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Aquifer hydraulic parameters including hydraulic conductivity and transmissivity play a very important role in the assessment and management of groundwater. Conventionally, these parameters are best estimated employing pump test, which is usually expensive and time-consuming. The use of surficial electrical resistivity data integrated with few available pumping test data provides a cost-effective and efficient alternative. A total of thirty-five (35) vertical electrical soundings with a maximum half-current electrode spacing of 150 m using the Schlumberger array were used in this study. Five (5) of these soundings were parametric soundings carried out in the vicinity of monitoring wells for correlation and comparative purposes. The empirical relationships between the hydraulic parameters derived from the pump test data and the aquifer resistivity data were established for the Ebonyi and Abakaliki Formations, respectively, and, in turn, used to estimate aquifer hydraulic parameters in areas away from wells. Aquifer hydraulic conductivity estimated across the study area varies from 0.49 to 1.5735 m/day with a mean value of 0.9205 m/day for the Ebonyi Formation, while the Abakaliki Formation has hydraulic conductivity values that vary from 0.0775 to 1.3023 m/day, with a mean value of 0.2883 m/day. The transmissivity values estimated across the study area range between 0.29 and 57.27 m2/day with a mean value of 6.59 m2/day. Transmissivity values obtained were interpreted with Krásný's transmissivity classification, and this delineated the study area into three groundwater potential zones: very low, low, and intermediate zones. The study shows that the areas underlain by the Ebonyi Formation have a higher groundwater potential than those underlain by the Abakaliki Formation. These findings are supported by the geology of the area, which revealed that the Abakaliki Formation is dominated by shales with very low permeability, while the Ebonyi Formation consists of shales with alternations of sand/sandstones, which statistical analysis of the different model equations used in estimating the hydraulic parameters of the study area revealed that the new model empirical equations proposed and used in the present study proved to be the best alternatives to pumping test data. [ABSTRACT FROM AUTHOR]

The challenges of reliably collecting, storing, organizing, and analyzing research data are critical in low- and middle-income countries (LMICs), particularly in Sub-Saharan Africa where several healthcare and biomedical research organizations have limited data infrastructure. The Research Electronic Data Capture (REDCap) System has been widely used by many institutions and hospitals in the USA for data collection, entry, and management and could help solve this problem. This study reports on the experiences, challenges, and lessons learned from establishing and applying REDCap for a large US-Nigeria research partnership that includes two sites in Nigeria, (the College of Medicine of the University of Lagos (CMUL) and Jos University Teaching Hospital (JUTH)) and Northwestern University (NU) in Chicago, Illinois in the United States. The largest challenges to this implementation were significant technical obstacles: the lack of REDCap-trained personnel, transient electrical power supply, and slow/ intermittent internet connectivity. However, asynchronous communication and on-site hands-on collaboration between the Nigerian sites and NU led to the successful installation and configuration of REDCap to meet the needs of the Nigerian sites. An example of one lesson learned is the use of Virtual Private Network (VPN) as a solution to poor internet connectivity at one of the sites, and its adoption is underway at the other. Virtual Private Servers (VPS) or shared online hosting were also evaluated and offer alternative solutions. Installing and using REDCap in LMIC institutions for research data management is feasible; however, planning for trained personnel and addressing electrical and internet infrastructural requirements are essential to optimize its use. Building this fundamental research capacity within LMICs across Africa could substantially enhance the potential for more cross-institutional and cross-country collaboration in future research endeavors. [ABSTRACT FROM AUTHOR]

3D geomechanical characterization of "Fuja" field reservoirs, Niger Delta, was carried out to evaluate the mechanical properties of the reservoir rock which will assist in reducing drilling and exploitation challenges faced by operators. Bulk density, sonic, and gamma-ray logs from four wells were integrated with 3D seismic data and core data from the area to estimate the elastic and inelastic rock properties, pore pressure, total vertical stress, as well as maximum and minimum horizontal stresses within the reservoirs from empirical equations, using Petrel and Microsoft Excel software. 3D geomechanical models of these rock properties and cross-plots showing the relationship between the elastic and inelastic properties were also generated. From the results, Young's modulus, bulk modulus, bulk compressibility, shear modulus, Poisson's ratio, and unconfined compressive strength recorded average values of 5.11 GPa, 5.10 GPa, 0.023 GPa−1 , 2.39 GPa, 0.39, and 39.0 GPa, respectively, in the sand, and 6.08 GPa, 6.09 Gpa, 0.016 GPa−1 2.84 GPa, 0.42, and 42.3 GPa, respectively, in shale, implying that the sand is less elastic and ductile and will deform before the shale under similar stress conditions. Results also revealed mean pore pressures of 13,248 psi and 15,220 psi in sand and shale units, respectively, mean total vertical stress of 28,193 psi, mean maximum horizontal stress of 26,237 psi, and mean minimum horizontal stress of 21,532 psi. From the geomechanical models, the rock elastic and inelastic parameters revealed higher values around the northeastern and parts of the eastern and western portions of the reservoir implying that mechanical rock deformation will be minimal in these sections of the field compared to other sections during drilling and post-drilling activities. The generated cross-plots indicate that a relationship exists between the elastic rock properties and unconfined compressive strength. Stress estimations within the reservoirs in relation to the obtained elastic and rock strength parameters show that the reservoirs are stable. These results will be invaluable in mitigating exploration and exploitation challenges. [ABSTRACT FROM AUTHOR]