http://ir.library.ui.edu.ng/handle/123456789/564 scholarly Wed, 08 Apr 2026 18:39:06 GMT 2026-04-08T18:39:06Z http://ir.library.ui.edu.ng/handle/123456789/9380 Title: Improving the rheological and filtration properties of an invert emulsion mud using a locally sourced modified polymer Authors: Akintola, S.A.; Sanusi, H.; Oyelola, C. Abstract: Drilling fluid is designed for easy to use, cost effective and environmentally friendly. Several studies have been carried out on the use of local materials such as starch as suitable substitute for imported additives. Due to this short coming resulting from the use of native starch, the potatoes starch was chemically modified using the process of graft copolymerization, before being investigated as an additive for treatment of invert emulsion drilling. Three mud samples labelled (Base fluid, Copolymer 1 and Copolymer 2) were prepared and diesel labelled Base fluid served as control. Varying concentration of additives (1.0 and 2.0 g) were used at added to the different mud samples and laboratory study was carried out using the API Recommended Practice at varying temperature. This study is aimed at improving the properties of an invert emulsion mud using chemically modified locally sourced pomoea batatas as additive Sat, 01 Jan 2022 00:00:00 GMT http://ir.library.ui.edu.ng/handle/123456789/9380 2022-01-01T00:00:00Z http://ir.library.ui.edu.ng/handle/123456789/9379 Title: Corrosion protection by novel conversion coatings on structural AI 6061 Authors: Oki, M.; Adediran, A. A.; Ikechukwu, A.; Onokohwomo, C. O.; Bosa, C.; Akintola, S. A.; Adesina, O. S. Abstract: Chromate conversion coatings have witnessed limited acceptability in recent times. The coatings contain Cr (VI) species that have been classified as environmental hazards and injurious to human. Thus, the use of environment-friendly and non-carcinigenic novel inorganic- inorganic hybrid conversion coatings are being explored. Vanadate (VCC), hybrid Vanadate/Molydate (HCC) conversion coatings on A16061 have been classified in terms of corrosion and adhesion performance with reference to the untreated alloy. Natural exposure tests in the atmosphere and stanant near-neutral 3.5% sodium chloride solution, as well as patentio-dynamic polarization measurements showed that the corrosion rate for HCC is lower for Vanadate, which in turn outclassed the ‘bare’ alloy. However, clusters of passive incipient pits were revealed on the former after 120 h of exposure in stagnant chloride solution. Both conversion coatings outperformed the untreated aluminiun alloy after atmospheric corrosion and adhesion tests. Sat, 01 Jan 2022 00:00:00 GMT http://ir.library.ui.edu.ng/handle/123456789/9379 2022-01-01T00:00:00Z http://ir.library.ui.edu.ng/handle/123456789/9378 Title: Investigation of the effect of some salts on the rheological properties of xanthan gum and gum arabic present in a drilling fluid Authors: Okaome, P.; Akintola, S. Abstract: The rheological properties of a drilling fluid are important because they allow for extensive examination of the viscosity, fluid flow profile, pressure loss, equivalent circulation density, and hole cleaning capability making it the foundation for all wellbore hydraulics. The viscosity, gel strength, and yield point of Gum Arabic and Xanthan Gum contained in a fresh water-based drilling fluid were investigated in the presence of three distinct salts: calcium chloride (CaCl2), potassium chloride (KCl), and sodium chloride (NaCl). The salts were introduced separately to three distinct fresh water-based drilling fluid samples in increasing weights. The Fann V-G viscometer was used for the required rheology properties measuring the RPM and gel strength. The plastic viscosity, apparent viscosity, and yield point were calculated from the experimental data. With increasing the salt concentration, the plastic viscosity, apparent viscosity, yield point, and gel strength all decreased, which was observed for all three salts used. This research aimed to investigate the effect of three different salts; Calcium chloride (CaCl2), Potassium Chloride (KCl), and Sodium Chloride (NaCl) on the rheological properties of Gum Arabic and Xanthan Gum viscosified water-based drilling fluid. Sat, 01 Jan 2022 00:00:00 GMT http://ir.library.ui.edu.ng/handle/123456789/9378 2022-01-01T00:00:00Z http://ir.library.ui.edu.ng/handle/123456789/9377 Title: Modeling the effect of modified local polymer on the rheological and filtration properties of water-based drilling fluid Authors: Akintola, A. S.; Adeniji, A. A.; Mogbolu, U. J. Abstract: In order to achieve a successful drilling operation, the drilling fluid used must be properly designed. Water based drilling muds that are formulated to suit drilling requirements include additives like clays for higher viscosity and starch for better filtration control properties. Locally available yams (Dioscorea) are a good source of starch, with good absorbent properties that give its good filtration control properties but poor gelling properties due to the easily soluble branched chained Amylopectin molecules which causes it to easily degrade. While mud samples treated with Carboxylmethyl cellulose (CMC) was used as control. Chemical modification of starch has been researched to be a good method of improving its gelling properties in water based mud which in turn improves the rheological properties of the mud. Cross linking agents like sodium acetate and ammonium phosphate are used to cross-link the Amylopectin and Amylose molecules in the starch thus making them less degradable. An experimental study was carried out to reduce the yams starch bio-degradable nature via chemical modification with some cross-linking agents (sodium acetate and ammonium phosphate). The results from the rheological and filtration control test carried out on the formulated mud samples treated with modified yams starch additive gave higher gel strength and yield point, exceptional shear thinning ability, lower plastic viscosity and a good but lower fluid loss control when compared to with the control samples. A Factorial design was developed to predict the rheological properties of the mud system at different temperatures and varying starch quantities. The results of the mud samples treated with the non-modified starches, modified yam starches and imported viscosifier (CMC) are indicators that the modified starches improved its gelling nature thereby giving the drilling mud a better rheological properties. Fri, 01 Oct 2021 00:00:00 GMT http://ir.library.ui.edu.ng/handle/123456789/9377 2021-10-01T00:00:00Z