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Asphaltene deposition is a long-standing problem that threatens the uninterrupted production of crude oil. Unlike other flow assurance problems, downhole asphaltene deposition is not well-understood partly as a result of the complexity and diversity of the asphaltene chemical structure. Continuous downhole asphaltene inhibitor injection is one of the preventive strategies used to mitigate the asphaltene deposition problem. Such chemicals that are injected in low dosage are screened in the laboratory before field implementation. Over the last 20 years, various asphaltene testing methods have been proposed for product selection and research and development. Still, the lack of lab to field correlation remains a challenge for the operators, service providers, and chemical companies. Therefore, the search for robust, rapid, and reproducible lab screening methods for asphaltene inhibitors is ongoing. This review summarizes lab evaluation techniques adopted by different researchers, their governing principles, and the pros and cons. It may serve as a guide for adopting appropriate strategies and pursuing further investigations on the lessons learned. The hope is that, with a more in-depth understanding of the current methodologies, a better workflow can be designed to select the proper asphaltene control products for field implementation.

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The design of new and improved catalysts is an exciting field and is being constantly improved for the development of economically, highly efficient material and for the possible replacement of platinum (Pt)-based catalysts. In this, carbon-based materials play a pivotal role due to their easy availability and environment friendliness. Herein, we report a simple technique to synthesize layered, nitrogendoped, porous carbon and activated carbons from an abundant petroleum asphaltene. The derived nitrogen-doped carbons were found to possess a graphene-like nanosheet (N-GNS) texture with a significant percentage of nitrogen embedded into the porous carbon skeleton. On the other hand, the activated porous carbon displayed a surface area (SA) of 2824 m 2 /g, which is significantly higher when compared to the nitrogen-doped carbons (SA of ∼243 m 2 /g). However, the nonactivated N-GNS were considered as an attractive candidate due to their high electrochemical active surface area, the presence of a mixture of porous structures, uniform layers, and effective doping of nitrogen atoms within the carbon matrix. Importantly, the hydrogen evolution reaction activity of the derived N-GNS sample illustrates a significant catalytic performance when compared to that of other nonfunctionalized carbons. Our current finding demonstrates the possibility of converting the asphaltene wastes into a highvalue-functionalized porous carbon for catalytic applications.

Asphaltene deposition is an increasing problem in many oil fields around the world. One of the most common strategies to mitigate asphaltene deposition is based on the continuous injection of asphaltene inhibitors. These chemicals are usually screened in the laboratory following one or more of the many techniques available to evaluate their performance, such as precipitation tests or deposition tendencies, using various setups, such as a Taylor–Couette cell, flow loop, capillary tube, or packed-bed column. The performance ranking of chemicals for a given crude oil sample depends upon the type of test used. There are cases where chemicals that perform well in the laboratory are not as effective in the field, as a lab to field correlation for asphaltene inhibitor screening is still being developed. In this work, we investigate the case of a commercial asphaltene inhibitor that shows adequate performance in a deepwater–oil well. We analyze its behavior in the laboratory using a series of tests on treated and untreated oil samples collected from the field. Depostion behavior of model oils prepared from the deposits retrieved from this field has also been studied. Moreover, we have put special attention on the effect of asphaltene polydispersity on the performance of the chemical and track the performance of the product over a period of several years. The results and analyses presented in this work aim to expand our knowledge on this topic and provide some best practices for testing the performance of asphaltene inhibitors in the laboratory, with the ultimate objective of establishing a series of laboratory tests and a workflow to correlate laboratory and field performance of these chemicals.