Multiscale Imaging of Gas Adsorption in Shales
Transcript of Multiscale Imaging of Gas Adsorption in Shales
Multiscale Imaging of Gas Adsorption in Shales
Hamza Aljamaan, Cynthia M. Ross, Anthony R. Kovscek
SCCS Annual Affiliate Meeting 2017
May 25st 2017
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1. The problem…
What I’m going to talk about….
2. Methodology
4. Conclusions3. Results
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5×2.5 cmParticle
Powder
Intact Core
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Hale, B. W., & Hall, R. K. (2017, February). Historical Terminal Decline Rates Review of Unconventional Reservoirs
in the United States. In SPE Unconventional Resources Conference. Society of Petroleum Engineers.
Production Profile
Recovery Factor ~ 10-20%
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Walker, G., Branter, T., & Miller, P. (2017, February). Adsorbed Gas Composition, and its Impact on Early Time
Production. In SPE Unconventional Resources Conference. Society of Petroleum Engineers.
Total Gas (𝝃) = Adsorbed Gas + Free Gas (ф)
Gas Storage Capacity and Distribution
• Volumetric experimental data reveal the potential of CO2 storage in shale
Barnett 26-Ha
Pore Pressure = 804 psia Barnett #26 Haynesville GU 1-2
Free Gas (scf/ton) 40.9 70.6
CH4 Adsorbed Gas (scf/ton) 24.5 38.2
CO2 Adsorbed Gas (scf/ton) 235.8 631.8
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Aljamaan, H., Al Ismail, M., & Kovscek, A. R. (2016). Experimental investigation and Grand Canonical Monte
Carlo simulation of gas shale adsorption from the macro to the nano scale. Journal of Natural Gas Science and
Engineering.
CO2 Adsorbed vs. Free gas
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Barnett 26-Ha Eagle Ford EF-4 Haynesville TWG3-2 Permian P-2
Source Sample Depth (ft) Ro TOC Clays Carbonates Quartz Feldspar Pyrite
Barnett 26-Ha 8620.1 - 11.7* 25.2 10.4 45.1 5.8 1.7
Eagle Ford EF-4 11184.8 1.39 5.1 20.3 48.9 18 3.8 3.9
Haynesville TWG3-2 11134.05 1.37 1.9 22.8 49.5 16.8 6.9 2.0
Permian+ P-2 10134.25 1.28 0.5 5.5 68.8 17.5 7.3 1.0
Study Samples
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Gas Adsorption Imaging
GE HiSpeed CT/I fifth generation medical scanner operated in helical mode
Voxel size: 0.19 ˣ 0.19 ˣ 1 mm
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𝜉 =𝐶𝑇 𝑔 𝑟 − 𝐶𝑇 𝑎 𝑟
𝐶𝑇𝑔𝑎𝑠 − 𝐶𝑇𝑣𝑎𝑐𝑢𝑢𝑚
Storage Capacity (𝝃) = Adsorbed Gas + Free Gas (ф)
Gas Adsorption Imaging
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Kr
CO2
Barnett Eagle Ford Haynesville Permian
5.6
10.2
9.9
12.8 17.5
11.0
14.4
7.8
Kr vs CO2 Storage Capacity
Boyle’s Law, whole core CT imaging, whole core
Source Sample Depth He Kr* CO2*
Barnett 26-Ha 8620.1 5.5+ 9.9 12.8
Eagle Ford EF-4 11184.8 6.3 11.0 17.5
Haynesville TWG3-2 11134.05 4.5 7.8 14.4
Permian P-2 10134.25 - 5.6 10.2
+ Aljamaan, 2013, * CT storage capacity for each gas at comparable equilibrium pressures of 179 to 250 psi for Kr and ~ 800 psi for CO2
Effective porosity (He) and storage capacity by gas type (Kr and
CO2) at comparable pressures
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Porosity and Storage Capacity
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𝜉avg= 6.38%
Pp=428.9 psi t= 24.16 hrs
𝜉𝜉avg= 6.60%
Pp=435 psi t= 1.11 hrs
Permian P-2
Eagle Ford EF-4
𝜉avg= 10.95%
Pp=240 psi t= 28 hrs𝜉avg= 6.68%
Pp=327.4 psi t= 3.15 hrs𝜉
(a) (b)
(c) (d)
Kr Adsorption vs Time
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𝜉avg= 7.10%
Pp=761 psi t= 120.34 hrs𝜉𝜉avg= 6.78%
Pp=637 psi t= 64.14 hrs
𝜉avg= 6.38%
Pp=428 psi t= 46.98 hrs
𝜉avg= 5.62%
Pp=179 psi t= 22.81 hrs
(a)
(b)
(c)
(d)
(a) (b) (c) (d)
Kr Adsorption vs Pore Pressure
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Pupstream=815.2, Pdownstream=779 psit ≈ 24 hours
Pupstream=762, Pdownstream=755 psit ≈ 48 hours
Pupstream=804, Pdownstream=690 psit ≈ 2.5 hour
Constant Upstream Injection
CO2 Adsorption vs Time
• FEI Magellan 400 XHR SEM
• 15kv, 13 nA, CBS-A, 200X, dwell 1 sec
• Bruker Quantax XFlash 6160 EDS
• Spectra maps and phase analysis
• Spot size 0.75 m
• MAPS 2.0.41.964
• Mosaic acquisition and construction
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MAPS 2.0.41.964
Scanning Electron Microscope (SEM)
and Energy Dispersive Spectroscopy
(EDS)
• Image collection
• Elemental data collection
• Qmap
• Phase analysis
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Fe Ca Carbonates and
carbonate-rich
matrix
Silicates and
silicate-rich
matrix
Pyrite
Organic matter
EFSEM and EDS Analysis
1 inch diameter
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Pixel Size: 1.45 µm
Eagle Ford
CO2KrSEM
Voxel dimensions: 190×190×1000 μm
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𝝃
Multiscale Image Registration
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Barnett 26-Ha Eagle Ford EF-4 Haynesville TWG3-2
Permian P-2, CT Permian P-2, µCT core top Permian P-2, µCT SEM mount
CT - 190×190×1000 μm
µCT - 27 x 27 x 27 µmDense CT and µCT Regions
Kr CO2
• CO2 and Kr storage distribution slices aligned with SEM mosaic
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Low 𝝃
High 𝝃𝝃
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Eagle FordCT/SEM Registration
CO2
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300 µm 30 µm
P
OM
P – Pyrite
OM – Organic Matter
Matrix – mixture of clay
and carbonate1 inch diameter
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Pixel Size: 1.45 µm
Pixel Size: 366 nm Pixel Size: 74 nm
𝝃Interpretation – Eagle Ford, High 𝝃
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Eagle Ford
Carbonates and
carbonate-rich matrix
Silicates and silicate-
rich matrix
Silicate- and
carbonate-rich matrix
(~50/50)
Pyrite
Organic matter
High
Open fractures
and less
secondary
mineralization
Low
Extensive
secondary
mineralization
Interpretation – High and low storage capacity regions
Kr CO2
• Inaccessible zones appear with both CO2 and Kr but is more evident in CO2
• Large isolated nodules correspond to low storage capacity zones
• Kr and CO2 mostly flows through the fractures
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𝝃𝝃
Interpretation - Haynesville TWG3-2
Core CT data
200 µm
CO2
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• Nodules (pyrite, barite, carbonate) low Kr and CO2 adsorption
200 µm
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Pixel Size: 366 nm Pixel Size: 366 nm
𝝃
Interpretation - Haynesville TWG3-2
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Haynesville
Carbonates and
carbonate-rich matrix
Silicates and silicate-
rich matrix
Barite
Pyrite
Organic matter
High
Open fractures
and less
secondary
mineralization
Low
Extensive
secondary
mineralization
Interpretation – High and low storage capacity regions
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Permian
Carbonates and
carbonate-rich matrix
Silicates and silicate-
rich matrix
Barite
Pyrite
Organic matter
High
Less secondary
mineralization
Low
Extensive
secondary
mineralization
Interpretation – High and low storage capacity regions
Kr CO2
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𝝃
Interpretation – Barnett 26-Ha
Barnett
Carbonates and
carbonate-rich matrix
Silicates and silicate-
rich matrix
Pyrite
Organic matter
High
Open fractures
and secondary
carbonate
mineralization
in clay matrix
Low
Clay-rich
regions,
secondary
carbonates as
fracture fill
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Interpretation – High and low storage capacity regions
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Sample
Maximum
Volume
@ STP
(cc/g)
Pore
Capacity
(cc/g)
Surface
Area
(m2/g)
Gas
Barite 5.4 0.009 0.980 N2
Pyrite 3.7 0.006 1.513 N2
CaCO3 3.5 0.005 1.239 N2
Illite* 63.6 0.079 15.500 Ar
Silurian Kerogen* 227.9 0.277 50.116 Ar
Eagle Ford EF-4 30.2 0.047 13.744 N2
Haynesville TWG3-2 21.6 0.034 5.901 N2
* Courtesy of R. Holmes
Low Pressure Adsorption
• Work flow of multiscale (cm to nm) imaging
Gas accessibility and storage capacity in intact shale cores
SEM mosaics of either core face or interior slices
Elemental mapping and interpretation
Image registration methods (same resolution and multiscale)
• Storage capacity of CO2 (10 to 17.5%) in all study cores is greater than Kr (5.6 to 11%). Both
are greater than the He porosity or amount of void space (4.5 to 6.3 %)
• Open fractures, secondary mineralization, matrix composition, and other features are interpreted
with respect to their impact on accessibility and gas storativity
• Gas storage and its distribution is controlled by
porosity
accessibility
sorption capacity of minerals and organic matter
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Conclusions
• Stanford Center for Carbon Storage (SCCS)
• SUPRI-A Industrial Affiliates
• BP and BHP Billiton
• H. Aljamaan acknowledges his graduate fellowship from Saudi Aramco
• Randall Holmes
• Stanford Nano Shared Facilities (SNSF)*
*Part of this work was performed at SNSF using a ZEISS Xradia 520 Versa, acquired with support from NSF under
award CMMI-1532224. SNSF is supported by the NSF as part of the National Nanotechnology Coordinated
Infrastructure under award ECCS-154215.
Slide 29Acknowledgements / Thank You / Questions