Enhanced oil recovery using CO 2 The North

Enhanced oil recovery using CO 2 The North Sea, an Opportunity? Jon Gluyas Durham Energy Institute, UK Carbon Capture & Storage, Geological Society of London - 15 th September 2010 -

Outline • • CO 2 -EOR – a long history UK oil reserves UKCS – the EOR prize UK industrial CO 2 production Project timing Costing the earth & saving the planet The CO 2 -EOR heritage

CO 2 -EOR – A Long History • Initiated 1970 s in response to oil crisis • Texas at forefront of technology & leads the way today • Permian Basin in NW Texas is the primary injection area • 1000 s km 32” pipeline & associated infrastructure developed • Natural & anthropogenic CO 2 sources used

CO 2 -EOR – Technology • Water Alternating Gas (WAG) – CO 2 injected to swell oil and increase fluidity – H 2 O injection to displace oil to production wells • Gravity Stable Gas Injection (GSGI) – CO 2 injected at field crest – Stabilising pressure and promoting gravity drainage • Miscible flood – critical CO 2 dissolved in oil – swelling oil, viscosity reduced surface tension reduced • Immiscible CO 2 displacement – Partial dissolution in oil may reduce viscosity substantially

Schematic WAG http: //www. netl. doe. gov/scngo/Petroleum/publications/eordrawings/eordraw. html

How much additional recovery? • West Texas 4 -12% of STOIIP (observed) – 60+ projects (~100 world wide) • US DOE 7 -14% of STOIIP (calculated) • Institute for Energy (Netherlands) 9 -18% STOIIP of UK, Norwegian & Danish fields (calculated)

How much CO 2 is used? • 0. 1 to 0. 45 pore volumes injected • Typically 1 (net*) tonne of CO 2 injected delivers 2. 5 to 5 bbl oil (average 3 bbl) • Tapered WAG (decreasing CO 2 volumes) most effective *Net = total injected - recycled

UK Oil Fields From Gluyas & Hichens, 2003 Viking Graben Moray Firth & Central N Sea

UK Offshore Oil Reserve Proven Cumulative Oil Production in millions tonnes (bnbbl) 3315 (24. 9) Estimated Ultimate recovery in millions tonnes (bnbbl) 3723 (27. 9) Probable P+P Possible Maximum 361 (2. 7) 4048 (30. 4) 360 (2. 7) 4444 (33. 3) https: //www. og. decc. gov. uk/information/bb_updates/chapters/Table 4_3. htm

UKCS Recovery Factors ~45% • High End - Piper – recovery factor >70% • Low End - Lyell – recovery factor ~5% Jayasekera & Goodyear SPE 75171

UKCS & West Texas Oil Fields UKCS West Texas • • • Sandstones Most > 2. 7 km deep Most > 90ºC Light oil ~35 -40 API Typically high quality (permeability – 100 s m. D) • Line drive water floods for secondary recovery • Low well density 2 nd Development Board Meeting Sandstones & dolomites 1. 2 to 1. 8 km deep 15 -60ºC Light oil 30 -42 API Typically low quality (permeability 4 -16 m. D) • Pattern floods l • High well density

UKCS vs West Texas • West Texas – incremental oil recovery 4 -12% of STOIIP • CO 2 is expected to be miscible (or nearly so) with current conditions in the UKCS oil reservoirs • UKCS fields more permeable and at higher temperature than those in West Texas – both factors may favour the North Sea From Goodyear et al, IEA EOR Caracas 2002

UKCS – The Prize • Assuming UKCS: – Reserve of 30, 000 mmbbl – STOIIP 30, 000/0. 45 = 67, 000 mmbbl • From West Texas 4 -12% additional recovery of STOIIP – Yields 2, 700 – 8, 000 mmbbl technical reserves – Requiring ~1 t CO 2 per 3 bbl* • For ~3, 000 mmbbl, ~1, 000 Mt CO 2 required *range 2. 5 to 5 bbl/tonne

UK Industrial CO 2 production 2007 • Scotland 19 mm tonnes • North East 21 mm tonnes • Yorkshire 27 mm tonnes & Humberside UK oil province 100 km http: //www. decc. gov. uk/en/content/cms/statistics/climate_change. aspx

Supply & Demand • Assuming all industrial CO 2 from the eastern UK could be available for CO 2 EOR yields 60 -70 mm tonnes per annum • Over a 15 -25 year period (ie typical CO 2 EOR project length) this would use 1 billion tonnes CO 2 …. the quantity required to optimise CO 2 -EOR in the North Sea

Are UK Oil Fields Ready For CO 2 -EOR? Arbroath Maureen Claymore Ninian

The Time is Right (but don’t wait) UKCS Shrinking Infrastructure Jayasekera & Goodyear SPE 75171

UK Security of Supply Shortfall in 2010 ~15 mm tonnes Equivalent to ~300, 000 bopd Equivalent to Initiating ~1/3 potential CO 2 EOR projects DECC publication 2008

Costing the Earth? • For the North Sea – There is no CO 2 infrastructure – There is no ‘ready’ source of CO 2 – The first project will be an enormous commitment • But in 2003 – – – Wo. S to Magnus pipeline laid ~200 miles long CH 4 for WAG 50 mmbbl additional reserves 3+ years extra field life

Saving the Planet • 1 bbl of oil contains ≡ 0. 42 t CO 2 after combustion • 1 bbl produced by CO 2 -EOR requires between 0. 4 and 0. 2 t CO 2 • At best – the process is carbon neutral • At worst – the process is halving emissions

CO 2 -EOR Heritage • The CO 2 production from eastern UK could ‘power’ CO 2 -EOR in the North Sea for 10 -15 years per project, over ~30 year period • It could deliver: – Improved security of oil supply – Infrastructure usable for carbon capture – Increased tax revenues over current projections Deep aquifer storage area