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Brulpadda – Game Changer?

Stephen R Clark1, Johannes L van Niekerk2, Jim Petrie3

1 Solar Thermal Energy Research Group (STERG), Dept. Mechanical and Mechatronic Engineering, Stellenbosch University, South Africa; +27 (0)21 808 4016; sclark@sun.ac.za

2Solar Thermal Energy Research Group (STERG), Dept. Mechanical and Mechatronic Engineering, Stellenbosch University, South Africawikus@sun.ac.za

3 School of Chemical and Bio-molecular Engineering, University of Sydney.

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• BS Mechanical Engineering – UC Berkeley 1976

• MS Petroleum Engineering – Stanford 1977

• International Oil and Gas Development 1977 - 2016• USA – Texas, Louisiana• Europe – UK, Norway• South America – Argentina, Venezuela• Asia – China• Africa – Ivory Coast, Ghana, Nigeria, Cameroon, Angola, Mozambique

• Oil / Gas Royalty owner - Texas

• Currently studying at Stellenbosch University for a PhD

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• “South Africa could be days away from a massive new deepsea energy find” – Business Insider,

29 January 2019

• “Potential game - changer for SA as Total strikes big gas deposit off Southern Cape” – BizNews , 7 February 2019

• “New oil find could be a 'game changer' for SA, says Ramaphosa ” - Fin24

• “Brulpadda delivers the goods for Total” –WoodMacKenzie

• “Total announced Thursday that it has made a “significant” gas condensate discovery on the Brulpadda prospect,” Rigzone

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• Prospect

• Size

• Development

• Conclusion

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8Source : Total

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• 2001 –Ranger / CNR acquired exploration rights to block 11B / 12B

• 2001 – 3700 km 2D seismic

• 2004 – Paddavisie ‘play’ developed with PASA

• 2013 – Total purchases 50% interest and takes operatorship

• 2014 – Attempt to drill Brulpadda 1X

• 2018 – Qatar Petroleum buys 25% interest, Africa Energy 10%*

• 2018 / 2019 – Return with new rig and drilled well

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Kitchen, Trap and Seal• Hydrocarbon Kitchen - An area of the subsurface where source rock has reached

appropriate conditions of pressure and temperature to generate hydrocarbons; also known as source kitchen, oil kitchen or gas kitchen.

• Trap - A configuration of rocks suitable for containing hydrocarbons and sealed by a relatively impermeable formation through which hydrocarbons will not migrate. Traps are described as structural traps (in deformed strata such as folds and faults) or stratigraphic traps (in areas where rock types change, such as unconformities, pinch-outs and reefs).

• Seal - A relatively impermeable rock, commonly shale, anhydrite or salt, that forms a barrier or cap above and around reservoir rock such that fluids cannot migrate beyond the reservoir.

Source – Schlumberger Glossary

11Source : PASA

12Source : Total

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Source : Africa Energy, Pareto Securities Conference, Sept. 2018

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Source : Mudaly, K.;Turner, J.; etal 2009 Source : Africa Energy

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Volumetrics provide a static measure of oil or gas in place. • Net Thickness - t• Areal Extent – l * w• Porosity - φ• Hydrocarbon Saturations - Sg, So• Water Saturation – Swi• Formation Volume Factor – Bg, Bo

For gas – “G = (t*l*w* φ)*(1 - Swi) / Bg”For oil – “STOIP = (t*l*w* φ)*(1 - Swi - Sg) / Bo”

Source: Blasingame TAMU

Net Pore Volume

Fluid Content

Surface Conditions

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• Net Thickness - from well logs

• Areal Extent – from seismic mapping

• Porosity – from well logs

• Hydrocarbon Saturations - from well logs

• Water Saturation – from well logs

• Formation Volume Factor – from fluid analysis

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• Total reported - “Brulpadda well encountered 57 metres of net gas condensate pay in Lower Cretaceous reservoirs”.

• First indication is from “returns” from the drilling fluid – indicates the lithology of the material brought to surface during drilling

• Second indication is from well logs. In modern drilling this is accomplished with tools integrated into the drilling string.

• Best indication comes from “coring” where formation material is brought to surface intact. However, this is not generally done on the initial well.Source : Mudaly, K.;Turner, J.; etal 2009

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• Length – about 20 km.

• Width – about 2.5 km.

• Thickness – 30 metres

Source: Africa Energy

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Source: Oil and Gas Journal 6/2005

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• “Gas Condensate Reservoir - A reservoir initially containing natural gas that will precipitate hydrocarbon liquid (retrograde condensate) during pressure depletion.” (PWC)

• “Condensate - Condensates are a portion of natural gas of such composition that are in the gaseous phase at temperature and pressure of the reservoirs, but that, when produced, are in the liquid phase at surface pressure and temperature.” (SPE)

22Source: Blasingame TAMU

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• Normal Pressure at 3500 meters– 344 bar – 5000 psi

• Given info – gas condensate

• From graph – 1/Bg = 250

• Bg = 0.004

Source: Gas and Oil Properties and Correlations Chap 3 Phase Behaviour

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• Areal extent – 20*2.5 km2 – (estimate from Africa Energy map)• Height – 30 metres (average over area)• Porosity – likely about 20%• Water Saturation – likely about 25%• Bg – assume 0.004

For gas – “G = (t*l*w* φ)*(1 - Swi) / Bg”

G= (20*2.5*1000*1000*30*0.2)*(1-.25)/0.004 = 56 * 109 m3

– 56 BCM (recovery about 45 BCM)In oilfield units, about 1.9 TCF (recovery about 1.5 TCF)

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• Areal extent – 20*2.5 km2 – (estimate from Africa Energy map)• Height – 30 metres (average over area)• Porosity – likely about 20%• Water Saturation – likely about 25%• Bo – assume 2.3

For oil – “STOIP = (t*l*w* φ)*(1 - Swi - Sg) / Bo”

STOIP= (20*2.5*1000*1000*30*0.2)*(1-.25)/2.3 = 97 * 106 m3

In oilfield units, about 600 million barrels (recovery about 200 – 300 million )

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• Condensate implies hydrocarbon is in gas phase in reservoir

• Condensate percentage can vary from small percentage to mostly oil

• Condensate comes out as liquid during production process

• 300 million barrels oil – 1.9 TCF gas equivalent on volume basis

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• “It is gas condensate and light oil. Mainly gas. There are four other prospects on the licence that we have to drill; it could be around 1 billion barrels of total resources of gas and condensate,” Pouyanne said.

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• Production Volume – 45 BCM in 20 years (80% recovery)• Daily gas /condensate volume – 6 MCM/day • Well productivity – up to about 1 MCM/day – 6 to 10 wells

• Production Cost• Mozambique gas estimated at $4/GJ from deepwater blocks• Simpler / smaller development• Liquid value subsidizes gas cost• Make use of existing facilities to reduce cost

• Value• Annual gas production – $300 million

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• Daily gas /condensate volume – 6 MCM/day (for 20 years) • Energy content (if gas) – 227,000 GJ/day

• Use for power generation Electric generation potential – 1.3 GW @ 50% eff. Peaking power – 13 GW at 10% usage Challenge is dispatchability and gas storage

• Use for liquid fuel production Condensate production will be taken directly as liquid Gas Conversion to GTL – energy loss of about 42% GTL Diesel – 3 million litres or 21,000 Barrels per day Power generation as needed with diesel

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DispatchableElectricity

Gourikwa PetroSA DieselPower Plant Refinery Condensate

oil and gas pipelines

gas

oil FA Field PlatformProcessing and Transit

Three phasepipeline(oil/gas/ water)

Brulpadda Facilities(mini-TLP or Subsea)

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1973 Soekor drills its first offshore well.

1980 Discovery of the F - A gas field in Block 9. Soekor and other parties drill 48 boreholes. The exploration discovers gas in 25 and oil in 7.

1983 Discovery of the E - M field, which together with the F - A field, provides the basis for establishing the GTL project in Mossel Bay.

1987 The GTL project in Mossel Bay is initiated.

1992 The F - A fields as well as the Mossel Bay gas - to - liquids (GTL) refinery start producing. At the time, Mossel Bay is the world's largest commercial GTL refinery.

2000 Gas production from the E - M field commences.

2007 The South Coast gas fields commence gas and condensate production.

2010 The F - O gas project is initiated. This was to augment the gas feedstock supply to the GTL refinery.

Source: PetroSA

36Source: PetroSA

Source: PetroSA

37Source: PetroSA

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Technical Details:Type: Open Cycle Gas Turbines (OCGT)Number of Units: 5Output per unit: 148MWInstalled Capacity: 740 MW

Source: Eskom Source: Google Earth

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• Timing – up to 10 years before first gas – what will be the status of PetroSA and the Mosselbay facilities?

• What is the remaining life of the existing facilities and how much renovation would be required to use for this development?

• Without these facilities, what development is likely?

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• Game Changer?• Not really • Significant find that will should add value to the SA economy• Good location to maximize value and minimize development

timing

• Results• Will challenge the potential need for shale gas exploration• Should provide needed gas, diesel and products • Should extend the life of existing facilities• Should encourage more offshore exploration

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• PetroSA Analysis of FO Field – 1.3 TCF field (29 BCM Recovery) 3 well development – implies about EUR = 10,000 MCM per well

• CSIR Karoo Shale Gas Report – EUR = 4 BCF per well recovery – 110 MCM

EUR = Estimated Ultimate Recovery

Per Offshore Well @ $100 million - $0.01 per m3

Per Shale Well @ $20 million - $0.18 per m3

Source : PASA

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ACKNOWLEDGEMENTS:

CONTACT DETAILS:

visit us: concentrating.sun.ac.za

Solar Thermal Energy Research Group (STERG)Stellenbosch University South Africa

Stephen Clark

STERG@sun.ac.za+27 (0)21 808 4016