The Numerical Simulation Research On High Pressure Air Injection After Water Flooding In Low Permeability Reservoirs Of Shen 161 Block

Injecting air into the light oil reservoir can be thought as a new methord that improving tertiary oil recovery. The exothermic chemical reaction occurs between the oxygen and crude oil. In the presence of light oil, these reactions are mainly oxidation reaction. These reactions are not only to generate heat but also to produce carbon oxides with oxygen consumption(mainly CO and CO2).Shen 161 Block that is studied in this paper is the deep low permeability light oil reservoirs. Currently, it has entered the middle and later periods of the waterflood development phase. The main problems that face are high water injection pressure, the difficulty of water injection and low recovery degree. After 18 years water flooding development, the fault block recovery degree is only 13.0%. There are still 48.7681×104t remaining recoverable reserves that are not effectively used, and the next oilfield development still has great potential. Therefore, clearing residual oil distribution and researching on improving oil recovery by air injection with high pressure become the key points of this study.According to the actual static data and application reservoir engineering analysis methods of empirical formula method and water drive curve method, this paper studies the oil recovery after water flooding, reservoir natural energy, the changing law of water cut, the adaptability of current well pattern and well spacing and so on; on the basis of fine 3D geological model, making use of the Eclipse numerical simulation software remaining oil distribution in the study area was researched; according to the remaining oil distribution and development characteristics of the study area, numerical simulation model of air injection with high pressure was established, and the test area was selected.Well pattern and well spacing of air injection with high pressure had been carried on the preliminary demonstration and reasonable gas injection parameters are given. On this basis, the overall plan of air flooding with high pressure was projected in the study area. The block oil recovery rate was 10.02% after air injection with high pressure through the production indexes and economic evaluation. A theoretical basis for the implementation of air injection with high pressure technology was provided and was an important guiding significance.