Meteorological-tsunami-like (or meteotsunami-like) periodic oscillation was muographically detected with the Tokyo-Bay Seafloor Hyper-Kilometric Submarine Deep Detector (TS-HKMSDD) deployed in the ...underwater highway called the Trans-Tokyo Bay Expressway or Tokyo Bay Aqua-Line (TBAL). It was detected right after the arrival of the 2021 Typhoon-16 that passed through the region 400 km south of the bay. The measured oscillation period and decay time were respectively 3 h and 10 h. These measurements were found to be consistent with previous tide gauge measurements. Meteotsunamis are known to take place in bays and lakes, and the temporal and spatial characteristics of meteotsunamis are similar to seismic tsunamis. However, their generation and propagation mechanisms are not well understood. The current result indicates that a combination of muography and trans-bay or trans-lake underwater tunnels will offer an additional tool to measure meteotsunamis at locations where tide gauges are unavailable.
This work extends an existing analytical solution for pressure buildup because of CO2 injection in brine aquifers by incorporating effects associated with partial miscibility. These include ...evaporation of water into the CO2 rich phase and dissolution of CO2 into brine and salt precipitation. The resulting equations are closed‐form, including the locations of the associated leading and trailing shock fronts. Derivation of the analytical solution involves making a number of simplifying assumptions including: vertical pressure equilibrium, negligible capillary pressure, and constant fluid properties. The analytical solution is compared to results from TOUGH2 and found to accurately approximate the extent of the dry‐out zone around the well, the resulting permeability enhancement due to residual brine evaporation, the volumetric saturation of precipitated salt, and the vertically averaged pressure distribution in both space and time for the four scenarios studied. While brine evaporation is found to have a considerable effect on pressure, the effect of CO2 dissolution is found to be small. The resulting equations remain simple to evaluate in spreadsheet software and represent a significant improvement on current methods for estimating pressure‐limited CO2 storage capacity.
Key Points
Analytical solution to estimate pressure buildup due to CO2 injection
Incorporates effects of brine evaporation and CO2 dissolution
Provides closed‐form expressions for location of shock fronts
Injecting CO2 into deep saline formations represents an important component of many greenhouse-gas-reduction strategies for the future. A number of authors have posed concern over the thousands of ...injection wells likely to be needed. However, a more important criterion than the number of wells is whether the total cost of storing the CO2 is market-bearable. Previous studies have sought to determine the number of injection wells required to achieve a specified storage target. Here an alternative methodology is presented whereby we specify a maximum allowable cost (MAC) per ton of CO2 stored, a priori, and determine the corresponding potential operational storage capacity. The methodology takes advantage of an analytical solution for pressure build-up during CO2 injection into a cylindrical saline formation, accounting for two-phase flow, brine evaporation, and salt precipitation around the injection well. The methodology is applied to 375 saline formations from the U.K. Continental Shelf. Parameter uncertainty is propagated using Monte Carlo simulation with 10 000 realizations for each formation. The results show that MAC affects both the magnitude and spatial distribution of potential operational storage capacity on a national scale. Different storage prospects can appear more or less attractive depending on the MAC scenario considered. It is also shown that, under high well-injection rate scenarios with relatively low cost, there is adequate operational storage capacity for the equivalent of 40 years of U.K. CO2 emissions.
Volcanic activity is often associated with the development of faulted lacustrine basins. Organic-rich shale in such basins usually contains abundant volcanic material. The influence of volcanic input ...on organic-rich shale deposition in the basin studied has not been discussed in detail. Based on the ten shale samples from three wells, this study analyzed the depositional environment of the Yingcheng Formation shale in the Lishu Fault Depression area of the Songliao Basin by using interpretation of logging, total organic carbon analysis, gas chromatography mass spectrometry analysis, and trace element analysis. The impact of fault break to basement and volcanic materials on the organic matter enrichment was evaluated. The results show that the organic matter of Ying 1 (Y1), the First Member of the Yingcheng Formation, in the Lishu Fault Depression is characterized mainly by type I kerogen. The shale of the Y1 Member, having high total organic carbon content, is laterally continuous and could be considered as a potential target for shale oil exploration. The shale with high total organic carbon was deposited in a freshwater deep lake under an anoxic environment. There is a significant input of volcanic material, especially around the Su2 well near the Sangshutai Fault. This study has established a sedimentary model of organic-rich shale in the faulted lacustrine basin affected by volcanic activity, which has significance for the exploration of shale oil in faulted lacustrine basins.
The Holywell Shale is part of the Carboniferous Bowland Shale Formation, identified as the main potential shale gas system in the UK. Here, we report geochemical and petrographic data from five ...outcrops of the Lower and Upper Holywell Shale across northeast Wales. At outcrop, the Holywell Shale is immature to early oil mature and has total organic carbon (TOC) values ranging between 0.1 and 10.3 wt %, with a mean of 1.9 wt %. Carbon isotope data clearly differentiate terrestrial and marine organic matter and show that both occur throughout the Holywell, with terrestrial sources (Type III/IV) dominating the Upper Holywell and marine sources dominating the Lower Holywell (Type II/III). Trace element data indicate that bottom waters were oxygenated, resulting in poorly preserved organic matter, supported by C/N and HI data. A range of silt- and clay-rich lithofacies occur, which show no relationship to either the amount or type of organic matter. We interpret the data in terms of a mixed supply of terrestrial and marine organic matter to marine depositional environments in which there was sufficient hydrodynamic energy to transport fine-grained sediment as bed load. The resulting mudstones exhibit a range of sedimentary textures with millimetre- to centimetre-scale silt–clay bed forms which show almost no relationship to organic matter type and amount. The small-scale variability and heterogeneity of both organofacies and lithofacies means that the reservoir quality of the Holywell Shale is inherently difficult to predict.
•We report geochemical and petrographic data from outcrops of the Holywell Shale.•δ13C isotopes show the source of organic matter changes from marine to terrestrial.•Negligible relationship between lithofacies and organic matter type/amount occurs.•Reservoir quality of the Holywell Shale is inherently difficult to predict.
The positive S-isotopic excursion of carbonate-associated sulfate (δ
34
S
CAS
) is generally in phase with the Steptoean positive carbon isotope excursion (SPICE), which may reflect widespread, ...global, transient increases in the burial of organic carbon and pyrite sulfate in sediments deposited under large-scale anoxic and sulphidic conditions. However, carbon-sulfur isotope cycling of the global SPICE event, which may be controlled by global and regional events, is still poorly understood, especially in south China. Therefore, the δ
13
C
PDB
, δ
18
O
PDB
δ
34
S
CAS
, total carbon (TC), total organic carbon (TOC) and total sulfate (TS) of Cambrian carbonate of Waergang section of Hunan Province were analyzed to unravel global and regional controls on carbon-sulfur cycling during SPICE event in south China.
The δ
34
S
CAS
values in the onset and rising limb are not obviously higher than that in the preceding SPICE, meanwhile sulfate (δ
34
S
CAS
) isotope values increase slightly with increasing δ
13
C
PDB
in rising limb and near peak of SPICE (130–160 m). The sulfate (δ
34
S
CAS
) isotope values gradually decrease from 48.6‰ to 18‰ in the peak part of SPICE and even increase from 18% to 38.5% in the descending limb of SPICE. The abnormal asynchronous C−S isotope excursion during SPICE event in the south China was mainly controlled by the global events including sea level change and marine sulfate reduction, and it was also influenced by regional events such as enhanced siliciclastic provenance input (sulfate), weathering of a carbonate platform and sedimentary environment. Sedimentary environment and lithology are not the main reason for global SPICE event but influence the δ
13
C
PDB
excursion-amplitude of SPICE. Sea level eustacy and carbonate platform weathering probably made a major contribution to the δ
13
C
PDB
excursion during the SPICE, in particularly, near peak of SPICE. Besides, the trilobite extinctions, anoxia, organic-matter burial and siliciclastic provenance input also play an important role in the onset, early and late stage of SPICE event.
Numerical simulation of compositional flow problems commonly involves the use of 1st- or 2nd-order Euler time stepping. Method of lines (MOL), using highly accurate and efficient ODE solvers, is an ...alternative technique which, although frequently applied to the solution of two-phase, two-component flow problems, has generally been overlooked for problems concerning more than two components. This article presents the development of a numerical simulator for 1D, compressible, two-phase, three-component, radially symmetric flow using the method of lines (MOL) and a 3rd-order accurate spatial discretization using a weighted essentially non-oscillatory (WENO) scheme. The MOL implementation enables application of the MATLAB ODE solver, ODE15s, for time integration. Simulation examples are presented in the context of
CO
2
injection into a reservoir containing a mixture of
CH
4
and
H
2
O
. Following an assumption of constant equilibrium ratios for
CO
2
and
CH
4
, a ternary flash calculator is developed providing closed-form relationships for exact interpolation between equations of state for
CO
2
–
H
2
O
and
CH
4
–
H
2
O
binary mixtures. The numerical code is successfully tested and verified for a range of scenarios by comparison with an existing analytical solution.
Hydrothermal-reactor experiments were conducted to investigate the potential formation of chlorite and microquartz grain coatings on detrital quartz and feldspar grains, and to understand their role ...in inhibiting the formation of quartz and feldspar (albite) overgrowths. Modern-day proximal and distal unconsolidated sediment from the Bute Inlet (British Columbia, Canada) with known amounts of precursor clay content, were used as starting material. The samples were heated to 250°C at water vapour pressure in a hydrothermal reactor for 72 h. The experiments were performed with and without a silica supersaturated Na
2
CO
3
(0.1 M) solution. Detailed microscopy and EDS mapping analysis identified that the main chlorite precursor, crucial for the formation of the synthesized grain coatings, was a Mg-rich chlorite. The experimental results showed that where the volume of precursor chlorite was low (i.e., 0.1%), notably in the proximal channel Bute samples, chlorite coatings were poorly developed, with a clay volume and maximum chlorite-coating coverage of 0.5% and 47%, respectively. In contrast, with an initial precursor chlorite volume of 14.5%, the distal lobe Bute sample has generated chlorite volume ranging from 42.9% to 56.3% post-experiment, with a maximum chlorite-coating coverage of 77%. The chlorite and microquartz coatings formed in the study are morphologically similar to those seen in natural sandstone reservoirs, and they have restricted the development of quartz and albite cementation in the reactor experiments. The findings provide quantitative data that can be utilised to describe diagenetic changes in mesodiagenetic environments.
Tight sandstone and shale oil and gas are the key targets of unconventional oil and gas exploration in the lake-delta sedimentary systems of China. Understanding the coevolutionary diagenesis of ...sandstone and shale reservoirs is crucial for the prediction of reservoir quality, ahead of drilling, in such systems. Thin-section description, scanning electron microscopy (SEM), X-ray diffraction (XRD), fluid inclusion analysis, porosity and permeability tests, high-pressure mercury intrusion (HPMI) measurements and nuclear magnetic resonance tests (NMR) were used to reveal the coevolutionary diagenetic mechanisms of a sandstone and shale reservoir in the Lianggaoshan Formation of the Eastern Sichuan Basin, China. The thermally mature, organic-matter-rich, dark shale of layer3 is the most important source rock within the Lianggaoshan Formation. It started to generate abundant organic acids at the early stage of mesodiagenesis and produced abundant hydrocarbons in the early Cretaceous. Porewater with high concentrations of Ca2+ and CO32− entered the sandstone reservoir from dark shale as the shale was compacted during burial. Potassium feldspar dissolution at the boundary of the sandstone was more pervasive than at the center of the sandstone. The K+ released by potassium feldspar dissolution migrated from the sandstone into mudstone. Grain-rimming chlorite coats occurred mainly in the center of the sandstone. Some silica exported from the shale was imported by the sandstone boundary and precipitated close to the shale/sandstone boundary. Some intergranular dissolution pores and intercrystal pores were formed in the shale due to dissolution during the early stages of mesodiagenesis. Chlorite coats, which precipitated during eodiagenesis, were beneficial to the protection of primary pore space in the sandstone. Calcite cement, which preferentially precipitated at the boundary of sandstone, was not conducive to reservoir development. Dissolution mainly occurred at the early stage of mesodiagenesis due to organic acids derived from the dark shale. Calcite cement could also protect some primary pores from compaction and release pore space following dissolution. The porosity of sandstone and shale was mainly controlled by the thickness of sandstone and dark shale.
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