New approaches to measure heavy oil fluid properties

This SPE paper from the University of Calgary details some new and innovative approaches for PVT measurement in heavy oil.

As we have discussed in may previous articles and posts, understanding the fluid behavior of heavy oils is key for reservoir simulation, making accurate recovery predictions, and optimizing production methods. Typically in heavy oil reservoirs, oil viscosity and density are reliably measured and reported, but more work is needed to better correlate how heavy oil properties change with pressure in establishing accurate PVT relationships required for recovery prediction.

SPE paper 97803, first looks at foamy-oil behavior as a factor for increased production in cold heavy oil reservoirs along with sand production. The idea is to study the bulk fluid properties of live heavy oil prior to sandpack-depletion and then compare that to fluid expansion during pressure depletion in a sandpack to better establish PVT relationships during the cold or primary production phase.

According to the article, X-Ray and computerized assisted technology (CT) scanning can be applied to help measure PVT relationships by looking at images of a pressure vessel filled with live oil; as the volume of the vessel is expanded, bulk densities and free gas saturation can be determined. CT scanning can also help determine where gas is forming in the oil and its effect on oil properties such as viscosity. The paper also describes the effective use of NMR in combination with CT for more accurate viscosity determination in heavy oil.

With new approaches such as the application CT technology combined with more established methods such as NMR, we can further improve our ability to determine heavy oil fluid properties which are in turn key to accurate planning and recovery predictions.

Kambiz.