TY - JOUR
T1 - Poroelastic Solution for the Nonlinear Injectivity of Subsurface Rocks With Strain-Induced Permeability Variations
AU - Zhang, Wei
AU - Mehrabian, Amin
N1 - Funding Information:
The Petroleum Research Fund of the American Chemical Society under Grant 59894‐DNI9 is gratefully acknowledged. The authors wish to thank the editors and anonymous reviewers for their constructive criticism of this work.
Publisher Copyright:
©2020. American Geophysical Union. All Rights Reserved.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - Fluid injection in porous rock occurs in a variety of hydrogeological operations including wastewater disposal, CO2 sequestration, enhanced oil recovery, and geothermal energy extraction. Influx of fluid into the host rock is usually accompanied by induced permeability enhancement due to increased pore fluid pressure and consequent dilation of the pore volume. The effect would, in turn, enhance the well injectivity index. This paper presents an analytical solution to the nonlinear problem of underground fluid injection in a disk-shaped reservoir while accounting for the induced permeability enhancement. The host rock permeability is considered to depend on the rock total stress and pore fluid pressure. For this purpose, the rock stress is formulated as a nonlocal function of disturbances in the pore fluid pressure using the fundamental solution for a nucleus of strain in an elastic half space. Alongside, the nonlinear fluid transport equation that incorporates stress-sensitive rock permeability is analytically solved using a perturbation technique. The good match with finite difference solution to the same problem verifies the validity and accuracy of the perturbation solution. Parametric study on a test case problem is conducted to examine the influence of different parameters on well injectivity. Findings reveal the higher vulnerability of shallower host reservoirs to stress-induced permeability variations. The effect of rock poroelastic properties on fluid transport process is discussed.
AB - Fluid injection in porous rock occurs in a variety of hydrogeological operations including wastewater disposal, CO2 sequestration, enhanced oil recovery, and geothermal energy extraction. Influx of fluid into the host rock is usually accompanied by induced permeability enhancement due to increased pore fluid pressure and consequent dilation of the pore volume. The effect would, in turn, enhance the well injectivity index. This paper presents an analytical solution to the nonlinear problem of underground fluid injection in a disk-shaped reservoir while accounting for the induced permeability enhancement. The host rock permeability is considered to depend on the rock total stress and pore fluid pressure. For this purpose, the rock stress is formulated as a nonlocal function of disturbances in the pore fluid pressure using the fundamental solution for a nucleus of strain in an elastic half space. Alongside, the nonlinear fluid transport equation that incorporates stress-sensitive rock permeability is analytically solved using a perturbation technique. The good match with finite difference solution to the same problem verifies the validity and accuracy of the perturbation solution. Parametric study on a test case problem is conducted to examine the influence of different parameters on well injectivity. Findings reveal the higher vulnerability of shallower host reservoirs to stress-induced permeability variations. The effect of rock poroelastic properties on fluid transport process is discussed.
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U2 - 10.1029/2020WR027620
DO - 10.1029/2020WR027620
M3 - Article
AN - SCOPUS:85089838586
VL - 56
JO - Water Resources Research
JF - Water Resources Research
SN - 0043-1397
IS - 8
M1 - e2020WR027620
ER -