石油学报 ›› 2022, Vol. 43 ›› Issue (4): 533-547.DOI: 10.7623/syxb202204007

• 油田开发 • 上一篇    下一篇

页岩储层渗吸过程中水的微观分布及其气测渗透率动态响应特征

朱秀川1,2, 胡钦红3, 蒙冕模1,2, 张军建4, 张涛1,2, 尹娜1,2, 孙小惠1,2, 晁静5, 杜玉山5, 刘惠民5   

  1. 1. 中国石油大学(华东)山东省深层油气重点实验室 山东青岛 266580;
    2. 青岛海洋科学与技术试点国家实验室 山东青岛 266071;
    3. 美国德克萨斯大学阿灵顿分校 德克萨斯州阿灵顿 76019;
    4. 山东科技大学地球科学与工程学院 山东青岛 266590;
    5. 中国石油化工股份有限公司胜利油田分公司 山东东营 257000
  • 收稿日期:2021-03-27 修回日期:2022-01-02 发布日期:2022-04-30
  • 通讯作者: 胡钦红,男,1965年7月生,1995年获美国亚里桑那大学博士学位,现为美国德克萨斯大学阿灵顿分校教授,主要从事裂隙基岩相互作用、微观孔隙结构和宏观页岩油气的赋存和运移行为研究。Email:water19049@gmail.com
  • 作者简介:朱秀川,男,1997年2月生,2019年获中国石油大学胜利学院资源勘查工程专业学士学位,现为中国石油大学(华东)硕士研究生,主要从事页岩孔隙结构表征、页岩油气的赋存和运移方面的研究。Email:xiuchuan9702@163.com
  • 基金资助:
    国家自然科学基金重点项目"陆相页岩油在基质-裂缝体系中的多尺度运移机理研究"(No.41830431)资助。

Microscopic distribution of water in the imbibition process of shale reservoir and dynamic response characteristics of its gas logging permeability

Zhu Xiuchuan1,2, Hu Qinhong3, Meng Mianmo1,2, Zhang Junjian4, Zhang Tao1,2, Yin Na1,2, Sun Xiaohui1,2, Chao Jing5, Du Yushan5, Liu Huimin5   

  1. 1. Shandong Provincial Key Laboratory of Deep Oil and Gas, China University of Petroleum, Shandong Qingdao 266580, China;
    2. Pilot National Laboratory for Marine Science and Technology (Qingdao), Shandong Qingdao 266071, China;
    3. University of Texas at Arlington, Arlington Texas 76019, USA;
    4. College of Earth Science and Engineering, Shandong University and Technology, Shandong Qingdao 266590, China;
    5. Sinopec Shengli Oilfield Company, Shandong Dongying 25700, China
  • Received:2021-03-27 Revised:2022-01-02 Published:2022-04-30
  • Contact: 胡钦红,男,1965年7月生,1995年获美国亚里桑那大学博士学位,现为美国德克萨斯大学阿灵顿分校教授,主要从事裂隙基岩相互作用、微观孔隙结构和宏观页岩油气的赋存和运移行为研究。Email:water19049@gmail.com

摘要: 在页岩油气储层水力压裂过程中,压裂液的滤失行为会增加储层的含水饱和度、降低储层渗透率。研究压裂液侵入对储层渗透率的影响,对于页岩油气的高效开发具有重要意义。为此,针对渤海湾盆地沾化凹陷沙河街组三段下亚段灰质页岩和混合质页岩岩相样品,通过自发渗吸实验获得了样品不同含水饱和度行为,利用核磁共振表征水在孔隙中的动态运移,结合覆压渗透率定量表征气测渗透率动态变化。实验结果表明:①在含水饱和度为5%~40%的渗吸过程中,以微孔(核磁共振T2<1 ms)吸水为主,T2谱累积信号呈上升趋势,占比逐渐增加,而中孔和大孔的T2累积信号呈缓慢上升和波动状态且占比逐渐降低。当含水饱和度达到40%时,微孔累积信号占比高达87%以上。②水化改善作用与水锁和水敏损害相互制约,影响渗透率的动态变化,主要分为3种制约状态(水化远大于、大于、小于水锁和水敏)。结合矿物组分和孔隙结构分析发现,在黏土矿物含量为25%~43%的页岩中,渗透率损害率与黏土矿物和石英含量呈正相关,与脆性指数和碳酸盐矿物含量呈负相关性,灰质页岩水化改善作用优于混合质页岩,且大于1 μm孔喉的发育既能促进水化改善作用,又能降低水锁和水敏对孔喉的损害。

关键词: 页岩油储层, 含水饱和度, 核磁共振, 气测渗透率, 自发渗吸

Abstract: In the process of hydraulic fracturing in shale oil and gas reservoirs, the leakage behavior of fracturing fluid can increase the water saturation of reservoirs, and reduce the permeability of reservoirs. A study on the influence of fracturing fluid invasion on the effective permeability of reservoirs is of great significance for the efficient development of shale oil and gas. Therefore, in view of the calcareous and mixed shale lithofacies samples in the lower sub member of Member 3 of Shahejie Formation, Zhanhua sag, Bohai Bay Basin, different water saturations of samples were obtained through spontaneous imbibition test in the laboratory, the dynamic migration of water in pores was characterized by nuclear magnetic resonance (NMR), and the dynamic changes in gas permeability was characterized quantitatively using overburden permeability. The results shows that:(1) When the water saturation ranges from 5% to 40%, the imbibition process is dominated by small pores (NMR T2<1 ms), and the cumulative signalof T2 spectrum shows an upward trend and its proportion is gradually increased; the cumulative signal of T2 spectrum in the mesopores and macropores slowly rises or fluctuates up and down, respectively, and their proportions are gradually decreased. When the water saturation reaches 40%, the cumulative signal of small pores accounts for as high as 87% and more. (2) The hydration improvement effect and the damage of water blocking and water sensitivity are interacting, and thus affect the dynamic changes in permeability, which can be mainly divided into three states, i.e., hydration improvement is far greater than, greater than, and less than water-locking and water-sensitivity. Further, through the analysis of mineral composition and pore structure, it is found that in the shale with a clay mineral content of 25%-43%, the damaging rate of permeability is positively correlated with clay mineral and quartz contents, while negatively correlated with brittleness index and the carbonate content; calcareous shale has a better hydration improvement than mixed shale, and the development of the pore-throat greater than 1 μm not only can promote hydration improvement, but can reduce the damages of water blocking and water sensitivity to the pore throat.

Key words: shale oil reservoir, water saturation, nuclear magnetic resonance (NMR), gas permeability, spontaneous imbibition

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