Chlorite, an Fe- and Mg-rich aluminosilicate clay, may be either detrital or authigenic in sandstones. Detrital chlorite includes mineral grains, components of lithic grain, matrix grain coats. Authigenic grain-coating, pore-filling grain-replacing. Chlorite can observed quantified by a range laboratory techniques including light optical scanning electron microscopy X-ray diffraction; the presence sandstone identified careful integration signals from downhole logs. Grain-coating is only type...

Increasing greenhouse gas emissions have put pressure on global economies to adopt strategies for climate-change mitigation. Large-scale geological hydrogen storage in salt caverns and porous rocks has the potential achieve sustainable energy storage, contributing development of a low-carbon economy. During is injected extracted through cemented cased wells. In this context, well integrity leakage risk must be assessed in-depth investigations hydrogen-cement-rock physical geochemical...

Abstract:  Clay-coated grains can inhibit ubiquitous, porosity-occluding quartz cement in deeply buried sandstones and thus lead to anomalously high porosity. A moderate amount of clay that is distributed as grain coats good for reservoir quality sandstones. Being able predict the distribution clay-coated sand petroleum reservoirs important help find exploit quality. Here we have adopted a high-resolution, analogue approach, using Ravenglass Estuary marginal-shallow marine system, NW...

Abstract Lakes are sensitive indicators of the balance between accommodation and sediment supply, recording high‐resolution changes in palaeoenvironmental conditions. Long‐lived rift lake basins, however, predominantly controlled by episodic pronounced basinward facies shifts, complicating generalisation tectonic climatic controls on successions. This study proposes a sequence framework depositional pattern for asymmetric half‐grabens syn‐rift basins characterising lacustrine fan‐delta...

Optically stimulated luminescence (OSL) dating of single grains is often required to determine an accurate age for partially-bleached sediment by identifying those with OSL signals that were well bleached prior burial. However, single-grain De distributions are typically characterised greater amounts scatter in comparison multiple grains. Here we investigate the quartz from 56 proglacial samples associated retreat last British-Irish Ice Sheet. Our findings provide first empirical dataset...

The spatial distribution of clay minerals and authigenic-clay-coated sand grains in ancient deeply buried petroleum reservoirs, which can enhance or degrade reservoir quality, is poorly understood. Authigenic coats are reported to originate from the thermally driven recrystallization detrital through situ growth authigenic alteration precursor early-diagenetic during burial diagenesis. To help predict estuarine sandstones, this study provides first modern-analogue study, using Ravenglass...

Shearing of magma during ascent can promote strain localisation near the conduit margins. Any mechanical and thermal discontinuities associated with such events may alter chemical, physical rheological stability thus its propensity to erupt. Lava spines record processes, preserving a range macroscopic microscopic deformation textures, attributed shearing friction, as ascends through viscous-brittle transition. Here, we use multidisciplinary approach combining petrology, microstructures,...

Lava dome collapses pose a hazard to surrounding populations, but equally represent important processes for deciphering the eruptive history of volcano. Models examining lava instability rely on accurate physical and mechanical properties volcanic rocks. Here we focus determining suite temporally-constrained rocks from different phases 1995-2010 eruption at Soufrière Hills volcano in Montserrat. We determine uniaxial compressive strength, tensile density, porosity, permeability, Young's...

Abstract The spatial distribution of clay minerals in sandstones, which may both enhance or degrade reservoir quality, is poorly understood. To address this, mineral patterns and host‐sediment properties (grain size, sorting, fraction abundance bioturbation intensity) have, for the first time, been determined mapped at an unprecedentedly high‐resolution a modern estuarine setting (Ravenglass Estuary, UK ). Results show that estuary sediment dominated by illite with subordinate chlorite...

Primary depositional mineralogy has a major impact on sandstone reservoir quality. The spatial distribution of primary in sandstones is poorly-understood and consequently empirical models typically fail to accurately predict To address this challenge, we have determined the detrital minerals (quartz, feldspar, carbonates clay minerals) surface sediment throughout Ravenglass Estuary, UK. We produced, for first time, high resolution maps mineral quantities over an area that similar many oil...

Extraction or injection of fluids within the subsurface causes fluctuations fluid pressures and thus stress conditions. It is paramount to have knowledge geomechanical strength a system's lithologies, factors that control it, in order maintain optimal conditions during extraction/injection. If yield strengths reservoir caprock are overcome, particularly near-wellbore region where amplified, these could potentially compromise system, through compactional dilatational failure. Here we used...

Abstract The specific mineralogy of clay grain coats controls the ability coat to inhibit quartz cementation in sandstones during prolonged burial and heating. How why clay‐coat varies across marginal marine systems is poorly understood, even though these eogenetic phenomena strongly influence subsequent mesodiagenesis reservoir quality. novel development predict distribution would represent an important for sandstone quality prediction. In sediments, minerals occur as grain‐coats,...

A major limiting factor in efforts to develop a predictive capability for the distribution of clay-coat-derived positive reservoir quality anomalies, deeply-buried sandstones, has been lack reliable and user-independent method quantify extent clay-coat coverage. Clay minerals attached grain surfaces as coats (rims) have reported inhibit quartz cementation during prolonged burial heating so preserve deep sedimentary basins. The completeness coverage is principal that controls effectiveness...

Abstract Chlorite is a key mineral in the control of reservoir quality many siliciclastic rocks. In deeply buried reservoirs, chlorite coats on sand grains prevent growth quartz cements and lead to anomalously good quality. By contrast, an excess – for example, clay-rich siltstone sandstone leads blocked pore throats very low permeability. Determining which compositional type present, how it occurs spatially, quantifying varied habits that are commercial importance remains challenge. With...

Petroleum-rich basins at a mature stage of exploration and production offer many opportunities for large-scale Carbon Capture Storage (CCS) since oil gas were demonstrably contained by low-permeability top-sealing rocks, such as shales. For CCS to work, there must be effectively no leakage from the injection site, so nature top-seal is an important aspect consideration when appraising prospective opportunities. The Lower Cretaceous Rodby Shale Palaeocene Lista have acted seals accumulations...

Explosive volcanic eruptions produce vast quantities of silicate ash, whose surfaces are subsequently altered during atmospheric transit. These mediate environmental interactions, including ice nucleation, and toxic effects in biota. A lack knowledge the initial, pre-altered ash surface has required previous studies to assume that composition created magmatic fragmentation is equivalent bulk particle assemblage. Here we examine particles generated by controlled andesite find generates with...

Geothermal fields are prone to temperature fluctuations from natural hydrothermal activity, anthropogenic drilling practices, and magmatic intrusions. These may elicit a response the rocks in terms of their mineralogical, physical (i.e., porosity permeability), mechanical properties. Hyaloclastites highly variable volcaniclastic rock predominantly formed glass clasts that produced during nonexplosive quench-induced fragmentation, both subaqueous subglacial eruptive environments. They common...

Detrital grain-coating clay minerals have been identified as precursors of diagenetic that inhibit quartz cementation and preserve good reservoir quality properties in deeply buried sandstone reservoirs. Between initial final deposition, detrital grain coats are likely to be affected by sediment transport processes. To date, it has not demonstrated clays able survive transport. Flume experiments simulating open-channel flow conditions were performed using sediments from the Ravenglass...

Protracted volcanic eruptions may exhibit unanticipated intensifications in explosive behaviour and attendant hazards. Santiaguito dome complex, Guatemala, has been characterised by century-long effusion interspersed with frequent, small-to-moderate (<2 km high plumes) gas-and-ash explosions. During 2015–2016, explosions intensified generating hazardous ash-rich plumes (up to 7 high) pyroclastic flows. Here, we integrate petrological, geochemical geophysical evidence evaluate the causes of...