Oil Production Enhancement by EOR Candidates Optimization

The study field is located in the Nizhnevartovsk district of the Khanty-Mansi autonomous region. The deposit is located in the Nizhnevartovsk crest zone. The geological section of this deposit features a thick layer (2740-2870 meters) of Meso-Cenozoic era sedimentary rocks starting from the Jurassic period up to and including the Quaternary period, and rests unconformably on the surface of the deposits of the folded Paleozoic basement. The pay zones of study oil and gas fields features mainly sandstone-siltstone reservoirs. The study formation XX11-2 features interleaved rocks with a high clay content. In the west and south-west of the field, the oil-saturated thicknesses vary on average from 5-10 m, and in the north, the thickness increases to 10-20 m. This field has a long-lasting production history as a result of drilling vertical and horizontal wells but is currently at production decline stage. The existing reservoir pressure support system assumes that the water-cut trend at the wells will increase. In recent years, there has been advanced flooding in some areas, resulting in a drop in oil production, while the reasons for the advanced flooding are not always clear. This is often due to the progressing spontaneous fracturing in the injector wells (Aslanyan, Akimov et al., 2020).