- Home
- Conferences
- Conference Proceedings
- Conferences
2nd EAGE St Petersburg International Conference and Exhibition on Geosciences
- Conference date: 16 Oct 2006 - 19 Oct 2006
- Location: Saint Petersburg, Russia
- ISBN: 978-90-73781-64-1
- Published: 16 October 2006
61 - 80 of 209 results
-
-
Innovative Depth Imaging in Complex Permafrost - The Taglu 3D PSDM Project
Authors G.L. Reed, P.H. Chang and K.F. BrittleInnovative new velocity model building approaches developed for a recent, successful anisotropic 3-D prestack depth imaging project from surface through the complex permafrost layer above the Taglu Gas field are presented. Discovered and delineated in the early 1970's by Imperial Oil , Taglu is a giant gas-condensate field located onshore in the Mackenzie Delta region of Arctic Canada, approximately 120 km north-northwest of the City of Inuvik.
The final Taglu APSDM seismic volume is considered a greatly improved structural image over previous time imaging products. Structural imaging now conforms to the available field well data, with the mapped seismic structure closing for the first time on the known GWC depth without adjustment. In addition, DHI image quality has improved substantially and independent confirmation of DHI structural conformance is now clearly demonstrated directly in the seismic data.
-
-
-
Gaussian Beams Based True Amplitude Imaging
Authors V.A. Tcheverda and M.I. ProtasovWe present an original approach of true amplitude seismic imaging by means of weighted summation of multi-shot multi-offset data. In order to compute these weights one should trace Gaussian beam starting from some current point within target area towards acquisition system. The special choice of Gaussian beam provides possibility in advance to take into account geometrical spreading and illumination condition for specific acquisition system. Global Gaussian beam regularity enables one to deal with central ray field with any kind of singularities.
-
-
-
Depth Imaging of 2D Data Using 3D Grid-Based Tomography
Authors A. Zarkhidze, T. Grechishnikova and D. YanchakA description of the workflow of successful application of 3D grid-based tomography to 2D seismic data in the area of a complex weathering zone. This approach allows to incorporate refraction wave-based velocity information into a depth velocity model to properly handle actual raypaths through the near surface.
-
-
-
Correcting Long-Wavelength Traveltime Distortion in the Presence of Inhomogeneous Permafrost Using Grid-Based Tomography
Authors T. Grechishnikova, A. Zarkhidze, D. Yanchak and R. MayThis paper describes a process of depth-velocity model building in the shallow subsurface using grid-based tomography in order to properly compensate for the long-wavelength distortion in the traveltimes.
-
-
-
VSP – Beyond Time-to-Depth
Authors B.E. Hornby, J. Yu, J.A. Sharp, A. Ray and Y. QuistVSP or Vertical Seismic Profile was originally designed and is currently primarily used, to give us time-to-depth for seismic well tie. Beyond time-to-depth a number of possibilities exist. Recently, there has been considerable interest in VSP imaging, with extensive surveys being acquired both on land and offshore. Modeling studies using full-waveform finite-difference method (FDM) show us what we can image for a particular acquisition geometry and geology, with best image results seen with 3D VSP surveys incorporating a large VSP array in the well and a 2D source pattern acquired using a surface seismic shooting vessel. Traditionally, VSP imaging has been implemented using surface seismic processing algorithms. However, the VSP geometry poses its own challenges and unique opportunities. In this article we explore some imaging methods to attempt to take advantage of the VSP geometry. In addition we discuss the use of permanent in-well seismic sensors for reservoir monitoring.
-
-
-
A Method for 3D Surface-Related Multiples Prediction in Case of Coarse Sampling
Authors E. Kurin, M.S. Denisov and D. LokshtanovA method for 3D surface-related multiple prediction (SRMP) is suggested. It uses both raw common source gathers and azimuth-dependent inverse-NMO corrected traces of a stack cube, or a CMP gather, to produce common-source gathers of multiples. The application of the method is illustrated on a complex real dataset.
-
-
-
Robust Methods of Adaptive Seismic Multiple Suppression
Authors M.S. Denisov, M.A. Polubojarinov and D.B. FinikovOne of the widely used approaches to multiple suppression is a two-step scheme. In the first step, multiples are predicted. In the second step, multiples are adapted to the input data with matching filters and subsequently subtracted. It is known that a non-stationary adaptation is usually required. A method for computation of smoothly varying matching filters is proposed. The behavior of the non-stationarity is parameterized with decomposition of the variations into a set of smooth basic functions. Besides, substantial improvement is usually achieved by application of multichannel adaptation. Such approach requires a multichannel version of the Levinson’s algorithm, but the computations loose their stability. An iterative robust procedure that does not require regularization is proposed to improve the stability of the scheme.
-
-
-
The Medium Directional Vision Time Section in a Seismic Survey by Works of Multifold Coverage
More LessThe new approach to creation the special seismic record by works of multifold coverage - the common deep area (CDA) gather is offered. The reflection time-distance equation of the CDA method is resulted. On the basis of numerical modeling is shown, that seismic records of multifold coverage allow confidently carrying out definition of spatial coordinates of reflecting boundary – dip azimuths and reflector dip. The new modified common-offset gather and new technology of time section formation (the medium directional vision time section) is offered.
-
-
-
Statics Estimation and Raw Data Quality Control in CDP Data by Means of POLYCOR Method
Authors A.V. Kopchikov, A.A. Tabakov and V.N. FerentsiPOLYCOR is an alternative method of static shifts correction in CDP data processing based on multiple correlations. It is based on four-factor model of time shifts. This model includes kinematical shifts, dip shifts and shot point (SP)/ observation point (OP) statics. POLYCOR method features high noise immunity. Accuracy of SP and OP statics determination in practice does not depend on shift values (for wide range of shift values). When using this method it is not necessary to involve a priori estimation of velocity. Paper contains description and efficiency estimation of POLYCOR method. Efficiency estimation is based on the synthetic data experiment. Results of synthetic data experiment are described and illustrated. Synthetic data experiment results confirm that an accuracy of SP static determination does not depend on a priori defined SP static shifts. Presence of white noise signal in most case does not affect accuracy and reliability of algorithm.
-
-
-
Current Demands to Accuracy of Near-Surface Studies for Performing CDP Reflection Surveys
Authors YU.N. Dolgikh, S.I. Shulik and I.N. BerdyuginSteady toughening of demands to accuracy of seismic exploration results against amplitude contraction and reduction of prospect-target areas being brought into operation is a present-day tendency seen in West Siberia. A complex but rather urgent practical task of CDP reflection surveying is to identify low-amplitude small-sized and shallow-buried (at level of S-G horizons) targets which presence in a wave field of time sections is hidden by near-surface velocity inhomogeneities, i.e. when a near-surface factor is dominant or comparable to a structure factor. It is necessary to provide a proper accuracy of near-surface inhomogeneities corrections in the conditions typical for northern areas of West Siberia. To perform accurate correction for near-surface structures, it is necessary to apply special near-surface targets’ observation systems, for example: multi-level seismic technologies that envisage use of several receiving systems different in their specification parameters. A report gives a brief overview of the existing approaches to near-surface correction, as applied, mainly, to weathering and permafrost zones; draws attention to distortion effects of these inhomogeneities; formulates methodic conditions at which a seismic exploration method provides the accuracy needed.
-
-
-
Azimuthal Anisotropy in Marine Streamer Data
Authors G. Williams and R.J. WombellTowed-streamer acquisition samples a narrow range of azimuths. We discuss the resulting sensitivity of such data to azimuthal velocity anisotropy. Correction for such effects, using either a residual moveout correction before migration or incorporating the anisotropy within the migration step itself, can significantly improve the imaging of the data.
-
-
-
Massive 3D VSP Data Migration with Energy Hashing Technique
Authors V.A. Mishin, S.I. Alexandrov and V.H. KivelidyNew migration technique of massive 3D VSP data is presented. The method is based on energy hashing algorithm. This technique is designed to enhance the quality of seismic images of complex geological structure under limited priory information. The method effectiveness is demonstrated on experimental data processing result.
-
-
-
3D Acquisition Geometries as the Way to Overcome Drawbacks of Today's Seismic Exploration Technologies
By A.A. TabakovThe need for highly detailed investigation of complicated and small reservoirs as well as efficient extraction of residual resources from mature deposits has been constantly growing in recent years. This fact sets up new requirements to efficiency of implemented geophysical exploration methods and first of all seismic methods as the main tool for hydrocarbon reservoirs study. In this paper exploration abilities of modern land and borehole seismic are discussed. Their general features, resolution power and accuracy are mentioned and principal shortcomings are formulated. Integrated surface-downhole seismic acquisition geometries are proposed as the way to compensate specific drawbacks of land seismic and VSP. Case stories prove the efficiency of the new acquisition system.
-
-
-
Post-Stack Velocity Analysis by Separation and Imaging of Seismic Diffractions
Authors S. Fomel, E. Landa and M.T. TanerSmall geological features manifest themselves in seismic data in form of diffracted waves, which are fundamentally different from seismic reflections. Using two field data examples, we demonstrate the possibility of separating seismic diffractions in the data and imaging them with optimally chosen migration velocities. Our criterion for separating reflection and diffraction events is the smoothness and continuity of local event slopes. Our criterion for optimal focusing is the local varimax measure. The objective is fast velocity analysis in the post-stack domain and high-resolution imaging of small-scale heterogeneities. Our examples demonstrate the effectiveness of the proposed method for high-resolution imaging of such geological features as faults and salt boundaries.
-
-
-
Gas-Field Prediction in Transit Zone Based on Seismic Tomography Data
Authors Y.V. Roslov, N.T. Dergunov, N.N. Efimova and T.S. SakoulinaLong offset seismic data acquisition in shallow water allows the use of complex seismic tomography technology for gas-field prediction. The technology is based on the a complex processing of refracted and reflected waves. The effectiveness of the complex seismic data processing was evaluated on a test model and on seismic data acquired in a shallow-water zone of Ob Bay. Low velocity anomalies detected with seismic tomography correspond to anomalous dynamic parameters of seismic data and morphological evidences within this explored gas-field.
-
-
-
Local Disturbances Cut off by Nonlinear Estimation of Trends
Authors A.V. Masjukov and V.I. ShlyonkinA new nonlinear method is proposed for attenuation of noise, which spatial width is a priory bounded above. The algorithm is based on successive rejections of digital signal points used for trend estimation.
-
-
-
Geological Disintegration Zones and Their Representation in the Fields of Reflected and Scattered Waves
Authors S.I. Shlionkin, V.A. Ganiev and G.V. KashirinThe vertical geological structure disintegration, appearing as a result of depth tectonic processes, in most cases is a determing factor in generation of oil and gas accumulations. Locations of many hydrocarbon deposits are confined to tectonic active zones. Geological disintegration leads to formation of a deep-seated structure of gas-liquid migration channels. It has also an influence on filtration-accumulation properties of already formed epigenesis sediments. We suppose that the channels of vertical disintegration may be considered as self-dependent geological objects to which hydrocarbon traps are confined. The paper is devoted to the problem of investigation, detection and exploration of such objects by new seismic technologies.
-
-
-
A Simple Seismic Data Discovery Portal for Scientific Collaborative Research
More LessAn Open Source web based Discovery portal is presented, that aims to support scientific collaborative work in the field of Seismic Data analysis. Based on the Simple Object Access Protocol (SOAP) it allows setting up a layer of networked archives where data and metadata can be easily found and shared. Data structure and methods are kept as simple as possible, to avoid, on one side, the need of human interaction (a cost that small institutions cannot afford), and on the other side to obtain a lightweight and flexible tool that could easily be used in a non prescriptive environment as Scientific Research.
-
-
-
Review of Missions, Strategies and Solutions for Effective IT in E&P
By K.N. TimakovReview of modern IT technologies, their strategies, major problems and solutions for E&P and knowledge management.Complex analysis of IT applied in E&P, based on open sources publications for last 5 years.
-
-
-
A New Approach to Interpreting and Holding Geologic-Geophysical Data on the Basis of Geoinformation Technologies and Principles of Fractal Analysis
Authors A.A. Simanov and A.V. PuginAt present the complex analysis of the whole available information about the subjects of inquiry occupy an important place in interpretation process. In this paper we propose a new approach to interpreting and holding of geologic-geophysical data based on joint use of geoinformation technologies, fractal analysis and approximation by equivalent sources.
-