Arran Field Case Study: From conceptual model to Reservoir ...

1 BDana PetroleumArran Field Case Study: Arran Field Case Study: From conceptual model From conceptual model to Reservoir modelto Reservoir modelJamie CollinsJamie CollinsDana PetroleumDana PetroleumDEVEX 2011 DEVEX 2011 DEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model2 Dana Petroleum15 June 2011 Contents Acknowledgments Arran Field introduction and project objectives Project strategy conceptual model Key data observations Core Outcrop analogues Seismic Static Reservoir modelling ConclusionsDEVEX 2011 - Arran Field Case Study.

2 From conceptual model to Reservoir model3 Dana Petroleum15 June 2011 Acknowledgments Partners Esso Exploration & Production UK Shell UK Dyas Ruhrgas UK E&P Dana team Natalie Bordas-Le Floch Jamie Collins Brian Cullen - Reservoir Associates North Sea John Downey Steve Kenyon-Roberts Paul Mattson - Logios Consulting Jason WhiteDEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model4 Dana Petroleum15 June 2011 Arran Field located 240km east of Aberdeen Central Graben - Blocks 23/11 & 23/16 Gas condensate Field Palaeocene Forties Sst Member Reservoir Medial Forties turbidite system Eastern margin on-laps onto Jaeren High Structure Arran North - Reservoir pierced by Zechstein salt diapir Arran South Stratigraphic pinch-out to east.

3 With local low relief four way dip closure Project objectives Incorporation of new 2010 3D seismic data Reinterpretation of all existing data Support detailed well planning 3 well developmentArran Field IntroductionArranRedrawn from Fraser et al., 2003 Petrostrat Regional StudyNorthern North SeaMoray FirthCentral North SeaEast Shetland PlatformHorda PlatformCentral GrabenWest Central ShelfUtsira HighWitch Ground GrabenNorth Viking GrabenCentral Viking GrabenSouth Viking GrabenJaeren HighInner Moray FirthOuter Moray FirthTail End GrabenMid North Sea HighFladen Ground SpurRedrawn from Fraser et al.

4 , 2003 Redrawn from Petrostrat Regional StufyArran FieldDEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model5 Dana Petroleum15 June 2011 Forties Sst pinch-out marginArran NorthArran South Arran Field located 240km east of Aberdeen Central Graben - Blocks 23/11 & 23/16 Gas condensate Field Palaeocene Forties Sst Member Reservoir Medial Forties turbidite system Eastern margin on-laps onto Jaeren High Structure Arran North - Reservoir pierced by Zechstein salt diapir Arran South Stratigraphic pinch-out to east.

5 With local low relief four way dip closure Project objectives Incorporation of new 2010 3D seismic data Reinterpretation of all existing data Support detailed well planning 3 well developmentArran Field IntroductionDEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model6 Dana Petroleum15 June 2011 Base UKHordaSeleForties Fm Ekofisk BCUTop TriassicTop saltRotliegend / Base SaltBase FortiesTriassicS1 kmSalt23/16b-10 Arbitrary Line 1992 23/16 3D Shell Reprocessed 2003 PSTMF orties Seismic PinchoutWELineLocationFortiesArran Seismic Cross SectionCGGV Quad 22 Regional Survey 2008 DEVEX 2011 - Arran Field Case Study.

6 From conceptual model to Reservoir model7 Dana Petroleum15 June 2011 Arran Field Data Well data 6 wells in immediate area, ~50% of Reservoir interval in wells cored Core coverage over entire Forties stratigraphy Wells located along axis of Forties fairway Biostratigraphic, log & MDT data Limited DST data CGG Veritas Quad 22 Regional 3D Survey 2008 Reprocessed 2010 to PreSDM Seismic inversion fluid cube Seismic Vshale volume Partner analogue data from nearby fields Technical and production experience Reservoir connectivityDEVEX 2011 - Arran Field Case Study.

7 From conceptual model to Reservoir model8 Dana Petroleum15 June 2011 Project StrategySeismicOutcrop AnaloguesCoreSeismic AttributesConceptual ModelKnowledge SharingStratigraphic FrameworkDEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model9 Dana Petroleum15 June 2011 Forties Reservoir conceptual model Arran Field depositional settings Medial parts of Forties turbidite system Eastern margin thins and pinches out against Jaeren High Preliminary core interpretations show Stacked amalgamated and non- amalgamated fairway sandstone bodies High density turbidites Extensively interbedded with Heterolithic low density turbidite fringe deposits Slumps & debris flows Hemipelagic and turbiditic shales Moderate

8 NTG system with poor Reservoir quality Thin heterolithic facies Avg. net porosity ~15% Avg. net permeability ~5mDFrom Hempton et al, 2005 Sele Fm ReservoirsArranDEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model10 Dana Petroleum15 June 2011 Central fairway submarine channels and amalgamated sands `Non amalgamated sands passing laterally into lobe marginsThin bedded lobe fringes passing laterally into interlobe / abandonment shalesForties Reservoir conceptual model Tabular elongated turbidite lobe bodies - high density turbidites Axial amalgamated lobe bodies.

9 Passing laterally towards heterolithic lobe fringes Lateral migration of lobes over time conceptual model evolved through project life cycle, along with Field interpretationsDEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model11 Dana Petroleum15 June 2011 Sandy Debrites & Slumps, 4 Interlobe / Abandonment Shale, 15 Channels & Amalgamated, 12 Non Amalgamated, 22 Thin Bedded Lobe Fringe, 10 Muddy Debrites, 14 Lobe Margin,24 Arran Core & Facies Interpretations ~50% of Arran Reservoir interval cored Detail core facies interpretation 7 key facies identified Grouped into depositional units to assist with Reservoir modelling Moderate NTG system dominated by non amalgamated and lobe margin facies Lack of large erosive channel units Average bed thickness dependent on facies Typically <50cm due to heterolithic facies Low energy lobe environment Consistent with medial but marginal location within Forties turbidite system Poorer average

10 Reservoir quality than typical Forties fields Dominated by thin heterolithic Reservoir units High proportion of thin heterolithic faciesDEVEX 2011 - Arran Field Case Study: From conceptual model to Reservoir model12 Dana Petroleum15 June 2011 Non-Amalgamated Facies Massive and dewatered high density turbidites Beds are discrete depositional units, separated by preserved low energy bed tops Non-Amalgamated & Lobe Margin FaciesLobe Margin Facies Interbedded high density turbidites Linked debrites with muddy debrites Thin-bedded turbidites and slumpsImplications for static modelling and Reservoir performance?