Groundwater meets the majority portion of drinking water needs, particularly in the rural area of Bangladesh. Groundwater has been continuously contaminated by potentially harmful metals as a result of natural processes as well as some anthropogenic activity, creating a variety of health impacts....

Although reservoir characterization has been carried out by many researchers on the sedimentary package of the Bengal basin hydrocarbon province, integration of petrophysical and seismic sequence-based reservoir evaluation is rarely taken into account. This paper focuses on the identification of gas zones, reserve estimation and identification of new prospects in Srikail gas field within the eastern fold belt of Bengal basin integrating four wireline logs and 2D seismic data. Our study finds seven hydrocarbon-bearing zones (A, B, C, D, E, F and G) within the measured depth between 2429.5 and 3501 m. Petrophysical properties of seven hydrocarbon-bearing zones indicate that they are good quality reservoir sands. The gas horizons were mapped on seismic sections which reveal that the NW–SE anticlinal structure is largely affected by channels in the crest and western flank. The channels are infilled by fine-grained sediments which act as cap rock on northern and western parts of the structure. Thus, the anticlinal structure and fine-grained sediments make a potential trap for hydrocarbon accumulation and laterally and vertically well-distributed sequence remnants are the main reservoir rocks in this area. Volumetric reserve estimation of these sands provided a total gas initially in place as 552 billion cubic feet. Moreover, all the four wells are drilled in the southern block of the structure, and since there is a structural continuity from south to the north, it is highly recommended to drill a well up to 3000 m depth in the northern block to test its hydrocarbon potentiality. Overall, the outcomes of this study contribute new insights for reservoir characterization and identification of new prospects in an efficient way.

The mineralogical, geochemical, and statistical characteristics of recent fluvial deposits from the Brahmaputra–Jamuna River, Bangladesh, were examined to determine their provenance, transport dynamics, and depositional environment. Sediments were analyzed using X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WD-XRF), field emission scanning electron microscopy (FE-SEM), and electron probe microanalysis (EPMA). Grain size analysis revealed a predominance of medium-to-fine sand (mean grain size 1.77–3.43 ϕ), with moderately well-sorted textures (sorting: 0.33–0.77 ϕ), mesokurtic to leptokurtic distributions, and skewness values ranging from −0.21 to +0.30. Mineralogical results show a high quartz content with minor feldspar, mica, zircon, rutile, and iron-bearing minerals. Geochemical data indicates high SiO₂ (63.39%–70.94%) and Al₂O₃ (12.25%–14.20%) concentrations and calculated chemical index of alteration (CIA) values ranging from 60.90 to 66.82. The microstructural study revealed angular to sub-angular grains with conchoidal fractures and stepped microcracks, indicating brittle deformation under high-energy conditions, which is consistent with short transport distances, limited sedimentary recycling, and a derivation from mechanically weathered source rocks. Multivariate analyses (PCA and K-means clustering) of grain size parameters reveal two distinct sedimentary regimes, namely Cluster 1 as finer-grained (2.36 ϕ), poorly sorted sediments, and Cluster 2 as coarser (2.98 ϕ), well-sorted deposits. Discriminant function values (Y₂: 78.82–119.12; Y₃: −6.01 to −2.56; V₁: 1.457–2.442; V₂: 1.409–2.323) highlight shallow water, fluvial/deltaic aspects, and turbidite depositional environments. These findings advance the understanding of sedimentary dynamics within large, braided river basins and support future investigations into the sustainable management of fluvial depositional environments.