Geophysical Section

Section Head: Yuri V. Ganshin
Email: yganshin@uwyo.edu

Phone: (307) 766-2286 Ext. 251

The Geophysical Section's current activities are twofold:

• geophysical data compilation for the state of Wyoming and
• geophysical support of energy-related industries in Wyoming

In regard to geophysical data compilation, priority is given to seismic 2D and 3D surveys that are processed using commercial and in-house techniques. These techniques include innovative seismic velocity/frequency analyses that are aimed at a better understanding and imaging of the subsurface geology, hydrocarbon resources, and physical features of the State. The Wyoming State Geological Survey welcomes any donated seismic data-sets acquired in Wyoming. These data will be re-processed and re-interpreted using the Section's in-house facilities. The important goal of data compilation for the WSGS is creation of interpreted seismic data catalogues for each of Wyoming's oil/gas producing basins. These catalogues will include 2D sections and 3D volumes with variable seismic attributes. At the locations with well control these attributes will be correlated with geophysical logs. These catalogues will enable explorationists to chose the proper attributes to delineate hydrocarbon reserves with lesser uncertainty.

In regard to geophysical support, the Section responds to all inquiries directed to it, and offers geophysical assistance to the State of Wyoming oil, gas, and coal industries. The WSGS can provide the skills and optimized processing schemes to ensure the best possible basis for successful project management. Some sensitive processing steps can be outlined, or if necessary they can be generated entirely at the WSGS, for example:

• Use of log data to calculate synthetic seismogram to be compared with surface seismic;
• Interpretation of the formation tops in time and depth on the log and seismic data;
• Continuous, high-resolution seismic velocity analysis (2D and 3D);
• 3D seismic attribute analyses (continuity, dip, and azimuth).

SEISMIC ATTRIBUTES

Seismic attributes are the quantities mathematically derived from pre-stack and post-stack seismic data. In many cases they are more closely related to the physical rock properties rather than conventional seismic amplitudes. Properly chosen seismic attributes highlight specific petrophysical/geological parameters like lithology, fluid content, and degree of fracturing. Attribute analysis of 3D seismic data with several types of seismic attributes may reveal geologic factors that control spatial distribution of subsurface energy reserves like in examples shown below.