drillin with casing
TRANSCRIPT
SPE DISTINGUISHED LECTURER SERIESis funded principally
through a grant of the
SPE FOUNDATION
The Society gratefully acknowledges
those companies that support the program
by allowing their professionals
to participate as Lecturers.
And special thanks to The American Institute of Mining, Metallurgical,
and Petroleum Engineers (AIME) for their contribution to the program.
Drilling with Casing:
What it Can and Can't Do for an AssetWhat it Can and Can't Do for an Asset
Tommy WarrenTommy Warren
Tesco Corp.Tesco Corp.
TulsaTulsa
�� Rotary steerableRotary steerable
�� Fixed cutter bitsFixed cutter bits
�� Shock & vibrationShock & vibration
�� Seismic at the bitSeismic at the bit
�� Drilling with casingDrilling with casing
�� Coiled tubing Coiled tubing
drillingdrilling
10 technologies to invest in this decade
�� StimulationStimulation
�� ProppantsProppants
�� Well tractorsWell tractors
�� ESPESP
DrillingDrilling CompletionCompletion ProductionProduction
From Richard Spears From Richard Spears ––
2005 2005 -- 2006 SPE Distinguished Lecture2006 SPE Distinguished Lecture
What is it?What is it?
How can it help you?How can it help you?
Drilling with Casing - A DEFINITION
Process for simultaneously drilling and Process for simultaneously drilling and
casing a well wherecasing a well where::
�� the well casing is used for the drillstring.the well casing is used for the drillstring.
�� the casing is rotated as needed to drill.the casing is rotated as needed to drill.
�� the casing is cemented in well at TD.the casing is cemented in well at TD.
� Drilling with casing has old roots, but has only recently
become practical because of more robust tools.
� Spindletop discovery well drilled with 10” casing!
� Benefits of casing drilling were understood very early.
� Eliminates drillpipe.
� Reduces trip time.
� Reduces crew size.
� Reduces stuck pipe.
� Reduces overall drilling
time.
� Reduces overall drilling cost.
� Keeps every foot drilled.
� Casing can be set deeper.
� Reduces accidents on rig.
� Requires fewer casing string.
1926 patent – Retrievable & re-runnable casing bit.
Benefits Identified Many Years Ago
First Casing Drilling System
System Defined 35 Years Ago
• Electric Top Drive
• Casing Drive Tool
• Wireline retrievable
• Underreamer
• Casing centralizers
Requirements understood, but the hardware just wasn’t
available!
DownholeSurface
Brown Oil Tool 1971 patentBrown Oil Tool 1971 patent
So what’s different now?
� Top drives - robust & common.
� Casing drive tools available.
� PDC cutters.
� Robust casing connections & accessories.
� Rig automation systems.
� Better drilling fluid systems.
� Downhole tool designs.
� Directional tools.
� Increased economic incentive.� Service company support.
�� NonNon--Retrievable systemRetrievable system–– Simplest and most commonly used type Simplest and most commonly used type
–– String rotation requiredString rotation required
–– No directional trajectory change capabilityNo directional trajectory change capability
�� Retrievable BHA systemRetrievable BHA system–– Motor or casing rotationMotor or casing rotation
–– Multiple runs per sectionMultiple runs per section
–– Directional and straight hole drilling Directional and straight hole drilling
�� Liner drilling systemsLiner drilling systems–– All deep water applicationsAll deep water applications
Casing Drilling Systems Types
• Weatherford DwC® system. Drillshoetm
bits.
• Hughes Christensen EZCasetm drilling shoe.
• Tesco CASING DRILLING® system.
• Operators’ “home grown” systems.
• Many service providers focusing on support.
Casing Drilling Providers
EquipmentEquipment
� Casing handling at surface..
� Protect casing while drilling. .
� Downhole drilling tools..
Oil
Zone
Downhole tools
Casing is the
“Drillstring”
Surface Equipment
Considerations for drilling with casing
Engineering� Well planning
� Operational practices
Handling the Casing
• Protect threads
• Fast connections
• Safe pipe handling
•• Quick rig-up
Casing coupling
Wear Band
Mechanical Casing Protection
Crimping area
TC hardfacing
Thermoplastic centralizers
Courtesy WeatherfordCourtesy Weatherford
Carbide CuttersCarbide Cutters TSP CuttersTSP Cutters
PDC CuttersPDC Cutters
Non-Retrievable Casing Bits
Drilling assembly:
• Locked to casing.
• Extends below casing shoe.
• Capable of multiple runs .
• Often retrieved with braided cable.
• Reliability is critical.
Retrievable System
ProfileNipple
Shoe
Underreamer
Bit
CasingDLA
Motor
Under-reamer
Stabilizers
MWD
RSS
PDC Bit
shoe
Casing
• Directional BHA Can Include Rotary Steerable Tools.
• Can include LWD.
• Wells to horizontal have been drilled.
Retrievable CwD Tools Can Be Used in Complex Wells
Incentive to Drill with Casing
Lost circulation
Stuck Pipe
Kick
Sloughing Shale
Other
24% of time from spud to TD
(Jan 2004 Offshore magazine)
• Faster process.
• Reduces hole conditioning time.
• Reduces trouble time.
• Enables more difficult wells.
00
2020
1010
3030
Tim
e, h
ou
rsT
ime, h
ou
rs
55 1010 1515 202000
Wells in order drilledWells in order drilled
1313--3/8” Surface Casing3/8” Surface Casing
Batch set, drilled ~800 ftBatch set, drilled ~800 ft
Saved 21 days, $1.5 millionSaved 21 days, $1.5 million
BohaiBohai Bay China Bay China –– Faster ProcessFaster Process
Courtesy WeatherfordCourtesy Weatherford
Low pressure thief zone
• Drilled conventionally to 7,400 ft.
• Ran 9-5/8” casing with drillable shoe, conventional float equipment, & crimp-on stabilization.
• Drilled through thief zone @ 20o Inc.
• Cemented while rotating casing.
• Drilled out shoe with rock bit.
• Results• No fluid losses• Maintained inclination• Saved liner and $800,000
Drillable Shoe Reduces Trouble Time
Steel Drillable Shoe
Stabilizer
Courtesy Hughes ChristensenCourtesy Hughes Christensen
• Less fluid loss than with conventional drilling
• Allows lower mud weight
CwD Improves Hole Quality
Mud Weights (ppg)
Casing Drill pipe
9.6 10.2
9.5 10 – 10.3
9.7 10.2 – 10.8
10.1 10.9 – 11.0
CasingCasing DrillpipeDrillpipe
CwD Minimizes Lost Circulation
Spud to Cementing of Intermediate
200 - 300 sack balanced cement plug
7”
Csg.
10 days
CwD
9 5/8”Csg.
4 1/2”Csg.
5 1/2”Liner
7”Csg.
Offset 2
9 5/8”Csg.
3 1/2”Csg.
19 days
5 1/2”Liner
7”
Csg.
Offset 1
9 5/8”Csg.
3 1/2”Csg.
7”Csg.
Offset 3
9 5/8”Csg.
4 1/2”Csg.
0
2000
4000
6000
8000
10000
8 10 12 14 16 18
Equivalent Mud Density, ppg
Measu
red
Dep
th, ft
.Reduces Risks without Needing Liner
Over 130 similar wells drilled in South Texas.
Drilled Conventionally
Casing Drilled
Frac gradient
& trip margin
Pore pressure
& trip margin
4 strings of pipe3 strings of pipe
• 37 wells in 2,000 & 2001 uneconomical
• Sands from 4,000 – 7,000 ft
• Reservoir pressure: 90 to 2,800 psi
• Lost 1000s barrels of mud per well
• 9-5/8” and 7” casing to 7,000 ft
• CwD focus on production enhancement
Increased Production in Depleted Zones
500 psi
300 psi
600 psi
2800 psi
90 psi
2200 psi
� Drilled 57 wells with casing.
� Drilling time cut in half.
� Doubled production rate.
� Doubled ultimate recovery.
Managed Pressure Casing Drilling
Courtesy ConocoPhillips
• Rotating Head + Appropriate gas buster and flare system
Intermixed Pressures in One Interval
T
S5
S3S2
U
12 p
pg
13.5
pp
g
15 p
pg
16.5
pp
g
4000 80006000 10000 12000
Pressure (psi)
12,500
13,000
14,000
14,500
13,500
Measu
red
Dep
th (
ft)
Drilledw/13.5 ppg
Liner
Shell CwD System Used in S. Texas
Shell: WOCWD-0431-05
� UBD of Production Tubing Eliminates at Least One Liner�3-1/2” x 2-7/8” tubing string with disposable bit
� Cost Reduced 30% & Reserves Added
Drl & Trip
Drl with
Casing
S1
S4
� There’s an advantage!
� We now have the capability!
� Are there applications in your assets?
Drilling with Casing Summary
SPE DISTINGUISHED LECTURER SERIESis funded principally
through a grant of the
SPE FOUNDATION
The Society gratefully acknowledges
those companies that support the program
by allowing their professionals
to participate as Lecturers.
And special thanks to The American Institute of Mining, Metallurgical,
and Petroleum Engineers (AIME) for their contribution to the program.