none 10.1190/INT-2018-0239.1 Society of Exploration Geophysicists Society of Exploration Geophysicists 186 109074938 226307 2025120913184685600 10.1190 2025-12-09T18:19:01Z 2019-08-14T02:30:42Z 9 Interpretation 2324-8858 2324-8866 11 1 2019 7 4 Qinhong Hu State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development 1 , Research Institute of Petroleum Exploration and Production, Sinopec, Beijing 100083, and , Department of Earth and Environmental Sciences, 500 Yates Street, Arlington, Texas 76019, . E-mail: maxhu@uta.edu (corresponding author). China USA The University of Texas at Arlington 1 , Research Institute of Petroleum Exploration and Production, Sinopec, Beijing 100083, and , Department of Earth and Environmental Sciences, 500 Yates Street, Arlington, Texas 76019, . E-mail: maxhu@uta.edu (corresponding author). China USA Richard Kalteyer The University of Texas at Arlington 2 , Department of Earth and Environmental Sciences, 500 Yates Street, Arlington, Texas 76019, . E-mail: richardkalteyer@gmail.com . USA Jingyi Wang China University of Geosciences 3 , Key Laboratory of Tectonics and Petroleum Resources, Ministry of Education, Wuhan 430074, . E-mail: jingyi_w008@163.com . China Hesham F. El-Sobky ConocoPhillips 4 , Petrophysics and Reservoir Quality, Exploration, Subsurface and Other International, Houston, Texas 77079, . E-mail: hesham.f.el-sobky@conocophillips.com . USA Abstract The Mancos Shale of the San Juan Basin has been an important resource for the exploration and development of oil and gas. However, as with most unconventional plays, the shales have low porosity and extremely low permeability with predominantly nanometer-sized pores. Thus, it is critical to understand the nanopetrophysical properties of the reservoir so a proper assessment of the reservoir quality can be made. Working with three as-received core samples from three different wells of the Tacito Marine Bar and Offshore Mancos play types, we have developed an initial understanding of the nanopetrophysical properties of the pore structure as well as fluid-rock interactions in these tight reservoirs. We have performed a suite of integrated tests, such as mercury intrusion porosimetry (MIP), low-pressure nitrogen physisorption, core plug porosity and permeability, scanning electron microscopy imaging, water immersion porosimetry after vacuum pulling, contact angle, and fluid imbibition. In addition, we obtained supplementary data for total organic carbon, X-ray diffraction, and pyrolysis to further evaluate reservoir quality. The Mancos Shale samples exhibit petrophysical characteristics that are controlled by a predominant presence of nanometer-sized pore space, with 56%–96% pore volumes present as 3.4–50 nm in pore-throat sizes, as shown by the MIP approach. Contact angle and fluid imbibition tests demonstrate that samples are oil wet to mixed wet, with a tendency of pore networks to imbibe oil over water. The findings from integrated pore structure and wettability studies provide a database and some insights, from the perspectives of nanopetrophysical characterization, into the reservoir quality of the Mancos Shale. 09 20 2019 11 1 2019 08 13 2019 SJ45 SJ65 1 10.1190/crossmark-policy library.seg.org true 2019-01-29 2019-06-20 2019-07-17 2019-09-20 Foundation of State Key Laboratory of Shale Oil Gas Enrichment Mechanisms and Effective Development G5800-17-ZS-KFGY008 10.1190/INT-2018-0239.1 https://pubs.geoscienceworld.org/interpretation/article/7/4/SJ45/574097/Nanopetrophysical-characterization-of-the-Mancos https://pubs.geoscienceworld.org/seg/interpretation/article-pdf/7/4/SJ45/4931193/int-2018-0239.1.pdf https://pubs.geoscienceworld.org/seg/interpretation/article-pdf/7/4/SJ45/4931193/int-2018-0239.1.pdf https://pubs.geoscienceworld.org/interpretation/article/7/4/sj45/574097/nanopetrophysical-characterization-of-the-mancos AIME Amott 216 156 1960 Observations relating to the wettability of porous rock 0022-3522 Journal of Petroleum Technology Anderson 38 1246 1986 10.2118/13933-PA Wettability literature survey — Part 2: Wettability measurement 0002-7863 Journal of the American Chemical Society Barrett 73 373 1951 10.1021/ja01145a126 The determination of pore volume and area distributions in porous substances — 1. Computations from nitrogen isotherms Broadhead R. F. , 2013, The Mancos Shale and “Gallup” zones in the San Juan Basin: Geologic framework, historical production, future potential: San Juan Basin Energy Conference. Broadhead 2015 The Upper Mancos Shale in the San Juan Basin: Three plays, conventional and unconventional Geology of Southwestern San Juan Basin Budd 121 1957 Craigg 4 1971 Geologic framework of the San Juan structural basin of New Mexico, Colorado, Arizona, and Utah with emphasis on Triassic through Tertiary rocks Crowe C. W. , 1969, Methods of lessening the inhibitory effects to fluid flow due to the presence of solid organic substances in a subterranean formation: U.S. Patent 3,482,636. Petroleum reservoir rock and fluid properties Dandekar 2nd ed. 2013 10.1201/b15255 American Journal of Science Dane 258A 46 1960 The boundary between rocks of Carlisle and Niobrara age in San Juan Basin, New Mexico and Colorado Energy and Fuels Dehghanpour 26 5750 2012 10.1021/ef3009794 Liquid intake of organic shales 0149-1423 AAPG Bulletin Emmendorfer 73 1989 Structural influences in Gavilian Mancos oil pool: Fractures, dolomitization, mineralization 0043-1397 Water Resources Research Ewing 38 21-1 2002 10.1029/2002WR001412 Diffusion in sparsely connected pore spaces: Temporal and spatial scaling Fassett 2010 Oil and gas fields of the four corners area Fassett 464 1978 10.2118/166284-MS Gamero-Diaz H. Miller C. Lewis R. , 2012, sCore: A classification scheme for the organic mudstones based on bulk mineralogy: AAPG Southwest Section Meeting. Journal of Geophysical Engineering Gao 10 2013 Estimating permeability using median pore-throat radius obtained from mercury intrusion porosimetry 0149-1423 AAPG Bulletin Gao 100 101 2016 10.1306/09141514095 Wettability of Mississippian Barnett Shale samples at different depths: Investigations from directional spontaneous imbibition International Journal of Coal Geology Gentzis 113 64 2013 10.1016/j.coal.2012.09.006 A review of the thermal maturity and hydrocarbon potential of the Mancos and Lewis Shales in parts of New Mexico, USA Particle and Particle Systems Characterization Giesche 23 9 2006 10.1002/ppsc.200601009 Mercury porosimetry: A general (practical) overview 0001-1541 AICHE Journal Gommes 55 2000 2009 10.1002/aic.11812 Practical methods for measuring the tortuosity of porous materials from binary or gray-tone tomographic reconstructions Hager J. , 1998, Steam drying of porous media: Ph.D. thesis, Lund University. Hu Q. H. Clarke J. J. Baird R. Ostrander C. Gao Z. Y. Zhang Y. X. Kibria G. , 2015a, Correlation of compositional phases and wettability-based fluid-tracers in rock: International Symposium of the Society of Core Analysts, SCA, 2015-057. 0169-7722 Journal of Contaminant Hydrology Hu 133 76 2012 10.1016/j.jconhyd.2012.03.006 Pore connectivity in natural rock Journal of Geophysical Research: Solid Earth Hu 120 8073 2015 10.1002/2015JB012103 Low nanopore connectivity limits gas production in Barnett formation 0022-1694 Journal of Hydrology Hu 242 64 2001 10.1016/S0022-1694(00)00388-7 Laboratory measurement of water imbibition into low-permeability welded tuff Critical Reviews in Environmental Science and Technology Hu 33 275 2003 10.1080/10643380390814488 Aqueous-phase diffusion in unsaturated geological media: A review Petroleum Exploration and Development Hu 44 720 2017 10.1016/S1876-3804(17)30083-6 Characterization of multiple micro-nano pore networks in shale oil reservoirs of Paleogene Shahejie Formation in Dongying Sag of Bohai Bay Basin, East China 10.3133/ofr87450B Huffman C. A. , 1987, Petroleum geology and hydrocarbon plays of the San Juan Basin petroleum system: U.S. Geological Survey, Open-File Report No. 87-450B, 38–46. Percolation theory for flow in porous media Hunt 3rd ed. 2014 10.1007/978-3-319-03771-4 Jarvie D. Claxton B. Henk F. Breyer J. , 2001, Oil and shale gas from the Barnett Shale, Fort Worth Basin, Texas: AAPG Annual Meeting Program, 10, A100. Shale reservoirs — Giant resources for the 21st century Jarvie 89 2012 10.2118/175105-MS Jin G. D. Gonzale P. H. Al Dhamen A. A. Ali S. S. Nair A. Agrawal G. Khodja M. R. Hussaini S. R. Jangda Z. Z. Ali A. Z. , 2015, Permeability measurement of organic-rich shale — Comparison of various unsteady-state methods: Annual Technical Conference and Exhibition, SPE, 175105–MS. Just B. Lloyd R. Anderson R. , 2013, Emerging oil and gas development in Northwestern New Mexico, Horizontal Gallup/Mancos Play: U.S. Department of the Interior, Indian Affairs, Division of Energy and Mineral Development, https://www.bia.gov/cs/groups/xieed/documents/document/idc1-026005.pdf, accessed 10June2019. Kalteyer R. , 2017, Nanopetrophysics characterization of the Mancos Shale Formation in the San Juan Basin of Northwestern New Mexico, U.S.A.: M.S. thesis, The University of Texas at Arlington. Water Resources Research Kao 32 55 1996 10.1029/95WR02974 Prediction of wetting front movement during one-dimensional infiltration into soils Physics Review B Katz 34 8179 1986 10.1103/PhysRevB.34.8179 Quantitative prediction of permeability in porous rock Journal of Geophysical Research: Solid Earth Katz 92 599 1987 10.1029/JB092iB01p00599 Prediction of rock electrical conductivity from mercury injection measurements 1539-3755 Physical Review E Kiepsch 93 2016 10.1103/PhysRevE.93.043128 Interplay of vapor adsorption and liquid imbibition in nanoporous Vycor glass Klinkenberg 200 1941 The permeability of porous media to liquids and gases: Drilling and production practices Organic Geochemistry Löhr 87 119 2015 10.1016/j.orggeochem.2015.07.010 Is organic pore development in gas shales influenced by the primary porosity and structure of thermally immature organic matter? 0149-1423 AAPG Bulletin Loucks 96 1071 2012 10.1306/08171111061 Spectrum of pore types and networks in mudrocks and a descriptive classification for matrix-related mudrock pores Journal of Sedimentary Research Loucks 79 848 2009 10.2110/jsr.2009.092 Morphology, genesis, and distribution of nanometer-scale pores in siliceous mudstones of the Mississippian Barnett Shale Oil and gas fields of the four corners area Matheny 256 1983 Journal of Petroleum Science and Engineering Mokhtari 133 496 2015 10.1016/j.petrol.2015.05.024 Characterization of anisotropy in the permeability of organic-rich shales 10.56577/FFC-25.251 Molenaar C. M. , 1974, Correlation of the Gallup Sandstone and associated formations, upper cretaceous, eastern San Juan and Acoma Basins, New Mexico, in Ghost Ranch, central-northern New Mexico: New Mexico Geological Society Guidebook to 25th Field Conference, 251–258. 10.56577/FFC-28.159 Molenaar C. M. , 1977, Stratigraphy and depositional history of upper cretaceous rocks of the San Juan Basin area, New Mexico and Colorado, with a note of economic resources: New Mexico Geological Society, Guidebook, 28th Field Conference, 159–166. 0149-1423 AAPG Bulletin Montgomery 84 1247 2000 Advanced reservoir characterization to evaluate carbon dioxide flooding, Spraberry Trend, Midland Basin, Texas 0022-3522 Journal of Petroleum Technology Morrow 42 1476 1990 10.2118/21621-PA Wettability and its effect on oil recovery 10.2118/169033-MS Morsey S. Gomma A. Sheng J. J. , 2014, Improvement of Mancos Shale oil recovery by wettability alteration and mineral dissolution: Improved Oil Recovery Symposium, SPE, 169033–MS. Natural Gas Intelligence (NGI), 2019, Shale daily: Information of the San Juan Basin, http://www.naturalgasintel.com/sanjuaninfo, accessed 10June2019. 0008-6223 Carbon Neimarka 47 1617 2009 10.1016/j.carbon.2009.01.050 Quenched solid density functional theory and pore size analysis of micro-mesoporous carbons AAPG Bulletin Peters 70 318 1986 Guidelines for evaluating petroleum source rock using programmed pyrolysis The petroleum system: From source to trap Peters 93 1994 Soil Science Philip 84 257 1957 10.1097/00010694-195709000-00010 The theory of infiltration: 4. Sorptivity and algebraic infiltration equations 0149-1423 AAPG Bulletin Pommer 99 1713 2015 10.1306/03051514151 Pore types and pore-size distributions across thermal maturity, Eagle Ford Formation, southern Texas Reed R. M. Ruppel S. C. , 2014, Variability in organic-matter pore development over depth: A case study from the Devonian-Mississippian Woodford Formation, Delaware Basin, West Texas: Presented at the AAPG Annual Convention and Exhibition. Ridgley 2013 Geology and oil and gas assessment of the Mancos-Menefee composite total petroleum system, San Juan Basin, New Mexico and Colorado, Chap. 4 of U.S. Geological Survey San Juan Basin Assessment Team, total petroleum systems and geologic assessment of undiscovered oil and gas resources in the San Juan Basin Province, exclusive of Paleozoic rocks, New Mexico and Colorado Robinson-Avila K. , 2013, Prospects good for New Mexico oil, gas boom: Albuquerque Journal, https://www.abqjournal.com/181599/prospects-good-for-nm-oil-gas-boom.html, accessed 10June2019. Adsorption by powders and porous solids: Principles, methodology, and applications Rouquerol 1998 Oil and gas fields of the four corners area Sabins 213 1983 Geology of Southwestern San Juan Basin Silver 128 1957 0033-4545 Pure and Applied Chemistry Sing 57 603 1985 10.1351/pac198557040603 Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity Sonnenberg 2011 The Niobrara petroleum system, a major tight resource play in the Rocky Mountain region Introduction to percolation theory Stauffer 2nd ed. 1994 10.2118/162236-MS Sulucarnain I. D. Sondergeld C. H. Rai C. S. , 2012, An NMR study of shale wettability and effective surface relaxivity: Canadian Unconventional Resources Conference, SPE, doi: http://dx.doi.org/10.2118/162236-MS. Hydrology and Earth System Sciences Discussions Tanikawa 3 1315 2006 Klinkenberg effect for gas permeability and its comparison to water permeability for porous sedimentary rocks 10.2118/178568-MS Teklu T. W. Alameri W. Kazemi H. Graves R. M. , 2015, Contact angle measurements on conventional and unconventional reservoir cores: Unconventional Resources Technology Conference, SPE-178568-MS/URTeC: 2153996. Water Resources Research Tokunaga 37 287 2001 10.1029/2000WR900242 Surface-zone flow along unsaturated rock fractures 10.2118/162737-MS Torsæter M. Vullum P. W. Nes O.-M. , 2012, Nanostructure vs. macroscopic properties of Mancos Shale: Canadian Unconventional Resources Conference, SPE, 162737–MS. United States Geological Survey (USGS) 147 2002 Assessment of undiscovered oil and gas resources of the San Juan Basin Province of New Mexico and Colorado Scientific Reports Wang 6 2016 Confinement correction to mercury intrusion capillary pressure of shale nanopores Geochemistry in petroleum exploration Waples 1985 10.1007/978-94-009-5436-6 Proceedings of National Academy of Sciences of the United States of America Washburn 7 115 1921 10.1073/pnas.7.4.115 Note on a method of determining the distribution of pore sizes in a porous material An introduction to the physical characterization of materials by mercury intrusion porosimetry with emphasis on reduction and presentation of experimental data Webb 2001 Journal of Earth Science Wood 28 737 2017 Characterization of organic-rich shales for petroleum exploration and exploitation: A review — Part 1: Bulk properties, multi-scale geometry and gas adsorption Journal of Earth Science Wood 28 758 2017 10.1007/s12583-017-0733-9 Characterization of organic-rich shales for petroleum exploration and exploitation: A review — Part 2: Geochemistry, thermal maturity, isotopes and biomarkers Energy and Fuels Xu 28 4362 2014 10.1021/ef500428y Advances in understanding wettability of gas shales Energy and Fuels Yang 31 6903 2017 10.1021/acs.energyfuels.7b00843 Spontaneous imbibition of three leading shale formations in the Middle Yangtze Platform, South China Fuel Zargari 153 110 2015 10.1016/j.fuel.2015.02.072 Porosity evolution in oil-prone source rocks