Overview
Standard enhanced oil recovery (EOR) and PVT testing programs include experiments, such as solubility/swelling, multi-contact, slim tube, vapor-liquid equilibrium (VLE), and fluid property measurements.
These tests are designed to determine the extent of gas miscibility and mixture phase behavior during gas injection into hydrocarbon reservoirs. While common in conventional reservoirs for decades, EOR programs have also found recent applicability in unconventional plays.
Surface oil and gas samples are captured and recombined to recreate downhole reservoir fluids. Injection gases may be separator or sales gas derived from a nearby installation, or synthetically prepared gas based on a composition provided to our laboratory. Refer to PVT Laboratory Testing – Best Practices.
Data in Context
GeoMark has conducted a multi-client EOR consortia study in the Eagle Ford Shale. The behavior of new systems is compared to the industry trends established by this relevant Eagle Ford study. Contact us to get more information about this study.
FAQ
Q. Will a specified gas be miscible with an oil?
A. This question is answered through a PVT and EOR testing program. Compositional data is combined with EOR tests, like swelling and slim tubes, to determine the miscibility pressure.
Q. What if a reservoir fluid is already saturated (at bubble point)?
A. This is a difficult situation. By definition, the reservoir fluid is already saturated with gas and won’t “accept” any more to change its properties. In such cases, the most applicable test is a multi-contact equilibrium test; whereby, repeated contacts of fresh injection gas are used to vaporize some of the light components of the oil, while also reducing its viscosity.