Browsing by Author "Brink, F"
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- ItemCore characterisation and predicted CO2 reactivity of sandstones and mudstones from an Australian oil field(Elsevier, 2022-02-01) Pearce, JK; Brink, F; Dawson, GW; Poitras, J; Southam, G; Paterson, DJ; Wolhuter, A; Underschultz, JRCO2 geological storage has been proposed as one method to mitigate climate change. Storage of CO2 in depleted oil or gas fields is one option, potentially following enhanced recovery. Understanding the potential impacts of CO2 water rock reactions is an important aspect of storage feasibility studies. Drill core samples of sandstones and mudstones from the Jurassic Moonie oil field, Australia, were characterised. In the Precipice Sandstone reservoir samples pore throats had broad size distributions, with mercury intrusion porosities 6.2 to 14.6%. Evergreen Formation samples were more variable with 1.2 to 16.1% porosity. Porosities measured by QEMSCAN were in reasonable agreement at 8.6 to 15.3% for Precipice Sandstones, and 0.6 to 21.5 for the Evergreen Formation. Sandstones had larger pore throat sizes and lower threshold pressures indicative of good reservoir rocks. Calcite cemented sandstones had truncated pore throat distributions, and the coal and clay rich mudstones had pore throats <0.1 μm with higher threshold pressures likely to seal or baffle CO2. Quartz grains were naturally fractured, with silica, apatite, rutile, calcite, and siderite cements filling porosity in some samples. Feldspars had been weathered producing secondary porosity but also resulting in kaolinite and illite filling intergranular porosity. Pyrite and barite were mainly associated with coals. Synchrotron X-ray fluorescence mapping showed Sr was mainly hosted in calcite cement, apatite and barite; with Rb in both plagioclase and K-feldspars. Calcite mainly hosted Mn; while Zn and Cu were mainly in sulphides. Sulphide minerals in coal also hosted As in one core. Kinetic geochemical CO2-water-rock modelling using the characterisation data over 30 or 1000 years indicated reaction of carbonate minerals where present, and alteration of mainly plagioclase, K-feldspar and chlorite. Net precipitation of ankerite, calcite or siderite mineral trapped 0.23 to 1.28 kg/m3 of CO2 after 1000 years in the different rock packages and was highest in Evergreen Formation rocks. The predicted pH was in the range 5.0 to 5.4 after 1000 years, or higher at 5.2 to 7.1 in lower CO2 fugacity models. Sandstone reactivity was overall low over 30 years indicating a low likelihood of reservoir scaling which would be favourable, with mineral trapping likely in the overlying Evergreen Formation. © 2021 Elsevier B.V.
- ItemHighly efficient visible light catalysts driven by Ti3+-VO-2Ti4+-N3− defect clusters(Wiley, 2018-10-13) Sun, QB; Zhang, SY; Cortie, DL; Langley, J; Cox, N; Frankcombe, TJ; Gao, J; Chen, H; Withers, RL; Kremer, F; Yu, DH; Brink, F; Shi, WS; Liu, YLocal defect structures play significant roles on material properties, but they are seriously neglected in the design, synthesis, and development of highly efficient TiO2-based visible light catalysts (VLCs). Here, we take anatase TiO2 nanocrystals that contain (Ti3+, N3−) ions and have the complicated chemical formula of (Ti1-x4+Tix3+)(O2-2-y-zNy3-□z) as an example, and point out that the formation of Ti3+-VO-2Ti4+-N3− local defect clusters is a key missing step for significantly enhancing VLC properties of host TiO2 nanocrystals. Experimental and theoretical investigations also demonstrate the emergent behaviors of these intentionally introduced defect clusters for developing highly efficient VLCs. This research thus not only provides highly efficient visible light catalysts for various practical applications but also addresses the significance of local defect structures on modifying material properties. © 2019 Wiley-VCH Verlag GmbH & Co.
- ItemHighly efficient visible light catalysts driven by Ti3+‐VO‐2Ti4+‐N3− defect clusters(Wiley, 2018-10-13) Sun, QB; Zhang, SY; Cortie, DL; Langley, J; Cox, N; Frankcombe, TJ; Gao, J; Chen, H; Withers, RL; Kremer, F; Yu, DH; Brink, F; Shi, WS; Liu, YLocal defect structures play significant roles on material properties, but they are seriously neglected in the design, synthesis, and development of highly efficient TiO2‐based visible light catalysts (VLCs). Here, we take anatase TiO2 nanocrystals that contain (Ti3+, N3−) ions and have the complicated chemical formula of ()(□z) as an example, and point out that the formation of Ti3+‐VO‐2Ti4+‐N3− local defect clusters is a key missing step for significantly enhancing VLC properties of host TiO2 nanocrystals. Experimental and theoretical investigations also demonstrate the emergent behaviors of these intentionally introduced defect clusters for developing highly efficient VLCs. This research thus not only provides highly efficient visible light catalysts for various practical applications but also addresses the significance of local defect structures on modifying material properties. © 1999-2024 John Wiley & Sons, Inc or related companies.
- ItemImpure CO2 storage reactions of sandstone, mudstone and carbonate cemented cores: xxperimental CO2 SO2 NOX O2 reaction metal mobilisation and fate(Elsevier, 2023-09-01) Pearce, JK; Dawson, GW; Brink, F; Southam, G; Paterson, DJ; Hall, N; Heath, R; Greer, D; Kirste, D; Golding, SDCO2 geological storage can be part of the solution to reduce carbon emissions to the atmosphere. An understanding of the geochemical processes occurring during CO2 storage is needed to reduce risk. Drill cores from a low salinity reservoir site proposed for CO2 storage, and the overlying and underlying formations, were characterised for minerals by QEMSCAN, total metals and porosity. Elements including Li, Ba, Sr, K, Mg, V, Zn, REE, Fe, Pb, P, and S were relatively elevated in the Moolayember Formation underlying the reservoir. Synchrotron XFM showed the main host of Mn was siderite, with Rb in K-feldspar, Zn and Cu in sphalerite and chalcopyrite, and As in pyrite in coal pores associated with coal laminations. Drill cores are reacted at reservoir conditions with synthetic formation water and an impure CO2 stream composition of CO2-SOx-NOx-O2 expected to be injected at the site. Elements released were dependant on mineral content, with quartz rich reservoir, lower Precipice Sandstone core reactions resulting in dissolution of trace carbonates, alteration of sulphides and monazite, and variable elevated dissolved Pb, and U. Dissolved Co, Ni, Ca, Zn, Li, Rb, and U were released at relatively elevated concentrations from the mudstone. For carbonate cemented upper Precipice Sandstone or Moolayember Formation core strong dissolution of calcite and ankerite, with corrosion of siderite, Fe-rich chlorite, and sulphides or monazite were observed after reaction. Dissolved elements including Ca, Mg, Mn, Sr, and Ba increased in experiments from the reaction of calcite, siderite, and ankerite. Generally dissolved Fe, Pb, Cr, Cu, Co etc. increased from dissolution, and subsequently decreased in concentration with adsorption and precipitation processes. The fast mobilisation of elements including Fe and Pb are consistent with the release of metals from carbonate dissolution and desorption. The presence of O2 and NOX in the gas stream results in Fe-(oxyhydr)oxide precipitation especially where Fe has been rapidly mobilised from dissolution of siderite and Fe-chlorite. This acts as a sink for Fe and provides new adsorption sites for sequestering a proportion of the trace metals. These processes are applicable to other CO2 storage sites and potential leakage indicators in overlying drinking water aquifers. The findings are also more broadly applicable to subsurface energy storage such as compressed air renewable energy storage, CO2 enhanced recovery, geothermal, natural gas or hydrogen storage. © 2023 The Authors. Published by Elsevier B.V. - Open Access CC-BY.
- ItemPotassium silicate alteration in porphyry copper‑gold deposits: a case study at the giant maar-diatreme hosted Grasberg deposit, Indonesia(Elsevier, 2022-12) Henley, RW; Mernagh, TP; Leys, C; Troitzsch, U; Bevitt, JJ; Brink, F; Gardner, J; Knuefing, L; Wheeler, J; Limaye, A; Turner, M; Zhang, YPotassium silicate alteration is a hallmark of the porphyry copper deposits that supply two thirds of the world's annual copper demand. These deposits formed in the cores of calc-alkaline to alkaline volcanic systems from the flux of magmatic gas that transported copper and other metals from source to the surface. The giant 3.2 Ma Grasberg Cu[sbnd]Au deposit formed within a maar-diatreme complex following a resurgence in magmatism. The defined resources of this deposit occur from a few hundred metres depth to 1.7 km below the paleosurface which, uniquely in this deposit, is partially preserved as a section of maar tuffs. Potassium silicate alteration has commonly been interpreted as being the result of the addition of potassium to the porphyry copper host rocks via pervasive interaction with a large volume of a potassium-rich brine that is commonly presumed to be of magmatic origin. However, the data reported here show that alteration at the deposit scale is essentially isochemical with respect to the major rock-forming components and that only sulphur and the economic metals (Cu, Mo, Au, etc.) are added by flux of reactive magmatic gas containing SO2 and HCl from source intrusions at depth. Silicate solubilities are very low so that only a minor fraction of the total alkalis in the host rock are extracted by alteration reactions and then discharged at the paleo-surface. Reaction of the magmatic gas phase with plagioclase results in the coupled deposition of anhydrite (CaSO4) and disproportionation of SO2 to release H2S. The in-situ release of H2S immediately scavenges Cu and other chalcophile metals from the continuing magmatic gas flux to form the Cu-, Fe- and other sulphides that, in sufficient concentration, make up the economic reserve available to mining. The sequestration of Ca into anhydrite, along with deposition of silica into early quartz veins, increases the concentration of the other major components (K2O, Na2O, MgO, etc) in the remaining silicate assemblage within the porous host rock. The result is the development of intermingled potassium-enriched silicate and sulphur-rich (anhydrite-sulphide) sub-assemblages that constitute the mineralised phyllic or potassic alteration zones. These crystallise according to their pressure and depth into alteration assemblages dominated by potassic phyllosilicates, quartz and pyrite in the phyllic alteration zone, and alkali feldspar and phlogopitic-biotite plus minor andalusite and corundum in the central potassic zone. Dissolution and recrystallisation of primary magmatic biotite in the host rock releases K as well as Fe, the latter (along with amphibole and feldspar) providing iron for the formation of chalcopyrite, bornite and pyrite. The in-situ release of H2S through anhydrite formation, immediately scavenges Cu and other chalcophile metals from the continuing magmatic gas flux to form the Cu[sbnd]Fe[sbnd] sulphides that, in sufficient concentration, make up the economic reserve available to mining. Understanding of the alteration processes during porphyry copper formation also provides insights into gas-solid reactions processes inside active magmatic arc volcanoes but the magnitude of copper mineralisation is dependent on the original metal content of the source of the magmatic gas phase. © 2022 Elsevier B.V.
- ItemPredicted CO2 water rock reactions in naturally altered CO2 storage reservoir sandstones, with interbedded cemented and coaly mudstone seals(Elsevier, 2022-03-15) Pearce, JK; Dawson, GW; Golding, SD; Southam, G; Paterson, DJ; Brink, F; Underschultz, JRGeological storage of CO2 captured from industrial processes such as coal combustion or from direct air capture is part of the transition to low emissions. The Jurassic Precipice Sandstone of the southern Surat Basin, Queensland, Australia, is undergoing feasibility studies for industrial scale CO2 geological storage, however regional data has so far been lacking. Precipice Sandstone reservoir drill core samples from the Southwood 1 and Tipton 153 wells in the southern Surat Basin include favourably quartz rich sandstone regions with quartz grain fracturing. A mudstone layer is also present in the reservoir. The overlying lower section of the Evergreen Formation seals consist of clay rich sandstones, interbedded mudstones, coal layers, Fe-Mg-Mn siderite, and Mg-calcite cemented sandstones. K-feldspars are weathered creating localised secondary porosity and pore filling kaolinite and illite. Layers of coal, pore filling cements, and framework grain compaction introduce vertical heterogeneity. Heavy minerals including pyrite, mixed composition sulphides, and barite are associated with disseminated coals in mudstones. Precipice Sandstone mercury intrusion porosities (MIP) ranged from 9 to 22% with favourably low reservoir injection threshold pressures, and the QEMSCAN measured open porosity between 2 and 22%. Evergreen Formation seal porosities were 7.5 to 16% by MIP or 1 to 19% by QEMSCAN, with the smallest pore throat distribution associated with the low permeability coal rich mudstone. Synchrotron XFM shows Rb mainly hosted in K-feldspars and muscovite, with metals including Mn mainly hosted in siderite. Zn and As are present in sulphides; and calcite and apatite cements mainly hosted Sr. Twenty kinetic geochemical CO2-water-rock models were run for 30 and 1000 years with Geochemist Workbench, with calcite and siderite initially dissolving. In the Precipice Sandstone reservoir variable alteration of carbonates, feldspars and chlorite to kaolinite, silica, siderite and smectite were predicted with the pH remaining below 5.5. CO2 was mineral trapped through alteration of chlorite to siderite in three of the four cases, with −0.02 to 1.43 kg/m3 CO2 trapped after 1000 years. In the calcite and siderite cemented Evergreen Formation seal, plagioclase conversion to ankerite trapped the most CO2 with 2.6 kg/m3 trapped after 1000 years. The Precipice Sandstone in both wells appears to be generally suitable as a storage reservoir, with mineral trapping predicted to mainly occur in the overlying lower Evergreen Formation and in interbedded mudstones. Heterogeneity in interbedded sandstone, mudstone, and coal layers are likely to act as baffles to CO2 and encourage mineral trapping. Quartz grain fractures may influence preferential migration pathways in the reservoir but this would need future experimental investigation. Experimental CO2 water rock reactions to understand porosity and permeability changes were out of scope here but are recommended in future validation, along with investigating the potential for CO2 adsorption trapping in coal and mudstone layers. © 2022 Elsevier B.V. All rights reserved.