Innovative approaches to assessing residual oil saturation by the SWCTT method at the Sutorminskoye field

Introduction. Tracer studies (SWCTT) with the injection of surfactant-polymer composition were carried out at a single well of the Sutorminskoye field. The surfactant tested was the enhanced oil recovery agent Sibex Oil & Gas SRF 1000 (Technical Specifications 20.59.59-005-67278822-2025) produced by “ZILANT OIL TECHNOLOGIES” LLC (right holder: SIBUR Holding PJSC).

Aim. Assessment of the efficiency of the newly synthesized surfactant within the surfactant-polymer composition for reducing residual oil saturation and increasing the oil recovery factor.

Materials and methods. The field studies employed a new approach involving the injection of a pre-prepared tracer triplet into a single well, which represents a mixture of a primary tracer, a cover tracer, and a backup tracer. A previously published methodology for determining the well shut-in time (technological settling time for the ester hydrolysis reaction) was successfully tested.

Results. As a result of the surfactant-polymer flooding operations, a reduction in residual oil saturation at the single well was established from 0.233 to 0.116, which corresponds to an increase in the oil recovery factor by 19.1 %.

Conclusion. The data obtained indicate the high efficiency of the newly synthesized surfactant and the viability of the proposed methodological approach using a tracer triplet for monitoring oil displacement processes.

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