S. Narayan et Mb. Dusseault, Sensitivity studies of resistivity monitoring for shallow enhanced recovery processes - A numerical case history, J CAN PET T, 39(2), 2000, pp. 52-61
Enhanced Oil Recovery (EOR) processes have been monitored using gas analysi
s, geophysical logging, observation wells (pressure and temperature), well
testing methods, seismic velocity tomography, and inversion of deformation
measurements. Each of these methods has various strengths and weaknesses. M
ost EOR processes involve large changes in the formation resistivity becaus
e of the introduction of a fluid phase with a different electrical conducti
vity, or because of a large temperature change. These massive changes in su
bsurface conductivity may be monitored remotely using subsurface-to-surface
resistivity techniques to investigate propagation of fluid fronts and grow
th of affected zones with time. In this paper, we present general requireme
nts for resistivity techniques in EOR monitoring, typical electrode install
ations to reduce noise and seasonal variations, and approaches to the inver
sion of three-dimensional (3D) EOR resistivity problems. Sensitivity analys
es for a real reservoir case subjected to EOR are presented, and a method o
f rapid design evaluation for resistivity monitoring is outlined. It appear
s that that the analysis tools and the technology is now adequate to system
atically develop electrical monitoring for various EOR applications.