The supporting data for C. Harris et al., 2021, 'The impact of heterogeneity on the capillary trapping of CO2 in the Captain Sandstone', International Journal of Greenhouse Gas Control. We supply experimental and numerical simulation data used in the paper. The supplied codes reproduce each figure. The codes are split into 2 folders, descriptions of each of the folders are given below: 0 - README. This contains detailed instructions on using the supplied files. 1 - Main simulations. This contains the code to produce the main CMG (Computer Modelling Group) simulations outlined in the paper, with various input variable files. 2 - Other figures. This contains the code to produce other figures within the paper which do not rely on numerical simulations, including the experimental data.

UKCCSRC Flexible Funding 2020. The experimental data was collected on a 1-inch bore gas-liquid two-phase CO2 flow rig in real time. The first column of the table is the time stamp. The second to 19th columns are the mass flowrates, temperatures, densities and tube frequencies from Coriolis flowmeters installed on the gas phase section, liquid phase section, horizontal test section and vertical test section, respectively. The last column of the datafile is the reading from the differential pressure (DP) transducer installed across the Coriolis flowmeter on the horizontal test section. UKCCSRC Flexible Funding 2020: Monitoring of CO2 flow under CCS conditions through multi-modal sensing and machine learning.

This dataset contains carbon dioxide concentration measurements from the British Antarctic Survey's Halley Research Station in Antarctica. The Picarro G2301 analyser was used for the measurement of carbon dioxide and located at the Clean Air Sector Laboratory (CASLab). Data times were averaged from the 1 minute data to provide hourly data sets. The UK participation of Southern OceaN optimal Approach To Assess the carbon state, variability and climatic drivers (SONATA) was funded by the Natural Environment Research Council (NERC, grant: NE/P021360/1).

This dataset contains atmospheric carbon dioxide, oxygen and atmospheric potential oxygen data from the Cap San Lorenzo container ship. A Li-6252 CO2 analyser and Oxzilla II O2 analyser was used for measurement. The UK participation of Southern OceaN optimal Approach To Assess the carbon state, variability and climatic drivers (SONATA) was funded by the Natural Environment Research Council (NERC, grant: NE/P021360/1).

This dataset comprises ECLIPSE input decks for a 3D reservoir simulation of the CO2 plume at the Sleipner CO2 injection site. This whole reservoir model is an attempt to history match the growth of the plume observed on seismic data. A seismic velocity and density model derived from the 3D reservoir simulation is also included, together with a series of Seismic Unix scripts to create a synthetic seismic section through the Sleipner reservoir model, for comparison with released time-lapse seismic data.

UKCCSRC Flexible Funding 2020. Experimental data are the acoustic emission (AE) signals collected with three AE sensors when CO2 leak from a CO2 storage cylinder under different pressures. '5MPa_20kgh-1' means the data was collected when the pressure was 5MPa and the leakage rate was 20 kg/h. The sampling frequency of AE signals is 3MHz. UKCCSRC Flexible Funding 2020: Monitoring of CO2 flow under CCS conditions through multi-modal sensing and machine learning.

This dataset contains atmospheric carbon dioxide and methane measurements taken from Bachok Marine Research Station, Malaysia using Los Gatos Research (LGR) Fast Greenhouse Gas Analyser (FGGA) from 2015 to present. LGR FGGA measures trace concentrations of methane (CH4), carbon dioxide (CO2) and water vapor (H2O) simultaneously in flowing gaseous samples (usually air) at rates up to ≥10 Hz. Backok Research Station is located on the east coast of Malaysia, within 100 m of the waters' edge of the South China Sea. This facility is part of the Institute of Ocean and Earth Sciences (IOES) at the University of Malaya (UM). An atmospheric observation tower has been built on the windward side of the main building, for the specific purpose of studying long range transported pollution, air sea exchange, and coastal meteorology. The UK participation of the Methane Observations and Yearly Assessments (MOYA) project was funded by the Natural Environment Research Council (NERC, grant: NE/N015584/1).

This dataset gathers the data collected during a brine:CO2 flow-through experiments conducted on three sandstones with similar mineralogical compositions (major minerals) but different porosity, clay-size fraction and clay mineralogy. The aim was to study the effect of such heterogeneities on interpretation of geophysical data. Geophysical and transport data were collected before, during and after exposing each sample to CO2, and analysed with basic petrophysical properties. The tests were conducted in the high-pressure, room-temperature (20°C) experimental setup for multi-flow-through tests in the Rock Physics Laboratory at the National Oceanography Centre, Southampton (NOCS), during 2022, as part of the OASIS, EHMPRES and FOCUS projects with funding from the Research Council of Norway (RCN grant no. 280472 - OASIS) and the Natural Environment Research Council (NERC grants NE/X003248/1 - FAPESP-EHMPRES, and NE/X006271/1 - FOCUS). To simulate the specific effective stress conditions of the target CO2 storage reservoir in Aurora (Aker et al., 2021), northern North Sea, the confining and pore pressure conditions of the reservoir were accommodated to our lab temperature conditions. We measured ultrasonic P- and S-wave velocities and attenuations, axial strains and electrical resistivity for an increasing CO2 saturation. The degree of brine saturation was inferred from the electrical resistivity using the modified Archie’s empirical relationship to account for the contribution of clay minerals, based on the Waxman–Smits–Juhasz model (see further details in, e.g., Falcon-Suarez et al. (2021)). We refer to Falcon-Suarez et al. (2020) for further information about the experimental rig and the CO2 injection protocol.

Isotope tracing data for 14C, 15N and 33P tracing between plants and symbiotic fungi in Lycopdiella inundata, Anthoceros and Phaeoceros sp. and Lunularia cruciata. All plants tested and traced in atmospheric CO2 conditions of 440 ppm [CO2] and 800 ppm [CO2]. Datasets includes total mass of plants and soils, Bq in each component of experimental systems and values in Bq and mg where appropriate.

During the drilling of an exploration well in the 1960s, an underground blowout occurred near Sleen, The Netherlands. During approximately 25 months, near-continuous leakage of large amounts of natural gas was released into the subsurface. After the blowout, the local drinking water production company installed a network of groundwater monitoring wells to monitor for possible adverse effects on groundwater quality at the blowout site. Today, more than 50 years after the blowout, the groundwater is still impaired. Data has been correlated with previously published data by Schout et al. (2018) covering description of geology and well depths. During two fieldtrips (November 2019 & October 2020) water samples were collected from several wells covering: - Bulk gas compositions (methane, ethane, propane, oxygen, nitrogen, CO2, Argon). Bulk isotope compositions of methane (δ13C & δH), carbon dioxide (δ13C) and nitrogen (δ15N). - Methane clumped isotope compositions (ΔCD & ΔDD). - Inorganic parameters (hydrocarbons, anions, cations, DOC, alkalinity, nitrate and ammonium). The dataset was created within SECURe project (Subsurface Evaluation of CCS and Unconventional Risks) - https://www.securegeoenergy.eu/. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 764531.