Hydraulic Fracturing Q&A Session Notes

Jul 29, 2024

Q&A Session Summary

Introduction

  • Moderator: May Aror, senior gas and petrochemicals engineering student.
  • Guest Speaker: Dr. Ahmed, 20 years in energy and petroleum industry. Specialized in production enhancement services, including acidizing, hydraulic fracturing, J mechanics, carbon capture, etc.
  • Experience: Dr. Ahmed led projects for Apache, CH, PP, Shell, Totel. Research manager at Military Search Hub and assistant professor at Marita College.

Key Topics Discussed

Increasing Formation Permeability

Permeability and Porosity: - Original state of reservoir. Important parameters: porosity and permeability. - Conventional reservoir (10-25%) vs. unconventional reservoir (<10% porosity)

  • Improvement Techniques:
    • No natural way to improve permeability without intervention.
    • Hydraulic fracturing bypasses formation damage, doesn’t improve permeability directly.
    • Acidizing (e.g., matrix acidizing) can improve permeability.

Treatment Fluid for Hydraulic Fracturing

  • Engineered Fluid: Specially designed fluid with additives (e.g., slick water, crosslink gel) for the specific reservoir.
  • Components: Additives like proppant, KCl, gelling agent, scale inhibitor, and breaker.

Injection Rate

  • Constant injection rate is crucial for methods like G-function technique to evaluate leak-off and closure pressure.

Importance of English Proficiency in Oil and Gas Industry

  • English as the common language in oil and gas business globally.
  • Importance of improving English for career prospects.

pH of Fracture Fluids

  • All operational fluids have pH > 7 except acidizing fluids.
  • Higher pH to minimize corrosion risks.

Injection Through Production Tubing vs Coiled Tubing

  • Depends on the reservoir and well configuration: Horizontal wells may require coiled tubing.
  • Vertical or slanted wells can use production tubing.

Assignments and Quizzes

  • Watch lectures, take notes, and submit quizzes on Google Classroom.
  • Certificate will be given post final exam.
  • If issues exist with submission, it is usually a system error.

Technical Questions and Clarifications

Stress Tensors and Vectors Explanation

  • Tensor: A multidirectional quantity: scaler (0D), vector (1D), matrix (2D), and so on.
  • Principal Stresses: Overburden, minimum horizontal stress, maximum horizontal stress.
  • Stress described as tensor but individual principal stresses (overburden, horizontal, vertical) can be vectors.

Evaluating Hydraulic Fracturing

  • Evaluation of fracturing jobs done post-treatment using simulations and real-time tests.
  • Specific techniques like buildup tests to assess effects on permeability and production.

Slick Water vs Crosslink Gel

  • Slick Water: High rate, low viscosity, used for brittle shales and complex fracture networks.
  • Crosslink Gel: Higher viscosity, used for conventional sandstone to handle permeability and leak-off issues.

Permability Post-Fracturing

  • Hydraulic fracturing bypasses but does not fix or remove formation damage. Acidizing can fix formation damage by dissolving obstructions.

Participant Questions and Managing Assignments

  • Clarification on specific chemical additives and roles in fracturing fluids.
  • Importance of joining Google Classroom for assignments and updates.
  • Stress ranks and constants in fracture models.

Conclusion

  • Importance of notes and practical experience for effective learning.
  • Engage with content and complete assignments and final exams for certification.