Asphaltene deposition is a flow assurance problem that threatens the continuous production of crude oil. This problem is likely to get worse because of the current tendency to produce from deeper waters and also due to the implementation of enhanced oil recovery operations based on miscible injection of CO2 or hydrocarbon gas.
In this article we present a review of the asphaltene precipitation and deposition problem in oil production, and we describe the commercial techniques used for its determination and quantification as well as their limitations. We also discuss the important progress achieved concerning modeling tools with enhanced capabilities that have been developed to forecast the occurrence and the magnitude of this problem. Prompt recognition of potential asphaltene deposition issues, either for new fields or as part of enhanced oil recovery projects, is necessary to implement successful prevention or mitigation strategies. Unfortunately, current commercial inhibitors have mixed results in the field and in some cases are responsible for worsening the deposition problem. After a thorough investigation we have elucidated a multi-step mechanism of asphaltene precipitation, aggregation and aging, which explains the poor performance of some chemicals and the limited capabilities of the current testing protocols. We provide some ideas for a new generation of asphaltene inhibitors and, for the cases in which asphaltene deposition has already occurred, we also provide a list of common techniques and best practices used for its remediation.
With this work we aim to provide the reader with a broad understanding of this complex problem and to offer a starting point for the development of cost/effective strategies to manage asphaltene deposition in increasingly complex environments.