Kinetic aquathermolysis tested on Boca de Jaruco oil samples

To scale, design and optimize oil production, scientists from Kazan Federal University together with Zarubezhneft were the first to develop a kinetic model of catalytic aquathermolysis using a water-soluble nickel-based catalyst.

The water-soluble catalysts demonstrate efficiency in reducing the viscosity of bituminous oil and can be used in the field with lower costs. Their application allows to optimize expensive steam-thermal methods of oil recovery enhancement.

In the paper it was shown that the use of nickel sulfate helps to increase the activity in the conversion of heavy fractions and increase the proportion of saturated and aromatic hydrocarbons. The advantage of this system is that it can be injected into the reservoir at a depth of 600-700 meters as an aqueous solution without the use of organic solvents.

"The use of nickel sulfate is economically and technically viable in bituminous oil fields than other some oil-soluble catalysts because it is less expensive to synthesize and inject into wells. In addition, this water-soluble catalyst is considered environmentally friendly, making it an attractive alternative for catalytic aquathermolysis methods," reports José Guillermo Félix Lugo, Research Associate of the In-Situ Combustion Laboratory.

In fact, the scientists proposed a low-cost, easy-to-handle catalyst.

"Nickel sulfuric acid gives a good balance between efficiency and practicality. It promotes the conversion of asphaltenes—the most complex and heavy components of oil—into lighter fractions," explains his colleague Suwaid Muneer Abdo Mohammed.

To scale, design and optimize the promising new technology, a kinetic model was developed that defines the mechanism of chemical reactions to convert some oil fractions into others during catalytic aquathermolysis.

"In the course of joint research with our industrial partner Zarubezhneft, important results were achieved: the proposed model successfully predicts the behavior of fractions (saturated, aromatic, resins and asphaltenes) during the aquathermolysis process using nickel sulfate. The kinetic model helps to understand and optimize the conversion of heavy fractions to lighter fractions, which is crucial to improve the efficiency of the aquathermolysis process. At the same time, the catalyst reduces the activation energy of the conversion of asphaltenes to lighter fractions, which is an important objective in the refining of heavy oil. Nickel sulfate prevents excessive conversion of light fractions into gases, preserving hydrocarbons in the liquid phase, which is very important for the further stage of product preparation," comments Mikhail Varfolomeev, Chair of the Department of Petroleum Engineering.

The technology is planned to be applied at the Boca de Jaruco field in the near future.

"The nickel sulfate catalyst enhances the conversion of asphaltenes into maltene and prevents cracking reactions of light fractions with the formation of gases. This is an advantage for the cyclic steam injection technology used in the Boca de Jaruco field, since it is known that gas production inhibits the growth of the steam chamber, reducing oil recovery, and with the developed catalyst it can be increased," says José Guillermo Félix Lugo.

The Boca de Jaruco field was selected for catalytic aquathermolysis because of the high viscosity of the oil, which presents significant extraction challenges using conventional methods.

"The use of a water-soluble catalyst effectively affects the thermal decomposition of heavy fractions by reducing the viscosity of heavy oil, resulting in a significant increase in its mobility under reservoir conditions, facilitating its recovery and subsequent transportation," said Muneer Suwaid.

The error of the kinetic model did not exceed 6.9 percent, which indicates the high accuracy of the developed process.

More information:
Kinetic model for Boca de Jaruco heavy crude oil catalytic aquathermolysis using NiSO4 catalyst
www.sciencedirect.com/science/ … 0016236124010949?via%3Dihub

Provided by Kazan Federal University