These files contain Electric Resistivity Ground Imaging (ERGI) data measured using a Tigre 128 electric resistivity system with 64 electrodes in a roll-along survey mode. The electrodes were spaced 5 m apart and used in a Wenner a array configuration. The format of the file names is as follows: The two digits following B (18 or 20) is a label indicating the measurement site The digit following the T (1, 2 or 3) is the measurement transect number The next six digits, following the underscore, are the measurement date (ddmmyy) The next two digits, following the second underscore, are the survey number (measurements were repeated multiple times) The files are in tab delimited ascii text format, with three columns of data: Column 1 contains the distance measured across the survey transect Column 2 contains the a-spacing (the distance between adjacent electrode pairs) in m Column 3 contains the measured apparent resistivity value in Ohm m
EPSRC project EP/K035878/1 - Report summarising scientific findings from Work Packages 1 to 4 of the DiSECCS project. These include advanced seismic methods for assessing pressure changes and fluid flow processes in a reservoir rock, experimental rock physics and public perceptions for CCS and analogue activities.
This dataset contains VASP runs performed on ARCHER to calculate the electrical and thermal conductivities of pure iron and iron alloys at Earth's core conditions using density functional theory with the Kubo-Greenwood formulation. Data are available for both the solid and the liquid phase characterising the inner and outer core respectively. Also included in the dataset the runs for computing the lattice contribution to the electrical resistivity of magnetic bcc iron at ambient pressure and two low temperatures and for computing the melting curve of fcc nickel. These data were also used for the modelling of the geodynamo and the thermal history of the Earth, to calculate the transport properties for silicon-oxygen-iron mixtures and to confirm the saturation of electrical resistivity of solid iron at Earth’s core conditions. The results from this dataset showed that both conductivities are much larger than previously thought with important implications for the geodynamo and the thermal history of the Earth, benefitting the geodynamo community. The results of our research have been recently confirmed by new experimental results obtained at Earth's core conditions. Further details can be found in Alfè et al. (2012); Pozzo et al. (2012, 2013a, 2013b, 2014, 2016); Gubbins et al. (2015); Davies et al. (2015). NERC Grant is NE/H02462X/1.
Report summarising the contents of the seismic analysis toolbox produced during the DiSECCS project. The toolbox comprises an online library of seismic software developed and utilised in the project, and presented in a form that other practitioners can utilise and tailor to their own specific needs. The toolbox include software for the measurement and characterisation of thin CO2 layers by spectral and attenuation analysis, fracture characterisation via wavelet coda analysis, novel rock physics algorithms and a summary of new laboratory analyses.
The use of synthetic samples for rock physics experiments in the lab is a common practice for reservoir characterization and reservoir studies. This dataset gather ultrasonic P- and S-wave velocities and attenuations, electrical resistivity, axial and radial strains, permeability and mineralogical composition, of two synthetic and two natural sandstones, measured at variable realistic reservoir conditions of stress. The data were collected during an original study which aimed to assess the extent to which the measured properties between synthetic and natural sandstones are comparable. The work was accepted for publication in Geophysical Prospecting on the 01/10/2018, which can be accessed following the link: https://doi.org/10.1111/1365-2478.12699 Falcon-Suarez, I.H., Amalokwu, K., Robert, K., North, L., Best, A.I., Delgado-Martin, J., Callow, B., Sahoo, S.K. (accepted). Comparison of stress dependent geophysical, hydraulic and mechanical properties of synthetic and natural sandstones for reservoir characterisation and monitoring studies. Geophysical Prospecting
Here we present the dataset collected during a CO2 flow-through test using a synthetic sandstone of high porosity and permeability, originally saturated with high salinity brine, performed under realistic shallow reservoir conditions stress. During the test, we collect geophysical data (elastic and electrical properties) which record petrophysical variations in the rock related to the precipitation of salt, induced by a continuous CO2 flow through the sample.
The spreadsheet gathers the data collected during an experiment conducted on a Utsira Sand formation core sample to complements and constrains existing geophysical monitoring surveys at Sleipner and, more generally, improves the understanding of shallow weakly-cemented sand reservoirs. The tests were conducted in the rock physics laboratory at the National Oceanography Centre, Southampton, during 2016, as part of the DiSECCS project with funding from the United Kingdom’s Engineering and Physical Sciences Research Council (EPSRC grant EP/K035878/1) and the Natural Environment Research Council (NERC). The experiment was a steady state brine-CO2 flow-through test to simultaneously evaluate ultrasonic waves, electrical resistivity (converted into pore fluid distribution) and mechanical indicators during CO2 geosequestration in shallow weakly-cemented reservoirs. The confining and pore pressure conditions were similar to those estimated for Sleipner (North Sea – like storage reservoirs), but simulating inflation/depletion cyclic scenarios for increasing brine:CO2 fractional flow rates. The data include primary ultrasonic wave velocities and attenuation factors, axial and radial strains, and electrical resistivity. Also, we provide a velocity-saturation relationship of practical importance to CO2 plume monitoring, obtained from the inversion of ultrasonic velocity and attenuation data and extrapolation of results to field-scale seismic-frequencies using a new rock physics theory. The dataset is linked to this publication: http://www.sciencedirect.com/science/article/pii/S1750583617306370.
EPSRC project EP/K035878/1 - DiSECCS research has focussed on developing advanced seismic monitoring tools and combining these with social science research to identify key factors in establishing trust and confidence in the storage system.This report presents insights into and recommendations for the monitoring systems and protocols required to maintain the integrity of storage reservoirs suitable for large-scale CO2 storage and for obtaining a social licence to operate a CCS project.
Physical properties of four serpentinite and four gabbro samples acquired respectively at the Southern Wall (IODP leg 357) and at the Central Dome (IODP leg 304-305) of the Atlantis Massif have been measured and analysed in the frame of a NERC UK-IODP moratorium research. The physical property measurements included simultaneous ultra-sonic wave velocities (compressional and shear wave velocities), attenuation, electrical resistivity and permeability under increasing and decreasing effective pressure ranging between 5 and 45 Mpa. Measurements were carried out using the experimental physical property measurement rig of the rock Physics laboratory of the National Oceanography Centre, Southampton, UK. The porosity and the density of the samples were estimated using their wet dry weight difference and the volume of the samples, under atmospheric pressure and room temperature. The aim of this research project was to learn about the physical properties of oceanic lower crustal and upper-mantle rocks and to find a geophysical method that would allow to distinguish between these rocks, remotely. The dataset has been acquired and interpreted by a science party including researchers from the University of Southampton and the National Oceanography Centre. The ultrasonic wave velocities, attenuation and the electrical resistivity for each sample and for each effective pressure (increasing from 5 to 45 with an interval of 10 MPa and decreasing from 45 to 5 with an interval of 20 MPa) are reported in this dataset. Permeability measurements could have been carried out only on 6 samples for which the permeability was high enough to be measured with the experimental rig.
The dataset is a Soil Corrosivity Map for the U.K. based on the BGS DIGMapGB-PLUS Map. The creation of this dataset involves scoring the Soil Parent Material types for five different attributes that contribute towards the corrosion of underground assets. These are (i) high or low soil pH, (ii) general soil moisture, (iii) the likelihood that soil saturated and undergo periods of anaerobic conditions, (iv) the presence of sulphides and sulphates and (v) the resistivity of the soil parent material. The scoring of each of these parameters was undertaken based on the Cast Iron Pipe Association (CIPA) (now the Ductile Iron Pipe Research Association, DIPRA) rating system. By combining the scores of each parameter a GIS layer has been created that identifies those areas that may provide a corrosive environment to underground cast iron assets. The final map has been classified into three categories signifying: 'GROUND CONDITIONS BENEATH TOPSOIL ARE UNLIKELY TO CAUSE CORROSION OF IRON', 'GROUND CONDITIONS BENEATH TOPSOIL MAY CAUSE CORROSION TO IRON', 'GROUND CONDITIONS BENEATH TOPSOIL ARE LIKELY TO CAUSE CORROSION TO IRON'. The dataset is designed to aid engineers and planners in the management of and maintenance of underground ferrous assets.