Effects of Rock Permeability on Capillary Imbibition Oil Recovery from Carbonate Cores


1 Department of Chemical and Petroleum Engineering,Sharif University of Technology

2 Department of Chemistry,Sharif University of Technology


In order to investigate the feasibility and e ects of core permeability on capillary imbibition
recoverable oil from carbonate cores, some laboratory tests were carried out at the EOR research
laboratories of Sharif University, Iran. Outcrop rocks with di erent permeabilities were taken away from a
recognized outcrop and used in these experiments. Special core analysis tests were run on two core samples
to nd out relative permeability and end point saturations. Wellhead separator oil and gas samples were
collected and recombined to a reservoir gas - oil ratio. A core
ooding system with a capability of free and
forced imbibition testing was designed and installed. A number of free and forced imbibition tests with
di erent cores under reservoir conditions were conducted. The results of the tests revealed that capillary
imbibition is an almost fast process at laboratory scale and the higher permeable cores will imbibe more
easily. A good correlation could be obtained when the ratio of recovery factor to ultimate recovery factor
versus a de nite function of time was plotted. From these experiments, it concluded that an up scaled
relation can be perceived for very low permeable cores, the testing of which may take too long.