleum play analyses. With the help of this, one can measure reflectivity in order to map direct hydrocarbon indicators in a zone of interest. This book is aimed at graduate students, academics and industry professionals working in the areas of petroleum geoscience and exploration seismology. Leads to improved Stratigraphic interpretation. Professor Mukerji is also a co-author of The Rock Physics Handbook Cambridge University Press, second edition 2009 , and has taught numerous industry courses.
Seismic inversion may be pre-stack or post-stack, deterministic or geostatistical, and typically includes other reservoir measurements such as well logs and cores. The Structural and stratigraphic architecture of the petroleum system is determined and on behalf of these geometric features the location of the well is established. Per worked at Norsk Hydro Research Center in Bergen from 2001, and at Rock Physics Technology from 2006. Amplitude Attributes: They use the seismic signal amplitude as the basis for their computation. Take the well impedance data and band pass it to the same frequencies as the seismic data.
Chief among these is the ever present difficulty of data management. A seismic attribute that can indicate the presence or absence of hydrocarbons is known as a direct hydrocarbon indicator. Acoustic impedance obtained from seismic inversion can also be considered an attribute and was amongst the initially developed. So, to resolve this difficulty we use various unconventional seismic interpretation techniques as discussed below. In the quantitative interpretation workflow, the interpreter attempts to characterize the rock type, fluid composition, and flow characteristics of the reservoir. In their textbook, Avseth et al. The reflection coefficient is replaced by a wavelet is centered and weighted by the reflection coefficient.
My expectation is that this area of seismic interpretation will continue to grow and that it is important for geoscientists to have a good grasp of these techniques. They then perform fluid replacement analysis to predict the expected production changes. Often, different parts of the quantitative analysis workflow are conducted in disparate, disconnected tools. It gives an overview of the factors that affect seismic amplitudes and of proper ways to process the seismic data such that amplitude information is preserved, which is then followed by the extraction of the relevant attributes and their interpretation. Because of its efficiency and quality, most oil and gas companies now use seismic inversion to increase the resolution and reliability of the data and to improve estimation of rock properties including porosity and net pay. Maximum Magnitude: A post-stack attribute that computes the highest value of the absolute value of the amplitudes within a window. The blue polygon captures the down-dip part of this anomaly.
It can be mapped for Cylindrical Coordinates, Cartesian Coordinates, and also the Spherical Coordinates. Accurate wavelet estimation is very important for the success of any seismic inversion. The user reviews and conditions the data in Paradigm's 2D Canvas for detailed work, or 3D Canvas for more integrated interpretation. This method can model almost all kinds of waves propagating in elastic or inelastic media with high numerical stability and accuracy but relatively less computation cost. Petrel Quantitative Interpretation enables true integration of multidisciplinary seismic with well and geological data.