Water plugging adaptability under different water-flooding modes in Tahe bottom-water sandstone reservoirs

When the horizontal wells of sandstone reservoirs with bottom water have water, their productions will fall quickly and sharply. Water flooding, as an effective measurement in horizontal well management, is restricted by water flooding extent. As a result, it is necessary to study the characteristics of water flooding and the adaptability of water plugging in horizontal wells. We studied the influence of permeability association type of horizontal sections of horizontal wells in bottom-water reservoirs of the Tahe Oil Field on the water flooding mode of oil wells. There are four flooding modes, including dot flooding, step flooding, multistage flooding and uniform flooding, according to the flooding extent of horizontal sections. Corresponding plugging techniques were proposed in view of residual oil distribution. Under the modes of dot flooding and multistage flooding, oil usually remains in low-permeability sections and is mixed with water, and multi-round water-plugging is recommended. The oil and water mixing sections will turn to the main potential sections in horizontal wells during multi-round water-plugging. Complex water-plugging with block and hydrophobicity to dig the potential is recommended.