DANMARKS OG GRØNLANDS GEOLOGISKE UNDERSØGELSE RAPPORT 201 6/5 6 Reservoir prognosis of the Gassum Formation and the Karlebo Member within two areas of interest in northern Copenhagen The EUDP project "Geothermal pilot hole, phase 1b" Henrik Vosgerau, Ulrik Gregersen, Morten Leth Hjuler, Hanne Dahl Holmslykke, Lars Kristensen, Sofie Lindström, Anders Mathiesen, Carsten Møller Nielsen, Mette Olivarius, Gunver Krarup Pedersen & Lars Henrik Nielsen GEOLOGICAL SURVEY OF DENMARK AND GREENLAND De Nationale Geologiske Undersøgelser Øster Voldgade 10 Telefon / Phone +45 38 14 20 00 DANISH MINISTRY OF ENERGY, UTILITIES AND CLIMATE for Danmark og Grønland (GEUS) DK-1350 København K Fax +45 38 14 20 50 Geological Survey of Denmark and Greenland Danmark / Denmark E-post / E-mail [email protected] Internet www.geus.dk DANMARKS OG GRØNLANDS GEOLOGISKE UNDERSØGELSE RAPPORT 20 1 6/5 6 Reservoir prognosis of the Gassum Formation and the Karlebo Member within two areas of interest in northern Copenhagen The EUDP project "Geothermal pilot hole, phase 1b" Henrik Vosgerau, Ulrik Gregersen, Morten Leth Hjuler, Hanne Dahl Holmslykke, Lars Kristensen, Sofie Lindström, Anders Mathiesen, Carsten Møller Nielsen, Mette Olivarius, Gunver Krarup Pedersen & Lars Henrik Nielsen GEOLOGICAL SURVEY OF DENMARK AND GREENLAND D A N I S H MINISTRY OF ENERGY , UTILITIES A N D CLIMATE Contents Preface 6 Résumé 8 1. Geological setting 19 2. Data basis 23 3. Sequence stratigraphic framework 26 4. Biostratigraphy 29 4.1 Palynostratigraphic framework ............................................................................... 29 4.1.1 Dinoflagellate cyst zonation of the Danish Basin ............................................... 32 4.1.2 Spore-pollen zonation of the Danish Basin ........................................................ 32 4.2 Methods .................................................................................................................. 35 4.3 Stratigraphic breakdown of the investigated wells ................................................. 36 4.3.1 Margretheholm-1 ................................................................................................ 36 4.3.2 Karlebo-1A .......................................................................................................... 40 4.3.3 Höllviksnäs-1/Höllviken-2 ................................................................................... 45 4.3.4 Lavø-1 ................................................................................................................. 49 4.3.5 Stenlille-1 ............................................................................................................ 51 4.3.6 Stenlille-2 ............................................................................................................ 55 4.3.7 Stenlille-5 ............................................................................................................ 57 4.3.8 Stenlille-6 ............................................................................................................ 58 4.3.9 Stenlille-15 .......................................................................................................... 59 4.4 Concluding remarks ............................................................................................... 59 5. Seismic interpretation and mapping 60 5.1 Database and workflow .......................................................................................... 60 5.2 Seismic stratigraphy and facies ............................................................................. 60 5.2.1 Regional well tie, stratigraphy and overall unit thicknesses............................... 61 5.2.2 Seismic facies ..................................................................................................... 61 5.2.3 Faults and folds .................................................................................................. 63 5.3 Concluding remarks ............................................................................................... 63 6. Reservoir properties 69 6.1 Petrograpy and diagenesis .................................................................................... 69 6.1.1 Samples and methods ........................................................................................ 69 6.1.2 Detrital components ............................................................................................ 70 6.1.3 Authigenic phases .............................................................................................. 71 6.1.4 Porosity and permeability ................................................................................... 72 6.1.5 Discussion .......................................................................................................... 72 6.1.6 Conclusions ........................................................................................................ 73 G E U S 3 6.2 Provenance analysis .............................................................................................. 79 6.2.1 Samples and methods........................................................................................ 79 6.2.2 Zircon ages ......................................................................................................... 79 6.2.3 Discussion .......................................................................................................... 80 6.2.4 Conclusions ........................................................................................................ 82 6.3 Reservoir prognosis ............................................................................................... 85 6.3.1 Reservoir prognosis for the western area .......................................................... 87 6.3.2 Reservoir prognosis for the eastern area ........................................................... 90 6.3.3 Geothermal potential .......................................................................................... 92 6.3.4 Estimation of reservoir parameters .................................................................... 92 7. Production capacity 101 7.1 Static and dynamic modelling .............................................................................. 101 7.1.1 Input data .......................................................................................................... 101 7.1.2 Static modelling procedure ............................................................................... 102 7.1.3 Dynamic modelling procedure .......................................................................... 103 7.1.4 Simulations cases ............................................................................................ 104 7.1.5 Results .............................................................................................................. 105 7.2 Productivity evaluation ......................................................................................... 106 8. Mineral composition of mudstones 113 8.1 Introduction ........................................................................................................... 113 8.2 Methods ................................................................................................................ 113 8.2.1 Bulk mineralogy ................................................................................................ 113 8.2.2 Clay mineralogy ................................................................................................ 114 8.3 Results ................................................................................................................. 115 8.3.1 TOC content ..................................................................................................... 115 8.3.2 Silt content ........................................................................................................ 115 8.3.3 Bulk mineralogy ................................................................................................ 117 8.3.4 Clay mineralogy ................................................................................................ 122 8.4 Discussion ............................................................................................................ 123 8.5 Main results .......................................................................................................... 124 9. Formation damage control 125 9.1 Introduction ........................................................................................................... 125 9.2 Formation damage ............................................................................................... 125 9.2.1 Clay swelling..................................................................................................... 125 9.2.2 Fines migration ................................................................................................. 126 9.3 Formation damage control ................................................................................... 127 9.3.1 Identification of formation damage ................................................................... 128 9.3.2 Quantification of reservoir formation damage .................................................. 129 9.3.3 Remediation of formation damage ................................................................... 129 9.3.4 Prevention of formation damage ...................................................................... 130 9.4 Concluding remarks ............................................................................................