Quantitative Characterization Method of Microscopic Remaining Oil Distribution and Its Application in Laboratory Displacement Experiments

Document Type : Research Paper


1 School of Petroleum Engineering, Northeast Petroleum University, Daqing, China

2 School of Marine Sciences, Sun Yat-sen University, Guangzhou, China\Research Institute of Unconventional Oil and Gas, Northeast Petroleum University, Daqing, China

3 Key Lab of Mineral and Mineralization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China


The study of microscopic remaining oil is of great significance for the effective development of reservoirs after water flooding. An observation and quantitative characterization method of occurrence states of remaining oil on pore scale is proposed in this manuscript. Core columns are frozen immediately after the displacement experiment with liquid nitrogen freezing technology, and the samples are ground to a thickness of 0.05 mm under frozen conditions. Distributions of oil and water in pores are observed with the technology of ultraviolet fluorescence microphotography. The remaining oil content of different types is quantitatively calculated by analysis of characteristic parameters of the core image. Quantitative analysis of the laboratory displacement experimental results indicated that the average oil recovery reaches over 48% after water flooding. The main types of the remaining are throat state, cant state, thin film on pore surface, cluster state, interparticle adherence state and particle adherence state. Their relative contents account for 1.84%, 3.07%, 37.42%, 5.83%, 27.91% and 24.23% of total remaining oil reserves, respectively. Among them, the remaining oil in a thin film on pore surface, remaining oil of interparticle adherence, and remaining oil of particle adherence with high content are the development targets after water flooding. Based on determining the type and distribution characteristics of the microscopic remaining oil, the mechanism and influential factors of different types of microscopic remaining oil are analyzed, and the exploitation method for different types of remaining oil is proposed. This study is of great significance for guiding the development of remaining oil after water flooding and improving enhanced oil recovery.


  1. Lin C Y, Yu C L, Dong C M, Wang Y J, Liu W, Ma C D, Liu H T, Song B (2011) Remaining oils distribution in old oilfields: Enrichment of remaining oils in underwater distributary channel crotches, Acta Petrolei Sinica, 32, 5: 829-835. ##
  2. Lin C Y, Sun T B, Dong C M, Li Z P, Tian M, Li S J (2013) Fine characterization of remaining oil based on a single sand body in the high water cut period. Acta Petrolei Sinica, 34, 6: 1131-1136. ##
  3. Qiao Y P, Shao X J, Jie J T, Liang W B, Li S C, Chen X Z (2015) Summary of the residual oil distribution and research methods in high water-cut stage, Inner Mongolia Petrochemical Industry, 25, 9: 132- 136. ##
  4. Yan W C, Sun J M (2016) Analysis of research present situation of microscopic remaining oil, Progress in Geophysics, 31, 5: 2198-2211. ##
  5. Tian L, Liu J, Yao Q Z (2021) Evolution and hydrocarbon accumulation of the cambrian-ordovician paleo-uplifts in the southwest tarim depression, China, Journal of Petroleum Science and Technology, 11, 1: 35-42. ##
  6. Song K P, Li S J, Fang W, Wu J W, Mu W Z (2005) Study on alterations of microscopic remaining oil after polymer flood by method of fluorescent analysis, Acta Petrolei Sinica, 26, 2: 92-95. ##
  7. Liu Y K, Fan M, Zhang D, Wang F J, Liang S, Zhao X Y (2015) Microscopic characteristics of the remained oil after ASP flooding, Petroleum Geology and Oilfield Development in Daqing, 34: 117-120. ##
  8. Guo Y G (2017) Relationship between pore-throat structure and remaining oil distribution in extra -low permeability reservoir, Fault-Block Oil and Gas Field, 24: 218-221. ##
  9. Li Y Q, Li J J, Ding S W, Sun X D (2014) Characterization of remaining oil after polymer flooding by laser scanning confocal fluorescence microscopy, Journal of Dispersion Science and Technology, 35: 898-906. ##
  10. Cheng J C, Wang D, Li Q, Yang Z Y (2002) Field test performance of alkaline surfactant polymer flooding in Daqing oilfield, Acta Petrolei Sinica, 23, 6: 37-40. ##
  11. Chatzls M S, Kuntamukkula N R M (1988) Effect of capillary number on the microstructure of residual oil in strongly water-wet sandstones, SPE, 13213: 902-912. ##
  12. Song K P, Yang Z, Shu Z H, Fang W (2004) Influencing factors of microscopic distribution of remaining oil of polymer flood, Journal of Daqing Petroleum Institute, 28, 2: 25-27. ##
  13. Hou J, Zhang S K, Yuan S B (2006) Study on quantitative analysis of remaining oil distribution in microscopic filtration experiment of polymer flood, Journal of Hydrodynamics, 21, 1: 42-44. ##
  14. Liu C P, Yan W L, Yang Q S, Ma H Y (2010) Logging response characteristic analyses and saturation calculation method for polymer flooded reservoir, SPE, 131472: 1-8. ##
  15. Li Y Q, Sui X G, Li J (2005) Laboratory experiment study of sweep efficiency of polymer flood of vertically heterogeneous large-scale areal model, Acta Petrolei Sinica, 26, 2: 77-79. ##
  16. Sun S R, He X H, Wu X, Lu X G (2003) Experimental study on nuclear magnetic imaging of remaining oil distribution after polymer flood, Petroleum Geology and Oilfield Development in Daqing, 22, 4: 61-63. ##
  17. Pan S W, Liang H J, Li L, Luo H N, Wang J H (2013) Research progress on simulation of microscopic remaining oil, Lithologic Reservoirs, 25: 16-20. ##
  18. Ma B Y, Xu S Y (2016) Overview on research methods of microcosmic remaining oil distribution, Zhongzhou Coal, 251: 142-145,150. ##
  19. Behin R, Sharifi Galiuk H (2011) Study of two-phase fluid flow in water wet reservoir rocks by using x-ray in situ saturation monitoring, Journal of Petroleum Science and Technology, 1, 1: 15-23. ##
  20. Peng R D, Yang Y C, Ju Y, Mao L T, Yang Y M (2011) fractal dimension calculation of rock pores based on grey scale CT images, Chinese Science Bulletin, 26: 2256-2266. ##
  21. Evgenia V L, Andrew F (2011) Micro-CT and wettability analysis of oil recovery from sand packs and the effect of waterflood salinity and kaolinite, Energy and Fuels, 25, 12: 5683–5694. ##
  22. Yang P, Guo H K, Yang D Y (2013) Determination of residual oil distribution during waterflooding in tight oil formations with NMR relaxometry measurements, energy and fuels, 27, 10: 5750–5756. ##
  23. Li J, Tan Y Y (2004) Study on microscopic distribution of remaining oil after polymer flood by fluorescent analysis of core sections——take member pu i of daqing oilfield as example, Petroleum Geology and Recovery Efficiency, 11, 6: 64-85. ##
  24. Wu J W (2009) Study on distributuion rules of fluids in micro pores of low permeability reservoir, Daqing Petroleum Institute, Daqing, China, 1-15. ##
  25. Cao Z Z, Chen Y X, Yu T X (2005) Study on application of quantitative fluorescence technique in reservoirs with low porosity and permeability, Mud Logging Engineering, 16, 3: 19-24. ##
  26. Stasiuk L D, Snowdon L R (1997) Fluoresence micro-spectrometry of synthetic and natural hydrocarbon fluid inclusion: Crude oil chemistry, density and application to petroleum migration, Applied Geochemistry, 12: 229-241. ##
  27. Munz I A (2001) Petroleum inclusions in sedimentary basins Systematics,analytical methods and applications, Lithos, 55: 195-212. ##
  28. Goldstein R H, Reynolds T J (1994) Systematics of fluid inclusions in diagenetic minerals, SEPM Short Course, 31: 69-85. ##
  29. Przyjalgowski M A, Ryder A G, Feely M (2005) Analysis of hydrocarbon-bearing fluid inclusions (HCFI) using time-resolved fluorescence spect roscopy, Optical Sensing and Spectroscopy, 5826: 173-184. ##
  30. Yu X Y, Shi J X (1996) Application of infrared, ultraviolet and fluorescent analysis in study of organic inclusion, Acta Mineralogica Sinica, 16, 2: 212-217. ##
  31. Zou H F, Xu X C, Gao F H (2002) Microscopic fluorescent analysis of pre-tertiary in dagang prospect and study on hydrocarbon migration characteristics, Global Geology, 21, 3: 247-248. ##
  32. Guo S L (1994) Techology of fluorescent microscope, petroleum industry press, Beijing, China, 30-45. ##
  33. Yang K, Xu S Y (2009) Experiment methods of microcosmic remaining oil, Fault-Block Oil and Gas Field, 16, 4: 75-77. ##
  34. Bai Z Q, Wu S H, Fu Z G (2013) The distribution of microcosmic remaining oils after polymer flooding in daqing oilfield, Acta Petrolei Sinica, 34, 5: 924-931. ##