Single-Well Chemical Tracer Test Experience in the Gulf of Guinea to Determine Remaining Oil Saturation

The Single Well Tracer Test (SWTT) method has proved to be a reliable technique to measure Remaining Oil saturations<br>(ROS) consistently. The technique is based on the chromatographic separation of two tracers, a tracer that partitions into the<br>oil and that hydrolyses in the reservoir, to generate the second tracer, which remains exclusively in the water. Both tracers<br>are produced through the same well in an interval of a few days and the ROS is determined by means of the difference in<br>their arrival times at the wellhead.