The role and importance of oil and gas reservoirs in the Clean Energy project

The significant increase in the price of European CO2 emission allowances is an important factor of the currently rapid increase in electricity costs in Poland. One of the ways to reduce CO2 emissions to the atmosphere by the Power Industry in Poland may be the method recommended in the document of the Ministry of Energy, Innovation for Energy - directions of energy innovation development 2017 [9], where it is stated that the development of CO2 capture and utilization technology - CCU (Carbon Capture and Utilization) is desirable. In many countries [7, 8], it has been shown that the technology of CO2 injection into oil and gas reservoirs is a mature technology that could be one of the significant opportunities for CO2 utilization in the processes of oil and gas recovery. Also in Poland, during the last twenty years, two small acid gas injection installations have been implemented into the gas and oil reservoirs, admittedly small, but they have shown the potential for technical possibilities in this respect in our industry. The presented article discusses the research results obtained as part of a project implemented by the consortium of Oil and Gas Institute and Polish Geological Institute - National Research Institutes and commissioned by the Ministry of Environment [6], in which the first methodical assessment of potential additional oil and gas recovery was carried out in CO2-EOR/EGR processes, (Enhanced Oil, Gas Recovery). For the selected 6 oil and 4 gas reservoirs, the most prospective from the point of view of CO2-EOR/EGR technology in the land area of Poland, geological and reservoirs analyzes, computer and laboratory simulations as well as preliminary analysis of the economic effectiveness were carried out. The calculations show a relatively small increase of gas recovery. In the case of oil reservoirs, the effects of the EOR method discussed here are much higher, and the increase in the recovery of resources on average exceeds 30%. These results for subsequent reservoirs are strongly diversified due to the current level of depletion, the nature of the method (secondary or third), energy mechanisms (water activity flowing into the reservoirs) and other reservoir and drilling factors (density of well grid). A quantitative assessment of CO2 sequestration capacity in 10 selected oil and gas reservoirs was also performed. The sequestration was carried out as part of extended enhanced oil/gas recovery by CO2 injection. Preliminary analysis of economic viability were made for two variants of adopted scenarios differentiating the costs of CO2 supply, based on material models, simulation results and the history and forecasts of the exploitation of reservoirs. It has been shown that the use of CO2 in EOR projects to increase the recovery from discovered and developed reservoirs, especially of oil, could be in the near future one of the most significant areas of Polish oil exploitation, allowing to obtain additional significant amounts of crude oil recovery and additional profits from trading in CO2 emission allowances.