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The evolution of shale’s mechanical properties with confining pressure, temperature, and mineral composition directly influences fracture closure besides the effect of in situ stress variation across lithologies. We are the first to perform experimental study to characterize the mechanical properties of the Goldwyer gas shale formation located in the Canning Basin, Western Australia. We have performed constant strain rate multistage triaxial tests at in situ stress condition (confining pressure ≤ 22 MPa) on 15 samples of the Goldwyer gas shales with variable minerology, organic content, and heterogeneity. Deformation tests were conducted at room temperature and in drained conditions on cylindrical samples cored parallel (horizontal) and perpendicular (vertical) to the bedding plane. Both triaxial compressive strength (σTCS) and static young’s modulus E show a strong sensitivity to confining pressure and mineralogy, while only E shows a directional dependency, i.e., Eh > Ev. The internal friction coefficient µi in a plane parallel to the bedding is 0.72 ± 0.12, while it is only 0.58 ± 0.17 in the orthogonal direction. Both σTCS and E are significantly lower when larger fractions of weak mineral constituents are present (clays or organic matter). We observe that the Young’s modulus of most vertical samples is best approximated by Reuss’s bound, whereas that of horizontal samples is best approximated by Hill’s average of Voigt and Reuss bounds. The most prospective G-III unit of the Goldwyer shale formation (depth > 1510 m) is semi-brittle to brittle, making it suitable for future development.

To combat the increasing demand of renewable energy, development of effectual system for energy storage is needed. Salt caverns serve as the feasible and efficient solution for hydrogen storage. Studying the complex structure and analysing deformation behaviour of these formations requires clear geological domain knowledge, suitable numerical technique and proper computational model when going to predict long-term deformation and associated stress state. In this work, a 2D finite element simulator code has been utilized to probe deformation characteristics of salt formation. Two cases: (i) creep under monotonic loading, and (ii) creep under cyclic loading are deployed to investigate the influence of non-linear primary creep and change in stress magnitudes under in situ conditions. Damage and creep constitutive laws like generalized Hooke's Law, total potential energy principle, infinitesimal deformation theory etc are utilized in the simulation engine assuming constant strain triangle elements. At suitable boundary conditions, the model captured axial deformation under uniaxial compression condition of the studied salt formation with the experimental data. A good match of compressive axial deformation is observed between experimental and numerical results. Finally, the model will be extended to understand permeability evolution under monotonic loading and possible relationship with volumetric change from gas transmission permeability measurement., Open-Access Online Publication: May 29, 2023

In recent years, short-term creep parameters determined in the laboratory from cylindrical gas shale samples subjected to triaxial (in-situ) stress conditions have been used successfully to infer long-term deformation and stress relaxation at the reservoir scale across geologic time scales. Due to the viscoelastic formalism, both the laboratory creep response and field-scale stress relaxation can be modeled with power law functions of time involving the elastic compliance of the shale B, the time-dependence exponent n, and the amount of total strain ∊. Gas shales often exhibit a high specific surface area associated with their high content in clay minerals and/or total organic carbon (TOC). The low-pressure nitrogen adsorption technique can be used advantageously to estimate specific surface area (SN2); i.e., it is a relatively fast and cost-effective measurement conducted on powdered samples of shale material. A robust global empirical correlation between gas shale creep parameters and SN2 emerges from the analysis of laboratory data collected from multiple gas shale formations in Australia (the prospective Goldwyer Formation) and the United States (Barnett, Haynesville, and Eagle Ford formations), and spanning a broad range of clay content, organic matter, maturity, and porosity values. This data set also shows that the summed fractions of clay minerals, TOC, and porosity, the so-called weak phase fraction, correlates nearly as well with primary creep parameters. The weak phase fraction can also be estimated from faster and more cost-effective measurements or from well logs. To evaluate its predictive capacity, the key correlation between SN2 and creep parameters is used in a case study to predict the magnitude of present-day least principal stress Shmin across six depth intervals/lithologic layers in a prolific unconventional shale formation in the northeastern United States. Several Shmin measurements are available for verification, and our approach successfully captures the observed layered variation of stress with depth.

Background: Contrast-induced acute kidney injury (CI-AKI) is one of the most common causes of hospital-acquired AKI. This study was aimed to analyse the incidence of CI-AKI and associated risk factors in hospitalized patients undergoing CT or Catheter related contrast based procedures. Materials and Methods: This cross-sectional observational study was conducted between September 2016 and August 2018. Hospitalized patients of either sex, aged >18 years scheduled for contrastenhanced computed tomography (CECT), peripheral angiography (PAG), percutaneous transluminal coronary angioplasty (PTCA), or coronary angiography (CAG), with eGFR >30 were evaluated for CIAKI after excluding other causes of AKI. Results: A total of 300 patients were enrolled, of which 266 patients completed the study (CECT/PAG, n=138; PTCA/CAG, n=128). The mean age of the patients was 45.85 15.14 years and the majority of patients were males (n=164, 61.6%). The incidence of CI-AKI was 15.6% (n=41). A total of 28.8% of patients with diabetes and 31.1% patients aged >60 years developed CI-AKI. Overall, the increasing contrast volume significantly (p=0.002) increased the incidence of CI-AKI. The incidence of CI-AKI in patients mild renal dysfunction increased significantly (from 5.5% at

Recently short-term laboratory primary creep i.e., time-dependent deformation under triaxial in situ stress condition of ultra-low permeable gas shales have been utilized to work out geomechanical impacts of field development cycle such as modification of in situ stress state, prediction of production induced deformation, and understanding of fracture closure mechanism. However, obtaining creep data from the laboratory method is tedious, time-consuming, and costly. A simple power law model as a function of time involving instantaneous elastic compliance of the studied material B, and time dependent component n is used to describe creep and stress relaxation owing to the superposition principle of linear viscoelastic materials. Gas shales usually have a large specific surface area (SSA) because of the dominance of clay minerals (Illite, Smectite, Kaolinite, and Chlorite) and/or total organic carbon (TOC). Low-pressure nitrogen gas adsorption is a quick and cost-effective method to derive specific surface area value SN2 on powdered gas shale samples. From the observed strong empirical correlation between creep parameters and SN2value as well as with weak phase fraction ClayTocPHI (combination of clay, porosity, and TOC), a novel indirect approach is proposed to predict primary creep constitutive parameters either from the specific surface area (SSA) value SN2 or weak phase fraction ClayTocPHI of multiple gas shales at deeper subsurface formations (Figure 1). These gas shales cover a broad range of mineralogy, maturity, porosity, and depositional history. Through a case study, empirically derived creep parameters from SN2 are utilized to predict the least principal stress Shmin magnitude at depth of a six lithological layered gas shale formation with a viscoelastic stress relaxation approach. Direct field measurement validated the layered variation of the predicted Shmin magnitude.

The petroleum industry progressed significantly to develop 3D/4D geomechanical models (GMs) to make efficient field development planning which reduces the uncertainty of 1D GM in the field scale. In this paper, we demonstrated how to build a high-resolution 3D static GM in a stratigraphic structural setup with a combination of wireline logs, drilling data, structural objects, and laboratory rock mechanical data from 21 core samples in the Ichthys field of the Browse Basin, North West Shelf so that spatial distribution of pore pressure and stress behaviour can be understood across the Brewster Member sandstone reservoir. The workflow incorporates calibrated 1D GM of seven wells. 1D GM analysis confirmed strike-slip faulting regime throughout the stratigraphic column and the orientation of maximum principal stress is nearly towards the E-W direction. The 1D model also indicates a sharp pressure ramp within Jamieson reaching a maximum to the middle of the layer and then regressed below Aptian and near to hydrostatic pressure at top of the upper Vulcan formation. 3D modelling is performed by incorporating interpreted seismic surfaces and unconformities in line with the geological understanding of the subsurface and stratigraphic variation from the seabed to lower Vulcan formation. A geostatistical technique is adopted to map and interpolate rock properties throughout the grid which is tied with the field's stratigraphic unit. A seismic velocity cube is used to compute density profile based on acoustic-density correlation and thereafter vertical stress. Pore pressure is modelled by defining the pressure depth relationship from the 1D reference pore pressure profile and honouring the structural layering. Due to its inherent property of structural consistency, this 3D model efficiently captures the lateral heterogeneity over the 1D model validated at Prelude-1A well location., Open-Access Online Publication: March 01, 2023

Production from ultra-low permeable gas shale reservoirs is feasible only through hydraulic fracturing stimulation. Slip along a pre-existing natural network of fractures/faults with the injection of hydraulic fluid is mostly controlled by the frictional properties of the shale. We studied the deformation characteristics of the Goldwyer shale formation at in-situ stress conditions by performing a series of multistage triaxial tests to understand compositional controls on fault slip accompanying hydraulic fracturing. The Coulomb friction coefficient is derived from the post-failure axial displacement and the angle of the final failure plane. When the clay and total organic content (TOC) of the studied shale samples are above ~40% by volume, the friction coefficient approaches a value of 0.6, while below this threshold it is higher. This change suggests a transition from a grain-bearing to a clay-bearing structure. Therefore, we can directly estimate the slip tendency of natural faults and fractures in gas shale reservoirs from their clay and TOC content., Open-Access Online Publication: March 03, 2023

Accurate and precise identification of lithological facies is vital to understand geological variation in a proven reservoir. Four specific different machine learning (ML) classification algorithms...

Introduction: HIV and tuberculosis (TB) are two of the most challenging infections faced by humanity and place immense burden on health care systems worldwide. Both HIV and TB impact one another's progression.Areas covered: HIV is the most important risk factor for progression of latent TB to active disease. TB is the most common cause of death among People Living with HIV (PLHIV). Timely detection of TB among PLHIV and screening for HIV among TB patients, early initiation of ART and ATT among coinfected persons, provision of CPT and TB Preventive therapy along with control of air-borne infection are some of the key activities to reduce morbidity and mortality among coinfected persons. Despite many challenges, the collaboration between two programs has yielded good results and globally more than 7.3 million lives of PLHIV have been saved globally through scale-up of collaborative TB/HIV activities since 2005. The review looked into key features of both programs that are the collaboration strategies and challenges that still need to be addressed.Expert opinion: The overarching principle for effective implementation of collaborative activities is integration of the TB and HIV national programs right from policy making to service delivery and monitoring.

Albumin is the major protein excreted in urine in patients with nephrotic syndrome (NS). However, low-molecular-weight proteins including some binding proteins are also excreted. Thyroid hormone and its binding globulins are excreted in urine in excess in nephrotic syndrome. Therefore, it has been postulated that patients with nephrotic syndrome may show hypothyroidism, subclinical or overt. In this prospective observational study, patients of idiopathic nephrotic syndrome aged 1–40 years of both gender were included. Serum T3, T4 and TSH were assayed at diagnosis and repeated at 12 weeks or at remission whichever was earlier. Renal biopsy was performed as required. Among 100 patients taken for analysis (42 children, 58 adult), 30 cases were of first episode, 40 were of frequent relapse/steroid-dependent NS, and 30 patients had steroid-resistant NS (SRNS). Three (3%) cases had overt hypothyroidism and 18 (18%) patients had subclinical hypothyroidism. Most hypothyroid cases belonged to SRNS subgroup. Mean Serum T3, T4 and TSH values showed significant improvement in remission in comparison to nephrosis state (P

The Deccan trap basalt, laid down by multiple lava flows during upper Cretaceous to Paleocene times forms the basement of current study in Cambay basin. As such, there is great interest and value in fracture detection and evaluation of fractured basement reservoirs in the Cambay basin. The procedure for identification and evaluation of natural as well as induced fractures in basaltic basement of the Cambay basin is presented in this work. In this study formation micro-imager (FMI) and extended range micro-imager (XRMI) log data for fracture identification is used. The Deccan trap basaltic basement of the study area, comprising five wells in the Tarapur-Cambay block, has potential for holding commercial hydrocarbon due to the presence of fractures and weathered basement. Both image logs (FMI, XRMI) identify three types of fracture including open (conductive), partially open and closed (resistive) fractures, of which open and partially open fractures are important for hydrocarbon accumulation. Fracture dip ranges from 10° to 80°. Image logs have also identified washout, breakout and drilling-induced fracture zones. The strike direction of the open natural fractures for four wells varies from N60°E to N30°E whereas the strike direction of most natural fracture in the fifth well is oriented towards N20°W. The orientations of drilling-induced fractures and breakouts may be interpreted for the in-situ stress direction over the logged interval. Drilling-induced tensile fractures, identified over the depth interval of 1969–1972 m, and borehole breakouts over the interval of 1953–1955 m in one well, suggest an orientation of maximum in-situ horizontal compressive stress (SH) lies in the north-south direction. The azimuths of open natural fractures in the same well vary from north-south to N30°E. It is expected that the direction of fluid flow will be controlled by open natural fractures and therefore would be in a direction parallel to the SH direction, which is orthogonal to the minimum horizontal stress (Sh) direction. The orientations observed are consistent with the present day SH direction in the study area of Cambay basin.

Summary Cost-effective hydrocarbon production from unconventional reservoirs relies on multi-stage hydraulic fracturing operations. Suitable shale intervals are usually identified on the basis of: (i) organic-richness; and (ii) mechanical brittleness to promote the creation of a multidirectional fracture network, and therefore a larger stimulated reservoir volume. The in-situ stress state notoriously governs shale deformation and fracturing processes at depth. In the Goldwyer shale formation (Canning Basin, Western Australia), existing well logs from the Theia-1 well are used to build a 1-D mechanical earth model through a brittleness analysis and direct validation with existing laboratory triaxial rock mechanics tests. A progressive transition with depth from a strike-slip (shallower intervals) to a hybrid faulting regime (deeper intervals) is inferred in the Goldwyer formation. The changing stress regime correlates with the estimated variation in dynamic elastic brittleness with depth. This analysis suggests a power law relationship between static Young’s modulus and deformational brittleness (B3). This power law function is then used to create a continuous brittleness profile along the well, across the entire Goldwyer formation interval. Based on this study, the G-III unit (1500m to 1590m in the Theia-1 well) of the Goldwyer formation is the most prospective for hydraulic fracturing operations.

Additional file 1 : Figure S1. Calibration results to incidence and mortality. Figure S2. Calibration results to additional indicators. Figure S3. Sensitivity analysis to assumptions for coverage and effectiveness of preventive therapy. Figure S4. Sensitivity analysis to model parameters. Table S1. List of state variables used in the model. Table S2. Epidemiological indicators for model calibration. Table S3. List of regional-level parameters used in the model. Table S4. Summary of country-wise parameter estimates. Table S5. Impact on cumulative TB incidence by country, and for the whole region, from 2019-2030. Table S6. Impact on cumulative TB mortality by country, and for the whole region, from 2019-2030. Table S7. Total impact of improved TB cascade and preventive therapy.

Compositional variation of rock properties in unconventional shale reservoirs impacts not only hydraulic fracturing stimulation but also the variability of induced shear slip on pre-existing fracture networks. Lithological layering is also responsible for varying stress states in various unconventional reservoirs subjected to normal, strike-slip, reverse or hybrid faulting regime (a combination of any two of them). Three possible mechanisms are considered to evaluate the layer-based stress profile in the sub-surface, that is viscoelastic stress relaxation, elevated pore pressure and variation in rock frictional strength. We conducted multistage triaxial deformation tests with varying strain rates (5×10−7 to 10−5s−1) on shale sample originating from three lithological units of the Goldwyer shale formation, that is G-I, G-II and G-III in the Broome platform of onshore Canning basin. Additionally, pore pressure was estimated from wireline logs, and tectonic stress accumulation was modelled using time-dependent deformation (creep) data. The above analysis suggests that varying frictional strength alone could not explain the variation of the least principal stress; however, the inclusion of stress relaxation also contributes, whereas elevated pore pressure has no effect. Using this approach, we could also relate the changes in minimum principal stress (Shmin) from one lithofacies to the other and anticipate how this will impact the optimum design of landing zone during horizontal drilling and completion in unconventional field development.

Profitable exploitation of unconventional shale gas reservoirs relies on the success of hydraulic fracturing stimulation. This is more likely in brittle rock formations because natural and hydraulic fractures remain open after stimulation, allowing for more hydrocarbon production. Identification of the most favourable depth intervals relies on the robust analysis of available well-logs, and on laboratory-derived mechanical and elastic data obtained under controlled stresses replicating the actual conditions at depth. Beyond their use for predictive geomechanical modelling such laboratory data can act as calibration points for existing well-logs. Well-logs can also be used to guide the selection of the rock samples to be characterised and tested in the laboratory, ensuring that they are representative of the rock formation. Here we apply the above principles and demonstrate how this improves the geomechanical appraisal of the Goldwyer formation and assesses its prospectivity. This workflow integrates Rock-eval geochemical analyses, elastic properties, anisotropy, in-situ stress state and pore pressure, mechanical brittleness and fracturing indices derived from petrophysical and sonic logs in the Theia-1 and Pictor East-1 wells. We estimated an average total organic carbon of 2 w. t.% (maximum 5 w. t.%), a moderate to high dynamic Young's modulus (14–52 GPa), a low Poisson's ratio (0.24–0.27), and an average elasticity-based brittleness index B1 of 41% in the deeper G-III unit. This unit also exhibits a low differential horizontal stress ratio and a high fracture index. Such attributes suggest a good prospectivity of the G-III unit, not only in terms of potential resources but as importantly in terms of fracability.

In 1998, the resurgence of Plasmodium vivax malaria in the Democratic People's Republic of Korea quickly increased to an epidemic, with 601 013 cases reported I during 1999-2001. The introduction of mass primaquine preventive treatment (MPPT) in 2002 was followed by a rapid reduction of malaria disease burden. The intervention has been well accepted by the community. Doctors were part of a strong functional health system with the ability to deliver interventions at the household J level. MPPT was considered for control of malaria after a study conducted in two J neighbouring endemic villages (ris) involving 320 healthy adults demonstrated that presence of parasitaemia was significantly lower among those receiving MPPT than those who did not. Similarly, in a mass blood survey conducted in the study sites during May, 2002 involving 5138 persons in study and 4215 in comparison areas, the total positive results were 7-10 times rarer in the treatment group both before and after the malaria transmission season. In addition, the number of malaria cases in the MPPT treatment ris was strikingly lower than control ris in every month during the malaria transmission season of 2002. The prevalence of G6PDD deficiency in DPR Korea is low, haemolytic events are rare and deaths due to MPPT have not been reported. MPPT in itself is a powerful intervention and the decision to deploy it depends on the epidemiology of malaria, urgency of malaria control and resources available in the country.

Almost half of the deaths worldwide caused by tuberculosis in 2018 occurred in the World Health Organization (WHO) South-East Asia Region, home to around a quarter of the global population. Maintaining robust progress in this region is therefore essential if the global goal of ending the tuberculosis epidemic is to be realized. Substantial gains have been made in the region, but the threat to health worldwide posed by the coronavirus disease 2019 (COVID-19) pandemic includes not only the direct effects of the pandemic but also the potential eclipsing of the global tuberculosis emergency. The results of modelling studies present stark warnings of a reversal of years of progress and a significant resurgence in deaths from tuberculosis. The COVID-19 pandemic has had variable impacts in the WHO South-East Asia Region to date, but in the countries most affected there has been targeted diversion and repurposing of tuberculosis services, health-care workers and diagnostic equipment. The combined effects of COVID-19, containment measures and fragmentation of tuberculosis services have resulted in delays in diagnosis or non-diagnosis and disruption in treatment resulting in increased morbidity, mortality, transmission and drug resistance. Countries of the region have made attempts to ensure continuity of services and civil society and nongovernmental organizations have instituted a range of innovative mechanisms to support national programmes. However, a comprehensive approach - including scaling up successful initiatives, empowering community leadership, harnessing digital tools, and implementing easily accessible cash transfers and nutrition support - will be critical to success. As COVID-19 recedes, countries will need "catch-up plans" to deploy supplementary measures to address the increased tuberculosis burden. Urgent, targeted and agile responses have the potential to mitigate and reverse the impact of the COVID-19 pandemic on tuberculosis in South-East Asia.

Cost-effective hydrocarbon production from low-permeability unconventional reservoirs requires multi-stage hydraulic fracturing (HF) operations. Each HF stage aims to generate the most spatially extended fracture network, giving access to the largest volume of reservoir possible (stimulated volume) and allowing hydrocarbons to flow towards the wellbore. The size of the stimulated volume, and therefore, the efficiency of any given HF stage, is governed by the rock’s deformational behaviour and presence of pre-existing natural fractures/faults. Naturally elevated pore pressures at depth not only help to reduce the injection energy required to generate hydraulic fractures but can also induce slip along pre-existing fractures/faults, and therefore, enhance production rates. Here we analyse borehole image, density, resistivity and sonic logs available from a vertical exploration well in the Goldwyer Shale Formation (Canning Basin) to (i) characterise the pre-existing network of natural fractures; and (ii) estimate the in-situ pore pressure and stress state at depth. The aim of such an analysis is to evaluate the possibility of fracture/fault reactivation (slip) during and following HF operations. Based on this analysis, we found that an increase in the formation's pore pressure by only a few MPa (typically ~5–10 MPa) could lead to slip along pre-existing fractures/faults, provided they are favourably oriented with respect to the prevalent stress field for future production. We also found that slip along the horizontal or sub-horizontal bedding of the Goldwyer Formation is unlikely in view of the prevalent strike-slip faulting regime, unless an extremely large overpressure exists within the reservoir.

Background & objectives: To support recent political commitments to end tuberculosis (TB) in the World Health Organization South-East Asian Region (SEAR), there is a need to understand by what measures, and with what investment, these goals could be reached. These questions were addressed by using mathematical models of TB transmission by doing the analysis on a country-by-country basis in SEAR. Methods: A dynamical model of TB transmission was developed, in consultation with each of the 11 countries in the SEAR. Three intervention scenarios were examined: (i) strengthening basic TB services (including private sector engagement), (ii) accelerating TB case-finding and notification, and (iii) deployment of a prognostic biomarker test by 2025, to guide mass preventive therapy of latent TB infection. Each scenario was built on the preceding ones, in successive combination. Results: Comprehensive improvements in basic TB services by 2020, in combination with accelerated case-finding to increase TB detection by at least two-fold by 2020, could lead to a reduction in TB incidence rates in SEAR by 67.3 per cent [95% credible intervals (CrI) 65.3-69.8] and TB deaths by 80.9 per cent (95% CrI 77.9-84.7) in 2035, relative to 2015. These interventions alone would require an additional investment of at least US$ 25 billion. However, their combined effect is insufficient to reach the end TB targets of 80 per cent by 2030 and 90 per cent by 2035. Model projections show how additionally, deployment of a biomarker test by 2025 could end TB in the region by 2035. Targeting specific risk groups, such as slum dwellers, could mitigate the coverage needed in the general population, to end TB in the Region. Interpretation & conclusions: While the scale-up of currently available strategies may play an important role in averting TB cases and deaths in the Region, there will ultimately be a need for novel, mass preventive measures, to meet the end TB goals. Achieving these impacts will require a substantial escalation in funding for TB control in the Region.

In 1998, the resurgence of Plasmodium vivax malaria in the Democratic People's Republic of Korea quickly increased to an epidemic, with 601 013 cases reported I during 1999-2001. The introduction of mass primaquine preventive treatment (MPPT) in 2002 was followed by a rapid reduction of malaria disease burden. The intervention has been well accepted by the community. Doctors were part of a strong functional health system with the ability to deliver interventions at the household J level. MPPT was considered for control of malaria after a study conducted in two J neighbouring endemic villages (ris) involving 320 healthy adults demonstrated that presence of parasitaemia was significantly lower among those receiving MPPT than those who did not. Similarly, in a mass blood survey conducted in the study sites during May, 2002 involving 5138 persons in study and 4215 in comparison areas, the total positive results were 7-10 times rarer in the treatment group both before and after the malaria transmission season. In addition, the number of malaria cases in the MPPT treatment ris was strikingly lower than control ris in every month during the malaria transmission season of 2002. The prevalence of G6PDD deficiency in DPR Korea is low, haemolytic events are rare and deaths due to MPPT have not been reported. MPPT in itself is a powerful intervention and the decision to deploy it depends on the epidemiology of malaria, urgency of malaria control and resources available in the country.