Stuckpipe Prevention & Fishing Operations

Date: TBA | Location: TBA

Course Duration: 5 Days

• Categories of stuck pipe
• The Mechanisms
• Clay Chemistry
• Shale Problems
• Symptoms of shale problems
  • Soft cuttings
  • Clay balls in the flowline
  • Bit and stabiliser balling
  • Tight hole tripping and problems logging
  • Problems increase with time
• Mud Types: use of inhibitors
• Flow rates: Optimum field values
• Pressures
• Effects of hole angle
• Warning signs of inadequate hole cleaning
• Shaker evidence
• Packing off by drill cuttings
• Freeing stuckpipe by drilled cuttings
• Assessment exercise
• ECD
• Control of ECD
• Key seating
• Cement blocks
• Green cement
• Junk
• Ledges and doglegs
• Mobile Formations
• Creep mechanism
• Collapsed casing
• Casing design method across salt sections: uniform and non-uniform loading
• Casing selection across salt sections
• Effects of placement of production packer
• Undergauge hole
• Assessment exercise

Well Bore Stability

• • Earth stresses
  • Current theories of hole fracture
  • Tensile failure mechanism
  • Hole collapse mechanism
  • Effects of hole angle on wellbore stability
  • Effects of azimuth on horizontal well placement
  • Safe mud weights envelope
  • Detailed Exercise

Differential Sticking

• • Differential sticking mechanisms
  • Porosity & permeability effects
  • Factors affecting differential sticking
  • Freeing differentially stuck pipe
  • Pipe freeing agents
  • Reduction of mud hydrostatic pressure
  • Dealing with kicks while freeing stuck pipe
  • The U-tube method
  • Exercises

Decision Trees

• • First actions – Primary freeing methods
  • When stuck by solids or pack off
  • When stuck differentially
  • When stuck other than solids or differential

Back Off Operations

• • Determining free point
  • Stuck Pipe Forces: Calculations
  • Drillstring forces theory
  • Max allowable load
  • Maximum allowable torque
  • Combined loading
  • Free point calculations
  • Back off operations
  • Assessment exercise

Jars And Accelerators – How They Work

• • Mechanical Jars
  • Hydraulic jars
  • Hydro-mechanical jars
  • Fishing jars
  • Accelerators
  • Jar forces
  • Jar envelopes
  • Cocking
  • Firing
  • Placement
  • Fishing Economics
  • Exercise

Fishing Equipment & Operations

• • Review of fish tools
  • Milling tools and assembly
  • Hole cleaning and swarf removal
  • Window milling
  • Milling junk
  • Standard fishing tools

Review

Test (1 ½ hrs)