Research and Practice on Liquid Extraction in Late Water Flooding of Ultra Deepwater Facies Sandstone Reservoirs

As the largest ultra deep sea facies sandstone reservoir in Tarim Oilfield, Donghe sandstone reservoir in Hudson Oilfield has entered the late stage of water drive. Compared to the eastern oilfield, the Donghe sandstone reservoir is deeply buried, with large injection production well spacing, strong reservoir heterogeneity, and sufficient edge and bottom water energy, resulting in complex distribution of remaining oil, making it difficult to implement stable oil and controlled decline technology. Limited by geological conditions and development factors, fluid extraction from Hudson Donghe sandstone reservoir is faced with problems such as how to select wells, how to determine the timing of fluid extraction, and how to calculate the amplitude of fluid extraction. In view of a series of difficulties faced by liquid extraction in the late stage of water drive in ultra deep sea facies sandstone reservoirs, explore the development characteristics of dominant percolation channels, clarify the microscopic residual oil distribution patterns, and propose a geological model for liquid extraction and oil increase. Using the split flow equation, the phase permeability curve of a single well and the dynamic parameters of dimensionless liquid production and oil production index are calculated, and a comprehensive evaluation method for the timing and volume of liquid extraction is established. This method has good field application effect and explores a new way to stabilize oil and water production for ultra deep sea facies sandstone.