ryan herz-thyhsen and john kaszuba - wyoming … herz... · ryan herz-thyhsen and john kaszuba ......
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Ryan Herz-Thyhsen and John Kaszuba
View of Precision Drilling #18 while drilling Hornbuckle 1-11H in Converse County, Wyoming. (Paul Clark, geologist for Sunburst Consulting)
Outline • Motivation and Hypothesis
• Formation and Fluid Characterization
Laboratory
Experiments
Field
Production
Geochemical
Modeling
Motivation
How will hydraulic fracturing fluids
interact with the host rock?
- Dissolution/Precipitation reactions?
- Porosity/Permeability changes?
Reactions between minerals and hydraulic fracturing
fluid cause precipitation and dissolution of minerals,
potentially opening/closing pores and fractures.
Hypothesis
Niobrara Fm
Minerals Quartz Calcite
Illite
Plagioclase Pyrite Kaolinite
Up
per
Cre
tace
ou
s
Nio
bra
ra
Fro
nti
er
11797’
12076’ 12101’
12466’
Niobrara
Niobrara Chalk
Niobrara Target
Sage Breaks Member
Frontier Target
2nd Frontier
3rd Frontier
12239’
12562’
12717’
12970’
13158’
1st Frontier
Clays
Organic Material
Qtz
Calcite
Clays
Frontier Fm
Minerals Quartz Calcite
Illite
Plagioclase Pyrite
Kaolinite Glauconite
Up
per
Cre
tace
ou
s
Nio
bra
ra
Fro
nti
er
11797’
12076’ 12101’
12466’
Niobrara
Niobrara Chalk
Niobrara Target
Sage Breaks Member
Frontier Target
2nd Frontier
3rd Frontier
12239’
12562’
12717’
12970’
13158’
1st Frontier
Hydraulic Fracturing Fluid Chemical Field Purpose Mass Fraction
Cheyenne River Water Solvent 86.9%
Bauxite and Ultraprop Proppant 11%
Petroleum Distillates Optimize injection rates 0.38%
HCl Dissolves/breaks rock 0.12%
Tetramethylammonium Chloride Clay stabilizer 0.088%
Methanol Prevents corrosion and reduces friction 0.07%
Sodium Erythorbate Prevents metal precipitation 0.0009%
Experiments: • Niobrara Fm + Hydraulic Fracturing Fluid
• Frontier Fm + Hydraulic Fracturing Fluid
• React Rocks and Fluids for ~750 hours
Experimental Design
Seyfried, 1987
Conclusions • Experiments are necessary to understand small scale mineral-fluid reactions
in the rock. These reactions occur on lab time scales comparable to the field.
• Trace elements and heavy metals are initially released from the rock, but in a
closed system, are incorporated back into the rock (by mineralization?).
• Feldspar alters to clay. Existing clay minerals alter by ion exchange and/or
neocrystallization.
• Fracturing fluid saturates with Silica, while acid-attack on silicate minerals is
evident.
• The fluid approaches equilibrium with the rock in the first day, and the
biggest changes in mineral-fluid equilibria are witnessed within a few hours.
Laboratory
Experiments
Geochemical Model
HCO3-
5.33
Cl-
20.57
SO42-
15.17 Ca2+
6.02 K+
0.63
Mg+
6.82
Na+
18.78
Hydraulic Fracturing Fluid (mmol/L)
Quartz
64%
Calcite
20%
Illite
10%
Fron
tier Fo
rmatio
n
Quartz
15%
Calcite
45%
Illite
30%
Nio
brara Fo
rmatio
n
Plagioclase 5% Pyrite 5% / 1%
Conclusions • Experiments are necessary to understand small scale mineral-fluid reactions
in the rock. These reactions occur on lab time scales relevant to hydraulic
fracturing.
• Trace Elements are initially released from the rock, but in a closed system,
are incorporated into the rock by mineralization.
• Feldspar alters to clay. Existing clay minerals alter by ion exchange and/or
neocrystallization.
• Fracturing fluid saturates with Silica, while acid-attack on silicate minerals is
evident.
• The fluid approaches equilibrium with the rock in the first day, and the
biggest changes in mineral-fluid equilibria are witnessed within a few hours.
• Computer models predict reactions observed in experiments.
Geochemical Modeling
Laboratory Experiments
Conclusions • Experiments are necessary to understand small scale mineral-fluid reactions
in the rock. These reactions occur on lab time scales relevant to hydraulic
fracturing.
• Trace Elements are initially released from the rock, but in a closed system,
are incorporated into the rock by mineralization.
• Feldspar alters to clay. Existing clay minerals alter by ion exchange and/or
neocrystallization.
• Fracturing fluid saturates with Silica, while acid-attack on silicate minerals
is evident.
• The fluid approaches equilibrium with the rock in the first day, and the
biggest changes in mineral-fluid equilibria are witnessed within a few hours.
• Computer models predict reactions observed in experiments.
• Reactions occur more quickly in models.
• Produced fluid from wells shows the same geochemical trend as both models
and experiments.
Furthering our understanding of fluid-rock reactions in the lab and through
modeling will help us better understand fluid-rock interactions in the field
Future Work
• X-Ray Analyses
– X-Ray Diffraction
– X-Ray Fluorescence
• Organic Analyses
• Fluid-rock ratio sensitivity analyses
• Varying fluid composition in future experiments
and geochemical models
Acknowledgements
• Energy GA from the State of Wyoming via the Research Office
• Paul Lawless and the Helis Oil & Gas Co.
• Janet Dewey
• Norbert Swoboda-Colberg
• Kaszuba group: Virginia Marcon, Quin Miller, Alexa Socianu, Steve Levesque, and Mike Schedel
• Caroline Lo Ré and Jeff Martin
Measurement Niobrara Frontier Niobrara Frontier Niobrara Frontier units
Specific Gravity 1.0301 1.0365 - - - -
pH 6.22 6.28 6.29 6.57 6.9 7.26
Temperature 65.2 66.7 - - 115 115 F
Resistivity 0.19 0.16 - - - - Ohm.m
Iron 12 3 0.302 0.287 0 0 mg/L
Potassium 200 200 49 58 5.12 2.2 mg/L
Calcium 1413 1692 264 243 7.7 0.5 mg/L
Magnesium 153 187 62 65 0 0 mg/L
Chloride 23720 28480 737 715 1.45 1.45 mg/L
Sulfate 0 0 1496 1371 1363 1352 mg/L
Bicarbonate 293 329 - - 382 78 mg/L
Sodium 13441 16165 571 550 823 691 mg/L
Silica - - 44 62 103 77
Produced Water
Conclusions
• Mineralogy changes in the formation by clay ion
exchange or neocrystallization
• Rock is in control of the fluid-rock system; the fracturing
fluid approaches equilibrium with the rock within the first
day
• Inorganic reactions occur primarily within the first day,
often in the first few hours
• Silica increases in both experiments and models
Niobrara Formation
• Initial immediate pH increase
• Also visible in experiments
pH decline also visible
in experiments
EHR-001
0.1
1
10
100
1000
10000
0 0.2 0.4 0.6 0.8 1
um
ol/
kg
Sample Number
EHR-001 Fluid Chemistry
Li
Mo
Rb
Sr
V
W
0.1
1
10
100
1000
0 0.2 0.4 0.6 0.8 1
um
ol/
kg
Sample Number
EHR-001 Fluid Chemistry
Fe
Al
Ba
Co
Cu
Mn
Pt
Sb
Frontier Formation
• Initial immediate pH increase
• Also visible in experiments
pH decline also visible
in experiments
Fluid Fluid Volume
(gal) Constituents
HCl 15 13,000 A264, L058, W054, F110
WF125 23,500 B306, F110, W054, L064, J481
WF135 139,000
YF125LGD 176,000 B306, L010, M007, J511, F110, W054, L064, J569, J218, M298L, SS85-2040 YF135LGD 1,058,000
WF110 134,589 B306, F110, W054, L064, J218
• F110 – methanol, ethoxylated alcohols • L064 – tetramethylammonium chloride • J218 – diammonium peroxidisulphate
Niobrara B chalk – there because it’s more brittle. Fractures extend up 150 ft and down 70 ft
(200-210 ft of vertical section). Laterally about 500 feet (so out of the board). Not a lot of natural fractures and pore throats are very small. 9000’ laterals (usually ~4500’)
Frontier upper 2nd bench (12560’)– there because it’s coarse grained. Extend as high as top of core, below bottom of core
• F110 – methanol, ethoxylated alcohols • L064 – tetramethylammonium chloride • J218 – diammonium peroxidisulphate