The Eocene-Oligocene Annot Sandstone of South East France is a sand-rich turbiditic system, up to 1000 m thick, which was deposited in several parallel and tectonically controlled sub-basins. For reservoir characterization purposes, three kilometer-scale outcrop areas were studied in detail, resulting in bed-scale, 2D and 3D architecture descriptions.
Traveltimes from an offset vertical seismic profile (VSP) are used to estimate subsurface two‐dimensional dip by applying an iterative least‐squares inverse method. Tests on synthetic data demonstrate that inversion techniques are capable of estimating dips in the vicinity of a wellbore by using the traveltimes of the direct arrivals and the primary reflections. The inversion method involves a “layer stripping” approach in which the dips of the shallow layers are estimated before proceeding to estimate deeper dips. Examples demonstrate that the primary reflections become essential whenever the ratio of source offset to layer depth becomes small. Traveltime inversion also requires careful estimation of layer velocities and proper statics corrections. Aside from these difficulties and the ubiquitous nonuniqueness problem, the VSP traveltime inversion was able to produce a valid earth model for tests on a real data case.
Other| November 01, 1988 Apport de la sismique tres haute resolution multitrace a l'etude des sequences sedimentaires recentes A. Bourgeois; A. Bourgeois Author IFP, Rueil-Malmaison 92500, France Search for other works by this author on: GSW Google Scholar Gilles Lericolais; Gilles Lericolais Author Search for other works by this author on: GSW Google Scholar S. Berne; S. Berne Author Search for other works by this author on: GSW Google Scholar P. Magneville P. Magneville Author Search for other works by this author on: GSW Google Scholar Bulletin de la Société Géologique de France (1988) IV (6): 1039–1048. https://doi.org/10.2113/gssgfbull.IV.6.1039 Article history first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation A. Bourgeois, Gilles Lericolais, S. Berne, P. Magneville; Apport de la sismique tres haute resolution multitrace a l'etude des sequences sedimentaires recentes. Bulletin de la Société Géologique de France 1988;; IV (6): 1039–1048. doi: https://doi.org/10.2113/gssgfbull.IV.6.1039 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyBulletin de la Société Géologique de France Search Advanced Search This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not currently have access to this article.
Linearization is a goud approximation if the reference medium is sufficiently close to the actual one. The method we propose deals with a 1D reference medium and has been presented in Macé et al (1992). It is adapted to determine a 2D elastic target zone embedded in an almost laterally invariant elastic background. The method is based on the computation of the Jacobian matrix and uses a conjugate gradient algorithm to solve the optimization problem. In this paper, the linearized inversion method is valuated on synthetic prestack marine data from a gas-bearing sand model.
There has been a considerable amount of work to solve the linearized inversion of seismic data (Ikelle et al.,1988, Beydoun et Mendes, 1989, Lambare et al., 1992, Jin et al., 1992). We have proposed a 2D target-oriented prestack linearized inversion techniques using finite differences (Mace et al., 1989, Bourgeois et al., 1993). It considers that the actual medium is formed by small perturbations from an input plane stratified (1D) reference model, such that the Born approximation holds.
The goal of this paper is to determine what are the key factors for a successful prestack stratigraphic inversion. Sensitivity tests are performed on two synthetic data sets computed from a realistic 3D model. The first data set is generated using the same forward modeling as the one used in the inversion process and allows to evaluate separately the impact of different damaging factors. The second data set aims to mimic a more realistic context. The sensitivity tests show that prestack inversion results are very sensitive to inaccurate NMO corrections and wavelet estimation. On our example, random noise and uncorrelated organized noise over angles as well as reasonable inaccuracy of incidence angles estimation cause little damage to inversion results.
One of the advantages of seismic inversion methods in petroleum exploration is the potential quantitative evaluation of the distributed parameters (propagation velocity, acoustic impedance) which characterize subsurface formations. Such methods are particularly attractive for detecting stratigraphic traps, which can be recognized by a lateral variation in these parameters. Consequently, they can yield a substantial improvement over conventional pre-stack migrations which only provide images of heterogeneities.
Prestack linearized elastic inversion is an advanced approach for reservoir characterization compared to conventional AVO methods. The elastic parameters estimated at the reservoir level are a potential source of information on lithological, petrophysical and fluid variations. This paper develops a two-component prestack linearized elastic inversion which allows to determine a 2D elastic target zone embedded in an almost laterally invariant elastic medium. The interest of accounting for the two components in the inversion process is investigated on simple examples (scattering point, isolated reflector), then on a realistic synthetic example built from a North sea field. The elastic parameters obtained by inversion of the realistic case are interpreted in terms of reservoir properties in order to evaluate the contribution of the proposed method to reservoir characterization.
