Home ]


SWLGS Luncheon Topics

Updated Dec. 6, 2006

Dec. 2006

Quantitative Integrated Evaluation with Explicit Large Scale Shared Earth Models for Ursa Field



Rocky Detomo, Jr., Exploration Geophysical Consultant, Shell International E & P, Inc., New Orleans, LA.

Bart Tichelaar, Geophysicist, Shell International E & P, Inc., New Orleans, LA.

Abstract Summary


A subtle, sophisticated class of opportunities for which uncertainties must be reduced, drives today’s exploitation of oil and gas in Deepwater.  Today’s explorer is often faced with the issues of seismic imaging, non-amplitude supported oils, stratigraphic uncertainty, and uncertain hydrocarbon kitchens, all in an environment dominated by rising deepwater costs and still-maturing technology.  However, many of the fundamental Exploration processes that drove the industry before the advent of the amplitude play in the Gulf of Mexico, still apply.  Although success rates associated with those early techniques alone are not acceptable in today’s industry, explicit integration of these historically proven processes with each other and with new technologies, driven by a growing body of knowledge within the GOM Deepwater, has provided a significant new methodology for wildcat and near-field Exploration.  Even in mature fields, additional opportunities are seldom characterized by unambiguous attributes of direct hydrocarbon indicators or amplitude support.  Shell’s “Quantitative Integrated Evaluation” process relies upon visualization of integrated volume-based models of texture derived geologic stratigraphy and of predicted rock and fluid properties, represented with corresponding full, 3-D, elastic seismic response forward models, explicitly compared and calibrated to measured elastic seismic attributes.  A “Differential Generalized Attribute”, which summarizes the differences between multiple scenario response predictions and actual measured data, can then be used to estimate the subsurface scenario’s likelihood of occurrence and detectability.  This methodology allows competing scenarios to be rapidly tested against the data, and is built upon proprietary knowledge of the physical processes and relationships that likely drive vertical and lateral variation in these models.  As a demonstration of this methodology, we will show a portion of the Ursa Basin and describe the integrated capability that is emplaced at the Exploration phase, and matured throughout the Appraisal, Development and Production life cycle of a basin discovery.

Biographical Sketch

Dr. Rocky Detomo, Jr. received his B.Sc. and M.Sc. in Physics from The Ohio State University in 1973 and 1975, respectively.  He then served as an Experimental Research Associate at The Ohio State University Van de Graaff Accelerator Laboratory where he received his Ph.D. in Experimental Nuclear Physics in 1981.  Rocky then joined Shell Western E&P as a Geophysicist where he supervised Land Acquisition and Seismic Processing Teams for Shell, and interpreted onshore in Continental and Western United States.  From 1991 until 2005, Rocky had been in New Orleans managing and interpreting for Shell Offshore, Inc & Shell International E&P in the Gulf of Mexico, focusing on structurally complex and technically challenging areas.  He was the lead geophysical interpreter for a number of Shell’s subsalt developments, and recently returned to Houston to work on Global Deep Water Exploration Evaluation & Quantitative Integrated Evaluation Capability Deployment.  He is currently Shell’s Gulf of Mexico Exploration Seismic Manager.  He is the recipient of the Houston Geologic Society 1997 Best Paper of the Year, and the 1997 A.I. Levorsen Award for GCAGS Best Paper.  Rocky is a former President for SGS, the Technical Chairman for the 2006 Annual SEG Convention, and a member of SEG, APS, and Sigma Xi.