IOSR-JAGG   Volume-9 ~ Issue-1 ~ Jan. – Feb. 2021

Abstract: The seismic noise analysis is very useful tool for characterizing the performance of the existing seismic stations and it should be used as a first step in reducing the noise level in seismic signals. The main indicator of the quality of a seismic station is the level of the noise recorded in the absence of seismic signal. The level of noise recorded on seismometer can be reduced by locating the station away from human activity, selecting good geology and ensuring good seismic vault design and constructed at site, including thermal insulation and excellent ground coupling of broadband seismometer. In the year 1998 an ice free, rocky area on Schimacher Oasis was selected to build the Indian second research station "Maitri" (70°45'52" S and 11°44'03" E) in East Antarctica. The seismic background noise is studied at Maitri broadband seismic station operated in continuous mode till date.......

Keywords: Seismic Noise Analysis, Maitri, human activity, Antarctica, Power Spectral Density (PSD), Probability Density Function (PDF).

Abstract: Foundation designs planning is very critical in engineering works, therefore geophysical investigation was carried out for foundation design of a proposed Dam at IyahGbede, Ijumu Local Government Area of Kogi State with a view to deduce and enhance the knowledge of the near subsurface integrity of the area for engineering structures.Electrical Resistivity method was adopted to conduct the survey for detail and distinct result. The aim of the exercise was to determine the soil properties of the subsoil layers that constitute the foundation soils and their competence as foundation soils for a dam site establishment. Traverse lines were established along E-W direction and six (6) Vertical Electrical Sounding points (VES) which is one dimensional in prospect, werelaid which to reveal the subsurface property of the area.The VES curves types are AA,AH, HA and KH,which depicts that the investigated site is competent for the proposed dam project.

Keywords: Electrical Resistivity Method, Dam Project, Foundation Design, Geophysical Investigation

Abstract: A geophysical survey, involving electrical resistivity imaging and magnetic method was carried out for evaluating the cause(s) of the three failed segments along Ikare – Ogbagi highway, southwestern Nigeria. A total of fifty - six magnetic data points, three dipole-dipole resistivity and nine Schlumberger vertical electrical sounding datasets were acquired along three traverses across the failed and stable portions of the road. Results showed two major magnetic responses; high and low zones identified as shallow basement/competent or high magnetized weathering resistant strata and weak zones/low weathering resistant strata respectively. High magnetic amplitudes were observed between 0 – 15 m / 25 - 30 m and low between 15 – 25 m / 30 - 100 m for traverse I; high between 40 -- 50 m with a peak at 45 m position and low between stations 0 - 40 m / 55 - 65 m....

Keywords: Geoelectrical, geological, highway, resistivity, stable, substrate

Abstract: The aim of this research is to estimate the aquifer protective capacity at Odo-Ona Elewe, Ibadan, Nigeria using electrical resistivity method. Ten Vertical Electrical Sounding (VES) data were acquired using Schlumberger Electrode Configuration, the VES Data obtained were interpreted using the Win resist software. The results were analyzed using Dar Zarook parameters and Geoelectric section to identify the aquifer zone of groundwater potentiality and to estimate the aquifer protective capacity of the area. The result of the apparent resistivity measurement and interpretation gave a four layered resistivity structure made up of a top soil, clay/sandy clay, sandy and fresh basement. This study has identified area with good groundwater potential and moderate aquifer protective capacity....

Keywords: Longitudinal Conductance, Transverse Resistance, Tranmisitivity, Aquifer Vulnerability, Vertical Electrical Sounding

Abstract: This study was conducted to evaluate the petrophysical parameter of the "Alpha Field" in Niger Delta, Nigeria using well log data. Four wells, namely Well 01, Well 02, Well 03, and Well 04 were studied using a suite of logs comprising of gamma-ray, resistivity, sonic, caliper, density, and neutron logs from the wells in the study area. Schlumberger's Petrel 2013 software was used to analyze the data. Quantitative properties including shale volume, porosity, permeability, water saturation, and hydrocarbon saturation were carried out using the well logs. Intervals with low Gamma-Ray reading relative to the Shale Baseline are interpreted as sand units. Based on this, five sand units, labeled as Dove, Saturn, Jasper, Mars, and Neptune were mapped between the depth of 5600ft and 7100ft across the four.....

Keywords: Alpha Oilfield, Hydrocarbon saturation, Niger Delta, Petrophysical Parameters, and Well Log Analysis.

Abstract: The study was carried out with the aim of interpreting the aeromagnetic data to delineate the sedimentary layer thickness over Northern part of Bida Basin for possible hydrocarbon potential. The study area is bounded by longitude 40 30' to 50 30' N and latitude 90 30' to 100 30'E with an estimated total area of 12100 km2 covering four (4) aeromagnetic sheets of Auna, Kontagora, Kainji and Fashe. The Total magnetic intensity(TMI) map was subjected to the regional-residual magnetic field separation using the upward continuation filter. Subsequently, the residual magnetic field anomaly map was subjected to the estimation of the sedimentary layer thickness using; the Spectral depth analysis, Source parameter imaging (SPI) and Euler deconvolution (ED) methods. However, the Spectral analysis revealed a maximum sedimentary thickness of 3.16 km, SPI method revealed a depth......

Keywords: Total magnetic intensity, Residual magnetic intensity, Sedimentary layer thickness, Spectral analysis, Source parameter imaging, Euler deconvolution and Hydrocarbon.

Abstract: The ultra-deep sandstone reservoirs of the Cretaceous Bashkiqike Formation in Kelasu structural belt are generally characterized by low resistivity, even lower than the regional standard water resistivity, which makes it more difficult to identify the reservoirs with medium and high resistivity. Therefore, through the comprehensive study of logging, seismic and core analysis data, the three-dimensional distribution characteristics of the low-resistivity gas stratum are clarified, and the low-resistivity gas stratum is divided into thick layer concentration type and thin layer dispersion type according to its development location, and the control factors of the two types of low-resistivity stratum are explored. The results show that the distribution of low-resistivity gas reservoirs is influenced......

Keywords: Low-resistivity gas stratum, Kelasu structural belt, Cretaceous Bashijiqike formation, Ultra-deep reservoir, Main controlling factor.