Publications

When steam is present with oil and water in a steam flooded reservoir, calculated two-phase oil saturations from Carbon/Oxygen (C/O) logs are optimistic. Steam saturation may be calculated by acquiring a measurement of the macroscopic capture cross section Sigma. Combining with the C/O log, a three-phase (steam/oil/water) saturation algorithm is applied. The results of the three-phase oil saturation calculation are validated against open hole saturation and core measurements from recently drilled infill wells.This paper presents the methodology to calculate three-phase oil saturation by combining Sigma and C/O logs. A case study is used to document how the results of three-phase oil saturation combined with temperature surveys and pulsed neutron capture (PNC) logs were applied to identify and monitor reservoir depletion, support heat management review, influence steam injection strategy (put the right amount of steam at the right places at the right time, minimize the excessive steam in mature zones, increase steam in immature zones), and identify by-passed oil for increased production. Those efforts result in 9,231 BSPD steam reduction without significant production lost and save more than US$ 3 MM of fuel cost.