Oil Shale and Shale Gas Technology

Dr. Lee’s group, while at the University of Akron, conducted a pioneering research on oil shale extraction using carbon dioxide as a sweep gas medium, which resulted in a remarkably enhanced recovery of shale oil from oil shale. The technology was awarded a U.S. patent in 1985.

  • S. Lee and R. Joshi, “Enhanced Oil Recovery from Western United States Type Oil Shale Using Carbon Dioxide Retorting Technique”, U.S. Patent No. 4,502,942, March 5, 1985.

The technology was demonstrated on a large variety of worldwide shale samples including Colorado, Ohio Devonian, N. Carolina, Chattanooga, Australian Stewart, Jordanian El-Lajjun , and Israeli shales. It was also proven by the team’s investigation that the enhancement in oil recovery is very significant under both subcritical and supercritical conditions. Recent studies further indicate that the technology is eminently applicable to modern shale gas technologies including the fracking process.

Current R&D interests in the shale fuels area include:

1. On-site Treatment and Reuse of Fracking Flowback Water [as an improvement of the current technology]
2. Enhanced Shale Gas/Oil Recovery Process
3. Waterless Fracking Technology [as an improvement of the current technology]
4. Sand-free Fracking Technology [as an improvement of the current technology]
4. Development of Environmentally Friendly Additives [as an improvement of the current technology]
5. Synthesis of Polymeric Proppants and Gellants
6. Beneficial Use of Caron Dioxide in Extraction Technology
7. Beneficial Pretreatment of Shale Bed for Maximal and Efficient Yield
8. Horizontal Directional Drilling
9. Clay Stabilization and Effective Bed Sustainment
10. Minimal Effect from Disturbance of Brine
11. Exploration of Multi-mineral Strategy
12. Minimization of Above-ground Footprint
13. Leakage Prevention and Control
14. Environmental Benefit Assessment
15. Integration of Carbon Capture Solutions
16. Implementation of Novel Stimulation technologies
17. Retrofitting Ideas
18. Environmentally and Geochemically Safe Shut-off

The current R&D program is currently sponsored by Samwha Solutions USA Inc. and SWS USA LLC.  Once the current R&DD efforts are completed for the novel technology, it would be a game changer in the field.   For serious interest in commercialization and collaborative efforts and/or joining the current development project, please contact us.

 

S. Lee’s Prior Research and Teaching Activities in the Area of
Oil Shale/Shale Oil/Shale Gas Technology

A. Books and Book Chapters on Oil Shale

  1. S. Lee, Author, “Oil Shale Technology,” CRC Press, Boca Raton, FL, ISBN-0-8493-4615-0, 1991. An updated 2nd edition of this book is scheduled for publication in 2013.
  2. S. Lee, Author, “Alternative Fuels,” Taylor & Francis, Washington, D.C., ISBN-1-56032-361-2, 1996. Chapter 7 is “Oil Shale and Shale Oil.”
  3. S. Lee, Author, “Methane and Its Derivatives,” Marcel Dekker, Inc., New York, NY, ISBN-0-8247-9754-X, 1997.
  4. S. Lee, J. G. Speight, and S.K. Loyalka, Co-authors, “Handbook of Alternative Fuel Technologies,” CRC Press, Boca Raton, FL, ISBN: 0-8247-4069-6, FL 2007. Chapter 8 is “Shale Oil from Oil Shale.”
  5. S. Lee, a chapter on “Oil Shale,” in Encyclopedia of Petroleum Science and Engineering, edited by George J. Antos, Taylor & Francis, N.Y., NY, 2007.

B. U.S. Patent Awarded in Oil Shale Extraction Technology

  1. S. Lee and R. Joshi, “Enhanced Oil Recovery from Western United States Type Oil Shale Using Carbon Dioxide Retorting Technique,” U.S. Patent No. 4,502,942, March 5, 1985.

C. Journal Publications in Oil Shale Technology (Co-authors are Lee’s students)

  1. R. Joshi and S. Lee*, “Comparative Study Between the Kinetics of Retorting of Ohio and Colorado Shale,” Liquid Fuels Technology, Vol. 1, pp. 17-34, 1983.
  2. V. Parameswaran, M. E. Polasky, and S. Lee*, “Enhanced Oil Recovery from Pyrolysis of Various Australian Shales,” ACS Fuel Preprint, Vol. 30, No. 3, pp. 286-293, American Chemical Society, Washington, DC (1985).
  3. M. E. Polasky and S. Lee*, “Pyrolysis Kinetics of Various Australian Oil Shales in Nitrogen and Carbon Dioxide Atmospheres,” ACS Fuel Preprint, Vol. 30, No. 3, pp. 294-300, American Chemical Society, Washington, DC (1985).
  4. Y. Wang and S. Lee*, “A Single Particle Model for Pyrolysis of Oil Shale,” Fuel Sci. & Tech. Int’l., Vol. 4, pp. 447-481, 1986.
  5. M. E. Polasky and S. Lee*, “Boiling Range Distributions of Various Shale Oils and Influence of Carbon Dioxide Retorting,” Fuel Sci. & Tech. Int’l., Vol. 6, No. 1, pp. 83-94, 1988.
  6. M. E. Polasky and S. Lee*, “A Slope Method for Characterizing Shale Oils,” Fuel Sci. & Tech. Int’l., Vol. 6, No. 4, pp. 367-379, 1988.
  7. S. Kesavan, A. Ghosh, V. Parameswaran, and S. Lee*, “Supercritical Extraction of Stuart Shale,” Fuel Sci. & Tech. Int’l., 6(5), pp. 505-523, 1988.
  8. M. E. Polasky, S. K. Kesavan, and S. Lee*, “Chemical Compositions of Shale Oil. I. Dependence on Oil Shale Origin,” Fuel Sci. & Tech. Int’l., Vol. 9, No. 8, pp. 1015-1059, 1991.
  9. S. Lee*, K. L. Fullerton and M. E. Polasky, “Chemical Composition of Shale Oil. II. Dependence on Extraction Process,” Fuel Sci. & Tech. Int’l., Vol. 9, No. 9, pp. 1151-1179, 1991.
  10. D. J. Tucker, B. Masri, and S. Lee*, “A Comparison of Retorting and Supercritical Extraction Techniques on El-Lajjun Oil Shale,” Energy Sources, Vol. 22, No. 5, PP. 453-464, 2000.

D. Proceedings Articles in Oil Shale

  1. S. Lee*, M. E. Polasky and R. Joshi, “Pyrolysis Kinetics of Various Eastern Shales in Nitrogen and Carbon Dioxide Atmosphere,” Proceedings of 1983 Eastern Oil Shale Symposium, Vol. 1, pp. 225-233, University of Kentucky Institute of Mining & Minerals Research, Lexington, KY (1983).
  2. J. E. Vamosi and S. Lee*, “Subcritical CO2 Retorting vs. Supercritical CO2 Extraction of Oil Shale,” Proceedings of the Twelfth Annual International Pittsburgh Coal Conference, Vol. 1, pp. 745-749, Pittsburgh, PA, Sept., 11-15, 1995.

E. Conference Papers, Seminars and Short Courses Delivered on Oil Shale Topics

  1. R. Joshi, Y. Wang, and S. Lee*, “Kinetic Study of Eastern Oil Shale Pyrolysis,” paper presented at the 11th Annual Akron Chemists-Chemical Engineers Symposium, Akron, Ohio, 1980.
  2. Invited Seminar on “Eastern Oil Shale Pyrolysis,” Department of Chemical Engineering, University of Kentucky, Lexington, KY, April 6, 1983.
  3. Invited Seminar on “Recent Advances in Synfuel Research”, Kansas State University, Manhattan, KS, May 25, 1983.
  4. J. E. Vamosi, B. S. Kocher, K. L. Fullerton, and S. Lee*, “Supercritical Extraction Product Characterization of Various Oil Shales,” 1993 Eastern Oil Shale Symposium, Lexington, KY., November 16-19, 1993.
  5. H. B. Lanterman, J. E. Vamosi, B. S. Kocher, and S. Lee*, “Supercritical Hydrogen Extraction and Upgrading of Israeli Oil Shale,” Symposium on Supercritical Fluids, AIChE 1994 Annual Meeting, Paper # 118x, San Francisco, CA, Nov., 13-18, 1994.
  6. An invited short course on “Shale Gas Technology,” delivered at Northern Technologies International Corp. (NTIC), Circle Pines, MN, December 12, 2012.

F. Graduate Degree Students Guided in Oil Shale Topics

  1. 1981 Shong-Tai Jeng (M.S., Modeling and Simulation of Oil Shale Retorting Process)
  2. 1982 Yeh Wang (M.S., A Single Particle Model for Pyrolysis of Oil Shale)
  3. 1982 Rajendra Joshi (M.S., Kinetic Study of Eastern Oil Shale Pyrolysis)
  4. 1985 Mark E. Polasky (M.S., Pyrolysis Kinetics and Process Optimization of Eastern United States and Australian Oil Shales)
  5. 1988 Mark E. Polasky (Ph.D., Characterization of Extracted Shale Oil Crudes
  6. 1998 Bassam Masri (Ph.D., Extraction and Characterization of El-Lajjun Jordanian Oil Shale

G. Class Teaching (in Oil Shale Topics)

  1. Alternative Fuels (Missouri University of Science and Technology) F07, S08, F09
  2. Alternative Fuels (Ohio University) S11. F12
  3. Shale Fuels (Ohio University) S12

SWS/CTI’s Oil Shale Technology Narrative

Based on our extensive analysis of global shale samples [1] (such as CONDOR, RUNDLE, STUART, El LAJJUN, COLORADO, NORTH CAROLINA, OHIO DEVONIAN, and CHATTANOGA shales) it has been observed that shale crude oil predominantly exists in a solid or semi-solid state, in contrast to conventional liquid crude oil reservoirs. Unlike conventional oil wells, which contain significant pools of free-flowing liquid hydrocarbons, shale crude oil is distributed in multiple forms and phases within the shale rock matrix. These forms include:

  • Solid hydrocarbons, known as kerogen [2], which consist of high-molecular-weight organic compounds (Mw ~ 3000-5000).
  • Agglomerated hydrocarbons comprised of a mixture/admixture of high- and low-molecular-weight carbonaceous species stuck together.
  • Hydrocarbons that are intimately associated with shale granules and particles (chemisorbed and/or encapsulated), forming a tightly compacted structure.

Due to these characteristics, shale formations must be mechanically fractured and subjected to thermal and/or chemical treatment to enhance hydrocarbon isolation, separation, and mobilization. A small fraction (typically <10%) of the hydrocarbons present in most shale formations comprises of low-molecular-weight compounds, which may exist in solid, semi-solid, or liquid-like states. These hydrocarbons must permeate, ooze or escape through the shale rock’s microporous network, by a process that is inherently challenging due to extremely limited natural porosity and permeability. Consequently, physical recovery methods based on conventional fracking typically yield only a small percentage of the total hydrocarbons present within shale formations. Volumes of literature report 5% to 11% for the shale oil recoverability [3-6].

Our own research data [7] indicate that the chemical compositions of recovered hydrocarbons significantly vary depending on the extraction method applied. More than 500 distinct organic species have been molecularly identified via gas chromatography-mass spectrometry (GC-MS) [8], highlighting the diverse chemical nature of shale-based hydrocarbons. Variations in treatment processes, including thermal treatment, temperature and pressure conditions, and different gas environments (e.g., sweep gas or flooding gas), lead to the production of a great many distinct chemical species. This also indicates that shale hydrocarbons or fragments of these oil shale hydrocarbons are quite readily reactive and/or prone to break down to lower molecular species. In addition to aliphatic and aromatic hydrocarbons, shale oil also contains branched structures and chemically unstable bonds that can be easily cleaved under appropriate conditions, thus resulting in producing more mobile molecules.

Our early investigation of the Ohio Devonian shale in the 1980’s [9a] verified that large amounts of light hydrocarbons (such as methane and ethane) are entrapped within micropores, medium or larger pore structures in the very compact and tight shale matrix. Therefore, increase in permeability becomes a key factor to facilitate moving/escaping those hydrocarbon molecules away from the encasing small pores. Due to the inherently low porosity/permeability of shale, hydrocarbon mobility is very severely restricted. Permeability follows Darcy’s law, indicating that significant increase in pore pass ways is necessary to enhance flow rates, otherwise it would take forever. Modern hydraulic fracturing (fracking) has been employed to induce fragmentation/crushing/rubblization of the shale rocks to smaller pieces, facilitating hydrocarbon release and permeability increase. Based on our experimental observations, light hydrocarbons, such as methane and ethane, are present in shale rock. This is predominant in geologically old oil shale formations such as Utica and Lower Devonian shales. This explains why shale gas is often predominantly composed of methane, forming natural gas. We are the very first who actually observed the existence of natural gas in Ohio Devonian Shale.  Because even with a small temperature increase in the oil shale sample in a chemical  reactor, after it had been excavated from the formation, it generated the distinct sound of popping or crackling that indicates small pores in the sample got broken up due to the volume expansion of the natural gas contained therein [9b]. This observation further supports the existence of light hydrocarbons within the shale matrix, though unlike conventional reservoirs there is no large cave type of a dome for the accumulated natural gas in shale bed, as a result shale bed has to be crushed/fractured into small particle sizes.

Our own research [10] has also demonstrated the efficacy of carbon dioxide (CO₂) as a mobilizing agent (sweep gas) for shale hydrocarbons. When CO2 is used as a sweep gas—even without applying significant pressure—hydrocarbons in oil shale become more mobile and are released in larger quantities. Lee’s earlier U.S. patent [11] for CO2 extraction process for eastern oil shale was based on this phenomenon. Other scientists in later years [12-15] have also verified that kerogen and some hydrocarbon species can dissolve partially into CO2. Because carbon dioxide certainly attracts hydrocarbon molecules due to the nucleophilic nature of its molecule. In well-known CO₂ EOR [16], it facilitates hydrocarbon extraction through mostly physical interactions via volume expansion rather than true solubilization. If the pressure and temperature of CO2 increases, it reaches a supercritical state. However, when CO₂ is brought to its supercritical state—achieved at relatively mild conditions (critical temperature: 31.4°C, critical pressure: 72.9 atm)—its solvent properties are drastically enhanced. Given that subsurface shale formations are under high overburden pressures (6000–8000 psi), achieving supercritical CO₂ conditions in the shale bed is practically effortless. In this state, CO₂ can mostly dissolve hydrocarbons, drastically improving their mobility and recoverability. The effectiveness of supercritical CO₂ treatment can be significantly enhanced using the SWS/CTI [17] technology by synergistically optimizing several key process parameters, including particle size reduction, permeability enhancement, solubility optimization, and treatment stages (chemi-desorption, deagglomeration, surface cleansing and lubrication, and dissolution) and controlled duration.

Our own research findings [18] also suggest that high-molecular-weight hydrocarbons (e.g., up to C70 aliphatic species) exhibit increased mobility at elevated temperatures (~200°C) due to their viscosity reduction. Therefore, optimal management of temperature and pressure within the shale bed could be crucial for maximizing the hydrocarbon recovery. In our current technological development, we have identified a ten-stage advanced process application designed to maximize hydrocarbon recovery efficiency [19]. A key aspect of this approach is the introduction/application of the novel concept of underground refining (in-situ refining), which would involve in-situ pyrolysis facilitated by controlled temperature and pressure conditions, drastically enhanced with selective catalysts. This method would represent the ultimate goal of the futuristic oil recovery, enabling near-complete extraction of all recoverable hydrocarbons. We will assign a numerical value of “10” for the stage then we can define our own parameter of technology application level (TAL). Which would range from “1” through “10”. Our own 10-stage technology enhancement chart can be modified to accommodate this concept.  An increase level in the resultant O&G recoverability by application of advanced treatment processes varies depending upon the shale formation geology and geochemistry, the hydrocarbon molecular profile of crude oil, and the O&G well design specifics. Needless to say, any additional process treatment comes with an added operational cost.  Therefore, a cost-to-benefit analysis needs to be conducted before any Go/No-Go decision can be made.

References

[1] Lee, S. (1991).  Oil Shale Technology. CRC Press.

[2] Lee, S. (1991). Oil Shale Technology. (pp. 17-25). CRC Press.

[3] Seales, M. B., Ertekin, T., & Yilin Wang, J. (2017). Recovery efficiency in hydraulically fractured shale gas reservoirs. Journal of Energy Resources Technology, 139(4), 042901.

[4] Gamadi, T. D., Sheng, J. J., Soliman, M. Y., Menouar, H., Watson, M. C., & Emadibaladehi, H. (2014, April). An experimental study of cyclic CO2 injection to improve shale oil recovery. In SPE Improved Oil Recovery Conference? (pp. SPE-169142). SPE.

[5] Alharthy, N., Teklu, T., Kazemi, H., Graves, R., Hawthorne, S., Braunberger, J., & Kurtoglu, B. (2018). Enhanced oil recovery in liquid–rich shale reservoirs: laboratory to field. SPE Reservoir Evaluation & Engineering, 21(01), 137-159.

[6] Canadian Society of Unconventional Resources. (n.d.). Retrieved March 3, 2025, from http://www.csur.com

[7] Lee, S., Fullerton, K. L., & Polasky, M. E. (1991). Chemical composition of shale oil. II. Dependence on extraction process. Fuel Science and Technology International, 9(9), 1151–1179.

[8] Lee, S. (1991). Oil shale technology (pp. 160–225). CRC Press.

[9a] Lee, S. (1991). Oil shale technology (pp. 30–35). CRC Press.

[9b] Lee, S. (1991). Oil shale technology (pp. 30–35). CRC Press.

[10] Kesavan, S., Ghosh, A., Parameswaran, V., & Lee, S. (1988). Supercritical extraction of Stuart shale. Fuel Science and Technology International, 6(5), 505–523. [https://doi.org/10.1080/08843758808915900]

[11] Lee, S., & Joshi, R. (1985). U.S. patent No. 4,502,942. United States Patent and Trademark Office.

[12] Chevron CRUSH. (n.d.). Wikipedia. Retrieved March 3, 2025, from https://en.wikipedia.org/wiki/Chevron_CRUSH#:~:text=Chevron%20CRUSH%20is%20an%20experimental,the%20Los%20Alamos%20National%20Laboratory

[13] Alfarge, D., & Wei, M. (2017). Factors affecting CO₂-EOR in shale-oil reservoirs: Numerical simulation study and pilot tests. Energy & Fuels, 31(8), 8462–8480. [https://pubs.acs.org/doi/10.1021/acs.energyfuels.7b01623]

[14] Vladimir, D., & Corporation, A. (2018, September 5–6). Advanced formation evaluation to optimize shale development in Permian Basin. In SPE Liquids-Rich Basins Conference – North America. Society of Petroleum Engineers.

[15] Liu, S., & Sahni, V. (2018, July 23–25). Laboratory investigation of EOR techniques for organic-rich shales in the Permian Basin. In SPE/AAPG/SEG Unconventional Resources Technology Conference. Society of Petroleum Engineers.

[16] Dong, C., & Hoffman, B. T. (2013). Modeling gas injection into shale oil reservoirs in the Sanish Field, North Dakota. Society of Petroleum Engineers.

[17] SWS-CTI. (2025, February). Graphical abstract of mechanisms of SWS/CTI Sc-CO₂ technology [PowerPoint slides]. Confidential.

[18] Perez, P. L., Gurnon, A. K., Chichak, K., McDermott, J., de Paulo, J., Peng, W., & Xie, X. (2016, May). Mitigating wax deposition from crude oils: correlations between physical-chemical properties of crude oils and the performance of wax inhibitors. In Offshore Technology Conference (p. D011S004R002). OTC. https://doi.org/10.4043/27255-MS

[19] SWS-CTI. (2024, October). Investment promotion – 3 talks [PowerPoint slides]. pp. 18–19.