64th EAGE Conference & Exhibition

Anisotropic prestack depth migration (PSDM) has clear benefits for imaging purposes in
many areas. An additional benefit of the anisotropic imaging is that the velocity field derived
for migration ties closely to vertical well velocities. It is therefore possible that this velocity
field contains more accurate information than an isotropically derived field and, consequently,
gives better constraints on amplitude inversion of the seismic data.

1002 DELTAIC SANDBODY CONNECTIVITY - SEQUENCE STRATIGRAPHIC-BASED INSIGHTS FROM 3-D RESERVOIR MODELING STUDIES SUNRISE-TROUBADOUR FIELDS AUSTRALIA 1 The Sunrise-Troubadour Fields represent a 16.7 Tcf gas-condensate resource located in the Timor Sea 450 km to the northwest of Darwin Australia. The Middle Jurassic reservoir succession is relatively thin (80 m) but laterally extensive with a combined area of closure of over 1000 square kilometers. One of the major subsurface uncertainties in the evaluation of these fields is reservoir connectivity due to sandbody geometry and post-depositional faulting. This study addresses these connectivity uncertainties via a sequence stratigraphic-based 3-D reservoir modeling approach. The

1004 FRONTIER EXPLORATION ON THE ABYSSAL PLAIN OF THE DEEPWATER GULF OF MEXICO - SYN-RIFT THROUGH PASSIVE STAGE MESOZOIC OBJECTIVES IDENTIFIED 1 MICHAEL J. ROBERTS and SEAMUS G. REILLY Chevron North America Exploration and Production Co 935 Gravier Street New Orleans LA 70112 USA The abyssal plain of the Gulf Of Mexico (GOM) defined here as areas basinward of the Mississippi Fan and Perdido Foldbelts has been described as a featureless plain devoid of significant structuring and underlain by oceanic crust. A regional examination of the province cast doubt on this benign history and revealed a complex structural province with

1006 50 YEARS HENCE - EVOLVING TECHNOLOGIES AND OPPORTUNITIES IN CARBONATE SYSTEMS 1 Carbonate reservoirs are famous for their prolific reserves and infamous for their complexity and unpredictable behavior. Yet it is precisely this combination of vast promise and challenging technical frontiers that ensures that carbonate hydrocarbon reservoirs will form the cornerstone of global energy supply for the next half-century. The vast resource still remaining in giant carbonate oil fields in the Middle East the Caspian region the Cretaceous of Latin America the Atlantic and Caribbean provides substantial motivation for a renewed focused R&D effort in carbonate exploration and exploitation

1008 A STRATEGY FOR AUTOMATICALLY MODELLING EXTENSIONAL SEDIMENTARY BASINS 1 NICHOLAS J WHITE 1 DETLEF HANNE 1 and PAUL BELLINGHAM 2 1 Earth Sciences University of Cambridge Bullard Laboratories Madingley Rise Madingley Road Cambridge CB3 0EZ UK A two-dimensional inverse model for extracting the spatial and temporal variation of strain rate from extensional sedimentary basins is described. Our starting point is a forward model which allows basin stratigraphy to be calculated from any given strain rate distribution. This forward model includes potentially important effects such as flexural rigidity and the twodimensional conduction/advection of heat. Conversely inverse modelling determines strain rate

A-01 IMPROVED SEISMIC RESOLUTION THROUGH FINE SPATIAL SAMPLING - A 2D EXAMPLE ONSHORE ABU DHABI Abstract 1 During the late 1990's efforts were made by the Abu Dhabi Company for Onshore Operations (ADCO) in co-operation with WesternGeco to improve 3D seismic data quality by redistributing the source point energy over a finer spatial sampling of source points in the cross line direction. With the success of this approach and better understanding of the source-related issues consideration was given to optimization of the 3D receiver configuration. The receiver array pattern used for 3D surveys had been derived from earlier empirical 2D

A-03 SIX-FOLD SIMULTANEOUS VIBRATORY RECORDING EXPERIMENT Abstract 1 In order to reduce the size of the source array and ultimately achieve point source in Vibroseis™ acquisition without degrading signal to noise ratio or increasing costs high-fold simultaneous acquisition must be used. Several techniques are already known but not commonly used. An experiment of multi-source acquisition was conducted in Argentina to compare different techniques. Introduction Reducing the size of the source array leads to a reduction in the energy of the source. The implications of this reduction on the signal-to-noise ratio can be evaluated using the square root theory. A widely

A-05 LOW FREQUENCY SUB-BASALT IMAGING Summary 1 Ocean margin basalts are extremely heterogeneous and scatter the seismic energy of the conventional seismic reflection system. To observe sub-basalt reflections the system should be modified to emphasize the low frequencies using much larger air guns and towing the source and receivers at about 20 m depth. The rationale for this approach is supported by synthetic seismograms over a realistic 1-D earth model. In the summer of 2001 we obtained data over basalt in the North-East Atlantic using a system modified to incorporate these ideas. Introduction ANTON ZIOLKOWSKI 1 PETER HANSSEN 2 ROBERT

A-07 SEA SURFACE SHAPE DERIVATION ABOVE THE SEISMIC STREAMER E. KRAGH 1 R. LAWS 1 and L. COMBEE 2 1 1 Schlumberger Cambridge Research High Cross Madingley Road Cambridge CB3 OEL UK Summary: In this paper we show a method of deriving the shape of the time-variant sea surface above the seismic streamer. We record very low-frequency single-sensor data below 0.5 Hz using seismic hydrophones. We then invert the resulting pressure variations to give the wave heights and streamer displacement as functions of position and time. The concurrent recording of the conventional seismic data is unaffected by this method. The

A-09 IMAGING THROUGH GAS CLOUDS - A CASE HISTORY FROM THE GULF OF MEXICO Summary 1 Results from the worlds largest 3D four component OBC seismic survey will be presented. Located in the West Cameron area offshore Gulf of Mexico the survey operation totaled over 1000 square kilometers and covered more than 46 OCS blocks. The area contains numerous gas invaded zones and shallow gas anomalies that disturb the image on conventional 3D seismic which only records compressional data. Converted shear wave data allows images to be obtained that are unobstructed by the gas and/or fluids. This reduces the risk