Matching Technical Research Of Waterflooding In Low Permeability And Complex Fault-block Oil Reservoir

Huan Xiling oil field is located in the southern tip of the west slope in the western depression of Liao He basin, it has the characteristics of complex structure, various types of reservoirs. Among them, the low permeability sandstone water flooding reservoir possesses the characteristics of deeper burial depth, poor r eservoir property, stronger heterogeneity and high water injection pressure; the intricate minor fault-block water flooding reservoir is characterized by smaller block area(0.32~1.4K m2) and less reserves(24×104t~78×104t), this kind of reservoir property varies with different fault block and it possesses the characteristics of stronger heterogeneity, poor connectivity, longer water injection response phase and a low increasing amplitude of oil.In this paper, the low permeability sandstone water flooding reservoirs of Huandong-Shuang oilfield are affected by many factors, such as poor reservoir property, strong heterogeneity, water and speed sensitivity, large width of oil layer, little thickness of monolayer, poor connectivity and so on. All those reservoirs have many problems in initial development phase, for example, they have a little effect by water flooding development, and they can neither inject water nor withdraw liquid. On the basis of lab analysis and evaluation of the injecting water quality, in order to improve injecting water quality, in this paper,we carried out a lot of technical researches, including water quality fine processing, augmented injection in injecting Wells, nanoparticles film displacing oil and nitrogen auxiliary water displacing technology. All of those did not only improve the water flooding susceptibility, but also formed matching techniques of water flooding development in low permeability and nonrecoverable reserves. They have helped to achieve a transformation of the development mode in low permeability reservoir and they can also effectively ensure the efficient development of low permeability reservoirs.At the same time, on the basis of the scientific evaluation of the complex reservoir, we carried out the deep displacement technology in injection Wells, which effectively enhanced water flooding efficiency and oil recovery of the complex minor fault-block oil reservoir.