Study of the Potential for Future Work on Methods of Determining Residual Oil Saturation. Progress Report, January 1 to April 30, 1978

摘要

Various possibilities for research related to methods for determining residual oil saturation (ROS) are considered. A brief digest of the methods that are preferred by many of the people who have worked on the problem of determining residual oil saturation is presented. Some operators have the opinion that one or more pressure cores should always be taken in any reservoir that is being evaluated for tertiary oil recovery. Other operators do not take such cores, because they consider the cost of pressure coring to be excessive, in view of uncertainties about core recovery and the results obtained from the cores. The logging procedures that are preferred are the nuclear magnetic log (NML) inject-log (in open-hole completions) and the pulsed neutron capture (PNC) log-inject-log (in cased holes). Single-well tracer tests often are run as a check on the results of pressure coring and log-inject-log tests. The tracer results probable are weighted toward the residual oil saturations that exist in the more permeable parts of the reservoir. (ERA citation 04:012352)