The PESGB thank ConocoPhillips for sponsoring this Aberdeen Evening Lecture

North Sea Pre-Zechstein Palaeozoic Sourced Play

Douglas Moore, ConocoPhillips

Tuesday 16th September 2008, 6pm for 6.30pm presentation
 Copthorne Hotel, 122 Huntly Street, Aberdeen AB10 1SU

Recently, industry analysts and the Press have declared North Sea new ventures exploration to be immaterial to supermajors.  As a result of this general attitude, securing enthusiastic management support for a previously unsanctioned, new ventures growth play proved a challenge.  Nonetheless, ConocoPhillips North Sea New Ventures aggressively entered the Pre-Zechstein play through 1.)Demonstrating a thorough understanding of the geological province, 2.) Employing an extensive database of heritage and new data, 3.) Asking the correct ‘what if’ questions and perhaps most importantly, 4.)Securing the support and time to compile, coalesce and interpret various data into a robust regional geologic story. 

The Pre-Zechstein play is premised on the notion that significant non-Kimmeridgian sourced exploration opportunities exist in the Northern Permian Basins in the North Sea. If an older source interval can be proven, new areas of frontier exploration could open up.  Although this idea is not unique to ConocoPhillips, the Company’s historic position in the Southern North Sea allowed this hypothesis to be convincingly applied.    

The play falls into the high risk, high reward category and the term “Pan North Sea Pre-Zechstein Plays” is used to define reservoirs sourced by interpreted Palaeozoic basins in the UK and Norway.  

The deep Palaeozoic section, namely the Devonian-Carboniferous source-prone interval, has not been penetrated in many of these basins. Source basin location, stratigraphy and facies is constrained by indirect data in the form of gravity & magnetic data, seismic data and regional geological models. Recently acquired 2D long-offset data covering many of the basins has facilitated a step-change in understanding the Palaeozoic basin evolution and basin-fill. The primary source rock interval is considered to be syn-rift Dinantian-Namurian organic-rich coals and shales similar to the Westphalian prolific source rocks for the Rotliegendes and Carboniferous gas fields of the Southern North Sea and the Netherlands. 

The primary reservoir objective is sandstones of the Permian Rotliegendes Group overlain by a Permian Zechstein salt seal. Additional potential reservoir objectives include Carboniferous and Devonian sandstones and younger reservoirs in basins where the Zechstein salt and/or Triassic shale seals are absent or breached.  

Prior drilling by other operators has tested the play, however post drilling analysis, including fluid inclusion sampling, regional structural and stratigraphic modelling and integration of new seismic data, has highlighted predictable failure factors.  From the same analyses, high-graded areas of reduced risk have been identified.  Three multi-block license areas, one in the UK and two in Norway, have been acquired: P1432 in the UK (100% ConocoPhillips); PL331 in Norway (40% ConocoPhillips, operator, 40% StatoilHydro, 20% Petoro); PL404 in Norway (100% ConocoPhillips).  Multi-TCF opportunity potential has been identified, and the first-entered license area, PL331 will be tested in 2009.  

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