PETE 625 Well Control

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PETE 625Well Control

• Lesson 20
• Snubbing and Stripping,
• Blowouts,
• and Casing Seat Selection

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Chapters 9, 10 and 11

• Snubbing and Stripping - Ch. 9
• Blowouts - Ch.10
• Casing Seat Selection - Ch.11
• Kick Tolerance

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Assignments

• HW 11 Ch 6, Problems 1, 3, 5,
  11 and 19 
•            Due Friday, July 16
• Read Chapters 9, 10 and 11

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Schedule

• Project Abstracts are due on Friday, July
  16. Type-written, less than one page. 
  Drilling topic.
• Project Presentations Monday, July 19
• FINAL Wednesday, July 21, 9-11 a.m. in
  Room 511

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Ar
ph
Fs snub force
Np number of active cylinders
Ac
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• Liquid lubricates
• better than gas
• Avoid hydrate formation

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Dampening chamber extends the life of the packing
element
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• Pipe weight
• Pressure forces
• Mechanical friction
• Fluid drag
• Snubbing force

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Blowout Control (Ch. 10)

• Put out the fire, if any
• Clean up around wellhead or, remove wellhead
  if damaged
• Cap the well
• Get well pressures under control
• Drill relief well if necessary

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150 gal/min 8,500 12,000 psi
Gelled water/sand slurry
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• Lower assembly
• over blowing well
• Attach bottom
• flange
• Connect lines
• Open side valve
• Close top valve

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4
2
Seals energized Slips set
1
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Steel balls followed by String rubber
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• Position uncertainties
• Along the wellbore
• Lateral to the
• wellbore
• Perpendicular to the
• wellbore

Ellipsoid of uncertainty
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An electromagnetic tool can detect pipe
200 ft away
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Possible Momentum Kill
Diverter hookup
Kill string
If sonic speed is achieved pwh pe
If flow is subsonic pwh pe
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Dynamic Kill
Higher circulation rates increase friction and
hydrostatic head
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The dead string permits monitoring of dynamic BHP
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Casing Seat Selection (Ch.11)

• Keep mud pressures between the pore pressure and
  the fracture pressure everywhere within the
  openhole interval
• Maintain Trip and Kick Margins
• Consider Kick Tolerance

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Fracture Gradient
Pore Pressure Gradient
Well Depth, ft
Well Depth, ft
Fracture Pressure
Pore Pressure
Mud Weight Equivalent, lb/gal
Pressure, psig
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Fracture Gradient
13 3/8
Pore Pressure Gradient
Min. MW
Well Depth, ft
Well Depth, ft
Max. MW
9 5/8
7
4 1/2
Mud Weight Equivalent, lb/gal
Mud Weight Equivalent, lb/gal
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Pore Pressure
Pore Pressure
Fracture Pressure
Fracture Pressure
Mud Pressure
Mud Pressure
Well Depth, ft
gm 0.648 psi/ft
hK 1,000 ft
hK 500 ft
hK 0 ft
gK 0.1 psi/ft
Pressure, psig
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gm 0.523 psi/ft
gK 0.1 psi/ft
gm 0.648 psi/ft
gK 0.5 psi/ft
gK 0.1 psi/ft
gK 0.1 psi/ft
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If hK2 hK1
then pcs2 pcs1
pcs1
pcs2
hK2
hK1
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Kick Tolerance

• Book Definition

• Note that this definition does not specifically
  account for the effect of Kick Size

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Kick Tolerance
Kick Tolerance, lb/gal
0
Kick Size, bbl
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Kick Tolerance
After Large Kick and Stabilization
Casing Seat at 2,500 ft
After Small Kick and Stabilization
Depth, ft
Before Kick
Kick at 10,000 ft
DP
Wellbore Pressure, psi
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