Well Intervention: Completion and Control Equipment

Introduction

• Instructor: Ahmed (Mechanical Engineer, graduated 1983, oil field industry since then)
• Experience: C-tubing, wireline, well testing, specialized in coil tubing and stimulation
• Teaching: Well intervention courses since 1995 in 18-19 countries
• Course Level: Basic well intervention for young engineers

Previous Sessions Recap

• Completion Operations: Well control, pressure control equipment, hydrates, killing the well
• Last Session: Introduction to completions, accessories, and tubing selection criteria (diameter, strength, resistance)
• Current Topic: Completion tubing movement and accessories

Key Question: Why Do Tubing Strings Move Up and Down?

• Answer: Due to temperature effects (metal expansion and contraction)
• Solution: Use of accessories that absorb fluctuations in tubing length

Accessories for Tubing Length Fluctuations

• Types:
  • Polish bore receptacle (PBR)
  • Tubing seal assembly
  • Extra-long tubing receptacle (ELTR)
  • Expansion devices
• Flow Coupling vs. Blast Joint:
  • Blast Joint: Protects tubing from external erosion, thicker walls
  • Flow Coupling: Placed below/above accessories to withstand internal erosion

Landing Nipples and Safety Valves

• Landing Nipples: Designed for downhole safety valves (DHSV)
• Types of Safety Valves:
  • Obsolete:
    • Pressure-activated (ambient, differential pressure types)
  • Current: Surface control subsurface valves (SC-SSV)
    • Wireline retrievable (piston, spring, flow tube, flapper mechanism)
    • Tubing retrievable (full bore, larger ID, used for high pressure/low pressure wells)

Operational Principles and Practical Considerations

• Running Wireline Safety Valve:
  • Have to be run open due to pressure issues (use of prong to keep flapper open)
  • Fluid for pressure systems: Compatible with location supply
• Opening/Closing Mechanism:
  • Use of hydraulic pressure to control piston/spring system
  • Importance of equalizing pressure before opening any device

Side Pocket Mandrel (SPM)

• Purpose: Used for gas lift in artificially lifted wells
• Placement: Accurate depth measurements crucial for function
• Other Valves:
  • Dummy valve
  • Chemical injection valve
  • Circulation valve
  • Differential kill valve

Sliding Side Door (SSD)

• Purpose: Allow communication/circulation between tubing and annulus
• Key Facts:
  • Used for communication/circulation
  • Equalize pressure before opening
  • Ensure full opening to prevent seal damage
  • Placement: One joint above packer or between two packers
  • Standardization of opening mechanism (all jar up or all jar down)

Packers

• Types:
  • Permanent
    • Set hydraulically/electrically
    • Integral part of casing, retrievable only by milling
  • Retrievable
    • Set hydraulically/mechanically
    • Can be reset and reused
• Decision Factors: Use permanent for high pressure/temperature wells; retrievable for frequent changes

Tubing Seal Assembly

• Tubing Seal Assembly (TSA): Placed at varying depths depending on well type (injector, production, high-temperature)
• Scenarios of Leaks:
  • Permanent packer leak: Kill the well, perform well intervention
  • TSA leak: Use wireline to place a plug in landing nipple

Wireline Entry Guide

• Purpose: Provides easy access for wireline tools to return from open hole to tubing assembly
• Types: Mule shoe, bell type (each with specific advantages)

Final Points

• Completion: Overview completed; complexities of completion systems
• Course Continuation: Next session on Wireline operations

Q&A Session Highlights

• Importance of accurate depth and equalization
• Different use cases for various safety valves and completion tools
• Techniques for setting/retrieving packers
• Practical advice on preventing leaks and managing well integrity