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EAGE/SEG Research Workshop - Multicomponent Seismic - Past, Present and Future
- Conference date: 05 Sep 2005 - 08 Sep 2005
- Location: Pau, France
- Published: 05 September 2005
53 results
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Suppression of Free-Surface Effects from Multicomponent Sea-Floor Data
More LessA01 SUPPRESSION OF FREE-SURFACE EFFECTS FROM MULTICOMPONENT SEA-FLOOR DATA 1 Summary. We use multicomponent sea-floor data to suppress receiver-side ghosts and free-surface multiples and to datum the results of ghosts and multiple suppression from the sea-floor to the free-surface. Both steps – deghosting and multiple suppression - are applied trace by trace to the tau-p transformed common receiver gathers. 2D datuming for structures with inline lateral variations is performed in the same tau-p domain. Therefore effective suppression of aliasing in the tau-p transform is of crucial importance. In addition to the dip filter our antialiasing protection is based on simple
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Converted-Wave Imaging in Anisotropic Media – Part I – Theory and Methods
Authors X.-Y. Li, H. Dai and F. ManciniA02 CONVERTED-WAVE IMAGING IN ANISOTROPIC MEDIA – PART I: THEORY AND METHODS XIANG-YANG LI 1 HENGCHANG DAI 1 FABIO MANCINI 2 Abstract 1 We review and present the recent developments in converted-wave (C-wave) processing for vertical transverse isotropy (VTI) in two parts. Part I covers the basic theory and methods addressing issues such as how many parameters are required to perform C-wave anisotropic prestack time migration and how to estimate these parameters followed by a 2D data example for illustrating purposes. Part II discusses the extension to 3D. The converted-wave kinematic response in inhomogeneous VTI media is separated into two
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Converted-Wave Imaging in Anisotropic Media – Part II – 3D Application and Case Study from the North Sea
More LessA03 CONVERTED-WAVE IMAGING IN ANISOTROPIC MEDIA - PART II: 3D APPLICATION AND CASE STUDY FROM THE NORTH SEA Abstract 1 HENGCHANG DAI* 1 XIANG-YANG LI 1 AND PAUL CONWAY 2 1 British Geological Survey 2 Kerr-McGee North Sea (UK) Ltd We present a practical approach to extend the theory and method of converted wave image to 3D dataset by performing the 3D pre-stack Kirchhoff time migration in a PC cluster and to build the migration velocity model. This approach is successfully applied to a 3D-4C OBC dataset acquired in the North Sea to use its PS-waves to image the structure
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Shear Wave Depth Velocity Model Building by PS Stereotomography
Authors G. Lambaré, J.-L. Boelle, K. Meier and D. Della MorettaA04 SHEAR WAVE DEPTH VELOCITY MODEL BUILDING BY PS STEREOTOMOGRAPHY Abstract 1 PS Stereotomography was proposed for VS velocity model building from multi-component seismic datasets. No pairing of PP and PS events is a priori required leading to a very practical solution for building the VS velocity model building. After several applications on real and synthetic datasets a semi-automatic strategy has now emerged for PP-PS Stereotomography. We present here a state of the art and a perspective view for PS Stereotomography from OBC data based on synthetic and real data applications. Introduction Stereotomography is a method for estimating velocity macro
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Problems and Solutions for Elastic Migration in the Angle-Azimut Domain
Authors L. Nicoletis, P. Froidevaux and O. BouhdicheA05 PROBLEMS AND SOLUTIONS FOR ELASTIC MIGRATION IN THE ANGLE-AZIMUT DOMAIN Introduction 1 The classic approach for true amplitude migration in the offset domain uses the Beylkin determinant (Beylkin 1985) which is the Jacobian of the change of coordinates from the surface acquisition (CMP coordinates) to the illuminations vector at the depth point. The Beylkin Jacobian handles the irregularity of illumination due to the propagation in the subsurface assuming a reasonably regular acquisition. The Beylkin determinant was extended to migration in the scattering angle domain for marine type survey by Xu et al. (1998) and results in a rather complex
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A Review of 3D Vectorial True Amplitude Prestack Migration of Converted S-Waves
Authors L. Nicoletis, J. Svay-Lucas and P. FroidevauxA06 A REVIEW OF 3D VECTORIAL TRUE AMPLITUDE PRESTACK MIGRATION OF CONVERTED S-WAVES Introduction 1 Processing of converted modes requires specific algorithms that take count of their particular kinematics. Recently a great attention has been paid to prestack isotropic and anisotropic time migration approaches. However the applicability of time domain processing to C-wave is much more restricted than it is for P-wave since any lateral velocity variations impacts the conversion point location. Hence there is a great need for C-wave dedicated depth imaging workflow. In this paper we develop some key aspects related to the imaging of 3C converted waves
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True Amplitude Weights for Converted Wave Kirchhoff Migration
Authors X. Miao, S. Gray, Y. Zhang and R. KendallA07 TRUE AMPLITUDE WEIGHTS FOR CONVERTED WAVE KIRCHHOFF MIGRATION Abstract 1 We derive common offset true amplitude weight functions in a v(z) medium for 2.5D and 3D converted-wave Kirchhoff migration. The weight formulas are then simplified into terms involving travel time ray path and velocity functions for efficient computation. The simplified weight functions are also examined with numerical model data for depth migration which demonstrates well controlled amplitude behavior in offset and depth. Introduction Preserving amplitudes in converted-wave prestack migration is important for subsequent AVO processing and interpretation. However it has not received as much attention as amplitude preservation for
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Wave-Equation Angle-Domain Imaging for Multicomponent Seismic Data
More LessA08 WAVE-EQUATION ANGLE-DOMAIN IMAGING FOR MULTICOMPONENT SEISMIC DATA 1. Abstract Seismic images obtained by multicomponent wave-equation migration can be decomposed into angle gathers with a transformation that generalizes the equivalent construction for primary waves. A particularly simple formulation is to use all three components of the offset vector separating sources and receivers at image points. Using full vector offsets multicomponent angle-gathers are built using simple transformations that are implemented partially in the Fourier domain and partially in the space domain. 1 2. Introduction Downward wave extrapolation provides an accurate method for seismic imaging in structurally complex areas (Gray et al.
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Reservoir Delineation Using Joint Prestack Inversion of Multicomponent Seismic Data
By H. ÖzdemirA09 RESERVOIR DELINEATION USING JOINT PRESTACK INVERSION OF MULTICOMPONENT SEISMIC DATA 1 Introduction Lithological and pore fluid properties can be inverted from prestack seismic data for reservoir characterization with the use of amplitude versus offset (AVO) analysis. When the P-wave contrast is small or gas clouds obscure reservoir layers multicomponent sea bottom recording of converted waves (Ps) is used to map reservoir zones. Angle band stacks of multicomponent P-wave (Pz) and Ps data inverted jointly provide absolute acoustic impedance (AI) S impedance (SI) and density. These computations can be used to map reservoir parameters through all stages of field development
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Simultaneous Inversion of PP and PS Seismic Data – A Case History from Western Canada
Authors K. Hirsche, D. Hampson, J. Peron and B. RussellA10 SIMULTANEOUS INVERSION OF PP AND PS SEISMIC DATA – A CASE HISTORY FROM WESTERN CANADA Summary: 1 K. HIRSCHE D. HAMPSON J. PERON AND B. RUSSELL Hampson Russell Software 510 715 – 5 Ave SW Calgary Alta. Canada T2P-2X6 We have recently developed a new method for simultaneously inverting P-wave and converted wave (PS) seismic volumes. This new inversion approach accounts for the physical relationship that exists between P-wave and S-wave velocities and it provides a significant improvement over independent inversions of the two datasets; particularly for Vp/Vs ratio estimates. We applied this new inversion technique to a 3D
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A Proposed Workflow for Heavy Oil Reservoir Characterization Using Multicompnent Seismic Data
Authors R.R. Kendall, P.F. Anderson, L. Chabot and F.D. Gray1 A11 A PROPOSED WORKFLOW FOR HEAVY OIL RESERVOIR CHARACTERIZATION USING MULTICOMPONENT SEISMIC DATA R. KENDALL* P. F. ANDERSON L. CHABOT F. D. GRAY EAGE/SEG Research Workshop – Pau France 5 – 8 September 2005 Veritas Suite 2200 715 – 5 th Avenue SW Calgary Alberta Canada T2P 5A2 Summary Over the past few years multicomponent data have been used increasingly in the development of heavy oil projects either for improved noise attenuation methods (Kendall 2005) or for the additional information that the multicomponent seismic provides the interpreter. One of the challenges with multicomponent seismic data is understanding and managing
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Evolution of a Multicomponent Autonomous OBS – The Role of Geophysics
Authors J. Paffenholz, R. Shurtleff, D. Hays and P. DochertyA12 EVOLUTION OF A MULTICOMPONENT AUTONOMOUS OBS: THE ROLE OF GEOPHYSICS Abstract 1 Multi-component ocean bottom seismic (OBS) data for oil and gas exploration have traditionally been acquired with systems in which many seismometers are physically linked with a cable. An alternative approach is to record data utilizing a set of distributed nodes each operating autonomously. The high degree of flexibility in the receiver geometry permitted by a node based system is a motivating factor for employing nodes for some geophysical objectives such as wide azimuth imaging. Our development of such a system through several iterations has provided insight into
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A Deep Water 4C 4D Permanent Installation Pilot
Authors C. Massacand, M.C. Hodge, H. Teigland and M. MillingtonA13 A DEEP WATER 4C 4D PERMANENT INSTALLATION PILOT Abstract 1 M.C. HODGE C. MASSACAND H. TEIGLAND M. MILLINGTON Multiwave Geophysical Company ASA Damsgårdsveien 125 N-5162 Bergen Norway This presentation outlines some of the challenges faced with the installation of a buried 4C-4D seismic cable over a deep-water oil-producing field in the Gulf of Mexico. A single 6km 4C cable was laid on the seafloor and tied back to recording equipment on the platform. The MARS field utilizes a “Tethered Leg Platform” design because of its location in over 1000 metres of water. The 4C installation design had to take
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Trials of Autonomous 4C Nodes in Deep Waters
Authors P.Y. Granger, M. Manin, A. Rollet, J.-L. Boelle, E. Ceragioli, F. Lefeuvre and E. CrouzyA14 TRIALS OF AUTONOMOUS 4C NODES IN DEEP WATERS. Pierre-Yves Granger(1) Michel Manin(1) Anne Rollet(1) Jean-Luc Boelle(2) Enrico Ceragioli(2) Frédéric Lefeuvre(2) and Emmanuel Crouzy(3) Abstract 1 During the summer of 2004 an experimental OBS survey was acquired and processed by CGG over the Girassol field operated by Total Angola offshore West Africa. Five ARMSS (Autonomous Reservoir Monitoring Seismic System) nodes were deployed in this area at a water depth of 1300 meters. The primary objective of this trial was to verify the operational sequence and performance of this new generation of 4C recording equipment. There were also a number of
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Effects of an Anelastic Seafloor on the Elastic Decomposition of Marine Multi-Component Seismic Data
Authors K. Eggenberger, R. Muijs, J.O.A. Robertsson, D.-J. Van Manen and K. HolligerA15 EFFECTS OF AN ANELASTIC SEAFLOOR ON THE ELASTIC DECOMPOSITION OF MARINE MULTI-COMPONENT SEISMIC DATA Abstract 1 Dual-sensor (hydrophone and three-component geophone) data recorded on the seafloor allow for the decomposition of the seismic wavefield into its up- and down-going P- and S-wave constituents. Elastic wavefield decomposition requires accurate knowledge of the seismic material properties of the seafloor in the immediate vicinity of the receivers and is based on the assumption that the seafloor can be represented as an elastic half-space. For most recording environments this assumption is clearly not valid. To explore the potential implications we apply a state-of-the-art
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Data-Driven P-S Separation in OBC Data
Authors P. Edme, M.T.A. Soudani, J.L. Boelle and S.C. SinghA16 DATA-DRIVEN P-S SEPARATION IN OBC DATA EDME P. 1 SOUDANI M.T.A. 2 3 BOELLE J.L. 2 SINGH S.C 1 . Abstract 1 OBC technology provides information on both pressure and particle velocity recorded at the seafloor level allowing complementary PP and PS imaging. In the following paper we describe a new elastic decomposition scheme that separates upgoing-downgoing P and S wavefields in the��-p domain. We introduce frequency dependant operators to calibrate the geophones so that the process does not require any a priori knowledge of seafloor parameters. We start by describing theoretical aspects for complete decomposition. Then we detail
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Experiences Processing Two Similar but Different Land 3D-3C MEMS Surveys
More LessA17 EXPERIENCES PROCESSING TWO SIMILAR BUT DIFFERENT LAND 3D-3C MEMS SURVEYS Abstract 1 Historically land multicomponent (MC) surveys results have been mixed resulting in an industry perception that embarking on MC projects is a risky and expensive endeavor. Although geology has often played a role sub-optimal equipment acquisition design and processing have also contributed to this perception. The advent of high vector fidelity 3-component MEMS-based land acquisition systems has sparked renewed interest in learning how to utilize the recorded vector wave field not only for converted-wave (C-wave) imaging but also for improved P-wave imaging. In this article we review our
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An SVD-Polarization Filter for Ground Roll Attenuation on Multicomponent Data
Authors R. Kendall, S. Jin, S. Ronen and K. De Meersman1 A18 AN SVD-POLARIZATION FILTER FOR GROUND ROLL ATTENUATION ON MULTICOMPONENT DATA R. KENDALL 1 S. JIM 1 S. RONEN 1 K. DE MEERSMAN 2 1 Veritas Suite 2200 715 – 5 th Avenue SW Calgary Alberta Canada T2P 5A2 2 School of Earth and Environment University of Leeds Leeds LS2 9JT UK Summary By their very nature multicomponent data provide information on the full wavefield and therefore offer new full-wavefield solutions for the ground roll problem. Here we introduce a time domain multicomponent Singular Value Decomposition (SVD) polarization filter that is optimized to remove most ground roll energy while
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Analysis of P-Wave and Converted-Wave Seismic Data, Anadarko Basin, Oklahoma, USA
Authors S. Roche, M. Wagaman and H. WattA19 ANALYSIS OF P-WAVE AND CONVERTED- WAVE SEISMIC DATA ANADARKO BASIN OKLAHOMA USA. S. ROCHE M. WAGAMAN H. WATT Abstract 1 Veritas DGC Multicomponent Applications Group 10300 Town Park Drive Houston Texas 77072 USA Multicomponent 3-D seismic data were acquired in the Anadarko Basin USA. The multicomponent recording spread used a single 3C digital sensor per station embedded in a conventional 3-D 1C survey. Converted-wave (PS) data were recorded from reflectors exceeding 14000 ft in depth. The conventional P-wave structural image is similar to the PS image but differing reflectivity indicates there is additional information to be extracted from the
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Delineating a Sand Reservoir Using 3C-3D Seismic Data, Horizontal Well Logs, and VSP
Authors R.R. Stewart and C. XuA20 DELINEATING A SAND RESERVOIR USING 3C- 3D SEISMIC DATA HORIZONTAL WELL LOGS AND VSP Abstract This paper uses 3C-3D seismic data horizontal and vertical well logs and VSP to delineate a sandstone reservoir. The 3C-3D surface seismic data was acquired over Husky Energy’s Ross Lake oilfield in south-western Saskatchewan. In previous work a Vp/Vs map between two marker horizons (the IHACM and RushLake) was calculated by combining PP and PS travel time thickness maps. In this paper the impedance inversions are performed on the poststack PP and PS data. By dividing the average of the inverted P-impedance over a
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Forseti - "Stealth" Imaging with 4C OBC Seismic
Authors T.D. Rape, A. Shatilo, X.G. Li, S. Oppert, K. Lewallen, D. Coney and K. EspejordA21 FORSETI - "STEALTH" IMAGING WITH 4C OBC SEISMIC Summary: 1 T.D. RAPE 1 A. SHATILO 1 X.G. LI 1 4 S. OPPERT 2 K. LEWALLEN 2 D. CONEY 3 K. ESPEJORD 3 1 ExxonMobil Upstream Research Co. PO Box 2189 Houston TX USA 77252-2189 2 ExxonMobil Exploration Co. 3 Esso Norge AS 4 currently IntSeis Inc. An ever-challenging goal of this industry is to extract as much useful information as possible from seismic data. Multicomponent seismic data present the opportunity to extract more information but of course it is more challenging to do so. There are many different applications
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Time Lapse Seismic Analysis Using Long Offset PS Data
Authors H. Mehdizadeh, M. Landrø, B.A. Mythen, N. Vedanti and R. SrivastavaA22 TIME LAPSE SEISMIC ANALYSIS USING LONG OFFSET PS DATA Abstract 1 A new time lapse seismic analysis method that exploits the high angle properties of PS reflected data is proposed. Many hydrocarbon fields are characterized by a significant increase in shear wave velocity at the top reservoir interface. If this increase is followed by a slight increase in P-wave velocity a well defined peak will occur for the PS reflection coefficient at high incidence angles. If the P-wave velocity within the reservoir layer changes due to production this will lead to a shift (with angle or offset) of this
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Multi-Component Seismic in Rough Terrain – An Example from Wyoming Green River Basin
Authors S. Ronen, C. Ansorger, M. Wagaman and M.L. JohnsonA23 MULTI-COMPONENT SEISMIC IN ROUGH TERRAIN: AN EXAMPLE FROM WYOMING GREEN RIVER BASIN Abstract 1 S. RONEN 1 C. ANSORGER 2 M. WAGAMAN 3 and M. L. JOHNSON 4 1 Veritas DGC Inc. 10300 Town Park Dr Houston TX 77072 USA EAGE/SEG Research Workshop – Pau France 5 – 8 September 2005 2 Veritas GeoServices 3 Veritas Land Surveys 4 ExxonMobil Upstream Research Company Test results indicate that single sensor three-component receivers provide better data than conventional groups of geophones in rough terrain. The images from the 3C data have better resolution and better imaging of dipping reflectors. Arguably the
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How Can We Unlock the Full Potential of Converted Wave Imaging?
Authors J.H. Kommedal and O.I. BarkvedA24 HOW CAN WE UNLOCK THE FULL POTENTIAL OF CONVERTED WAVE IMAGING? Introduction 1 JAN H. KOMMEDAL AND OLAV I. BARKVED BP Norge AS Godesetdalen 8 Stavanger Norway The introduction of high quality ocean bottom seismic equipment over the last decade has partly been driven by the need for C-wave imaging. However while a lot of progress has been made in improving OBS acquisition technology increasing numbers of receivers available for deployment and improving fidelity of the sensors there is a feeling that the quality of C-wave processing is still lagging behind. A possible reason for this may be lack
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3D High-Resolution Vp/Vs Inversion – Experiences from Recent Case Studies
Authors M. Nickel and L. SønnelandA25 3D HIGH-RESOLUTION VP/VS INVERSION: EXPERIENCES FROM RECENT CASE STUDIES Abstract 1 Recently we introduced a new scheme for 3D high-resolution vp/vs estimation by automating the PP PS event correlation process[1]. The scheme allows transferring the PS cube to the PP domain and thus enables a joint analysis of the data sets. Since event correlation is automated here the turn around time is significantly reduced and simultaneously precision is gained compared to the traditional horizon based manual approach. Furthermore the high-resolution vp/vs often lends itself as a lithology indicator. We will review the algorithm with respect to its robustness generality
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Benefits of 3D4C Surveys in the Caspian Sea
Authors R. Johnston, J. Bouska, T. Lyon and D. ManleyA26 BENEFITS OF 3D4C SURVEYS IN THE CASPIAN SEA Abstract 1 The first 3D ocean-bottom seismic (OBS) surveys in the Caspian Sea provide a new look at a complex geological region in terms of both P-wave and C-wave imaging. Novel acquisition design and a processing campaign spanning two years result in wide-azimuth P-wave images far superior to conventional narrow-azimuth towed streamer data. Wide-azimuth C-wave data provide a more reliable structural picture in places where distributed gas strongly affects the P-wave image. Wherever possible the processing has been designed to take advantage of the ocean-bottom setting and the acquisition design. Further
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Processing “Deep Water” 3D OBC Seismic Data at the Heidrun Field
Authors C. Hartline, D. Whitmore and S. ChiuA27 PROCESSING “DEEP WATER” 3D OBC SEISMIC DATA AT THE HEIDRUN FIELD 1 C. HARTLINE 1 D. WHITMORE 2 AND S. CHIU 2 1 currently ConocoPhillips P.O. Box 220 N-4098 Tanager Norway Summary In June 2003 the Heidrun Field partners completed acquisition of a 3D4C seismic survey in an attempt to provide better resolution of the field’s complex northern flank. The final PZ Kirchhoff pre-stack time migration was determined to be of lower quality than the 1986 3D streamer survey (reprocessed in 2001). The ConocoPhillips Subsurface Imaging and Prediction Group in Houston was requested by ConocoPhillips Norway to complete a
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Improved Sihil Image from 4C Full Azimuth Node Data
Authors E.W. Berg, M.V. Garcia, F. Maya, C.F.R. Torres, C. Vuillermoz and A. FyhnA28 IMPROVED SIHIL IMAGE FROM 4C FULL AZIMUTH NODE DATA 1 MARCO VÁZQUEZ GARCIA¹ FRANCISCO MAYA² CARLOS FEDERICO RUIZ TORRES² EIVIND W. BERG³ CLAUDE VUILLERMOZ³ & ATLE FYHN³ ¹Pemex CNPS Villahermosa ²Pemex Exploración y Producción Región Marina Noreste Ciudad del Carmen Mexico ³SeaBed Geophysical Trondheim Norway Summary A large 4C OBS seismic program was acquired for Pemex over the Cantarell field offshore Mexico to improve the structural definition of the deeper Sihil field underlying the giant Akal field. The acquisition was made using autonomous receivers planted with accurate positioning on a regular grid in the seabed. The data is acquired
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Anisotropic Analysis of 3C Data and Comparison to 9C Data
Authors J.E. Gumble, J.E. Gaiser and R.H. TathamA29 ANISOTROPIC ANALYSIS OF 3C DATA AND COMPARISON TO 9C DATA 1 J. E. GUMBLE 1 J. E. GAISER 2 AND R. H. TATHAM 1 1 The University of Texas Jackson School of Geosciences Department of Geological Sciences 1 University Station C1100 Austin Texas 78712-0254 USA 2 WesternGeco Denver CO 80202 USA Abstract Polarization analysis was conducted using both direct controlled source polarization shear wave (9C) data and converted shear wave (P-SV) data recorded for several source-receiver azimuths in both isotropic and anisotropic media. Anisotropic results are obtained using various methodologies including but not limited to four component rotation analysis
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PS-wave and P-wave Azimuthal Anisotropy in a Carbonate Basin
Authors B. Mattocks, D. Todorovic-Marinic, J. Li, S.L. Roche and S. Ronen1 A30 PS-WAVE AND P-WAVE AZIMUTHAL ANISOTROPY IN A CARBONATE BASIN B. MATTOCKS 1 D. TODOROVIC-MARINIC 2 J.LI 1 S. L. ROCHE 1 and S. RONEN 1 1 Veritas DGC Inc. 10300 Town Park Dr Houston TX 77072 USA 2 Veritas GeoServices Summary In an onshore example from a carbonate basin the cumulative PS-wave anisotropy is in good general agreement with regional horizontal stress from borehole breakouts and with symmetry plane orientations determined from azimuthal variations in the AVO gradient of the conventional P-wave 3-D survey. The embedded multicomponent test exhibits all the expected characteristics of converted waves in azimuthally
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Borehole Calibration of PS-Waves for Fracture Characterization – Pinedale Field, Wyoming
Authors J.E. Gaiser and R.R. van DokA31 BOREHOLE CALIBRATION OF PS-WAVES FOR FRACTURE CHARACTERIZATION – PINEDALE FIELD WYOMING Summary 1 J. E. GAISER AND R. R. VAN DOK WesternGeco 1625 Broadway Suite 1300 Denver Colorado 80202 USA Converted-wave (PS-wave) 3D surveys where downgoing compressional (P) waves convert to upgoing shear (S) wave reflections provide a practical means to obtain S-wave anisotropy attributes for characterizing fractures. This is particularly important for delineating naturally fractured reservoirs by exploiting the unique characteristics of S-wave splitting in azimuthally anisotropic media. An important aspect of this process that is often missing is to use borehole fracture information for calibrating the anisotropy.
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Improving the Definition of Shear Wave Splitting Attributes
Authors R.J. Garotta, P.Y. Granger and H. DariuA32 IMPROVING THE DEFINITION OF SHEAR WAVE SPLITTING ATTRIBUTES R.J. GAROTTA P.Y. GRANGER H. DARIU Abstract ������������������� ����������� � ���������� �� α �� ������ ����������� �� �� � � �� �� � ��� � α � �� ��� � ���α ���α � �� �� � ��� � α � �� ���� �� ���α ���α Fig 1a Fig 1b Figure 1: Radial and transverse acquisition coordinates and natural coordinates (1a) convolution operators resulting from travel through the anisotropic layer (1b) � 1 The effects of birefringence or shear wave splitting on a single raypath recorded with a good signal-tonoise ratio can
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Vp/Vs from Two Different Mode Converted Arrivals
Authors D. Ebrom, P. Heppard, M. Albertin, S. Viceer, P. Garossino and L. ThomsenA33 VP/VS FROM TWO DIFFERENT MODE CONVERTED ARRIVALS Abstract 1 Both the locally converted C-wave and the Purnell mode (S-wave) can be used to determine the Vp/Vs ratio beneath salt. These Vp/Vs ratios can be transformed into pore pressures to guide drilling activities. We forward modeled a generalized flat layered earth with a thick salt body in a deepwater setting. The reduced C-wave and Purnell mode traveltimes can be easily converted into Vp/Vs ratios when combined with the P-wave traveltime. The Vp/Vs so deduced from traveltime measurements is exactly correct only for an exactly vertical ray but acceptable (less than
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Documented Applications of S-Wave Data
By R.H. TathamA34 DOCUMENTED APPLICATIONS OF S-WAVE DATA 1 Introduction For the past twenty-five years seismic shear wave data have been sparingly applied in the petroleum exploration and production industry. Early applications required direct sources of shear-wave energy and thus data acquisition was generally limited to land locations. Further concerns about receiver coupling also limited recording of mode-converted shear waves from conventional sources to land environments. In recent years multicomponent seismic data acquisition has been successfully extended into the marine environment through 3C and 4C sea-floor recording using conventional airgun sources. These data have been quite effectively recorded and processing capabilities are
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Multicomponent Processing and Analysis of a 3D/9C Survey over an Algal Mound Carbonate Reservoir in the Paradox Basin – Roadrunner Field, Colorado
Authors R. van Dok, J. Gaiser, P. La Pointe and R. BensonA35 MULTICOMPONENT PROCESSING AND ANALYSIS OF A 3D/9C SURVEY OVER AN ALGAL MOUND CARBONATE RESERVOIR IN THE PARADOX BASIN: ROADRUNNER FIELD COLORADO Summary 1 The Paradox Basin in southwestern Colorado contains several isolated carbonate reservoirs created by algal limestone buildups. These algal mounds are relatively straightforward to locate on conventional P-wave seismic data. The reservoirs however are generally not internally homogeneous and ultimate recovery depends on locating zones of increased porosity and permeability. In 2003 a nine-component (9-C) 3-D survey was acquired over the Roadrunner Field in the Paradox Basin northwest of the town of Tawaoc (Figure 1) in order
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Imaging through Gas Using 2D-3C Data and Well Logs – Case Study from North Africa
Authors J. Brunelliere, A. Laake, T. Marples, E. Loubens and F. van KleefA36 IMAGING THROUGH GAS USING 2D-3C DATA AND WELL LOGS - CASE STUDY FROM NORTH AFRICA Abstract 1 Shear waves can help imaging through gas-filled sediments. Many offshore examples have been published (Granli et al. 1999; McHugo et al. 1999) whereas onshore case histories are rare. In this project from North Africa onshore converted waves were processed to image complex gas-filled zones. The first phase of the project was performed without available well data. This paper focuses on the two main challenges of this processing project: the noise attenuation process and the improvement of migration models using well velocities. It
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Vector Fidelity of Land Multicomponent Measurements in the Context of the Earth-Sensor System
Authors D. Burch, A. Calvert and J. NovakP01 VECTOR FIDELITY OF LAND MULTICOMPONENT MEASUREMENTS IN THE CONTEXT OF THE EARTH-SENSOR SYSTEM Summary 1 When land multicomponent seismic data are to be used to image converted wave energy or for shear splitting analysis the orientation of the three measurement directions must be known. Further the vector fidelity of these measurements should be high. In this context vector fidelity means that the vector motion of the sensor is correctly resolved along the three orthogonal directions of measurement and that the Earth near the sensor behaves according to a 1-D isotropic model. If either of these assumptions is violated estimates
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4D Rapid Turnaround for Permanent 4C Installation
Authors R.A. Clarke, O.J. Askim, K. Pursley and P. VuP03 4D RAPID TURNAROUND FOR PERMANENT 4C INSTALLATION Summary 1 We present a case study of using permanently installed ocean bottom cables and a small computer cluster on the platform to dramatically reduce turn around time for full depth migrated 4C4D volumes. We installed a small Linux cluster on the Valhall platform and used it to perform some preprocessing on the data as it was being acquired. The data were then compressed and transmitted to BP’s Houston high performance computing center for sorting and depth migration. One of the main ideas is that when the last shot in the survey
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Making the Business Case for Permanent Marine Multi-Component Systems
By M.H. HoustonP04 MAKING THE BUSINESS CASE FOR PERMANENT MARINE MULTI-COMPONENT SYSTEMS Summary 1 This presentation contrasts permanent multi-component systems with alternative marine acquisition methods and identifies key technical and economic tradeoffs for each technology. A simple production model demonstrates the role of investment production and 4-D attribution for pay-back from a permanent multi-component marine system. Sensitivity analyses on several investment and pay-back scenarios illustrate key business strategies for asset managers. Introduction Valhall installed in 2003 as the first permanent multi-component (PMC) system for acquiring repeated 4-D images has been a dazzling technical success. The system has demonstrated an ability to acquire
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Seismic Signatures of Two Orthogonal Sets of Vertical Microcorrugated Fractures
Authors R.F. Fuck and I. TsvankinP05 Abstract SEISMIC SIGNATURES OF TWO ORTHOGONAL SETS OF VERTICAL MICROCORRUGATED FRACTURES R. F. FUCK 1 and I. TSVANKIN 2 1 Reservoir Characterization Project Colorado School of Mines Golden CO 80401-1887 USA 2 Center for Wave Phenomena Colorado School of Mines Golden CO 80401-1887 USA Conventional fracture-characterization techniques operate with the idealized model of penny-shaped (rotationally invariant) cracks and ignore the roughness (microcorrugation) of fracture surfaces. Here we develop analytic solutions based on the linear-slip theory to examine wave propagation through an effective triclinic medium that contains two microcorrugated vertical orthogonal fracture sets in isotropic background rock. The corrugation of
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Sensitivity of P-P and P-SV AVO Reflectivity to Fluid Properties in Porous Media – Extension of P-P Results and P-SV Investigation
Authors R.H. Tatham and K.A. BainP06 SENSITIVITY OF P-P AND P-SV AVO REFLECTIVITY TO FLUID PROPERTIES IN POROUS MEDIA: EXTENSION OF P-P RESULTS AND P-SV INVESTIGATION Abstract 1 The objectives of this investigation is two-fold: First to extend the examination of the dynamic effects of variations in relevant fluid properties (permeability and fluid viscosity) on the total P-P wave reflectivity variations with angle of incidence. The reflecting boundaries considered are limited to the interface between two different fluids within a common reservoir sand extending a previous preliminary study but including a realistic description of the fluid models. For fluid-fluid reservoir contacts the AVO effects were
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Geometric Attribute Analysis of 3D PS-Converted Waves
Authors C. D‘Agosto, K. Marfurt and R.J. MichelenaP07 GEOMETRIC ATTRIBUTE ANALYSIS OF 3D PS- CONVERTED WAVES Abstract 1 Introduction. Geometric 2 attributes in particular seismic coherence have been widely used in the last years to analyze 3D seismic data since a classic paper by Bahorich and Farmer in 1995. However most of the experience that has been reported so far in the use of geometric attributes is related to conventional 3D P-wave seismic data. There is less experience in the use of geometric attributes to analyze 3D multicomponent data. In this paper we show examples of the use of geometric attributes to analyze 3D PS converted waves
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PP and PS Polarities in Correlation of Events and Approximating RPS for AVO
Authors R.J. Brown and A. VanntP08 PP AND PS POLARITIES IN CORRELATION OF EVENTS AND APPROXIMATING RPS FOR AVO Summary 1 R.J. BROWN 1 2 and A. VANT 1 3 1 University of Calgary Department of Geology & Geophysics Calgary Alberta Canada T2N 1N4 2 University of the Faroe Islands Faculty of Science & Technology PO Box 2109 FO-165 Argir Faroe Islands 3 Enervant Consulting Ltd For most interfaces RPP and RPS have opposite sign which means an event usually has the same display polarity on PP and PS seismic sections. In processing and interpreting PS sections we usually rely on correlation of corresponding PS
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Borehole Vicinity Acoustic Properties Study Using Offset VSP Data
Authors A. Tikhonov and V. SteninP09 BOREHOLE VICINITY ACOUSTIC PROPERTIES STUDY USING OFFSET VSP DATA Abstract 1 Acoustic properties of the geological section present the source of data for estimation of such important reservoir characteristics as lithologies or porosity. The advantages of borehole seismic over the surface seismic make VSP data attractive for the use in calculations of high-resolution acoustic and shear elastic impedance sections. On the other hand there are a number of factors distorting amplitude anomalies related to acoustic properties variations. This paper describes the attempt to develop a technique for offset VSP data processing preserving true amplitudes. Study Motivation Nowadays inversion of
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Full-Wave Attributes for Multicomponent Data Interpretation
By K. ZouP10 FULL-WAVE ATTRIBUTES FOR MULTICOMPONENT DATA INTERPRETATION Abstract 1 Seismic attributes that provide useful interpretation information have been primarily based on PP reflections thus far. Along with the development of multicomponent technology seismic attributes may be extended to include converted PS reflections. In this paper we describe the concept of fullwave attributes that use not only PP reflections but converted-wave (PS-wave) seismic data and joint PP/PS information also. Several meaningful physical definitions of full-wave attributes are provided. Real full-wave attribute results using PS and PP/PS joint inversion in the Gulf of Mexico are presented. By comparing with known production data
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Rapid Variations of Azimuthal Anisotropy of Near Surface (Eastern Siberia)
Authors W.V. Karsten, S.B. Gorshkalev, K.A. Lebedev, I.V. Korsunov and V.S. ParasynaP11 RAPID VARIATIONS OF AZIMUTHAL ANISOTROPY OF NEAR SURFACE (EASTERN SIBERIA) W.V.KARSTEN 1 S.B.GORSHKALEV 1 K.A.LEBEDEV 1 I.V.KORSUNOV 2 V.S.PARASYNA 3 Abstract 1 1 Institute for geophysics SB RAS 3 acad. Koptyug ave. 630090 Novosibirsk Russia EAGE/SEG Research Workshop – Pau France 5 – 8 September 2005 2 JSC Eniseygeofizika 3 JSC Gazprom Azimuthal anisotropy of near surface as studied with P- and S-waves data is widely spread in the Urubchen-Tokhomo Zone (UTZ) in the Eastern Siberia and the degree of this anisotropy is very high. It is characterized with rapid lateral changes not only in quantity but in symmetry
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Polarization Analysis on Seismic Data after Multicomponent Wavefield Filtering
More LessP12 POLARIZATION ANALYSIS ON SEISMIC DATA AFTER MULTICOMPONENT WAVEFIELD FILTERING Abstract 1 C. PAULUS J. I. MARS Laboratoire des Images et des Signaux Institut National Polytechnique de Grenoble BP 46 Saint Martin d’Hères France Seismic exploration and reservoir study require information conveyed by reflecting waves. In case of multicomponent dataset (3C 4C…) classical methods such as FK filtering τ-p filtering SVD give relatively poor results since they do not take into account all the information conveyed by multicomponent sensors or they require pre-processing. Recently we’ve developed an extension of the Spectral Matrix Filtering method (SMF) called MultiComponent WideBand Spectral Matrix
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The Polarization Stack – A Multicomponent Attribute Derived from Vector Infidelity
By J. DellingerP13 Summary THE POLARIZATION STACK: A MULTICOMPONENT ATTRIBUTE DERIVED FROM VECTOR INFIDELITY J. DELLINGER BP EPTG 501 Westlake Park Blvd Houston Texas 77079 USA I present a technique that is analogous to NMO and stack in that it sums over hyperbolic moveout trajectories. However unlike NMO and stack it also collapses the component and time dimensions within a chosen window. Polarizations cannot be summed as scalars; the result of a polarization stack is a matrix that represents the least-squares best-fitting linear relationship between the vector offset and the recorded polarization averaged over all offsets and times within the chosen stacking
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Non-Linear AVA-Inversion with Prior Information
By B.E. RommelP14 NON-LINEAR AVA-INVERSION WITH PRIOR INFORMATION Abstract 1 AVA-inversion uses dynamic (viz. amplitude) information of reflection data. While conventional linear 3-term AVA-inversion determines elasticity and density contrasts between two halfspaces nonlinear AVA-inversion as presented here determines elasticity and density directly and it does so in an accurate way. Furthermore non-linear AVO-inversion even benefits from large incidence angles and large elasticity or density contrasts thus allowing the use of the most informative data. Prior information however is required to stabilize the inversion. Introduction 3-term AVA-inversion is usually deemed to be prone to errors but with improved data accuracy – calibrated sources
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Multicomponent SWD
Authors G. Bernasconio and M. VassalloP15 MULTICOMPONENT SWD G. BERNASCONI M. VASSALLO Abstract 1 Multicomponent seismic provides direct information about both compressional and shear properties of the subsurface. During the drilling process this information can be crucial to predict overpressured zones and to reduce the ambiguity between variations in pore pressure and variations in lithology. We investigate some aspects of the multicomponent processing in SWD acquisitions. We use the radiation pattern of a working roller-cone drill bit to analyze the subsurface illumination in simple models. Then we migrate synthetic data in order to highlight the information that can be recovered by using P- and S-waves
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Joint PP and PS Stratigraphic Inversion for Prestack Time Migrated Multicomponent Data
Authors D. Mace, Y. Agullo, K. Labat, T. Tonellot, A. Bourgeois and M. LavielleP16 JOINT PP AND PS STRATIGRAPHIC INVERSION FOR PRESTACK TIME MIGRATED MULTICOMPONENT DATA Summary 1 The goal of this paper is to improve the determination of a target zone located in a slowly laterally varying background by jointly inverting PP and PS waves available in prestack time migrated multicomponent data while taking into account a priori information (well log data geological knowledge...) in the inversion process: an optimal elastic model is estimated together with an optimal correspondence between PP and PS events. The methodology and results are illustrated on a 2D realistic synthetic example. Introduction YOHAN AGULLO* DANIELE MACE KARINE
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The Application of Joint P-Wave and PS Converted Wave in Detecting of Gas Reservoir
More LessP17 THE APPLICATION OF JOINT P-WAVE AND PS CONVERTED WAVE IN DETECTING OF GAS RESERVOIR Abstract 1 The use of converted PS-waves to image reservoirs with low P-wave impedance but high S-wave impedance has attracted considerable interest in offshore exploration. However little progress has been made on the application of converted wave technology to onshore exploration. Here we present an example of using converted-wave for characterizing onshore gas reservoirs in the Ordos basin in Northwest China. The Ordos basin is the largest gas province in China. The main gas reservoirs are upper Paleozoic sandstone that has low or reversed P-wave
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Applying Advance Processing to Enhance Seismic Interpretation Farigh Area Eastern Basin, Libya
More LessP18 APPLYING ADVANCE PROCESSING TO ENHANCE SEISMIC INTERPRETATION FARIGH AREA EASTERN SIRTE BASIN LIBYA 1 1 1 2 R. KHALIL A. NAJAH & F. BELHAJ 1 Veba Oil Operations P O Box 690 Tripoli Libya 2 th TPOC Exploration Dept. Burj Al Fatah 9 Floor-Tripoli Libya The Farigh Oil Field is located in eastern Sirt Basin. The basin is considered the most prolific hydrocarbon in North Africa (Figure 1). The intracratonic rifted Sirte Basin started during the Lower Cretaceous time and ended in the Tertiary time. The basin was formed by a series of horsts and grabens resulted from the
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