GEOL40310_LectureA05_Exploration2_2023.pdf

Geol 40310 Fossil Fuels and Carbon Capture & Storage (CCS) Lecture A5: Exploration 2: Exploration Examples Autumn 2023-24 T. Manzocchi, University College Dublin 1 1 Exploration 2. Exploration Examples Selected Petroleum Provinces of NW Europe The North Sea The Permo-Triassic Rotliegend system Th...

Geol 40310 Fossil Fuels and Carbon Capture & Storage (CCS) Lecture A5: Exploration 2: Exploration Examples Autumn 2023-24 T. Manzocchi, University College Dublin 1 1 Exploration 2. Exploration Examples Selected Petroleum Provinces of NW Europe The North Sea The Permo-Triassic Rotliegend system The Jurassic Brent system Cretaceous chalk reservoir system Paleogene turbidite (deep-water deposit) system Irish Exploration: Discoveries offshore Ireland Slyne and Erris Basins: The Corrib Field Porcupine Basin: The 2013 Dunquin well The 2017 Druid/Drombeg well 2 2 GEOL 40310 Lecture A5 1 3 Lundin and Dore (2005) 3 Recoverable reserves (million boe) “Creaming curves” for areas of the UKCS NNS CNS EIS SNS Drilling sequence number Source: UK Department of Energy & Climate Change • The Shape of a creaming curve indicates maturity of the province. • In this example, the curves suggest that the Central North Sea and West of Shetlands are the provinces most likely contain major undiscovered reserves. 4 4 GEOL 40310 Lecture A5 2 Recoverable reserves (million boe) “Creaming curves” for areas of the UKCS Northern North sea: Brent system Central North Sea: Cretaceous chalk and Palaeogene turbidite systems Southern North Sea: Rotliegend system Source: UK Department of Energy & Climate Change 5 5 Petroleum Systems of the North Sea Paleogene turbidite reservoirs Brent Province reservoirs Chalk reservoirs Rotliegend Province gas reservoirs 6 GEOL 40310 Lecture A5 3 Petroleum Systems of the North Sea Palaeogene turbidite reservoir rock Cretaceous chalk reservoir rock Kimmeridge Clay source rock Brent Province Shallow marine reservoir rock Rotliegend continental sand reservoir rock Coal Measures source rock Reservoir rocks Source rocks NB Seal rocks not shown here 7 7 Carboniferous(300 Ma) 8 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 8 GEOL 40310 Lecture A5 4 The Carboniferous Period e.g. South Wales, looking south Variscan Mountain chain Swamps and rivers – Future coal and gas-prone source rocks 9 9 Permian - Triassic (250 Ma) 10 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 10 GEOL 40310 Lecture A5 5 Base Permian Unconformity Permian Rocks Unconformity Carboniferous Rocks Base Permian Unconformity, Portugal 11 11 Modern-day analogue for Permian depositional environment: Death Valley, California. 12 https://www.plumdeluxe.com/death-valley-photos 12 GEOL 40310 Lecture A5 6 Modern-day analogue for Permian depositional environment: Wadi and Dunes, Sahara Desert, Algeria 13 13 Modern-day analogue for Permian depositional environment: The great Salt Lake, Utah, USA www.americansouthwest.net 14 14 GEOL 40310 Lecture A5 7 Aeolian (i.e. wind-blown) deposits – Good reservoir rocks Navajo Sandstone, Utah 15 15 Evaporite Deposits – good seal rocks 16 Carnallite: (potassium magnesium chloride) mines , Yekaterinburg 16 GEOL 40310 Lecture A5 8 The Rotliegend Petroleum system Seal - Evaporites Reservoir rock – aeolian deposits Source rock (NB Coal measures: Type 3 kerogen is a source rock for gas) 17 http://pubs.usgs.gov/bul/b2211/b2211.html 17 The Rotliegend Petroleum system 18 http://pubs.usgs.gov/bul/b2211/b2211.html 18 GEOL 40310 Lecture A5 9 Southern North Sea gas fields Peak rate ca. 2 TCF / year West Sole Indefatigable Leman Bank (TCF: Trillion cubic feet) Initial Reserves West Sole: 2.4 TCF Leman Bank: 11.5 TCF Indefatigable: 4.5 TCF 19 19 Groningen Gas Field, The Netherlands Discovered by Shell in 1959. Initial reserves: 73 TCF Production started in 1963 and a few years ago was expected to continue until 2060. 20 20 GEOL 40310 Lecture A5 10 Groningen Gas Field, The Netherlands • Increased magnitude and frequency of earthquakes above Groningen. • Cause of seismicity is reservoir compaction from gas withdrawal. Bourne et al. (2014) 21 21 Groningen Gas Field, The Netherlands Gas Production 1963 – 2020 Production induced earthquakes, 1991- 2021 2016 – Governmental decision to limit extraction. 2019 - Announcement to terminate production altogether in 2022. 22 22 GEOL 40310 Lecture A5 11 Permian - Triassic (250 Ma) 23 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 23 Triassic (225 Ma) 24 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 24 GEOL 40310 Lecture A5 12 Early Jurassic (200 Ma) 25 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 25 Shallow marine depositional Environment Saloum Delta, West Africa 26 Went et al. (2013) 26 GEOL 40310 Lecture A5 13 Deltaic deposits, Book Cliffs, Utah (Steel et al. (2012) 27 27 The North sea rift system 28 GEOL 40310 Lecture A5 14 Late Jurassic (150 Ma) 29 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 29 Weight %, total organic carbon 40% Late Jurassic Kimmerdge Clay Formation: Source rock for may North Sea Reservoirs 100m 0% Jenkyns et al. (2002) 30 30 GEOL 40310 Lecture A5 15 Early Cretaceous (125 Ma) 31 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 31 Late Cretaceous (75 Ma) 32 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 32 GEOL 40310 Lecture A5 16 Brent Province Reservoirs: cross-section 33 33 Norwegian oilfield production by Field Highlighting Brent province reservoirs Oseberg Gullfaks Million barrels/day Ula Statfjord 34 34 GEOL 40310 Lecture A5 17 Late Cretaceous (75 Ma) 35 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 35 Chalk Reservoirs SEM Photomicrograph of Chalk porosity. (Strand et al. 2007) 36 36 GEOL 40310 Lecture A5 18 Naturally-fractured Chalk Reservoirs Faults and fractures in chalk at Flamborough Head (England) Natural Fractures at Ekofisk result in an effective permeability of 50-100 mD despite matrix permeabilities < 1 mD 37 37 Norwegian oilfield production by Field Highlighting Ekofisk reservoir Oseberg Gullfaks Ekofisk Million barrels/day Ula Statfjord 38 38 GEOL 40310 Lecture A5 19 Eocene (50 Ma) 39 Ron Blakey, Colorado Plateau Geosystems Inc: http://cpgeosystems.com/europaleogeography.html 39 Paleogene turbidite plays, Cental North Sea Top Sele BCU Eldrett et al (2015) 40 40 GEOL 40310 Lecture A5 20 Historical and forecast Oil production, North Sea Mainly Brent Mainly Tertiary reservoirs reservoirs History Forecast UK http://www.slideshare.net/LoudenDW/uk-oiloutput-50-percent-higher-by-2018 Mainly Tertiary reservoirs Tertiary Johan Sverdrup Reservoir Norway Ekofisk 41 http://fractionalflow.com/2014/04/ 41 42 Lundin and Dore (2005) 42 GEOL 40310 Lecture A5 21 Oil and Gas Exploration - Ireland 43 43 Basins and discoveries, offshore Ireland 44 Shannon (2018) 44 GEOL 40310 Lecture A5 22 Exploration success rate ca. 1 in 10 Michael Hanrahan & Clare Morgan Petroleum Affairs Division Department of Communications, Energy and Natural Resources 45 Atlantic Ireland, 20 October 2014 45 After 43 wells:700 million barrels o.e Source: Caulfield & Corr, 2015 http://www.offshore-mag.com/articles/print/volume75/issue-8/north-sea/industry-reassessing-potential-ofirish-atlantic-margin.html Skugard Goliath Norwegian Barents Sea: After 43 wells:2200 million bbl o.e. Source: NPD Snøhvit 46 46 GEOL 40310 Lecture A5 23 Exploration in the Slyne and Erris Basins, Offshore Ireland Erris Basin Slyne Basin Porcupine Basin Northern tip of O’Sullivan et al. (2020) 47 The Corrib field, Slyne Basin O’Sullivan et al. (2020) 48 GEOL 40310 Lecture A5 24 Slyne and Erris Basins, Offshore Ireland Source rock: Carboniferous Coal measures Reservoir rock: Corrib Sandstone formation Seal rock: Uilleann halite member O’Sullivan et al. (2020) 49 Exploration in the Porcupine Basin, Offshore Ireland Whiting et al. (2020) 50 GEOL 40310 Lecture A5 25 The Dunquin Well: 2013 51 51 The Dunquin Well: 2013 Dunquin structure: Tilted fault block? Volcanic ridge? Well results: Residual oil column in an overpressured high porosity carbonate. Proof of working petroleum system in this previously unexplored region 52 Naylor and Shannon (2012) 52 GEOL 40310 Lecture A5 26 Concession Map 2014 Concession Map 2016 53 53 Conjugate Margins Plate reconstruction 200 Ma East Orphan Basin Cumulative reserves (billion barrels of oil equivalent) Welford et al. (2012) Porcupine basin 10 Exploration creaming curve 9 8 7 Newfoundland and Labrador (Nalcor 2015) 6 5 4 3 2 Irish Atlantic Margin (Caulfield and Corr 2015) 1 0 0 50 100 Number of wells 150 200 54 54 GEOL 40310 Lecture A5 27 Deep-water exploration Industry definitions: Deep water: >500m Ultra-deep water: >1500m 500m 1500m Druid / Drombeg ultra-deep water well. 2200 water depth. Drilled summer 2017 55 55 Ultra-deep Water drilling – Porcupine Basin Summer 2017 Drill-ship: $185,000 per day 500m 1500m Druid / Drombeg prospect 2200 water depth 56 56 GEOL 40310 Lecture A5 28 57 57 Offshore drilling for Oil and Gas, Ireland, 2005 - 2019 Druid / Drombeg: Iolar: Dunquin (Providence) (CNOOC) (ExxonMobil) ENERGY SECURITY IN IRELAND 2020 Report, September582020 58 GEOL 40310 Lecture A5 29 Status of oil and gas exploration, Ireland July 2019: Climate Emergency Bill, calling for a ban on issuing oil and gas exploration licenses is passed by majority vote twice by the Dáil but is killed off by budgetary considerations. September 2019: Taoiseach Leo Varadkar tells the UN that Ireland will stop oil exploration but will continue to explore for gas as a transitionary fuel. This Oil Exploration Ban policy agreed by Government in October 2019. July 2020: The Programme for Government pledges to stop issuing licences for gas exploration on the same basis as the oil exploration ban agreed by the previous government. 59 59 Exploration 2. Exploration Examples Selected Petroleum Provinces of NW Europe The North Sea The Permo-Triassic Rotliegend system The Jurassic Brent system Cretaceous chalk reservoirs Paleogene turbidite (deep-water deposit) reservoirs Irish Exploration: Discoveries offshore Ireland Slyne and Erris Basins: The Corrib Field Porcupine Basin: The 2013 Dunquin well The 2017 Druid/Drombeg well 60 60 GEOL 40310 Lecture A5 30