While modern multichannel data have increased the quantity and quality of interpretable data, proper interpretation still requires that the interpreter draw upon his or her geological understanding to pick the most likely interpretation from the many. Depth conversion is an important step of the seismic reflection method, which converts the acoustic wave travel time to actual depth, based on the acoustic velocity of subsurface medium sediments, rocks, water. Muerdter is a geophysical consultant specializing in seismic modeling, illumination studies, and the conversion of seismic time to depth. A petroleum geologists guide to seismic reflection.
Join, renew or reinstate membership vote now election. In addition to the printed, hardcover version, avo also is available in pdf format on a usb. Advanced velocity modeling incorporate well log velocities, timedepth curves, event and fault interpretation, and seismic velocities into a consistent velocity model. The course focuses on intuitive quality controls and quantitative spreadsheet tools to plan and ensure stable depth solutions during the iterative imaging process. The basic issue in seismic reflection interpretation is the conversion of the measured two way time into depth. Seismic velocity estimation and timetodepth conversion. Exercises avo amplitude variation with offset interpretation exercise prestack time.
A good seismic image is not enough for an exploration or field development interpretation. Four case studies make up almost the entire last third. Timedomain seismic processing has been a popular and effective tool in areas with. Calculation of refractor depth from delay time if velocities of both layers are known, then refractor depth at point a can be. Seismic data interpretation and evaluation for hydrocarbon. Shale reservoir characterization is also the focus of 3d seismic interpretation. Tandon summary a seismic velocity model is necessary to map depth and thickness of subsurface layers interpreted from seismic reflection images. Focusing on the everyday problems facing the working interpreter, this book has a geological emphasis and is aimed especially to those. The importance of timetodepth conversion would be evident in the look of consternation on a. The interpreters guide to depth imaging by scott mackay.
Interpretation of any data, especially seismic data in petroleum exploration. Time to depth conversion and uncertainty characterization. Principles of seismic velocities and timetodepth conversion m. As a result the extent of application of computer migration schemes remains unclear. To perform the depth conversion, the velocity of the medium situated above the. Despite its fundamental importance for acquiring an accurate picture of the subsurface, the topic of timetodepth conversion on the basis of true propagation velocities has never been addressed in the form of a comprehensive, dedicated book. Acoustic logs, checkshot surveys and vertical seismic profiles can aid depth conversion efforts and improve correlation of well logs and drilling data with surface seismic data. Here we will go through a time to depth conversion of a 2d seismic survey in the sichuan basin using a velocity model provided in depth. He is president of luminterra llc in seattle, washington. Pdf geostatistical techniques were used for seismic timedepth conversion over labod field offshore western niger delta basin with the aid. Graham and trotman seismic reflection interpretation has been well served with texts in recent years, but this book is notable in presenting plenty of casehistory material. Geo expro a simple guide to seismic depth conversion i. Seismic velocity estimation and time to depth conversion of timemigrated images maria cameron.
The present book has long been overdue for bridging this obvious gap in geoscience. Pdf analysis of seismic timedepth conversion using. The interpreter identifies the time horizons that are associated with depositional sequence boundaries and geologically and lithologically significant layer boundaries within some of the depositional units. Depth conversionsimple average velocity convert depth to depth below seismic reference datum, and convert twt to a oneway time. We understand thus that it is convenient to carry out the impedance inversion in depth directly, and we can take advantage of the superior imaging of the re. Although most geophysical interpretation is performed in time domain, geological. This book is published in under open access creative commons license ccbyncnd. The course focuses on intuitive quality controls and quantitative spreadsheet tools to plan and ensure stable depth solutions during the. Softwares interpretative analyses of cdp gathers, nmo stack, fk filtering deconvolution and migration. This chapter of seismic data analysis techniques in hydrocarbon exploration explains seismic interpretation methodology in details. Seismic velocity estimation and timetodepth conversion of.
Timetodepth conversion and seismic velocity estimation using. Despite its fundamental importance for acquiring an accurate picture of the subsurface, the topic of time to depth conversion on the basis of true propagation velocities has never been addressed in the form of a comprehensive, dedicated book. These result in depth variation right which increases away from the wells. The authors have found that geologists and geophysicists tend to approach the depth conversion process quite differently. The statistical approach for depth conversion not only demonstrates that the reservoir depth can be predicted with high accuracy but also that reliable uncertainty estimations can be provided. Depth migrated data is often converted back to time and then depth converted conventionally as this gives greater flexibility for testing alternative velocity models. Simply defined, seismic interpretation is the science and art of inferring the geology at some depth from the processed seismic record. An introduction to seismic interpretation pdf free download. The process of transforming seismic data from a scale of time the domain in which they are acquired to a scale of depth to provide a picture of the structure of the subsurface independent of velocity. Seismic interpretation and depth conversion of the. Depth conversion concerns the seismic interpreter because seismic measurements are made in time, but the wells based on a seismic interpretation are drilled in depth. Introduction gocad offers conversion of horizons and seismic in the time domain to the depth domain and vice versa. Seismic velocity estimation and time to depth conversion of timemigrated images.
Seismic interpretation better tools, better understanding, in less time. Principles of seismic velocities and timetodepth conversion eage. Rifted fault blocks significance of time maps depth conversion exercise. Although the two way time twt is known measured, still there are two unknown parameters. Depth conversion domain conversion of seismic time interpretations and data is a basic skill set for interpreters. Timetodepth conversion and seismic velocity estimation using time. Standard inputs for depth conversion, such as time interpretation, well, and seismic velocities, can produce a wide range of depth structures. Approximating a seismic horizon timedepth conversion using a. In this video you will learn the different methods for depth conversion. A robust approach to timetodepth conversion and interval velocity estimation from time.
The topic of migration is similarly split, for it appears mostly in the dataprocessing chapter while depth conversion is limited to a short paragraph in the chapter on geophysical interpretation. Time to depth conversion and uncertainty characterization for. Principles of seismic velocities and time to depth conversion m. Construction and interpretation of structural map using. During migration or timetodepth conversion, adjacent seismic data samples might be processed with radically. Thickness, fracture permeability, brittleness, organic richness, pore pressure, and more can be determined from seismic data chopra et al. Part ii seismic input to reservoir characterization. Seismic data onshoreoffshore 2d and 3d interpretation parameters seismic data libraries. Figure 15 summary of acquisition and processing of seismic reflection. A velocity model is required in the form of a voxet. Timetodepth conversion and seismic velocity estimation using timemigration velocitya apublished in geophysics, 73, no. Geostatistical techniques were used for seismic timedepth conversion over labod field offshore western niger delta basin with the aid of surface seismic and. Depth conversion and sensitivities depth accuracy can be influenced by something as simple as the function used to calibrate seismic velocities to wells. A robust approach to timetodepth conversion and interval velocity.
Pdf summary we address the problem of time to depth conversion of time. A timetodepth velocity conversion can be done by first applying the dix inversion. Depth conversion, ideally, is an iterative process that begins with proper seismic processing, seismic velocity analysis and study of well data to refine the conversion. Time to depth conversion free download as powerpoint presentation. This publication is the definitive, and now classic, text on the subject of interpretation of 3d seismic data. Time to depth conversion and seismic velocity estimation using time migration velocitya apublished in geophysics, 73, no. In large part, this book is a compilation of notes from seismic inter pretation.
Seismic velocity estimation and time to depth conversion of timemigrated images article pdf available in seg technical program expanded abstracts 251 january 2006 with 274 reads. Jul 19, 2016 by joanne wang one of the major challenges in seismic interpretation is seismic towell tie in the depth domain. Seismic velocity estimation and time to depth conversion of time migrated images maria cameron. Pandey, ravendra kumar, manish shukla, anil negi, a. However, timetodepth conversion is certainly as important in obtaining the end product. Pdf seismic velocity estimation and time to depth conversion of. Home principles of seismic velocities and time to depth conversion. Depth conversion is an important step of the seismic reflection method, which converts the acoustic wave travel time to actual depth, based on the acoustic velocity of subsurface medium sediments, rocks, water depth conversion integrates several sources of information about the subsurface velocity to derive a threedimensional velocity model. Approximating a seismic horizon time depth conversion using a twovelocity layer approach in seisworks frequently in industry you will want to display a horizon map in depth ft instead of the landmark seisworks default, which is twoway time twt. A complete description of geology requires that any interpretation derived from these data, recorded in the time domain, be placed accurately in the 3d depth domain, and you use velocity information to accomplish this transformation from time to depth. Introduction to seismic interpretation linkedin slideshare. Despite the obvious drawback of this top down strategy, i. However, time to depth conversion is certainly as important in obtaining the end product.
Seismic map present the shape and form of geological formation top or bottom. A robust approach to timetodepth conversion and interval. The book is written for the interpretation geophysicist working in exploration and development, for the seismic. The measured time is known as the two way time twt. Depth conversion and seismic lithology inversion of a. Seismic data analysis techniques in hydrocarbon exploration. In the recent past, most effort has been directed towards improving the quality of the seismic time definition of the subsurface. The depth conversion can now be carried out as part of the data processing, but this depth imaging is only done in special circumstances. A robust approach to time to depth conversion and interval velocity estimation from time migration in the presence of lateral velocity variationsa apublished in geophysical prospecting, 63, no. Key interpretation skills covered are well log correlation, synthetic seismogram generation, welltoseismic tie, timetodepth conversion, fault interpretation, seismic horizon interpretation and mapping.
Principles of seismic velocities and time to depth conversion. Timetodepth conversion is performed iteratively layer after layer. Good well ties and reliable depth conversion are also required. This paper discusses two aspects of the seismic based subsurface interpretation.
Alchalabi and a great selection of similar new, used and collectible books available now at great prices. An aid for better understanding of subsurface a case study from cambay basin, india ajeet kr. Moveout click on an image for a highresolution adobe acrobat pdf version of the figure. Here we will go through a time to depth conversion of a 2d seismic survey in the sichuan basin using a. Converts seismic and attributes data between time and depth option to scales in same domain can use maps, fm. By joanne wang one of the major challenges in seismic interpretation is seismictowell tie in the depth domain. Timetodepth conversion and seismic velocity estimation. Seismic velocities and depth conversion svdc petroskills. Depth conversion and seismic lithology sandshale characterization. Timetodepth conversion and seismic velocity estimation using timemigration velocitya. Time to depth conversion and uncertainty characterization for sagd base of pay in the mcmurray formation, alberta.
With the data acquired, showing the seismic reflection times was converted from a time data to a depth data using time to depth conversion chat. Kingdom seismic and geological interpretation software. Approximating a seismic horizon timedepth conversion using a twovelocity layer approach in seisworks frequently in industry you will want to display a horizon map in depth ft instead of the landmark seisworks default, which is twoway time twt. Timetodepth conversion and seismic velocity estimation using timemigration velocity article pdf available in geophysics 735 september 2008 with 1,225 reads how we measure reads. Then, reflection times are picked by combining seed detection and linebased interpretation strategies interpretation of 3d seismic data. Geophysicists proficient in data processing fully appreciate that depth. Seismic interpretation an overview sciencedirect topics. The emerson seismic interpretation suite is an integrated, modern interpretation and visualization system designed to carry out all seismic interpretation tasks, including structural, stratigraphic, and volume interpretation.
Objectives understand importance of timedepth conversion in the exploration process and the importance of interpretation in depth vs. W7 well logs and synthetic seismograms, seismic well calibration 10. High resolution seismic reflection practical basis wgeosoft. Travel time curves analysis of seismic refraction data is primarily based on interpretation of. Depth conversion integrates several sources of information about the subsurface velocity to derive a threedimensional velocity model. Principles of seismic velocities and timetodepth conversion. Principles of seismic velocities and timetodepth conversion 9789073834873 by m. To convert from time s to depth ft you must know the velocity of the material. The purpose of depth conversion is to filter out erroneous input data whilst understanding the impact of remaining data. Depth conversion domain conversion of seismic time interpretations and data is a.
Dynamic depth conversion and map update dynamically build velocity models by tying your well and seismic data. Timetodepth conversion and seismic velocity estimation using timemigration velocity maria cameron1, sergey fomel2, and james sethian3 abstract the objective was to build an ef. The results that are being demonstrated for impedance inversion in depth. Conceived in 1979 and first published in 1986, the book helps geoscientists extract more information from their seismic data and improve the quality of their interpretations. Feb 15, 2017 in this video you will learn the different methods for depth conversion. Time to depth conversion and seismic velocity estimation using timemigration velocity. A presentation prepared for new afpc staff introduction. For any horizon we have a range of calibration functions left.