Abstract
CO2 flooding can significantly improve the recovery rate, effectively recover crude oil, and has the advantages of energy saving and emission reduction. At present, most domestic researches on CO2 flooding seepage experiments are field tests in actual reservoirs or simulations with reservoir numerical simulators. Although targeted, the promotion is poor. For the characterization of seepage resistance, there are few studies on the variation law of seepage resistance caused by the combined action in the reservoir. To solve this problem, based on the mechanism of CO2, a physical simulation experiment device for CO2 non-miscible flooding production manner is designed. The device adopts two displacement schemes, gas-displacing water and gas-displacing oil, it mainly studies the immiscible gas flooding mechanism and oil displacement characteristics based on factors such as formation dip angle, gas injection position, and gas injection rate. It can provide a more accurate development simulation for the actual field application. By studying the variation law of crude oil viscosity and start-up pressure gradient, the characterization method of seepage resistance gradient affected by these two factors in the seepage process is proposed. The field test is carried out for the natural core of the S oilfield, and the seepage resistance is described more accurately. The results show that the advancing front of the gas drive is an arc, and the advancing speed of the gas drive oil front is slower than that of gas drive water; the greater the dip angle, the higher the displacement efficiency; the higher the gas injection rate is, the higher the early recovery rate is, and the lower the later recovery rate is; oil displacement efficiency is lower than water displacement efficiency; taking the actual core of S oilfield as an example, the mathematical representation method of core start-up pressure gradient in low permeability reservoir is established.
Similar content being viewed by others
Abbreviations
- K :
-
fluid measuring permeability, µm2
- Q :
-
liquid flow, cm3/s
- L :
-
height of gravel filled, cm
- A :
-
section area, cm2
- ρ :
-
fluid density, kg/cm3
- g :
-
acceleration of gravity, m/s2
- μ :
-
liquid viscosity, mPa·s
- h :
-
discharge head, m
- ϕ :
-
porosity, %
- \({\mu _{{T_1}}}\) :
-
Viscosity of crude oil at pressure 1 atm, temperature T1, mPa·s
- \({\mu _{{T_2}}}\) :
-
Viscosity of crude oil at pressure 1 atm, temperature T2, mPa·s
- μ 1 :
-
Viscosity of crude oil at pressure of 1 atm (0.101MPa), mPa·s
- μ 2 :
-
Viscosity of crude oil at pressure p, mPa·s
- A T :
-
Proportion coefficient of temperature and crude oil density
- γ :
-
crude oil density, kg/cm3
- R s :
-
solubility, g
- T :
-
temperature, °C
- P :
-
pressure, pa
- V :
-
volume fraction
- α:
-
Empirical coefficients of temperature, pressure and crude oil density
- F S :
-
inflation factor
- \({F_{{\rm{C}}{{\rm{O}}_2}}}\) :
-
the ratio of CO2 volume under standard condition to the volume under reservoir temperature and pressure
- F o :
-
the ratio of the volume of crude oil under reservoir temperature and 0.1MPa pressure to the volume under reservoir temperature and reservoir pressure
- τ o :
-
Yield stress of formation crude oil, N/m2
- r H :
-
Oil supply radius of well area, m
- R w :
-
Effective oil supply radius, m
- F:
-
the utilization degree of movable oil
- A:
-
drainage area, m2
- \({{\Delta p} \over {\Delta L}}\) :
-
Effective displacement pressure gradient, MPa/m
- n :
-
Fitting index
- τ o :
-
Shearing stress, MPa
- C:
-
Fluid component content, %.
References
Chung F T H, Jones R A, Hai T N (1988). Measurements and correlations of the physical properties of CO2/heavy-crude-oil mixtures. SPE15080, 3(3): 822–828
Deng Y Z, Wu S Y, Zhang G Z, Zong X W (1996). Change of reservoir physical properties during development by waterflood. Oil Gas Recove Techn, (04): 51–59+6
Deng Y E, Liu C Q (1998). Theory of oil-water flow through porous media and calculation of development indexes with starting gradient included. Petrol Explor and Develop, (06): 53–56+6+13
Dai Y S, Jin Z L (1999). Application of analogousness theory in simulate experiment. In: The 8th National Conference on Plastic Processing theory and New Technology, 26–27
Feng G Q, Liu Q G, Shi G Z, Lin Z H (2008). An unsteady seepage flow model considering kickoff pressure gradient for low-permeability gas reservoirs. Petrol Explor Develop, (04): 457–461
Guo X Q, Rong S X, Yang J T, Guo T M (1999). The viscosity model based on PR education of state. Acta Petrol Sin, (03): 64–69+6
Geng H Z, Chen J W, Sun R Y, Li D X (2004). Effect of dissolved carbon dioxide on the viscosity of crude oil. J U Petrol (Nat Sci Ed)(04): 78–80
Guo Y W, Yang S L, Li L C, Wang G, Zhao W X (2009). Experiment on physical modeling of displacement oil with natural gas for long core. Fault-Block Oil Gas Field, 16(6): 76–78
Huang Y Z (1998). Seepage Mechanism of Low Permeability Reservoir. Beijing: Petroleum Industry Publishing House, 80–86
Han H B, Cheng L S, Zhang M L, Cao Q Y, Peng D G (2004). Physical simulation and numerical simulation of ultra-low permeability reservoir in considering of starting pressure gradient. J U Petrol (Nat Sci Ed), (06): 49–53
Ju B S, Fan T L, Zhang J C, Wang X D (2006). Oil viscosity variation and its effects on production performance in water drive reservoir. Pet Explor Dev, (01): 99–102
Jiang H F, Lei Y G, Xiong X, Yan L P, Pi W F, Li X J, Yu C H (2008). An CO2 immiscible displacement experimental aiming at Fuyang extra-low permeability layer at peripheral of Daqing placanticline. Geoscience, (04): 659–663
Jiang L P, Li M, Jiang P, Lao Y C, Liu S Q (2009). A research on the seepage of low-permeability reservoirs under consideration of threshold pressure and pressure-sensitive effect: a case study of member L1 member in Weixi’ nan depression. China Offshore Oil Gas, 21(06): 388–392
Li B T, Guo T M (1990). Measurement and correlation of high pressure viscosities of reservoir crude oil. Pet Explor Dev, (06): 72–79
Lederer E L (1993). Mischungs-und verdünnungs viscosität. In: Proc., World Pet. Cong., London, 2, 526–28
Li Z Q, Li X Y, Yuan M Q, Huang D G, Zhang G G (2000). Study on laboratory experiments of CO2 drive in Shang 13–22 unit. Oil Gas Recove Techn, (03): 9–11+5
Lv C Y, Wang J, Sun Z G (2002). An experimental study on starting pressure gradient of fluids flow in low permeability sandstone porous media. Pet Explor Dev, (02): 86–89
Li Z X, Han H B, Cheng L S, Zhang M L, Shi C E (2004). A new solution and application of starting pressure gradient in ultra-low permeability reservoir. Pet Explor Dev, (03): 107–109
Li Z F, He S L (2005). Influence of boundary layer upon filtration law in low permeability oil reservoirs. Petrol Geo Oilfield Develop Daping, (02): 57–59+77-107
Li B Z, Li X F, Kamy S, Yao Y D (2010a). Optimization of the injection and production Schemes during CO2 flooding for tight reservoirs. J Southwest Petrol U (Sci and Techn Ed), 32(02): 101–107+203
Li D X, Su Y L, Gao H T, Geng Y H (2010b). Fluid parameter modification and affecting factors during immiscible drive with CO2. J China U Petrol (Nat Sci Ed), 34(05): 104–108
Liu W D, Liu J, Sun L H, Li Y, Lan X Y (2011). Influence of fluid boundary layer on fluid flow in low permeability oilfield. Sci Techn Rev, 29(22): 42–44
Li Z C, Li M, Jiang Y J (2013a). A New method for determining gas threshold pressure gradient in low-permeability rock. J Southwest Petrol U (Nat Sci Ed), 35(03): 105–110
Li B, Tang H, Lv D L (2013b). Study on pressure gradient and producing degree of water flooding reserves in square inverted nine-spot well pattern. Lithologic Reservoirs Efficiency, 25(2): 95–99
Miller J, Jones R (1981). A laboratory study to determine Physical Characteristics of Heavy Oil after CO2 Saturation. In: SPE/DOE Enhanced Oil Recovery Symposium. Society of Petroleum Engineers
Mehrotra A K, Svrcek W Y (1982). Correlations for properties of bitumen saturated with CO2, CH4 and N2, and experiments with combustion gas mixtures. J Can Pet Technol, 21(6): 95–104
Shu (1982). Viscosity correlation for mixtures of heavy oil, bitumen, and petroleum fractions. Soc Petrol Eng J, SPE-11280, (1): 277–282
Sun L J, Wu F, Zhao W H, Zhao L J (1998). The Study and application of reservoir start-up pressure. Exploration & Development Science Institute, ZPEB, (05): 30–33
Song F Q, Liu C Q (1999). Two-phase flow analysis of reservoir with starting pressure gradient. J U Petrol, (03): 60–63+69
Sun M R, Zhang X, Geng H Z (2003). Experimental study on viscosity variation of crude oil in oil-water contact pro-cess. J China U Petrol, (02): 63–66+5-4
Si D H (2006). How state distribution of areal radial flow in low permeability sandstone reservoir. Pet Explor Dev, (04): 491–494
Sun J F (2010). Threshold pressure gradient study on non-Newtonian flow of heavy oil reservoirs in Shengli Oilfield. Petrol Geol Recove Efficiency, 17(06): 74–77+116
Welker L R, Dunlop D D (1963). Physical properties of carbonated oils. JPT, 873–75. Trans, AIME: 228
Wang L S, Guo T M (1989). Study on heavy oil viscosity reduction by injection carbon dioxide. Pet Explor Dev, (06): 72–77
Wang L S, Guo T M (1994). High pressure viscosity measurement of Jianhan oil reservoir oil and its carbon dioxide injected system. J China U Petrol (Nat Sci Ed), (04): 125–130
Wang Y F, Wu G, An S K, Zhao W, Jin H (2006). Experimental study on influencing factors of start-up pressure gradient of permeability rocks. J Petrol Nat Gas, (03): 112–113+446
Wang Y N, Wu X D, Zhang S B, Lai F P, Teng M (2013). Experiment and effect evaluation of CO2 immiscible displacement in Extra-low permeability reservoirs. J Oil Gas Techn, 35(04): 136–140+169
Wang X D, Luo W J, Hou X C, Wang J L (2014). Transient pressure analysis of multiple-fractured horizontal well in boxed reservoirs. Petrol Explor Develop, 41(01): 74–78+94
Wen X, Liu Y T, Tian S B, Liu Y F, Liu B (2015). Injection-production parameters optimization of CO2 flooding in extra-low permeability reservoir. J Shaanxi U Sci Techn (Nat Sci Ed), 33(03): 116–120+134
Xu J H, Cheng L S, Zou Y, Ma L L (2007). A new method for calculating kick off pressure gradient in low permeability reservoirs. Petrol Explor Develop, (05): 594–597+602
Xiong W, Lei Q, Liu X G, Gao S S, Hu Z M, Xue H (2009). Pseudo threshold pressure gradient to flow for low permeability reservoirs. Pet Explor Dev, 36(02): 232–236
Yang Y D, Wei D M, Li M L (2010). Study on reasonable well spacing optimization of low permeability and low grade reservoir. J Oil Gas Techn, 32(03): 353–356
Yang J (2011). Research and application on non-Darcy flow theorial model for CO2 flooding. The Dissertation for Doctoral Degree. Daqing: Northeast Petroleum University
Ying L A (2012). The mathematical modeling of black oil. Mathe Model App, 1(04): 1–4
Zhao G Z (2006). Numerical simulation of 3D and three-phase flow with variable start-up pressure gradient. Acta Petrolei Sinica(S1): 119–123+128
Zhang D L, Wang X H, Song Y (2006). Numerical simulation of pinnate horizontal well for coal-bed gas development in consideration of start-up pressure gradient. Acta Petrol Sin, (04): 89–92
Zhang P, Zhang L Z, Li W Y, Wang Y F (2008). Experimental on the influence of boundary layer on the low non-Darcy seepage law. J Hebei U Eng(Nat Sci Ed), (03): 70–72
Zhang X S, Xie X Q, Chen M F (2011). Study on reasonable spacing in low permeability and fault block reservoir. Petrol Geo Recovery Efficiency, 18(6): 94–96
Acknowledgments
Parts of this work were supported by the Dongying Science Development Fund Project (Nos. DJ2022009 and DJ2020003), the Shandong Provincial Higher Education Research and Development Program (Science and Technology A Class) (No. J18KA201), the High-level Talent Research Start-up Fund of Shengli College of China University of Petroleum (No. KQ2019-008), the Chunhui Project of Shengli College of China University of Petroleum (No. KY2017004) and the Research Cultivation Project of College of Big Data and Basic Science of Shandong Institute of Petroleum and Chemical Technology (No. XYPY2201) which supports are appreciated. We also thank all editors and anonymous reviewers for their comments and suggestions.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests The authors declare that they have no competing interests.
Rights and permissions
About this article
Cite this article
Chi, J., Ju, B., Chen, W. et al. Laboratory simulation of CO2 immiscible gas flooding and characterization of seepage resistance. Front. Earth Sci. 17, 797–817 (2023). https://doi.org/10.1007/s11707-022-1074-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11707-022-1074-2