New interest in the potential for shale gas in the United Kingdom (UK) has led to renewed exploration for hydrocarbons in the Carboniferous age Bowland–Hodder shales under Central and Northern England. Following an incidence of induced seismicity from hydraulic fracturing during 2010 at Preese Hall, Lancashire, the publically available databases quantifying the in-situ stress orientation of the United Kingdom have shown to be inadequate for safe planning and regulation of hydraulic fracturing. This paper therefore reappraises the in-situ stress orientation for central and northern England based wholly on new interpretations of high-resolution borehole imaging for stress indicators including borehole breakouts and drilling-induced tensile fractures. These analyses confirm the expected north northwest – south southeast orientation of maximum horizontal in-situ stress identified from previous studies (e.g. Evans and Brereton, 1990). The dual-caliper data generated by Evans and Brereton (1990) yields a mean SHmax orientation of 149.87° with a circular standard deviation of 66.9°. However the use of borehole imaging without incorporation of results from older dual-caliper logging tools very significantly decreases the associated uncertainty with a mean SHmax orientation of 150.9° with a circular standard deviation of 13.1°.\ud \ud The use of high-resolution borehole imaging is thus shown to produce a more reliable assessment of in-situ stress orientation. The authors therefore recommend that the higher resolution of such imaging tools should therefore be treated as a de-facto standard for assessment of in-situ stress orientation prior to rock testing. Use of borehole imaging should be formally instituted into best practice or future regulations for assessment of in-situ stress orientation prior to any hydraulic fracturing operations in the UK

Over the past two decades, many decision support systems (DSSs) have been developed to support decision makers and facilitate the planning and redevelopment process of brownfields. Existing systems are however often siloed in their approach and do not fully capture the complexity of brownfield sites from a sustainable development point of view. This critical review provides an insight into the development and implementation of DSSs, published and emerging, together with assessment of their strengths, limitations and opportunities for future integration. Brownfields DSS applications include: remediation technology selection; and land use planning; and risk assessment. The results of this review lead the authors to identify four opportunities to improve brownfield DSSs: (i) increased use of qualitative socioeconomic criteria, particularly costs and economic variables, (ii) decision-support during the early stages of brownfield redevelopment, (iii) the integration of predictive modelling methods, and (iv) improvements of user interfaces and modern web-based functionalities.

An accurate and reliable description of the porosity–permeability relationship in geological materials is valuable in understanding subsurface fluid movement. This is important for reservoir characterisation, energy exploitation, geological carbon storage (GCS) and groundwater contamination and remediation. Whilst the relationship between pore characteristics and porosity and permeability are well examined, further investigation into the influence of grain characteristics on porosity and permeability would be beneficial due to the inherent relationship between grains and pores. This work aims to determine whether incorporation of grain characteristics into a porosity–permeability model is effective in constraining this relationship. Two fully digital approaches to individual 3D grain analysis based upon watershed segmentation are compared to determine the most effective, yet simple, workflow applicable to core plugs of significantly compacted grains. The identification of an effective segmentation workflow will facilitate future work on similarly complex materials, removing the need for traditional time-consuming and manual techniques. We use the most effective approach of measuring grain shape (sphericity) and size (Feret diameter) alongside an established fully digital workflow to measure porosity and permeability to investigate the impact of grain characteristics on porosity and permeability. We show that grain sphericity and porosity exhibit a positive relationship whereas no such relationship exists with grain size. Measurements of grain sphericity are applied to calculate a Kozeny–Carman (K–C) type porosity–permeability fit which was found to be unsatisfactory, compared to a simpler fit excluding any grain parameters. This is possibly due to the lower sphericity of the studied grains, deviating significantly from the K–C assumption that grains are entirely spherical. The simpler fit is most suitable for the studied materials, showing that inclusion of grain characteristics is not effective for better defining the porosity–permeability relationship in a K–C paradigm for these samples. This highlights the need for a model capable of considering a range of grain sphericities to further constrain the porosity–permeability relationship.