Wellbore Stability
Training Course
Wellbore Stability
Introduction to petroleum geomechanics and applications
Stress tensor, strain tensor, Mohr circle for stress and strain, pore pressure, effective stress, Equilibrium equation
Stress-strain relationship, Hooke’s law, Rock Stiffness
Mechanical properties from laboratory testing
- Core representativeness and influence of sample size, core alteration, shale disturbance, core handling, sample preparation
- Rock tensile tests, Unconfined Compressive Strength (UCS), triaxial test, hydrostatic tests, direct shear test, odometer test, TWC test, shale testing
- Strength profiling
In-situ stress regimes, Overburden stress, min and max horizontal stress, and pore pressure, in situ stress directions, overpressure mechanisms, stress limits at depth, stress polygon
1D and 3D Mechanical Earth Models
Rock properties from wireline logs and geophysical exploration
- Density, Porosity, elastic modulus, poisson's ratio, UCS, Strength estimation from physical properties
Stress with constant and variable pore pressure around boreholes
Wellbore stability during drilling
- Borehole failure criteria
- Borehole breakouts
- Stability of vertical and slanted wells
- Lost circulation
- Mud window
Wellbore stability during drilling
- Stability of slanted wells
- Thermal effects and borehole stability
- Effect of mud diffusion in the formation on borehole shearing and lost circulation
- Effect of rock anisotropy
- Effect of reservoir pressure depletion on infill drilling
- Surge and swab effect
Shale Drilling
- Shale behavior
- shale damage and stress around borehole
- Shale swelling and Geochemical effects
- Oil-base mud vs water-base mud
- Signs of geochemical vs. mechanical instability
- Trajectory choice
- Examination of shale chips and cuttings