新疆石油地质

新疆石油地质 ›› 2025, Vol. 46 ›› Issue (1): 114-120.doi: 10.7657/XJPG20250114

• 应用技术 • 上一篇    下一篇

三塘湖油田NJH区块中黏油CO2近混相驱实验及应用

张琦1a(), 朱永贤2, 韩天会1b   

  1. 1.中国石油 吐哈油田分公司 a.勘探开发研究院；b.开发事业部，新疆 哈密 839000
    2.中国石油 吐哈油田分公司，新疆 哈密 839000
  • 收稿日期:2024-07-01 修回日期:2024-08-25 出版日期:2025-02-01 发布日期:2025-01-24
  • 作者简介:张琦（1994-），男，吉林松原人，工程师，硕士，油气开发，（Tel）0902-2770404（Email）zhangqiyjy@petrochina.com.cn
  • 基金资助:
    中国石油天然气股份有限公司科技项目(2023YQX10408ZK)

Laboratory Experiments and Field Tests of CO2 Near-Miscible Flooding for Medium-Viscosity Oil in NJH Block, Santanghu Oilfield

ZHANG Qi1a(), ZHU Yongxian2, HAN Tianhui1b   

  1. 1. PetroChina Tuha Oilfield Company, a.Research Institute of Exploration and Development; b. Development Department, Hami, Xinjiang 839000, China
    2. Tuha Oilfield Company, PetroChina, Hami, Xinjiang 839000, China
  • Received:2024-07-01 Revised:2024-08-25 Online:2025-02-01 Published:2025-01-24

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摘要：

三塘湖油田NJH区块属于中黏油砂岩油藏，地层原油黏度为20.8 mPa·s，处于中含水期，预测水驱采收率为22.70%，提高采收率空间小。为了探索提高采收率技术，检验中黏油CO2近混相驱可行性，揭示CO2近混相驱相间传质规律及增油机理，开展了CO2驱油室内实验及矿场试验。 结果表明：CO2驱前缘主要发挥溶胀作用，后缘萃取抽提作用强于前缘，降黏作用及提高剩余油驱油效率是主要的增油机理，地面原油黏度降幅为55%，C2—C15含量升高18.3%，驱油效率提高4.6倍；渗透率级差是影响波及体积的主要因素，渗透率级差达到6，低渗透层采收率仅为13.84%。矿场试验阶段累计注气量为2.66×104 t，累计产油量为0.78×104 t，换油率达到0.29，证实中黏油CO2近混相驱具备良好的推广应用前景。

关键词: 三塘湖油田, NJH区块, 中黏油, CO2驱油, 近混相驱, 提高采收率, 矿场试验

Abstract:

The NJH block of the Santanghu oilfield features sandstone reservoirs containing medium-viscosity oil, with crude oil viscosity of 20.8 mPa·s. The reservoir is at medium water cut stage, with a predicted waterflood recovery factor of 22.70%, leaving a limited potential for further enhanced oil recovery. To figure out an applicable enhanced oil recovery (EOR) technique, laboratory experiments and field test were conducted on CO2 near-miscible flooding for medium-viscosity oil to understand the mass transfer patterns and EOR mechanisms of this technique, thereby determining its feasibility. The research results show that the front of the CO2 flooding mainly plays a swelling effect, and the rear exerts a stronger extraction effect than the front. Reducing the viscosity and improving the remaining oil displacement efficiency are the main stimulation mechanisms. The viscosity of surface crude oil reduced by 55%, the content of C2-C15 components increased by 18.3%, and the displacement efficiency improved by 4.6 times. Permeability ratio is found to be the primary factor influencing swept volume, with a permeability ratio of 6, leading to a recovery factor of only 13.84% in low-permeability layers. During the field test, the cumulative injected gas volume is 2.66×104 t, cumulative oil production is 0.78×104 t, and oil exchange ratio is 0.29, confirming a promising application of CO2 near-miscible flooding for medium-viscosity oil.

Key words: Santanghu oilfield, NJH block, medium-viscosity oil, CO2 flooding, near-miscible flooding, enhanced oil recovery, field test

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