PETE 661 Drilling Engineering

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PETE 661Drilling Engineering

• Lesson 24
• Circulation Kill Techniques

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NOTE

• No more Homework!
• The Solution to HW 12 is on the Web
• Our FINAL EXAM will be on Friday, May 2, 1230
  p.m. 230 p.m. Rm. 208
• Equations will be provided, as usual
• You may bring one 8 ½ 11 Eq. Sheet

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Circulation Kill Techniques

• Shut-In Pressures
• Weighting Up the Mud
• Drillers Method
• Wait Weight Method
• Concurrent Method

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Shut-In Pressures

• Once a kick is detected, and proper shut-in
  procedures are followed, the influx will
  continue
• until the fluids in the wellbore are compressed
  sufficiently to where the Shut-in Surface
  Pressure the HSP Formation pressure
  (annulus or DP?)
• No more influx

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Shut-In Pressures

• Once the influx is stopped
• The kick fluids must be removed from the
  wellbore, and
• The low density drilling fluid that was in the
  hole when the kick occurred must be replaced
  with KWM

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U-Tube concept
The Stabilized BHP SIDPP HSPmud_dp SICP
HSPmud_ann HSPkick Formation
Press.
KICK
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Back Pressure Valve in the Drillstring
How do you measure the SIDPP?
Flapper
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Measurement of SIDPP and SICP with Back Pressure
Valve
SIDPP
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Weighting Up the Mud

• Example 5.6
• OWM 13.2 ppg
• MD 10,350
• TVD 10,075
• SIDPP 400 psig
• Estimate the mud weight required to kill the well

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Example 5.6

• KWM OWM SIDPP/(0.052 TVD)
• KWM 13.2 400/(0.052 10,075)
• KWM 13.2 0.76 13.96 14.0 ppg
• This would be considered a 0.8 ppg kick
  (kick intensity)

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Example 5.7
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Example 5.7
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Example 5.7
(3.35 lb/gal)
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Example 5.10
(ok)
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Example 5.10
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Kill Procedures
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KRCP - Kill Rate Circ. Press.- usually fairly
low...

• Lower annulus friction pressure
• Less pressure fluctuation in response to a
  change in choke setting
• Reduced risk of pump breakdown or other
  mechanical problems
• Circulating with larger underbalance pressures
  for the pump liner rating

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KRCP - SPP - KRP

• Reduced instantaneous gas rates through the
  choke manifold and mud-gas separator
• Minimum cuttings throughput at the choke
• Keeping within the capabilities of the
  mud-mixing system
• Normally 1/3 to 1/2 of normal drilling
  circulation rate

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KRP taken

• Every tour by each driller
• When the pumps are repaired or liners changed
• If mud properties are changed
• Every 500 feet of hole drilled
• When the BHA changed
• When bit nozzles are changed

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Well Data
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Well Data
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Well Data
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KRCP (well control)
CDPP (drilling)
Drillstring
Annulus
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ICP KRCP SIDPP
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Driller Method
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Example 5.12
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Example 5.12
( 424.28.34 1,470 )
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Example 5.12
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Circulating Drillpipe Pressure
Drillers Method
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Circulating Drillpipe Pressure
Drillers Method
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(No Transcript)
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Circulating Casing Pressure
(MAASP) Maximum Allowable Annulus Surface
Pressure
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Circulating Casing Pressure
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Circulating Pressure at Casing Seat
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Circulating Pressure at Casing Seat
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• Kick / Mud Mixing
• Kick Migration
• Velocity Profile

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Pit gain while circulating out kick
How might this differ for the Wait and Weight
method?
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Effect of pit gain on casing pressure
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Effect of kick intensity on surface casing
pressure (25 bbl gain)
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Effect of hole size on surface casing pressure
(bbl gain)
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Effect of kick fluids on surface casing pressure
(25 bbl gain)
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WW
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FCP KRP (KWM/OWM)a a 0.75 for turbulent flow
in pipe a 1.0 through bit
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Bit Pressure Drop Increase
Annular Friction
a 1.00 a 0.75
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Circulation Kill Techniques

• Drillers Method
• Wait Weight Method
• Concurrent Method
• Annulus Pressure Profiles
• Kicks in Oil-Based Mud

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Example 5.13
(Final Circulating Pressure)
Make up Table of DPP vs. Strokes
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Example 5.13
Procedure
SICP
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Example 5.13
1,230
1,013
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Example 5.13
WW
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Safety factor added to KWM
(Balanced FCP 1,013 psig)
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Safety factor added to KWM
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Example 5.14
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Example 5.14
SIDPP 1,300 psi
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Example 5.14
SIDPP 1,300 psi KRP 1,100 psi
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Example 5.14
SIDPP 1,300 psi KRP 1,100 psi ICP
2,400 psi
SIDPP 1,300 psi KRP 1,100 psi
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Directional Well
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Concurrent Method
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Kicks in Oil-Based Mud

• Solubility of gas in oil
• reduces surface pit gain measurements
• reduces surface measurements of flow rate
  increase
• reduces SICP
• stays in solution until pressure is reduced to
  bubble point
• as compared to water based mud systems

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Free gas present at the start of circulation
Note effect of gas expansion
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All gas in solution initially (in the Oil Base
Mud)
No gas expansion - initially
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All gas stays in solution throughout circulation
(in the Oil Base Mud)
So, no gas expansion
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Example 5.17
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Example 5.17
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Example 5.17
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Example 5.17
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Example 5.17