Asphaltene Deposition Tool: Field Case Application Protocol

Abstract

Abstract In the petroleum industry, arterial deposition of asphaltenes is one of theissues requiring flow assurance consideration during asset development. As thephysical or chemical conditions inside the reservoir, and hence the wellbore, changes, the originally stable asphaltenes in the oil, can precipitate, potentially leading to deposition in the wellbore. The arterial deposition ofasphalenes then would reduce the production rate of oil. Remediation bysolvent-soaks and squeezes is expensive, on the order of several milliondollars. The economic impact of such deposition must be anticipated and asuitable philosophy for management of these deposits should be developed. A keyitem in the successful management of asphaltene deposition requires reasonableestimation tools regarding the growth rate and location of deposits since thiseffects the gross up time of the production facility being designed. In this work, a simulation tool that can be used to predict the amount ofgrowth rate and location of asphaltene deposits in wellbores / pipelines ispresented. In this asphaltenes deposition simulator, the transport equationsare coupled with kinetic models to describe the precipitation, aggregation, anddeposition of asphaltenes. The phase behavior of asphaltenes in oil isdescribed by using the Perturbed Chain version of Statistical Associating FluidTheory Equation of State (PC-SAFT EOS). In this paper, the protocol that needsto be followed for the application of this deposition simulator to ascertaingrowth rate and location of asphaltenes in field scenarios is presented. Theexperimental methods required to obtain the kinetic model parameters are alsodiscussed. Application of the simulator to study asphaltene deposition in oneof the pipelines in the Gulf of Mexico that has reported asphaltene depositionproblems is also presented.