Serbian Oil Industry (NIS) seeks to boost output from the Country's Largest Oil Field

The objective is to increase oil production at Serbia’s largest oil deposit, the Velebit exploitation field (EP).

Located in the municipality of Kanjiža, the Velebit oil and gas field was discovered in 1968, with commercial production starting in 1985.

According to the request submitted by NIS to the Provincial Secretariat for Urban Planning and Environmental Protection in April, the proposed method involves injecting a surfactant–polymer (SP) mixture into three newly drilled injection wells. The anticipated outcome is increased output from seven reactive production wells.

The SP technique is a sophisticated enhanced oil recovery (EOR) method commonly used in mature oil fields. Surfactants (surface-active agents) reduce the interfacial tension between oil and water, allowing oil to flow more freely from the rock pores. Polymers, on the other hand, increase the viscosity of the injected water, thereby improving sweep efficiency by uniformly displacing oil and minimizing the so-called “water breakthrough” effect.

The goal of the project is to recover oil that would otherwise remain trapped in the reservoir after conventional waterflooding.

According to the environmental impact assessment scoping request submitted by NIS, and subsequently approved by the Secretariat, current daily production at the Velebit field stands at 592 tons of oil, with a water content of 85%, and 15,497 cubic meters of dissolved gas.

The initiative is structured in two phases:

• Phase One (until December 2026): Focused on determining optimal injection parameters for the SP mixture.
• Phase Two (running through 2041): Aims to increase the oil recovery factor by 7.5%, resulting in a measurable rise in oil production.