Aspects of Rock Physics in 4-D Seismology
Zhijing Wang, Steve Jenkins, Michel Bee, Michael Waite,
Michael Cates, and Robert Langan
In recent years, time-lapse 3-D or 4-D seismology has been used to identify
bypassed oil, to monitor steam and CO2 injection processes, and even
to track the movement of the injected water. However, the feasibility of
applying seismic technology to monitoring
oil recovery processes and the ability
to interpret the seismic results depend to a large extent on the understanding
of the physics or seismic properties of the
reservoir
rocks and fluids.
We have carried out several laboratory rock physics investigations on seismic
properties of reservoir
rocks in relation to oil recovery processes.
Particularly, we found that seismic properties were dramatically affected by the
injected steam in heavy oil sands, by the injected CO2 in carbonate
rocks, and in some cases, by the injected water in light oil
reservoir
sands.
In this paper, we present laboratory results of seismic properties of oil
sands from several places in the world, including Indonesia, Canada, and
California, and of West Texas carbonates
undergoing CO2 injection. We
discuss the effects of
reservoir
geology, fluid properties, and recovery process
on the seismic properties and how the laboratory results can be used in the
feasibility studies and seismic interpretations. We also show examples of 4-D
and cross-well seismic results from the Duri field, Indonesia, and from a West
Texas carbonate field undergoing CO2 flooding.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California