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Estimation of Aquifer Transmissivity using Dar Zarrouk Parameters Derived from Surface Resistivity Measurements: A Case History from Parts of Enugu Town (Nigeria)

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Journal of Water Resource and Protection 2012年第12期4卷 993-1000页

作者： Ahamefula u. utom Benard I. Odoh Anthony u. okoro Department of Geological Sciences Nnamdi Azikiwe University Awka Nigeria

Many investigation techniques are commonly employed with the aim of estimating the spatial distribution of transmissivity. unfortunately, the conventional methods for the determination of hydraulic parameters such as pumping tests, permeameter measurements and grain size analysis are invasive and relatively expensive. A geoelectric investigation involving vertical electrical sounding was carried in parts of Enugu town, Enugu state, Nigeria. The survey was aimed at extrapolating the result of pumping tests over an area. using the Dar Zarrouk parameter, a β constant of 0.32 was found to translate resistivity to transmissivity with clay content as the primary factor controlling the hydraulic conductivity. Results of the study show a strong correlation between aquifer transmissivity and longitudinal conductance (R2 = 0.82). Estimation of aquifer transmissivity values based on the results of the resistivity measurements also made it possible to demarcate area with good groundwater potential in parts of Enugu town, Nigeria.

关键词： Resistivity Transmissivity Dar Zarrouk Parameters Longitudinal Conductance Pumping Tests

尼日利亚Ariki油田地层层序、构造格架与油气运聚

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石油勘探与开发 2016年第1期43卷 77-83页

作者： AHANEKu C V okoro a u ODOH B I ANOMNEZE D O CHIMA K I EJEKE C F OKOLI I N Department of Geological Sciences Nnamdi Azikiwe University Department of Subsurface and Engineering Nubian Group Department of Physics/Geology/Geophysics Federal University

综合应用测井和三维地震数据,对尼日尔三角洲盆地西部浅海沉积带Ariki油田的构造格架和地层层序进行了解释,并开展了断裂控藏分析。该油田主力储集层Agbada组内识别出5个最大洪泛面和5个层序界面,构造格架受控于伸展构造活动所形成的主... 详细信息

综合应用测井和三维地震数据,对尼日尔三角洲盆地西部浅海沉积带Ariki油田的构造格架和地层层序进行了解释,并开展了断裂控藏分析。该油田主力储集层Agbada组内识别出5个最大洪泛面和5个层序界面,构造格架受控于伸展构造活动所形成的主断层、次级断层以及滚动背斜。研究区共发育7条断层,可划分为3个主断层和4个次级断层;在油田西翼,次级断层活动形成类似地堑和地垒的构造。通过断距分析,认为在1 800 ms以下,主断层断距加大,主断层作为油气运移通道;在1 800 ms以上,主断层断距变小,可以作为油气圈闭遮挡。研究区存在四面下倾的滚动背斜和次级断层控制的三面下倾闭合圈闭等多种远景构造圈闭,有利于提升石油区带的规模勘探潜力。

关键词：尼日尔三角洲 Ariki油田地层层序构造格架油气运聚滚动背斜断层封堵性

Consequences of unilateral cryptorchidism on semen and sperm characteristics in West African Dwarf Goats

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Asian pacific Journal of Reproduction 2018年第4期7卷 172-177页

作者： Chike F.Oguejiofor Izuchukwu S.Ochiogu Okechi L.okoro Vitalis u.Ogbu Department of Veterinary Obstetrics and Reproductive Diseases Faculty of Veterinary MedicineUniversity of NigeriaNsukka 410001Nigeria

Objective: To evaluate the influence of unilateral cryptorchidism on semen and sperm characteristics in West African Dwarf (WAD) bucks. Methods: Semen was collected using electroejaculator from five unilaterally cryptorchid (uC) and five normal (non-cryptorchid) WAD bucks and analyzed for gross, microscopic and biochemical characteristics. Results:Gross semen evaluation showed no differences between the groups in semen color, viscosity and pH, whereas the normal bucks yielded semen with significantly higher specific gravity (P=0.0436) and volume (P=0.0388) than the uC group. Following semen microscopic evaluation, the percentage of sperm vitality (live sperm) was not significantly different between both groups. However, uC bucks yielded semen with significantly lower sperm motility (P=0.0387), sperm concentration per mL (P=0.0020) and total sperm count per ejaculate (P=0.0074). The percentage total sperm abnormality was also higher (PuC goats. Abnormalities observed included sperm with cytoplasmic droplets, looped tails, coiled tails and tailless heads. Sperm morphometry showed no differences in the sperm head length and head width between the groups. Biochemical semen evaluation did not reveal any differences between the groups in the concentration of seminal plasma total protein, catalase activity and lipid peroxidation level. Conclusions: unilateral cryptorchidism significantly affected the quantity and quality of semen and spermatozoa in affected WAD bucks. Due to the hereditary attribute of the condition, it is recommended that animals with this condition should not be used in breeding to forestall increasing prevalence of cryptorchidism in goats.

关键词： Cryptorchidism Goat Semen Spermatozoa

Fibula pro-tibia vs standard locking plate fixation in an ankle fracture saw bone model

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World Journal of Orthopedics 2021年第8期12卷 548-554页

作者： Tosan okoro Kar Hao Teoh Hiro Tanaka Department of Arthroplasty Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation TrustOswestry SY107AGUnited Kingdom Department of Orthopaedic Surgery Princess Alexandra Hospital NHS TrustHarlow CM201QXUnited Kingdom Department of Orthopaedics Royal Gwent HospitalNewport NP202UBUnited Kingdom

BACKGROuND Locking plate fixation in osteoporotic ankle fractures may fail due to cut-out or metalwork *** pro-tibia fixation was a technique prior to the advent of locking plates that was used to enhance stability in ankle fractures by achieving tri or tetra-cortical *** locking plates,the strength of this fixation construct can be further *** is lack of evidence currently on the merits of tibiapro-fibula augmented locking plate fixation of unstable ankle *** To assess if there is increased strength to failure,in an ankle fracture saw bone model,with a fibula pro-tibia construct when compared with standard locking plate *** Ten osteoporotic saw bones with simulated supination external rotation injuries were *** saw bones were fixed with standard locking plates whilst the other 5 saw bones were fixed with locking plates in a fibula pro-tibia *** fibula pro-tibia construct involved fixation with 3 consecutive locking screws applied across 3 cortices proximally from the level of the *** fixations were tested in axial external rotation to failure on an electromagnetic test frame(MTS 858 Mini-Bionix test machine,MTS Corp,Eden Praire,MN,united States).Torque at 30 degrees external rotation,failure torque,and external rotation angle at failure were compared between both groups and statistically *** The fibula pro-tibia construct demonstrated a statistically higher torque at 30 degrees external rotation(4.421±0.796 N/m vs 1.451±0.467 N/m;t-test P=0.000),as well as maximum torque at failure(5.079±0.694N/m vs 2.299±0.931 N/m;t-test P=0.001)compared to the standard locking plate *** fibula pro-tibia construct also had a lower external rotation angle at failure(54.7±14.5 vs 67.7±22.9).CONCLuSION The fibula pro-tibia locking plate construct demonstrates biomechanical superiority to standard locking plates in fixation of unstable ankle fractures in this saw bone ***

关键词： unstable ankle fractures Pro-tibia fixation Improved stability Simulated biomechanical analysis Osteoporotic fractures Ankle injuries

Predicting the effects of selected reservoir petrophysical properties on bottomhole pressure via three computational intelligence techniques

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Petroleum Research 2023年第1期8卷 118-129页

作者： Emmanuel E.okoro Samuel E.Sanni Tamunotonjo Obomanu Paul Igbinedion Department of Petroleum Engineering University of Port HarcourtRivers StateNigeria Department of Chemical Engineering Covenant UniversityOtaNigeria Department of Petroleum Engineering Federal Polytechnic of Oil and GasBonny IslandNigeria Department of Petroleum Engineering Covenant UniversityOtaNigeria

This study investigates the effects of selected petrophysical properties on predicting flowing well bottomhole *** efficiently situate the essence of this investigation,genetic,imperialist competitive and whale optimization algorithms were used in predicting the bottomhole pressure of a reservoir using production data and some selected petrophysical properties as independent input variables.A total of 15,633 data sets were collected from Volvo field in Norway,and after screening the data,a total of 9161 data sets were used to develop apt computational intelligence *** data were randomly divided into three different groups:training,validation,and testing *** case scenarios were considered in this *** first scenario involved the prediction of flowing bottomhole pressure using only eleven independent variables,while the second scenario bothered on the prediction of the same flowing bottomhole pressure using the same independent variables and two selected petrophysical properties(porosity and permeability).Each of the two scenarios involved as implied in the first scenario,the use of three(3)heuristic search optimizers to determine optimal model *** optimizers were allowed to choose the optimal number of layers(between 1 and 10),the optimal number of nodal points(between 10 and 100)for each layer and the optimal learning rate required per task/*** results,showed that the models were able to learn the problems well with the learning rate fixed from 0.001 to 0.0001,although this became successively slower as the leaning rate *** the chosen model configuration,the results suggest that a moderate learning rate of 0.0001 results in good model performance on the trained and tested data *** the three heuristic search optimizers based on minimum MSE,RMSE,MAE and highest coefficient of determination(R^(2))for the actual and predicted values,shows that the imperialist competitive algorithm optimizer predicted

关键词： Computational intelligence Bottomhole pressure Petrophysical properties Heuristic search optimizer Volvo field data

Application of artificial intelligence in predicting the dynamics of bottom hole pressure for under-balanced drilling:Extra tree compared with feed forward neural network model

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Petroleum 2022年第2期8卷 227-236页

作者： Emmanuel E.okoro Tamunotonjo Obomanu Samuel E.Sanni David I.Olatunji Paul Igbinedion Petroleum Engineering Department Covenant UniversityOtaNigeria Petroleum Engineering Department Federal Polytechnic of Oil and GasBonnyNigeria Chemical Engineering Department Covenant UniversityOtaNigeria

This study used six fields data alongside correlation heat map to evaluate the field parameters that affect the accuracy of bottom hole pressure(BHP)*** six oil field data were acquired using measurement while drilling device to collect surface measurements of the downhole pressure data while *** the two case studies,measured field data of the wellbore filled with gasified mud system was utilized,and the wellbores were drilled using rotary jointed drill *** Randomized Tree and feed forward neural network algorithms were used to develop models that can predict with high accuracy,BHP from measured field *** modeling purpose,an extensive data from six fields was used,and the proposed model was further validated with two data from two new *** gathered data encompasses a variety of well data,general information/data,depths,hole size,and *** developed model was compared with data obtained from two new fields based on its capability,stability and *** result and model’s performance from the error analysis revealed that the two proposed Extra Tree and Feed Forward models replicate the bottom hole pressure data with R2 greater than *** high values of R^(2) for the two models suggest the relative reliability of the modelling *** magnitudes of mean squared error and mean absolute percentage error for the predicted BHPs from both models range from 0.33 to 0.34 and 2.02%-2.14%,for the Extra tree model and 0.40-0.41 and 3.90%e3.99%for Feed Forward model respectively;the least errors were recorded for the Extra Tree ***,the mean absolute error of the Extra Tree model for both fields(9.13-10.39 psi)are lower than that of the Feed Forward model(10.98-11 psi),thus showing the higher precision of the Extra Tree model relative to the Feed Forward *** has shown that underbalanced operation does not guarantee the improvement of horizontal well’s extension ability,because it mainly depends on t

关键词： Artificial intelligence Bottom hole pressure Extra tree Predictive model Oil and gas Feed forward algorithms

Artificial intelligence model for predicting geomechanical characteristics using easy-to-acquire offset logs without deploying logging tools

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Petroleum 2022年第2期8卷 192-203页

作者： Temitope F.Ogunkunle Emmanuel E.okoro Oluwatosin J.Rotimi Paul Igbinedion David I.Olatunji Department of Petroleum Engineering Covenant UniversityOtaNigeria

This study focuses on predicting acoustic and mechanical rock properties using random forest and feed forward neural network models to evaluate the likelihood of developing efficient ways of handling absence of rock properties at offset *** Random Forest algorithm was used for direct prediction of the sonic data without considering the depth range of the facies;while Feed forward Neural network was used to predict the sonic data with emphasis on the lithofacies *** accuracy of these approaches was used in choosing the best and the most robust model for predicting sonic data when estimating formation strength and mechnical *** log was predicted after training a combination of caliper log,gamma log,depth,density log and resistivity log from offset wells.5 hidden layers that accounts for the data structural complexities was included in the model architecture.A multilayer perceptron network was adopted for the Random forest algorithm to handle linear combinations of input data *** error computations were used to evaluate the performance of the ***,mechanical properties and sanding potential was evaluated using standard relations and appropriate depositional *** forest algorithm gave the best prediction accuracy of more than 96%,but the Feed forward network has the lower mean absolute error and mean squared error of 2.75 and 5.93 ***,the predicted compressive and shear wave velocity show increase of values with depth,a behavior that is capable of identifying payzone *** was validated by the distinction seen within the 200 feet gas sand formation in the deeper portion of the studied well(9600e9800 feet).Potential failure portions of the wells,a common feature in the field,were inferred from the sanding potential computed using the predicted mechanical properties value.

关键词： Shear wave velocity Mechanical properties Random forest Feed forward neural network Sanding potential

Clinical outcome of open ankle fractures in patients above 70 years of age

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World Journal of Orthopedics 2023年第7期14卷 554-561页

作者： Wajiha Zahra Mina Seifo Paul Cool David Ford Tosan okoro Department of Trauma and Orthopedics Royal Shrewsbury HospitalShrewsbury SY38XQUnited Kingdom Department of Trauma and Orthopedics Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation TrustOswestry SY107AGUnited Kingdom Department of Trauma and Orthopedics Keele UniversityStafford ST55BGUnited Kingdom

BACKGROuND Open fractures of the ankle are complex injuries requiring multidisciplinary input and are associated with significant morbidity and ***,data on the clinical outcomes of open ankle fracture management in patients older than 70 is *** To evaluate the clinical outcomes following open ankle fracture management in patients older than *** secondary aim is to look at predictors of poor *** Following local research and audit department registration,22 years of prospectively collated data from an electronic database in a district general hospital were *** patients older than 70 years of age with an open ankle fracture requiring surgical intervention were *** information,the nature,and the number of surgical interventions were ***,including surgical site infection(SSI),venous thromboembolic events(VTEs)during hospital stay,and mortality rate,were *** A total of 37 patients were identified(median age:84 years,range:70-98);n=30 females median age:84 years,range:70-97);n=7 males median age:74 years,range:71-98))who underwent surgical intervention after an open ankle *** patients developed SSIs(43%).Superficial SSIs(n=8)were managed without surgical intervention and treated with antibiotics and regular dressing *** SSIs(n=8;20%)required a median of 3(range:2-9)surgical interventions,with four patients requiring multiple washouts and one patient having metalwork *** incidence was 5%during the hospital *** patients died within 30 d,and mortality at one year was 19%.The 10-year mortality rate was 57%.The presence of a history of stroke,cancer,or prolonged inpatient stay was found to be predictive of lower survivorship in this population(log-rank test:cancer P=0.008,stroke P=0.001,length of stay>33 d P=0.015).The presence of a cardiac history was predictive of wound complications(logistic regression,P=0.045).Age,number of operations,and di

关键词： Fragility fracture Open fracture Clinical outcome Mortality Infection Survival

Evaluation of influential parameters for supersonic dehydration of natural gas: Machine learning approach

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Petroleum Research 2022年第3期7卷 372-383页

作者： Emmanuel E.okoro uyiosa Igbinedion Victor Aimikhe Samuel E.Sanni Okorie E.Agwu Department of Petroleum and Gas Engineering University of Port HarcourtNigeria Department of Petroleum Engineering.Covenant university OtaNigeria Department of Chemical Engineering Covenant UniversityOtaNigeria Department of Petroleum Enginering University of UyoNigeria

The supersonic dehydration of natural gas is gaining more attention due to its numerous advantages over the conventional natural gas dehydration ***,supersonic separators have seen minimal field applications despite the multiple benefits over other gas dehydration *** has been mostly attributed to the uncertainty in ascertaining the design and operating parameters that should be monitored to ensure optimum dehydration of the supersonic separation *** this study,the decision tree machine learning model is employed in investigating the effects of design and operating parameters(inlet and outlet pressures,nozzle length,throat diameter,and pressure loss ratio)on the supersonic separator performance during dehydration of natural *** model results show that the significant parameters influencing the shock wave location are the pressure loss ratio and nozzle *** former was found to have the most significant effect on the dew point *** dehydration efficiency is mainly dependent on the pressure loss ratio,nozzle throat diameter,and the nozzle *** the machine learning model-accuracy with a 1-D iterative model,the machine learning model outperformed the 1-D iterative model with a lower mean average percentage error(MAPE)of 5.98 relative to 15.44 as obtained for the 1-D model.

关键词： Supersonic separator Machine learning model Natural gas dehydration Separation efficiency