Anadrill -_2_days_stuck_pipe_2nd

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Directional drilling training, part 2

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Anadrill -_2_days_stuck_pipe_2nd

  1. 1. Stuck Pipe Prevention Prentice & Hill, LLC Second Day
  2. 2. Differential Sticking Causes <ul><li>High Differential Pressures </li></ul><ul><ul><ul><li>Excessive Mud Weight </li></ul></ul></ul><ul><ul><ul><li>Drawn Down Formations </li></ul></ul></ul><ul><ul><ul><li>Poor Well Planning </li></ul></ul></ul><ul><li>Well Bore Contact </li></ul><ul><li>Poor Filter Cake </li></ul><ul><li>Little or No Pipe Motion </li></ul>
  3. 3. Solids Induced Pack-off <ul><li>Formation Loose w/ Little or No Bonding </li></ul><ul><li>Insufficient Hydrostatic to Hold Back Formation </li></ul>UNCONSOLIDATED FORMATIONS Causes
  4. 4. Pack-off Due to Unconsolidated Formations Prevention <ul><li>Gel up Mud / Run Hi Vis Sweeps </li></ul><ul><li>Control Drill </li></ul><ul><li>Spot Gel Pill Prior to TOH </li></ul>Plan / Anticipate:
  5. 5. Solids Induced Pack-off <ul><li>Increase Mud Weight, if possible </li></ul><ul><li>Use Under-saturated Water Base Mud </li></ul><ul><li>Pump Fresh Water Sweeps </li></ul><ul><li>Design Casing to Handle Collapse Loads </li></ul>Causes MOBILE / PLASTIC FORMATIONS Formation Extrudes Into Well Bore Due to Overburden Forces. Prevention Proper Well Planning:
  6. 6. Solids Induced Pack-off Causes <ul><li>Control Drill & Ream Connections </li></ul><ul><li>Anticipate Reaming on Trips </li></ul>FRACTURED / FAULTED FORMATIONS Prevention Loose Chunks of Rock Fall into Well Bore Plan / Anticipate
  7. 7. Solids Induced Pack-off Causes <ul><li>Raise Mud Weight, if possible </li></ul><ul><li>Set Casing Appropriately </li></ul>OVER-PRESSURED SHALE COLLAPSE Prevention Shale “Pops” Off Wall Due to Pressure Plan / Anticipate
  8. 8. Solids Induced Pack-off Causes <ul><li>Use Inhibited Mud System </li></ul><ul><li>Minimize Exposure Time </li></ul><ul><li>Be Prepared for “Gumbo Attack” </li></ul>REACTIVE FORMATIONS Prevention Mud Filtrate Reacts Chemically with Formation Plan / Anticipate
  9. 9. Solids Induced Pack-off Causes <ul><li>Increase Annular Velocities </li></ul><ul><li>Better Mud Properties </li></ul><ul><li>Subject of another section </li></ul>POOR HOLE CLEANING Prevention Not Removing Cuttings From Well Bore
  10. 10. Mechanical / Wellbore Geometry Sticking Causes KEYSEATING <ul><li>Minimize Dog Leg Severity </li></ul><ul><li>Case Off Curves Soon After Building </li></ul><ul><li>Use Keyseat Wiper </li></ul><ul><li>Make Frequent Wiper Trips </li></ul><ul><li>Back Ream Out of Hole </li></ul><ul><li>Abrupt Change in Well Bore Path (Dog Leg) </li></ul><ul><li>Long Hole Section Below Dog Leg </li></ul>Prevention
  11. 11. Mechanical / Wellbore Geometry Sticking Causes UNDERGAUGE HOLE <ul><li>Always Gauge Bit & Stabilizers IN and OUT </li></ul><ul><li>Run Gauge Protected Bits & Stabilizers </li></ul><ul><li>Ream Suspected Undergauge Sections </li></ul><ul><li>Undergauge Bit and/or Stabilizers </li></ul><ul><li>Coring (Core heads slightly U.G.) </li></ul>Prevention
  12. 12. Mechanical / Wellbore Geometry Sticking Causes LEDGES & DOGLEGS <ul><li>Run Packed Hole Assemblies </li></ul><ul><li>Ream on Trips Through Problem Zones </li></ul><ul><li>Limber BHAs </li></ul><ul><li>Hard - Soft Interbedded Formation </li></ul>Prevention
  13. 13. Mechanical / Wellbore Geometry Sticking Causes SHOE JOINT BACKS OFF <ul><li>Do Not Overdisplace Cement </li></ul><ul><li>Thread Lock Bottom 3 Joints of Casing </li></ul><ul><li>Drill Out Carefully </li></ul>Prevention
  14. 14. Mechanical / Wellbore Geometry Sticking Causes JUNK <ul><li>Good Housekeeping on Rig Floor </li></ul><ul><li>Keep Hole Covered </li></ul><ul><li>Inspect Equipment Frequently </li></ul>Prevention Something Manmade is Loose in the Hole
  15. 15. Mechanical / Wellbore Geometry Sticking Causes CEMENT BLOCKS <ul><li>Set All Casing As Close To TD As Possible </li></ul><ul><li>Ream Casing Shoe & Open Hole Plugs Before Drilling Ahead </li></ul>Hard Cement Falls In From Casing Shoe or From Open Hole Cement Plug Prevention
  16. 16. Mechanical / Wellbore Geometry Sticking Causes GREEN CEMENT <ul><li>Wash Down Carefully to “Top of Cement” </li></ul><ul><li>Pre-Treat Mud Before Drilling Green Cement </li></ul>Prevention Run BHA Into Un-set Cement
  17. 17. Mechanical / Wellbore Geometry Sticking Causes LINER & SQUEEZE CEMENTING <ul><li>Hazards in Liner Cementing </li></ul><ul><ul><li>Too Much Excess </li></ul></ul><ul><ul><li>Overdisplacement </li></ul></ul><ul><li>Squeeze Cementing </li></ul><ul><ul><li>Hold Pressure on Back Side, If Possible </li></ul></ul><ul><ul><li>Use Cement Retainers </li></ul></ul><ul><ul><li>DO NOT Cement Up a Squeeze Packer (RTTS) </li></ul></ul>Cementing Yourself in the Hole
  18. 18. Trend Analysis <ul><li>Plot Property -vs- Depth or Time and Analyze </li></ul><ul><ul><li>Drag on each Connection </li></ul></ul><ul><ul><li>Torque -vs- Depth </li></ul></ul><ul><ul><li>PWD -vs- Time </li></ul></ul><ul><ul><li>Soap Box </li></ul></ul>
  19. 19. Pressure While Drilling
  20. 20. Pressure While Drilling
  21. 21. Pressure While Drilling
  22. 22. Drag on Trip
  23. 23. Recovery Our Best Preventive Efforts Have FAILED WE’RE STUCK !! What Do We Do Now?
  24. 24. Identifying the Problem: “Why are we stuck?” <ul><li>Stuck Pipe Handbook Flowcharts </li></ul>
  25. 25. Problem Diagnosis <ul><li>Computer Intelligent System on Network at Cambridge Facility </li></ul><ul><li>Charts in Front of Sedco Forex Handbook </li></ul>
  26. 26. Solving the Problem: “What do we do now?” <ul><li>First Actions </li></ul>
  27. 27. Solids Induced Stuck Pipe <ul><li>Stop pumps & bleed pressure to 500 psi </li></ul><ul><li>Hold pressure & cycle drill string up to MUT with no up/down movement </li></ul><ul><li>Try pumping if pressure bleeds off </li></ul><ul><li>Begin working pipe up/down - max 50K overpull </li></ul>Formation Movement / Poor Hole Cleaning First Actions
  28. 28. Solids Induced Stuck Pipe <ul><li>Do not commence jarring </li></ul><ul><li>Increase standpipe pressure to 1500 psi </li></ul><ul><li>Work pipe </li></ul><ul><li>Commence secondary procedures </li></ul>Continued First Actions
  29. 29. Differential Sticking <ul><li>Circulate at maximum allowable rate </li></ul><ul><li>Set compression w/ 50% MUT </li></ul><ul><li>Pull tension w/ 50% MUT </li></ul><ul><li>Secondary Procedures </li></ul>Overbalanced, Filter Cake, Contact Area First Actions
  30. 30. Mechanical Sticking <ul><li>Maintain circulation </li></ul><ul><li>Jar in opposite direction of last movement </li></ul><ul><li>Light loads (50K) w/ systematic increases </li></ul><ul><li>Secondary procedures </li></ul>Dogleg, Keyseat, Junk, Undergauge First Actions
  31. 31. Locating the Problem: “Where are we stuck? <ul><li>Pipe Stretch Measurements </li></ul>
  32. 32. Pipe Stretch Equation L = Length of Free Pipe (ft)  L = Length of Stretch (in)  F = Incremental Force (lbs) W = Weight of Drill Pipe (lb/ft)
  33. 33. Locating the Problem: “Where are we stuck? <ul><li>Pipe Stretch Measurements </li></ul><ul><li>“Free Point” Tool </li></ul><ul><ul><li>Review Stuck Pipe Handbook Procedures </li></ul></ul>
  34. 34. Stuck Here Pull On DP Measure Stretch Here Measure Stretch Here Free Point Tool
  35. 35. Solids Induced Stuck Pipe <ul><li>Jarring </li></ul><ul><li>Back off and wash over </li></ul>Secondary Procedures
  36. 36. Differential Sticking <ul><li>Attack Filter Cake -- Spotting Fluid </li></ul><ul><ul><li>Spot within 4 hrs of sticking </li></ul></ul><ul><ul><li>Omit after 16 hrs </li></ul></ul><ul><ul><li>Rule of Thumb - Soak minimum 20 hrs and a maximum 40 hrs </li></ul></ul>Secondary Procedures
  37. 37. Pipe Releasing Agents Spotting Fluids <ul><li>Pump “shear thinning” spacer </li></ul><ul><li>Viscosity: 100 rpm value > drilling mud </li></ul><ul><li>50 to 100 bbl spacer </li></ul><ul><li>Calculate volume of PRA - Example </li></ul><ul><li>Spot at highest allowable pump rate </li></ul><ul><li>Work pipe (up/down, torque) while soaking </li></ul>
  38. 38. Differential Sticking <ul><li>Reduce Hydrostatic </li></ul><ul><ul><li>Cut Mud Weight </li></ul></ul><ul><ul><li>“U Tube” - Kick it free </li></ul></ul><ul><ul><li>Caution - Well May Come In </li></ul></ul><ul><li>Back Off and Wash Over </li></ul>Secondary Procedures
  39. 39. Mechanical Sticking <ul><li>Jar in opposite direction of last pipe movement </li></ul><ul><li>Back Off and Wash Over </li></ul>Secondary Procedures
  40. 40. Acid Pills <ul><li>Calcium Formations, Strip Filter Cake </li></ul><ul><li>Typically 7.5% to 15% HCl </li></ul><ul><li>Cover stuck zone </li></ul><ul><li>Pump acid quickly to bit </li></ul><ul><li>Large water spacers </li></ul><ul><li>Work pipe while soaking </li></ul><ul><li>Circulate out after 5 minutes </li></ul>Secondary Procedures
  41. 41. Fresh Water Pills <ul><li>Mobile Salt </li></ul><ul><li>Cover stuck zone plus 20 bbl inside drill string </li></ul><ul><li>OBM - Viscous weighted spacer </li></ul><ul><li>Maintain overpull while soaking </li></ul><ul><li>Repeat after 2 hrs </li></ul>Secondary Procedures
  42. 42. Drilling Jars - Benefits <ul><li>Jar stuck pipe immediately </li></ul><ul><li>Minimize fishing / sidetrack potential </li></ul><ul><li>Minimize surface loads (safety) </li></ul><ul><li>Something to do while waiting on tools </li></ul>
  43. 43. Mechanical Jars <ul><li>Most basic type of jar </li></ul><ul><li>Sliding sleeve inside shoulder sleeve </li></ul><ul><li>Holding mechanism locks hammer </li></ul><ul><li>Overpull stretches drill string </li></ul><ul><li>Sudden release when holding mechanism is overcome </li></ul>
  44. 44. Mechanical Jars - Advantages <ul><li>Remain locked until loaded </li></ul><ul><li>More freedom of placement in string </li></ul><ul><li>No special tripping procedures </li></ul><ul><li>Do not jar unexpectedly </li></ul><ul><li>Short jar cycle </li></ul><ul><li>Cost </li></ul><ul><li>Availability </li></ul>
  45. 45. Mechanical Jars - Disadvantages <ul><li>Load may not be varied </li></ul><ul><li>Jarring immediate once load is reached </li></ul><ul><li>Large shock to hoisting equipment </li></ul><ul><li>Rig may not pull over holding force </li></ul><ul><li>Difficult to load in deviated wellbores </li></ul>
  46. 46. Hydraulic Jars <ul><li>Oil reservoir w/ orifice & bypass valve </li></ul><ul><li>Oil bleeds slowly until piston reaches bypass valve </li></ul><ul><li>Hydraulic delay </li></ul>
  47. 47. Hydraulic Jars - Advantages <ul><li>Allows time to set drilling brake </li></ul><ul><li>No torque needed to operate </li></ul><ul><li>Torque does not affect load </li></ul><ul><li>Varied impact force </li></ul><ul><li>Use in deviated holes </li></ul>
  48. 48. Hydraulic Jars - Disadvantages <ul><li>May jar unexpectedly </li></ul><ul><li>Tripping more time consuming </li></ul><ul><li>Longer jar cycle </li></ul><ul><li>More expensive </li></ul><ul><li>Availability </li></ul>
  49. 49. Reasons Jars Fail to Fire <ul><li>Incorrect weight - calculation incorrect </li></ul><ul><li>Pump open force exceeds compression force </li></ul><ul><li>Stuck above jar </li></ul><ul><li>Jar mechanism failed </li></ul><ul><li>Jar not cocked </li></ul><ul><li>Drag too high to load jar </li></ul>
  50. 50. Reasons Jars Fail to Fire (cont.) <ul><li>Jar firing not felt at surface </li></ul><ul><li>Torque trapped in mechanical jar </li></ul><ul><li>No patience </li></ul>
  51. 51. Accelerators - Functions <ul><li>Compensate for short string </li></ul><ul><li>Compensate for hole drag slowing contraction </li></ul><ul><li>Act as a reflector to jar shock wave </li></ul><ul><li>Intensify jar blow </li></ul>
  52. 52. Jar / Accelerator Placement Considerations <ul><li>Sticking point </li></ul><ul><li>Jar direction required </li></ul><ul><li>Differential risk </li></ul><ul><li>Neutral point of tension / compression </li></ul><ul><li>Buckling point </li></ul><ul><li>Drag in the hole section </li></ul><ul><li>Depth of hole section </li></ul>
  53. 53. Placement - Vertical Holes <ul><li>Above buckling point at maximum WOB </li></ul><ul><li>Two DC’s above jars </li></ul><ul><li>No stabilizers above jars </li></ul><ul><li>Accelerators needed in shallow hole sections </li></ul>
  54. 54. Placement - Deviated Holes <ul><li>Do not run jars buckled </li></ul><ul><li>Avoid tension / compression neutral point </li></ul><ul><li>Calculate measured weight reading required </li></ul><ul><li>Account for hole drag </li></ul>
  55. 55. Jar Placement Programs <ul><li>Do not typically account for buckling </li></ul><ul><li>Accurately calculate and account for pump open forces </li></ul><ul><li>Maximize jar impact at stuck point </li></ul><ul><li>Example - Griffith Oil Tools </li></ul>
  56. 56. Fishing - Overshots <ul><li>Catches OD of fish </li></ul><ul><li>Right hand torque operated </li></ul><ul><li>Always run a bumper sub </li></ul><ul><li>Circulating sub </li></ul><ul><li>Basket grapple </li></ul><ul><ul><li>More sturdy, Easier to release </li></ul></ul><ul><li>Spiral grapple </li></ul><ul><ul><li>Stronger hold, Use in slim hole </li></ul></ul><ul><li>Wall hooks </li></ul>
  57. 57. Fishing - Spears <ul><li>Catches ID of pipe </li></ul><ul><li>Consider stop ring </li></ul><ul><li>Risk back off of wash pipe </li></ul><ul><li>Rope spears </li></ul>
  58. 58. Fishing - Taps <ul><li>Use when overshot or spear cannot be used </li></ul><ul><li>Taper Tap - Screws inside fish </li></ul><ul><li>Box Tap - Screws over fish </li></ul><ul><li>Cannot be released & subject to breakage </li></ul><ul><li>String shot cannot be run through taper tap </li></ul><ul><li>Excessive torque will split box tap </li></ul>
  59. 59. Fishing - Junk <ul><li>Magnets </li></ul><ul><li>Junk Baskets </li></ul><ul><li>“Confusion Blocks” </li></ul><ul><li>Mills </li></ul><ul><ul><li>Pilot, Tapered, Concave, Flat-Bottom, Section, Fluted, Watermelon </li></ul></ul>
  60. 60. Fishing - Milling <ul><li>Pilot </li></ul><ul><li>Tapered </li></ul><ul><li>Concave </li></ul><ul><li>Flat-Bottom </li></ul><ul><li>Section </li></ul><ul><li>Fluted </li></ul><ul><li>Watermelon </li></ul>
  61. 61. Washover Operations <ul><li>Run minimum size required - ¼” clearance inside, ½&quot; clearance outside </li></ul><ul><li>Maximum length 600' drill pipe, 300' BHA </li></ul><ul><li>Conditioning trip </li></ul><ul><li>Easy to differentially stick </li></ul><ul><li>Run jars in deeper hole sections </li></ul><ul><li>Steady feed when cutting formation </li></ul><ul><li>“Jerky” feed when going over tool joints </li></ul>
  62. 62. Washover Shoes <ul><li>Short tooth mills (mill tooth) for medium to hard formations </li></ul><ul><li>Long tooth mills for soft formations </li></ul><ul><ul><li>Cut faster </li></ul></ul><ul><ul><li>Hang easier </li></ul></ul><ul><ul><li>Harder to get over top of fish </li></ul></ul><ul><li>Flat bottom for stabilizers, reamers, tool joints, etc. </li></ul>
  63. 63. Solving the Problem: “What do we do now?” <ul><li>THE OTHER OPTION: </li></ul><ul><ul><li>S I D E T R A C K </li></ul></ul><ul><ul><ul><li>Free Point and Back Off as Deep as Possible </li></ul></ul></ul><ul><ul><ul><li>Go Around the Fish </li></ul></ul></ul>
  64. 64. What Do We Do Now? Sidetrack or Fish? <ul><li>It’s Purely a Matter of Economics </li></ul><ul><li>Sidetrack is a good choice when: </li></ul><ul><ul><li>Fish Inexpensive or Recovery Unlikely </li></ul></ul><ul><ul><li>Hole is Cheap (read Fast) to Drill </li></ul></ul><ul><ul><li>Soft Formation - Easy to Kick Off </li></ul></ul><ul><ul><li>Spread Rate (Total Daily Cost) is HIGH </li></ul></ul>

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