Three-Dimensional Imaging of Heat Zones at an Athabasca Tar Sands Thermal Pilot

Norman E. Pullin, Ronald K. Jackson, Robert F. Thorborn, Lennert D. Den Boer, W. Keith Hirshe, Lary W. Matthews

A large portion of the ultimate success of heavy oil in-situ thermal pilots is necessarily related to preliminary knowledge of the reservoir characteristics, along with reliable tracking of the subsequent subsurface heat movement throughout the life of the project. Many recent advancements in seismic technology can be used for remote sensing of these heat zones.

High resolution three-dimensional (3-D) seismic surveys were conducted before and during steam injection at Amoco's (AOSTRA and Petro-Canada) Gregoire Lake In-Situ Steam Pilot (GLISP) located in northeastern Alberta, Canada.

This paper addresses the rock properties studies, seismic modeling, and 3-D seismic imaging of induced heat movement at this pilot.

The monitoring technique used is related to changes in acoustic impedance caused by the heating of tar sands. Rock-property testing of on-site high viscosity tar sands core samples indicated a velocity decrease of up to 30% with increase in temperature. Model studies using these data demonstrate the feasibility of imaging the heat zones with good high-frequency, high S/N seismic field data. Comparison of the 3-D seismic data set after steam injection with a similar data set obtained prior to steaming resulted in excellent imaging of the heat zones.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.