Lecture on Introduction to Logging in Petroleum Industry

Speaker Introduction

• Dr. Robbie: 5 years experience in the petroleum industry.
  • PhD from North Carolina State University.
  • Master’s degree from Egypt.
  • Lecturing experience in universities and community colleges in the USA.
  • Various positions and experience globally in the petroleum industry.

Overview and Links to Previous Topics

• Continuation from the previous lecture on logging.
• Importance of logging in understanding unconventional reservoir.
• Logging as part of drilling and evaluation segment.

Segments of the Oil and Gas Industry

1. Identification, Drilling, and Evaluation
   • Logging falls here for evaluation.
2. Completion and Production
3. Field Management

Types of Logging

• Wireline Logging
  • Conducted after drilling, with only drilling fluid in the wellbore.
  • Uses a wire equipped with conductors to send and receive data.
• Logging While Drilling (LWD)
  • Logs while drilling, tools integrated with the bottom hole assembly.
  • Preferred for horizontal, high-angle, or deviated wells.

Wireline Logging

• Post-drilling (before casing or cementing).
• Conducted in an open hole environment.

LWD

• Integrated with drilling operations.
• Tools measure while drilling.

Key Measurements in Logging

1. Wellbore Diameter
   • Logging tools to measure diameter at various depths.
   • Important for understanding wellbore stability and cementing volume.
2. Formation Porosity
   • Indication of the void space within the formation where hydrocarbon can reside.
3. Lithology (Formation Type)
   • Determine if the reservoir is sandstone, limestone, dolomite, etc.
4. Fluid Saturation
   • Determine the proportions of water and hydrocarbons.
5. Rock Mechanics
   • Essential for designing fracturing operations and evaluating rock strength.

Clays and Shales: Importance and Distinction

• Clays are detrimental to reservoir quality, clogging pore spaces and reducing porosity.
• Key Distinction: Every clay is a shale but not every shale is clay.
  • Important for understanding unconventional reservoirs.
• Clay minerals like potassium and thorium are radioactive and can clog pore spaces, reducing reservoir quality.

Key Logging Tools and Their Measurements

1. Caliper Tool: Measures borehole size.
2. Gamma Ray Tool: Identifies clay content through radioactivity.
3. Neutron Porosity Tool: Measures formation porosity through hydrogen count (related to water and hydrocarbons in pores).
4. Density Tool: Determines lithology and formation density by measuring electron density.
5. Resistivity Tool: Measures fluid saturation through conductivity (water is conductive, hydrocarbons are resistive).
6. Sonic Tool: Measures rock mechanical properties using sound waves to determine compressibility and shear strength.

Practical Applications of Tools

• Tools are selected based on specific needs and conditions of the well (e.g., wireline for vertical wells, LWD for horizontal wells).
• Each tool serves a unique purpose in overall formation evaluation, leading to optimal reservoir management and production planning.

Conclusion

• The array of logging tools and measurements provide critical data for effective reservoir management.
• Understanding physical properties and detection methods is essential for interpreting logging data.
• Engineers must be inquisitive, always asking questions to understand and optimize logging and evaluation techniques.

For more details or questions, Dr. Robbie's email was shared for further engagement and clarity on specific topics.