Analysis of small temperature oscillation in a deformable solid matrix containing a spherical cavity filled with a compressible liquid – Analytical solutions for damage initiation induced by pore pressure variation

2018 ◽  
Vol 129 ◽  
pp. 1-20 ◽  
Author(s):  
Heraldo S. Da Costa Mattos ◽  
Luciana P. Teixeira ◽  
Maria Laura Martins-Costa
Keyword(s):  
Pore Pressure ◽  
Analytical Solutions ◽  
Spherical Cavity ◽  
Temperature Oscillation ◽  
Compressible Liquid ◽  
Pressure Variation ◽  
Solid Matrix ◽  
Deformable Solid ◽  
Small Temperature ◽  
Damage Initiation

scholarly journals Analytical solutions of compacting flow past a sphere

2014 ◽  
Vol 746 ◽  
pp. 466-497 ◽  
Author(s):  
John F. Rudge
Keyword(s):  
Analytical Solutions ◽  
Stokes Flow ◽  
Solid Matrix ◽  
Rigid Sphere ◽  
Deformable Solid ◽  
Two Phase ◽  
Low Viscosity ◽  
Flow Past ◽  
Phase Medium ◽  
Flow Past A Sphere

AbstractA series of analytical solutions are presented for viscous compacting flow past a rigid impermeable sphere. The sphere is surrounded by a two-phase medium consisting of a viscously deformable solid matrix skeleton through which a low-viscosity liquid melt can percolate. The flow of the two-phase medium is described by McKenzie’s compaction equations, which combine Darcy flow of the liquid melt with Stokes flow of the solid matrix. The analytical solutions are found using an extension of the Papkovich–Neuber technique for Stokes flow. Solutions are presented for the three components of linear flow past a sphere: translation, rotation and straining flow. Faxén laws for the force, torque and stresslet on a rigid sphere in an arbitrary compacting flow are derived. The analytical solutions provide instantaneous solutions to the compaction equations in a uniform medium, but can also be used to numerically calculate an approximate evolution of the porosity over time whilst the porosity variations remain small. These solutions will be useful for interpreting the results of deformation experiments on partially molten rocks.

Wellbore Integrity: An Integrated Experimental and Numerical Study to Investigate Pore Pressure Variation during Cement Hardening under Downhole Conditions

SPE Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Weicheng Zhang ◽  
Andreas Eckert ◽  
Steven Hilgedick ◽  
Harvey Goodman ◽  
Meng Meng
Keyword(s):  
Pore Pressure ◽  
Numerical Study ◽  
Pressure Variation ◽  
The State ◽  
Numerical Results ◽  
Von Mises Stress ◽  
Fluid Loss ◽  
Wellbore Integrity ◽  
State Of Stress ◽  
Pressure Decrease

Summary Understanding the cement hardening process and determining the development of the state of stress in the cement under specific downhole conditions are challenging but fundamental requirements to perform an accurate prediction of wellbore integrity. As an essential component of the state of stress, the temporal variation of cement pore pressure is a critical factor that affects the occurrence of cement failure. In this study, we present a novel laboratory setup to measure the cement pore pressure variation during hardening under representative downhole conditions, including the pressure, temperature, and water exchange between the cement and formation. The pore pressure measurements are further incorporated with a staged finite element analysis (FEA) approach to investigate the state of stress development during cement hardening and to evaluate cement failure under different operations and after different wait-on-cement (WOC) periods. The laboratory measurements show that the external water supply from the formation significantly impedes the pore pressure drop in the cement. The numerical results indicate that the accelerated pore pressure decrease obtained without considering downhole conditions elevates the contact pressure at the cement-formation interfaces significantly and moderately increases the von Mises stress in the cement. The numerical results further predict that the accelerated pore pressure decrease leads to an overestimation of shear failure during pressure testing and steamflooding operations but an underestimation of debonding failure during severe fluid loss and injection-related cooling processes. Based on the results of the integrated laboratory and numerical approach, qualitative and quantitative suggestions are provided for field operations to inhibit wellbore integrity risk during the wellbore life cycle.

scholarly journals Pore pressure variation at constant confining stress on water–oil and silica nanofluid–oil relative permeability

2018 ◽  
Vol 9 (3) ◽  
pp. 2065-2079 ◽  
Author(s):  
Caspar Daniel Adenutsi ◽  
Zhiping Li ◽  
Fengpeng Lai ◽  
Anthony Edem Hama ◽  
Wilberforce Nkrumah Aggrey
Keyword(s):  
Pore Pressure ◽  
Relative Permeability ◽  
Pressure Variation ◽  
Confining Stress

Evaluation of Induced Thermal Pressurization in Clearwater Shale Caprock in Electromagnetic Steam-Assisted Gravity-Drainage Projects

SPE Journal ◽  
2013 ◽  
Vol 19 (03) ◽  
pp. 443-462 ◽  
Author(s):  
Sahar Ghannadi ◽  
Mazda Irani ◽  
Rick Chalaturnyk
Keyword(s):  
Pore Pressure ◽  
Analytical Solutions ◽  
Oil Sands ◽  
Shear Failure ◽  
Gravity Drainage ◽  
Hydraulic Fractures ◽  
Low Permeability ◽  
Steam Assisted Gravity Drainage ◽  
Thermal Pressurization ◽  
Shale Formation

Summary Inductive methods, such as electromagnetic steam-assisted gravity drainage (EM-SAGD), have been identified as technically and economically feasible recovery methods for shallow oil-sands reservoirs with overburdens of more than 30 m (Koolman et al. 2008). However, in EM-SAGD projects, the caprock overlying oil-sands reservoirs is also electromagnetically heated along with the bitumen reservoir. Because permeability is low in Alberta thermal-project caprock formations (i.e., the Clearwater shale formation in the Athabasca deposit and the Colorado shale formation in the Cold Lake deposit), the pore pressure resulting from the thermal expansion of pore fluids may not be balanced with the fluid loss caused by flow and the fluid-volume changes resulting from pore dilation. In extreme cases, the water boils, and the pore pressure increases dramatically as a result of the phase change in the water, which causes profound effective-stress reduction. After this condition is established, pore pressure increases can lead to shear failure of the caprock, the creation of microcracks and hydraulic fractures, and subsequent caprock integrity failure. It is typically believed that low-permeability caprocks impede the transmission of pore pressure from the reservoir, making them more resistant to shear failure (Collins 2005, 2007). In cases of induced thermal pressurization, low-permeability caprocks are not always more resistant. In this study, analytical solutions are obtained for temperature and pore-pressure rises caused by the constant EM heating rate of the caprock. These analytical solutions show that pore-pressure increases from EM heating depend on the permeability and compressibility of the caprock formation. For stiff or low-compressibility media, thermal pressurization can cause fluid pressures to approach hydrostatic pressure, and shear strength to approach zero for low-cohesive-strength units of the caprock (units of the caprock with high silt and sand percentage) and sections of the caprock with pre-existing fractures with no cohesion.

Resistivity survey results related to the measurement of pore pressure variation in sea dyke

2011 ◽  
Author(s):  
Sung-Ho Song ◽  
Gyu-Sang Lee ◽  
Jin-Sung Kim ◽  
Jong-Hak Choi ◽  
In-Ky Cho
Keyword(s):  
Pore Pressure ◽  
Pressure Variation ◽  
Resistivity Survey ◽  
Survey Results

Effect of Pore Pressure Variation on Borehole Stability of Drilling in Sandstone Reservoir

2012 ◽  
Vol 577 ◽  
pp. 163-166
Author(s):  
Yu Wei Li ◽  
Jia Liu ◽  
Chao Yang Hu ◽  
Shuang Li ◽  
Yu Liu
Keyword(s):  
Pore Pressure ◽  
Effective Stress ◽  
Drilling Fluid ◽  
Calculation Model ◽  
Pressure Variation ◽  
Stress Factor ◽  
Borehole Stability ◽  
Porosity Variation ◽  
Sandstone Reservoir ◽  
Variation Model

Considering pore pressure variation of sidewall rock, which is caused by drilling fluid filtering, the porosity variation model of sidewall rock in sandstone reservoir and effective stress factor variation model are established, and according to relationship between pore pressure and total volume strain of sandstone, the calculation model of safe window of drilling fluid density on sandstone reservoir, with which considered variation of porosity and effective stress factor are finally established. Applying the calculation of this model shows that: with increased function of drilling fluid filtering, which is as increased as pore pressure of sidewall rock, caving pressure that ensures well hole stability is increased, fracturing pressure is decreased, safe window of drilling fluid is narrowing, and that is against of safety drilling.

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