Determination of minimum miscibility pressure using vanishing interfacial tension in support of Alaska North Slope heavy oil development

Abstract

"Developing Alaskan heavy oils resources has become necessary as, the production from light oil fields in Alaska's North Slope (ANS) is on the decline. Due to the extremely viscous nature of these heavy oils, they are hard to produce by natural pressure. Miscible gas injection Enhanced Oil Recovery (EOR) can be one of the methods for production of these heavy oils. Minimum miscibility pressure (MMP) is an important optimization parameter for EOR processes involving CO₂ or hydrocarbon gas injection. The MMP for a gas-oil system is directly related to the interfacial tension between the injected gas and the reservoir crude oil. In this study, a new technique called Vanishing Interfacial Tension (VIT) was used to measure MMP at reservoir conditions. Experiments were conducted using various gas-oil systems to determine the MMP. The experimental results were modeled using the Peng-Robinson Equation-of-State (EOS) with a commercial simulator (CMG). The Peng-Robinson EOS was tuned with experimental data to predict the MMP accurately. This study has demonstrated the accuracy of the VIT technique in predicting MMP by pendant drop method experiments and simulations using CMG software."--Leaf iii