Study on the Evaluation Method for Water Flooding Characteristics of Horizontal Wells in Thick Oil Reservoir with Bottom Water

Due to the strong heterogeneity of thick oil layer bottom water reservoirs, the production characteristics of each horizontal well vary greatly after entering the high water cut stage, and the judgment of the water flooding degree directly affects the subsequent treatment process of the well. In this paper, through the analysis of the water flooding mechanism, the water flooding mode of horizontal wells with bottom water is improved, the second derivative template of the water cut is innovatively applied, and the semiquantitative judgment of the water yield point and water yield intensity is conducted in two rounds, forming the evaluation method for the water flooding characteristics of horizontal wells in thick oil reservoirs with bottom water. The research results indicate that the main factors affecting the water flooding situation of horizontal wells in bottom water reservoirs are the node flow rate and stacking effect. The improved four types of water flooding modes for bottom water horizontal wells not only clarify the division of the water outlet point and water outlet intensity but also form a corresponding relationship with the actual water cut change curve in production. From the trend of the water cut change curve, the approximate water flooding mode and remaining oil potential can be roughly determined. The case analysis of the Tahe horizontal well shows that using this method can accurately determine the water flooding mode and water outlet point of a single well. The judgment results of water flooding using this method are basically consistent with the production logging results, indicating good application prospects.