A practical method for anticipating asphaltene problems

Asphaltenes can separate from some oils during depressurization. In other cases, the addition of lift or injection gas can destabilize asphaltenes. This paper presents an integrated approach to predicting all these potential asphaltene problems. Laboratory characterization of asphaltene stability in stock-tank-oil samples is used in combination with standard pressure/volume/temperature (PVT) and compositional data. Details of the characterization technique and prediction method are provided for problems of practical interest, especially for offshore developments where advance planning is of particular importance for many flow-assurance problems. Predictions of asphaltene stability with this approach are compared with live-oil measurements and field experience, where available.