Warren

(1)

SPE DISTINGUISHED LECTURER SERIES

is 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.

(2)

Drilling with Casing:

What it Can and Can't Do for an Asset

Tommy Warren

Tesco Corp.

Tulsa

(3)

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

drilling

10 technologies to invest in this decade

StimulationStimulation

ProppantsProppants

Well tractorsWell tractors

ESPESP

Drilling

Drilling CompletionCompletion Production_Production

From Richard Spears

–

2005

-

2006 SPE Distinguished Lecture

What is it?

How can it help you?

(4)

Drilling with Casing - A DEFINITION

Process for simultaneously drilling and

casing 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.}

(5)

_{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.

(6)

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!

Downhole Surface

Brown Oil Tool 1971 patent

(7)

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.

(8)

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

(9)

• Weatherford DwC® system. Drillshoetm bits. • Hughes Christensen EZCasetm _{drilling shoe.} • Tesco CASING DRILLING® _system.

• Operators’ “home grown” systems.

• Many service providers focusing on support.

(10)

Equipment

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

(11)

Handling the Casing

• Protect threads

• Fast connections

• Safe pipe handling

•

(12)

Casing coupling

Wear Band

Mechanical Casing Protection

Crimping area

TC hardfacing

Thermoplastic centralizers

(13)

Courtesy Weatherford

Carbide Cutters

Carbide Cutters _{TSP Cutters}_{TSP Cutters}

PDC Cutters

(14)

Drilling assembly:

• Locked to casing.

• Extends below casing shoe.

• Capable of multiple runs .

• Often retrieved with braided cable. • Reliability is critical.

Retrievable

System

Profile Nipple Shoe Under reamer Bit Casing DLA

(15)

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

(16)

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.

(17)

0 0 20 20 10 10 30 30 T im e , h o u rs T im e , h o u rs 5 5 1010 1515 2020 0 0

Wells in order drilled

13

13--3/8” Surface Casing3/8” Surface Casing Batch set, drilled ~800 ft

Batch set, drilled ~800 ft

Saved 21 days, $1.5 million

Bohai

Bay China

–

Faster Process

Courtesy Weatherford

(18)

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 Christensen

(19)

• 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

Casing

(20)

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.

(21)

0 2000 4000 6000 8000 10000 8 10 12 14 16 18

Equivalent Mud Density, ppg

M e a s u re d D e p 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

(22)

• 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.

(23)

Managed Pressure Casing Drilling

Courtesy ConocoPhillips

(24)

Intermixed Pressures in One Interval T S5 S3 S2 U 1₂ p p g 1₃ .5 p p g 1₅ p p g 1₆ .5 p p g 4000 6000 8000 10000 12000 Pressure (psi) 12,500 13,000 14,000 14,500 13,500 M e a s u re d D e p th ( ft ) Drilled w/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

(25)

There’s an advantage!

We now have the capability!

Are there applications in your assets?

(26)