Abstract
A tight conglomerate reservoir is a kind of unconventional reservoir with strong heterogeneity, and CO(2) injection is an economical and environmentally friendly method to enhance tight oil recovery. Supercritical CO(2) is a very promising fluid medium for unconventional reservoir development due to its gas-liquid dual properties. In this study, the production effects of supercritical CO(2) and non-supercritical CO(2) in tight conglomerate reservoirs were quantitatively analyzed by huff and puff simulation experiments conducted under reservoir conditions (formation pressure 37 MPa, temperature 89 °C). Also, the influencing factors of CO(2) huff and puff production, including injection volume, soaking time, and throughput cycles, were investigated. The results showed that supercritical CO(2) improves the recovery by 4.02% compared with non-supercritical CO(2). It could be seen that supercritical CO(2) plays a positive role in improving tight conglomerate reservoirs. The optimal injection volume, soaking time, and throughput cycles were determined to be 0.50 PV, 2 h, and 3 cycles, respectively. This paper provides an important basis for the study of supercritical CO(2) production in tight conglomerate reservoirs.