Well Integrity - Cased Hole Logging and Monitoring

Day 1

• Introduction to Well Integrity: Why Monitor Well Integrity?
• Overview: Problems causing well integrity
• Depth control in cased hole.
• Well Head Pressure Control.
  • Well Head pressure variations with time, caused by depletion, gas lift and the variations in the borehole fluid contents.
• Leak Detection tools:
  • Noise logs.
  • Temperature logs.
  • Oxygen activation to measure water flow.
  • Communication Testing to check zonal isolation.
• Spontaneous Potential Electro-Kinetic anomalies.
• Borehole spinner.

 1-hour Workshop on leak detection.

Day 2

• Primary Cementing.
• Squeeze Cementing.
• Cement Evaluation Tools. This includes:
  • Basic Cement Bond Log and Variable Density Log.
  • BHGE Family of tools: SBT, INTeX, RAL
  • Ultrasonic Imaging.
  • Isolation Scanner.
  • Through Tubing Cement Evaluation (SCMT)
• Field Examples of cement evaluations.
• Most (90%) of corrosion takes place on the casing outer wall. Cement quality effects on initiation corrosion and on the rate of corrosion.

 1-hour Workshop on Cement Evaluation.

Day 3  

• Corrosion Mechanisms: Various Corrosion Mechanisms
  • Galvanic Corrosion: Includes galvanic, pitting, crevice and uniform corrosion.
  • Chemical Corrosion- this is mainly caused by H2S and CO2 Corrosion.
  • Stress corrosion: the effect of casing stresses on corrosion propagation.
• Multimedia display of the various corrosion mechanisms.
• Outline of the various factors that initiates and propagates the various corrosion mechanisms.
• Corrosion Monitoring
• The physics of the various corrosion Monitoring Tools: This includes-
  • Electromagnetic thickness measurement; this includes the EMT tool of SLB and the Gowell Magnetic Thickness Tool (MTD).
  • UCT: Ultrasonic Casing Thickness imager.
• Flux Leakage Tools.
• Electric Current Leakage tool:
• This covers the Cathodic Protection and Evaluation Tool (CPET)
• Cathodic Protection:
  • Outline of the theory and applications of cathodic protection.
  • Detailed field examples.
• Perforation:
  • Types of explosives; hardware, primary and secondary explosives.
  • Perforation conveyance.
  • Perforations Efficiency.
  • Overbalanced and underbalanced perforations 

1-hour Workshop on Cathodic Protection.

Day 4

• Temperature Logging Tools and their applications under shut-in and flowing conditions.
  • Temperature signatures.
  • Temperature data base application.
  • Signatures in Lost circulation zones.
  • Temperature modelling used to estimate flowrates in oil and water producing zones.
• Permanent Temperature sensors.
• Fibre Optics temperature sensors.
• Theory and applications.
• Field Examples

 1-hour Workshop on temperature profiling.

Day 5

• Uneven Depletion and resulting Crossflow:
  • Causes of uneven depletion.
  • Modelling of uneven depletion.
• Basic Production Logging
• Spinner Calibrations.
• Using 2 chokes to estimate Productivity Index.
• Estimating Productivity index (PI) and reservoir pressure (Pr) for each zone
• Estimating the inter-zone crossflow caused by uneven depletion
• Water and Gas Coning:
  • Basics of water and gas coning.
  • Detection of conning.
  • Coning evaluations and field examples.

 1-hour Workshop on Uneven Depletion and on Coning.