Jock Drummond

Seismic reservoir characterization of a U.S. Midcontinent fluvial system using rock physics, poststack seismic attributes, and neural networks

In a U.S. Midcontinent gas field, a channel feature contained shale and reservoir sands ranging in porosity from 6% to 20%. Well logs, core data, and 3D seismic data were combined in a reservoir characterization study to map the lithology and variability of porosity within the target sand. The project was conducted in two phases—a qualitative, uncalibrated seismic attribute study and a detailed well-log-calibrated reservoir characterization.

3-D Subsalt Wave-Equation Depth Imaging: A Case Study From The Hickory Field

Summary Subsalt exploration in the Gulf of Mexico has been made feasible in large part by advances in depth imaging technology, leading to several commercial discoveries. These successes, and a new generation of high-powered massively parallel computers, are now leading to the next wave of depth imaging technologies based on full wavefield prestack depth migration. This paper presents the first published case study of 3-D wave-equation imaging in a subsalt setting, based on the Hickory Field in the Gulf of Mexico. The results demonstrate that the technique is now practical and illustrates the potential advantages that can be gained with a shot domain acoustic wave-equation imaging solution.

Adapting to noisy 3-D data: Enhancing Algerian giant field development through strategic planning of 3-D seismic in Berkine Basin

In 1995, after several successful exploration wells, Anadarko Algeria Corporation and partners (Sonatrach, Lasmo Oil Algeria, and Maersk Olie Algeriet) sought to accelerate development in Berkine Basin (Figure 1) where they had rights to five million acres.

Optimizing 3-D seismic technologies to accelerate field development in the Berkine Basin, Algeria

Abstract A radical approach to 3-D acquisition in country with large sand dunes was developed to improve seismic data quality. A methodology was devised which allowed accurate removal of near-surface statics and transmission effects giving enhanced depth prognosis. An adaptive noise-attenuation technique, based upon an image-processing procedure, was developed to improve the signal-to-noise ratio of 3-D data that were contaminated with ‘acquisition footprint’. Finally, parallel survey geometries were devised that reduced the noise contamination of the next generation of 3-D surveys in the Berkine Basin. Most of the 3-D surveys acquired in the Berkine Basin are now designed with parallel templates rather than cross-spreads. This survey technique has been shown to provide better spatially sampled data, despite the interference caused by the huge sand dunes, which, in turn, respond more positively to standard pre-stack noise-attenuation processing. Attribute and coherency analysis, as well as stratigraphic interpretation, is now possible on these datasets with a much greater degree of confidence.

Seismic reservoir characterization of a mid-continent fluvial system using rock physics, poststack seismic attributes and neural networks; a case history

Rock Solid Images 2600 S. Gessner, Suite 650 Houston TX 77063 713.783.5593, Fax 713.783.5594 www.rocksolidimages.com Seismic reservoir characterization of a mid-continent fluvial system using rock physics, poststack seismic attributes and neural networks; a case history Joel D. Walls*, M. Turhan Taner, Gareth Taylor, Maggie Smith, Matthew Carr, Naum Derzhi Rock Solid Images, Houston, TX Jock Drummond, Donn McGuire, Stan Morris, John Bregar, James Lakings Anadarko Petroleum Corporation

Integrated seismic illumination and gravity modeling in refinement of a subsalt interpretation

Summary Top salt geometry exerts a strong effect on the illumination of both the base salt and on underlying subsalt reflectors. A 3D seismic illumination study can be useful for the interpretation of these events. It may also distinguish subsalt amplitude anomalies due to rock property changes (hydrocarbon saturation for example) from amplitude anomalies due to illumination differences. A 3D illumination study was carried out to assess the significance of an apparent bright spot on a key subsalt mapping horizon. The study indicated that the anomaly in question was probably not due to focusing effects. The illumination results also provided evidence for the existence of a salt root coinciding with the sudden disappearance of the base salt reflection event. The presence of the salt root is further supported by the results of a gravity modeling study.

Interpretation of Sub-Salt Converted Waves

Summary Despite improvements in 3-D imaging capabilities through the use of Pre-stack Depth Migration (PreSDM), interpretation of the resultant images in the areas of complex salt bodies is confused by additional events that are not primary PP reflections. This paper analyzes the results of seismic imaging underneath steeply dipping salt flanks using real and synthetic datasets. Based on real data problems, imaging of acoustic and elastic synthetic data sets show that some of the sub-salt sedimentary section may include converted waves. A practical way to correctly image these sub-salt converted waves is introduced.