On the Development of an Asphaltene Deposition Simulator

Abstract

The potential problem of asphaltene deposition during oil production has motivated the development of several experimental techniques and theoretical models to understand and predict asphaltene behavior. Although important progress has been made in this area, prediction of the rate of asphaltene deposition remains an unsolved problem. We have previously reported the successful application of the perturbed chain version of the statistical associating fluid theory equation of state (PC-SAFT EOS) in modeling asphaltene phase behavior under both ambient and reservoir conditions. In this work, we present the development of a simulation tool that simultaneously accounts for asphaltene precipitation, aggregation, and deposition. The thermodynamic modeling using the PC-SAFT EOS is coupled with kinetic models and transport equations. The mechanism for asphaltene precipitation and deposition, proposed in this work, has been found to be consistent with various experiments and field observations. Furthermore, it also provides an explanation to some paradoxes, such as why some asphaltene precipitation inhibitors worsen asphaltene deposition or why strong asphaltene precipitants, such as propane, produce less amount of deposit. The creation of this asphaltene deposition simulator is a significant advance for understanding and predicting asphaltene precipitation and deposition under reservoir conditions.