CASING DRILLING™ REVIEW CASING DRILLING™ REVIEW

FORFOR

ASIA PACIFIC BUSINESS UNITASIA PACIFIC BUSINESS UNIT

By Andrew By Andrew Harris Harris –– Manager, CASING Manager, CASING DRILLINGDRILLING™™

Email: Email: andrew_harris@tescocorp.comandrew_harris@tescocorp.com

WE SEE DRILLING

CASING DRILLING® Candidate SelectionWells where tophole sections are controlled drilled for hole cleaning

Wells with Borehole Stability ProblemsWells with Borehole Stability Problems

Wells with significant Lost Circulation

Wells where CASING DRILLING® can eliminate a casing string

CASING DRILLING® can provide significant time savings in areas where high rigCASING DRILLING  can provide significant time savings in areas where high rig 

rates apply 

Utilising a small rig – Single mast, small pumps, Limited Horsepower

CASING DRILLING® Benefits: Wellbore Strengthening

Significant reduction in lost fluids when Drilling with Casing due to “Plastering Effect” (continuouslyPlastering Effect  (continuously trowelling of the wellbore wall by the couplings)

Filter Cake is plastered into the wallFilter Cake is plastered into the wall and is not scraped off by bit trips or tool joint impacts

Cuttings are ground up finer and lessCuttings are ground up finer and less cuttings are returned to surface 

Instead they are plastered into the wall, strengthening the wellborewall, strengthening the wellbore

Reduced Losses and Improved borehole stability

TESCO Casing Drilling® Systems

D ill L k

Casing StringMOTOR BHA ROTARY STEERABLE BHA

Casing Profile Nipple

Drill Lock AssemblyNon Retrievable –

Drillable Casing ShoeLevel 2 system+ No rig modification, very easy to implement+ Can drill out for Directional Retrievable BHA’s –

Casing Shoe

Internal Stabilizers

+ Can drill out for subsequent casing strings- Vertical holes only and 1 bit / hole section

Directional Retrievable BHA s Level 3 & 4+ Allows for multiple bit/bha changes+ Allows directional control, LWD+ No Rig Modifications Required- Requires up-front Eng. / planning.

Under‐ Reamer

PD Motor

Float Collar

Casing String

MWD

MWD / LWD

Roller ReamerTesco XCD™ PDC 

diamond enhanced CASING DRILLING®

BitUG

Non‐Mag Drill Collar

Float Sub

Rotary Steerable

MWD / LWD

designed to drill soft to 

medium‐soft formations 

at high rates of 

UG Stabilizer

Pilot Bit

Rotary Steerablepenetration

12,000 psi UCS

D‐exp >1.0

CASING DRILLING™ Global Experience

OVER 3.2 MILLION FEET DRILLED WITH CASING

Casing drilled with 

Subsea Casing Drilled with Motor BHA

31

4

ll d h l h

Directional Casing Drilling

Rotary Steerable Tools 

7

104

Drilled with retrievable assembly

Drilled while Coring with Casing

629

7

Drilled with disposable bit

Drilled with drillable shoe

330

144

ComplexityUpdated 10/31/2010

CASING DRILLING™ APBU 2007 ‐ 2010

• Total 26 CD wells • 23 x 13 3/8” / 3 x 9 5/8”• 9 Level II   • 17 Level III’s l (f ) l (f ) l17 Level III s• 25 Offshore / 1 Onshore

ll l ’

Level II (ft) Level III (ft) Total Ftg.

7,619 40,077 47,773

• All Level 3 using Motor Assy’s• LWD – Gamma / Res / PWD• 9 Wells were Dir. From Platforms• Inclinations 20° to 76°• 3 Wells, used Gyro Mwd for collision avoidance• 4 Wells from Semi‐Submersible• 4 Wells from Semi‐Submersible

CASE HISTORIES

Malaysia

CASING DRILLING® Implementation

Objectives for implementing retrievable CASING DRILLING™ :

1. Improve the safety and efficiency of casing running and handling with a stabber less casing drive system (CDS™);

2. Prove the concept of batch CASING DRILLING™ commercially and technically;

3 To enable CASING DRILLING™ to become the base case for drilling top hole3. To enable CASING DRILLING™ to become the base case for drilling top hole sections;

4. Prove the directional capability of 13 3/8‐in. CASING DRILLING™ assemblies;

5. Minimize flat times associated with conditioning and cleaning the hole in soft unconsolidated directional top hole sections in the field;

6 Improve the drilling performance in the top hole formations though superior hole6. Improve the drilling performance in the top hole formations though superior hole cleaning with 13 3/8‐in. casing versus 5 1/2‐in. drill pipe;

7. Log the section with gamma, resistivity and annular pressure while CASING DRILLING™ ;DRILLING™ ;

8. Casing drill from the conductor shoe to section TD in one run.

Success Offshore BruneiOperator: Shell Brunei Petroleum (BSP)Rig: BIMA (Jack‐Up)Casing Size: 13‐3/8 – 72lbs/ft, L80, VAM TOPCasing Size: 13 3/8  72lbs/ft, L80, VAM TOP

Drilled to the MWD flowrate maximum of 800gpm 

Operations:

Drilled 580m, average penetration rate of 120m.hr (390ft.hr)No hole cleaning issues.  Torque and Drags trendedDrilled with Seawater, pump Hi‐Vis pills every jointDrilled with Seawater, pump Hi Vis pills every joint

Highlights:No QHSE incidents occurred implementing a “New Technology”No rig modification are required, just make up TESCO CDS™ to TDSFaster on‐bottom ROP CASING DRILLING™ vs Conventional drillingSuccessfully hung Casing in the wellhead and cementedO D ill d it’ C d th M t bl i t i d b k thOnce Drilled it’s Cased, the Motor assembly is tripped back thru the casing at TD

©2010 TESCO Corporation

Performance CASING DRILLING™ –Batch Drilled Surface Intervals

1st WELL

BHA: Mud Motor w/1.5º bend / LWD (gamma/res./ pwd) & Gyro‐MWD

Drilled to TD at 1005m ‐ 815m @ 82m/hr avg on Btm ROP

Built angle from 8.4º to 37.9º 

Lost Circulation, switched to seawater to complete section

2nd WELL

BHA: Mud Motor w/1.5º bend / LWD (gamma / res./pwd)

Drilled to TD at 1201m ‐ 1001m @ 100m/hr avg.on Btm ROP

B ilt l f 11º t 58ºBuilt angle from 11º to 58º 

Good FIT prior to drilling 12‐1/4” section. 

CASING DRILLING Saved 6.41days / 3 wells

©2010 TESCO Corporation OTC 20880

Subsea CASING DRILLING™ ImplementationExploration Well - Offshore Sarawak

CHALLENGE

Subsea  Exploration well from Semi‐Submersible 

Water Depth of 340’

Regulations – Have to drill 8‐1/2” pilot hole for Shallow Gas

Require LWD Logs over section

Seismic shows no anomalies, low risk of Shallow GasSeismic shows no anomalies, low risk of Shallow Gas

SOLUTION

Implement TESCO CASING DRILLING® Technology

1st Well Drilled to TD – 2,191ft in 3.6 bit hrs @ 608ft/hr avg

2nd Well Drilled to TD – 2,281ft in 4.7 bit hrs @ 485ft/hr avg

3rd Well Drilled to TD – 2,330ft in 4.3 bit hrs@ 543ft/hr avg3 Well Drilled to TD  2,330ft in 4.3 bit hrs @ 543ft/hr avg

Eliminate the 8‐1/2” pilot hole

Superior hole cleaning than Conventional drilling

Faster on bottom ROP than Conventional drillingFaster on‐bottom ROP than Conventional drilling

CASING DRILLING Saved 1.25 days over Conventional Well©2010 TESCO Corporation

Subsea CASING DRILLING™ ImplementationExploration Well – West Malaysia

CHALLENGE

Subsea Exploration well from Semi‐Submersible       in 55m water with subsea BOP stack

Require LWD Logs over section

Fault predicted at 950m, potential losses or pressure connectivityp y

SOLUTIONUse retrievable CD‐BHA ‐MWD/ LWD / Motor assembly to drill 13‐3/8” Casing from 20” shoe to TD at 1100m

Drilled to TD at 1100m – 650m in 13hrs @ 50m/hr Bt ROPavg. on Btm ROP

Reduce risk of hole problems associated with losses 

Reduce risk of hole problems associated with    borehole instabilitborehole instability

©2010 TESCO Corporation OTC 20880

OBSERVATIONS ANDOBSERVATIONS AND LESSONS LEARNT APBU

Tophole CASING DRILLING™ p

”0

200

DEPTH VS ANNULAR VELOCITY CASING DRILLING™ vs 5 ½” DP

Velocity @ 700gpm

Velocity @ 1100gpm

13-3/8" Casing in 26" Conductor Comparison of Annular

Velocities” ” h l

200

400

5.5" DP in 26" 5 ½” DP x 17 ½” hole

vs13 3/8” Casing x 17 ½” hole

Conventional DP

600

epth

, m

trs

13-3/8" Casing in 17-1/2" Openhole

5-1/2" Drillpipe in

17-1/2" Openhole

Conventional DPLimit ROP to ~60m/hr

CASING DRILLING™ • Superior Hole Cleaning

800

1000

De m • Superior Hole Cleaning

• Faster Penetration Rates

1000

1200 BUSINESS CASE FOR CASING DRILLING™

14000 10 20 30 40 50 60 70 80 90 100

Annular Velocity m/min

8" BHA in CASING DRILLING™

MALAYSIA

Lessons Learnt Lessons Learnt –– APBU APBU CASING DRILLING™CASING DRILLING™Well PlanningWell Planning

Single point of contact from concept through to implementation

Project Management – TESCO LEADS!‐We understand the SYSTEM and interfaces

Detailed Risk Assessments 

Detailed CASING DRILLING™ programs 

(Eng./ Equip. / Procedures / Contingencies / Well Control)

Alignment with DD company as to directional / logging objectives and drilling performance

Lessons Learnt APBULessons Learnt APBU13 3/8”Directional CASING DRILLING™ 13 3/8”Directional CASING DRILLING™ 

Motor with a 1.5° bend and Milltooth bit capable of >6°/30m DLS (100% slide)

Motor with a 1.5º bend and PDC bit capable of 3.5º/30m DLS (100% Slide)

Mitigate against high dogleg severities – recommend a 1.15° bend on motor

CASING DRILLING™ w/ motor assy –dropping tendencies in soft formations

Steady toolfaces while sliding, no hanging up in either well from 36° to 58° with 13 3/8” Casing  

First implementation of Gyro‐MWD in CASING DRILLING™ system for surveys / collision avoidance – no issues.

No issues running LWD – Real‐time Gamma / Resistivity / Pressure While Drillingg / y / g

Trending Torques &Drags while CASING DRILLING™ is essential for success. 

CASING DRILLING™ with mud – No issues with detection from MWDCASING DRILLING  with mud  No issues with detection from MWD

CASING DRILLING™ with seawater – Detection issues surveys / real‐time data

Directional Performance 13 3/8” CASING DRILLING™

Wellplan • Planned DLS is 2.5°/30mB ild I f 8 43° t 60°

100% slide : 2.0 – 5.8°/30m at the start of section • 80 slide /20 Rot : 4.5 – 5°/30m• In Rotary – Assy dropping ‐0.9°/30m • Total ratio for Slide / Rotary  : 49% / 51%• Build Inc. from 8.43° to 60°

• Turn Azi from 125° to 115° then left to 126°

/ y /• Avg ROP rotating : 120 – 180 m/hr• Avg Rop Sliding : 80 – 100m/hr

Cuttings‐ CASING DRILLING™  Seawater Tophole West MalaysiaSeawater / Hi‐Vis sweeps

CASING DRILLING™ Tophole with Motor CD‐CASING DRILLING  Tophole with Motor CDBHA c/w 1.5º bendSeawater c/w 20bbl Hi‐Vis sweeps every joint, Claystone formationj , yDirectional CASING DRILLING™ at +400m/hr (Inst)

Tophole 13 3/8” CASING DRILLING™East Malaysia ‐ Seawater 

Block height

FAST !!

CASING DRILLING™ Tophole with Motor CD‐BHA c/w 1.5º bendS t / 20bbl Hi ViSeawater c/w 20bbl Hi‐Vis sweeps every joint, sandstone formationDirectional CASING DRILLING™ at +1400ft hr+1400ft.hr

Cuttings‐ CASING DRILLING™  KCL‐PHPA MUDTophole West Malaysiap y

KCL‐PHPA Mud

• Mud System – Inhibits reaction with clays

• Cuttings are removed – even sliding

• At higher ROP’s difficult to remove solids

• Mud Wt increases while drilling – ECD’s

• Observe higher break over torque at conns• Observe higher break‐over torque at conns.

• Spend time Circulating hole clean

MWD Detection Top hole CASING DRILLING™Experience in APBU using SeawaterTop hole CASING DRILLING™ with a Mud System – No issues with Survey / real‐time LWD detection

MWD Systems are primarily setup for drilling with mud system

13 3/8” Casing Drilling with Seawater – less viscous fluid13 3/8  Casing Drilling with Seawater  less viscous fluid 

Issues with detection ‐ Cavitation / turbulent flow / Noise / Attenuation of signal/ Smaller Signal)

Company A

S l i R d d d l 0 12 S P lSolution ‐ Reduced modulator gap to 0.12mm – Stronger Pulse

Set Frequency of 16Hz at 3BPS – Decodable signal while drilling / surveying

Company B

Signal attenuates going from BHA ID to larger Casing ID (therefore better for smaller casing sizes)

Changed MWD pulser ‐ slower bigger pulse 

Frequency 0.5Hz at 3bps worked for detection with seawater (D&I surveys only)q y p ( y y)

However the above is not Compatible with Gwd

Implemented EM Tools (Electro‐Magnetic pulse MWD) in‐combination with mud‐pulse tools successful.

Lessons Learnt APBU Lessons Learnt APBU 

Presently not using Centralization on the Casing  

Decision taken to perform ‘Poor‐boy’ cement job

Cementing Issues 

p y j

Under‐displace cement, drop the top plug only

Typically hold pressure for 5.5hrs – ok

Pumped 50% excess‐ No returns to surface due to over‐gauge hole

Increase to 75% excess

CBL – yielded good cement

Surface Wellhead Issues PDDP

Keep the Wellhead hanger assembly loose 

Faster method of installation with the CDS™

Surface Wellhead Issues    PDDPQ1, 2011 

After release BHA with PDRT, pick up hanger and Land – no wiper trip

Lessons Learnt Lessons Learnt APBU APBU –– Shallow SS Wells Shallow SS Wells 

Semi‐Submersible Rigs

Alignment – ballast control needs to keep “double bubble”

b b k l hCan be an issue, best practice keep a slope indicator in Doghouse

Water Depth – Currently only using in Shallow Water depths – 350ft

At TD require to POH with Casing to space out to run CHRT or Wellhead hangerAt TD, require to POH with Casing, to space out to run CHRT or Wellhead hanger

Can Casing Drill Riser‐less or with SSBOP stack installed in shallow water

13 3/8” x 16” thru potential Shallow gas, higher ECD’s than 8 ½” hole pilot hole

Conclusion ‐ Highlights in APBU

No accidents or injuries from CASING DRILLING™ after 47,773ft

Footage ft

25,000

30,000Level II (ft) 

Level III (ft) 

TESCO DOWNHOLE TOOL RELIABILITY – 100%!!!! 

Track Record in APBU with Global relevance 10,000

15,000

20,000 Total Ftg 

Some 1st in CASING DRILLING™ operations

Di ti ll D illi 13 3/8” C i t i li ti f 58º 76º

0

5,000

2007 2008 2009 2010

Directionally Drilling 13 3/8” Casing to inclinations of 58º ‐ 76º

Drilling with Retrievable CASING DRILLING™ system from a Semi‐Submersibles (Subsea)

Successfully deployed Gyro Mwd in BHA for tophole Anti collisionSuccessfully deployed Gyro Mwd in BHA for tophole Anti‐collision

Gamma Logged thru 9 5/8” Casing in PNG – No attenuation of the Signal

Proved up Performance CASING DRILLING™ tophole formations with SeawaterProved up Performance CASING DRILLING  tophole formations with Seawater

Inst. ROP’s of +1600ft.hr (+500m/hr), Average ROP’s of  390ft.hr (120m/hr)