bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heavy Oil Development and Reserve Addition Potentials: The Abura-6ST Case
Authors: Ijomanta Henry , Ifeduba Ebuka , Ayeni Olayinka , Akenobo Charles , Okoh Oluchukwu , Igbokwe Obianuju , Adebayo Odude 
Published: July 2023

Abstract
This paper evaluates the effect of the increment in recovery factor of the Abura Heavy Oil reservoirs on the heavy oil portfolio of NNPC E&P Limited and, ultimately, the reserve valuation of Nigeria as a country, considering that the Niger Delta basin has a significant amount of heavy oil reservoirs.
The Abura field has three (3) heavy oil reservoirs (1AB6, 2AB6 and 3AB6) with viscosity ranging between 10-17cp. These reservoirs were booked as contingent resources owing to sub-optimal production using conventional techniques and sub-commerciality. An FDP study in 2018 revealed that the heavy oil reservoirs could not sustain production and hence, are uneconomically viable to develop. The initial reservoir simulation results showed flow assurance issues mainly due to the high oil viscosity and consequently poor production rate, high water cut, and high-pressure drawdown due to unfavorable mobility ratios and flow assurance challenges caused by the high oil viscosity. Improved Oil Recovery (IOR) techniques were designed to combat the highlighted issues. The combination of IOR techniques employed includes deploying a Single Well Multiple completion which allowed the completion and commingling of 2 reservoirs (1AB6 and 2AB6) in the same tubing for increased oil production, deploying an Electrical Submersible Pump (ESP) to solve vertical lift challenges, installing Autonomous Inflow Control Devices (AICDs) to allow the preferential flow of oil, hydrocarbon fingerprinting for reservoir management and production allocation, and Micro Emulsion Based (MEB) stimulation post-completion, to reduce skin due to formation damage.
The results led to a significant increase in the forecasted production and, therefore, an increase in the reservoirs’ Expected Ultimate Recovery (EUR). This led to an eventual improvement of recovery factors for both reservoirs, positive migration of the contingent resources to reserves, increased revenue for the company, and a positive outlook for the numerous heavy oil resources in the company portfolio.
Well Management: Top Tier Well Approach
Authors: Bakenne Sulaiman , Oboh Stephen , Lucky Ishomo , Ugwa Iheanyi 
Published: July 2023

Abstract
Effective well management and reliability are fundamental to ensuring high well production uptime with the attendant benefit of minimizing unscheduled volume loss. Well equipment reliability is impacted by the scope and frequency of preventive maintenance (PM) in place. The optimum PM frequency is one that maximizes incremental value with reduced equipment failures. While defining the PM program, due consideration must be given to the well risk (business and safety) which impacts consequence level of failures. In matured assets with high well counts, PM programs should be structured to maximize uptime of wells with significant volume contribution, critical gas producers to support gas lift systems and injectors while also minimizing process safety risk on all wells. These wells are referred to as top tier wells.
This paper defines criteria for selecting top tier wells. It also focuses on using a Prevent-Detect- Respond-Recover (PDRR) approach in defining a well equipment PM program that meets industry and local regulatory requirements to drive improved reliability of the top tier wells.
Prevent-Detect initiatives leverage Root-Cause-Failure-Analysis (RCFA) data to minimize the likelihood of equipment failure, and by extension, provide a focused surveillance system to ensure failures are detected before equipment are taken out of service. Whereas Respond-Recover initiatives provide a defined response plan to well equipment reliability issues through low complexity intervention actions and subsequent detailed repairs to correct detected failures with minimal downtime impact.
The benefit of a top tier approach to PM is to drive incremental business benefit for the asset through optimization of existing resources.
Application of Blockchain Technology in the African Energy Industry: Use Cases, Limitations and Solutions
Authors: Chime C. E. 
Published: July 2023

Abstract
This paper explores the potential application of blockchain technology in the African energy industry, in the process, highlighting various use cases, identifying limitations, and proffering solutions to these limitations. The African energy industry is plagued by a plethora of problems such as a lack of access to reliable energy, the absence of transparency and trust, and limited access to financing amongst others. Blockchain technology can be employed to address these challenges by providing secure and transparent platforms for energy transactions, enabling peer-to-peer energy trading, and facilitating access to financing for both renewable and fossil energy projects. On the other hand, the implementation of blockchain technology in the energy industry faces several limitations which include a lack of regulatory clarity or a defined framework, inadequate infrastructure, and a lack of technical know-how. To address these limiting factors, this paper proffers several solutions such as the development of a clearly defined regulatory framework to enable the implementation of blockchain technology, the creation of industry standards to ensure interoperability and uniformity, and the promotion of education and training programs to build technical expertise. This paper also highlights existing case studies of blockchain-based energy projects in Africa to demonstrate the potential of blockchain technology in the energy industry. The paper concludes that while blockchain technology has the potential to revolutionize the African energy industry, early adoption is key and the importance of addressing existing limitations cannot be overemphasized.
Implementation of One-Trip Acid-Jetting Solution in AX field for an Operator in Nigeria
Authors: Ngerebara Justus , Alawode Olusiji , Hamzat Ismail , Gerber Jesse , Olaobaju Oluwaseyi , Onuoha Jombo , Espinoza Omar , Andrew Colin 
Published: July 2023

Abstract
The paper describes the integration of Service Provider's one-trip washpipe-conveyed Jetting-tool assembly with an 8.5″ open-hole horizontal stand-alone-screen sand-face completion for optimal delivery of acid treatment to the sand-face of injector well typically performed post completion following poor injectivity.
AX field injectivity performance has been on the declined mostly attributed to poor sand development, shorter horizontal interval (Low NtG), fines migration, hammer effect, and ineffective removal of filter cakes. To manage this, Operator employed two main approaches to tackle the problems which include the use of check valve screens and Jetting tool for acid treatment at the sand face to effectively dissolve and remove filter cake following a learning from Gulf of Mexico in 2021 (OTC 31713). The integrated team, comprising of Operator and Service provider carried out extensive design upgrade and modifications of the Jetting tool technology. Additional scope included integration with a separate third-party service tool and adapting a barrier valve's shifter tool in the Jetting tool.
The Jetting-tool technology has been successfully implemented in the acid treatment of two injector wells in the AX field with reported early positive signs of improved injectivity thereby removing the high cost of post-completion stimulation to enhance injectivity.
This new approach allows the operator to save significant post-completion intervention costs by adding the stimulation capability to the completion phase of the well, obtaining a better well-injectivity performance at a reduced cost which would have been otherwise done with coil tubing.
The Future Perspective: Geothermal Energy in Nigeria – An Option to be Explored
Authors: Kelechi F. M. , Owoka O. I. 
Published: July 2023

Abstract
As the transition towards a green energy future intensifies, cleaner energy sources are expected to drive the decline in the demand for fossil fuels. This creates room for renewable energy sources such as geothermal. Geothermal energy is generated from the earth's crust which is transported through cracks and fractures in the host rocks and its natural fluids at temperatures above the ambient level. The rate of heat flow in the crust is estimated to be 59Mw/m2 [1.9*10-2 Btu/h/ft2]. In mature continental cratons, the geothermal gradient can be as low as 10 °C per kilometer. However, in active volcanic areas, it can exceed 100 °C per kilometer. A typical geothermal gradient of 25 °C km− 1 gives a conductive heat flux of 60 mWm− 2 for electricity generation. Considering the Nigerian basement complex, the estimated geothermal gradient of Borno and Sokoto States, both located in the Northern region are 1.1 to 5.9°C/100m with a heat flow of 8.9 to 117.8mW/m-2 and 0.9 to 7.6°C/100m with a geothermal heat flow of 52.11 to 130.28mWm-2 respectively. In addition, in eastern Nigeria, Anambra State, the estimated geothermal gradient is 2.5 to 4.9°C/100m with a heat flow of 64.4 to 97.3 mWm-2. Geothermal energy has the potential to improve Nigeria's current poor energy dynamic. Enhanced Geothermal System would exploit heat energy that is trapped in the subsurface host rock by creating an open system of connected fractures along which water can flow down the injection wells and get heated through contact with the rocks. This is then recovered to the surface in production wells to form a closed loop. The idea is an extrapolation that emulates a hydrothermal circulation system – which produces electricity that can be applied commercially.
Geomechanical Risks Screening of Producing Fields – Key Contribution to Safety Standards
Authors: Arogun Olubunmi , Schutjens Peter , Anijekwu Chinedu 
Published: July 2023

Abstract
Production of oil and gas, as well as injection of water, gas, or steam, will generally cause a change in pore pressure, total stresses and temperature in the reservoir and its surrounding formations. The resulting stress changes may cause compaction or lead to shear failure or tensile fracturing, that in turn can lead to fluid containment issues and compromise the integrity of the wellbore and surface facilities. In line with the company's Goal Zero vision, 48 active fields in the Niger Delta, some of which have been producing since the 70s, were subjected to fit-for-purpose screening to ensure geomechanical risks associated with our operations were identified and adequately handled. Some of the fields are highly faulted and compartmentalized. Oil accumulations are fault controlled and several of the fields have gas caps.
The screening identified risks such as sand control, compaction and subsidence, top seal integrity loss and wellbore instability in the fields. The risks were assessed using the Risk Assessment Matrix to check potential impact on safety and production and the probability of occurrence which ranged from low to medium. In compliance with process safety requirements, the risk of reservoir compaction was evaluated using 1D analytical models. The screening resulted in proposals of integrated solutions to address and mitigate the risks. The recommendations included, 1) acquisition of core measurements to reduce uncertainty of uniaxial strain compressibility required to estimate reservoir compaction, and 2) mechanism-based evaluation of seal integrity to analyze the potential of out-of-zone-injection and cross flow between reservoirs. Some recommendations have been implemented to reduce the risks to as low as reasonably possible (ALARP).
This paper presents our method of geomechanical risk screening and gives examples of its positive impact on the company's safety standards via implementation of integrated solutions to prevent or mitigate the geomechanical risks.
Evaluation of Groundnut Shell and Yam Peel as a Loss Circulation Control Material in Drilling
Authors: Ishaku Y. , Okafor I. , Jakada K. , Nzerem P. , Salihu A. 
Published: July 2023

Abstract
As a result of enormous uncertainties and high cost of materials employed in the design and formulation of drilling fluids used drilling operations in the oil and gas industry, it is important to select the most appropriate drilling materials to increase drilling efficiency, while reducing the total cost of drilling through import substitution, especially with locally available materials. In this paper, an experiment was conducted to test and investigate the suitability of Yam Peel and Groundnut Shell as loss circulation materials. The selected lost circulation material was washed, purified, dried, and crushed, thereafter the materials were characterized using the FTIR and SEM. Different mud samples were prepared using the locally sourced materials and Carboxymethyl Cellulose (CMC), tested for its rheological properties, and thereafter compared to ascertain the suitability of the mud prepared with the locally sourced lost circulation material drilling, in line with established API standard. Results obtained shows viable comparison between the locally sourced loss circulation material and its imported lost circulation material.
Hydrodynamic Cavitation as Oil Pretreatment Prior to Distillation
Authors: Ajinomoh C. S. , Momoh O. R. , Maku J. J. 
Published: July 2023

Abstract
Hydrodynamic cavitation has been employed in literature to distort the structure of crude oil as a way of its intensification prior to refining, with majority paying attention to adding additives in order to improve the yield. No attention has been paid to varying the storage time of the crude after cavitation. Hence, it was thought necessary to vary the storage time after cavitation in order to increase the yield of crude oil. 350 g of the feedstock was characterized and then continuously circulated through an orifice/cavitation device for 30s, then it was stored in an airtight plastic container. The storage time was varied from 2 hours to 240 hours for different runs. True boiling Point distillation for 295g of the cavitated crude was carried out after. The results showed that there was a strong correlation between the changes in the density of the stored cavitated crude and the yield of the crude. The yield of lighter distillate/fractions increases with reduction in density of stored cavitated crude and the yield of heavier distillate increases with increase in density of cavitated crude. The increase in the yield of light fractions was attributed to cold cracking of heavier molecules in the crude and the increase in yield of heavier fractions was attributed to the recombination reactions of the radical molecules in the crude. The increase in the overall yield when compared with untreated crude can be achieved by striking a balance between cold cracking and recombination reactions which occurred at 122 hours of storage after cavitation
Evaluating the Potential of Renewable Energy to Address Energy Accessibility, Affordability, and Sustainability Challenges in Africa
Authors: Ezeh M. C. , Fidel-Anekwe T. H. , Ikpabi P. B. 
Published: July 2023

Abstract
Energy accessibility, affordability, and sustainability are crucial factors for developing any country, particularly in Africa. The numerous challenges most African population face in providing reliable and affordable energy to their communities hinder economic and social development.
This study evaluates the potential of renewable energy to address energy accessibility, affordability, and sustainability challenges in African countries. To do this, the study involves a review of successful renewable energy projects in Africa and an analysis of energy consumption and production data. Several key factors are considered in this analysis. Firstly, this study examines the feasibility of different renewable energy technologies in African contexts. This includes an assessment of the potential for solar and wind power to provide reliable energy, as well as an examination of other renewable energy options. Secondly, the study considers the economic and financial implications of renewable energy adoption. This includes analyzing the costs and benefits of different renewable energy technologies, including examining the financing and investment requirements for renewable energy projects.
Finally, this study assesses renewable energy's social and environmental impacts in Africa. This includes an evaluation of the potential for renewable energy to improve energy access in disadvantaged communities and examining the environmental benefits of renewable energy. By examining successful renewable energy projects and analyzing energy consumption and production data, this study provides strategic recommendations on how African countries can adopt renewable energy technologies to enhance their energy systems and transition to cleaner energy sources.
Prediction of Thermal Conductivity of Rocks in Geothermal Field Using Machine Learning Methods: a Comparative Approach
Authors: Ekeopara P. U. , Nwosu C. J. , Kelechi F. M. , Nwadiaro C. P. , ThankGod K. K. 
Published: July 2023

Abstract
Thermal conductivity of rocks defined as the ability of rocks to transmit heat, can indicate the potential for geothermal resource in a given location. While direct laboratory core sample analysis and indirect analysis leveraging empirical correlations from electric logs are used to determine thermal conductivity of rocks, they are usually expensive, time consuming and difficult to implement. Hence, in this study, several machine learning methods specifically Gradient Boosting Regressor, Random Forest, K-nearest neighbour, ensemble method (voting regressor), and Artificial Neural Networks were developed for the real-time prediction of thermal conductivity of rocks in geothermal wells. Data being obtained from Utah Forge field project included drilling data, thermal conductivity data and other necessary information from the field. With real-time sensor drilling data such as Rate of penetration (ROP), surface RPM, Flow in, Weight on bit (WOB), and Pump pressure, as input parameters and matrix thermal conductivity (MTC) as output, the models were developed. The results obtained from this study, showed excellent performances for majority of the models. However, it was observed that the ensemble voting regressor, which combined the top three models was able to predict thermal conductivity with above 89% and 80% R2 scores on the train and validation datasets respectively. Thus, this research work describes the feasibility of leveraging several machine learning methods in estimating thermal conductivity of rocks which is cost effective, and practically achievable.
Modified Straight-Line Depreciation Model for Upstream Petroleum Investment
Authors: Ogolo Oghenerume , Iyalla Ere , Tahir Salahudden M. , Ileogbunam Emeka , Egede Frank , Obe Ayodele 
Published: July 2023

Abstract
Depreciation is a method used to recover the cost of an asset or facility used to develop and produce petroleum from any oil and gas field. The challenge with the straight-line depreciation method used to depreciate an asset was, it does not take into consideration the time value of money. Over time, the value of money changes. The amount recovered after the depreciation period is usually less than the future value of the asset. This is because the value of money today is not the same as the value of money tomorrow. Hence, there was the need to incorporate the time value of money into the straight-line depreciation model. This research considered the incorporation of the time value of money into the depreciation equation. The conventional straight-line depreciation equation was modified by incorporating the time value concept of money into the equation. A petroleum economic model was developed using a spreadsheet approach. The model was used to evaluate the impact of the modified straight-line depreciation model on the profitability of petroleum investments. Two petroleum investment scenarios were considered. Scenario 1 had the conventional depreciation model. Scenario 2 had the modified depreciation model for comparative analysis. The effect of the conventional and modified depreciation model on the profitability of the investment was evaluated. The NCF of the contractor for Scenarios 1 and 2 when the oil price was $50/bbl was $214 MM and $317 MM respectively. While the NCF of the host government for Scenarios 1 and 2 when the oil price was $50/bbl were $627 MM and $524 MM respectively. It was observed that the incorporation of the time value of money into the depreciation equation increased the NCF of the contractor. This allowed the contractor to mitigate the effect of risk associated with the value of the asset over time due to inflation. The modified depreciation model made the petroleum fiscal arrangement more attractive.
Oil & Gas Production Capacity Digitalization – A Strategic Approach to Production Deferment Management
Authors: Adebajo A. K. , Duruzor E. D. , Oyakhire B. O. , Onasanya B. A. , Nwangwu C. V. , Michael E. O. , Akpedeye D. O. , Afere O. O. , Ayalogu D. I. 
Published: July 2023

Abstract
Deferred production is a common occurrence in the E&P industry particularly for mature assets, usually accounting for significant volumes to an assets total production. As a result, E&P companies are continually pursuing innovative ideas and leveraging the latest technologies to support earlyidentification of underperforming wells to minimize production loss and maximize asset recovery.
This paper focuses on Oando Energy Resources (OER) in-house development and operationalization of a Production Capacity Digitalization solution. A continuous business process improvement initiative geared towards enhancing the management of the company's portfolio of shut-in wells and reporteddeferred volumes. The digital solution is designed to guide senior management towards strategic planning and achieving cost-effective production restoration by integrating time, budgetary and economic factors in a single platform for shut-in volumes classification.
The digital platform integrates multi-disciplinary asset data, deferment management processes withorganizational structure and leverages petroleum engineering workflows (validation, diagnosis & analysis) for systemic understanding and collaboration of stakeholders, to make informed decisions on volumes restoration efforts, ensure the technical team is chasing the "right" volumes forrestoration and focus on high priority assets with critical production capacity.
This paper describes the production capacity workflow, implementation, development strategy, valueproposition and benefits of the solution to OER on her quest for improved business performance management and operations excellence in order to maximize value for all stakeholders.