Methane (CH4) wettability of clay coated quartz at reservoir conditions

3 days ago - Support. Get Help · For Advertisers · Institutional Sales; Live Chat. Partners. Atypon · CHORUS · COPE · COUNTER · CrossRef · CrossCheck ...
0 downloads 0 Views 580KB Size
Subscriber access provided by UNIV OF LOUISIANA

Fossil Fuels

Methane (CH4) wettability of clay coated quartz at reservoir conditions Bin Pan, Franca Jones, Zhaoqin Huang, Yongfei Yang, Yajun Li, Seyed Hossein Hejazi, and Stefan Iglauer Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.8b03536 • Publication Date (Web): 17 Jan 2019 Downloaded from http://pubs.acs.org on January 20, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Methane (CH4) wettability of clay coated quartz at reservoir conditions

1 2

Bin Pana, Franca Jonesb, Zhaoqin Huangc, Yongfei Yangc, Yajun Lid, Seyed Hossein Hejazia,

3

Stefan Iglauere

4

aDepartment

5

T2N 1N4, [email protected]; [email protected]

6

bDepartment

7

Australia, PO Box U1987, [email protected]

8

cSchool

9

Changjiang West Road, Qingdao, China, 266580, [email protected];

of Chemical and Petroleum Engineering, University of Calgary, Calgary, Canada,

of Chemistry, Nanochemistry Research Institute, Curtin University, Perth WA 6845,

of Petroleum Engineering, China University of Petroleum (East China), No. 66,

10

[email protected]

11

dKey

12

(East China)), Ministry of Education, Qingdao, 266580, P.R. China, [email protected]

13

eSchool

14

[email protected]

Laboratory of Unconventional Oil & Gas Development (China University of Petroleum

of Engineering, Edith Cowan University, 270 Joondalup Drive, Joondalup, Australia,

15 16

*corresponding

17

[email protected])

authors ([email protected]; [email protected]; [email protected];

18 19

Abstract

1 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 31

20

Methane (CH4) wettability of shale is a key parameter which determines pore and reservoir-scale

21

fluid distributions, CH4 reserves estimation, and ultimate recovery efficiency from shale gas

22

reservoirs. Clay minerals usually fill the pore spaces or are adsorbed on the surface of shale rock,

23

thus influencing CH4 wettability. However, a systematic investigation of the influence of clay on

24

CH4 shale-wettability is lacking. Herein, we investigated the role of clay, pressure, temperature,

25

and salinity on CH4 wettability of clay coated quartz (i.e. a well-defined model system for

26

shales). Results indicated that the advancing and receding water contact angles for clean,

27

kaolinite coated and montmorillonite coated quartz increased with pressure. However, the effect

28

of temperature on wettability is complex, thus the advancing water contact angle for clean quartz

29

increased with temperature while an opposite trend was found for clay coated quartz. At low

30

temperature (i.e. 300 K), clay coating de-wetted the quartz surface, while at elevated temperature

31

(i.e. 323 K), clay coating increased the hydrophilicity of the quartz surface. Furthermore,

32

kaolinite clay particles demonstrated a stronger influence on quartz wettability than

33

montmorillonite particles, both, at high and low temperatures. In addition, higher NaCl salinity

34

led to higher advancing water contact angles for the aforementioned three solid surfaces. The

35

effect of salinity on CH4 wettability is thus intensified in the presence of clays. These insights

36

will thus improve the accuracy of CH4 reserve estimates and aid methane recovery schemes.

37 38

Key Words: Wettability; advancing and receding contact angles; elevated pressures and

39

temperatures; kaolinite; montmorillonite; shale gas recovery; shale gas reserves estimation.

40 41

1.

Introduction

2 ACS Paragon Plus Environment

Page 3 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

42

Shale reserves play an important role in meeting the global demands for energy. The significant

43

development in gas production from such shale gas reservoirs is due to advances in horizontal

44

drilling and hydraulic fracturing technology 1-6. Although in commercial production, there are

45

challenges in evaluating the characteristics of these hydrocarbon reservoirs due to the complexity

46

of gas storage and transport processes in the micro- and nano-scale pore geometries 7,8. In this

47

context, wettability, characterized by the brine contact angles of CH4-brine-shale rock (𝜃) is a

48

key parameter that determines CH4 reserves and production efficiency 9-13. In particular, CH4

49

reserves, CH4 distribution, and free gas flow in the shale pores are strongly affected by the

50

capillary pressure (𝑃𝐶) which is a function of contact angle12,14-22. For example, for a circular

51

capillary tube, based on the Young-Laplace Equation:

52

𝑃𝑐 =

2𝛾𝑐𝑜𝑠𝜃 𝑟

Equation 1

53

Where 𝛾 is the interfacial tension between CH4 and brine and 𝑟 is the average pore radius. When

54

𝜃 < 90°, the shale rock has a stronger affinity to brine than CH4 and 𝑃𝑐 could be a driving force

55

for CH4 recovery as water would imbibe more easily; while if 𝜃 > 90°, the shale rock is more

56

CH4-wet than water-wet and 𝑃𝑐 would tend to resist water imbibition.

57

Organic rich shales are mainly composed of consolidated clay sized particles with a high organic

58

content, a complex chemical composition filled or covered with clay 23-25, which complicates

59

contact angle analysis. For example, clay crystal size is much smaller than the usual sessile

60

droplet, which prevents standard wettability measurements 26-28. Previous literatures reported that

61

kaolinite and montmorillonite crystal sizes are smaller than 2 𝜇𝑚 29,30, while the usual sessile

62

droplet size is around 2000 𝜇𝑚 31,32. To avoid the challenge to measure the contact angle of clay

63

using the sessile method, Borysenko et al. 2009 used liquid-liquid extraction method to validate 3 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 31

64

montmorillonite as a hydrophilic surface and kaolinite as a hydrophobic surface 28. However,

65

liquid-liquid extraction method could not report the specific contact angle value 33. Schmatz et al.

66

2015 reported a more water-wet nature of kaolinite based on cryo SEM results 34. However, cryo

67

SEM method is destructive 35. Ballah et al. 2016 measured the wettability of clay coating on

68

glass slide using sessile method and all the contact angles measured in their work were smaller

69

than 40º (i.e. a strong water-wet surface) 36. However, all their measurements were conducted at

70

ambient conditions, which could not represent the real wettability of clay at reservoir conditions

71

as pressure and temperature could also influence wettability significantly 37,38. A recent study

72

compacted clay powders into solid substrates and measured the brine contact angles of the

73

CO2/N2/oil-brine-clay systems at reservoir conditions 39. They concluded that montmorillonite is

74

oil-wet, while kaolinite and illite are water-wet at typical reservoir conditions 39. However, they

75

did not measure clay wettability in the system of CH4-brine-clay system, which is related to shale

76

gas production 9-13. Molecular dynamic simulations, which overcome these limitations, predicted

77

that Na-/Ca- montmorillonite becomes more hydrophobic when exposed to CO2 at reservoir

78

conditions 40. Šolc et al. 2011 calculated the contact angle of water-air-kaolinite was 105º using

79

molecular dynamic simulation 41. Thus, the inconsistency between experimental and simulated

80

results is clear and clay wettability is still open to large uncertainty. However, how clay

81

influences the wettability of organic rich shales at reservoir conditions has not been explored.

82 83

In the present study, we thus investigate the CH4 wettability of clay coated quartz at reservoir

84

conditions. Note that we use the words clay and clay minerals interchangeably in this work. To

85

isolate the role of shale constituents, we use quartz, one of the most primary components of shale

86

42-47,

coated with clay particles, instead of real rock samples. Thus, we can elucidate the role of 4 ACS Paragon Plus Environment

Page 5 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

87

clay types on the wettability without perturbations from other chemical components in shale.

88

Furthermore, the effects of pressure, temperature and salinity on CH4 wettability are also

89

presented.

90 91

2.

Experimental Methodology

92

To remove any residual contaminants from the quartz surface 48,49, all alpha - quartz substrates

93

(Supplied by Dade Quartz Co., Ltd, China, with RMS surface roughness of less than 1 nm

94

measured with an JPK NanoWizard 4 Atomic Force Microscope (AFM), SI-Figure 1a) were

95

carefully cleaned following a standard procedure. First, the substrates were washed by acetone

96

and subsequently soaked in piranha solution (3 parts of 98 wt% H2SO4 and 1 part of aqueous 30

97

wt% H2O2 for 30 mins at 300 K; H2SO4 and H2O2 were purchased from Sinopharm Chemical

98

Reagent Co., Ltd.). Afterwards, the immersed substrates were covered with aluminum foil and

99

dried in a clean oven for 8 hours at 353 K. A concentration of 2 wt% kaolinite or

100

montmorillonite suspension was prepared respectively through adding kaolinite or

101

montmorillonite powders into 1.5 wt% NaCl brine (kaolinite, montmorillonite, and sodium

102

chloride were obtained from Sigma-Aldrich; NaCl purity was  99 mol%). Note that the

103

chemical formula of kaolinite is Al2O7Si2 · 2H2O and the montmorillonite is K 10 catalyst,

104

MgNaAl5(Si4O10)3(OH)6. A relatively high NaCl salinity was used here to impede clay

105

accumulation/swelling and promote clay adsorption onto quartz surface 50,51. The total salinities

106

of clay suspensions in DI water and in 1.5 wt% NaCl brine were measured using Starter3100M

107

at room temperature, See SI-Table 1 in supporting information. It was found that the total

108

salinity of clay suspensions is extremely low, showing no apparent difference with the salinity of

109

pure DI water. A concern may be that such high Na+ concentration would exchange with in-situ 5 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 31

110

divalent cations from clay minerals. However, as we shown in SI-Table 1 and 2, the ions salinity

111

from in-situ clay were extremely low and the wettabilities for Na+ and Mg2+ were very similar.

112

Thus, it was assumed that the ions exchange would not influence wettability in this work. The

113

particle size distributions (PSD) of the kaolinite and montmorillonite were measured thrice via a

114

Zetasizer Nano instrument (Malvern, UK). The average particle sizes for kaolinite and

115

montmorillonite were 1050 nm and 900 nm respectively. The total organic content (TOC) for

116

kaolinite and montmorillonite were 335 mg/kg and 3093 mg/kg, respectively, measured by an

117

Elab-TOC instrument.

118 119

The kaolinite and montmorillonite suspensions were stirred for 2 hours at 323 K. Afterwards, the

120

clean quartz substrates were aged in the 2 wt% kaolinite or montmorillonite suspensions for 6 hrs

121

and then the aged substrates were covered with clean aluminium foil and dried for 6 hrs. The

122

total 12 hrs duration would assure a stable coating 50. The morphological properties of clean and

123

coated substrates were characterized using AFM (Note that RMS roughness of clean and

124

kaolinite coated quartz were measured by JPK NanoWizard 4 Atomic Force Microscope, while

125

RMS of montmorillonite quartz was measured via Bruker Multi mode 8 Atomic Force

126

Microscope, please see SI-Figure 1 in the supporting information) and SEM measurements (by

127

Philips XL 30 SEM), Figures 1. The RMS roughness values for clean, kaolinite coated and

128

montmorillonite coated quartz were 483.7 pm, 629.8 nm and 863 nm, respectively. However, at

129

this scale, the effect of roughness on contact angle is insignificant 52. Based on the analysis of

130

SEM images using MATLAB, the average kaolinite and montmorillonite coverages were

131

37.48% and 39.02%, respectively, please see SI-Figure 2 in the supporting information.

132

Furthermore, the SEM images demonstrated a more compact coating on the montmorillonite 6 ACS Paragon Plus Environment

Page 7 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

133

coated surface. The advancing (𝜃𝑎) and receding (𝜃𝑟) brine contact angles of CH4-brine-

134

clean/clay coated quartz systems were then measured by a Krüss DSA 100 instrument using the

135

tilted plate method 53 as described previously in detail 23. All the contact angle measurements

136

were finished within the initial 30 s. We did not observe the contact angle for a long time in this

137

work, because the droplet could destabilise and displace the clay coating after long time contact.

138

However, a future work would investigate long-term clay wettability using a recent developed

139

LbL coating method 54. Furthermore, we did not consider the influence from CH4-brine

140

dissolution because of a very low dissolution capacity between brine and CH4 55. Note that in

141

shale gas extraction, 𝜃𝑎 corresponds to CH4 recovery, while 𝜃𝑟 is related to initial CH4/water

142

distribution 56.

143

144 145

(a)

146

7 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 31

147 148

(b)

149 150

(c)

151 152

(d)

8 ACS Paragon Plus Environment

Page 9 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

153

(e)

154 155

Figure 1. SEM images of clean (a), kaolinite coated (b,c) and montmorillonite coated (d,e)

156

quartz used in the experiments. The light color is clay particle and the dark color is quartz

157

substrate.

158 159

3.

Results and Discussion

160

3.1

161

The effects of pressure and temperature on the brine contact angles were measured for the

162

various substrates at multiple pressures (0.1 MPa to 20 MPa) and temperatures (300 K and 323

163

K), Figure 2.

Effect of pressure and temperature on contact angles

9 ACS Paragon Plus Environment

Energy & Fuels

50

Clean, 300 K

Advancing contact angle [º]

45

Clean, 323 K

40

Kaolinite coated, 300 K

35

Kaolinite coated, 323 K Montmorillonite coated, 300 K

30

Montmorillonite coated, 323 K

25 20 15 10 5 0 0

5

10 P [MPa]

164

15

20

(a)

165

50 Receding contact angle [º]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 31

45

Clean, 300 K

40

Clean, 323 K

35

Kaolinite coated, 300 K Kaolinite coated, 323 K

30

Montmorillonite coated, 300 K

25

Montmorillonite coated, 323 K

20 15 10 5 0 0

166

5

10 P [MPa]

15

20

10 ACS Paragon Plus Environment

Page 11 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

167

(b)

168

Figure 2. Effect of pressure and temperature on the (a) advancing and (b) receding brine contact

169

angles of clean/kaolinite coated/montmorillonite coated quartz-CH4-brine systems. (Note that the

170

aqueous phase is 1.5 wt% NaCl brine).

171 172

Both, 𝜃𝑎 and 𝜃𝑟 for all substrates clearly increased with pressure, consistent with literature data

173

measured for several different gases on various substrates 23,38, 43,52,57,58,59. For example, at 300

174

K, when pressure increased from 0.1 MPa to 20 MPa, 𝜃𝑎 for clean, kaolinite and montmorillonite

175

coated quartz increased by 30º, 29º and 21º, respectively, while 𝜃𝑟 for the above three surfaces

176

increased by 22º, 25º and 15º, respectively.

177

Noteworthy was the effect of temperature on the wettability. 𝜃𝑎 for clean quartz increased with

178

temperature, consistent with literature data reported for quartz 52, hydrophilic dolomite 31 and

179

shale 37, while 𝜃𝑎 for clay coated quartz decreased with temperature, consistent with literature

180

data reported for mica 58,59, hydrophobic dolomite 31 and 3 wt% TOC shale 23. Specifically, at 15

181

MPa, when temperature increased from 300 K to 323 K, 𝜃𝑎 changes for clean, kaolinite coated

182

and montmorillonite coated quartz were 9º, -13º and -8º respectively; at 20 MPa, for the same

183

temperature increase, 𝜃𝑎 changes for above three surfaces were 5º, -24º and -6º, respectively.

184

Physically, the influence of pressure on wettability can be attributed to the higher non-aqueous

185

phase density 38,57, the consequently stronger intermolecular interactions between CH4 and the

186

solid surface due to the increased molecular density 23,57,60-63, and the corresponding decrease in

187

the interfacial tension between the solid surface and CH4 64. The underlying mechanism of the

11 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 31

188

temperature influence on wettability can be explained by the sharp-kink approximation 31,37,

189

equation 2 below.

190

𝑐𝑜𝑠𝜃 = ―1 +

∆𝝆𝑰 𝜸𝒍𝒈

Equation 2

191

Where ∆𝜌 is the approximate density difference between the adsorbed brine film and CH4; 𝛾𝑙𝑔 is

192

the interfacial tension between brine and CH4; and I is the van der Waals potential integral.

193

Clearly, both 𝛾𝑙𝑔 and ∆𝜌 increased with temperature 58,65. However, the relative increase in ∆𝜌

194

with temperature was more significant than that of 𝛾𝑙𝑔 31,37, which reduces the contact angle; the

195

van der Waals potential decreases with temperature 66, which increases the contact angle. Thus,

196

in both scenarios, a  increase or decrease with temperature is possible. For clean quartz, the

197

temperature-driven influence on van der Waals interaction was more effective, resulting in a

198

contact angle increase with temperature 31. For clay coated quartz, this van der Waals interaction

199

might be relatively weak, thus the contact angle decreased with temperature.

200 201

3.2

Effect of brine salinity on contact angles

202

All 𝜃𝑎 increased with salinity as depicted in Figure 3. Specifically, when NaCl salinity increased

203

from 1.5 wt% to 15 wt%, 𝜃𝑎 for clean, kaolinite coated and montmorillonite coated quartz

204

increased by 6º, 15º and 10º, respectively.

205

12 ACS Paragon Plus Environment

Page 13 of 31

50 45

Clean

40 Contact angle [°]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Kaolinite coated

35 Montmorillonite coated

30 25 20 15 10 5 0 2

4

8 10 Salinity [wt%]

206

14

207

Figure 3. The advancing brine contact angles of CH4-clean/kaolinite coated/ montmorillonite

208

coated quartz-brine systems at 10 MPa and 323 K.

209 210

This result is consistent with literature data for NaCl - oil - sandstone 67, NaCl - glass/kaolinite

211

coated glass - crude oil 68, NaCl - oil - kaolinite coated glass 69, NaCl - CO2 - mica 58,59,70; and

212

NaCl-CO2-quartz 38,62 systems. The effect of salinity on the advancing water contact angles can

213

be explained with the Derjaguin Landau Verwey Overbeek (DLVO) theory as discussed in our

214

previous work23. In order to shed more light on the underlying mechanism of salinity influence

215

on the contact angles, we also measured the corresponding zeta potentials (using a Zetasizer

216

Nano instrument, Malvern, UK) and pH values (using a RHA-SHKY pH Meter Model 8601

217

instrument), Table 1. Every zeta potential measurement was repeated 18 times, and every pH

218

measurement was repeated 3 times. 13 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 31

219 220

Table 1. Zeta potential and pH data for various systems at two different temperatures in this

221

work.

300 323 300 323 300

Mean zeta potential [mV] -0.86 1.21 1.91 3.49 -14.7

300

-21.9

0.574

323

-12.6

0.872

323

-19.6

0.967

300 300 323 323 323 323

-7.51 -10.1 -3.04 -2.14 2.37 3.48

7.88 6.3 6.58 3.59 9.31 8.97

Temperature [K]

Samples 1.5 wt% NaCl 1.5 wt% NaCl 5 wt% NaCl 5 wt% NaCl 2 wt% Kaolinite + 1.5 wt% NaCl 2 wt% Montmorillonite + 1.5 wt% NaCl 2 wt% Kaolinite + 1.5 wt% NaCl 2 wt% Montmorillonite + 1.5 wt% NaCl 2 wt% Kaolinite + 5 wt% NaCl 2 wt% Montmorillonite + 5 wt% NaCl 2 wt% Kaolinite +5 wt% NaCl 2 wt% Montmorillonite +5 wt% NaCl 2 wt% Kaolinite +10 wt% NaCl 2 wt% Montmorillonite +10 wt% NaCl

Standard Mean Standard deviation pH deviation [mV] 1.01 6.45 0.786 4.94 6.25 0.03 6.65 0.436 6.25 0.58 4.74

0.23

5.61 3.48

0.02 0.01

222 223

Higher temperatures led to less negative zeta potentials; while the addition of kaolinite or

224

montmorillonite reduced the zeta potential. Furthermore, clay suspensions are not stable and

225

uniform solutions and this intrinsic property could cause a significant variation in the measured

226

properties 71.

227

In addition, montmorillonite suspensions were more acidic than the corresponding kaolinite

228

suspensions; while a higher NaCl salinity led to a lower pH value for both, montmorillonite and

229

kaolinite, suspensions. Higher pH values lead to more negative zeta potentials 72, and thus lower

230

contact angles. However, it would not be explained why the contact angle for 2 wt% 14 ACS Paragon Plus Environment

Page 15 of 31

231

montmorillonite + 1.5 (or 5 wt%) wt% NaCl brine sample was smaller than that for 2 wt%

232

kaolinite + 1.5 (or 5 wt%) wt% NaCl brine sample at 300 K just based on pH. We hypothesize

233

that the surface microstructural evolution and (clay) hydration of the coated surface also played

234

an important role, causing the different wettability behavior for kaolinite and montmorillonite

235

coated surfaces, besides the solution property 60,73. Clearly, the contact angle strongly correlated

236

with the zeta potential, Table 2 and Figure 4.

237

Table 2. The used data for plotting Figure 4.

238

Solution Systems 2 wt% Montmorillonite + 1.5 wt% NaCl 2 wt% Kaolinite + 1.5 wt% NaCl 2 wt% Kaolinite +5 wt% NaCl 2 wt% Montmorillonite +5 wt% NaCl 2 wt% Kaolinite +10 wt% NaCl 2 wt% Montmorillonite +10 wt% NaCl

Zeta potnetial [mV]

Advancing contact angle [º]

-19.6

15

-12.6 -3.04 -2.14 2.37 3.48

15 22 23 24 26

239

Advancing contact angle [º]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

30 25 20 15 10 5 0 -20

-15

-10 -5 Zeta potential [mV]

0

5

240 15 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 31

241

Figure 4. The relationship between advancing contact angle and the corresponding zeta potential

242

at 10 MPa, 323 K and various NaCl salinities.

243 244

At 323 K, higher salinity led to larger zeta potential, thus higher contact angles. The zeta

245

potential for kaolinite was smaller than that for montmorillonite at the same NaCl salinity (5

246

wt% and 10 wt%, respectively), thus the contact angle for kaolinite was smaller than

247

montmorillonite. However, note that the zeta potential was measured at ambient conditions,

248

while the contact angle was measured at high pressure, although a correlation has been proposed

249

previously 71.

250 251

In summary, the increasing salinity increases the ionic strength, which better screens the surface

252

charge 61. Thus, the surface potential approaches zero and in some circumstances, positive

253

values. As a result, surface polarity and water affinity decreases, hence, an increasing water

254

contact angle results.

255 256

3.3

Effect of clay on quartz wettability

257

Based on the results and discussion in sections 3.1 and 3.2, it is easy to conclude that the effect

258

of clay on quartz wettability is extremely complex. For example, the effect of clay coating on

259

quartz wettability was different at low and high temperatures, Figure 2. At low temperature (i.e.

260

300 K), kaolinite or montmorillonite coating de-wetted the quartz, which could be attributed to

261

the lowered pH and intensified acidic properties, thus less negative zeta potential 72, and a larger

16 ACS Paragon Plus Environment

Page 17 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

262

contact angle 74; while at high temperature (i.e. 323 K), these coatings intensified quartz

263

hydrophilicity.

264

Furthermore, kaolinite always had a stronger influence on quartz wettability than

265

montmorillonite. For example, at 20 MPa and 300 K, 𝜃𝑎 for clean, kaolinite and montmorillonite

266

coated quartz were 30º, 47º and 34º, respectively, while at 20 MPa and 323 K, 𝜃𝑎 for above three

267

surfaces were 35º, 23º and 28º. The low temperature results (300 K) are consistent with literature

268

reports that a) kaolinite and montmorillonite clays were more oil-wet than quartz at 298 K and

269

0.1 MPa 28, that b) quartz had a stronger water adsorption capacity than kaolinite at 298 K 75 and

270

that c) brine contact angles of oil-water-sandstone systems increased with clay content on the

271

sandstone surface at ambient condition (i.e. 0.1 MPa and 287 K) 67. Furthermore, the results for

272

the clay influence at 323 K are consistent with literature reports where kaolinite reduced water

273

repellency of silica sand at 323 K more efficiently than montmorillonite 76. Although a recent

274

study reported clay wettability for CO2/N2/oil-brine-clay systems at reservoir conditions39, we

275

did not find any literature related to clay influence on shale wettability at high temperature and

276

high pressure, noting that reservoir conditions (i.e. elevated pressure and temperature) are critical

277

for gas behaviour at the pore-scale 77, which is again vital for the evaluation of CH4 reserves and

278

recovery.

279 280

In addition, the effect of salinity on CH4 wettability was intensified in the presence of clays at 10

281

MPa and 323 K, Figure 3. Specifically, when the NaCl salinity increased from 1.5 wt% to 15

282

wt%, for clean quartz, 𝜃𝑎 increased by 6° from 25° to 31°; compared with this, salinity had a

283

stronger influence on 𝜃𝑎 for the kaolinite coated (e.g. 𝜃𝑎 increased by 10° from 15° to 25°) and

17 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 31

284

montmorillonite coated surfaces (e.g. 𝜃𝑎 increased by 15° from 15° to 30°). Mechanistically, clay

285

particles have negatively charged surfaces at typical reservoir conditions 78, consistent with our

286

zeta potential results; the isoelectric points for quartz, kaolinite and montmorillonite are pH=3 52,

287

6 and 6.7 78. Montmorillonite has a greater number of structurally charged sites than kaolinite 79,

288

which results in a stronger attraction to positive charges (e.g. Na+). Thus, the surface potential

289

for Montmorillonite coated quartz approaches zero more quickly. Consequently, 𝜃𝑎 for

290

montmorillonite coated quartz increased more significantly than 𝜃𝑎 for both, kaolinite coated

291

quartz and clean quartz.

292 293

4.

Conclusions

294

CH4-shale wettability is a key parameter for predicting CH4 reserves and distribution9-13.

295

However, due to the complexity of the shale structure and composition, CH4-shale wettability

296

evaluation is still open to uncertainties. Specifically, clay minerals, as one of the abundant

297

constituents of shale formations, significantly increase the complexity of CH4-shale wettability.

298

Furthermore, a systematic investigation of clay effects on CH4-shale wettability in a

299

representative system is still scarce. To elucidate how clay influences shale wettability, we used

300

a well-defined model (i.e. clay coated quartz) to investigate the role of clay, pressure,

301

temperature and salinity on the CH4 wettability. The following conclusions were reached:

302

1. The quartz substrates became more water-wet at high temperature (i.e. 323 K) when coated

303

by clays, while they became more CH4-wet at low temperatures (i.e. 300 K). Kaolinite had

304

a stronger influence on quartz wettability than montmorillonite with respect to temperature

305

variations. We did not find any previous reports to compare the influence of clay coating 18 ACS Paragon Plus Environment

Page 19 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

306

or adsorption on shale and quartz wettability at different temperatures, especially at

307

reservoir pressures.

308 309 310 311 312 313

2. Elevated pressures increased the hydrophobicity of all three tested surfaces (i.e. clean, kaolinite coated and montmorillonite coated quartz). 3. Elevated temperatures de-wetted the clean quartz, while, it increased the hydrophilicity of clay coated quartz. 4. High NaCl salinity reduced surface hydrophilicity. This salinity effect was intensified in the presence of clays.

314 315

Acknowledgements

316

The authors wish to acknowledge financial assistance from the National Science and Technology

317

Major Project (2016ZX05023-001; 2016ZX05060-010; 2017ZX05009001), the Natural Science

318

Foundation of China (41602143; 51774310; 51509260; 51674280; 51711530131), Key Research

319

and Development Plan of Shandong Province (2018GSF116009), Applied Basic Research Projects

320

of Qingdao Innovation Plan (16-5-1-38-jch), the Fundamental Research Funds for the Central

321

Universities (18CX02104A; 18CX05029A; 17CX05003), the Chinese Scholarship Council, the

322

University of Calgary Global Research Initiative in Unconventional Hydrocarbon Resources-

323

Beijing Site, Kerui-MITACS Accelerate Research Fund Application Ref. IT09328, and Natural

324

Sciences and Engineering Research Council of Canada (NSERC).

325 326

References

327

1. Gregory, K.B., Vidic, R.D., and Dzombak, D.A. Water management challenges associated

328

with the production of shale gas by hydraulic fracturing. Elements 2011, 7 (3), 181 - 186, 19 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

doi: 10.2113/gselements.7.3.181.

329 330

Page 20 of 31

2. Jarvie, D.M., Hill, R.J., Ruble, T.E., and Pollastro, R.M. Unconventional shale-gas systems:

331

The Mississippian Barnett Shale of north-central Texas as one model for thermogenic

332

shale-gas assessment. AAPG Bull. 2007, 91 (4), 475 - 499, doi: 10.1306/12190606068.

333

3. Wang, J.J., Wang, B.E., Li, Y.J., Yang, Z.H., Gong, H.J., Dong, M.Z. Measurement of

334

dynamic adsorption–diffusion process of methane in shale. Fuel 2016, 172, 37 - 48,

335

10.1016/j.fuel.2015.12.069.

336

4. Aljamaan, H., Lsmail, M.A., Kovscek, A.R. Experimental investigation and Grand

337

Canonical Monte Carlo simulation of gas shale adsorption from the macro to the nano.

338

Journal of Natural Gas Science and Engineering 2017, 48, 119 - 137, doi:

339

10.1016/j.jngse.2016.12.024.

340

5. Dehghanpour, H., Lan, Q., Saeed, Y., Fei, H., and Qi, Z. Spontaneous imbibition of brine

341

and oil in gas shales: Effect of water adsorption and resulting microfractures. Energy Fuels

342

2013, 27 (6), 3039 - 3049, doi: 10.1021/ef4002814.

343

6.

Jiménez-Martínez, J., Porter, M.L., Hyman, J.D., Carey, J.W., and Viswanathan, H.S.

344

Mixing in a three-phase system: Enhanced production of oil-wet reservoirs by CO2

345

injection. Geophys. Res. Lett. 2016, 43, 196 - 205, doi: 10.1002/2015GL066787.

346

7. Curtis, M.E., Sondergeld, C.H., Ambrose, and R.J., Rai, C.S. Microstructural investigation

347

of gas shales in two and three dimensions using nanometer-scale resolution imaging. AAPG

348

Bull. 2012, 96 (4), 665-677, doi: 10.1306/08151110188.

349

8. Ambrose, R.J., Hartman, R.C., Diaz-Campos, M., Akkutlu, I.Y., and Sondergeld, C.H.

350

Shale gas-in-place calculations part I: New pore-scale considerations. SPE Journal 2012,

351

doi: 10.2118/131772-PA.

20 ACS Paragon Plus Environment

Page 21 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

352

9. Amann-Hildenbrand, A., Ghanizadeh, A., and Kross, B.M. Transport properties of

353

unconventional gas systems. Mar. Pet. Geol. 2012, 31 (1), 90 - 99, doi:

354

10.1016/j.marpetgeo.2011.11.009.

355

10. Takahashi, S., and Kovscek, A.R. Wettability estimation of low-permeability, siliceous

356

shale using surface force. Journal of Petroleum Science and Engineering 2010, 75 (1 - 2),

357

33 - 43, 10.1016/j.petrol.2010.10.008.

358

11. Chalmers, G.R.L., Ross,D.J.K., and Bustin, R.M. Geological controls on matrix

359

permeability of Devonian Gas Shales in the Horn River and Liard basins, northeastern

360

British Columbia, Canada. Int. J. Coal Geol. 2012, 103, 120 - 131, doi:

361

10.1016/j.coal.2012.05.006.

362 363 364 365

12. Bai, B.J., Elgmati, M., Zhang, H., and Wei, M.Z. Rock characterization of Fayetteville shale gas plays. Fuel 2013, 105, 645 - 652, doi:10.1016/j.fuel.2012.09.043. 13. Sahimi, M. (2011) Flow and transport in porous media and fractured rock: From conventional methods to modern approaches, Wiley-Vch, Weinheim, Germany.

366

14. Hu, Y.N., Devegowda, D., Striolo, A., Phan, A., Ho, T.A., Ho, T.A., and Sigal, R.F.

367

Microscopic dynamics of water and hydrocarbon in shale-kerogen pores of potentially

368

mixed wettability. SPE Journal 2014, doi:10.2118/167234-PA.

369

15. Shi, H., Luo, X.R., Li, X., Liu, N.G., Qi, Y.K., Fang, T., Zhang, L.K., and Lei, Y.H. Effects

370

of mix-wet porous mediums on gas flowing and one mechanism for gas migration. Journal

371

of

372

10.1016/j.petrol.2017.02.009.

373 374

Petroleum

Science

and

Engineering

2017,

152,

60

-

66,

doi:

16. Nelson, P.H. Pore-throat sizes in sandstones, siltstones, and shales: Reply. AAPG Bull. 2011, 95 (8), 1448 - 1453, doi: 10.1306/12141010159.

21 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 31

375

17. Liang, L.X., Luo, D.X., Liu, X.J., and Xiong, J, Experimental study on the wettability and

376

adsorption characteristics of Longmaxi Formation shale in the Sichuan Basin, China.

377

Journal of Natural Gas Science and Engineering 2016, 33, 1107 - 1118, doi:

378

10.1016/j.jngse.2016.05.024.

379

18. Zhou, Y.F., Helland, J., Hatzignatiou, D.G.A dimensionless capillary pressure function for

380

imbibition derived from pore-scale modelling in mixed-wet-rock images. SPE Journal

381

2012, https://doi.org/10.2118/154129-PA.

382

19. Zhou, Y.F., Helland, J., Hatzignatiou, D.G. Dynamic capillary pressure curves from pore-

383

scale

modelling

in

mixed-wet-rock

384

https://doi.org/10.2118/154474-PA.

images.

SPE

Journal

2013,

385

20. Zhou, Y.F., Helland, J., Hatzignatiou, D.G. Pore-scale modelling of waterflooding in

386

mixed-wet-rock images: Effects of initial saturation and wettability. SPE Journal 2014,

387

https://doi.org/10.2118/154284-PA.

388

21. Nielsen, L.C., Bourg, I.C., and Sposito, G. Predicting CO2–water interfacial tension under

389

pressure and temperature conditions of geologic CO2 storage. Geochim. Cosmochim. Acta

390

2012, 81, 28-38, doi: 10.1016/j.gca.2011.12.018.

391

22. Zhang, L.J., Kim, Y.M., Jung, H., Wan, J.M., and Jun, Y.S. Effects of salinity-induced

392

chemical reactions on biotite wettability changes under geologic CO2 sequestration

393

conditions Environmental Science & Technology Letters 2016, 3 (3), 92-97, doi:

394

10.1021/acs.estlett.5b00359.

395

23. Pan, B., Li, Y.J., Wang, H.Q., Jones, F., and Iglauer, S. CO2 and CH4 wettabilities of

396

organic-rich

shale.

Energy

&

397

10.1021/acs.energyfuels.7b02535.

Fuels

2018,

32

(2),

1914

-

1922,

doi:

22 ACS Paragon Plus Environment

Page 23 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

398 399

Energy & Fuels

24. Kula, U., and Prasad, M. Specific surface area and pore-size distribution in clays and shales. Geophysical Prospecting 2013, 61 (2), 341 - 362, doi: 10.1111/1365-2478.12028.

400

25. Ross, D.J.K. and Bustin, R.M. The importance of shale composition and pore structure

401

upon gas storage potential of shale gas reservoirs. Mar. Pet. Geol. 2009, 26 (6), 916 - 927,

402

doi: 10.1016/j.marpetgeo.2008.06.004.

403

26. Iglauer, S.; Pentland, C. H.; Busch, A. CO2 wettability of seal and reservoir rocks and the

404

implications for carbon geo-sequestration. Water Resour. Res. 2015, 51 (1) 729– 774, doi:

405

10.1002/2014WR015553.

406

27. Siddiqui, M.A.Q., Ali, S., Fei, H.X., Roshan, H. Current understanding of shale wettability:

407

A review on contact angle measurements. Earth-Science Reviews 2018, 181, 1-11, doi:

408

10.1016/j.earscirev.2018.04.002.

409

28. Borysenko, A., Clennell, B., Sedev, R., Burgar, L., Ralston, J., Raven, M., Dewhurst, D.,

410

Liu, K.Y. Experimental investigations of the wettability of clays and shales. J. Geophys.

411

Res. 2009, 114, (B7), doi: 10.1029/2008JB005928.

412

29. Cakmak, F.P., Keating, C.D. Combining catalytic microparticles with droplets formed by

413

phase coexistence: Adsorption and activity of natural clays at th activity of natural clays at

414

the aqueous/Aqueous interface. Scientific Reports 2017, 7:3215.

415

30. Innocent, C., Fagel, N., Hillaire-Marcel, C. Sm-Nd isotope systematics in deep-sea

416

sediments: clay-size versus coarser fractions. Mar. Geol. 2000, 168, 79-87, doi:

417

10.1016/S0025-3227(00)00052-9.

418

31. Al-Yaseri, A.Z., Roshan, H., Zhang, Y., Rahman, T., Lebedev, M., Barifcani, A., Iglauer,

419

S. Effect of the temperature on CO2/brine/dolomite wettability: Hydrophilic versus

420

hydrophobic

surfaces.

Energy

&

Fuels

2017,

31,

6329-6333,

doi:

23 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

421

Page 24 of 31

10.1021/acs.energyfuels.7b00745.

422

32. Alnili, F., Al-Yaseri, A., Roshan, H., Rahman, T., Verall, Lebedev, M., Sarmadivaleh, M.,

423

Iglauer, S., Barifcani, A. Carbon dioxide/brine wettability of porous sandstone versus

424

solidquartz: An experimental and theoretical investigation. J. Colloid Interface Sci. 2018,

425

524, 188-194, doi: 10.1016/j.jcis.2018.04.029.

426

33. Fuerstenau, D.W., Diao, J.L., Williams, M.C. Characterization of the wettability of solid

427

particles by film flotation 1. Experimental investigation. Colloids and Surfaces 1991, 60,

428

127-144, doi: 10.1016/0166-6622(91)80273-Q.

429

34. Schmatz, J., Urai, J.L., Berg, S., Ott, H. Nanoscale imaging of pore-scale fluid-fluid-solid

430

contacts

in

sandstone.

431

10.1002/2015GL063354.

Geophys.

Res.

Lett.

2015,

42,

7,

2189-2195,

doi:

432

35. Alhamamdi, A.M., AlRatrout, A., Singh, K., Bijeljic, B., Blunt, M.J. In situ

433

characterization of mixed wettability in a reservoir rock at subsurface conditions, Scientific

434

Reports 2017, 7: 10753.

435

36. Ballah, J., Chamerois, M., Durand-Vidal, S., Malikova, N., Levitz, P., Michot, L.J. Effect

436

of chemical and geometrical parameters influencing the wettability of smectite clay films.

437

Colloids and Surfaces A 2016, 511, 255-263, doi: 10.1016/j.colsurfa.2016.10.002.

438 439

37. Roshan, H., Al-Yaseri, A.Z., Sarmadivaleh, M., Iglauer, S. On wettability of shale rocks. J. Colloid Interface Sci. 2016, 475, 104-111, doi: 10.1016/j.jcis.2016.04.041.

440

38. Al-Yaseri, A.Z., Roshan, H., Lebedev, M., Barrifcani, A., Iglauer, S. Dependence of quartz

441

wettability on fluid density, Geophys. Res. Lett. 2016, 43, 3771-3776, doi: doi:10.1002/

442

2016GL068278.

443

39. Fauziah, C.A., Al-yaseri, A.Z., Beloborodov, R., Siddiqui, M.A.Q., Lebedev, M., Parsons,

24 ACS Paragon Plus Environment

Page 25 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

444

D., Roshan, H., Barifcani, A., and Iglauer, S. Carbon dioxide/brine, nitrogen/brine, and

445

oil/brine wettability of montmorillonite, illite, and kaolinite at elevated pressure and

446

temperature, Energy & Fuels. 2018, doi: 10.1021/acs.energyfuels.8b02845.

447

40. Myshakin, E.M., Saidi, W.A., Romanov, V.N., Cygan, R.T., Jordan, K.D. Molecular

448

dynamics simulations of carbon dioxide interaction in hydrated Na-montmorillonite, J.

449

Phys. Chem. C 2013, 117, 21, 11028-11039, doi: 10.1021/jp312589s.

450

41. Šolc, R., Gerzabek, M.H., Lischka, H., Tunega, D. Wetatbility of kaolinite (001) surfaces

451



Molecular

dynamic

study,

452

10.1016/j.geoderma.2011.02.004.

Geoderma

2011,

169,

47-54,

doi:

453

42. Roshan, H., Ehsani, S., Marjo, C.E., Andersen, M.S., Acworth, R.I. Mechanisms of water

454

adsorption into partially saturated fractured shales: An experimental study. Fuel 2015, 159,

455

628 - 637, doi: 10.1016/j.fuel.2015.07.015.

456

43. Arif., M., Lebedev, M., Barifcani, A., and Iglauer, S. Influence of shale-total organic

457

content on CO2 geo-storage potential. Geophys. Res. Lett. 2017, 44 (17), 8769-8775, doi:

458

10.1002/2017GL073532.

459

44. Sang, Q., Li, Y.J, Yang, Z.H., Zhu, C.F., Yao, J., and Dong, M.Z. Experimental

460

investigation of gas production processes in shale. Int. J. Coal Geol. 2016, 159, 30 - 47,

461

doi: 10.1016/j.coal.2016.03.017.

462

45. Sang, Q., Li, Y.J., Zhu, C.F., Zhang, S.J., and Dong, M.Z. Experimental investigation of

463

shale gas production with different pressure depletion schemes. Fuel 2016, 186, 293 - 304,

464

doi: 10.1016/j.fuel.2016.08.057.

465

46. Espinoza, D.N., and Santamarina, J.C. CO2 breakthrough – Caprock sealing efficiency and

466

integrity for carbon geological storage. Int. J. Greenhouse Gas Control 2017, 66, 218 –

25 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

467 468

Page 26 of 31

229, doi: 10.1016/j.ijggc.2017.09.019. 47. Kaveh, N.S., and Wolf, A.B.K.-H. Wettability evaluation of silty shale caprocks for CO2

469

storage.

Int.

J.

Greenhouse

470

10.1016/j.ijggc.2016.04.003.

Gas

Control

2016,

49,

425-435,

doi:

471

48. Love, J.C., Estroff, L.A., Kriebel, J.K. Nuzzo, R.G., and Whitesides, G.M. Self-assembled

472

monolayers of thiolates on metals as a form of nanotechnology. Chem. Rev. 2005, 105(4),

473

1103 - 1169, doi: 10.1021/cr0300789.

474

49. Iglauer, S., Salamah, A., Sarmadivaleh, M., Liu, K.Y., and Phan, C. Contamination of silica

475

surfaces: Impact on water–CO2–quartz and glass contact angle measurements. Int. J.

476

Greenhouse Gas Control 2014, 22, 325 - 328, doi: 10.1016/j.ijggc.2014.01.006.

477

50. Song, W., Kovscek, A.R. Functionalization of micromodels with kaolinite for investigation

478

of low salinity oil-recovery processes, Lab chip 2015, 15, 3314-3325, doi:

479

10.1039/C5LC00544B.

480

51. Rao, S.M., Thyagaraj, T. Swell–compression behaviour of compacted clays under

481

chemical gradients. Canadian Geotechnical Journal 2007, 44, 5, 520-532, doi:

482

10.1139/t07-002.

483

52. Al-Yaseri, A. Z., Lebedev, M., Barifcani, A., and Iglauer, S. Receding and advancing

484

(CO2+ brine+ quartz) contact angles as a function of pressure, temperature, surface

485

roughness, salt type and salinity. The Journal of Chemical Thermodynamics 2016, 93, 416

486

- 423, doi: 10.1016/j.jct.2015.07.031.

487 488 489

53. Lander, L.M., Siewierski, L.M., Brittan, W.J., and Vogler, E.A. A systematic comparison of contact angle methods. Langmuir 1993, 9 (8), 2237 - 2239, doi: 10.1021/la00032a055. 54. Zhang, Y.Q., Nezhad, A.S., Hejazi, S.H. Geo-material surface modification of microchips

26 ACS Paragon Plus Environment

Page 27 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

490

using layer-by-layer (LbL) assembly for subsurface energy and environmental applications,

491

Lab Chip 2018, 18, 285-295, doi: 10.1039/C7LC00675F.

492

55. Wang, L-K., Chen, G.J., Han,G.H., Guo, X.Q., Guo, T.M. Experimental study on the

493

solubility of natural gas components in water with or without hydrate inhibitor, Fluid Phase

494

Equilib. 2003, 207 (1-2), 143-154, doi: 10.1016/S0378-3812(03)00009-8.

495

56. Swanson, B.F. Rationalizing the influence of crude oil wetting on reservoir fluid flow with

496

electrical resistivity behavior. Journal of Petroleum Technology 1980, doi: 10.2118/7442-

497

PA.

498

57. Pan, B., Li, Y.J, Xie, L.J., Wang, X.P., He, Q.K., Li, Y.C., Hejazi, S.H., and Iglauer, S.

499

Role of fluid density on quartz wettability. Journal of Petroleum Science and Engineering

500

2019, 172, 511-516, doi: 10.1016/j.petrol.2018.09.088.

501

58. Arif, M., Al-Yaseri, A.Z., Barifcani, A., Lebedev, M., and Iglauer, S. Impact of pressure

502

and temperature on CO2–brine–mica contact angles and CO2–brine interfacial tension:

503

Implications for carbon geo-sequestration. J. Colloid Interface Sci. 2016, 462, 208 - 215,

504

doi: 10.1016/j.jcis.2015.09.076.

505

59. Arif, M., Barifcani, A., Lebedev, M., and Iglauer, S. Structural trapping capacity of oil-wet

506

caprock as a function of pressure, temperature and salinity. Int. J. Greenhouse Gas Control

507

2016, 50, 112 - 120, doi: 10.1016/j.ijggc.2016.04.024.

508

60. Iglauer, S., Mathew, M.S., and Bresme, F. Molecular dynamics computations of brine–

509

CO2 interfacial tensions and brine–CO2–quartz contact angles and their effects on structural

510

and residual trapping mechanisms in carbon geo-sequestration. J. Colloid Interface Sci.

511

2012, 386 (1), 15, 405-414, doi: 10.1016/j.jcis.2012.06.052.

512

61. Iglauer, S. CO2-water-rock wettability: Variability, influencing factors, and implications

27 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

513

for CO2 geostorage. Acc. Chem. Res.

514

10.1021/acs.accounts.6b00602.

Page 28 of 31

2017, 50 (5), 1134 - 1142, doi:

515

62. Chen, C., Wan, J.M., Li, W.Z., Song, Y.C. Water contact angles on quartz surfaces under

516

supercritical CO2 sequestration conditions: Experimental and molecular dynamics

517

simulation studies. Int. J. Greenhouse Gas Control 2015, 42, 655 – 665, doi:

518

10.1016/j.ijggc.2015.09.019.

519

63. Liang, Y.F., Tsuji, S., Jia, J.H., Tsuji, T. and Toshifumi Matsuoka, T. Modeling

520

CO2−water−mineral wettability and mineralization for carbon geosequestration. Acc.

521

Chem. Res. 2017, 50, 1530−1540, doi: 10.1021/acs.accounts.7b00049.

522

64. Arif, M., Barrifcani, A., and Iglauer, S. Solid/CO2 and solid/water interfacial tensions as a

523

function of pressure, temperature, salinity and mineral type: Implications for CO2-

524

wettability and CO2 geo-storage. Int. J. Greenhouse Gas Control 2016, 53, 263-273, doi:

525

10.1016/j.ijggc.2016.08.020.

526

65. Liu, Y.L., Li, H.Z., and Okuno, R. Measurements and modeling of interfacial tension for

527

CO2/CH4/brine systems under reservoir conditions. Industrial & Engineering Chemistry

528

Research 2016, 55, 48, 12358-12375, doi: 10.1021/acs.iecr.6b02446.

529

66. Pinon, A.V.; Wierez-Kien, M.; Cracium, A.D.; Beyer, N.; Gallani, J.L., and Rastei, M.V.

530

Thermal effects on van der Waals adhesive forces. Physical Review B 2016, 93 (3), 035424.

531

67. Sayyouh, M.H., Dahab, A.S., Omar, A.E. Effect of clay content on wettability of sandstone

532

reservoirs. Journal of Petroleum Science and Engineering 1990, 4 (2), 119 - 125,

533

doi.org/10.1016/0920-4105(90)90020-4.

534

68. Lebedeva, E.V., and Fogden, A. Micro-CT and wettability analysis of oil recovery from

535

sand packs and the effect of waterflood salinity and kaolinite. Energy & Fuels 2011, 25

28 ACS Paragon Plus Environment

Page 29 of 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

536 537 538

Energy & Fuels

(12), 5683 - 5694, doi: 10.1021/ef201242s. 69. Lebedeva, E.V., and Fogden, A. Adhesion of oil to kaolinite in water. Environ. Sci. Technol. 2010, 44 (24), 9470 - 9475, doi: 10.1021/es102041b.

539

70. Chiquet, P., Broseta, D., and Thibeau, S. Wettability alteration of caprock minerals by

540

carbon dioxide. Geofluids 2007, 7, 112–122, doi: 10.1111/j.1468-8123.2007.00168.x.

541

71. Arif, M., Jones, F., Barificani, A., Iglauer, S. Electrochemical investigation of the effect of

542

temperature, salinity, and salt type on brine/mineral interfacial properties. Int. J.

543

Greenhouse Gas Control 2017, 59, 136-147, doi: 10.1016/j.ijggc.2017.02.013.

544

72. Vane, L.M., Zang, G.M. Effect of aqueous phase properties on clay particle zeta potential

545

and electro-osmotic permeability: Implications for electro-kinetic soil remediation

546

processes. J. Hazard. Mater. 1997, 55, 1-22, doi: 1 0.1016/S0304-3894(97)00010-1.

547

73. Cagnola, A., Li, Z., Roshan, H., and Masoumi, H. Microstructural Evolution of Organic

548

Matter-Rich Shales by Ionic Solutions. 51st U.S. Rock Mechanics/Geomechanics

549

Symposium,

550

https://www.onepetro.org/conference-paper/ARMA-2017-0138.

25-28

June,

San

Francisco,

California,

USA.

2017,

551

74. Rezaei, K.A., Hamouda, A.A. Effect of fatty acids, water composition and pH on the

552

wettability alteration of calcite surface. Journal of Petroleum Science and Engineering

553

2006, 50, 2, 140-150, doi: 10.1016/j.petrol.2005.10.007.

554

75. Tabrizy., V.A., Denoyel., R., and Hamouda, A.A. Characterization of wettability alteration

555

of calcite, quartz and kaolinite: Surface energy analysis. Colloids Surf., A 2011, 384, 98 –

556

108, doi: 10.1016/j.colsurfa.2011.03.021.

557

76. Dlapa, P., Doerr, S.H., Lichner, Ľ., Šír, M., and Tesař, M. Effect of kaolinite and Ca-

558

montmorillonite on the alleviation of soil water repellency. Plant, Soil and Environment

29 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

559

Page 30 of 31

2004, 50 (8), 358 - 363.

560

77. Iglauer, S., and Lebedev, M. High pressure-elevated temperature x-ray micro-computed

561

tomography for subsurface applications. Adv. Colloid Interface Sci. 2018, doi:

562

10.1016/j.cis.2017.12.009.

563

78. Tombácz, E., and Szekeres, M. Surface charge heterogeneity of kaolinite in aqueous

564

suspension in comparison with montmorillonite. Appl. Clay Sci. 2006, 34, 105 - 124, doi:

565

10.1016/j.clay.2006.05.009.

566 567

79. Wan, J.M., and Tokunaga, T.K. Partitioning of clay colloids at air-water interfaces. J. Colloid Interface Sci. 2002, 247 (1), 54-61, doi: 10.1006/jcis.2001.8132.

568

30 ACS Paragon Plus Environment

Page 31 of 31

50 Brine advancing contact angle [º] of 1.5 wt% NaCl-CH4-solid

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Clean, 300 K

45

Clean, 323 K

40

Kaolinite coated, 300 K

35

Kaolinite coated, 323 K Montmorillonite coated, 300 K

30

Montmorillonite coated, 323 K

25 20 15 10 5 0 0

5

10 P [MPa]

ACS Paragon Plus Environment

15

20