Physical simulation experiment of tuffaceous dissolution effect in sandstone reservoirs: a case study of Paleogene Wenchang Formation in Huizhou and Lufeng area, Pearl River Mouth Basin

Tuffaceous sandstone reservoirs of Paleogene Wenchang Formation in Huizhou and Lufeng area of Zhu I Depression, Pearl River Mouth Basin were selected, and core-scale fluid-rock interaction simulation experiments were designed and carried out to explore the dissolution and modification effect of acidic fluid on tuffaceous components in clastic reservoirs during burial process and its controlling factors. The dissolution characteristics and physical property response characteristics of sandstone reservoirs under different fluid flow rates and tuffaceous contents before and after the experiments were compared and analyzed through microscope observation, fluid composition analysis, physical property characterization and other methods. The results showed that tuffaceous dissolution was common in acidic fluid environment, but the intensity of tuffaceous dissolution and the response of reservoir physical properties were different under different experimental conditions. Among them, the openness and closure of diagen