Study On Method Of Well Pattern Adjustment Of Taizhao Region And On-the-spot Experiment Of Comprehensive Regulation

The low permeability sandstone reservoirs widely develop in petroliferous basins in our country, which account for 30% of the national petroleum resource. The low permeability sandstone is characterized by density, large rock strength and brittleness, so brittle fracture can be developed under tectonic stress field. According to statistics, the low permeability sandstone reservoirs with developed fractures account for 80% of the national low permeability sandstone reservoirs. Fractures are not only reservoir spaces, but also permeable channels, which control flow matrix of reservoir. And, the research on fracture and its seepage network system is the key to reasonable development of fracturing field. Therefore, improving the integral research level of fractures of low permeability sandstone reservoir and expanding producing reserves, absolutely have deep and great significance for sustainable and stable development of national petroleum industry and the policy of"stabilize east". In this paper, aiming at the main contradiction existed in waterflooding process for this area, and taking Zhao 212 as an example, the study on infilled adjustment for the existing pattern have been carried out by use of reservoir numerical simulation. The following main outcome and conclusions are achieved.1.According to core, flake and logging data, compared with other typical fracturing field, the fractures in Taizhao reservoir develop well, and the fractures are important flow channels in this area, which influence on the flow matrix, the pattern arrangement and adjustment, the injection effectiveness analysis and fracturing operation.2.Fractures have influences on oilfield development, which include well-net array, water injection and hydraulic fracturing, etc. Based on the characteristic and function of fractures distribution, and reservoir numerical simulation, rectangular pattern and diamond shaped pattern are reasonable in the low permeability oilfield development.3.Aiming at the main contradiction existed in waterflooding process, and taking Zhao 212 as an example, the study on infilled adjustment for the existing pattern have been carried out by means of reservoir numerical simulation. The result shows that, based on the existing flooding well network, a production well is infilled at the center point of diagonal of initial well drain, and a diagonal well in initial injection wells is converted. Thus, inverted nine-spot injection pattern is produced, the angle between which and fracture is 45o. After water out of corner well in new well pattern, conversion can produce linear injection pattern with 150m row spacing. The effect is good, and the recovery ratio is greatly improved..