An Interview with Steven Noske: Hydrocarbon exploration in the Seychelles Part 1/2

Originally posted August 26th, 2018

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Steven Noske talks about hydrocarbon exploration and geological merit of the Republic of the Seychelles.  From 2010 to 2015 Noske led an effort to improve the geological understanding of the Seychelles aiming to undertake the necessary pre-work to underpin drilling of the first exploration well since the 1980’s.

 

Why consider The Seychelles?

 

 

Over the period 2016 to 2018, frontier hydrocarbon exploration has virtually ceased with the downturn in oil price and a flight of the capital markets from risk.  Prior to 2015, company Boards were willing to consider exploration in higher risk, frontier areas.

As we come to the back end of 2018 and with oil price holding around USD70 per barrel we are starting to see a very gradual return to frontier, higher risk exploration with company’s now starting to position themselves in these plays.

Up to 2015, the Republic of the Seychelles had Ophir Energy plc, WHL Energy, AFREN and JOGMEC.  Only JOGMEC remain with JOGMEC, a Japanese oil company, continuing to explore around Seychelles but without significant conviction.  The Japanese National Oil Company (JOGMEC) was the only one undertaking exploration activities in Seychelles’ waters after it extended its license for another two years in February 2016.

The Seychelles opened a wide portion of their EEZ to bidding in 2014 in has not successfully concluded any award of exploration rights.  So why consider The Seychelles now. Steven Noske says that organizations should now look to re-acquaint themselves with the merits of The Seychelles.  He is of the view that The Seychelles represent:

  1. An East Africa oil play which has seen success in the past
  2. A Basin-opener opportunity
  3. A material opportunity with several multi-hundred million-barrel structures up dip from active kitchens
  4. An opportunity to secure a strategic acreage position covering up to 20,000 km2 by bidding on two areas of higher interest (in Noske’s view)
  5. Low Cost drilling
    1. Moderate drill target depths (~2,000m) in shallow water (< 50m) with benign metocean conditions mean jack up drillable with controllable costs
  6. A government with excellent petroleum fiscal regime
    1. Administered by a pragmatic, business – oriented government

 

 

Give the reader an overview of The Seychelles.

In my view exploration should focus on an extensive acreage position in the Seychelles that covers a large part of the southern and eastern margin of the under explored Seychelles micro-continent (Fig 1).

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Fig 1: Seismic

Organizations should focus on up to two 10,000 km2 blocks where water depths are generally around 50 m.

The Seychelles has been very lightly explored, with only 4 wells drilled between 1979 and 1995, none of which were valid tests, in a 40,000 Km2 frontier potential petroleum province.

The region is oil prone with an inventory of leads and prospects that includes giant scale structures positioned immediately up dip from mature kitchen areas and generally located in shallow water. My team mapped an inventory of over 30 leads and prospects in the past.

Our team conducted a fully integrated geoscience study conducted involved some 10 man years of work, including the interpretation of over 28,000 line km of vintage and new 2D seismic. In particular these “Gamechanger Studies” have leveraged improved seismic imaging from the Fugro 2010 MC2D survey covering 9,858 km which is available for licensed. This data has been integrated with newly published information relating to East African petroleum systems arising from the escalating industry activity in the region. Importantly new 3D seismic has been undertaken in 2015 which, when integrated with the works undertaken in the past, provide new insights into the regions potential.

The Republic of Seychelles is politically stable with well-developed governance processes and arguably the best petroleum fiscal terms in the region.  The Seychelles finalised a revision of the Petroleum Agreement terms they are looking to agree with new exploration partners in 2013.

The Seychelles represents an opportunity for companies seeking an early stage, high potential exploration assets with a favourable cost profile.

Tell us about the Fiscal Regime in The Seychelles.

 

 

The Seychelles has developed a Petroleum fiscal system that represents best practice in Africa and I encourage readers to review the Petro Seychelles website for further information at;

http://www.petroseychelles.com/index.php/legal-issues/model-petroleum-agreement

In summary, the terms are straight forward, based on modern petroleum taxation practices, and are sufficiently flexible to cater for all likely exploration, developments and production scenarios. 

What is your view on the prospectivity of The Seychelles?

 

 

Is must be understood that The Seychelles micro-continent is a remnant of Gondwana resulting from the break up of Eastern Africa, Madagascar and India.  It is not a volcanic island. Billion-barrel petroleum systems are associated with this break-up, for example the Bemolanga and Tsimoro heavy oil fields on Madagascar in the Triassic–Jurassic Karoo succession (Fig 3).

The presence of an active oil prone petroleum system in the Seychelles is indicated by the presence of shows in the Reith Bank-1 which geochemically correlate with Jurassic source rocks penetrated in the Owen Bank-1 well, and tar ball occurrences and beach strandings which can also be correlated to potential Jurassic and Cretaceous source intervals in the Seychelles.  

In the past my team mapped the related basin ward, kitchen areas. The Jurassic source sequence is equivalent to that which fuels the Rovuma Delta discoveries in Tanzania and Mozambique. Unlike those areas which are gas prone due to deep burial beneath a wedge of Tertiary sediments, the Seychelles kitchen areas have not been as deeply buried and are largely within the oil generative window. We had undertaken a comprehensive basin model to determine the volumetric potential and charge characteristics for these individual kitchen areas.
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The regional Karoo Group, Isalo Formation (Triassic – Early Jurassic age) sandstone reservoir is widespread across the Company’s acreage and is deemed the primary reservoir target with porosities ranging 12% -20% and permeabilities in the 100’s of mD measured from DST’s in the Reith Bank-1.

The south-eastern margin of the Seychelles Plateau is, in my opinion, the most prospective area on the Seychelles Platform due to the potential for Tertiary hydrocarbon (oil) charge. The area is characterised by the presence of a Mid–Late Cretaceous basin (the Correira Basin) related to the rifting between the Seychelles and Madagascar. This area also has an expanded Paleocene section resulting in later loading and early Tertiary generation and expulsion from Cretaceous to Jurassic potential source rocks. These source sequences are interpreted to charge very large, conventional Karoo tilted fault blocks and horsts in the Junon prospect area, immediately updip.

Significant thicknesses of Jurassic – Cretaceous marine shale is interpreted to be preserved over the major structures in the south-eastern margin, providing a good potential seal to these fault blocks.

The Junon South trend in particular is a focus for migration from the southeastern source kitchen and is thought to be the lowest risk play in the region. It is a potential “basin opener” opportunity.

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Fig 5: Summary of Cretaceous-sourced petroleum system of eastern Seychelles

A conventional Karoo petroleum system is interpreted to be present in the Beau Vallon area to the west of the Seychelles Platform. Several large tilted faults blocks potentially with stacked Karoo reservoirs have been mapped. These very large structures are interpreted to have been charged from Triassic–Early Jurassic Karoo and Middle Jurassic Somali syn-rift source rocks. Beau Vallon is analogous to the oil discoveries in the Morondava Basin, Madagascar.  

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