石油与天然气地质 ›› 2022, Vol. 43 ›› Issue (2): 286-296.doi: 10.11743/ogg20220204

• 油气地质 • 上一篇    下一篇

加热过程中页岩储层改质效果研究进展

陈国辉1,2,3(), 蒋恕1,2,3, 李醇1,2,3, 李思思1,2,3, 彭鹏1,2,3, 莫兰1,2,3, 张钰莹1,2,3, 张鲁川1,2,3, 张天宇1,2,3   

  1. 1.中国地质大学(武汉) 构造与油气资源教育部重点实验室,湖北 武汉 430074
    2.中国地质大学(武汉) 油气勘探 开发理论与技术重点实验室,湖北 武汉 430074
    3.中国地质大学(武汉) 资源学院,湖北 武汉 430074
  • 收稿日期:2020-10-09 修回日期:2022-01-20 出版日期:2022-04-01 发布日期:2022-03-11
  • 作者简介:陈国辉(1986—),男,教授、博士生导师,页岩油气赋存机理与勘探开发。E?mail: chenguohui@cug.edu.cn
  • 基金资助:
    国家自然科学基金项目(42072174);博新计划项目(BX20190303);中央高校基本科研业务费专项资金项目(102-162301202627);湖北省博士后创新研究岗位项目(247419)

Progress in shale reservoir upgrading through in-situ heating

Guohui Chen1,2,3(), Shu Jiang1,2,3, Chun Li1,2,3, Sisi Li1,2,3, Peng Peng1,2,3, Lan Mo1,2,3, Yuying Zhang1,2,3, Luchuan Zhang1,2,3, Tianyu Zhang1,2,3   

  1. 1.Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,China University of Geosciences (Wuhan),Wuhan,Hubei 430074,China
    2.Key Laboratory of Theory and Technology of Petroleum Exploration and Development,China University of Geosciences (Wuhan),Wuhan,Hubei 430074,China
    3.School of Earth Resources,China University of Geosciences (Wuhan),Wuhan,Hubei 430074,China
  • Received:2020-10-09 Revised:2022-01-20 Online:2022-04-01 Published:2022-03-11

摘要:

中国陆相页岩油资源潜力巨大,但因成熟度偏低、油质重、粘度大、地层流体压力低且孔渗条件差而难以有效开发。原位加热技术可显著提高其采收率,储层改质是该技术的重要目标之一。基于前人对页岩孔隙演化的研究以及对油页岩原位加热过程中储层物性改质的探索,通过理论分析,明确了储层改质效应由孔隙演化和热致裂两种机制控制。孔隙演化主要由有机质裂解、无机矿物成岩转化、矿物溶蚀和重结晶引起;热致裂主要由热应力和生烃增压造成。前期对不同成熟度页岩孔隙演化规律的研究以及对砂岩、花岗岩热破裂作用的研究,为进一步揭示页岩原位加热过程中的储层改质效应奠定了良好基础。但页岩中复杂的矿物成分导致其孔隙演化过程更加复杂,有机质裂解过程所伴随的成孔作用、酸性产物溶蚀作用以及增压效应使该过程进一步复杂化。在进一步研究中,需要对不同作用开展相对独立的研究,揭示其机理并建立预测模型,进而对原位加热过程中整个增孔增渗效应在时间和空间上的演化进行有效预测。

关键词: 孔隙演化, 热致裂, 热应力, 原位加热, 储层改质, 提高采收率, 页岩油

Abstract:

Non-marine oil shale is abundant in China but most of it is not economically accessible due to its low maturity, low API gravity, high viscosity, low-pressure formation fluid as well as low porosity and permeability. In-situ heating technology has been used to improve the recovery rate of the oil and proven quite effective in improving the shale reservoir properties. Based on previous studies on shale pore evolution and reservoir property improvement through in-situ heating of oil shale, this study clarifies that the improvement of shale reservoir properties through heating is realized by both the pore evolution and the thermal cracking. Pore evolution is mainly facilitated by organic matter cracking, inorganic mineral transformation, mineral dissolution and recrystallization. Thermal cracking is mainly induced by thermal stress and hydrocarbon generation supercharging. Despite the insights gained from previous studies on pore evolution pattern of shale of different maturity and on thermal cracking in sandstone and granite, challenge remains in further revealing the effect of reservoir improvement in the in-situ heating process of shale because of the complex mineral composition in shale that leads to a more complex pore evolution process, which is further complicated by pore formation, acid product dissolution and supercharging effect associated with organic matter decomposition. It is therefore suggested that further research be carried out separately on each different effect to reveal the mechanisms and establish models, so as to effectively predict the temporal and spatial evolution of the entire pore and permeability enhancement effect during the in-situ heating process.

Key words: pore evolution, thermal cracking, thermal stress, EOR, in-situ heating, oil shale

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