(194a) A New Asphaltene Test Under High Temperature and High Pressure – Asphaltene Rocking Cell

The most widely used asphaltene tests in the laboratory are based on solubility and precipitation. Those methods such as Turbiscan and Asphaltene Dispersant Test (ADT) have limitations in operating at high temperature, high pressure and under water incorporated conditions. These limitations might lead to unrealistic interpretation of asphaltene behavior and optimal chemical selections.

Nalco Champion has developed a new method of asphaltene testing which accommodates high temperature and high pressure conditions. This Asphaltene Rocking Cell (ARC) test is analogous of the well-known Hydrate Rocking Cell test but able to operate in high temperature and high pressure (HT/HP) conditions, up to 15,000psi and 250^oF. ARC provides pseudo-live oil condition by combining synthetic field gas with dead crude oil in HT/HP conditions then asphaltene destabilization is demonstrated via depressurization. This enables understanding for asphaltene behavior and the assessment of chemical performances under field conditions. ARC test can be operated in various conditions not only in HT/HP but also in various Gas to Oil Ratios (GOR), different water-cuts and brine compositions. ARC also has advantage on asphaltene testing in CO₂ flood field sample. Nalco Champion has successfully utilized ARC in several case studies from Gulf of Mexico assets and on-shore CO₂ flood assets to deliver best chemical solutions for asphaltene problems which were difficult to achieve by conventional asphaltene testing methods.

In this paper, we will discuss about the ARC test method development and provide case histories of successes of utilizing ARC.