Use of Partitioning Tracers To Estimate Oil-Saturation Distribution
Partitioning interwell tracer tests (PITTs) have been used to estimate remaining oil saturations (ROSs) during waterflooding.
Partitioning interwell tracer tests (PITTs) have been used to estimate remaining oil saturations (ROSs) during waterflooding. Compared with core tests, well logs, and single-well tracer tests, PITTs sample a much larger representative elemental volume (REV) and provide interwell estimates of remaining oil saturation. In this paper, the authors present the information gained from conducting a polymer PITT and the saturation estimated during the PITT. The polymer PITT allows characterization of polymer-flood efficiency and is a useful tool in polymer-flood evaluations in heterogeneous reservoirs.
The difference in arrival time between conservative tracers has long been used to estimate the volume of oil remaining in a reservoir after tracer tests. The method-of-moments solution to calculate ROS from mean arrival times of conservative and partitioning tracers is based upon single-phase flow.