Research of gas hydrate formation inhibitors continues at KFU

A paper saw light in Chemical Engineering Science.

The latest series of inhibitors developed by scientists of the Institute of Geology and Petroleum Technologies of Kazan Federal University surpasses the most effective foreign analogs in terms of their target properties, and also shows a tendency to biological degradation in offshore conditions.

Today the developed class of hydrate formation inhibitors based on water-soluble polyurethanes is a trademark of the researchers of the Institute. Kazan scientists create multifunctional, effective, safe for humans and the environment reagents, the functionality of which is determined by a single molecule.

"We are conducting systematic research in hydrate technologies, which is aimed at controlling the kinetics of hydrate formation processes of hydrocarbon gases. On the one hand, we are developing chemical reagents – promoters that accelerate hydrate formation in solid gas technology for gas storage and transportation. Another direction is related to the fight against complications caused by hydrate formation at the stages of oil and gas production, gathering and treatment, which can lead to technological stoppages and accidents. These problems are especially acute for offshore fields, where they can lead to environmental pollution and ecological disasters. We have proposed a new solution for inhibitors – the use of water-soluble polyurethanes. By varying their structure, it is possible to obtain very effective multifunctional reagents. This is certainly related to the development of low-tonnage chemistry in our country, because earlier effective kinetic inhibitors of hydrate formation were only produced abroad," explains Chair of the Department of Petroleum Engineering Mikhail Varfolomeev.

By 2024, Kazan University has already produced a wide range of molecules that have been patented. In this new paper, scientists have examined the dependence of the molecules' antihydrate properties on the use of a number of dialkylamine-based monomers. This study demonstrates the manifestation of the best hydrate formation inhibitor properties.

"We have investigated our inhibitors under dynamic and static conditions that simulate different stages of real oil and gas processes, using a specialized oscillating cell setup and differential scanning calorimetry. With the help of our research it was possible to reveal the relationship between the decrease in interfacial tension and the increase in the effectiveness of kinetic inhibitors. This fact further confirms the hypothesis that water-soluble polyurethanes act by adsorption mechanism," says Dmitriy Gnezdilov, Junior Research Associate of the Laboratory of Enhanced Oil Recovery.

"By the supercooling temperature of the hydrate formation process our inhibitors surpass the most well-known foreign reagents, which allows their successful application in harsher conditions. At the same time, studies in the water of the Barents Sea show that they have good biodegradation and are safer than their foreign analogs," adds his colleague Roman Pavelyev.

Further down the road, steps will be taken to optimize the synthesis of the developed compounds while maintaining high target properties. The group will also continue searching for new monomers capable of improving the solubility of polymers in water with different salinity and expanding the functionality of their application.

"The objective is to select an inhibitor not only for production, gathering and transportation of hydrocarbon fluid through pipelines, but also for efficient gas injection to increase oil recovery. Here we have a more difficult task to solve, as the application conditions are more severe due to high pressure and mineralization of formation water," continues Gnezdilov.

It is planned that in the near future the developed inhibitor will be applied to the conditions of offshore fields, including the Arctic shelf, which is promising in terms of new sites with large oil and gas reserves.

The importance of the inhibitor for the domestic economy can hardly be overestimated: more than ever the country is interested in the fact that hydrocarbon production is carried out in an optimal mode for the environment and fully complies with environmental requirements. Thus, the development of Kazan University scientists not only demonstrates readiness for industrial application, but also makes it possible to reconsider the possibilities of oil production in extreme cold.

More information:
Effective prevention of structure II gas hydrate formation using the newly synthesized kinetic inhibitors
www.sciencedirect.com/science/ … 02860?dgcid=coauthor

Provided by Kazan Federal University