IOSR-JAGG   Volume-2 ~ Issue-5 ~ SEP-OCT-2014

Abstract: Indravati "The lifeline of Bastar" is changing its course, in style and degree in a very short span of time which has invited attention of geo-scientists and policy makers to avoid any expected unpleasant circumstances .Here we have investigated the drainage rearrangement of Indravati river water, where , earlier, Jaura Nala( which used to flow northwards) connecting Kolab river and Indravati river acting as a feeder for Indravati, now flowing southward and draining the water of Indravati, has become a matter of serious concern for the sediment budgets and biotic distributions in the surroundings. Due to the stated changes, the likely hydro morphological impacts have also been discussed along with the possible measures to be adopted to avoid any disparity in future. A serious multidisciplinary probe into the possible causes ,the natural factors and human intervention, is warranted, taking in to account the considerations of changing surface topography including evidences derived from satellite and topographic data, understanding of geomorphological and sedimentological observations and impact due to man made structures like dams on the upstream side in Odisha.

Keywords: River capture, Indravati river, Chhattisgarh.

Abstract: The planned time to drill a geothermal well at Olkaria is sometimes exceeded by a big margin when down hole challenges are encountered whilst drilling. The geographical coordinates of Olkaria are 0o53'09"S and 36o16'12"E. The current drilling practice at the field is balanced pressure drilling. The common down hole problems encountered in the field are loss of circulation, well bore collapse, minimal Rate Of Penetration (ROP) and possible formation damage which consequently leads to reduced productivity of a well. It is evident that, the longer the drilling time, the higher the cost of the well. Underbalanced drilling is the application of drilling fluids to the bore at a pressure slightly lesser than the formation fluids pressure. If the process is well executed, it may lead to the reduction/elimination of most down hole challenges. This research was geared to establishing the effectiveness of Under Balanced Drilling (UBD) in solving the down hole problems experienced at the Olkaria geothermal field. In order to carry out this exercise, simulation of under balanced drilling conditions using the Hydraulic Underbalanced Simulator (HUBS) was done utilizing data from the field. Secondly, the economics of adopting under balanced drilling technology at the field was also done. Data from four geothermal wells namely OW 731A, OW915B, OW731 and OW804 was used in the simulation exercise. Analysis of loss of circulation to well productivity for a sample of 19 wells was also undertaken. Simulated annulus volume fraction profiles showed cuttings concentration of less than 5% and an optimum circulation flow rate of 0.03 m3/min. The costs associated with loss of circulation of drilling fluids on average amounts to USD 127,731.00. Most of the wells sampled had over 70% of the drilled depth experienced no loss of circulation during drilling. Wells which had a circulation regime of full returns, partial returns and no returns have shown that their productivity is higher compared to the other categories and had an average production capacity of 12.03 Mw

Keywords: Underbalanced drilling, Formation damage, Rate of penetration, Loss of circulation and down hole challenges.

Abstract: The friable quartzite zone near Barodia in Bundi district of Rajasthan has been met with almost continuously for a distance of about 1,400 yards in a general E-W direction. It is developed along the slopes of a chain of quartzite ridges, near the base of the lower Bhander quartzites. The width of this zone as measured on a horizontal plane varies from 50 to 300 feet. The depth of the friable zone is not known and could not be determined. The friable rock, however, has been met upto a depth of 25 feet in the existing workings and can be reasonably assumed to extend up to a depth of at least 50 feet. The good plantation indicates eco-friendly mining activity in the mine site of silica sand mining.

Key words: Silica-sand,Great Boundary Fault, Eco-friendly Mining etc.

Abstract: The Benue basin is a major geological formation underlying a large part of Nigeria. It is a part of the broader Central African rift system. The Upper Benue basin being part of Benue basin is believed to be rift valley and is expected to be a major depositional basin, because rifting structures are often good sites for mineralization. The strategic economic importance and the availability of data from the study area arose the interest of many researchers including this present work to focus their attention on the area in search of geological features that are favourable to mineral deposition in the basin. The area investigated covers from 07000' - 080 30'N and from 110 00' - 120 00'E. In this work, the interpretation of the data extracted from the aeromagnetic maps of the basin was carried out using automated techniques involving the analytic signal, horizontal gradient magnitude and the log power spectrum techniques to delineate linear geologic structures such as faults, contacts, joints and fractures within the study area in a bid to unravel the gross sub surface geology of the area which would in no doubt help in better understanding and characterization of the area investigated. The residual magnetic field was subjected to three filtering techniques, the analytic signal, horizontal gradient method and the log power spectrum. A grid of analytic signal technique was employed to study source parameters which include location, depth and susceptibility contrast of identified magnetic anomalies in the basement rocks. The horizontal gradient method was used to study the fault and contact pattern in the study area while Power spectrum technique was also used to further study the depth estimates to the magnetic basement.

Keywords: Aeromagnetic map, Analytic signal, Log power spectrum, Magnetic mineral, Rift valley, Upper Benue basin

Abstract: For the security reasons, buried weapons need to be detected. This study explains laboratory experiments of using the Ground Penetrating Radar (GPR) to study the feasibility and ability of this technique to detect these subsurface caches and calculate the target depth and dimensions. Iron, plastic, wooden boxes filled with metallic materials, and empty plastic box buried in the sand box had been used as examples of the weapons caches. The GPR system had been run over these materials with 1500MHz GSSI antenna. The GPR data indicate that all the four cases are predictable and investigated by this non-destructive geophysical tool. Also, the distinctions between the different weapons containers and the filled or empty boxes are easy to be investigated by the GPR system.

Keywords: Ground Penetrating Radar, Antenna, Dielectric constant, Caches, Electromagnetic waves.

Abstract: The aim of this paper is to prove that the reflection seismic method available to image the water table reflection. It is to response Clement et al (1997) statement that "Seismic refraction is the only technique to image the water table". Two sets of seismic records from a difference subsequent field survey have been processed using the similar processing sequences. Both of them image a clear reflector. Edwinstow seismic record presented the water table reflector while the other is Croft set of record that presented the lithological reflector. The application of AVO analysis to CMP gathers from Edwinstow field records shows the characteristic of increase sharply amplitude with increasing angle of incidence for second critical reflection. On the other hand, the characteristic of decreasing amplitude with increasing angle of incidence for second critical reflection was presented by Croft field records. In this way the water table reflector is clearly distinguished oppositely from lithological boundaries. The results of both field survey and its interpretation are validated by equipment asessments that includes: seismograph, Promax processing system, and geophones test. Keywords: geophysics, water table, shallow, seismic, reflection, AVO.

Abstract: A set of 2-D seismic reflection data from New Zealand was used as a part of this seismic processing procedure. It was known that, at this region a set of petroliferous reservoir situated in an anastomosing faults were present. The objective of this seismic processing is to create an image of the substructure beneath a fault zone known as the Alpha fault zone. The processing involves in removing refractions and direct arrivals, applying true amplitude recovery; correction to account for seismic energy decay and applying a noise filter to remove the random noise recorded whilst data acquisition. At the preliminary stage, a filtered unstacked seismic data was obtained. It is clear that more advanced processing of the seismic data needs to be done to improve the signal-to-noise ratio of the seismic data. In the final processing sequence (migration) an accurate velocity field is obtained for generating the subsurface image. Dip Move out (DMO) and post-stack time migration are the processes which were applied to the APH-434 dataset. A processing workflow has been outlined in this report for future testing and signal analysis of the seismic data.

Keywords: 2-D seismic reflection data,seismic processing, signal-to-noise, Alpha fault)

Abstract: Geotechnical characterization of samples of three lateritic sub-base soils along Ibadan-Oyo highway was executed to establish the variability in properties of the soils. Parameters often used in the evaluation of highway sub-base soils, such as consistency (Atterberg) limits, Grain size distribution, Specific Gravity, California Bearing Ratio (CBR), permeability were considered. The determined Geotechnical properties of the tested soils varied from one location to the other along the highway. Laboratory analyses showed that some parameters such as maximum Dry Density the amount of fines and the unsoaked CBR exhibit high variability while others such as specific gravity, optimum moisture content ( OMC) and permeability have low coefficient of variation

Abstract: The ionospheric parameters, strongly dependent on the solar conditions and on the complex behavior of the magnetosphere, are very interesting for studying the complex phenomena and high degree of space time variability of the ionosphere occurring at the high latitude regions. In order to see the behavior of the high latitude ionosphere during the geomagnetically active events of extreme minimum phase of solar cycle 23 and starting phase of 24th solar cycle, in April 2010 moderate geomagnetic storms have been identified and represented in fairly well detail in the present investigation. The ionospheric observations have been obtained from dual frequency GPS, installed and operated at Indian scientific base station Maitri (71.450S and 11.450E) Antarctica, during December. 2009 to December 2010. Situated on auroral region mainly two parameters from the GPS observations, (I) Total Electron Content (TEC), (II) Total Electron Content Rate (TECR) have been considered for the present study. On storm days, the percentage deviations of TEC from geomagnetically quiet days at high latitudes shows the variations of ionosphere in terms of positive and negative ionospheric storms. The results therefore showed the dependence of occurrence characteristics of TEC on the solar activity.

Keywords: Geomagnetic Storm, TEC, High latitude ionosphere

Abstract: Palynological and hydrocarbon potential of Eocene Nanka Formation was investigated from subsurface shale sample recovered between the depth 17 to 28 meters at Agulu Lake south eastern Nigeria. The Rock-eval pyrolysis results recorded shows that Total organic carbon (0.40), S1 (0.03) and S2 (0.23) of the analyzed sample has a petroleum potential that is poor in quality. Production Index (0.10) and Tmax (412) records indicates that the stage of thermal maturity for its oil is mature. Hydrocarbon Index (58) and Oxygen Index (101) results suggest a Type IV Kerogen. The kerogen investigation indicates that particulate organic matter, spore and pollen colouration and vitrinite reflectance results obtained from the simple is at an immature thermal oil maturity stage. The age-diagnostic index palynomorphs species recovered assigned a Middle-Eocene for the studied area. The results suggests that Agulu lake, which is mid-Eocene has a hydrocarbon record of type IV kerogen, immature stage of thermal maturity, poor source bed, but has organic matter that may generate oil.

Keywords: Nanka Formation, Anambra Basin, Agulu Lake, Rock-eval Pyrolysis, Kerogen and Palynomorphs

Abstract: An inorganic geochemical study of a clay and shale sediments sequence around Araromi and Irogun-akere (the Southern part of Yewa River), Eastern dahomey basin, south western Nigeria, was carried out to determine the sediment's depositional conditions, provenance and tectonics. Fifteen shale and clay sediment samples underwent mineralogical and geochemical analysis involving major, trace and rare earth element analysis at acme analytic laboratory, Ontario, Canada using an ICP mass spectrometer (Perkin-Elmer, Elan 6000). Mineralogical studies using X-ray diffraction analysis revealed prominent kaolinite, montmorillonite and illite peaks; accessory minerals included quartz and microcline. Major element abundance showed that the shale samples consist of SiO2 (44.77%), Al2O3 (15.01%) and Fe2O3 (5.75%), constituting more than 65% of bulk chemical composition. Thirty-four elements trace metals; heavy rare earth elements and light rare earth elements analysis were quantified from the geochemical analysis. The shale sediments exhibit higher Ni, Ba, CO, Zr, Rb and Th concentrations than clay sediments, whereas clay samples are Sr-, Zn,, Pb- and U-enriched .Light rare earth element (La, Ce, Nd,Sm,Pr) were enrich in shale and clay sediment samples while, heavy rare earth elements (Tb, Yb, Lu, Gd ,Dy ,Ho, TM and Eu) are depleted. High TiO2 and Rb/K2O values also indicated that the shale and clay samples were matured. Geochemical parameters such as U, U/Th, Ni/Co and Cu/Zn ratios indicated that these shales were deposited in oxic conditions; the Al2O3/TiO2 ratio suggested that intermediate igneous rocks were probable source rocks for the shale, while mafic rocks were suggested as being source rocks for the claystone. However, the La/Sc, Th/Sc, Th/Co ratios and shale and clay sediment plots revealed that they came within the range given for felsic rocks as provenance, thereby suggesting mixed provenance for the sediments. A passive-margin tectonic setting was adduced for the sedimentary sequences.

Keywords: Trace metals,Light Rare Earth Element, Heavy Rare Earth Element, Inductively coupled mass spectrometer, X-ray diffraction analysis, provenance, tectonic setting

Abstract: The Exploration complex geological structures like crystalline basement, significant to hydrocarbon exploration, is complicated in seismic interpretation. Gravity data were analyzed at a Guelb Ahmer horst situated to northern border of Ghadames basin (Southern Tunisia). The average radial spectrum from an area of 40x40 km of the gravity data grid reveals the deep and intermediate basement sources depths. 3D Euler deconvolution technique illustrates also the limits of the crystalline basement sources running essentially between 2000 and 3000 meter deep. The geometries of Mesozoic rocks, Paleozoic strata and Precambrian basement rocks are estimated by five 3D gravity models. These models give a significant support for the determination of potential structural traps related to the Guelb Ahmer horst.
Keywords: Basement, Depth, Ghadames, Gravity, Tunisia

Abstract: Often, much attention is paid to things that do not majorly "sustain life" while the main pre requisite to living is usually left unattended to. Geoscience has been a tool used in solving the Earth's challenges both directly and indirectly. For instance, mining processes as well as hydrocarbon exploration has been aided extensively by the application of Geoscience, whereas Geophysics as a branch of Geoscience, which has proven worthwhile with so much importance in solving societal major need – Agriculture, is not gaining much attention.For agricultural application of geophysical methods, the three of all methods predominantly used are Electrical resistivity, Electromagnetic induction, and Ground Penetrating Radar (GPR). All these three methods are active, requiring artificial application of energy.Electrical resistivity method measures the electrical resistance for a bulk volume of soil which lies beneath the surface.