厚层块状砂岩油藏天然气驱提高采收率方案研究

Design of block sandstone reservoirs in natural gas drive

H17块D油层是一个具有气顶、边底水的巨厚块状中高渗砂岩稀油油藏。由于储层厚度大,注水开发能量难以有效补充,油藏水锥严重,采出程度低,采油速度低。针对开发存在的问题,为实现油、气重力分异和稳油控水,恢复地层压力,改善开发效果,开展天然气驱开发研究,依据油藏特点,通过室内实验与数模研究相结合,对注气部位、注采参数、生产方式等进行系统优化,提出了顶部注气压锥,实现原油二次聚集,采油井随油环聚集阶梯开采恢复产能的方案,预计采收率提高8.9%。

The oil layer D in block H17 is a mid-high permeability sandstone thin oil reservoir with the gas cap and the bottom- edge 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 pro- duction 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 in- jection-production parameters and the production methods, put forward the pressure cone by the top injection to realize the second- ary 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.