Experimental Quantification of the Effect of Thermal Maturity of Kerogen on Its Wettability
- Archana Jagadisan (University of Texas at Austin) | Zoya Heidari (University of Texas at Austin)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- November 2019
- Document Type
- Journal Paper
- 1,323 - 1,333
- 2019.Society of Petroleum Engineers
- kerogen, organic-rich mudrocks, thermal maturity, wettability
- 12 in the last 30 days
- 150 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 12.00|
|SPE Non-Member Price:||USD 35.00|
Kerogen is often considered to be fully hydrocarbon-wet in reservoir characterization. However, wettability of kerogen is not well-understood and quantified. Thermal maturation induces changes in the chemical structure of kerogen and alters its oxygen (O) and hydrogen (H) content. This process affects the surface properties of kerogen and can influence its wettability. Assumptions made regarding the wettability of kerogen affect the interpretation of borehole geophysical measurements such as electromagnetic measurements. Therefore, it is important to quantify the wettability of kerogen as a function of its thermal maturity. The objectives of this research are to experimentally quantify the wettability of kerogen at different thermal-maturity levels and to quantify the influence of chemical composition of kerogen on its wettability. To achieve these objectives, kerogen was first isolated from organic-rich mudrock samples from two different formations at different thermal-maturity levels. The extracted kerogen samples were then synthetically matured. Variations in the composition and chemical-bonding state of carbon (C) present in kerogen at different levels of natural and synthetic thermal maturity were determined using X-ray photoelectron spectroscopy (XPS). The sessile drop method was used to measure the contact angle to quantify the wettability of kerogen. We then investigated the effects of thermal maturity and chemical composition/bonding of kerogen on its wettability.
Kerogen samples from two organic-rich mudrock formations (Formations A and B) were tested, and it was demonstrated experimentally that the wettability of kerogen varies with thermal maturity. Kerogen from Formation A at low thermal maturity formed a 44° air/ water-contact angle and 110° air/oil-contact angle. However, at higher thermal maturities (heat treated at 650°C), the air/water-contact angle increased to 122°, and the oil droplet completely spreads on the kerogen sample. The results suggest that kerogen is oleophilic and hydrophobic at high thermal maturity and hydrophilic at low thermal maturity. The air/water-contact angles in kerogen samples were also recorded after the removal of bitumen generated during synthetic maturation of kerogen using chloroform. The air/water contact angle was shown to increase from 44 to 90° and from 111 to 125° with an increase in thermal maturity in Formations A and B, respectively, in the absence of bitumen. Thus, kerogen becomes hydrophobic with increasing thermal maturity in both the presence and absence of bitumen. The outcomes of this study can potentially improve the formation evaluation of organic-rich mudrocks, in addition to improving our understanding of fluid-flow mechanisms in unconventional reservoirs.
|File Size||601 KB||Number of Pages||11|
Baskin, D. K. 1997. Atomic H/C Ratio of Kerogen as an Estimate of Thermal Maturity and Organic Matter Conversion. AAPG Bull 81 (9): 1437–1450. https://doi.org/10.1306/3B05BB14-172A-11D7-8645000102C1865D.
Bigelow, W. C., Pickett, D. L., and Zisman, W. A. 1946. Oleophobic Monolayers: I. Films Adsorbed From Solution in Non-Polar Liquids. J Colloid Sci 1 (6): 513–538. https://doi.org/10.1016/0095-8522(46)90059-1.
Chalmers, G. R. and Bustin, M. R. 2010. The Effects and Distribution of Moisture in Gas Shale Reservoir Systems. Presented at the AAPG Annual Convention and Exhibition, New Orleans, 11–14 April.
Craddock, P. R., Le Doan, T. V., Bake, K. et al. 2015. Evolution of Kerogen and Bitumen During Thermal Maturation via Semi-Open Pyrolysis Investigated by Infrared Spectroscopy. Energy Fuels 29 (4): 2197–2210. https://doi.org/10.1021/ef5027532.
Dabidian, N., Heidari, Z., and Yang, A. 2016, Quantifying the Impact of Thermal Maturity on Dielectric Permittivity of Pure Kerogen in Organic-Rich Mudrocks. Presented at the SPE/AAPG/SEG Unconventional Resources Technology Conference, San Antonio, Texas, 1–3 August. URTEC-2460670-MS. https://doi.org/10.15530/URTEC-2016-2460670.
Donaldson, E. C., Thomas, R. D., and Lorenz, P. B. 1969. Wettability Determination and Its Effect on Recovery Efficiency. SPE J. 9 (1): 13–20. SPE-2338-PA. https://doi.org/10.2118/2338-PA.
Duan, D., Zhang, D., Ma, X. et al. 2018. Chemical and Structural Characterization of Thermally Simulated Kerogen and Its Relationship With Microporosity. Marine & Pet Geol 89: 4–13. https://doi.org/10.1016/j.marpetgeo.2016.12.016.
Durand, B. and Nicaise, G. 1980. Procedures for Kerogen Isolation. In Kerogen, 35–53. Paris: Éditions Technip.
Harrison, T. M., Armstrong, R. L., Naeser, C. W. et al. 1979. Geochronology and Thermal History of the Coast Plutonic Complex, Near Prince Rupert, British Columbia. Can Jour Earth Sci 16 (3): 400–410. https://doi.org/10.1139/e79-038.
Hu, Y., Devegowda, D., and Sigal, R. 2016. A Microscopic Characterization of Wettability in Shale Kerogen With Varying Maturity Levels. J Nat Gas Sci Eng 33 (July): 1078–1086. https://doi.org/10.1016/j.jngse.2016.06.014.
Jagadisan, A. and Heidari, Z. 2017. Application of X-Ray Photoelectron Spectroscopy in Connecting Thermal Maturity of Kerogen to Its Dielectric Constant in Organic-Rich Mudrocks. Presented at the SPWLA 58th Annual Logging Symposium, Oklahoma City, Oklahoma, 17–21 June. SPWLA-2017-VVVV.
Jagadisan, A. and Heidari, Z. 2018. Impacts of Geochemical Properties on Wettability of Kerogen and Organic-Rich Mudrocks. Presented at the SPE/AAPG/SEG Unconventional Resources Technology Conference, Houston, 22–25 July. URTEC-2902155-MS. https://doi.org/10.15530/URTEC- 2018-2902155.
Jagadisan, A., Yang, A., and Heidari, Z. 2017. Experimental Quantification of the Impact of Thermal Maturity on Kerogen Density. Petrophysics 58 (6): 603–612. SPWLA-2017-v58n6a4.
Kelemen, S. R., Afeworki, M., Gorbaty, M. L. et al. 2002. XPS and 15N NMR Study of Nitrogen Forms in Carbonaceous Solids. Energy Fuels 16 (6): 1507–1515. https://doi.org/10.1021/ef0200828.
Kelemen, S. R., Afeworki, M., Gorbaty, M. L. et al. 2007. Direct Characterization of Kerogen by X-Ray and Solid-State 13C Nuclear Magnetic Resonance Methods. Energy Fuels 21 (3): 1548–1561. https://doi.org/10.1021/ef060321h.
Kinghorn, R. R. F. and Rahman, M. 1980. The Density Separation of Different Maceral Groups of Organic Matter Dispersed in Sedimentary Rocks. J Petrol Geol 2 (4): 449–454. https://doi.org/10.1111/j.1747-5457.1980.tb00972.x.
Krishnan, A., Liu, Y.-H., Cha, P. et al. 2005. An Evaluation of Methods for Contact Angle Measurement. Colloids Surf B Biointerfaces 43 (2): 95–98. https://doi.org/10.1016/j.colsurfb.2005.04.003.
Li, Z., Wang, Y., Kozbial, A. et al. 2013. Effect of Airborne Contaminants on the Wettability of Supported Graphene and Graphite. Nat Mater 12 (10): 925–931. https://doi.org/10.1038/nmat3709.
Mane, A. T. and Patil, V. B. 2016. X-Ray Photoelectron Spectroscopy of Nanofillers and Their Polymer Nanocomposites. In Spectroscopy of Polymer Nanocomposites, ed. S. Thomas, D. Rouxel, and D. Ponnamma, Chap. 15, 452–467. Cambridge, Massachusetts: Elsevier.
Mungan, N. 1964. Role of Wettability and Interfacial Tension in Water Flooding. SPE J. 4 (2): 115–123. SPE-705-PA. https://doi.org/10.2118/705-PA.
Neumann, A. W. and Good, R. J. 1979. Techniques of Measuring Contact Angles. In Surface and Colloid Science, Vol. 11: Experimental Methods, ed. R. J. Good and R. R. Stromberg, Chap. 2, 31–91. New York City: Plenum Press.
Passey, Q. R., Bohacs, K., Esch, W. L. et al. 2010. From Oil-Prone Source Rock to Gas-Producing Shale Reservoir—Geologic and Petrophysical Characterization of Unconventional Shale Gas Reservoirs. Presented at the International Oil and Gas Conference and Exhibition in China, Beijing, 8–10 June. SPE-131350-MS. https://doi.org/10.2118/131350-MS.
Pearson, D. B. III. 1981. Experimental Simulation of Thermal Maturation in Sedimentary Organic Matter (Volumes I and II). PhD dissertation, Rice University, Houston (May 1981).
Restagno, F., Poulard, C., Cohen, C. et al. 2009. Contact Angle and Contact Angle Hysteresis Measurements Using the Capillary Bridge Technique. Langmuir 25 (18): 11188–11196. https://doi.org/10.1021/la901616x.
Ruppert, L. F., Sakurovs, R., Blach, T. P. et al. 2013. A USANS/SANS Study of the Accessibility of Pores in the Barnett Shale to Methane and Water. Energy Fuels 27 (2): 772–779. https://doi.org/10.1021/ef301859s.
Saxby, J. D. 1976. Chemical Separation and Characterization of Kerogen From Oil Shale. In Developments in Petroleum Science, Chap. 5, 103–128. New York: Elsevier. https://doi.org/10.1016/S0376-7361(08)70046-3.
Tissot, B. P. and Welte, D. H. 1984. Petroleum Formation and Occurrence. New York: Springer-Verlag.
Tong, J., Han, X., Wang, S. et al. 2011. Evaluation of Structural Characteristics of Huadian Oil Shale Kerogen Using Direct Techniques (Solid-State 13C NMR, XPS, FT-IR, and XRD). Energy Fuels 25 (9): 4006–4013. https://doi.org/10.1021/ef200738p.
Valdes, C. C., Heidari, Z., and Gonzalez, A. 2017. Quantifying the Impacts of Thermal Maturity on Elastic Properties of Kerogen. Presented at the SPWLA 58th Annual Logging Symposium, Oklahoma City, Oklahoma, 17–21 June. SPWLA-2017-E.
Vandenbroucke, M. 2003. Kerogen: From Types to Models of Chemical Structure. Oil Gas Sci Technol 58 (2): 243–269. https://doi.org/10.2516/ogst:2003016.
Van Krevelen, D. W. 1961. Coal. New York: Elsevier Publishing Co.
Wakeham, S. G., Schaffner, C., and Giger, W. 1980. Polycyclic Aromatic Hydrocarbons in Recent Lake Sediments—I. Compounds Having Anthropogenic Origins. Geochim. Cosmochim. Acta 44 (3): 403–413. https://doi.org/10.1016/0016-7037(80)90040-X.
Welte, D. 1973. Recent Advances in Organic Geochemistry of Humic Substances and Kerogen: A Review. In Advances in Organic Geochemistry 1973, ed. B. Tissot and F. Bienner, 3–13. Paris: Éditions Technip.
Wilhelmy, L. 1863. On the Dependence of the Capillarity Constants of the Alcohol on the Substance and Form of the Wetted Solid Body (Ueber die Abhängigkeit der Capillaritäts-Constanten des Alkohols von Substanz und Gestalt des Benetzten Festen Körpers). Annalen der Physik 195 (6): 177–217. https://doi.org/10.1002/andp.18631950602.
Yang, A., Firdaus, G., and Heidari, Z. 2016. Electrical Resistivity and Chemical Properties of Kerogen Isolated From Organic-Rich Mudrocks. Geophysics 81 (6): D643–D655. https://doi.org/10.1190/geo2016-0071.1.
Young, T. 1805. III. An Essay on the Cohesion of Fluids. Philos Trans R Soc Lond 95: 65–87. https://doi.org/10.1098/rstl.1805.0005.
Yuan, Y. and Lee, T. R. 2013. Contact Angle and Wetting Properties. In Surface Science Techniques, ed. G. Bracco and B. Holst, Chap. 1, 3–34. Berlin: Springer-Verlag.
Zhang, T., Ellis, G. S., Ruppel, S. C. et al. 2012. Effect of Organic-Matter Type and Thermal Maturity on Methane Adsorption in Shale-Gas Systems. Org. Geochem. 47 (June): 120–131. https://doi.org/10.1016/j.orggeochem.2012.03.012.