Asphaltene Testing for Inhibitor Evaluation

Abstract

Asphaltenes are a global flow assurance problem responsible for reduced production and increased operating costs in many oilfields. Asphaltene inhibitor programs are needed to manage problems and increase operational profitability. Improvements are needed in both developing new inhibitors with better performance and in the understanding and application of testing methods used for evaluating inhibitors. This paper discusses ongoing efforts to improve our understanding of asphaltene deposition and inhibitor testing with a goal to be able to correlate testing results to satisfactorily predict asphaltene inhibitor field performance before application. Three different asphaltene test methods used in our laboratory are presented. The methods include both live and dead crude oil testing. Results from testing with each method and their relevance to field conditions are discussed. More focus is given on the dead-oil testing methods though as live-fluid testing, being more difficult and costly, is not an option for many field studies. Fundamental deposition studies are shown from one of these methods, highlighting the effect of varying different test conditions on deposition. Finally, a case history of a successful asphaltene inhibitor field application is included at the end of the paper. It is included to provide an example of the benefits of an effective asphaltene inhibitor application and show some comparisons between laboratory testing and field experience.