Abstract:

Taking well group M of E+K block of YH condensate gas reservoir as a typical example, a numerical simulation model of a typical well group was established to study the main controlling factors and mechanism of EOR by gas injection. The effects of different factors including injection?production positions, injection medium, gas injection volume, injection?production ratio, gas injection timing and pressure recovery degree, on the production performance was simulated and the gas injection scheme of the well group was optimized. The results show that the development of retrograde condensate gas reservoir is optimized under the conditions of "up?down production", cyclic gas injection, gas injection volume（30.50～36.60）×10⁴ m³/d （annual gas injection volume is 2.50%~3.00% of the original geological reserves） and maintain high formation pressure (depleted to no less than the dew point pressure). The research results can provide a basis for the policy formulation of EOR technology in the middle and late stage of gas injection development of YH retrograde condensate gas field and provide guidance for the development adjustment of the gas field in the middle and late stage.

Key words: Condensate gas reservoir, YH condensate gas reservoir, Gas injection for enhanced oil recovery, Numerical simulation

摘要：

以牙哈（YH）凝析气藏E+K区块M井组为例，建立典型井组数值模拟模型，对注气提高采收率主控因素及其机理进行了研究。在注采部位、注入介质、注气量、注采比、注气时机及压力恢复程度不同的条件下，模拟生产效果并对井组注气方案进行了优化。结果表明，采用“上注?下采”、循环注气、注气量（30.50～36.60）×10⁴ m³/d（年注气量为原始地质储量的2.50%～3.00%）、维持较高地层压力（衰竭至不低于露点压力）等条件时，凝析油开发效果较好。研究结果可为YH凝析气田注气开发中后期提高采收率技术政策制定提供依据，为凝析气田中后期开发调整提供指导。

关键词: 凝析气藏, YH凝析气藏, 注气提高采收率, 数值模拟