Asphaltene Inhibitor Screening of Next Generation: Automated High-Throughput Experimentation Method
Authors: Punase Abhishek Dinesh , Addis Kyle , Robertson Adam , Wylde Jonathan J. 
Published: August 2023

Asphaltene deposition has been a critical flow assurance challenge, and chemical treatment with continuous asphaltene inhibitor injection has been the go-to approach for operators to preemptively tackle this challenge. Development of the right inhibitor chemistry and dosage is challenging and critical. A smart, automated process for screening numerous asphaltene inhibitor formulations based on the design of experiment (DoE) and high-throughput experimentation (HTE) method has been developed and is discussed in this work.

Asphaltene inhibitor formulations with distinct base chemistries, boosters, and solvent packages were blended in various ratios to encompass a large chemical and formulation space with the automated blending station of the HTE setup. These formulations were then dosed into a multitude of crude oil samples produced from different regions of the world at constant dosages to represent a uniform and comparable test fluid matrix. The dispersion state of asphaltene clusters within dosed oil samples, in their native state, was then evaluated using the HTE-asphaltene differential aggregation probe test (ADAPT) techniques to generate thousands of performance data points. Furthermore, the efficiency of top-performing formulations was then cross-validated using standard optical transmittance and deposition-based techniques to gauge performance.

The four main pillars of the HTE technique are automation, miniaturization, parallelization, and computational design. Each of these pillars contributes to enhancing the current test method into a more accurate, agile, and quicker technique. Through automation, the overall accuracy of formulation blending as well as performance efficiency measurement is increased. With miniaturization, the resource consumption of raw materials and more importantly crude oil is considerably reduced. For this work, each formulation required less than 300 µL of oil per measurement. Parallelization resulted in completing the test evaluation at a rate of 600 evaluations every 4 hours. These results can then be analyzed through the computational design and analytics software to identify the top-performing formulations along with predicting the optimal chemical formulation space that can lead to maximum performance efficiency. The selected formulations were subsequently blended on a bigger laboratory scale, and their efficacy was cross-checked with both dispersion- (optical transmittance and thermoelectric methods) and deposition-based (flow loop setup) techniques against a benchmark asphaltene inhibitor product, known to work successfully in many fields having asphaltene instability related issues. Through this process, several new asphaltene inhibitor formulations were discovered that outperformed the benchmark blend.

Automated HTE technology provides a new dimension to asphaltene inhibitor development work that can carry out performance evaluation of numerous formulations at tremendous speed and minimum crude oil volume. With this technique, one can quickly adapt to the changing requirements of asphaltene inhibitor and its dosage with varying crude oil composition, gas/oil ratio, water cut, or any operational change affecting overall asphaltene stability.