Introduction to Borehole Stability Analysis

Borehole stability is critical to drilling operations in the oil and gas, geological storage, and geothermal industries. This eLearning course provides the core knowledge required to analyze, predict, and prevent wellbore instabilities, ensuring safe, efficient, and cost-effective drilling.

In this eLearning course, you will explore the key principles of borehole stability, including how drilling alters in-situ stresses and generates stress concentrations around the wellbore. While learning their theoretical concepts and prevention strategies, you will examine how these changes contribute to key drilling challenges, such as induced tensile cracks and breakouts. The course also covers the techniques for determining the safe mud weight window, mitigating geomechanical risks, and optimizing drilling fluid weight and casing design to maintain well integrity.

By combining theory with real-world applications, and numerous quizzes and exercises, this course equips you with the core knowledge needed to prevent costly issues, such as wellbore collapse, stuck pipe, and loss of circulation— problems that contribute to non-productive time, environmental risks, and financial loss. There is also a brief introduction to advanced methodologies for analyzing and designing stable wells, laying the groundwork for tackling more complex geomechanical challenges in the future. This eLearning course continues from the Characterization of In-Situ Stresses Core course, focusing on determination of maximum horizontal stress and using case studies to provide insights on the characterization of the full stress tensor.

Target Audience

Geoscientists, petrophysicists, completion and drilling engineers, or anyone involved in unconventional reservoir development.

You Will Learn

• Define borehole instability and its significance in drilling operations
• Identify how drilling alters rock geometry, stresses, and pore pressure, potentially leading to rock failure
• Recognize the orientations of stress components in the radial, tangential, and longitudinal directions
• Investigate the causes and mechanisms of mud loss during drilling, focusing on creating tensile fractures and their operational impact
• Explain the concept of shear failure in rocks
• Recognize the importance of mud pressure in stabilizing borehole walls and preventing shear failure
• Recognize the concept of a safe mud window for balanced drilling operations and differentiate between balanced, underbalanced, and overbalanced drilling
• Describe the reasons for drilling deviated or non-vertical wells in real-world operations
• Appreciate the importance of selecting appropriate constitutive models and failure criteria based on the specific rock type and in-situ conditions
• Describe the thermal interactions between drilling fluid and formation rock
  and assess the impact of temperature variations on compressive stresses, shear failure, and the risks of hydraulic fracturing
• Describe fluid movement mechanisms, such as hydraulic diffusion, advection, chemical diffusion, chemical osmosis, and diffusion osmosis, and assess how these processes affect formation stability, permeability, and well productivity

Course Content

• Introduction to Challenges of Unstable Drilling
• Mechanisms of Borehole Instability
• Stress Disturbance Induced by Drilling
• Tensile Failure and Mud Loss
• Shear Failure Induced by Drilling
• Minimum Acceptable Mud Pressure
• Safe Mud Window and Casing Installation
• Deviated Boreholes
• Advanced Methods for Borehole Stability Analysis

Product Details