30 August 2017
Event phone: +44 (0)20 7408 2000
Review by Dhiman Majumder, Consultant Geologist, Geotek Private Limited
A group of 25 industry professionals attended the ‘Petroleum systems of North Africa and the Mediterranean’ course at the Double Tree Hilton Hotel in Islington on 30th of August’2017. The course was delivered by Duncan MacGregor and David Boote.
The day started off with Duncan setting the scene with exploration history and current trends in the region. This was followed by David taking us through about the Onshore Palaeozoic to Triassic stratigraphy and petroleum systems. The three Palaeozoic petroleum systems (Triassic evaporite sealed, intra-Palaeozoic shale sealed, extinct? or near extinct) and their associated elements were explained. Possible lack of source rock in Kufra and post charge destructive processes in Tindouf were suggested as the main reason for the disappointing results. Duncan then took us through the Mesozoic – Cenozoic tectonics and paleogeography through a series of palinspastic reconstructions. It was very interesting to note how the different rift systems jumped from one basin to another over time.
Following the coffee break, David introduced to us the Sirte petroleum province and took us through the different petroleum systems (Nubian, Bahi-Tasgrifet, Waha & equivalent, Ypper Satal-Defa, Beda, Zelten-Intisar and Facha). A little bit of time was spent talking about the relatively under explored Western desert and unusual Jurassic oil prone coals as source rocks. This was followed by a play risk assessment exercise over Gulf of Sirte based on regional maps, sections and field analogues that took us to lunch.
Duncan kicked off the afternoon session with Mediterranean petroleum systems. Out of the 25 largest Mediterranean offshore fields, only six of them were oil and out of those only two (Vega in Sicily & Casablanca in Valencia) are on the European plate. The creaming (non!) curve and field size distributions of North Africa looked very immature. Biogenic gas distribution over the Mediterranean was shown and key factors affecting biogenic gas was talked about. Seismic section over Aphrodite, Leviathan and Tamar was shown as an example of early formed traps (near syn sedimentary structuring). It was interesting to know that although Tamar is believed to be biogenic, there must be some thermogenic contribution to it as otherwise it couldn’t be full to spill with a reservoir temperature at 78 deg C.
Prior to afternoon tea, Duncan took us through the contrasting features of the Western and Eastern Mediterranean. The Western Mediterranean is a much younger ocean compared to the Eastern Mediterranean. An overview of tectonic controls affecting the Nile Delta sedimentation & resultant facies variation from Levantine basin across Eratosthenes ridge to Herodotus basin was given. Post tea, we embarked on a reservoir play fairway definition exercise. We were given seismic lines & a base map and the exercise was to delineate the extent of Early Miocene sand fairway committing to different probabilities of occurrence (P90, P50 and P10) and to outline frontier areas (Lebanon) where these reservoirs are most likely to be present. This exercise took us to the close of play.
Participants left armed with a course manual, soft copy and a good overview of petroleum systems of North Africa and Mediterranean region. The pace of the course was fast and both Duncan and David did an excellent job in keeping us all awake through the graveyard shift! On my way back home, I kept thinking how many times one would have to fill up (& dry!) the present Mediterranean to generate 1km thick salt! Thanks to both the presenters and PESGB on behalf of all the participants.
The Tamar, Leviathan and Zohr discoveries have revitalised interest in North Africa and the Mediterranean. This course is an abbreviated version of the original 3 day PESGB North Africa course and is designed to provide participants with a regional overview to back up their own block and prospect-specific interpretations. Discussions are focussed round a series of paleotectonic reconstructions, paleogeographic maps, play cross-sections and chronostratigraphic charts over the region (provided in a manual), with particular attention given to the newer petroleum systems such as biogenic gas plays. Countries covered include Algeria, Tunisia, Malta, Sicily, Libya, Egypt, Cyprus, Israel and Lebanon. Two regional exercises focus on crystallising the learnings of the course for fairway and prospect evaluations.
In conjunction with
DoubleTree by Hilton London – Islington