Papers by Onengiyeofori A . Davies
World Journal of Advanced Research and Reviews, 2026
This study presents a Python-based workflow for seismic-to-well tying, reservoir correlation, and... more This study presents a Python-based workflow for seismic-to-well tying, reservoir correlation, and structural mapping using well-log and 3D seismic data from the Kolo Creek Field in the Niger Delta Basin. The study aimed to evaluate the applicability of open-source scientific computing tools for seismic interpretation and reservoir characterization traditionally performed using proprietary software. Gamma ray, resistivity, sonic, and density logs were integrated with 3D seismic data for reservoir identification, synthetic seismogram generation, seismic-to-well tying, horizon interpretation, and structural mapping. Acoustic impedance and reflection coefficient series were computed from the sonic and density logs, after which synthetic seismograms were generated using a 25𝐻𝑧 zero-phase Ricker wavelet. The results revealed laterally continuous reservoir intervals with depths ranging from 11,598𝑓𝑡 to 12,248𝑓𝑡 across the study area. Seismic-to-well tying identified the reservoir top at approximately 978.87𝑚𝑠 two-way travel time and produced a calibrated average interval velocity of approximately 24,016𝑓𝑡/𝑠 for depth conversion. The generated time and depth structure maps revealed a regional structural dip with localized structural closures that may represent favorable hydrocarbon trapping configurations. Comparison between the Python-derived depth structure map and a previously published Petrel-derived interpretation showed strong agreement in structural trends and contour geometry. The study demonstrates that Python-based workflows provide a reliable, reproducible, and cost-effective framework for seismic interpretation, structural mapping, and reservoir characterization within academic and research environments.
Journal of Applied Geology and Geophysics, 2026
An integrated analysis of core-derived facies and well-log petrophysical data was carried out to ... more An integrated analysis of core-derived facies and well-log petrophysical data was carried out to characterize the reservoir architecture of the GABO Field in the onshore Niger Delta Basin. Detailed core descriptions were used to identify lithofacies based on grain size, lithology, and sedimentary structures. Six lithofacies were recognized, including trough cross-bedded sandstone, planar cross-bedded sandstone, ripple-laminated sandstone, horizontally laminated sandstone, heterolithic sand-mud facies, and laminated mudstone. These facies reflect a range of depositional processes from high-energy traction currents to low-energy suspension settling. Well-log correlation across the three wells (GABO-12, GABO-13, and GABO-20) used for the study reveals twelve laterally correlatable reservoir zones (A1-A12) characterized by low gamma-ray responses and relatively high resistivity signatures typical of clean sandstone reservoirs. Although these reservoirs display overall lateral continuity, variations in thickness and shale content suggest facies-controlled heterogeneity within the field. Petrophysical evaluation of the correlated reservoir zones in the three wells indicates that the reservoir sandstones exhibit generally favorable properties, with porosity values ranging from approximately 0.24 to 0.33 and permeability values varying from about 130 mD to more than 1100 mD. Hydrocarbon saturation values reaching up to about 0.97 indicate the presence of productive hydrocarbon-bearing intervals. The integrated results indicate that the reservoirs were deposited within a tidally influenced deltaic system characterized by stacked sandstone bodies separated by shale layers that act as vertical seals or internal flow barriers. This study demonstrates that combining core sedimentology with petrophysical analysis and well-log correlation provides a more reliable understanding of reservoir architecture and heterogeneity in complex deltaic systems such as the Niger Delta Basin.
JENER Journal of Empirical and Non-Empirical Research , 2026
This study examines the layer-dependent scaling between propagation an gle and oscillation period... more This study examines the layer-dependent scaling between propagation an gle and oscillation period of Alfvén waves in a gravitationally stratified solar atmosphere using a linearized ideal magnetohydrodynamic (MHD) framework. A dispersion relation is derived and evaluated for plasma conditions representative of the photosphere , chromosphere, and corona, and the propagation angle is computed as a function of oscillation period across these layers. The results show that the angle-period relationship follows an arctangent scaling of the form , where the scaling parameter depends on the Alfvén speed and plasma properties. This scaling captures a clear transition in wave behaviour with height. In the lower atmospheric layers, where , the propagation angle varies approximately linearly with oscillation period, indicating strong coupling. In the chromosphere, a transitional regime () is observed, where the dependence weakens. In the corona, where , the propagation angle approaches , indicating saturation and predominantly transverse propagation. These results show that gravitational stratification governs the scaling through its influence on the parameter and provide a quantitative description of how wave propagation geometry and energy transport evolve across the solar atmosphere.
Measures of Day and Night Times Ozone (O3) Concentration in Parts of Port Harcourt, Rivers State, Nigeria
International Journal of Research and Scientific Innovation
This work was aimed at taking measures of ozone concentration during day and night times in Port ... more This work was aimed at taking measures of ozone concentration during day and night times in Port Harcourt. To this end, we employed a smart unmanned aerial vehicle (UAV) that we had previously designed and constructed to take measures of atmospheric zone concentration in mg/m3. We collected data, in 5-minutes intervals, at noon for 245 minutes within 1pm-3:45pm and at night for 180minutes within 8pm-10pm on the 18/11/2022 on our pilot launch. The data collected was determined by how long our device battery could last on the pilot launch. Our results from the day time measures of ozone concentration showed that the concentration of ozone was quite stable, remaining between 0.1 and 0.2 mg/m3 the whole period while the night time observation shows a natural rise in ozone levels throughout this time period, with concentrations ranging from 0.03 to 0.06 mg/m3. This shows that the ozone concentration was higher during the night time, which could be attributed to Port Harcourt being an urb...
Estimates of the Wetting-Phase Relative Permeabilities of a Typical Reservoir Rock in the Niger Delta Using Well Logs: Kolo Creek as Case Study
Social Science Research Network, 2019
Evaluation of Environmental Impact of Dolerite Mining in Nigeria (Suspended Particulate Matter and Heavy Metal Concentrations)
GeologyRN: Mining Geology & Engineering (Topic), 2018
The Source Sampling of Particulate Matter (PM) of heavy metal distribution in dolerite mining sit... more The Source Sampling of Particulate Matter (PM) of heavy metal distribution in dolerite mining site, Uturu, Abia State, was investigated using a High-Volume Sampler method. The Suspended Particulate Matter (SPM) concentrations was reported to be 2542.6, 2507.1, 2213.4, 2153.3, 3306.8, and 20.5 μg/m<sup>3</sup> which was mostly higher than the limits of 200 and 50 μg/m<sup>3</sup> set by NESREA [10] and WHO [17] respectively in most locations around the quarry site, there were regions where the values were considerably lower than these standard limits. Specifically, results obtained in the areas such as Behind Crushing Zone, Office 1, Generator House, Office 2 and Crushing Zone were markedly above the control (26.8µg/m<sup>3</sup>).
International Journal of Terrestrial Heat Flow and Applications, 2021
A study of the effect of near-surface temperature on fields of subsurface geothermal gradient and... more A study of the effect of near-surface temperature on fields of subsurface geothermal gradient and heat flow has been carried out in the Bornu-Chad Basin, Nigeria, using corrected Bottom-Hole Temperatures (BHTc) lithologic-log data from 9 oil wells. The geothermal gradient using only BHTs ranges from 15.9oCkm-1 to 38.2oCkm-1 with an average of 26.9+/-3.5oCkm-1, while that computed with mean annual temperature and BHTs ranges from 28.2oCkm-1 to 51.5oCkm-1with an average of 37.5+/-2.5oCkm-1. The geothermal gradient using the mean annual temperature and BHTs in the Bornu-Chad is higher than using only BHTs by 7.0oCkm-1. Heatflow ranges from a minimum of 61 mWm-2 to a maximum of 114mWm-2 with an average of 68+/-5.89mWm-2. The isotherm maps exhibit an increasing SW-NE trend. An average heat flow of 68+/-5.9mWm-2 deduced from Bornu-Chad basin is normal for a continental passive margin with age of about 100My. Geothermal gradient results show a distinct and direct relationship with near-sur...
Earth Science Malaysia, 2020
A total of sixteen Vertical Electrical Sounding (VES) surveys and five physicochemical analyses w... more A total of sixteen Vertical Electrical Sounding (VES) surveys and five physicochemical analyses were carried out in selected locations within the Yenagoa Metropolis, in Bayelsa State, Nigeria, to delineate the concentration of ferruginous minerals in freshwater aquifers in the area. For the geophysical survey, the Schlumberger electrode configuration was employed. The resulting data obtained was processed and interpreted using Excel suite, IPI2WIN resistivity, Surfer-11 and Rockworks software. The results revealed four to six geologic layers across the area, and were used to generate geoelectric maps which showed that in most part of the study area, there were uneven distributions of shallow aquifers (4 – 10m), and uneven layers of clay and sandy-silt at varying depths up to 20m. The physicochemical analysis of raw water samples collected from five boreholes located in close proximity to the VES sounding locations were analysed for physical and chemical parameters. Physical paramete...
SSRN Electronic Journal, 2019
Aimed at determining a more reliable method of estimating permeability from well log data, in the... more Aimed at determining a more reliable method of estimating permeability from well log data, in the absence of core data, 4 predictive empirical models for estimating permeabilities (RGPZ model, Van Baaren’s model, Timur’s model and Berg’s model) were applied to two different reservoirs in a single well from an oil field in the Niger Delta. With the models employed at different cementation factors (m=1.5, 1.65, 1.80, 1.95, 2.10, 2.25, 2.40, 2.55, 2.70, 2.85, 3.00), using well log data from the reservoirs of interest, as a function of depth, measures of normalized root mean square error (NRMSE), relative to permeabilities measured from core analysis at the same reservoir interval, were used to determine which predictive model was more reliable. Obtained results showed the most reliable predictive model at m=1.65. At this cementation factor, the NRMSE for RGPZ model, Van Baaren’s model, Timur’s model and Berg’s model were 4.95, 30.38, 1.85, and 1.20 respectively in the first reservoir and 4.28, 24.69, 1.56 and 1.09 respectively in the second reservoir. Hence, Van Baaren’s model provided a more reliable measure of in-situ permeabilities in the reservoirs of the Niger delta as it had a lower measure of NRMSE in the reservoirs of interest.
Social Science Research Network, Feb 1, 2019
As the erratic nature of the cellular network services in Nigeria become increasingly worrisome, ... more As the erratic nature of the cellular network services in Nigeria become increasingly worrisome, the signal strengths and qualities of four (4) available cellular networks operating in Ogoni, South-South Nigeria are compared to ascertain the network with a better signal strength and quality. Measurement of signal strength () and quality of signal () at one-hour intervals were made for the four networks using a GSM signal monitor, version 3.24 for android (a software to monitor and analyse the received signal strength index (RSSI) and quality of signal of the cellular networks). Results showed that the network with the highest values of signal strength has the best quality of service. The average mean signal strengths for the four networks obtained were of −86.25 / , −86.33 / , 86.71 / and −86.42 / for MTN Nigeria, Airtel, Globacom and Etisalat (9Mobile) respectively. Also, the average mean quality of signal for the four networks obtained were 43.38%, 43.33%, 43.25% and 43.25% for MTN Nigeria, Airtel, Globacom and 9Mobile respectively. The study also showed that fluctuations in signal strength and quality of the cellular networks of interest were more profound during the off-peak hours of the day. Therefore, MTN was thought of as providing a better cellular network service in Ogoni as it had better signal strength and better quality of signal throughout the period of caring out this research.
Estimates of Permeabilities of Niger Delta Using Well Logs
Aimed at meeting the needs of reservoir simulation, estimates of the wetting phase relative perme... more Aimed at meeting the needs of reservoir simulation, estimates of the wetting phase relative permeability for a sandstone reservoir in the Niger Delta region were made by analysing variables obtained from well logs. Analysis was carried out for two reservoirs (RESERVOIR I and RESERVOIR II), one shallower than the other, within the study area by applying an empirical model (that related relative permeability to fractional water saturation and saturation exponent) to resistivity data obtained from the available well logs. The results showed that the wetting phase relative permeability had estimated values ranging from 0.000 to 0.113 and 0.000 to 0.202, for RESERVOIRS I and II respectively. Further analysis showed that the estimated wetting phase relative permeability was affected by the wettability and pore structure of the reservoirs of interest.
Comparative Analysis of Porosity Estimates in a Sandstone Reservoir: The Niger Delta as Case Study
GeographyRN: Environmental Security (Sub-Topic), 2018
Sonic logs and density logs – derived porosities was estimated from two different reservoirs in a... more Sonic logs and density logs – derived porosities was estimated from two different reservoirs in a single well and comparatively analyzed in this study. The well log is taken from an oil field in the Niger Delta. The study is aimed at identifying a more statistically dependable method, relative to the methods described herewith, in estimating porosity values in the Niger Delta Basin. The well was logged for Transit times, bulk density of the formation and porosity from core analysis as a function of depth. Measures of normalized root mean square error (NRMSE), relative to porosities measured from core analysis at the reservoir intervals, and coefficient of variation were employed in determining which of the estimates were more reliable. For RESERVOIR I, the NRMSE for sonic logs-derived porosites and density logs – derived porosities were 17.96% and 18.68% respectively. For RESERVOIR II, the NRMSE for sonic logs-derived porosites and density logs – derived porosities were 17.35% and 1...
Estimates of Permeabilities of Niger Delta Using Well Logs
Aimed at meeting the needs of reservoir simulation, estimates of the wetting phase relative perme... more Aimed at meeting the needs of reservoir simulation, estimates of the wetting phase relative permeability for a sandstone reservoir in the Niger Delta region were made by analysing variables obtained from well logs. Analysis was carried out for two reservoirs (RESERVOIR I and RESERVOIR II), one shallower than the other, within the study area by applying an empirical model (that related relative permeability to fractional water saturation and saturation exponent) to resistivity data obtained from the available well logs. The results showed that the wetting phase relative permeability had estimated values ranging from 0.000 to 0.113 and 0.000 to 0.202, for RESERVOIRS I and II respectively. Further analysis showed that the estimated wetting phase relative permeability was affected by the wettability and pore structure of the reservoirs of interest.
Comparative Analysis of Porosity Estimates in a Sandstone Reservoir: The Niger Delta as Case Study
GeographyRN: Environmental Security (Sub-Topic), 2018
Sonic logs and density logs – derived porosities was estimated from two different reservoirs in a... more Sonic logs and density logs – derived porosities was estimated from two different reservoirs in a single well and comparatively analyzed in this study. The well log is taken from an oil field in the Niger Delta. The study is aimed at identifying a more statistically dependable method, relative to the methods described herewith, in estimating porosity values in the Niger Delta Basin. The well was logged for Transit times, bulk density of the formation and porosity from core analysis as a function of depth. Measures of normalized root mean square error (NRMSE), relative to porosities measured from core analysis at the reservoir intervals, and coefficient of variation were employed in determining which of the estimates were more reliable. For RESERVOIR I, the NRMSE for sonic logs-derived porosites and density logs – derived porosities were 17.96% and 18.68% respectively. For RESERVOIR II, the NRMSE for sonic logs-derived porosites and density logs – derived porosities were 17.35% and 1...
Geophysics eJournal, 2020
In this study Poisson impedance pre-stack seismic inversion has been extensively studied to deter... more In this study Poisson impedance pre-stack seismic inversion has been extensively studied to determine reservoir properties in Gamma field Niger Delta, from high resolution seismic data and well logs. Three main classifications of lithology (sand, sandy-shale and shale) were discriminated based on the well log Crossplot between gamma ray and Poisson impedance. Also, well log Crossplot between density and Poisson ratio, formed three major clusters which are probably shale, brine and hydrocarbon zones. The sand lithofacies shows low values of gamma ray (< 57 API) and PI (< 5200 ft/s*g/cc) while shale lithofacies possesses high values of gamma ray (> 57 API) and PI (> 5600 ft/s*g/cc). Hydrocarbon zones show low values of PI (<4995 ft/s*g/cc) while brine and shale zones have intermediate PI (Between 5100 to 5388 ft/s*g/cc) and high values PI (> 5508 ft/s*g/cc) respectively. The value of scale factor, c was calculated to be 1.38, which was obtained from the inverse of th...
Fracture Pressure Prediction (FPP) from Well Logs
EngRN: Electronic, 2019
Qualitative study of fracture pressure prediction from composite well logs using Bower’s and Eato... more Qualitative study of fracture pressure prediction from composite well logs using Bower’s and Eaton’s methods have been carried out in order to identify hydrocarbon prospects, assessing the presence and quality of source rocks, building a structural and stratigraphic model from seismic data, provide right drilling mud weight and de-risking whether a particular play or basin should further be explored. Rock physics interpretational software ROKDOC was used to analyze the data set from the composite well logs and comparison with repeat formation tester (RFT) log data was established. The results showed that overpressure for well A and B was observed at depth below 7700ft, the formation pressure gradient ranges from 0.836psi/ft to 0.934psi/ft for well A and 0.830psi/ft to 0.928psi/ft and the fracture gradient from 0.790 psi/ft. The results of the present study would be useful in assessing seal effectiveness, mapping of hydrocarbon migration pathways, trap configuration, basin geometry, ...
Geophysics eJournal, 2020
In this study Poisson impedance pre-stack seismic inversion has been extensively studied to deter... more In this study Poisson impedance pre-stack seismic inversion has been extensively studied to determine reservoir properties in Gamma field Niger Delta, from high resolution seismic data and well logs. Three main classifications of lithology (sand, sandy-shale and shale) were discriminated based on the well log Crossplot between gamma ray and Poisson impedance. Also, well log Crossplot between density and Poisson ratio, formed three major clusters which are probably shale, brine and hydrocarbon zones. The sand lithofacies shows low values of gamma ray (< 57 API) and PI (< 5200 ft/s*g/cc) while shale lithofacies possesses high values of gamma ray (> 57 API) and PI (> 5600 ft/s*g/cc). Hydrocarbon zones show low values of PI (<4995 ft/s*g/cc) while brine and shale zones have intermediate PI (Between 5100 to 5388 ft/s*g/cc) and high values PI (> 5508 ft/s*g/cc) respectively. The value of scale factor, c was calculated to be 1.38, which was obtained from the inverse of th...
Fracture Pressure Prediction (FPP) from Well Logs
EngRN: Electronic, 2019
Qualitative study of fracture pressure prediction from composite well logs using Bower’s and Eato... more Qualitative study of fracture pressure prediction from composite well logs using Bower’s and Eaton’s methods have been carried out in order to identify hydrocarbon prospects, assessing the presence and quality of source rocks, building a structural and stratigraphic model from seismic data, provide right drilling mud weight and de-risking whether a particular play or basin should further be explored. Rock physics interpretational software ROKDOC was used to analyze the data set from the composite well logs and comparison with repeat formation tester (RFT) log data was established. The results showed that overpressure for well A and B was observed at depth below 7700ft, the formation pressure gradient ranges from 0.836psi/ft to 0.934psi/ft for well A and 0.830psi/ft to 0.928psi/ft and the fracture gradient from 0.790 psi/ft. The results of the present study would be useful in assessing seal effectiveness, mapping of hydrocarbon migration pathways, trap configuration, basin geometry, ...
A typical seal rock in a Niger Delta reservoir was studied to describe its seal integrity. The br... more A typical seal rock in a Niger Delta reservoir was studied to describe its seal integrity. The brittleness index of the seal interval was estimated by first describing some elastic properties of the seal interval, Young’s modulus and Poisson’s ratio to be specific. These measures were estimated by measuring the p- and s-wave velocity from well logs obtained from a field in the Niger Delta. Comparing these velocities with depth showed a general trend of increasing velocity with depth. A mean brittleness index of 0.20 was estimated for the seal interval of one of the wells. This is indicative of a high seal integrity, as seal rocks with brittleness index less than 0.60 are considered to have good seal integrity.
A typical seal rock in a Niger Delta reservoir was studied to describe its seal integrity. The br... more A typical seal rock in a Niger Delta reservoir was studied to describe its seal integrity. The brittleness index of the seal interval was estimated by first describing some elastic properties of the seal interval, Young’s modulus and Poisson’s ratio to be specific. These measures were estimated by measuring the p- and s-wave velocity from well logs obtained from a field in the Niger Delta. Comparing these velocities with depth showed a general trend of increasing velocity with depth. A mean brittleness index of 0.20 was estimated for the seal interval of one of the wells. This is indicative of a high seal integrity, as seal rocks with brittleness index less than 0.60 are considered to have good seal integrity.
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Papers by Onengiyeofori A . Davies