The Acronym stands for Depressuring the Upper ROZ. We sometimes also refer to the process as Depressuring EOR since what is happening is removal of large volumes of water from the formation which, in turn, allows the gas in solution within the residual oil to expand therefor changing the relative volume of water and oil in the reservoir, The properties of the oil are thus changed like they are in enhanced recovery processes.
For more information, take a look at this presentation.
SAN ANDRES FORMATION RESIDUAL OIL ZONES AND THEIR RELATIONSHIP TO THE HORIZONTAL CARBONATE PLAY ON THE NORTHERN SHELF
L. Stephen Melzer, Melzer Consulting
SIPES # 1081
and Dr. Robert Trentham, UTPB
and with invaluable contributions from
David Vance, Arcadis
April 20, 2016