(414i) Improving the Mobility and Relative Permeability of Tar Bearing Heavy Oil in the Gulf of Suez for Increased Production Using Permeability Viscosity Modifiers

One of the most difficult and problematic productive zones in the Gulf of Suez is a heavy oil zone
containing large concentrations of tar and asphaltene. This research investigates the usage of a relative
permeability modifier that is compatible with both the tar and asphaltene to improve the relative
permeability of the crude oil and reduce its viscosity while avoiding asphaltene precipitation and
formation of asphaltic sludge or emulsions.

Initially, multiple fluid samples were prepared in test tubes and tested. The samples were composed of
10 ml of crude oil and different concentrations of the relative permeability modifier ranging from 0.1 to
5%. The samples were shaken vigorously and then were analyzed for asphaltene precipitation and
emulsion formation. Viscosity of the samples was then measured under different temperature
conditions. Coreflooding tests were then conducted to measure the permeability of the crude oil
samples using the same concentrations of the relative permeability modifier. The effect of varying the
core permeability, porosity, pore volume, and the relative permeability modifier concentration was
tested.

The static crude oil experiments in the test tubes showed that the relative permeability modifier was
highly soluble in the crude oil even at 5% concentration. Also, there was no asphaltene precipitation
which indicates that the relative permeability modifier was compatible with asphaltene. This was
verified using filtration experiments. No emulsion was formed even after vigorous shaking of the test
tubes. The coreflooding experiments showed that the relative permeability modifier was a strong
function of the concentration of the chemical and the permeability of the core. The porosity and pore
volume had no impact on the performance of the relative permeability modifier. Reducing the
permeability of the core sample allowed for the relative permeability modifier to interact with the crude
oil for a longer duration which increased its overall effect. In the higher permeability cores, the crude oil
had a much higher potential to flow and thus the primary effect of the relative permeability modifier
was to reduce the viscosity of the oil. Increasing the concentration of the relative permeability modifier
also increased its impact, however, when the concentration exceeded 3%, the improvement was
minimal.

This research shows the significance of using a low cost highly compatible relative permeability modifier
to increase the relative permeability of heavy oil with a high asphaltene and tar concentration. The
relative permeability modifier managed to improve the relative permeability of the oil significantly and

decreased its viscosity as well. This can help increase the production of this high potential zone in the
Gulf of Suez in Egypt.