The Triassic Main Buntsandstein play New prospectivity in the Dutch northern offshore

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Kortekaas¹, Ulf Böker², Cas van der Kooij³, Bastiaan Jaarsma¹ and Eveline Rosendaal¹ ¹ EBN, the

1 The Triassic Main Buntsandstein play New prospectivity in the Dutch northern offshore Mesozoic Resource Potential in the Southern Permian Basin, 8-9 Sept 2016, London Top RBMVL (mtvd) Marloes Kortekaas¹, Ulf Böker², Cas van der Kooij³, Bastiaan Jaarsma¹ and Eveline Rosendaal¹ ¹ EBN, the Netherlands. ² PanTerra Geoconsultants ³ Utrecht University 11 april

Introduction Currently no Triassic fields in Dutch northern offshore General perception: Thick ZE prevents HC migration into Trias Thinning/shaling out of sst packages

2 Introduction Currently no Triassic fields in Dutch northern offshore General perception: Thick ZE prevents HC migration into Trias Thinning/shaling out of sst packages towards north Only 20 wells have been drilled in study area (17000 km 2 ) with MBU as primary/secondary target. 11 of these wells: invalid tests of the play Terracube 11 april

3 Introduction northern provenance?? Well locations with Solling fluvial sands sourced from Ringkøbing-Fyn High (Olivarius et al., 2015) 11 april 2017 Source: Southern Permian Basin Atlas 3

4 Presentation outline Regional geology 5 countries-area Indications for local sediment provenance (DK and UK) New data: biostratigraphy, heavy minerals, grain size analyses New Triassic prospectivity away from main fairway 11 april

5 Stratigraphic subdivision of the Triassic Main Buntsandstein Subgroup (MBU) 5 Source: van der Kooij, 2016

6 Northern Early Triassic sands: local provenance? RB_B Arfai et al., 2014 RBMVL_T EBN, april

7 Where are the structural highs? OGA 2D seismic lines could help define outline in UK 11 april

8 Northern reservoir provenance? A05-01 A15-01 Southern provenance (thin RBMVL, low N/G) B13-01 Southern provenance ( classic RBMVL, low N/G) F04-01 Fluvial sands with northern provenance may have developed as reservoir in the northwestern area. Southern provenance (thick RBMVL, high N/G) D12-04-S1 Southern provenance ( classic RBMVL, high N/G) F april GR DT RHOB

9 TWT TWT Early Triassic thickening: depocentre at A15-01? A15-01 A15-01 A18-01 A april van der Kooij, MSc-thesis 2016

10 A05-01, Bertel-1: potential for Keuper Schilfsst? A05-01 Bertel-1 Bertel-01 (1992) Inconsistencies in biostrat. analysis reported Trias-/Jurassic boundary doubted A15-01 RBMVL_T EBN, 2015 RB_B Arfai et al., 2014 A05-01 (1999 Amerada Hess) Limited info on nlog 2016: Biostrat analyses by TNO: Late Jurassic/Early Cretaceous strata present as well as (Carnian?) Triassic strata TNO, 2016: biostratigraphical analysis 11 april

11 A05-01, A15-01, A18-01: grainsize analysis A05-01 Bertel-1 A18-01 RB_B Arfai et al., 2014 A15-01 RBMVL_T EBN, april Bezemer, BSc-thesis 2016

12 Intermediate results heavy mineral analyses A05-01 A15-01 A18-01 Variscan? MNSH? Variscan? Variscan? Fennoscandian? Shetland Islands? 11 april Vonk, BSc-thesis 2016

13 Top Lower Volpriehausen Sst depth map - Prospectivity 3 1 RB_B (depth) from Arfai et al., 2014 Three types of leads: 1) classic leads with proven types of trap, source, seal and reservoir 2) leads which may be sourced with HC s via Tertiary volcanic dykes 3) leads with local reservoir provenance area 2 RBMVL_T (EBN) UK Triassic gas fields that are sourced from the Carboniferous via Tertiary volcanic dykes. The dykes extend into the Dutch sector with leads lining up along11 their april strike

14 Charge mechanisms Three charge mechanisms: Salt windows (ZE thickness) Faults Volcanic dykes Analysis per lead is required 11 april

$fields UK charged via fractures near volcanic dykes (a.o. Underhill, 2009).$

15 Charge via volcanic dykes Thick ZE: charge bypassed ZE via volcanic dykes Significant lateral HC migration A A Amplitude extraction at base Tertiary A 11 april 2017 MBU gas fields UK charged via fractures near volcanic dykes (a.o. Underhill, 2009). Tertiary dyke trend UK (Kirton and Donato, 1985) Tertiary dyke trend UK (Underhill, 2009) km A

16 Source Rock potential (Lower Carboniferous coals) Coals N-ward increase in Lower Carboniferous coal content (Scremerston Fm.) Yoredale Fm and Namurian also contain coal; up to 7.5 m encountered in wells. 8 m coal 23 m coal 30 m coal 2 m coal 11 april

17 Leads 53 structures P50 GIIP of ~87 BCM (unrisked) Closures also located in open acreage 11 april

18 Conclusions New prospectivity away from the main fairway Local reservoir development Potential for Upper Triassic reservoirs? Work in progress We welcome any suggestions: 11 april

19 Thank you for your attention More information? Contact us: Acknowledgements: Fugro and Spectrum ASA, for giving permission to show data from the DEF survey EBN Colleagues, students Utrecht University: Aike Vonk (heavy mineral analysis) and Gioia Bezemer (grain size analysis) 11 april 2017 References: Southern Permian Basin atlas (2010) Geology of the Netherlands (2007) Arfai et al. (2014), Late Palaeozoic to Early Cenozoic geological evolution of the Entenschnabel, NJG. Olivarius et al. (2015), Provenance of the Lower Triassic Bunter Sandstone Formation, Basin Research. Van der Kooij, C. (2016), Triassic sand development in the northern Dutch offshore (MSc thesis Utrecht University) Vonk, A. (2016), Provenance of Lower Triassic sands in the northern Dutch offshore (BSc thesis, Utrecht University) Bezemer, G. (2016), Grain size analysis of the Triassic Main Buntsandstein Subgroup in the northern Dutch offshore (BSc thesis, Utrecht University) TNO, 2016: biostratigraphical analysis carried out for EBN. 19

The Triassic Main Buntsandstein play in the Dutch northern offshore

Poster #7 The Triassic Main Buntsandstein play in the Dutch northern offshore New prospectivity away from the main fairway Marloes Kortekaas*, Bastiaan Jaarsma, Ulf Böker, Cas van der Kooij and Eveline