关键词: 低渗透油藏, 精细油藏描述, 砂体精细刻画, 精细水驱技术, 水驱效果

Abstract: Low-permeability reservoirs are characterized for dense lithology, fine pore throat, low pressure coefficient, and development of natural fractures. Water injection development come across some problems, such as low single-well production, rapid production decline and weak basis for stable production. The reservoirs are serious in heterogeneity with low producing degree and low displacing degree. It is easy for water flooding and channeling, leading to low oil production rate and production factor. To overcome those problems, the fine reservoir description technology has been developed thanks to tenacious research. The technology, matched with the fine layered water injection process, is successfully applied to development of low-permeability reservoirs. Fine reservoir description serves as the basis for adoption of fine water flooding, mainly including fine characterization of single sand body, fine characterization of fractures, and fine characterization of micro pore structure of reservoir. Fine water flooding includes well pattern infill and adjustment technology, fine layered water injection technology, intelligent layered water injection technology, nano micro-ball flooding adjustment technology and mild advanced water injection technology. It can settle the contradiction of imbalance between low-permeability water injection development level and vertical water-injecting production, thus effectively improving the production factor. Mild advanced water injection technology is of great importance to overcoming the contradictions among opening of fractures, fracturing of formations and starting of pressure gradient, making the formation pressure kept under a relatively stable state and in favor of extending the stable production period of oilfields. As compared to conventional water flooding, fine water flooding technology is expected to improve the production factor of low-permeability reservoirs by more than 5 percent.