Papers by Sefunmi Obayan
The Nigerian oil and gas industry are expected to play an effective role in low carbon energy tra... more The Nigerian oil and gas industry are expected to play an effective role in low carbon energy transition (Edomah, 2019), since fossil fuels have the potential of remaining a vital component of the energy mix, in the nation (Nnaji, Chukwu and Nnaji, 2013; Elum and Momodu, 2017). Pledges are being made and supported by the leaders, and the core of these pledges is the need for transition from non-renewable fossil energy to a more sustainability energy source. the question has shifted from whether the oil and gas companies are part of the obstacles of energy transition or if they can be part of the solution, to how they can facilitate energy transition through innovation.
The hydrocarbon reservoir is a unique environment for the habitation of anaerobic microorganisms.... more The hydrocarbon reservoir is a unique environment for the habitation of anaerobic microorganisms. Drilling for oil can be quite challenging due to the uncertainties involved with hydrocarbon reservoirs. Some of the challenges involved in oil and gas drilling operations include; crude oil souring, fouling and corrosion among others. These problems could be of both biological and chemical origin. Autochthonous microorganisms (inhabiting the reservoir) in this environment account for a considerable extent of these problems, therefore their activities are economically important in the oil and gas sector. Methanogenesis and Sulphidogenesis are two of the well-documented microbial activities that affect the hydrocarbon reservoir.
Achieving effective and productive environmental performance of drilling fluid serves as a usefu... more Achieving effective and productive environmental performance of drilling fluid serves as a useful tool for improving environmental management systems and policy implementation strategies, health and safety, as well as reduce environmental damage and legal claims. Offshore drilling requires accurate mud technology, however even the most effective drilling fluid still has adverse effects on its immediate environment. The challenges in offshore drilling, makes it difficult to balance effective drilling with high environmental performance drilling systems. This challenge has triggered many researches globally leading to advancements in drilling fluid technology and substitution of the less effective ones. Different kinds of drilling fluids contains various chemical formulation which relatively affects drilling and environmental performance positively or negatively.
Thesis Chapters by Sefunmi Obayan
Oasis is an open cell plastic, which soaks up water like a sponge. The potential of the foam to f... more Oasis is an open cell plastic, which soaks up water like a sponge. The potential of the foam to filter, retain and sustain microbial live was examined using laboratory strains of Escherichia coli, Pseudomonads aeruginosa and Bacillus subtilis as well as the effluent strains of Micrococcus luteus, Bacillus cereus, Arthrobacter spp and Aspergillus nigar isolated from a newly modeled experimental rig. The water retention and evaporation rate of oasis floral foam was assessed by a wetting and weighing method. 8cm circular oasis foam 1cm deep was completely saturated by 3.915cm of water in the water retention experiment and 5.854cm water for 12cm by 8cm and 1cm deep, similarly the 8cm oasis foam, 1cm deep absorbed 60 ml of water which evaporated over a period of 6days with a 45.3% retention rate. This retention rate could mean steady moisture in this medium, which is an important factor for microbial growth. Microbial survival rate on the foam was determined by inoculating the wet and dry samples of the foam. The samples were left to dry for five days and representative samples were analyzed daily. M. luteus had the lowest survival rate while Arthrobacter spp was the most abundant and the growth of A. nigar was consistently low. Although the condition provided in the foam was limited, yet it was not apparently hostile for microbial growth, it has been shown that microbial growth in oasis foam is controlled not only by moisture content but also by aeration. The result indicated that the newly invented Oasis foam will provide additional benefit when incorporated in PPS, the properties of the foam is comparable to that of the natural environment and could be considered as a prospective substrate for bioremediation.
Bacteria were isolated from a stream with no history of LAS pollution and their responses to diff... more Bacteria were isolated from a stream with no history of LAS pollution and their responses to different concentration of LAS were investigated. Nine bacterial species, Burkholderia mallei, Escherichia coli, Micrococcus luteus, Proteus vulgaris, Pseudomonas putida, Pseudomonas stutzeri, Streptococcus faecalis, Bacillus subtilis and Bacillus cereus were isolated for the experiment, identified and categorised as LAS-sensitive bacteria, LAS-tolerant bacteria and LAS-degrading bacteria. The responses of the resident bacteria were assessed in terms of their ability or inability to grow in the presence of LAS and their possibility to degrade the surfactant. Two species, Pseudomonas putida, Pseudomonas stutzeri were tolerant of LAS (0.1% w/v) while seven were sensitive to LAS (0.1% w/v). The responses of the bacteria is useful in assessing water for the presence of LAS. The potential of some of the resident bacteria to degrade LAS can be explored with the aim of developing methods for wastewater treatment.
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Papers by Sefunmi Obayan
Thesis Chapters by Sefunmi Obayan