Advanced Reservoir Modeling and Fluid Flow Studies of Natural Gas Production from the Hydrate Reservoirs of the Alaska North Slope

The emerging possibility of the production of gas hydrates as an unconventional source of energy have spurred many objectives for research studies going on in this area. One of these is the U.S national hydrate research program with a primary goal of determining the tools and technologies for environmentally safe gas production from hydrate reservoirs. The work presented in this thesis is motivated by the need to provide reliable reservoir model-based predictions to support proposed long-term hydrate field production tests on the Alaska North Slope permafrost. While first order predictions have been made from reservoir models based on assumptions of homogeneity of properties, it has been shown that the degree of reservoir heterogeneity can significantly affect the quantitative and qualitative results.;This study is an advanced and robust evaluation of the gas production potential of hydrate reservoirs. The hydrate deposits within the region of Prudhoe Bay Unit (PBU) L-Pad and Mt. Elbert Well vicinity of the Milne Point Unit of the Alaska North Slope are primary subjects of investigation. It is an effort to build data-driven heterogeneous hydrate reservoir models by applying both conventional and novel methods of reservoir characterization to maximize the utilization of the available field data. Using well log data obtained from 78 L-Pad wells, geostatistical techniques were employed to obtain stochastic simulations of the 3D distribution of reservoir properties in the target hydrate units of the L-Pad region. Models for the Mt. Elbert deposit were developed by combining data obtained from well logs obtained during the 2007 Mt. Elbert stratigraphic test and a 3D seismic survey of the region. Additionally, wellbore flow assurance studies were coupled with reservoir models in order to predict potential production issues arising from the formation of secondary hydrates or ice within the wellbore fluids being produced under high pressure and low temperature conditions.;CMG STARS, a finite difference reservoir modeling software package, was used to solve the material and energy balance equations in which an equilibrium model of hydrate dissociation was used. The simulator also provides a means to couple artificial lift design of the wellbore with the reservoir model using established pressure drop-heat loss correlations. Gas and water production rates and the evolution of reservoir properties were extensively studied in varying production scenarios with depressurization as the primary recovery technique.;Predictions from 10 geostatistical realizations of the L-Pad model were within narrow ranges, which is an indication of the robustness and reliability of the model. Uncertainty assessment and sensitivity studies on the Mt. Elbert model showed that higher gas production rates were achieved in deeper (hence warmer) reservoirs and confirmed earlier studies that production from the Mt. Elbert prospect may too cold to be economically feasible. Furthermore, contrary to predictions from homogeneous models, the effect of secondary hydrate formation in the reservoir on gas flow was found to be very minimal. However, flow assurance and artificial lift design studies show that wellbore pressure and temperature conditions must be effectively managed to prevent formation of secondary hydrates or ice

Agriculture and Nation Building: Do Students Still Use the University Library? Case Study of University of Ibadan Agricultural Economics Graduate Students

The growing awareness of internet based information resources has made students to reduce their use of the physical library in which university has invested huge financial resources for nation building. Past research efforts on the use of library have mostly focused on the generality of students without localised study on a particular set of students. This paper therefore looked at whether graduate students of agricultural economics still use the physical library in the face of the growing efforts of promoting agricultural study and production in Nigeria. The factors that affect the length of time students spend in the library were also established. Simple random sampling was used to select 60 graduate students during the 2010/2011 academic session in Agricultural Economics Department, University of Ibadan. The students were administered with structured questionnaire and 57 were successful for analysis. Majority of the respondents were female while 47.37 per cent was single. Majority of the students visit the university, faculty department and outside library occasionally while 73.68 per cent are of full time mode of study. Almost all the students, 96.49 per cent use internet based library. The tobit regression revealed that full-time mode of study, increase in weekly financial allowance on study, membership of registered group off- and on-campus encourages students to spend more hours in the library. Full-time mode of study should be encouraged among the graduate students while the library should be equipped with adequate and reliable internet facilities and personal computers to encourage students’ visit and use of the library towards the promotion of agricultural scholarship for food sufficiency which is a valid aim of agricultural development and nation building. Keywords: Agricultural Economics, Graduate Students, Library Us

Determinants of Library Use Among Students of Agriculture: A Case Study of Lagos State Polytechnic

The study looked at the factors that affect agricultural students’ use of the library. Simple random sampling was used to select 145 students. The data were analyzed using the probit model. Age was found to have a negative effect on the use of the library by students. Alternative to library have negative significant effect while library use with friend, availability of relevant materials and hours spent in the library have significant positive effect on the library use. Positive Library staff response to students encourages students’ use of the library while the location of the library does not have negative effect on library use. It was then suggested library staff should periodically evaluate itself to encourage its response to students needs and the Polytechnic authority should ensure availability of relevant text books and materials in the library as few students have access to personal e-library and internet connection as library alternatives

Environmental Pollution in Urban Market: The Case of Bodija Market Ibadan, Nigeria.

Ibadan is one of the largest cities in Nigeria, whose rapid growth is yet to be followed with adequate planning aimed at preventing environmental pollution. Consequently, the challenges of living in a constantly polluted environment, associated with stench and discomfort resulting from this inadequacy remains a constant experience in Bodija Market (a leading food stuff market in Ibadan). The recurrence of these challenges and the examination of the methods of waste disposal adopted by sellers in Bodija, form the focus of this paper using the Health Belief Model and Social Action Theory as bases for explanation. The study also revealed illiteracy, ignorance, negligence and laziness as major predisposing factors that aided sellers dumping of refuse in the environment. Personal hygiene and attempts to keep their immediate surrounding clean were reported as strategies adopted for prevention of environmental pollution which was observed to be inadequate. As a result, most sellers were willing to pay reasonable fee to prevent dirty environment in order to avoid dire consequences. The study recommends improved government effort, education, sanctions, sensitization and campaign against environment pollution to rescue the situation. Key words: Environment, Pollution, Urban market, Education, Overpopulation, Refus

Stream Sediment Geochemistry of Telemu and its Environs: A Tool in Baseline Assessment of Mineralization Potential

Reconnaissance stream sediment geochemical studies were carried out in Telemu-Awo-Ede areas of Osun State to determine the concentrations and distribution patterns of trace elements. This was with a view to assessing the mineralization potential of the study area. Ninety six active stream sediments were collected from stream channels in Telemu-Awo-Ede. The samples were air-dried and sieved. One gram each of the minus 177 micron fraction was subjected to hot acid extraction with aqua regia (3 HCl: 1 HNO3) and perchloric acid (HClO4) in ratio 2:1. The aliquots were analyzed for Mo, Co, Cd, Ta, Cr, Cu, Fe, U, Th, Sc, Zn, Sr, La, Mn, Ni, Pb, Sn and Zn using the Buck 205 Atomic Absorption Spectrometer (AAS) interfaced with Graphite Furnace. The geochemical data was interpreted using both univariate and multivariate statistical methods. The element distribution and smoothed contour maps were plotted using ArcView-GIS and Geosoft Oasis Montaj Software, respectively. The results showed that only four (4) elements out of the eighteen (18) elements analyzed showed significant anomalous values. The anomalies of Sn, Sc, Ta, and Th were considered to be derived from primary mineralization of these elements. Those of Mn, Zn, Cd, and Fe are interpreted as being caused by secondary environmental controls, notably, precipitation of Mn-oxides in the soils and or anthropogenic contamination for Zn and Cd. Insignificant anomalies were observed from Ni, Cr, La, Mo, Pb, Cu Co, U, Sb and Sr. The study concluded that this area has Sc-Sn-Ta and Th mineralization potentials related to the pegmatoids. The results obtained from the geochemical studies confirmed the heterogeneous nature of the underlying rocks. Areas underlain by pegmatites and pegmatised schist coincide spatially with zones of relatively high values for U, Th, La, Sc, Sn and Ta; and are suspected to be mineralized in tin, scandium, thorium and tantalum. Keywords: Mineralisation potential, significant anomalies, insignificant anomalies, environmental controls.

Trace Metals and Hydraulic Characterization of Soils and Groundwater Around Ajakanga Dumpsite in Ibadan Metropolis, Southwest Nigeria.

Trace metals concentrations and hydraulic characteristics of soil were studied with a view to assessing the impact of the Ajakanga dumpsite in Ibadan, Southwest Nigeria, on soil and groundwater. Forty one surface soil samples were taken at the depth of 0.2 cm, eleven samples each of disturbed and undisturbed soils along two (2) vertical profiles at up-slope and down-slope pits within the dumpsite premises. Eight groundwater samples were also collected. Digestion of 0.5 gm each of fraction (< 63 µm) of the soil samples was carried out. Both the digested soil and groundwater samples were analysed for Zn, Cu, Mn, Pb, Cd, Ni, As, Co and Cr using Buck Model 205 Atomic Absorption Spectrophotometer (AAS). The undisturbed soils were used for the determination of hydraulic properties. The data collected were interpreted using appropriate qualitative and quantitative statistical techniques. Trace elements results for soil showed average values for Zn (29.30 ± 16.1 mg/L), Pb (14.72 ± 0.84 mg/L), Cd (2.49 ± 0.48 mg/L), Ni (2.03 ± 1.12 mg/L), As (0.84 ± 0.22 mg/L), Co (0.16 ± 0.10 mg/L) and Cr (0.92 ± 1.40 mg/L) that were higher than those of control site values suggesting contamination. Grain size analysis showed that the clay size particles average abundance was higher in the B-level of the down-slope soil profile with mean value of 5.07±0.82 % compared with mean value of 4.85 ± 0.59 % at the up-slope pit. Evaluated results showed that the B-level is more polluted than the A and C levels probably due to adsorbsion effect of clay-sized materials that are more abundant in the B-level. Groundwater trace elements average concentration values were Mn (0.31± 0.74), Pb (0.03 ± 0.04), Cd (0.02 ± 0.03 mg/L), As (0.06 ±0.03 mg/L) and Ni (0.13 ± 0.08mg/L) which were higher than the WHO (2007) permissible levels especially in samples taken close to the dumpsite. The study concluded that the soils and groundwater samples close to Ajakanga open dumpsites were more polluted than those taken far away. The soil contamination was well pronounced within 0 – 3.5 m of the vertical soil profile at the dumpsite vicinity. Keywords: Trace Metals, Soil, Groundwater, Hydraulic Characteristics, Dumpsite, Environmental Impact

Optimal Design and Cost Analysis of Hybrid Autonomous Distributed Generation System for a Critical Load

One of the universal targets of the United Nations Sustainable Development Goals is affordable and clean energy. It is on this premise that this study presents the integration of PV-wind distributed generation system into an existing diesel generator powered water treatment plant in a suburban town of Wudil, Nigeria. Inadequate and epileptic supply from the grid caused the dependence of the plant on the generator. The optimal design was determined using the Hybrid Optimization of Multiple Energy Resources (HOMER) software developed by the National Renewable Energy Laboratory. Simulation results produce an optimal hybrid system which includes photovoltaic (PV) panels, wind turbines, converter, batteries and a generator with a cost of energy of $0.26 at a renewable fraction of 95%. An analysis also demonstrates that implementing this design will result in low and fairly constant fuel price in the lifecycle of the project. This will, in turn, support sustainable economic development of communities served by the water treatment plant

Impact of working Capital Management on Financial Performance of Quoted Consumer Goods Manufacturing Firms in Nigeria

Working capital management is indispensable in strengthening firms’ liquidity position. A weak liquidity position poses a threat to the solvency of the company and makes it unsafe as well as unsound. The persistent winding up of most Nigerian manufacturing firms and the recent decline in the world oil price which significantly affected all the oil producing countries in the world of which Nigeria is not an exception demand for effective and efficient management of  resources to guarantee going concern.  This study examined the impact of working capital management on financial performance of quoted consumer goods manufacturing firms in Nigeria by specifically examined the impact of working capital management on return on assets and gross operating profit. The secondary data used were obtained from annual financial statements over a period of ten (10) years from 2005 to 2014 of purposively sampled fifteen (15) firms. Descriptive statistics were used to measure variations, statistical inferences were drawn using correlation and panel regression analysis was applied on performance and working capital management indicators to test the formulated hypotheses. The findings revealed that efficient working capital management increases financial performance. In conclusion, a negative relationship exists between Cash Conversion Cycle (CCC) and financial performance while there is a positive relationship between Average Collection Period (ACP) and financial performance. The study recommended that firms within the industry may increase their average collection period above the present industry average collection period of 58 days and proper analysis of working capital components should be constantly carried out to ensure that those critical areas for decision making process as it related to each of the performance measurement variables are identified and properly examined