bluuebunny/crossref_metadata_2025 huggingface dataset:
Existential Suffering in Palliative Care: An Existential Positive Psychology Perspective
Authors: Wong Paul T. P. , Yu Timothy T. F.
Published: August 2021

The COVID-19 pandemic has exposed the inadequacies of the current healthcare system and needs a paradigm change, which is holistic, and community based illustrated by the healing wheel. The present paper proposes that existential positive psychology (PP 2.0) represents a promising approach to meet the rising needs in palliative care. This framework has a twofold emphasis on (a) How to transcend and transform suffering as the foundation for wellbeing, and (b) how to cultivate our spiritual and existential capabilities to achieve personal growth and flourishing. We propose that these objectives can be achieved simultaneously through dialectical palliative counselling, as illustrated by Wong’s integrative meaning therapy (Wong, 2020) and Lo’s Conceptual Model of CALM Therapy in palliative care (Lo et al., 2014). We then discuss existential suffering in general and at the last stage of life in particular; we also review recent research and interventions on existential suffering in palliative patients. Finally, we outline the objectives and the strategies of IMT in providing palliative counselling for palliative care and hospice patients.
The ‘Expo’ and the Post-‘Expo’. The Role of Public Art in Urban Regeneration Processes at the Late 20th Century
Authors: Ochoa Rita
Published: August 2021

In 1998, the Lisbon Universal Exhibition – Expo'98 – led to an urban regeneration process on Lisbon’s waterfront. Following other cities, this event was a pretext to replace a depressed area and to re-connect it with the river, through the creation of a set of new spaces for common use along the water. For them, it was promoted a public art program, which can be considered quite innovative in the Portuguese context, and that resulted in a monumentalisation of Lisbon’s eastern riverfront, later extended to other areas. Behind this framework, this article aims to debate the relations between public art and the dynamics of urban regeneration at the end of the 20th century. For that, it will analyse: 1) the Expo'98’s public art program, comparing its initial assumptions with the final results; 2) the impact of this program, through the identification of public art’s placements before (1974-1998) and after (1999-2009) the event. As a result, it is possible to find that the placement of public art reveals the spaces that were "conquered" to the port system, and a dialectic between functional/economic and leisure/symbolic values. It is concluded that public art had a significant role in the urban processes of the late 20th century, which is quite evident in a discourse that considers it as a qualifying factor of urban space and a mean of economic and social development.
Extracellular Vesicles in Skin Wound Healing
Authors: Narauskaitė Deimantė , Vydmantaitė Gabrielė , Rusteikaitė Justina , Sampath Revathi , Rudaitytė Akvilė , Stašytė Gabija , Aparicio Calvente María Isabel , Jekabsone Aistė
Published: August 2021

Each year, millions of individuals suffer from a non-healing wound, abnormal scarring, or injuries accompanied by an infection. For these cases, scientists are searching for new therapeutic interventions, from which one of the most promising is the use of extracellular vesicles (EVs). Naturally, EV-based signalling takes part in all four wound healing phases: hemostasis, inflammation, proliferation and remodelling. Such an extensive involvement of EVs suggests exploiting their action to modulate the impaired healing phase. Furthermore, next to their natural wound healing capacity, EVs can be engineered for better defined pharmaceutical purposes, such as carrying specific cargo or targeting specific destinations by labelling them with certain surface proteins. This review aims to promote scientific awareness in basic and translational research of EVs by summarizing the current knowledge about their natural role in each stage of skin repair and the most recent findings in application areas, such as wound healing, skin regeneration and treatment of dermal diseases, including the stem cell-derived, plant-derived and engineered EVs.
Tafsir Ayat-Ayat Teologis dalam al-Muharrar al-Wajiz: Studi Kritis Atas Tuduhan I’tizal terhadap Ibnu Athiyyah
Authors: Isnaini Subi Nur
Published: August 2021

Tulisan ini membahas tentang sikap Ibnu Athiyyah terhadap konsep teologi Muktazilah dalam tafsirnya al-Muharrar al-Wajiz. Meskipun Ibn Athiyyah merupakan mufassir yang bermadzhab Asy’ariyah, namun beberapa ulama seperti Ibnu Taimiyyah (w. 728 H), Ahmad bin Hajar al-Haitami (w. 973 H) dan Ibnu ‘Arafah (w. 803 H) melontarkan pernyataan bahwa dalam tafsir Ibnu Athiyyah terdapat pemahaman Muktazilah. Bahkan, al-Haitami juga menukil komentar Ibnu ‘Arafah bahwa tafsir Ibn Athiyyah lebih mengkhawatirkan bagi pelajar pemula daripada al-Kasysyaf, karena al-Zamakhsyari penulis al-Kasysyaf sudah dikenal sebagai seorang yang bermadzhab Muktazilah, berbeda dengan Ibn Athiyyah. Penelitian ini merupakan jenis penelitian kualitatif dengan pendekatan studi pustaka (library research). Dengan menggunakan metode deskriptif analisis, tulisan ini mengeksplorasi penafsiran Ibnu Athiyyah terhadap ayat-ayat yang menjadi dalil atas konsep teologi Muktazilah atau yang sering disebut dengan al-Ushul al-Khamsah. Hasil penelitian ini menunjukkan bahwa tuduhan i’tizal yang ditujukan pada Ibnu Athiyyah tidaklah benar, karena dalam penjelasan tafsirnya atas ayat-ayat teologis didapati bahwa Ibnu Athiyyah selalu menguatkan dan membenarkan pendapat Asy’ariyyah. Bahkan, dalam beberapa kesempatan Ibnu Athiyyah menyanggah pendapat-pendapat serta dalil-dalil yang digunakan Muktazilah untuk menguatkan konsep teologis mereka.
Pentingnya Nilai Persatuan Perpektif Al-Quran Surah Al-Imran Ayat 103 dalam Mengatasi Pandemi Covid-19
Authors: Mukhtar  , Hamidah Tutik
Published: August 2021

Nilai-nilai dan semangat persatuan dan larangan perpecahan telah lama ada dan diajarkan oleh Islam, seperti dalam surah Al-Imran ayat 103. Berdasarkan tafsir Ibnu Kasir, Al Misbah dan Al Qurtubi, menjelaskan bagaimana pentingnya persatuan hingga ada ancaman yang “mengerikan” apabila hal tersebut dilanggar (permusuhan/ bercerai-berai). Hal tersebut mengindikasikan pentingnya persatuan dalam kehidupan. Para ulama dan founding father kita juga telah mengingatkan tentang betapa pentingnya persatuan. Berangkat dari pentingnya nilai dan semangat persatuan, dalam konteks penanganan merebaknya covid-19, khususnya di Indonesia, nilai nilai dan semangat persatuan perlu ditanamkan ke setiap sanubari karena nilai dan semangat persatuan tersebut telah lama diajarkan dan banyak contoh keberhasilan akibat nilai persatuan. Kajian ini lebih memfokuskan kepada kajian tafsir (Ibnu Kasir, Al Misbah, dan Al Qurtubi) tentang surah Al-Imran ayat 103 dan dikaitkan dengan dalil-dalil dan teks teks yang relevan dengan nilai-nilai persatuan. Melalui metode deskriptif, dalam surah Al Imran ayat 103 menegaskan bahwa nilai nila persatuan yang ada dapat diimplementasikan dalam dalam menangani pandemic covid-19, diantaranya membingkai persatuan dalam keimanan, bersatu dalam aras ketaatan, dan bersatu dalam menangkal hoax & pengendalian diri.
Dampak Pemutusan Hubungan Kerja di Masa Pandemi Covid-19 Terhadap Ketahanan Keluarga
Authors: Rahma Nabila Luthvita , Yuniar Anisa , A'yun Fatimah Qurrotu , Kurniati Indri , Ifada Dania Saferina
Published: August 2021

The purpose of this study was to determine the impact of termination of employment during the Covid-19 pandemic on family resilience. This study uses a case approach and a law approach with primary legal sources and secondary legal sources in the form of books or legal journals related to the research title. The results of this study indicate that the termination of employment experienced by the head of the family or family member during the Covid-19 pandemic did not significantly affect family resilience, as evidenced by the divorce rate which did not increase significantly and was not caused by termination of employment. As for maintaining family resilience during the Covid-19 pandemic can be done by carrying out the rights and obligations of each family member in accordance with the study of Islamic family law, in addition to maintaining interpersonal communication between family members.
Konsep Wasiat Wajibah dalam Tafsir Surat Al-Baqarah Ayat 180
Authors: Muhajir Muhammad
Published: August 2021

This article aims to explain the basic concept of obligatory based on the letter al-Baqarah verse 180. This study uses a statutory approach, a comparative law approach and a conceptual approach. The results of this study indicate that the basic concept of determining the mandatory will is actually of benefit or goodness with istiḥsān rules that allow the transfer of the law of kulli (general) to juz'i (particular). The assumption of good (istiḥsān) is essentially goodness which is supported by the textual norms of the verses of the Qur'an. Thus, giving a mandatory will to the granddaughters as happened in the Middle East is very maslaḥat (good), because they do not get an inheritance share. Likewise, giving mandatory wills to adopted children and non-Muslim heirs is considered good and the fulfillment of a sense of justice in their lives. This provision becomes a lex specialist to make a will during his life with a certain level.

Tulisan artikel ini bertujuan untuk menjelaskan mengenai konsep dasar wajibah berdasarkan surat al-Baqarah ayat 180. Penelitian   ini menggunakan pendekatan perundang-undangan, pendekatan perbandingan hukum dan pendekatan konseptual. Hasil penelitian ini menunjukkan bahwa konsep dasar penentuan wasiat wajibah sesungguhnya bernilai kemaslahatan atau kebaikan dengan kaidah istiḥsān yang memungkinkan pemindahan hukum kulli (umum) kepada juz’i (partikular). Anggapan baik (istiḥsān) hakikatnya ialah kebaikan yang ditunjang oleh norma-norma tekstual ayat al-Qur’an. Dengan  demikian memberikan wasiat wajibah kepada para cucu pancar perempuan seperti yang terjadi di Timur Tengah sangatlah maslaḥat (baik), sebab mereka tidak memperoleh bagian waris. Demikian pula memberikan wasiat wajibah terhadap anak angkat dan ahli waris non muslim dipandang baik dan terpenuhinya rasa keadilan terhadap kehidupan mereka. Ketentuan tersebut menjadi lex spesialis untuk berwasiat semasa hidupnya dengan kadar tertentu.
Experimental Investigation of Oil-Water Two-Phase Flow in Horizontal, Inclined, and Vertical Large-Diameter Pipes: Determination of Flow Patterns, Holdup, and Pressure Drop
Authors: Ganat Tarek , Hrairi Meftah , Gholami Raoof , Abouargub Taha , Motaei Eghbal
Published: August 2021

Liquid-liquid phase flow in pipes merits further investigation as a challenging issue that has very rich physics and is faced in everyday applications. It is the main problem challenging the fluid flow mechanism in the oil and gas industry. The pressure gradient of liquid flow and flow pattern are still the topics of numerous research projects. In this paper, the emphasis is on further investigation to research the flow pattern, water holdup (HW), and pressure decrease for vertical, horizontal, and inclined flow directions of oil and water flows. Test section lines of 4.19-in. (106.426 mm) inner diameter (ID) and 5-m horizontal, 5-m inclined, and 5-m vertical test sections were serially connected. The experiments were conducted at 40°C using 2-cp viscosity oil and tap water, and oil density of 850 kg/m3, at the standard conditions. Fifty experiments were executed at 250 kPa at the multiphase flow test facility, with horizontal, upward (0.6° and 4°), downward (−0.6° and −4°) hilly terrain and vertical pipes. The oil and water superficial velocities were changed between 0.03 and 2 m/s. This evidence was obtained using video recordings; the flow patterns were observed, and the selection of each flow pattern was depicted for each condition. For horizontal and inclined flow, new flow patterns were documented (e.g., oil transfer in a line forms at the top of the pipeline, typically at high water rate, and water transfer at the lower part of the pipe at a high oil rate). The data were taken at each flow condition, resulting in new holdup and pressure drop. The results show that the flow rate and the pipe inclination angle have major impacts on the holdup and pressure drop performances. In the vertical flow, a clear peak was demonstrated by experiments after the superficial oil velocity reached a certain value. This peak is known as phase inversion point, where after this peak, the pressure starts declining as the superficial oil velocity increases. Also, slippage has been observed after varying inlet oil flow rates between the two phases. The experiments showed that with minor alteration in the inclination angle, the slippage was significantly changed. This study presented new experimental results (measured mainly at horizontal, inclined, and vertical flow conditions) of HW, flow pattern, and pressure drop. These findings are key evidence of the evolving oil-water and flowline estimate models.
Application of Acoustic Impedance and Reflectivity in Reservoir Characterization
Authors: Oifoghe Stanley , Obodozie Ikenna , Grigoletto Lucrecia
Published: August 2021

Well log analysis is one of the methods for reservoir characterization, in the oil and gas industry. Logs are used for subsurface formation evaluation. They are useful in hydrocarbon zone identification and volume calculation.

Interpretation of well log involves sequential steps, which are lithology, shale volume, porosity and saturation determination. It is unwise to analyze well log without following the logical steps, as this could introduce errors in the result. Petrophysical and Geomechanical properties are two classes of properties for reservoir characterization.

The computed volume of shale in the reservoir was 10%, the average water saturation was 30%, and the average porosity was 25pu. The bulk density decreased from 2.15g/cc to 1.95g/cc and there is a considerably lower acoustic impedance in the hydrocarbon bearing sands.

In challenging reservoirs, where traditional petrophysical methods do not give definitive results, the use of geomechanical methods will improve interpretation certainty and help to clear doubts in the interpreted results.
Estimating Fair Market Value of Petroleum Assets in Nigeria: A Risk-Based Approach
Authors: Ojukwu Kelechi , Iledare Omowumi , Ajienka Joseph , Dosunmu Adewale , Ibe Chidi
Published: August 2021

Many independent Nigerian oil & gas companies have emerged over the last decade out ofthe divestments of ageing petroleum assets by multinational oil companies. Thesetransactions are marked by pervasive cases of overvaluation and huge gap in offers that leadto unnecessarily high acquisition costs.

Petroleum analysts around the world adopt the Discounted Cashflow Analysis method forestimating present value of future oil production revenues. Unfortunately, project economicsusing conventional analysis does not de-risk the reserves components appropriately oraccount for the excess and political risk premiums. Even when analysts derive the NetPresent Value from conventional evaluation, say at discount rates of say 10% or 15%, theyface the dilemma of extracting offer price from that figure. Some post a conservative offerbased on 50% NPV, while others throw in all the NPV in a scheme to win the bid at all cost. Some also start by guesstimating value by rule of thumb and then offer the NPV that is leftbehind. The decision to offer a given percentage of the NPV is entirely subjective and variesamongst investors and as such does not depict a logical perception of market value, or therisks thereof. Furthermore, by omitting political risk, buyers are invariably ignoring the mostcrucial risk of all. The adoption of different bases of reserves tend to compound the problemby yielding NPVs that are few and far between each other. They are usually based on un-risked ‘proved plus probable’ (2P) reserves, which is highly speculative and unrealistic forvaluation.

For the first time, the concerns of high purchase price and offer gaps were debuggedleveraging the new Risk-Based Valuation approach which is based on a modified Discounted Cashflow model. A research deeply investigates the problems first by reconstructing originaltransaction to identify the root causes. Furthermore, the study concludes that buyers arepaying on average 4 times the value and that regulating reserves base is fundamental inorder to minimize offer gaps that sometimes tend to a billion dollars for large deals. Thus, the Risk-Based Discounted Cashflow Analysis technique can help prevent overpricing orunderpricing of Nigerian assets, minimize offer gaps in the market as well as account for theimpact of political risks (or its mitigation) in valuation.
Occupational Health and Safety Management and Employees’ Performance in Ardova Plc
Authors: Olagunju Olasunkanmi Olusogo , Andy Ejekwu Pascal
Published: August 2021

The vital purpose of this research work is to examine the impacts of occupational health and safety management on employee's performance. It aims to investigate the nexus between the practice of OHS, safe working environment and performance of employees. The research work adopt a descriptive approach to scrutinize the contributions of provision of adequate health and safety equipment to performance of employees at Ardova Plc. Aside collecting primary data from the staffs of Ardova Plc in Lagos State cutting across diverse socio-economic class, simple random sampling was utilised in the study using 90 questionnaires to collect the primary data. However, descriptive data was therefore analyzed using Statistical Tool to show the Cross-tabulation, correlation and Chi-Square Test. The research study concludes that practice of occupational health and safety management can boost employee performance, and further suggest some policy recommendations.
Nigeria JV Onshore OHGP Recent Experience: Beyond Flawless Execution
Authors: Adegbulugbe Kayode , Ambakederemo Akunna , Elendu Chidi
Published: August 2021

An oil producing swamp field, BX, is located in the coastal region of the western Niger Delta with an average water depth of 15 – 20 ft. The wells in the most recent development drilling campaign were designed as horizontal wells with critical well objective of meeting the target oil production rates with sand control. In order to achieve these goals, the sand control methodology deployed is the Open Hole Gravel Pack (OHGP) pumped through Concentric Annular Pack Screen (CAPS) system.

This completion methodology has similar comparisons to the AX field completions where 19 completions were successfully installed between 2016 and 2018. The lessons learnt from the AX campaign were implemented on the BX campaign and this contributed to the campaign's near-flawless completion execution evidenced by the world class operational excellence, very low Non-Productive Times (NPTs) best-in-class production performances with no sand production

However, the following opportunities were identified and implemented during the BX campaign focused on either increasing operational efficiency or preventing post-completion productivity impairment:Elimination of slickline required for tubing test operations by incorporating a "RH" catcher sub into the completion designPerforming required analysis and implementing procedural change to ensure that the change from WBM to NAF does not compromise completion performance due to the presence of reactive shales intervals encountered in the lateralDeveloping and implementing an enhanced fluid loss protocol to address the fluid loss event in one of the BX well that prevented the execution of OHGP pumping operation in the well.

The implementation of these opportunities contributed significantly to the continued consistent delivery of superior completions performance in the BX field. This paper aims to provide a background to these opportunities and highlights the steps and processes that were applied to ensure their flawless implementation.
Development of Injectivity Decline Modelling Tool: A Case Study of Onshore Niger Delta Produced Water Re-Injection Project
Authors: John Udeme , Itotoi Ibi-Ada , Isah Adeiza , Odiete Anita , Utunedi Erome , Mohamma Musa , Ikhuehi Martins
Published: August 2021

The largest component of operating costs in most matured assets utilizing 3rd party evacuation infrastructure is crude handling charges. In mature fields with significant water production, water volumes could easily account for over half of crude handling costs. Produced water re-injection for disposal has become a popular strategy for optimizing liquid handling cost as well as supporting environmental responsibility.

Injectivity for water disposal wells have been demonstrated to decline with time, the most common factor being permeability reduction arising mostly from fines migration, suspended and dissolved solids in injected water, microbial activities, oil in water and cation concentrations, etc. Thus, Injection wells typically require intermittent stimulation to restore or improve injectivity. Fracturing has been demonstrated to prolong injectivity. However, sustainability is greatly affected by ability to keep fractures open after shut-ins and limited by environmental regulations. Understanding the key mechanisms that lead to injectivity decline will help optimize produced water reinjection systems, enable proactive intervention planning, thus improve injectivity and well availability.

In this work we present the development of an injectivity modelling and simulation tool called IDS based on relatively recent injectivity models. Testing and validation of the tool using standard data and an active onshore Niger-Delta Produced Water Reinjection Project as a case study are presented.

An outstanding feature of this simulator is its ability to estimate missing parameters or those whose values are not known to high fidelity via history matching. The resulting nonlinear regression problem is solved using a trust-region reflective approach.

Decline mechanism regression parameters were similar for a well that had multiple injection periods. Transition time from deep bed to external cake is very sensitive to Total Suspended Solids (TSS) in injected water. Injectivity half-life could increase by as much as 100% for about a 100% drop in mean TSS concentration. The IDS tool was used to predict the injectivity half-life of Well A in the water disposal project.
Produced Water Re-Injection: An Integrated Subsurface Approach to Planning and Execution for Downhole Produced Water Disposal in the Niger Delta
Authors: Itotoi Ibi-Ada , Gbadamosi Taju , Ihwiwhu Christian , John Udeme , Odiete Anita , Okoro Precious , Ndubueze Maduabuchi , Utunedi Erome , Awujoola Adedeji , Adesanya Sola
Published: August 2021

Low oil price and increased environmental regulations presents a new frontier for many indigenous oil and gas companies in Nigeria. In mature fields with significant water production, produced water treatment and handling could easily account for up to a third of OPEX.

Underground produced water disposal is a tested approach that has been used worldwide with mixed results. Studies have been published on the subject; however, it was observed that there were no Niger Delta case studies. This paper presents SEPLAT's subsurface approach to in-field water disposal, drawing upon geological and petroleum engineering analysis coupled with learnings from over 6 years of produced water re-injection experience. Some of the areas that will be discussed include reservoir selection/screening methodology, water quality impact on permeability, produced water disposal well selection/completion, operating philosophy, general surveillance, and basic separation requirements.

Thirteen reservoirs located within 2 proximal fields were screened for suitability and ranked as possible candidates for water disposal based on 8 criteria. The best 2 were then high-graded and detailed studies carried out, spanning detailed geological characterization for reservoir quality and connectivity (including quantitative interpretation), to dynamic simulation, injection well location optimization and performance prediction (for clean water). The results of core flood tests were incorporated.

It is recommended that total suspended solids should not exceed 5 mg/L, with a maximum of 5 microns particle size, under matrix injection conditions while oil content should be limited to below 30-50 ppm. Tolerance for TSS can be relaxed to 10ppm – 50ppm at fracturing conditions, depending on the reservoir parameters and process systems. The knowledge of these parameters should drive the technology selection for optimum water treatment and injection.
A Practical Approach to Energy Optimization Using Pinch Analysis: A Case Study of an Oil Refinery
Authors: Ndunagu Paschal Uzoma , Alaike Emeka Emmanuel , Megueptchie Theophile
Published: August 2021

The objective of this paper is to perform an energy optimization study using pinch analysis on the Heat Exchanger Network (HEN) of a Crude Distillation Unit to maximum heat recovery, minimize energy consumption and increase refining margin. The heat exchanger network (HEN) considered comprises exchangers from the pre-heat section of the atmospheric distillation unit, which recovers heat from the product streams to incrementally heat the crude oil feed stream before entering the furnace. This paper illustrates how to perform a detailed HEN retrofitting study using an established design method known as Pinch Analysis to reduce the operating cost by increasing energy savings of the HEN of an existing complex refinery of moderate capacity. Analysis and optimization were carried out on the HEN of the CDU consist a total of 19 heat exchangers which include: process to process (P2P) heat exchangers, heaters and coolers. In the analysis, different feasible retrofit scenarios were generated using the pinch analysis approach. The retrofit designs included the addition of new heat exchangers, rearrangement of heat exchanger (re-sequencing) and re-piping of existing exchangers. Aspen Hysys V9 was used to simulate the CDU and Aspen Energy Analyser was used to perform pinch analysis on the HEN of the pre-heat train. Several retrofit scenarios were generated, the optimum retrofit solution was a trade-off between the capital cost of increasing heat exchanger surface area, payback time, energy / operating cost savings of hot and cold utilities. Results indicated that by rearrangement (Re-sequencing), the pre-heat train can reduce hot (fired heat) and cold (air and cooling water) utilities consumption to improve energy savings by 8% which includes savings on fired heat of about 4.6 MW for a payback period of 2 years on capital investment. The results generated were based on a ΔTmin of 10°C and pinch temperature of 46.3°C. Initial sensitivity analysis on the ΔTmin indicated that variation of total cost index is quite sensitive and increases with increase in ΔTmin at the temperature range of 14.5-30°C, however total cost index remains constant and minimal at a temperature range between 10°C-14.5°C for the CDU preheat train under study. In addition, the implementation of the optimum retrofit result is straightforward and feasible with minimum changes to the existing base case/design.
Innovativeness of Marginal Field Operators in Niger Delta Region
Authors: Oruwari Humphrey Otombosoba
Published: August 2021

Extant literature strongly suggest that marginal oil field operators are vital to economic growth and social development. The conjecture is that marginal field operators need to be nimble and innovative in order to survive, and this form the basic premise for this study. The objective of the study is to investigate the role of innovation as one of the success factors formarginal oil field development in Niger Delta region. The study methodology involved literature review and multiple level case study of operating marginal fields which demonstrated that innovation can bring about efficiency and cost reduction. The innovation facilitates the utilization of competitiveness and cluster system to transform the marginal field development to wealth creation. The study among other recommends that the Niger Delta region should be given urgent attention for the development of comprehensive infrastructure in order to transform the marginal field development into competitive oil and gas business.
The Impact of Outsourcing on Marginal Field Project Delivery in Nigeria
Authors: Oruwari Humphrey Otombosoba , Okolo Samuel Chinedum
Published: August 2021

The oil and gas industry in Nigeria is undergoing rapid change and explosive growth especially for marginal oil fields. Marginal oil fields operators are indigenous companies with limited profitability and some operators embrace outsourcing in their operations. Furthermore, outsourcing is process in which a company contract with another company to manage service that it does not want to provide by itself. The study examined the effect of outsourcing on marginal field operations. Using literature review and case study in India, Egypt and Malaysia by marginal field operators it is observed that outsourcing has positively contributed to delivery of marginal field project. Outsourcing is beneficial because it allows companies to reduce their fixed asset costs. Outsourcing in form of alliance between indigenous and foreign companies would enhance the credibility of the indigenous companies and stimulate capacity building in terms of knowledge and technology transfer. It is recommended that for effective outsourcing there should be a clear legal frame work.
Impact of the Finance Act 2020 on Gas Utilization Projects
Authors: Gbakon Kaase
Published: August 2021

The newly passed Finance Act 2020 (FA2020) in Nigeria is reviewed especially as it relates to the oil and gas industry. The review is partly executed by modeling the specific provisions of the Act that impact gas utilization projects. The effect of the provisions on investor returns as well as the extent to which government objectives are met is ascertained – the government objectives being to prevent tax leakage via excessive financing costs, as well as encourage gas development and utilization.

A qualitative assessment of the FA2020 is first conducted to examine its provisions applicable to the oil and gas sector. Furthermore, a spreadsheet Discounted Cash Flow (DCF) economic model of a gas central processing facility is built. A hypothetical $800Million (CapEx), 300mmscfd gas processing facility, which is 70% debt financed is modeled by incorporating the provisions of the FA2020. The metrics of the project (both investor and government) are then compared under the scenarios of with and without the FA2020.

Key results indicate that the economic returns to investor in the gas processing facility are still largely preserved at a healthy level, even as government take improves by $102Million due to the FA2020. Specifically, without the FA2020, investor returns an IRR of 21.11% while due to the FA2020, investor IRR declines to 19.79%. Sensitivity analysis serves to illustrate one of the aims of the FA2020, which is to prevent tax loss from high cost of financing. Lengthening the tenor of loans reduces the fraction of the financing costs that is tax deductible. The modeling result shows that, ceteris paribus, for one (1) year increase in loan tenor, the amount of financing cost that is tax deductible reduces by 5%. Another important outcome is that for every $1 of government receipts preserved/enhanced by the FA, the investor NPV declines by 38cents

This impact assessment of the FA2020 on gas utilization projects is conducted against the backdrop of several government pronouncements and policy positions to encourage domestic gas development. Financing plays an important role in delivering gas projects, consequently the evaluation of the impact of the FA2020 becomes imperative. This is to allow an examination of the effect of the Act on the ability to meet the strategic objective of powering the economy via gas while fulfilling Nigeria’s climate change commitments by deeper adoption of gas as a transition fuel.
Cost Element Modelling, Prediction and Optimization in a Dual-Completion Well During a Coiled Tubing Unloading Operation
Authors: Ekeregbe Merit P.
Published: August 2021

In an era where cost is a significant component of decision making, every possibility of reducing operational cost in the Oil and Gas industry is a welcome development. The volatile nature of the Oil market creates uncertainty in the industry. One way to manage this uncertainty is by the ability to predict and optimize our operations to reduce all of our cost elements. When cost is planned and predicted as accurately as possible, the operation optimizations can be managed efficiently.

Practically, all new drills require CT unloading of the completion or kill fluids to allow the natural flow of the wells. Hitherto, there is no mathematical model that combines information from one of the wells in an unloading dual completion project that can be used to aid decision-making in the other well for the same unloading project and thereby result in an effective cost-saving. Deploying the mathematical model of cost element prediction and optimization can minimize operational unloading costs. The two strings of the dual completion flow from different reservoirs. Still, the link between the two drainages post completion is the kill fluid density, and can aid in cost estimation for optimum benefit. The lesson learned or data acquired from the lifting of the slave reservoir string can be optimized to effectively and efficiently lift the master reservoir string. The decision of first unloading the slave reservoir string is critical for correct prediction and optimization of the ultimate cost.

The mathematical model was able to predict the consumable cost elements such as the gallon of nitrogen and time that may be spent on the long string from the correlative analysis of the short string. The more energy is required for unloading the short string and it is the more critical well than the long string because it is the slave string since no consideration as such is given to it when beneficiating the kill fluid to target the long string reservoir pressure with a certain safety overbalance. The rule for the mud weight or the weight of the kill fluid is the highest depth with highest reservoir pressure which is the sand on the long string.

With the data from the short string and upper sand reservoir, the lift depth and unloading operation can be optimized to save cost. The short string will incur the higher cost and as such should be lifted last and the optimization can be done with the factor of the LS.
Assessment and Optimization of Waterflooding Performance in a Hydrocarbon Reservoir
Authors: Osatemple Miracle Imwonsa , Adeniyi Adekunle Tirimisiyu , Giwa Abdulwaha
Published: August 2021

In order to properly meet up with the ever-increasing demand for petroleum products worldwide, it has become increasingly necessary to produce oil and gas fields more economically and efficiently. Waterflooding is currently the most widely used secondary recovery method to improve oil recovery after primary depletion. A crucial component required to conduct an efficient waterflooding operation is an optimal production setting, most especially with respect to the amount of water involved. This research work has been carried out to develop a model that can be used to maximize oil recovery and minimize water production with the least amount and number of waterflood variables in order to minimize the secondary recovery investment cost. The gradient-based approach to optimize the production and net present value (NPV) from a waterflood reservoir using the flow rates or bottom hole pressures of the production wells as the controlling factors with the use of smart well technology was applied. In this approach, a variant of the optimal switching time technique was used in the optimization process to equalize the arrival times of the waterfront at multiple producers, thereby increasing the cumulative oil production. The optimization procedure involved maximizing the objective function (NPV) by adjusting a set of manipulated variables (flow rates). The optimal pressure profile of the waterflood scenario that gave the maximum NPV was obtained as the solution to the waterflood problem. The proposed optimization methodology was applied to a waterflood process carried out on a reservoir field developed by a five-spot recovery design in the Niger Delta area of Nigeria, which was used as a case study. The forward run was carried out with a commercial reservoir oil simulator. The results of the waterflood optimization revealed that an increase in the net present value of up to 9.7% and an increase in cumulative production of up to 30% from the base case could be achieved.
Artificial Intelligence Model for Predicting Formation Damage in Oil and Gas Wells
Authors: Effiong Augustine James , Etim Joseph Okon , Okon Anietie Ndarake
Published: August 2021

An artificial neural network (ANN) was developed to predict skin, a formation damage parameter in oil and gas drilling, well completion and production operations. Four performance metrics: goodness of fit (R2), mean square error (MSE), root mean square error (RMSE), average absolute percentage relative error (AAPRE), was used to check the performance of the developed model. The results obtained indicate that the model had an overall MSE of 355.343, RMSE of 18.850, AAPRE of 4.090 and an R2 of 0.9978. All the predictions agreed with the measured result. The generalization capacity of the developed ANN model was assessed using 500 randomly generated datasets that were not part of the model training process. The results obtained indicate that the developed model predicted 97% of these new datasets with an MSE of 375.021, RMSE of 19.370, AAPRE of 6.090 and R2 of 0.9731, while Standing (1970) equation resulted in R2of −0.807, MSE of 9.34×1016, AAPRE of 3.10×106 and RMSE of 4.10×105. The relative importance analysis of the model input parameters showed that the flow rates (q), permeability (k), porosity (φ) and pressure drop (Δp) had a significant impact on the skin (S) values estimated from the downhole. Thus, the developed model if embedded in a downhole (sensing) tool that capture these basic or required reservoir parameters: pressure, flowrate, permeability, viscosity, and thickness, would eliminate the diagnostic approach of estimating skin factor in the petroleum industry.
EOR Consideration in Marginal Field Operations
Authors: Uche Chukwunonso , Esieboma Samuel , Uche Jennifer , Bukar Ibrahim
Published: August 2021

"Marginal field" was introduced to the oil and gas industry to identify those fields that have negative economic effects in its development. More specifically it is possible to define a marginal field as a field that is cost ineffective to develop with conventional oil and gas means of technology. Economic development of marginal fields in most cases requires the use of existing processes to minimize cost of finding evolving technologies in development of reserves. This paper generally evaluates the feasibility of using the enhanced oil recovery technique to improve reserves in a marginal field operating environment. A marginal heavy oil field in the offshore environment of the Niger Delta region which started production in 2011 is used as a case study to evaluate the feasibility of the use of enhanced oil recovery method to improve recovery.

Due to poor mobility ratio in this heavy oil field and its associated big aquifer sizes, pockets of unrecovered oil have been left behind the water fronts and water cut has risen above 80% in most of the producing wells. Recent integrated field evaluation shows that the recovery factor is poor compared to the size of oil originally in place and this triggered the need to process subsurface assessments of developing such reserves that exist in any marginal field using enhanced oil recovery technique. This paper therefore goes through the fundamental scope of an enhanced oil recovery study process to determine the applicability of this technology in a marginal oil field.
Harnessing Local Input for Job Creation-the Need for Collaboration Between the Academia and Industry; A Case Study of Carnegie African Diaspora Fellowship Program
Authors: Mbanefo Henry. C.
Published: August 2021

This paper is an attempt to design a practical model of mutually-beneficial collaboration between the academia and industry for training and graduate mentoring. This ideal collaboration is modeled for efficacy and sustainability. This paper seeks to bring to the fore, an ideal collaborative framework whereby sustainability is the key. The paper will identify several key factors and prescribe pragmatic processes for achieving an ideal mutually-beneficial collaboration for graduate mentoring, training and skill acquisition. More so, the paper will identify and prescribe the kind and level of expertise, qualification for personnel and the necessary facility needed for such trainings. Funding has been identified as one the key factors militating against the success of any collaboration. The paper will address the process of attracting funding as well as managing such funds. Areas of funding and potential collaborators will be identified. Organizational expertise is critical to the success of any ideal collaboration. The paper will match desired expertise with potential corporations as well as institutions capable of incubating such expertise and technology.
Performance Evaluation of Local Material Rice Husk Ash under Downhole Conditions with the Addition of Basic Oil Well Additives Antifoam, Fluid Loss, Dispersant and Retarder on Oil Well Cementing
Authors: Akintola Akinwale , Akintola Sarah
Published: August 2021

The effect of RHA on Compressive Strength as well as other parameters like Consistency and Rheological properties etc. on Class G cement slurry is studied. The following additives were used; Rice Husk Ash (for Compressive Strength), Guinea Corn Husk Ash (Retarder) and other liquid additives which are fluid Loss Additive, Antifoam, Dispersant, Retarder and Water in the formulation of the cement slurry. This research is a comparative analysis based on experimental study on the effectiveness of the various additives on the cement slurry using pure Class G cement slurry combined with all liquid additives as a control.

At a Bottomhole Circulating Temperature of 140°C, the Compressive Strength tests carried out on the slurry samples showed that the strength of the concrete increases as the concentration of the RHA increases with time of curing, also the compressive strength started to increase. The best Compressive Strength result was obtained with the percentages of cement replaced by 13.01% RHA. The strength showed impressive increase with time, with highest compressive strength encountered in 24 hours. The Thickening Time of the set Cement Slurry was considered using Class G cement and different percentage of RHA. The final Thickening Time decreases with increase in Rice Husk Ash. Decrease in the setting time was noticeable from 1.87 hrs (at 13.01% RHA) from 40bc to 100 bc.

At BHST of 700°C increasing the ash concentration resulted in decrease in the Plastic Viscosities (PV) and increase in the Yield Points of the slurries. The results indicate that the slurries formulated using this ash has viscosities which are within the recommended values showing it is desirable to pump such slurry. For both 124°C and Bottom Hole Pressure of 7700psi the amount of fluid loss increases as the percentage of RHA added increases but it is below 50cp which is acceptable.
Enhanced Oil Recovery Application of Nanoparticles in Niger Delta Water-Wet Reservoir Rock
Authors: Udoh Tinuola
Published: August 2021

In this paper, the enhanced oil recovery potential of the application of nanoparticles in Niger Delta water-wet reservoir rock was investigated. Core flooding experiments were conducted on the sandstone core samples at 25 °C with the applications of nanoparticles in secondary and tertiary injection modes. The oil production during flooding was used to evaluate the enhanced oil recovery potential of the nanoparticles in the reservoir rock. The results of the study showed that the application of nanoparticles in tertiary mode after the secondary formation brine flooding increased oil production by 16.19% OIIP. Also, a comparison between the oil recoveries from secondary formation brine and nanoparticles flooding showed that higher oil recovery of 81% OIIP was made with secondary nanoparticles flooding against 57% OIIP made with formation brine flooding. Finally, better oil recovery of 7.67% OIIP was achieved with secondary application of nanoparticles relative to the tertiary application of formation brine and nanoparticles flooding. The results of this study are significant for the design of the application of nanoparticles in Niger Delta reservoirs.
Zingiberales Extract ZE: A Locally Sourced Natural Compound as Gas Hydrate Inhibitor
Authors: Elechi Virtue Urunwo , Ikiensikimama Sunday Sunday , Ajienka Joseph Atubokiki , Akaranta Onyewuchi Emmanuel , Okon Okon Efiong
Published: August 2021

Gas hydrates are impediments to flow of gas and oil and its avoidance and mitigation is key to oil and gas operators. Mitigation via chemical controls is more suitable for marine environments. The effectiveness of 2wt% of an extract from the plant order, Zingiberales has been compared to that of Mono-Ethylene Glycol in a simulated offshore laboratory mini flow loop of 0.5-inch ID. The results from final pressure shows the value of ZE to be 107 psi while that of the MEG was 99 psi. The ∆P for ZE was 43 psi while that of MEG was 51 psi. The difference in ∆P was 8psi more than that of MEG. The Inhibition Capacity (%) values showed ZE to have performed better with a value of 62.28% while that of MEG was 55.26%. ZE had an Inhibition Capacity that was 7.02% more than that of MEG which is mostly imported and is termed a toxic alcohol, meaning that it is both human and environmentally hazardous. ZE therefore should be considered for development as a gas hydrate inhibitor.
Digital Transformation of Storage Tank Chart For PMS and AGO
Authors: Ayodele Emmanuel , Chukuigwe Ndubuisi , Akpogomeh Oshogwe , Bilal Ibrahim
Published: August 2021

Petroleum product needs to be stored and transported from various sources before they get to the final consumers, there by requiring storage tanks. Calibration of storage tank by dry and wet strapping process have evolved over the years with state-of-the-art facilities. The calibration charts are used to determine and know the volume of fluid in a tank given the height of the petroleum products stored in the tank. Calculating volume of a tank with the integration method has a lot of sources of error thereby affecting the result of the volume calculated and causing losses in revenue due to inaccurate calibrated tanks. With the losses in revenue due to wrong computations or computational errors, a fast, dynamic and cost-effective solutions become imperative to solve these computation problems. The tank charts having been delivered for daily usage and fiscalization process after the tank strapping process, calculation errors need to be minimized in order to report accurately petroleum products in stocks, which is a function of temperature, density and volume correction factor. This paper aims to solve the problem by semi automating the process of calculating total volume of product in stock with error free results. Approach in this paper was used and test run for a storage facility X. This paper shows how calculations from calibrated tanks can be done with a virtual method using excel spreadsheet and converted into a software for effective use and making percentage error almost zero. The results obtained from this method of computation were error free and devoid of human errors.