The oil layer D in block H17 is a mid-high permeability sandstone thin oil reservoir with the gas cap and the bottomedge water. Because of the huge thickness

the water flooding is difficult to effectively supplement the energy. The water coning is serious and the recovery degree and production rate are low. In order to realize the oil/gas gravitational differentiation

the oil production stabilization and water control

the formation pressure recovery and the development effect improvement

the research and development of the natural gas injection were carried out. Meanwhile

based on the characteristics of the reservoir

and through the combination of the laboratory experiment and the numerical simulation

we systematically optimize the gas injection position

the injection-production parameters and the production methods

put forward the pressure cone by the top injection to realize the secondary accumulation

and propose the deliverability of the oil production wells recovered by bench stoping gathering with oil ring.There’s a 8.9 % increase expected in the recovery efficiency.