66th EAGE Conference & Exhibition

P282 OIL – SOURCE ROCK CORRELATION IN LUBLIN AREA (POLAND): GEOCHEMICAL APPROACH 1 D. WIECLAW 1 M.J. KOTARBA 1 T. WILCZEK 2 1 AGH University of Science and Technology Faculty of Geology Geophysics and Environmental Protection Mickiewicza Ave. 30 30-059 Krakow Poland 2 Polish Oil and Gas Company Jagiellonska St. 76 03-301 Warsaw Poland SUMMARY The Lublin Trough is one of the biggest petroleum basins in Poland. Results of pyrolytic Rock Eval stable carbon isotope and biomarkers analyses of 191 core samples reveal that oil-prone kerogen (Type II) dominate in Silurian Devonian and Lower Carboniferous strata and gas-prone (Type III)

P284 LARGEST WEST SIBERIA OIL AND GAS BEARING BASIN: GIANT AND UNIQUE PETROLEUM SYSTEM Farman K. Salmanov (ITERA) Alla Nemchenko-Rovenskya (VNIIGeosystem) Vilen Gavura(SibNeft) Tatyana Nemchenko (PetroAlliance) 1 The West Siberian Province is the largest oil-and gas bearing province recognized on Russian territory. The Northern part of the provinces (Nadym-Pur Pur-Taz Yamal and Gydan) are predominantly gas bearing. Other as Pre-Ural and Frolov in the west of the province Sredny Priob and Kamys in central part and Vasyugan and Paidugin in the east are predominantly oil bearing. One characteristic feature of the West Siberian is a large number of giant fields.

P291 ASSESSING THE IMPACT OF SOURCE SIZE ON PS-WAVE REFLECTIONS – OFFSHORE QATAR 1 Abstract We investigate the effect of airgun source size on mode-converted shear-wave reflections recorded by an OBC survey offshore Qatar. The analyses are based on a series of repeat 2D test-lines acquired over the same OBC receiver layout. Both pressure-wave (PP-wave) and mode-converted shear-wave (PS-wave) data were processed through to final migration on each test-line. Subsequent signal analysis showed a consistent response at target level with only small changes in signal-to-noise content within the range of gun-sizes used. Introduction J. Holden E. Angerer N. Jones (CGG

P293 VECTOR FIDELITY CHARACTERIZATION OF A MARINE MULTI-COMPONENT ACQUISITION SYSTEM Summary 1 Vector fidelity is a desirable characteristic for a multi-component acquisition system. An acquisition system with poor vector fidelity generates data which if uncorrected will lead to subsequent errors in processing and a lack of confidence in final interpretations. To quantify the vector fidelity of a new marine multi-component acquisition system extensive wide azimuth data was collected and analysed. Direct arrivals acquired from dense shot grids are analysed using linearity metrics and coupling correction matrices. A high degree of linearity typically in excess of 0.99 shows the system to

P295 VALIDATING THE BASIC ASSUMPTIONS IN A VIBRATORY SOURCE SIGNAL ESTIMATION METHOD Abstract 1 In the past few years a wavelet transformation based analysis tool was developed to extract information from geophone signals on source generated distorted output during reflection seismic measurements. With the help of the method it is possible to derive the signals’ higher harmonic components relative to the fundamental part. Based on the observations I also proposed a method which combines measured vibratory ground force signals and the estimated relative data to approximate the true distorted vibrator output signal. The basis of the combination is that the

P301 WAVELETS WITHOUT WELLS – VIA PRESTACK INVERSION Summary 1 In this paper we demonstrate an inversion methodology to extract a source wavelet from each prestack gather. This inversion estimates and deconvolves the effective source contribution within an interval of interest at the same time characterizing AVO with high resolution. We demonstrate with field data that: (1) the wavelets estimated by inversion compare favorably with a wavelet derived from well control and (2) the inversion recovers wavelet phase to within at least 15° for these data. Since the inversion estimates a wavelet for each input gather one may also track

P303 CONVERTED WAVE STATICS CORRECTION BY INVERSION OF CRS TRACE TIME SHIFTS Abstract 1 We present a new method for resolving converted wave receiver statics based on inversion theory. The statics are obtained by minimizing the trace-to-trace time differences of target reflectors in the Common-Receiver Stack (CRS). In general most erroneous time picks are associated with weak crosscorrelation. The method can better handle the uncertainty of time picks in presence of noise because we use the crosscorrelation coefficients as weights in the inversion. The weights ensure that the time delays picked with weak crosscorrelation have less contribution to the solution

P305 THE IMPACT OF DATA PRE-PROCESSING ON SUB-BASALT SEISMIC IMAGING 1 A. DRUZHININ 1 R. W. HOBBS 2 and X-Y. LI 1 1 British Geological Survey Murchison House West Mains Road Edinburgh EH9 3LA UK 2 Dept. of Earth Sciences Durham University South Road Durham DH1 3LE UK Summary Source deconvolution with de-ghosting surface multiple suppression and wavefield separation are essential pre-processing steps prior to seismic imaging in complex areas. We study the impact these data pre-processing methods have on wave-mode dependent sub-basalt imaging. Long-offset data from a recent marine streamer survey in the Faeroes-Shetland Basin were reprocessed using various

P 307 AVA inversion using real-coded genetic algorithm SUMMARY S. CHAKRABORTY 1 S. PHADKE 2 and R. K. VERMA 3 1 Centre for Development of Advanced Computing (C-DAC) Pune - 411007 India 2 Formerly with C-DAC now with Reliance Industries Ltd. Oil & Gas Division Navi Mumbai - 400709 India 3 GEOPIC ONGC Dehradun - 248195 India AVA (Amplitude variation with angle) inversion is becoming popular in oil & gas exploration with the advancement in the High Performance Computers. AVA inversion is used for estimation of elastic parameters from prestack seismic data. In this article we present a 1D seismic

P311 Modeling Tubewave Effects In Seismic Wave Simulations. Abstract 1 AUTHORS R.T. COATES 1 CHUNLING WU 2 L. EISNER 3 The borehole has a significant effect on the acoustic wavefield radiated from a downhole source. Similarly the borehole has a significant effect on the signal received by downhole receivers. At high frequencies in excess of 1 kHz these effects are a complex interaction of compressional shear flexural and fluid-borne modes. However at seismic frequencies below 1 kHz the generation and propagation of tubewaves are the dominant effects. Thus in borehole seismic modeling it is important to include tubewave effects to