CO2 huff and puff pilot with staged-fracturing horizontal well in tight oil reservoirs

CO2 huff and puff has been considered as one of the most successful processes to increase oil recovery, however, this stimulation technology is yet to be widely used in tight oil reservoirs. In this paper, a production model is developed to describe the CO2-soak process in tight oil reservoirs, providing a guidance to optimize the production parameters for CO2-soak pilot in the staged-fracturing horizontal well. The result shows that the CO2 huff and puff process helps to improve the reservoir energy, the fluid mobility, and thus the reserves-to-production ratio. To be specific, the recovery factor of tight oil reservoirs stimulated with CO2 huff and puff technology is 2.0% higher than that produced with natural energy. The success in CO2 soak pilot is of importance significance to the effective development of tight oil reservoirs.