66th EAGE Conference & Exhibition

P252 TIME SAG ANOMALIES VALIDATION BY MEANS OF THE P-P AND P-S SEISMIC DATA COMPARISON – THE CARPATHIAN FOREDEEP CASE Fig.1 The Carpathian Foredeep and the surrounding geological units. 1 The Carpathian Foredeep (CF) is the peripheral sedimentary foreland basin of the Alpine-age tectonic system created in relation to the moving Carpathians. It is extended along the Carpathian arc from Slovakia through Poland west-southern Ukraine to Romania. The big part of the foredeep covering about 18 000 km 2 is located in southern Poland. Fig.1 The hydrocarbon exploration was started here soon after the Second World War and during last

P254 PREDICTION OF HYDROCARBON’S DEPOSITS BY THE NEW METHOD OF SEISMIC DATA INTERPRETATION ON BLACK SEA SHELF (UKRAINE) Abstract 1 The prediction of hydrocarbon’s (HC) deposits was realized by the new method of seismic data interpretation proposed by well-known scientistgeophysicist of the XX century Yu.V.Timoshin and his colleague S.G. Semenova. The essence of this method is: not only HC deposits are imaged in seismic wave field (by amplitudes of reflected waves) but a very large volume of epigenetically changed rocks around and above the HC deposits is imaged in seismic field too. The investigation was carried out on the Shtormove

P257 OPTIMIZATION STRATEGY FOR SHARED EARTH MODELING Summary An optimization strategy for shared earth models is presented and discussed. True shared earth models should be represented in a way independent to the input requirements of the forward algorithms applied. This implies that realization processes invoked on the model are necessary in order to make the model available for all possible forward methods. The same independency must be addressed in the construction of the joint objective function by transforming the individual objective functions before the misfit is evaluated. Introduction The need of integrating and incorporating different observation types for the definition

P261 PRESTACK KIRCHOFF TIME MIGRATION FOR ANISOTROPIC MEDIA Abstract 1 Prestack Kirchhoff time migration for transversely isotropic media with a vertical symmetry axis (VTI media) is implemented using an analytical offset-midpoint traveltime equation; Cheop's pyramid equivalent equation for VTI media. This analytical equation is similar in structure to that of the familiar double-square-root (DSR) equation but far more complex. It includes higher order terms necessary to better handle anisotropy as well as vertical inhomogeneity. Application of the Kirchoff time migration method to the anisotropic Marmousi model and data demonstrates the effectiveness of the approach in better handling complex media in

P263 TIME AND DEPTH MIGRATION OPERATORS – CONTRACTOR VARIABILITY Summary 1 Migration is the second most important tool after stacking that we use to image reflections. The mechanics of the process are often poorly understood and whilst considerable amounts of time are spent ensuring “the velocities are correct” often little thought is given to the fidelity of the actual migration software being used. Investigations into how contractors use their software as part of a project tendering procedure has revealed considerable variability in the software itself and the way it is used in its default mode with the potential impact that

P265 SWD data migration with regularization of illumination in the angle domain. Abstract 1 Kirchhoff depth migration is generally regarded as a powerful method of imaging 3D prestack surface seismic data. Recently more effort has been devoted to adapting Kirchhoff depth migration to SWD data. This kind of acquisition frequently contains a limited number of sources and receivers. This produces an irregular illumination of the subsurface and very strong migration artifacts will appear when using the common migration procedure for such data. We describe an approach of true amplitude Kirchhoff migration in scattering angle based on a multi-angle regularization of

P267 WAVE-EQUATION IMAGING IN THE NORTH SEA Abstract 1 Wave-equation migration (WEM) has been shown to produce an improved image over Kirchhoff migration in sub-salt areas of the Gulf of Mexico (Sun et al 2001). However it has not yet been shown to be of benefit in the North Sea. Using generic models of the North Sea this paper examines if WEM can provide a substantial advantage for imaging hydrocarbon reservoirs. We show that the North Sea places demands upon imaging algorithms that standard Kirchhoff migration cannot fulfill in complex geology. Introduction The Kirchhoff algorithm is a standard tool for

P271 WELL LOCATION OPTIMISATION THROUGH USE OF SEISMIC ATTRIBUTES ON THE BRITANNIA FIELD UK NORTH SEA Summary 1 Britannia field seismic attributes now allow better well placement through improved reservoir characterisation and identification of drilling hazards. This is mainly due to greatly improved seismic data quality through the reprocessing of an old survey and the acquisition of a new one. In addition reservoir property prediction through use of seismic attributes has the potential to yield a significant number of new well locations in various areas of the field. Prediction accuracy will be put to the test with a well to

P274 DETERMINATION OF PREVIOUSLY UNKNOWN RESERVOIR STATIC HETEROGENEITY USING WELL DYNAMIC DATA Summary 1 Static heterogeneity that impacts reservoir production is often not completely detectable by seismic or geological methods for reasons of scale specially. Fortunately main heterogeneity can be derived from production performance data once they have been associated with an (iterative) data synthesis which includes all available geological geophysical reservoir pressure and well data. A detailed fast track statistical analysis of production and static data with the spirit of data mining allows the characterization of production-impacting reservoir features. Previously partly unknown heterogeneity is often evidenced in this way.

P276 LOW RESISTIVITY – STRUCTURAL CLAY RESERVOIRS: CASE STUDY IN THE OFFSHORE TEEKIT FIELD ABSTRACT Summary 1 The Teekit Field is located offshore in Mexican territorial waters of the Gulf of Mexico. The main reservoirs are made up of Tertiary arkosic sandstones and are found at a depth varying from 1300 to 2800 meters (4264 to 9184 feet). The reservoirs at the greatest depth have a very complex lithology with a high content of structural clay dispersed clay plagioclases potash feldspars and carbonates. The mineral complexity as well as the high salinity of water in the formation affects the log