Fundamentals of Petroleum Geomechanics

Day 1

Fundamentals and experimental rock mechanics

• The stress tensor, units, principal stresses, strain, resolving stresses on a plane, construct Mohr's Circle and analyze stress, elasticity and elastic properties, effective stress, internal friction, cohesion, modes of rock deformation, unconfined compressive strength, Mohr-Coulomb failure
• Experimental rock mechanics, uniaxial and triaxial testing, thick wall cylinder tests, scratch testing, true triaxial tests, tensile tests, analyze results

Day 2

Stress, Pore pressure and the Mechanical Earth Model

• Principal earth stresses, regional and local stresses, World Stress Map, Andersonian classification of faults, overburden stress, horizontal stress orientation, borehole breakouts, drilling-induced tensile fractures, image logs, horizontal stress magnitudes, leak-off tests, fracture gradients
• Origins of pore pressure, methods for measurement, methods for estimation, vertical and horizontal methods, Eaton’s method, real-time approach
• Concept and construction of the Mechanical Earth Model, data requirements and types of input data

Day 3

Wellbore geomechanics and wellbore stability

• Wellbore geomechanics, state of stress in the wellbore
• Modes of rock deformation in the wellbore, the effect of well azimuth and inclination, simple calculations
• Wellbore deformation in fractured rock masses and non-classical rock failures

Day 4

Applications

• An introduction to planning for wellbore stability and real time operations
• Sand production and management, causes of sand failure, experimental evidence, an introduction to screenless completion design for sand prevention
• Hydraulic fracturing, process of hydraulic fracturing, geomechanical factors effecting fracture development and simple calculations
• Reservoir behaviour, an introduction to compaction and subsidence, well integrity, use of 4D seismic in geomechanics and the effects of injection (pressure maintenance, waste disposal and gas storage)

Day 5

Case study practical

• Working in teams, an opportunity to put into practice the geomechanics learnt during the week to design a wellbore stability plan for a proposed high angle well.