Quantitative evaluation method and application of wettability of shale multi-scale storage space

• Published in: International journal of hydrogen energy Vol. 89; pp. 541 - 569
• Main Authors: Fu, Xiaofei, Wei, Jianguang, Hou, Zhaowei, Wang, Anlun, Zhou, Xiaofeng, Yang, Ying
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 04.11.2024
• Subjects: External fluids/shale oil; Interface tension; Multiscale shale reservoir space; Nuclear magnetic resonance; Wettability; External fluids/shale oil; Wettability; Nuclear magnetic resonance; Interface tension; Multiscale shale reservoir space
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2024.09.184

The quantitative evaluation of the wettability of shale multi-scale reservoir space is the basis for efficient shale oil development. In this paper, firstly, innovative quantitative evaluation method and application for the wettability of shale multi-scale storage space is studied. Secondly, a quantitative evaluation method for the multi-scale reservoir space wettability of the Gulong shale and the impact of external fluids on the wettability of the Gulong shale is established. Thirdly, the interfacial tension between different types of injection media and shale oil under different temperature and pressure conditions is clarified. Results show that: (a) The effect of external fluids on improving the overall hydrophilicity of shale (change in water oil ratio) is ranked as follows: GJ surfactant (0.06) > guanidine gum (0.03) > slick water (−0.01); (b) The effect of external fluids on improving the hydrophilicity of pores in shale (water oil ratio change value) is ranked as follows: GJ surfactant (0.80) > guanidine gum (0.24) > slick water (0.19); (c) Under geological conditions, the interfacial tension between the injected medium and shale oil is 0–0.3 mN/m: GJ surfactant (0.018), alkaline solution (0.142), GJ surfactant + acid solution (volume ratio 2:1) (0.195), and alkylbenzene sulfonate solution (0.263). •Fluids identification in shale of different scales is achieved using 2D NMR technology.•A quantitative evaluation method for multi-scale shale reservoir space wettability is established.•The interfacial tension between different types of injection media and shale oil is clarified.