In-situ Fluid Phase Variation along the Thermal Maturation Gradient in Shale Petroleum Systems and Its Impact on Well Production Performance

Abstract

In-situ fluid phase behavior is important in determining hydrocarbon contents and the multiphase flow through shale reservoirs. The gas-to-oil ratio (GOR) has been recognized as a critical indicator of fluid types. However, little is known about the impact of fluid phase variation across the thermal maturity on shale oil/gas production (e.g., estimated ultimate recovery, EUR). According to the specific gravity ratio of oil/gas, the producing GOR was converted and normalized into a mass fraction of gas in total hydrocarbons (M _GOR) to compare North American shale oil/gas plays with Chinese shale oil and hybrid gas-condensate plays. A correlation between M _GOR, the fluid phases, and production data was established to identify five phase stages of flow. M _GOR varies systematically with the different production zones, which shows promise in rapidly indicating the well production performance and high production stages of shale oil/gas plays. The hybrid shale gas condensate index, T _max, and total gas contents were integrated to present the fluid types and maturity of shale gas-condensates, which indicates fluid phase and production variation across thermal evolution. The results offer a unique perspective on the shale oil reservoir producibility based on the impact of GOR on fluid phases and EUR from the dominant global oil/gas plays.

Keywords

shale oil / shale gas / gas condensate / fluid phase / thermal maturity / sweet spots / GOR / EUR

References

[1] Abarghani A, Ostadhassan M, Bubach B, . Estimation of Thermal Maturity in the Bakken Source Rock from a Combination of Well Logs, North Dakota, USA. Marine and Petroleum Geology, 2019, 105: 32-44.

[2] Ahmadi M A, Bahadori A. Bahadori A. Characterization of Shale Oil. Fluid Phase Behavior for Conventional and Unconventional Oil and Gas Reservoirs, 2017, Amsterdam: Elsevier, 483-519.

[3] Bai Y L, Ma Y H. Geology of the Chang 7 Member Oil Shale of the Yanchang Formation of the Ordos Basin in Central North China. Petroleum Geoscience, 2020, 26(2): 355-371.

[4] Butt H J, Kappl M. Normal Capillary Forces. Advances in Colloid and Interface Science, 2009, 146(1/2): 48-60.

[5] Crnkovic-Friis, L., Erlandson, M., 2015. Geology Driven EUR Prediction Using Deep Learning. SPE Annual Technical Conference and Exhibition, September 28–30, 2015, Houston, Texas, USA. https://doi.org/10.2118/174799-MS

[6] Dang W, Zhang J C, Tang X, . Investigation of Gas Content of Organic-Rich Shale: A Case Study from Lower Permian Shale in Southern North China Basin, Central China. Geoscience Frontiers, 2018, 9(2): 559-575.

[7] EIA, 2011. Bakken Formation Oil and Gas Drilling Activity Mirrors Development in the Barnett. 2011 (2 November 2019)

[8] EIA, 2014. Updates to the EIA Eagle Ford Play Maps. 2014 (December 2014)

[9] EIA, 2018. Assumptions to the Annual Energy Outlook 2018: Oil and Gas Supply Module. 2018 (5 April 2018)

[10] Espitalié J, Marquis F, Barsony I. Voorhees K J. Geochemical Logging. Analytical Pyrolysis, 1984, Amsterdam: Elsevier, 276-304.

[11] French K L, Birdwell J E, Lewan M D. Trends in Thermal Maturity Indicators for the Organic Sulfur-Rich Eagle Ford Shale. Marine and Petroleum Geology, 2020, 118: 104459

[12] Fu J H, Li S X, Xu L M, . Paleo-Sedimentary Environmental Restoration and Its Significance of Chang 7 Member of Triassic Yanchang Formation in Ordos Basin, NW China. Petroleum Exploration and Development, 2018, 45(6): 998-1008.

[13] Gaswirth S B, Marra K R. U. S. Geological Survey 2013 Assessment of Undiscovered Resources in the Bakken and Three Forks Formations of the U. S. Williston Basin Province. AAPG Bulletin, 2015, 99(4): 639-660.

[14] Gherabati S A, Browning J, Male F, . The Impact of Pressure and Fluid Property Variation on Well Performance of Liquid-Rich Eagle Ford Shale. Journal of Natural Gas Science and Engineering, 2016, 33 1056-1068.

[15] Gherabati S A, Hamlin H S, Smye K M, . Evaluating Hydrocarbon-in-Place and Recovery Factor in a Hybrid Petroleum System: Case of Bakken and Three Forks in North Dakota. Interpretation, 2019, 7(3): T607-T624.

[16] Gherabati S A, Hammes U, Male F, . Assessment of Hydrocarbon in Place and Recovery Factors in the Eagle Ford Shale Play. SPE Reservoir Evaluation & Engineering, 2018, 21(2): 291-306.

[17] Gong, X. L., McVay, D., Bickel, J., et al., 2011. Integrated Reservoir and Decision Modeling to Optimize Northern Barnett Shale Development Strategies. SPE/IADC Middle East Drilling Technology Conference and Exhibition, May 23–25, 2023, Abu Dhabi, UAE. SPE-149459-MS. https://doi.org/10.2118/149459-ms

[18] Gong, X., Tian, Y., McVay, D. A., et al., 2013. Assessment of Eagle Ford Shale Oil and Gas Resources. SPE Unconventional Resources Conference Canada, November 5–7, 2013, Calgary, Alberta, Canada. SPE-167241-MS. https://doi.org/10.2118/167241-ms

[19] Gullickson, G., Fiscus, K., Cook, P., 2014. Completion Influence on Production Decline in the Bakken/Three Forks Play. SPE Western North American and Rocky Mountain Joint Meeting, April 16–18, 2014, Denver, Colorado, USA. SPE-169531-MS. https://doi.org/10.1016/10.2118/169531-ms

[20] Hackley P C, Cardott B J. Application of Organic Petrography in North American Shale Petroleum Systems: A Review. International Journal of Coal Geology, 2016, 163: 8-51.

[21] Hackley P C, Zhang L X, Zhang T W. Organic Petrology of Peak Oil Maturity Triassic Yanchang Formation Lacustrine Mudrocks, Ordos Basin, China. Interpretation, 2017, 5(2): SF211-SF223.

[22] Han S B, Horsfield B, Zhang J C, . Hydrocarbon Generation Kinetics of Lacustrine Yanchang Shale in Southeast Ordos Basin, North China. Energy & Fuels, 2014, 28(9): 5632-5639.

[23] He, Z. Y., Murray, A., 2019. Top Down Petroleum System Analysis: Exploiting Geospatial Patterns in the Properties of Hydrocarbon Fluids. In: AAPG Annual Convention and Exhibition, AAPG Datapages: Search and Discovery Article #90350

[24] He, Z. Y., Murray, A., 2020. Migration Loss, Lag and Fractionation: Implications for Fluid Properties and Charge Risk. In: AAPG Annual Convention and Exhibition, AAPG Datapages: Search and Discovery Article

[25] He, Z. Y., Xia, D. N., 2017. HC Migration and Trapping in Unconventional Plays. In: AAPG Annual Convention and Exhibition, AAPG Datapages: Search and Discovery Article #90291

[26] Honarpour, M. M., Nagarajan, N. R., Orangi, A., et al., 2012. Characterization of Critical Fluid, Rock, and Rock-Fluid Properties-Impact on Reservoir Performance of Liquid-Rich Shales. SPE Annual Technical Conference and Exhibition, October 8–10, 2012, San Antonio, Texas, USA. SPE-158042-MS. https://doi.org/10.2118/158042-ms

[27] Huang S P, Liu D, Wang Z C, . Genetic Origin of Gas Condensate in Permian and Triassic Strata in the Southern Sichuan Basin, SW China. Organic Geochemistry, 2015, 85: 54-65.

[28] Jarvie D M, Hill R J, Ruble T E, . Unconventional Shale-Gas Systems: The Mississippian Barnett Shale of North-Central Texas as one Model for Thermogenic Shale-Gas Assessment. AAPG Bulletin, 2007, 91(4): 475-499.

[29] Jarvie, D. M., Jarvie, B. M., Weldon, W. D., et al., 2015. Geochemical Assessment of Petroleum in Unconventional Resource Systems. SPE/ AAPG/SEG Unconventional Resources Technology Conference, July 20–22, 2015, San Antonio, Texas, USA. URTEC-2173379-MS. https://doi.org/10.15530/urtec-2015-2173379

[30] Jones R S Jr.. Producing-Gas/Oil-Ratio Behavior of Multifractured Horizontal Wells in Tight Oil Reservoirs. SPE Reservoir Evaluation & Engineering, 2017, 20(03): 589-601.

[31] Katz B J, Lin F. Consideration of the Limitations of Thermal Maturity with Respect to Vitrinite Reflectance, T _max, and other Proxies. AAPG Bulletin, 2021, 105(4): 695-720.

[32] Khoshghadam, M., Khanal, A., Lee, W. J., 2015. Numerical Study of Production Mechanisms and Gas-Oil Ratio Behavior of Liquid-Rich Shale Oil Reservoirs. SPE Annual Technical Conference and Exhibition, 28–30 September 2015, Houston, Texas, USA, SPE-175137-MS. https://doi.org/10.2118/175137-ms

[33] Kissell, F. N., McCulloch, C. M., Elder, C. H., 1973. The Direct Method of Determining Methane Content of Coalbeds for Ventilation Design. US Department of Interior, Bureau of Mines

[34] Ko L T, Loucks R G, Ruppel S C, . Origin and Characterization of Eagle Ford Pore Networks in the South Texas Upper Cretaceous Shelf. AAPG Bulletin, 2017, 101(3): 387-418.

[35] Ko L T, Loucks R G, Zhang T W, . Pore and Pore Network Evolution of Upper Cretaceous Boquillas (Eagle Ford-Equivalent) Mudrocks: Results from Gold Tube Pyrolysis Experiments. AAPG Bulletin, 2016, 100(11): 1693-1722.

[36] Leverett M C. Capillary Behavior in Porous Solids. Transactions of the AIME, 1941, 142(1): 152-169.

[37] Li D L, Li R X, Zhu Z W, . Origin of Organic Matter and Paleo-Sedimentary Environment Reconstruction of the Triassic Oil Shale in Tongchuan City, Southern Ordos Basin (China). Fuel, 2017, 208: 223-235.

[38] Li L, Sheng J J. Nanopore Confinement Effects on Phase Behavior and Capillary Pressure in a Wolfcamp Shale Reservoir. Journal of the Taiwan Institute of Chemical Engineers, 2017, 78: 317-328.

[39] Li Y H, Song Y, Jiang S, . Influence of Gas and Oil State on Oil Mobility and Sweet-Spot Distribution in Tight Oil Reservoirs from the Perspective of Capillary Force. SPE Reservoir Evaluation & Engineering, 2019, 23(3): 824-842.

[40] Li Y H, Song Y, Jiang S, . Tight Reservoir Oiliness Numerical Simulation Based on a Markov Chain Monte Carlo (MCMC) Method: A Case Study of the Upper Triassic Yanchang-6 Formation (T₃ch₆ Fm.) Outcrop of Ordos Basin. Journal of Petroleum Science and Engineering, 2019, 175: 1150-1159.

[41] Li Y H, Xu X Y, Zhang J F, . Hybrid Sedimentary Conditions of Organic-Rich Shales in Faulted Lacustrine Basin during Volcanic Eruption Episode: A Case Study of Shahezi Formation(K₁sh Fm.), Lishu Faulted Depression, South Songliao Basin. Earth Science, 2022, 47(5): 1728-1747

[42] Li Y H, Yang W, Wang Q Y, . Influence of the Actively Migrated Diagenetic Elements on the Hydrocarbon Generation Potential in Tuffaceous Shale. Fuel, 2019, 256: 115795

[43] Lohr C D, Hackley P C. Relating T _max and Hydrogen Index to Vitrinite and Solid Bitumen Reflectance in Hydrous Pyrolysis Residues: Comparisons to Natural Thermal Indices. International Journal of Coal Geology, 2021, 242 103768

[44] Mahmoud, O., Ibrahim, M., Pieprzica, C., et al., 2018. EUR Prediction for Unconventional Reservoirs: State of the Art and Field Case. SPE Trinidad and Tobago Section Energy Resources Conference, June 25–26, 2018, Port of Spain, Trinidad and Tobago. SPE-191160-MS. https://doi.org/10.2118/191160-MS

[45] McCain J, W D. The Properties of Petroleum Fluids, 1990, Tulsa, USA: PennWell Books, PennWell Publishing Company

[46] Mesbah M, Bahadori A. Bahadori A. Equations of State. Fluid Phase Behavior for Conventional and Unconventional Oil and Gas Reservoirs, 2017, Amsterdam: Elsevier, 65-116.

[47] Mullins O C, Daigle T, Crowell C, . Gas-Oil Ratio of Live Crude Oils Determined by Near-Infrared Spectroscopy. Applied Spectroscopy, 2001, 55(2): 197-201.

[48] Murray, A., He, Z., Edwards, C., 2021. Oil by Exception: Where and Why Oil Occurs in the Gassy Petroleum Systems of the NW Shelf of Australia. In: Advanced Petroleum Systems Analysis in the Asia Pacific Region, New Technology and Applications

[49] Nojabaei B, Johns R T, Chu L. Effect of Capillary Pressure on Phase Behavior in Tight Rocks and Shales. SPE Reservoir Evaluation & Engineering, 2013, 16(3): 281-289.

[50] Nojabaei B, Siripatrachai N, Johns R T, . Effect of Large Gas-Oil Capillary Pressure on Production: A Compositionally-Extended Black Oil Formulation. Journal of Petroleum Science and Engineering, 2016, 147: 317-329.

[51] Smith, D. M., Williams, F. L., 1981. New Technique for Determining the Methane Content of Coal. In: Proceedings of the 16th Intersociety Energy Conversion Engineering Conference, American Society of Mechanical Engineers, August 9–14, 1981, Atlanta, GA, USA. 1272–1277

[52] Smith D M, Williams F L. Direct Method of Determining the Methane Content of Coal—A Modification. Fuel, 1984, 63(3): 425-427.

[53] Soeder D J. The Successful Development of Gas and Oil Resources from Shales in North America. Journal of Petroleum Science and Engineering, 2018, 163: 399-420.

[54] Speight J. Speight J. Analysis of Gas and Condensate from Tight Formations. Shale Oil and Gas Production Processes, 2020, Amsterdam: Elsevier, 373-450.

[55] Strąpoć D, Jacquet B, Torres O, . Deep Biogenic Methane and Drilling-Associated Gas Artifacts: Influence on Gas-Based Characterization of Petroleum Fluids. AAPG Bulletin, 2020, 104(4): 887-912.

[56] Swindell, G. S., 2012. Eagle Ford Shale—An Early Look at Ultimate Recovery. SPE Annual Technical Conference and Exhibition, October 8–10, 2012, San Antonio, Texas, USA. SPE-158207-MS. https://doi.org/10.2118/158207-MS

[57] Symcox, C., Philp, R. P., 2019. Heterogeneity of STACK/SCOOP Production in the Anadarko Basin, Oklahoma—Geochemistry of Produced OilsProceedings of the 7th Unconventional Resources Technology Conference. July 22–24, 2019. Denver, Colorado, USA. Tulsa, OK, USA. URTEC-2019-513-MS. https://doi.org/10.15530/urtec-2019-513

[58] Tissot B P, Durand B, Espitalié J, . Influence of Nature and Diagenesis of Organic Matter in Formation of Petroleum. AAPG Bulletin, 1974, 58(3): 499-506

[59] Tissot B P, Pelet R, Ungerer P. Thermal History of Sedimentary Basins, Maturation Indices, and Kinetics of Oil and Gas Generation. AAPG Bulletin, 1987, 71: 1445-1466.

[60] Tohidi-Hosseini S M, Hajirezaie S, Hashemi-Doulatabadi M, . Toward Prediction of Petroleum Reservoir Fluids Properties: A Rigorous Model for Estimation of Solution Gas-Oil Ratio. Journal of Natural Gas Science and Engineering, 2016, 29: 506-516.

[61] Travers, P. D., Cumella, S., Dolan, M., 2014. Using Production Gas Carbon and Hydrogen Stable Isotope Signatures to Predict Fluid Quality: Wattenberg Field, Colorado, USA. SPE Western North American and Rocky Mountain Joint Meeting, April 16–18, 2014, Denver, Colorado, USA. SPE-169487-MS. https://doi.org/10.2118/169487-ms

[62] Wachtmeister H, Lund L, Aleklett K, . Production Decline Curves of Tight Oil Wells in Eagle Ford Shale. Natural Resources Research, 2017, 26(3): 365-377.

[63] Wang M, Tian S S, Chen G H, . Correction Method of Light Hydrocarbons Losing and Heavy Hydrocarbon Handling for Residual Hydrocarbon (S1) from Shale. Acta Geologica Sinica: English Edition, 2014, 88(6): 1792-1797.

[64] Wang Q Y, Li Y H, Yang W, . Finite Element Simulation of Multi-Scale Bedding Fractures in Tight Sandstone Oil Reservoir. Energies, 2019, 13(1): 131

[65] Wang X Z, Peng X L, Zhang S J, . Characteristics of Oil Distributions in Forced and Spontaneous Imbibition of Tight Oil Reservoir. Fuel, 2018, 224: 280-288.

[66] Williams, R. D., Willberg, D. M., Handwerger, D., et al., 2014. Advanced Core Analysis Methodologies Quantify and Characterize Prolific Liquid Hydrocarbon Quantities in the Vaca Muerta Shale. SPE/AAPG/ SEG Unconventional Resources Technology Conference, August 25–27, 2014, Denver, Colorado, USA. URTEC-1922938-MS. https://doi.org/10.15530/urtec-2014-1922938

[67] Yang W, Song Y, Jiang Z X, . Whole-Aperture Characteristics and Controlling Factors of Pore Structure in the Chang 7th Continental Shale of the Upper Triassic Yanchang Formation in the Southeastern Ordos Basin, China. Interpretation, 2018, 6(1): T175-T190.

[68] Yang W, Wang Q Y, Song Y, . New Scaling Model of the Spontaneous Imbibition Behavior of Tuffaceous Shale: Constraints from the Tuff-Hosted and Organic Matter-Covered Pore System. Journal of Natural Gas Science and Engineering, 2020, 81 103389

[69] Yang W, Wang Q Y, Wang Y H, . Pore Characteristic Responses to Categories of Depositional Microfacies of Delta-Lacustrine Tight Reservoirs in the Upper Triassic Yanchang Formation, Ordos Basin, NW China. Marine and Petroleum Geology, 2020, 118 104423

[70] Yang Y T, Li W, Ma L. Tectonic and Stratigraphic Controls of Hydrocarbon Systems in the Ordos Basin: A Multicycle Cratonic Basin in Central China. AAPG Bulletin, 2005, 89(2): 255-269.

[71] Yang Z, Zou C N, Wu S T, . Characteristics, Types, and Prospects of Geological Sweet Sections in Giant Continental Shale Oil Provinces in China. Journal of Earth Science, 2022, 33(5): 1260-1277.

[72] Yee D, Seidle J P, Hanson W B. Gas Sorption on Coal and Measurement of Gas Content. Hydrocarbons from Coal, American Association of Petroleum Geologists, 1993, 38 203-218.

[73] Zhang M A, Ayala L F. Analytical Study of Constant Gas/Oil-Ratio Behavior as an Infinite-Acting Effect in Unconventional Multiphase Reservoir Systems. SPE Journal, 2016, 22(1): 289-299.

[74] Zhang M A, Becker M D, Ayala L F. A Similarity Method Approach for Early-Transient Multiphase Flow Analysis of Liquid-Rich Unconventional Gas Reservoirs. Journal of Natural Gas Science and Engineering, 2016, 28: 572-586.

[75] Zhang T W, Sun X, Milliken K L, . Empirical Relationship between Gas Composition and Thermal Maturity in Eagle Ford Shale, South Texas. AAPG Bulletin, 2017, 101(8): 1277-1307.

[76] Zhang X S, Wang H J, Ma F, . Classification and Characteristics of Tight Oil Plays. Petroleum Science, 2016, 13(1): 18-33.

[77] Zhang Y, Lashgari H R, Di Y, . Capillary Pressure Effect on Phase Behavior of CO₂/Hydrocarbons in Unconventional Reservoirs. Fuel, 2017, 197: 575-582.

[78] Zhao H, Givens N B, Curtis B. Thermal Maturity of the Barnett Shale Determined from Well-Log Analysis. AAPG Bulletin, 2007, 91(4): 535-549.

[79] Zou C N, Yang Z, Li G, . Why Can China Realize the Continental “Shale Oil Revolution”?. Earth Science, 2022, 47(10): 3860-3863