EAGE/SEG Research Workshop - Multicomponent Seismic - Past, Present and Future

A02 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

A04 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

A06 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

A08 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.

A10 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

A12 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

A14 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

A16 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

1 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

A20 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