石油学报 ›› 2011, Vol. 32 ›› Issue (2): 307-310.DOI: 10.7623/syxb201102018

• 油田开发 • 上一篇    下一篇

特低渗透油藏天然气非混相驱实验

魏浩光 1  岳湘安 1  赵永攀 1  何建华 2   

  1. 1 中国石油大学石油工程教育部重点实验室  北京  102249; 2 中国石化江汉油田分公司勘探开发研究院  湖北潜江  433110
  • 收稿日期:2010-07-25 修回日期:2010-09-07 出版日期:2011-03-25 发布日期:2011-05-25
  • 通讯作者: 魏浩光
  • 作者简介:魏浩光,男,1982年8月生,2005年毕业于大庆石油学院,现为中国石油大学(北京)在读博士研究生,主要研究方向为油藏工程与提高采收率技术。
  • 基金资助:

    国家科技重大专项(2009ZX05009)“复杂油气田地质与提高采收率技术”资助。

An experimental investigation of the nature gas immiscible displacement in ultra-low permeability reservoirs

WEI Haoguang 1  YUE Xiang’an 1  ZHAO Yongpan 1  HE Jianhua 2   

  • Received:2010-07-25 Revised:2010-09-07 Online:2011-03-25 Published:2011-05-25

摘要:

利用单层和双层物理模型,开展了特低渗透油藏注天然气开采模拟实验。单层模型实验结果表明,特低渗透油藏天然气驱同水驱相比不仅可以提高驱油效率,还能提高微观波及效率;天然气驱采收率比水驱采收率高4.50%,水驱后注天然气的开采效果更好,可提高采收率幅度达12.50%;未见气与低气液比阶段内油井的产能高,是主要生产期。双层非均质模型实验结果表明,由于油藏内实际的层间渗透率级差比实验室内测定的级差大得多,同一套开发层系内低渗透层不具备吸气能力,气体完全进入高渗透层,高渗透层的开发效果非常好;天然气在高渗透层中形成窜流后,剩余油主要分布于低渗透层中,需要用凝胶体系对高渗透层进行封堵;封堵后,低渗透层的吸气能力非常强,能被充分开发利用,双层非均质模型的采收率由30.85%提高到55.91%。

关键词: 特低渗透油藏, 天然气, 非混相驱, 采收率, 开发层系, 封堵

Abstract:

With a monolayer or two-layer physical model, a simulation experiment of the natural gas displacement in ultra-low permeability reservoirs was carried out. The results from the monolayer physical model showed that compared with water flooding, gas flooding in ultra-low permeability reservoirs might enhance not only the displacement efficiency but also the micro-sweep efficiency, increasing the recovery ratio by 4.5%. The subsequent natural gas injection after water flooding could gain a better effect of development, increasing the recovery ratio by 12.5%. Deliverability in oil wells kept high during the non-gas and low gas-liquid ratio stages, which were the major production period. The experimental results from the two-layer heterogeneous model indicated that since the real difference in interlayer permeability rates within reservoirs was much greater than that measured in laboratory, within the same suite of developed layers, the low permeable layer failed to inhale while the high permeable layer was well exploited due to gas flooding. The remaining oil would occur mainly in the low permeable layer as the high permeable layer was plugged with gel after a gas crossflow formed. After the plugging of the high permeable layer, the low permeable layer became active in gas-intake and could be completely exploited. The recovery ratio by the two-layer heterogeneous model was enhanced from 30.85% to 55.91%.

Key words: ultra-low permeability reservoir, natural gas, immiscible displacement, recovery ratio, layer system of development, plugging