ABSTRACT

This chapter presents 10 case studies where the knowledge gained in previous chapters is applied to understand, predict, or mitigate asphaltene-deposition problems in the field. The chapter is broadly divided into three sections: asphaltene precipitation (six case studies), asphaltene deposition (three case studies), and asphaltene mitigation strategies (case case study). This is a brief description of each case study: (1) Application of the indirect method to screen asphaltene stability problems in the field. (2) Evaluation of potential asphaltene precipitation during enhanced oil recovery (EOR) operation. The effect of gas injection type and amount on asphaltene stability is studied, showing how perturbed chain-statistical association fluid theory (PC-SAFT) can predict whether a specific amount or type of gas can induce asphaltene precipitation. (3) Detection of experimental discrepancies on asphaltene onset and bubble pressures. (4) Investigation of the effect of oil-based mud contamination and commingling of oil on asphaltene stability in crude-oil systems. (5) Modeling of asphaltene polydispersity with a molecular-weight distribution. This case study also highlights the effect of aggregation kinetics on the measured asphaltene onset. (6) Comparison of different thermodynamic models used to predict asphaltene-phase behavior. (7) Application of the asphaltene deposition tool (ADEPT) to forecast the occurrence and the magnitude of asphaltene deposition in Gulf of Mexico wells. (8) Study of corrosion-induced asphaltene precipitation. (9) Investigation of asphaltene deposition in porous media and the effect of asphaltene precipitation and deposition on permeability reduction. (10) Analysis of the poor performance of some asphaltene dispersants to reduce asphaltene deposition.