scholarly journals Structural interpretation of High-resolution aeromagnetic data over the Dahomey basin, Nigeria: implications for hydrocarbon prospectivity

2021 ◽  
Vol 11 (4) ◽  
pp. 1545-1558
Author(s):  
E. M Okoro ◽  
K. M Onuoha ◽  
C. G Okeugo ◽  
C. I. P. Dim
Keyword(s):  
High Resolution ◽  
Oil And Gas ◽  
Low Cost ◽  
Sedimentary Basins ◽  
Data Interpretation ◽  
Aeromagnetic Data ◽  
Horizontal Derivative ◽  
Dahomey Basin ◽  
First Vertical Derivative ◽  
Total Horizontal Derivative

AbstractThe renewed quest to boost Nigeria’s dwindling reserves through aggressive search for oil and gas deposits in Cretaceous sedimentary basins has re-ignited the need to re-evaluate the hydrocarbon potentials of the Dahomey Basin. Aeromagnetic data are a low-cost geophysical tool deployed in mapping regional basement structures and determination of basement depths and sedimentary thickness in frontier basin exploration. In this study, high-resolution aeromagnetic (HRAM) data covering the Dahomey Basin Nigeria have been interpreted to map the basement structural configuration and to identify mini-basins favorable for hydrocarbon prospectivity. The total magnetic intensity grid was reduced to the equator (RTE) and edge detection filters including first vertical derivative (FVD), total horizontal derivative (THDR), tilt derivative (TDR) and total horizontal derivative of upward continuation (THDR_UC)) were applied to the RTE grid to locate the edges and contacts of geological structures in the basin. Depth to magnetic sources were estimated using the source parameter imaging (SPI) method. Data interpretation results revealed shallow and deep-seated linear features trending in the NNE-SSW, NE-SW, NW-SE and WNW-ESE directions. The SPI map showed a rugged basement topography which depicted a horst-graben architecture on 2D forward models along some selected profiles. Two mini-basins ranging in basement depths between 4.5 – 6.3km were mapped offshore of the study area. It appears the offshore Dahomey Basin holds greater promises for hydrocarbon occurrence due to the presence of thicker succession of sedimentary deposits in the identified mini-basins.

scholarly journals INTERPRETATION OF MAJOR STRUCTURES WITHIN THE BASEMENT REGION OF BENUE-NIGER CONFLUENCE FROM AEROMAGNETIC AND RADIOMETRIC DATA KOGI STATE NIGERIA

2020 ◽  
Vol 5 (1) ◽  
pp. 17-22
Author(s):  
Fidelis I. Kwaghhua ◽  
Adetona Abbass A ◽  
Aliyu Shakirat B.
Keyword(s):  
Sedimentary Basins ◽  
Analytical Signal ◽  
Aeromagnetic Data ◽  
Data Set ◽  
Near Surface ◽  
North East ◽  
Depth Analysis ◽  
Magnetic Signatures ◽  
First Vertical Derivative ◽  
Radiometric Data

Interpretation of Aeromagnetic and Radiometric Data covering the basement region of Benue-Niger confluence was executed to delineate major structures and other geologic frame works of mineral interest. The study area which hosts the Benue-Niger confluence also encloses two major geologic units which are basement complex and sedimentary basins. The Aeromagnetic data set comprising sheet 227 (Koton-Karfe), 247 (Lokoja) and 267 (Idah) was enhanced to reveal geologic structures while radiometric data was analysed to map lithology and zones affected by hydrothermal alterations. A set of mathematical algorithms was used to enhance the data for interpretation. First Vertical derivatives, Analytical Signal and Euler deconvolution filters were applied to the Aeromagnetic data while Ratio and Ternary images of the three radiogenic elements were obtained for the radiometric data. Magnetic signatures from the TMI showed a mixture of high and low susceptibility below koton-karfe due to intrusion of oolitic iron ore within the sedimentary formation. Lokoja regions recorded highest susceptibility of 165 nT due to magnetic signatures emanating from exposed basement rocks. The southern Idah regions recorded relatively low susceptibility. Result of First Vertical Derivative revealed near surface mineral potent structures labelled F1 – F8, cringing surface features B1, B2 and B3. Analytical signal revealed high amplitudes range of 0.174 to 0.579 cycles for magnetic sources majorly at the basement regions, while low amplitude range of 0.021 to 0.157 cycles were recorded around the sedimentary regions. Euler depth analysis revealed shallower depth to sources in the basement and deeper depth to sources in the sedimentary regions due to thick overburden. Radiometric signatures from the K/Th ratio map revealed portions around Latitude 8°00’ NW and 7°30’ SW shaded in pink colour and having values above known threshold of 0.2 %/ppm to be hydrothermally altered. Mapping of lithology from Ternary map revealed K-Feldspar mineral bearing rocks dominated the NW and SW regions, while sandstones, ironstones, mudstones, shale, alluvium and other fluvial sedimentary lithologies dominated the sedimentary North-east and South-Eastern regions. The western regions (NW and SW) hosted the major structures in form of magnetic lineaments trending NE-SW and E-W which also coincided with regions delineated to be hydrothermally altered and apparently represents the most prospective regions of mineralisation in the study area.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Mathematical Substantiation of a New Electromagnetic Tool with Toroidal Coils for High-Resolution Logging of Oil and Gas Wells

2018 ◽  
Vol 16 (1) ◽  
pp. 113-129
Author(s):  
M. I. Epov ◽  
◽  
M. N. Nikitenko ◽  
V. N. Glinskikh ◽  
◽  
...  
Keyword(s):  
High Resolution ◽  
Oil And Gas ◽  
Gas Wells ◽  
Oil And Gas Wells

scholarly journals Fabrication and Compressive Behavior of a Micro-Lattice Composite by High Resolution DLP Stereolithography

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 785
Author(s):  
Chow Shing Shin ◽  
Yu Chia Chang
Keyword(s):  
High Resolution ◽  
Lattice Structure ◽  
Low Cost ◽  
Hierarchical Structures ◽  
Dip Coating ◽  
Unit Cell ◽  
Digital Light Processing ◽  
Unit Cell Size ◽  
Wide Range ◽  
And Performance

Lattice structures are superior to stochastic foams in mechanical properties and are finding increasing applications. Their properties can be tailored in a wide range through adjusting the design and dimensions of the unit cell, changing the constituent materials as well as forming into hierarchical structures. In order to achieve more levels of hierarchy, the dimensions of the fundamental lattice have to be small enough. Although lattice size of several microns can be fabricated using the two-photon polymerization technique, sophisticated and costly equipment is required. To balance cost and performance, a low-cost high resolution micro-stereolithographic system has been developed in this work based on a commercial digital light processing (DLP) projector. Unit cell lengths as small as 100 μm have been successfully fabricated. Decreasing the unit cell size from 150 to 100 μm increased the compressive stiffness by 26%. Different pretreatments to facilitate the electroless plating of nickel on the lattice structure have been attempted. A pretreatment of dip coating in a graphene suspension is the most successful and increased the strength and stiffness by 5.3 and 3.6 times, respectively. Even a very light and incomplete nickel plating in the interior has increase the structural stiffness and strength by more than twofold.

scholarly journals Deep Structure, Tectonics and Petroleum Potential of the Western Sector of the Russian Arctic

2021 ◽  
Vol 9 (3) ◽  
pp. 258
Author(s):  
Alexey S. Egorov ◽  
Oleg M. Prischepa ◽  
Yury V. Nefedov ◽  
Vladimir A. Kontorovich ◽  
Ilya Y. Vinokurov
Keyword(s):  
Oil And Gas ◽  
Deep Structure ◽  
Sedimentary Basins ◽  
The Arctic ◽  
Russian Arctic ◽  
Petroleum Potential ◽  
Western Sector ◽  
Gas Formation ◽  
Evolutionary Genetic ◽  
Tectonic Scheme

The evolutionary-genetic method, whereby modern sedimentary basins are interpreted as end-products of a long geological evolution of a system of conjugate palaeo-basins, enables the assessment of the petroleum potential of the Western sector of the Russian Arctic. Modern basins in this region contain relics of palaeo-basins of a certain tectonotype formed in varying geodynamic regimes. Petroleum potential estimates of the Western Arctic vary broadly—from 34.7 to more than 100 billion tons of oil equivalent with the share of liquid hydrocarbons from 5.3 to 13.4 billion tons of oil equivalent. At each stage of the development of palaeo-basins, favourable geological, geochemical and thermobaric conditions have emerged and determined the processes of oil and gas formation, migration, accumulation, and subsequent redistribution between different complexes. The most recent stage of basin formation is of crucial importance for the modern distribution of hydrocarbon accumulations. The primary evolutionary-genetic sequence associated with the oil and gas formation regime of a certain type is crucial for the assessment of petroleum potential. Tectonic schemes of individual crustal layers of the Western sector of the Russian Arctic have been compiled based on the interpretation of several seismic data sets. These schemes are accompanied by cross-sections of the Earth’s crust alongside reference geophysical profiles (geo-traverses). A tectonic scheme of the consolidated basement shows the location and nature of tectonic boundaries of cratons and platform plates with Grenvillian basement as well as Baikalian, Caledonian, Hercynian, and Early Cimmerian fold areas. Four groups of sedimentary basins are distinguished on the tectonic scheme of the platform cover according to the age of its formation: (1) Riphean-Mesozoic on the Early Precambrian basement; (2) Paleozoic-Cenozoic on the Baikalian and Grenvillian basements; (3) Late Paleozoic-Cenozoic on the Caledonian basement; (4) Mesozoic-Cenozoic, overlying a consolidated basement of different ages. Fragments of reference sections along geo-traverses illustrate features of the deep structure of the main geo-structures of the Arctic shelf and continental regions of polar Russia.

Earth's energy “Golden Zone”: a synthesis from mineralogical research

Clay Minerals ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 1-24 ◽  
Author(s):  
P. H. Nadeau
Keyword(s):  
Oil And Gas ◽  
Gulf Coast ◽  
Clay Mineralogy ◽  
Sedimentary Basins ◽  
Entrapment Efficiency ◽  
Permeability Evolution ◽  
Reservoir Temperature ◽  
Fundamental Particle ◽  
Geological Processes ◽  
The Impact

AbstractThe impact of diagenetic processes on petroleum entrapment and recovery efficiency has focused the vast majority of the world's conventional oil and gas resources into relatively narrow thermal intervals, which we call Earth's energy “Golden Zone”. Two key mineralogical research breakthroughs, mainly from the North Sea, underpinned this discovery. The first is the fundamental particle theory of clay mineralogy, which showed the importance of dissolution/precipitation mechanisms in the formation of diagenetic illitic clays with increasing depth and temperature. The second is the surface area precipitation-rate-controlled models for the formation of diagenetic cements, primarily quartz, in reservoirs. Understanding the impacts of these geological processes on permeability evolution, porosity loss, overpressure development, and fluid migration in the subsurface, lead to the realization that exploration and production risks are exponential functions of reservoir temperature. Global compilations of oil/gas reserves relative to reservoir temperature, including the US Gulf Coast, have verified the “Golden Zone” concept, as well as stimulated further research to determine in greater detail the geological/mineralogical controls on petroleum migration and entrapment efficiency within the Earth's sedimentary basins.

A HIGH-RESOLUTION 2D IMAGING LASER RADAR FOR OCCLUDED HARD TARGET VIEWING AND IDENTIFICATION

2008 ◽  
Vol 18 (02) ◽  
pp. 393-400 ◽  
Author(s):  
ROBERT J. GRASSO ◽  
JOHN C. WIKMAN ◽  
DAVID P. DROUIN ◽  
GEORGE F. DIPPEL ◽  
PAUL I. EGBERT
Keyword(s):  
High Resolution ◽  
Target Identification ◽  
Low Cost ◽  
System Size ◽  
Operating Conditions ◽  
Array Technology ◽  
Diode Pumped ◽  
Target Ranging ◽  
2D Imaging ◽  
Gated Imaging

BAE SYSTEMS has developed a Low Cost Targeting System (LCTS) consisting of a FLIR for target detection, laser-illuminated, gated imaging for target identification, laser rangefinder and designator, GPS positioning, and auto-tracking capability within a small compact system size. The system is based upon BAE Systems proven micro-bolometer passive LWIR camera coupled with Intevac's new EBAPS camera. A dual wavelength diode pumped laser provides eyesafe ranging and target illumination, as well as designation; a custom detector module senses the return pulse for target ranging and to set the range gates for the gated camera. Trials show that the current detectors offer complete extinction of signals outside of the gated range, thus, providing high resolution within the gated region. The images have shown high spatial resolution arising from the use of solid state focal plane array technology. Imagery has been collected in both the laboratory and the field to verify system performance during a variety of operating conditions.

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