新疆石油地质 ›› 2022, Vol. 43 ›› Issue (1): 59-65.doi: 10.7657/XJPG20220109

• 油藏工程 • 上一篇    下一篇

低渗透砂砾岩油藏二氧化碳驱提高采收率

李岩1,2(), 张菂3, 樊晓伊1,2, 张金通1,2, 杨瑞莎1,2, 叶欢1,2   

  1. 1.中国石化 河南油田分公司 勘探开发研究院,郑州 450000
    2.河南省提高石油采收率重点实验室,河南 南阳 473132
    3.河南省地震局,郑州 450000
  • 收稿日期:2021-11-02 修回日期:2021-11-18 出版日期:2022-02-01 发布日期:2022-01-24
  • 作者简介:李岩(1973-),男,河南方城人,高级工程师,硕士,油气田开发,(Tel)18503850413(E-mail) liyan_2021@yeah.net
  • 基金资助:
    中国石化科技攻关项目(P17003-5)

EOR of CO2 Flooding in Low-Permeability Sandy Conglomerate Reservoirs

LI Yan1,2(), ZHANG Di3, FAN Xiaoyi1,2, ZHANG Jintong1,2, YANG Ruisha1,2, YE Huan1,2   

  1. 1. Research Institute of Exploration and Development, Henan Oilfield Company, Sinopec, Zhengzhou, Henan 450000, China
    2. Henan Provincial Key Laboratory of Enhanced Oil Recovery, Nanyang, Henan 473132, China
    3. Seismological Bureau of Henan Province, Zhengzhou, Henan 450000, China
  • Received:2021-11-02 Revised:2021-11-18 Online:2022-02-01 Published:2022-01-24

摘要:

焉耆盆地本布图油田低渗透砂砾岩油藏早期采用注水开发,储集层伤害严重,注水困难,采出程度低,亟需开展转换注驱研究,进一步提高采收率。为确定本布图油田低渗透砂砾岩油藏注CO2提高采收率的可行性,开展了室内实验研究。结果表明,研究区地层原油膨胀性好,易降黏,易混相;最小混相压力为25 MPa,在目前地层压力下可达到近混相驱,驱油效率较高,具有大幅提高采收率的潜力。利用数值模拟对CO2驱开发技术进行优化设计,采用五点法井网,连续注气开发,预计提高采收率13.37%,CO2换油率0.330 t/t,为下一步矿场试验提供了理论依据。

关键词: 焉耆盆地, 本布图油田, 低渗透砂砾岩油藏, CO2驱, 提高采收率, 长岩心驱替, 室内模拟实验, 驱油机理

Abstract:

The low-permeability sandy conglomerate reservoirs of Benbutu oilfield in Yanqi basin was developed by water flooding in the early stage. While along with water flooding, the reservoirs were seriously damaged, it was even harder to inject water into the reservoirs and the recovery rate stayed in a low level, therefore, it is urgent to switch flooding agent to further improve the recovery rate. In order to determine the feasibility of CO2 injection in the low-permeability sandy conglomerate reservoirs in Benbutu oilfield to enhance oil recovery, indoor experimental researches were carried out. The research results show that the crude oil in the formation of the study area has good swellability, is easily miscible with the injected CO2, and the viscosity of the crude oil is easy to be reduced. The minimum miscible pressure of the reservoirs is about 25 MPa, and near-miscible flooding can be achieved under the current formation pressure. The oil displacement efficiency of CO2 flooding is relatively high, which can dramatically improve recovery rate. The CO2 flooding plan was optimized with numerical simulation, in which a five-spot well pattern and a continuous gas injection method were adopted, and the oil recovery is expected to increase by about 13.37% and the oil diplacement ratio of CO2 injection will be about 0.33 t/t. The numerical simulation results provide a theoretical basis for the next field application.

Key words: Yanqi basin, Benbutu oilfield, low-permeability sandy conglomerate reservoir, CO2 flooding, enhanced oil recovery, long core flooding, laboratory simulation experiment, oil displacement mechanism

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