GEOL40310_LectureD2_Sequestration2_2023.pdf

Geol 40310 Fossil Fuels and Carbon Capture & Storage (CCS) Lecture D2: CO2 sequestration for Enhanced Oil Recovery (EOR) Autumn 2023 T. Manzocchi, UCD 1 1 Lecture D2: CO2 sequestration for Enhanced Oil Recovery (EOR) - Miscible CO2 flooding - Sweep efficiency and pre-scale recovery. - Permian Bas...

Geol 40310 Fossil Fuels and Carbon Capture & Storage (CCS) Lecture D2: CO2 sequestration for Enhanced Oil Recovery (EOR) Autumn 2023 T. Manzocchi, UCD 1 1 Lecture D2: CO2 sequestration for Enhanced Oil Recovery (EOR) - Miscible CO2 flooding - Sweep efficiency and pre-scale recovery. - Permian Basin Examples: - SACROC unit, Denver Unit of Wasson Field. - Natural and anthropogenic CO2 sources - Immiscible CO2 flooding - Great Plains / Weyburn project - CO2 Storage in un-minable coal seams (Coal bed methane production) 2 2 Geol 40310 Lecture D2 1 CO2 storage Options (IPCC Report, 2005): Lecture D1 Ocean Storage • Dissolution type • Lake type Mineral carbonation • Subsurface mineralisation • Surface waste materials, soils Geological storage Lecture D2 • Enhanced Oil Recovery (EOR) • Unminable coal seams • Depleted oil/gas fields • Saline aquifers Lecture D3 3 3 Global CO2 volumes sequestered 1970 - 2022 Million tonnes of CO2 / year operational In construction Dedicated geological storage 1972: Val Verde USA 1996: Sleipner, Norway Enhanced oil recovery Data from Global Status of CCS 2022; Global CCS Institute 4 Geol 40310 Lecture D2 2 Global CO2 storage projects- operational and planned Global Status of CCS 2022; Global CCS Institute 5 Planned CCS Hubs Global Status of CCS 2022; Global CCS Institute 6 Geol 40310 Lecture D2 3 Planned CCS Hubs - Europe 7 Primary, secondary and tertiary recovery: example of Ula field, Norwegian North Sea Primary depletion Secondary Recovery: Waterflooding Tertiary Recovery (EOR): Miscible Gas Inection, foam injection Oil production rate (mbbls/d) Plateau 2 Plateau 1 STOIIP ca. 1 Billion Bbls. 2012 2006 GOR (scf/stb) Start Foam Assisted WAG Extend WAG Scheme First Gas returns Sttart decline Water breakthrough Increased injection rate Start miscible WAG 1996 1986 Gas Injection rate (mmscf/d) Start water injection Watercut (%) Water Injection rate (mbbls/d) Arrested decline Zhang et al. (2013) 8 Geol 40310 Lecture D2 4 Number of EOR projects in operation globally, 1971 -2017 9 Source: IEA: https://www.iea.org/commentaries/whatever-happened-to-enhanced-oil-recovery 9 CO2 EOR: Two very different processes Recovery factor = Microscopic displacement * macroscopic sweep Miscible CO2 EOR: change oil properties to increase pore-scale recovery Immiscible CO2 EOR: change system engery to increase large-scale recovery 10 10 Geol 40310 Lecture D2 5 Laboratory Coreflood studies – miscible solvent Oil saturation (%) • After an initial waterflood, residual oil is left in the largest pores. • An injected solvent sweeps the water-flooded regions, and mixes with the oil. • The solvent/water interfacial tension is lower than the original oil/water one, so the oil-saturated solvent has a higher recovery than the initial oil. Water injection Alternating CO2 / water injection A C B D Pore volumes Injected A. Initial conditions C. During Solvent flood B. After waterflood D. After final waterflood 11 11 Control of Mobility ratio on areal sweep efficiency Stable fronts at low Mobility ratios. Mobility = 0.15 Break-through at 0.8 PV Mobility = 1.0 Break-through at 0.7 PV Viscous fingering at high Mobility ratios. Mobility = 2.4 Break-through at 0.4 PV Mobility = 71 Break-through at 0.1 PV Oil recovery (%) Areal sweep in a quarter- five-point pattern. Curves of different pore volumes of injected gas M = 0.15 M = 1.0 M = 2.4 M = 71 Pore volumes Injected water 𝑀= 𝑘𝑟𝑤 Τ𝜇𝑤 𝑘𝑟𝐶𝑂2Τ𝜇𝐶𝑂2 CO2 has a much lower viscosity than water so the system has an unfavourable (i.e high) mobility ratio of about 20. 12 12 Geol 40310 Lecture D2 6 EOR through Miscible CO2 flooding After initial water-flood: Macroscopic Sweep efficiency: 81% Pore-scale recovery: 54% Recovery factor: 44%. After miscible Solvent flood: Macroscopic Sweep efficiency: 40% Incremental pore-scale recovery: 20% Incremental Recovery factor: 8%. Final Recovery factor: 52%. 13 Source: SPE PetroWiki 13 Minimum Miscibility Pressure: • The pressure at which interfacial tension between the two fluids (e.g. CO2 and oil) is zero, so they are utterly miscible. • Different solvent / hydrocarbon combinations have different MMPs, so choice depends on reservoir conditions as well as solvent costs. • CO2 has a low MMP, making it an attractive option in many cases Source: SPE PetroWiki 14 14 Geol 40310 Lecture D2 7 How much solvent is necessary? Diminishing returns with additional injected volumes. Field results indicate a ca. 10% increase in recovery for 30% HCPV slug Incremental recovery factor (%) • • Slug size (% of hydrocarbon pore volume in place (HPCV)) Source: SPE PetroWiki 15 15 CO2 EOR, USA West Texas Oilfields Weyburn Wasson SACROC Permian Basin 16 16 Geol 40310 Lecture D2 8 Onshore pattern drilling: many thousands of closely-space wells SACROC Wasson Denver Unit 1 mile 17 17 SACROC (Scurry Area Canyon Reef Operators Committee) Unit in west Texas – Miscible CO2 flood Cumulative injection of ca. 1 TCF CO2. (52 million tonnes of CO2) Water-flood sweep efficiency: 74% Miscible flood sweep efficiency: 44% Primary + secondary recovery factor: 57% Incremental CO2 flood recovery factor: 9% 18 SPE: Petrowiki 18 Geol 40310 Lecture D2 9 Denver Unit, Wasson Field – Production history Total recovery factor: 67% (to 2005) Secondary: +30% recovery Primary: 17% recovery 1938 • • • • • • 45 55 Tertiary: +20% recovery 65 STOIIP: 2.1 billion barrels. 20-acre spaced inverted nine-spot water injection pattern reconfigured for miscible CO2 injection. Reservoir depressurised from 3,200 to 2,200 psi to optimise miscibility. Oil production rate decline halted and production rate stabilised for 20 years. WAG (water alternating gas) process with different timings tested in different areas. Final expected cumulative CO2 slug will be 70% of HCPV, with a final water injection phase. 19 19 Denver Unit, Wasson Field – projected CO2 volumes Historic and forecast CO2 injection, production and storage 1980-2120 1 million tonnes of CO2 = ca. 19 Bcf To end 2011: 213 million tonnes CO2 injected 84 million tonnes CO2 produced 123 million tonnes CO2 stored. Expect final storage: 200 million tonnes of CO2 (25% of of the theoretical storage capacity of the Denver Unit) 20 20 Geol 40310 Lecture D2 10 CO2 infracture, Permian Basin. Over 70% of CO2 used in CO2 EOR projects in the USA comes from natural sources Natural CO2 reservoirs Oil reservoirs using CO2 EOR Wasson SACROC Industrial CO2 sources 21 21 McElmo Dome CO2 field Current CO2 production from McElmo Dome: ca. 1 bcf / day (c.f. Corrib field: Plant Capacity is ca. 0.3 bcf/day) Oil and Gas Journal 04/07/2014 22 22 Geol 40310 Lecture D2 11 CO2EOR for CCS Where does the CO2 come from, and who credits its sequestration? CO2 from natural sources: Net CO2 emissions no benefit to carbon intensity of the produced oil CO2 from anthropogenic sources: Net CO2 emissions Captured and stored CO2 can be credited to power sector or oil sector, but not both! • Power-plant operator gets credit for capturing the CO2 and pays the oil company to get rid of it Or: • Oil company buys the CO2 from the power-plant operator and gets credit for sequestering it Approximately carbon-neutral CO2 from bioenergy or direct air capture: potentially carbon neutral or carbon negative. If more CO2 is sequestered than is used by extracting and burning the oil, this is carbon negative McGlade 2019: https://www.iea.org/commentaries/can-co2-eor-really-provide-carbon-negative-oil 23 “Conventional” vs. “Advanced” CO2-EOR Objective is to maximise CO2 sequestration and offset this cost by producing oil, rather then to maximise profit from oil sales. Example for a hypothetical 180 Mbbl STOIIP oilfield: • Advanced CO2-EOR sequesters twice the amount of CO2 / barrel of oil produced compared to Conventional CO2-EOR • Net CO2 emissions (i.e. emissions including those associated with burning the oil) decease with incremental production for Advanced CO2-EOR. • However, despite less overall oil production, Conventional CO2-EOR is more financially rewarding due to fewer CO2-handling costs. • Break-even costs for Advanced CO2-EOR are $22$32 / Tonne of CO2. Benson and Deutch, 2018, Joule2, 1386–1389 US Inflation Reduction act, 2022: Tax credits of $85 per tonne of CO2 permanently stored $60 per tonne of used CO2 (e.g. EOR) if storage can be demonstrated $180 per tonne of DAC CO2 permanently stored $130 per tonne of used CO2 from DAC 24 24 Geol 40310 Lecture D2 12 Plans for carbon neutral oil in the Permian Basin • • • • Occidental Petroleum (Oxy) operate many of the Permian Basin CO2 EOR fields and in 2020 announced its plans to make its operations, and combustion of its product, carbon neutral by 2050. A planned pipeline from the Midwest would replace natural CO2 sources with CO2 captured from biofuel plants, sequestering up to 40 million tonnes of CO2 year. Installation of DAC plants will scale-up of their CO2 EOR operations while sequestering more CO2: 0.5 million tonnes DAC plant expected to be operational by mid-2025 Proposed Midwest CO2 Superhighway McElmo Dome The first rendering of what is to be the world’s largest direct-aircapture-plant in the Permian Basin. The facility is expected to capture up to 1 million metric tons of CO2 annually for enhanced oil recovery operations in Texas. Source: Occidental Petroleum Journal of Petroleum Technology, Nov 2020 25 Primary, secondary and tertiary recovery Primary Recovery Use the reservoir’s own energy Deletion drive Solution gas Drive Gas Cap Drive Water Drive Compaction Drive Secondary Recovery (Improved oil Recovery) Increase the reservoir’s energy Water Injection. Gas Injection. Immiscible WAG (water alternating gas) Improve Sweep and Drainage efficiency Waterflood design. Infill drilling. Horizontal wells. Enhanced Oil Recovery (Tertiary Recovery) Reduce Hydrocarbon viscosity Thermal methods Improve porescale efficiency Miscible flooding (solvents, miscible WAG) Chemical flooding Foams, surfactants 26 26 Geol 40310 Lecture D2 13 Immiscible WAG in etched Glass micro-models WAG: Water Alternating Gas injection inlet outlet Initial water flood Gas flood 1 water flood 1 Gas flood 2 water flood 2 Gas flood 3 oil Water gas van Dijke et al. (2006) 27 Weyburn unit oil production, 1955-2018 Water flood In-fill drilling Immiscible WAG • Ca. 2 billion barrels Oil-in-place, 35% recovery factor to 2018 • Field is sequestering 2 million tonnes of CO2 a year, towards a total storage capacity of ca. 55 Mt CO2 28 28 Geol 40310 Lecture D2 14 Weyburn CO2 EOR Field • • 1.9 billion barrels in place, 524 million barrels recovered to 2000. CO2 injection expected to produce another 200 million barrels. CO2 receiving terminal CO2 piped from two sources: Boundary Dam: post combustion CO2 capture coal-fired power plant: Great Plains Synfuels Plant – Coal Gassification. 29 29 Weyburn Field: Recovery by Water injection and immiscible water-alternating-gas injection (WAG) Well-ordered strataboud fracture system: Fractured, vuggy limestone (porosity 1520%), overlain by chalky dolomite (20-35% porosity) – most of the oil is in the matrix. Secondary recovery by waterflooding – spontaneous water imbibition into the matrix Tertiary recovery by gas-flooding – gravity drainage of unswept oil 30 Narr et al (2005) 30 Geol 40310 Lecture D2 15 CO2 sequestration in un-minable coal seams Sorption capacity • Methane is fixed on coal surface within the cleats (tiny fractures). • In coal-bed methane production, dewatering reduces pressure and releases this methane as it loses sorption at lower pressure. • The sorption capacity of CO2 is much greater than of methane, therefore injecting CO2 may release additional methane, and sequester the CO2. Curves for different coals 31 Coal-bed methane resources and production Mastalerz (2014) 32 Geol 40310 Lecture D2 16 Enhanced coal-bed methane CO2 storage projects This is a total of ca. 50 kt CO2 /year, comparable to the volume sequestered in the Iceland Hellisheidi geothermal project. Ajayi et al. 2019. Petroleum Science16:1028–1063 33 CO2 storage Options (IPCC Report, 2005): Lecture D1 Ocean Storage • Dissolution type • Lake type Mineral carbonation • Subsurface mineralisation • Surface waste materials, soils Geological storage Lecture D2 • Enhanced Oil Recovery (EOR) • Unminable coal seams • Depleted oil/gas fields • Saline aquifers Lecture D3 34 34 Geol 40310 Lecture D2 17