TECHNOLOGICAL COMPLICATIONS (FORMATION DAMAGE) DURING CO2 INJECTION FOR ENHANCED OIL RECOVERY. PART 3. PREVENTING AND REPAIRING FORMATION DAMAGE CAUSED BY CO2 INJECTION

The article considers technological complications arising during CO2 injection for enhanced oil recovery, with a focus on the formation of asphaltenes in the pore space and their negative impact on production efficiency. Formation of asphaltene solids in the reservoir leads to an increase in the skin factor, their removal to the wells, accumulation in the wellbore and on the surface of the equipment, which reduces oil flow to the well and requires expensive remedial work. Methods of identification and monitoring of asphaltene deposits are considered. Results of laboratory studies confirming the difficulty of quantitative assessment of asphaltene deposition are given, as well as practical examples of application of various technologies for their prevention and removal. Methods including the use of inhibitors and dispersants and the use of aromatic solvents to restore reservoir properties are reviewed. It also emphasises the need for continuous monitoring of field operations and the development of effective asphaltene management methods, which is critical to improving the economic feasibility of CO2 injection projects.