Research and Application of Efficiency Improvement for P612 Steam Flooding

Due to factors such as high crude oil viscosity, large well spacing, and strong reservoir heterogeneity, the P612 thermal composite chemical steam flooding has problems such as serious steam channeling and low thermal efficiency. In this study, through two-dimensional visualization experiments, the development law of steam channeling channels is clarified, and the scale of steam channeling channels in P612 well group is calculated using the material conservation method. Based on this, the mechanism analysis of improving injection and production parameters, multiple rounds of combined plugging and adjustment, and other processes is carried out. The results can guide the implementation of steam drive efficiency improvement measures. The research shows that different levels of flow channels will inevitably be formed during steam flooding of ultra-heavy oil. The radius of the pseudo steam channeling channel between X121 and X122 is about 1.753 m, which is much smaller than the well spacing of 140 m. After the formation of main flow channels, the development of secondary flow channels is limited. Improving injection or production parameters and multiple rounds of combined plugging can effectively improve the steam absorption profile and increase the degree of utilization of secondary flow channels. However, for the plugging and adjustment of ultra-heavy oil reservoirs, the effective time has a lag, and the wellhead temperature shows a trend of falling and rising. Through the superposition of two efficiency improvement measures, the daily oil output of a single well in the well group of P612 steam flooding was increased from 1.4 t/d to 1.9 t/d. The results have deepened the understanding of steam flooding for ultra heavy oil, and can provide some reference and guidance for the development of steam flooding in other similar reservoirs.