This dataset is used and fully described/interpreted in the paper: Passelegue, F. X., N. Brantut, T. M. Mitchell, Fault reactivation by fluid injection: Controls from stress state and injection rate, submitted to Geophys. Res. Lett. Text files contain raw and processed data. Mechanical data are raw. Load needs to corrected (offset) from piston friction, measured at the beginning of each run before the hit point. Axial displacement is converted into sample shortening by correcting the load from machine stiffness, which is equal to 480 kN/mm (calibrated on Mon. 14 Mar. 2016). Data include a set of elastic wave first arrival times, obtained from time of flight measurements using an array of piezoelectric transducers and the cross-correlation method detailed in Brantut (2015) (see reference above). Two separate files correspond to mechanical data from experiments conducted at 50 and 100 MPa confining pressure (""mech_Pc=???MPa.txt""). One file (""sensors.txt"") contains the initial positions of each piezoelectric transducer. Files named ""wave_?_Pc=100MPa.txt"" (?=1,2,3 or 4) contain time series of arrival times during the four injections conducted at Pc=100MPa. Each column consists in the time-of-flight between a given pair of sensors (x->y, where x is the index of source sensor, and y is the index of the receiver sensor, as per their numbering in the ""sensors.txt"" file.) In all the data files, the first column corresponds to a common time basis, in seconds.

Through manufacturing and geophysically characterising the properties and distribution of a range of synthetic gas hydrate morphologies in a range of sediments in the laboratory, protocols will be established for geophysically logging natural sediment-hydrate core preserved in pressure chambers on board ship. Based on pressure cycling, geophysical behaviour responses will be determined during the start of dissociation and formation. On this basis the investigators then propose to develop protocols to characterise and classify hydrates sampled during ODP Leg 204, significantly improving our understanding of the nature and behaviour of these sediments. This new knowledge will enhance geophysical survey data, better constrain estimates of in-situ hydrates and improve the evaluation of hydrate destabilisation on methan release and slope stability.

Two published papers: Modelling the Lost City Hydrothermal Field: Influence of topography and Permeability structure. https://doi.org/10.1111/gfl.12151: and Rapid generation of reaction permeability in the roots of black smoker systems, Troodos ophiolite Cyprus. https://doi.org/10.1111/gfl.12117

to provide reliable molecular fingerprints for biodegraded crude oils and contaminated sediment cores and to facilitate correlation studies The aim is to demonstrate the potential of hydropyrolysis (pyrolysis assisted by high hydrogen gas pressure) as a novel means to provide reliable molecular fingerprints for biodegraded oils and contaminated cores where conventional biomarker approaches fail. This will then facilitate accurate and rapid oil-source and oil-oil correlations to be determined for the first time in these situations. New experimental protocols for conducting hydropyrolysis on asphaltenes will be developed. The study will establish a firm base to exploit the commercial potential of hydropyrolysis, both in oil exploration and for characterising sedimentary organic matter as a far superior technique to pyrolysis-GC-MS through a larger industrial partner.

The aim is to realise the potential of hydropyrolysis (pyrolysis assisted by high hydrogen gas pressures) as a means to provide reliable molecular fingerprints for severely biodegraded oils, contaminated cores, oil-field solids (tar mats and pyrobitumens) and to provide novel information on basin-filling history where the conventional free-biomarker approach fails. This will then facilitate rapid and accurate oil-source and oil-oil correlations to be determined for the first time in ocean-margin regions. The study will establish a firm base to exploit the commercial potential of hydropyrolysis, both in terms of oil exploration through the new correlations with bound biomarker profiles and of characteristic sedimentary organic matter as a far superior technique to py-GC-MS. Indeed, innovative experimental protocols for conducting hydropyrolysis will continue to be developed to have a prototype system ready for future exploitation.

Predicting oil production from chalk reservoirs relies on quantifying contributions from fracture and matrix porosity, which change during compaction. Cl isotopes in water characterise fluid transport processes. Chalk matrix microporosity and fractures will give different values. We will combine two novel methods, trace water extraction from dry oil and Cl isotopes to characterise porosity from produced fluid. High pressure lab. experiments carrying fracture/matrix porosity in cores will give characteristic brine geochemistry related to poroperm to calibrate field values. We will compare fluid derived porosity regime with values measures on field core. Porosity changes from geochemistry will be compared with compaction in the field.

The aim of the proposed project is to study evolution in the spatial characteristic of coupled flow and porosity development in heterogeneous porous media. We will develop a modelling engine and methodologies to generate porosity templates for use in flow and transport models of fractured aquifers. Although the primary motivation for this study is to enhance our ability to predict flow and contaminant transport in vulnerable fractured aquifers, such as the chalk, the approach is generic and we foresee a wide range of scenarios where the model may be applied. The work has three specific objectives: 1) to produce a generic model of porosity development, 2) to investigate percolation, scaling and self-organisation phenomena in porosity development due to flow, and 3) to model pore structure and flow histories for a range of natural and anthropogenic problems.

Coupled (mechanical-hydraulic) numerical models based on the distinct element method will be used to investigate the behaviour of fluid flow in fractured rock-masses under stress. Flow localization is predicted at some critical stress; parameters affecting this localization will be investigated. Flow in the vicinity of boreholes and by grain infiltration will be simulated. The models will be tested against field observations and hydraulic tests in boreholes.

This project is designed to integrate geological structural characterisation of fault zones with numerical modelling of flow behaviour at different scales. We will develop a 3D flow simulator which can model the impact of geological heterogeneities (clustered fault / fracture arrays) under different stress conditions on fluid flow. The project is collaboration between a structural geology research group (the rock deformation research group), an applied mathematics group (the centre for computational fluid dynamics) and a series of industrial partners (Arco, BP, Shell and Midland Valley).

The project will develop and explore the application of scaling methods to strongly heterogeneous flow fields; investigate the loss and retention of information by scaling over large space and long time scale ranges; and, define the dependence between large space/long time scale migration behaviour and the underlying geological model. High resolution, highly accurate flow and transport simulation data sets for a large number of realisations possessing the high variance and strong textures observed in actual geological systems using alternative geological simulators will be used to test upscaling approaches reported in the physical sciences literature and to identify improving upscaling laws where the existing laws are inadequate.