During the drilling of shale formations, drilling fluids can intrude into the wellbore, raise the pore pressure, and lead to wellbore instability. Based on the thermodynamic theory, a new model was established to calculate pore pressure. The model considers the effects of solute diffusion and solution convection and conducts sensitivity analyses. The results show that the drilling fluid activity significantly affects the pore pressure distribution. The pore pressure under high drilling fluid activity will increase rapidly in the early stage. Low drilling fluid activity can effectively suppress the growth of pore pressure. And a low effective diffusion coefficient of solute and a high membrane efficiency also help to reduce pore pressure. Therefore, reducing drilling fluid activity should be conducted in priority in drilling fluid design. Lowering its solute effective diffusion coefficient and increasing its viscosity can also be considered as auxiliary methods.

References

References
1.
Rahman
,
M. K.
,
Naseby
,
D.
, and
Rahman
,
S. S.
,
2000
, “
Borehole Collapse Analysis Incorporating Time-Dependent Pore Pressure Due to Mud Penetration in Shales
,”
J. Petrol. Sci. Eng.
,
28
(
1
), pp.
13
31
.
2.
AL-Bazali
,
T.
,
2013
, “
The Impact of Water Content and Ionic Diffusion on the Uniaxial Compressive Strength of Shale
,”
Egypt. J. Pet.
,
22
(
2
), pp.
249
260
.
3.
Cosenza
,
P.
,
Ghoreychi
,
M.
,
Marsily
,
G. D.
,
Vasseur
,
G.
, and
Violette
,
S.
,
2002
, “
Theoretical Prediction of Poroelastic Properties of Argillaceous Rocks From In Situ Specific Storage Coefficient
,”
Water Resour. Res.
,
38
(
10
), p.
25
.
4.
Gao
,
Q.
,
Cheng
,
Y.
,
Yan
,
C.
,
Jiang
,
L.
, and
Han
,
S.
,
2018
, “
Initiation Pressure and Corresponding Initiation Mode of Drilling Induced Fracture in Pressure Depleted Reservoir
,”
ASME J. Energy Resour. Technol.
,
141
(
1
), p.
012901
.
5.
Wild
,
K. M.
, and
Amann
,
F.
,
2018
, “
Experimental Study of the Hydro-Mechanical Response of Opalinus Clay—Part 1: Pore Pressure Response and Effective Geomechanical Properties Under Consideration of Confinement and Anisotropy
,”
Eng. Geol.
,
237
, pp.
32
41
.
6.
Bol
,
G. M.
,
Wong
,
S.-W.
,
Davidson
,
C. J.
, and
Woodland
,
D. C.
,
1994
, “
Borehole Stability in Shales
,”
SPE Drill. Completion
,
9
(
2
), pp.
87
94
.
7.
Kiran
,
R.
, and
Salehi
,
S.
,
2016
, “
Thermoporoelastic Modeling of Time-Dependent Wellbore Strengthening and Casing Smear
,”
ASME J. Energy Resour. Technol.
,
139
(
2
), p.
022903
.
8.
Chen
,
C.
,
Gao
,
S.
,
Sun
,
Y.
,
Guo
,
W.
, and
Li
,
Q.
,
2017
, “
Research on Underground Dynamic Fluid Pressure Balance in the Process of Oil Shale In-Situ Fracturing-Nitrogen Injection Exploitation
,”
ASME J. Energy Resour. Technol.
,
139
(
3
), p.
032908
.
9.
Chenevert
,
M. E.
,
1970
, “
Shale Alteration by Water Adsorption
,”
J. Petrol. Technol.
,
22
(
9
), pp.
141
148
.
10.
Sherwood
,
J. D.
,
1995
, “
Ionic Transport in Swelling Shale
,”
Adv. Colloid Interfac.
,
61
(
95
), pp.
51
64
.
11.
Heidug
,
W. K.
, and
Wong
,
S. W.
,
1996
, “
Hydration Swelling of Water-Absorbing Rocks: A Constitutive Model
,”
Int. J. Numer. Anal. Met.
,
20
(
6
), pp.
403
430
.
12.
Lomba
,
R. F.
,
Chenevert
,
M. E.
, and
Sharma
,
M. M.
,
2000
, “
The Role of Osmotic Effects in Fluid Flow Through Shales
,”
J. Petrol. Sci. Eng.
,
25
(
1–2
), pp.
25
35
.
13.
Ghassemi
,
A.
, and
Diek
,
A.
,
2002
, “
Porothermoelasticity for Swelling Shales
,”
J. Petrol. Sci. Eng.
,
34
(
1
), pp.
123
135
.
14.
Yu
,
M.
,
Chenevert
,
M. E.
, and
Sharma
,
M. M.
,
2003
, “
Chemical-Mechanical Wellbore Instability Model for Shales: Accounting for Solute Diffusion
,”
J. Petrol. Sci. Eng.
,
38
(
3–4
), pp.
131
143
.
15.
Bader
,
S.
, and
Kooi
,
H.
,
2005
, “
Modelling of Solute and Water Transport in Semi-Permeable Clay Membranes: Comparison With Experiments
,”
Adv. Water Resour.
,
28
(
3
), pp.
203
214
.
16.
Chen
,
G.
,
Ewy
,
R. T.
, and
Yu
,
M.
,
2010
, “
Analytic Solutions With Ionic Flow for a Pressure Transmission Test on Shale
,”
J. Petrol. Sci. Eng.
,
72
(
1
), pp.
158
165
.
17.
Dokhani
,
V.
,
Yu
,
M.
,
Takach
,
N. E.
, and
Bloys
,
B.
,
2015
, “
The Role of Moisture Adsorption in Wellbore Stability of Shale Formations: Mechanism and Modeling
,”
J. Nat. Gas Sci. Eng.
,
27
, pp.
168
177
.
18.
Liu
,
C.
,
Hoang
,
S. K.
,
Tran
,
M. H.
,
Abousleiman
,
Y. N.
, and
Ewy
,
R. T.
,
2017
, “
Poroelastic Dual-Porosity Dual-Permeability Simulation of Pressure Transmission Test on Chemically Active Shale
,”
J. Eng. Mech.
,
143
(
6
), p.
04017016
.
19.
Malusis
,
M. A.
,
Shackelford
,
C. D.
, and
Maneval
,
J. E.
,
2012
, “
Critical Review of Coupled Flux Formulations for Clay Membranes Based on Nonequilibrium Thermodynamics
,”
J. Contam. Hydrol.
,
138–139
(
2
), pp.
40
59
.
20.
Ghassemi
,
A.
, and
Diek
,
A.
,
2003
, “
Linear Chemo-Poroelasticity for Swelling Shales: Theory and Application
,”
J. Petrol. Sci. Eng.
,
38
(
3–4
), pp.
199
212
.
21.
Yan
,
B.
,
Wang
,
Y.
, and
Killough
,
J. E.
,
2016
, “
Beyond Dual-Porosity Modeling for the Simulation of Complex Flow Mechanisms in Shale Reservoirs
,”
Computat. Geosci.
,
20
(
1
), pp.
69
91
.
22.
Malusis
,
M. A.
, and
Shackelford
,
C. D.
,
2002
, “
Coupling Effects During Steady-State Solute Diffusion Through a Semipermeable Clay Membrane
,”
Environ. Sci. Technol.
,
36
(
6
), pp.
1312
1319
.
23.
Malusis
,
M. A.
, and
Daniyarov
,
A. S.
,
2016
, “
Membrane Efficiency and Diffusive Tortuosity of a Dense Prehydrated Geosynthetic Clay Liner
,”
Geotext. Geomembranes
,
44
(
5
), pp.
719
730
.
24.
Malusis
,
M. A.
, and
Shackelford
,
C. D.
,
2002
, “
Chemico-Osmotic Efficiency of a Geosynthetic Clay Liner
,”
J. Geotech. Geoenviron.
,
128
(
2
), pp.
97
106
.
25.
Dokhani
,
V.
,
Yu
,
M.
,
Gao
,
C.
, and
Bloys
,
J.
,
2017
, “
Investigating the Relation Between Sorption Tendency and Hydraulic Properties of Shale Formations
,”
ASME J. Energy Resour. Technol.
,
140
(
1
), p.
012902
.
26.
Yu
,
M.
,
2002
, “
Chemical and Thermal Effects on Wellbore Stability of Shale Formations
,” Ph.D. thesis,
University of Texas at Austin
,
Austin, TX
.
27.
van Oort
,
E.
,
Hale
,
A. H.
,
Mody
,
F. K.
, and
Roy
,
S.
,
1996
, “
Transport in Shales and the Design of Improved Water-Based Shale Drilling Fluids
,”
SPE Drill. Completion
,
11
(
3
), pp.
137
246
.
28.
Dokhani
,
V.
,
2014
, “
The Effects of Chemical Adsorption on Wellbore Stability in Transversely Isotropic Shale Formations
,” Ph.D. thesis,
The University of Tulsa
,
Tulsa, OK
.
29.
Zheng
,
S.
, and
Yang
,
D.
,
2016
, “
Experimental and Theoretical Determination of Diffusion Coefficients of CO2-Heavy Oil Systems by Coupling Heat and Mass Transfer
,”
ASME J. Energy Resour. Technol.
,
139
(
2
), p.
022901
.
30.
Yeung
,
A. T.
,
1990
, “
Coupled Flow Equations for Water, Electricity and Ionic Contaminants Through Clayey Soils Under Hydraulic, Electrical, and Chemical Gradients
,”
J. Non-Equil. Thermodyn.
,
15
(
3
), pp.
247
267
.
31.
Yeung
,
A. T.
, and
Mitchell
,
J. K.
,
1993
, “
Coupled Fluid, Electrical, and Chemical Flows in Soil
,”
Geotechnique
,
43
(
1
), pp.
121
134
.
32.
Sherwood
,
J. D.
, and
Craster
,
B.
,
2000
, “
Transport of Water and Ions Through a Clay Membrane
,”
Adv. Colloid Interfac.
,
230
(
2
), pp.
349
358
.
33.
Wang
,
Z.
, and
Chen
,
Y.
,
2018
, “
Finite Element Analysis of Thermally Induced Stresses in the Near-Wellbore Region During Invasion of Mud Into Fractures
,”
ASME J. Energy Resour. Technol.
,
140
(
5
), p.
052909
.
34.
Onsager
,
L.
,
1931
, “
Reciprocal Relations in Irreversible Processes I
,”
Phys. Rev.
,
38
(
37
), pp.
405
426
.
35.
Song
,
J.
,
Yuan
,
Y.
,
Gu
,
S.
,
Yang
,
X.
,
Yue
,
Y.
, and
Cai
,
J.
,
2017
, “
2D Numerical Simulation of Improving Wellbore Stability in Shale Using Nanoparticles Based Drilling Fluid
,”
Energies
,
10
(
5
), p.
651
.
36.
Ma
,
T.
,
Chen
,
P.
,
Zhang
,
Q.
, and
Zhao
,
J.
,
2016
, “
A Novel Collapse Pressure Model With Mechanical-Chemical Coupling in Shale Gas Formations With Multi-Weakness Planes
,”
J. Nat. Gas Sci. Eng.
,
36
, pp.
1151
1177
.
37.
Ghassemi
,
A.
,
Tao
,
Q.
, and
Diek
,
A.
,
2009
, “
Influence of Coupled Chemo-Poro-Thermoelastic Processes on Pore Pressure and Stress Distributions Around a Wellbore in Swelling Shale
,”
J. Petrol. Sci. Eng.
,
67
(
1
), pp.
57
64
.
38.
Yew
,
C. H.
,
Chenevert
,
M. E.
,
Wang
,
C. L.
, and
Osisanya
,
S.
,
1990
, “
Wellbore Stress Distribution Produced by Moisture Adsorption
,”
SPE Drill. Eng.
,
5
(
4
), pp.
311
316
.
39.
Wang
,
C. L.
,
1992
, “
On Stability of a Deviated Wellbore in Shale Rocks
,” Ph.D. thesis,
University of Texas at Austin
,
Austin, TX
.
40.
Vásárhelyi
,
B.
, and
Ván
,
P.
,
2006
, “
Influence of Water Content on the Strength of Rock
,”
Eng. Geol.
,
84
(
1–2
), pp.
70
74
.
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