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Deepwater MPD / PMCD August 21, 2011

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Page 1: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Deepwater MPD / PMCD

August 21, 2011

Page 2: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

• Managed Pressure Drilling (MPD)

– Pressure held on top of riser while drilling.

– Drill in overbalance condition

• Pressurized Mud Cap Drilling (PMCD)

– Pressure of mud column in riser and wellbore plus surface maintained pressure should equal formation pressure at top of carbonates.

– Drill in at balance condition

Page 3: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

MPD Objectives - GSF Explorer

• Prevent gas entering riser.• Improved riser degassing capabilities.• Early kick and loss detection and automated reaction to

these events.• Allows Pressurized Mud Cap Drilling (PMCD) to be

conducted safely.• Ability to quickly manipulate the pressures (up or down)

within the wellbore without the need for mud weight up and circulation.

Page 4: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

• Plan to drill in MPD mode for kick detection for drilling hole section above carbonates.

– Drill overbalanced with RCD bearing installed and maintain surface applied pressure on the well.

– Pressure on welll maintained by circulating through secure manifold choke.

– Improved kick detection

Page 5: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

MPD - PMCD Switch Application

MPD to be used in overbalance mode until the losses in the carbonates become excessive thereafter the system will be changed over to a PMCD (pressurized mud cap drilling) arrangement.

Will use PMCD while drilling carbonates while experiencing severe fluid losses

– Avoid floating mud cap drilling

– Accurate determination of formation pressures

– Maintain well fluid level at surface

Page 6: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

GSF Explorer MPD Equipment Requirements

• Rotating Control Device (RCD)• 21 ¼” 2k Riser Annular BOP• Riser Flow Spool • Drilling Choke Manifold (Secure)• Buffer Manifold• Two Phase Separator• Coriolis flow meter• Drill String Floats - Plunger Type (connections –

stripping in/out)

Page 7: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Approx. 2000 meters of riser between flow

spool and BOP

Page 8: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

General Arrangement MPD Configuration

Page 9: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Secure Manifold – Two Phase Separator

Page 10: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Inline Coriolis Flow Meter

Page 11: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Sequential Operations – MPD to PMCDStart MPD operations with overbalanced fluid

Drill ahead MPD mode encounter carbonates with acceptable losses

Annular

Kill line filled with base oilprior to drilling ahead

Close Annular BOP

Determine reservoir pressure = fracture pressure of carbonates using kill line

Lighten riser fluid till it is just < top fracture pressure

Take significant losses in carbonates

Continue drilling down drill string in PMCD mode with seawater

Kill Line Choke Line

Pump down annulus periodically to keep it gas free (bullhead to the top fracture)

RCD

Pressure mud column below BOP plus kill line hydrostatic

Page 12: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

MPD Operations

GSF Explorer

Ability to stay within a narrow drilling windows (Pore vs. Frac.) .

Mitigate against losses:- early warning and ability to react quickly by decreasing back pressure.

Safe means to drill section :- Increased kick detection sensitivity and reaction.

Back pressure can be used to quicklysupplement drilling fluid density when required if an influx is detected

With MPD maintain CBHP

Page 13: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

PMCD Operations

GSF Explorer

•Annulus mud weight/press < pore pressure.

•Annulus fluid level at surface – casing pressure.

•Pressure monitored at MPD manifold.

•SBM will minimize gas migration as it goes into solution.

•Pump down riser boost with original weight mud

•Pump down drill string with seawater.

Page 14: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Constant Bottom Hole Pressure - Example

Drilling Window

FRACTURE PRESSURE

12.4 ppg

PORE PRESSURE

11.5 ppg

Static Mud Weight

11.5 ppg

Pumps OnAnnular Friction

Loss0.25 ppg

RPM FrictionIncrease0.09 ppg

Surface Back Pressure0.41 ppg

Bottom hole Pressure Stays The

Same

12.25 ppg

Make a Connection riser Boost Pump ON

Stop RPM

Stop Pumps

Page 15: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

MPD & PMCD Carbonate Section

• Drill below the 11-7/8” shoe prior to entering the carbonate section. To be drilled in MPD Mode.

• Carbonates are anticipated to be vugular and/or fractured and may lead to severe/total losses with no returns.

• Depending on the loss rate > 20% PMCD will commence.

• There may be further losses as the pore pressure decreases (in PMCD mode) as the carbonates are drilled deeper.

Page 16: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

4300m brt

Shale

Silt/Sand

Carbonate

Sand / Shale /Coal

Choke Line

Riser Boost Line

Kill Line

MPD Drilling into Carbonates

losses> 20%Close in (annular BOP) open kill

line to base oil and record pressure

Kill line Pressure

Drilling in MPD mode

Kill line pre-filled with treated

base fluid

Kill line pressure to balance pore

pressure in carbonates

Carbonate section below 11 7/8”shoe

Potential for gas in Carbonate section in

the Fractures &

Vugs

Page 17: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

4300m brt

Shale

Silt/Sand

Carbonate

Sand / Shale /Coal

Choke Line

Riser Boost Line

Kill Line

150100 200

50 250

300

150100 200

50 250

300

Calculate lighter mud in riser to give +/- 300 - 500 psi surface

annular back pressure displace into well

Light mud to Riser

annulus via boost.

Pump seawater down string establish stable injectivity at

drilling rate

4300m brt

Shale

Silt/Sand

Carbonate

Sand / Shale /Coal

Choke Line

Riser Boost Line

Kill Line

150100 200

50 250

300

150100 200

50 250

300

Annulus Pressure at MPD Choke

Kill Line Pressure

Page 18: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Drill ahead w/seawater down string, Bullhead +/- 20bbls original weight

mud down riser boost annulus every hour.

Seawater carries

cuttings into loss zone

Periodic pumping to

annulus maintains it hydrocarbon free – pump in at BOP

4300m brt

Shale

Silt/Sand

Carbonate

Sand / Shale /Coal

Choke Line

Riser Boost Line

Kill Line

150100 200

50 250

300

150100 200

50 250

300

Annulus Pressure at MPD Choke

Drill ahead w/ seawater, further loss zone encountered. Shut in and assess

pressures using kill line.

Possibility of X flow

between loss zones

Drop in surface annular

pressureLighter Riser mud stays in

the riser annulus

New loss zone at lower

pressure

Monitor Surface annular

pressure

Page 19: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

PMCD

• During PMCD the pore pressure may start to decrease this will be noticed by a drop in surface annular pressure.

• Shut in well on upper BOP annular & open annulus again to base fluid in the kill line & recalculate new pore pressure.

• Evaluate whether to change out the riser to lighter mud or to pump more lighter mud below BOP.

Page 20: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

Drill ahead PCWD Cuttings plugging off loss zone. Pressure increase in

annulus & DP

Indications an increase in Pump

pressure and annular pressure

Cuttings plugging off the loss zone/s

Control OptionsDepending on pressures involved:•Increase pressure to induce losses•Revert to MPD drilling

Page 21: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above

PMCD

• Should the pump pressure and the surface annular pressure rise together, this is indicative of the loss zone starting to heal over.

• Depending on the pressures seen.

– Induce further fractures and continue in PMCD mode

– Return to MPD mode.

Page 22: Deepwater MPD / PMCD - My-Spreadmy-spread.com/files//2916/TLM - Pres MPD-PMCD Supt Meeting Aug… · • Plan to drill in MPD mode for kick detection for drilling hole section above