https://scialert.net Asian Journal of Earth Sciences en-us Science Alert Wed, 10 Jun 2026 18:11:57 +0200 Wed, 10 Jun 2026 18:14:14 +0200 RssPublisher 0.2.0 beta https://scialert.net/images/logo.gif https://scialert.net 41 233 Asian Journal of Earth Sciences Present-day in situ Pore Pressure Distribution in the Tertiary and Cretaceous Sediments of Zubair Oil Field, Iraq Background and Objective: Supergiant Zubair oilfield is one of the major hydrocarbon producing assets in southern Iraq. This study presents the assessment of pore pressure distribution across the tertiary and cretaceous sedimentary sequences in five producing wells. Materials and Methods: Indirect pore pressure estimation employing compressional sonic slowness responses as well as direct pressure measurements have been combined to establish regional pore pressure profiles. Results: Study reveals hydrostatic pressure regime in tertiary sediments. Late cretaceous Tanuma shales are under-compacted and therefore reveals mild overpressure, while the primary reservoir middle Cretaceous Mishrif limestones are in sub-hydrostatic pore pressure due to production related depletion. Conclusion: This study will be directly beneficial for determining minimum mud weight for drilling, since too high or too low mud weight can result into mud losses and wellbore collapses respectively leading to expensive non-productive time (NPT) in terms of drilling and loss of put on production (POP) time.]]> https://scialert.net/abstract/?doi=ajes.2020.1.11 10 June, 2026 Foraminiferal Assemblages from Recent Coastal Sediments of Chandipur, East Coast India Background and Objective: The study area, being in close proximity of the estuarine and river mouth, is vulnerable to potential mixing and distribution of pollutants along with the sediment load into the ecologically sensitive tidal flat microhabitat. This study was conducted for investigating foraminiferal assemblages from recent coastal sediments of Chandipur, India. Materials and Methods: Total ten perforated and agglutinated foraminiferal species have been identified under scanning electron microscope. Their systematics and morphologies have been documented. Results: Dominant species are Ammonia beccarii, Ammonia tepida, Haynesina germanica and Quinqueloculina seminulum, mostly found in sand flats. Habitat and substrate preferences of various foraminiferal species have been established from the studied foraminiferal assemblages. Conclusion: Study shows great abundance of low diversity, epifaunal to infaunal foraminifera’s assemblages in Chandipur sand flats, muddy tidal flats and marshlands.]]> https://scialert.net/abstract/?doi=ajes.2020.12.20 10 June, 2026 Petrophysical Analysis and Reservoir Characterization of Emerald Field, Niger Delta Basin, Nigeria Background and Objective: Re-evaluation of the Emerald Field in the Niger Delta Basin, Nigeria was done to produce 3D structural model of the field as well as identify and estimate the petrophysical properties of the reservoirs in the field. Materials and Methods: This was achieved by the use of 3D seismic volume and 4 wells from the field and the combination of techniques of well log analysis, seismic facies analysis, petrophysical analysis and seismic attribute analysis. Results: Integrated analysis of Gamma Ray, Resistivity, Neutron and Density logs shows that 3 hydrocarbon bearing reservoirs-Emy A, B and C-were penetrated by the 4 wells studied. The petrophysical analysis of the field reveals that reservoir porosity ranges from 10-29%, hydrocarbon saturation ranges from 0.75-0.84, water saturation ranges from 0.16-0.25, volume of shale ranges from 0.24-0.33 and net-to-gross ranges from 0.72-0.93. Five seismic facies were identified within the study area. Integrating the log motifs and results from the seismic facies analysis suggests the environment of deposition at different locations within the field to be distributary channel fills, overbank and floodplain deposits, which depicts paralic zone. Two prospects (Emerald prospect A and Emerald prospect B) and one lead were identified within the study area. Results of risk evaluation and estimated volume of hydrocarbon in place ranked Emerald prospect B as highest. Conclusion: It is therefore concluded that prospect for hydrocarbon exist in the Emerald field and the identified prospect should be tested for production.]]> https://scialert.net/abstract/?doi=ajes.2020.21.36 10 June, 2026 Quantitative Analysis and Characterization of Grain Size Distribution-Study from Recent Coastal Sediments of Chandipur, East Coast India Background and Objective: Characterization of sediment grain size and sorting on a beach are key input parameter to morphological models. The aim for analysis of these parameters helps to identify the spatial sediment distribution in active sedimentation environment. Materials and Methods: Recent coastal sediments has been studied from Chandipur beach, India; which has been designated as “Important Coastal and Marine Biodiversity Area” (ICMBA) for the coastal preservation as well as improved supervision of threatened and delicate coastal and marine flora and fauna. Results: Grain size variability on the present-day Chandipur beach has been interpreted. Statistical correlations between grain size, sorting and relative distance from beach/estuary have been recognized. Conclusion: Beach sands have been found coarser and well sorted with respect to the ones near estuary and upper tidal flat. Active sediment transport from estuary mouth by shore parallel current resulted in a mixing zone, resulting in poorly sorted sediment accumulation.]]> https://scialert.net/abstract/?doi=ajes.2020.37.44 10 June, 2026 Factors Determining Benthic Foraminiferal Distribution in the Shallow Water Coastal Environments of Southwest Nigeria Sector of the Gulf of Guinea Background and Objective: The dominant factors influencing abundance and distribution patterns of foraminifera in shallow water coastal environments of southwest Nigeria sector of the Gulf of Guinea was undertaken. The objectives were to characterize benthic foraminiferal population in sediments and establish relationships of the identified fauna with depth, salinity, pH, pollutant metals and sediment texture. Material and Methods: One hundred and thirteen surface-sediment samples were analyzed for common pollutant metal and foraminiferal contents and grain size composition. The depth of sediment-water interface, salinity and pH of water collected from selected stations were measured. Results: Organic matter enriched, dark-grey to black mud substrate enabled relatively large quantity of foraminifera at the Northwest portion of the lagoon despite the very low salinity that characterizes the micro-habitat. However, this habitat could only produce a monospecific assemblage whose total population is constituted by over 80% Ammonia beccarii. Few stations in Lagos Harbour were moderately polluted with Zn and are marked by low species diversity and abundance. Substrates seem to influence relative abundance of calcareous porcellaneous and agglutinated foraminifera at the Southwest and Eastern segments of Lagos Lagoon. Conclusion: Consequent upon the non-saline nature, specimens of foraminifera were not recovered from Badagry and Yewa creeks. Moderate pollution of sediments with Zn, Cd, Ni and Cr and the nature of substrates accounted for the disparity in foraminiferal species abundance, diversity and dominance in Lagos Lagoon. However, favourable pH, salinity and substrates facilitated high species variation and abundance in Lagos Harbour.]]> https://scialert.net/abstract/?doi=ajes.2020.45.68 10 June, 2026