@unilorin.edu.ng
University of Ilorin
Agricultural and Biological Sciences, Agronomy and Crop Science, Insect Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Olusegun Adebayo Ojumoola and Adebayo Amos Omoloye
Springer Science and Business Media LLC
Olusegun Adebayo OJUMOOLA and Adebayo Amos OMOLOYE
University of Ljubljana
The fall armyworm (Spodoptera frugiperda) is an invasive and highly destructive insect pest that has caused extensive damage to maize in Africa since its first report on the continent in 2016. Information on fall armyworm infestation and damage within African agroecologies is essential for the development of appropriate pest management strategies, but these are scant in Nigeria. Consequently, in this study, fall armyworm infestation levels and severity of damage to maize in the three major maize-growing agro-ecological zones (humid forest, derived savanna, and southern guinea savanna) of southwestern Nigeria was investigated using standard field sampling protocols. Results showed that maize infestation and damage severity varied across agroecological zones, with the humid forest being the most impacted. Information provided will enhance decision-making for effective management of the fall armyworm in southwestern Nigeria.
Olusegun Adebayo Ojumoola, Adebayo Amos Omoloye, and Vincent Chukwuemeka Umeh
Informa UK Limited
Olusegun Ojumoola, Hongze Ma, and Yongan Gu
MDPI AG
In this paper, gas pressure cycling (GPC) and solvent-assisted gas pressure cycling (SA-GPC) were developed as two new and effective enhanced oil recovery (EOR) processes. Eight coreflood tests were conducted by using a 2-D rectangular sandpacked physical model with a one or two-well configuration. More specifically, two cyclic solvent injection (CSI), three GPC, and three SA-GPC tests were conducted after the primary production, whose pressure was declined in steps from Pi = 3.0 MPa to Pf = 0.2 MPa. It was found that the CSI tests had poor performances because of the known CSI technical shortcomings and an additional technical issue of solvent trapping found in this study. Quick heavy oil viscosity regainment resulted in the solvent-trapping zone. In contrast, C3H8-GPC test at a pressure depletion step size of ∆PEOR = 0.5 MPa and C3H8-SA-CO2-GPC test at ∆PEOR = 1.0 MPa had the highest total heavy oil recovery factors (RFs) of 41.9% and 36.6% of the original oil-in-place (OOIP) among the two respective series of GPC and SA-GPC tests. The better performances of these two tests than C3H8- or CO2-CSI test were attributed to the effective displacement of the foamy oil toward the producer in the two-well configuration. Thus the back-and-forth movements of the foamy oil in CSI test in the one-well configuration were eliminated in these GPC and SA-GPC tests. Furthermore, C3H8-GPC test outperformed C3H8-SA-CO2-GPC test in terms of the heavy oil RF and cumulative gas-oil ratio (cGOR) because of the formation of stronger foamy-oil flow and the absence of CO2, which reduced the solubility of C3H8 in the heavy oil in the latter test. In summary, different solvent-based EOR processes were ranked based on the heavy oil RFs as follows: C3H8-GPC > C3H8-SA-CO2-GPC > CO2-GPC > C3H8-CSI > CO2-CSI.
Olusegun Ojumoola, Hongze Ma, and Yongan Gu
Elsevier BV