bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Water Injection Performance in Heterogeneous Reservoirs Using Analytical Hierarchical Processing and Fuzzy Logic
Authors: Oluwajuwon Ifalade , Olugbenga Falode 
Published: October 2018

Abstract
Heterogeneous reservoirs are reservoirs containing many thin bed layers which may or may not be connected and are separated by low permeability barriers. After primary recovery, they are made to undergo secondary recovery, most commonly water injection. There is great difficulty in evaluating the efficiency of this process analytically due to the degree of heterogeneity of the reservoirs. Getting data for analytical solutions also has high economic implication. Fuzzy logic has found extensive use in engineering problems that are too complex to be solved using crisp logic. Zhao et al developed a model using Analytical Hierarchy Process (AHP) and Comprehensive Evaluation method of Fuzzy Logic by generating comprehensive evaluation coefficients (E2 values) for each well group. It however under-predicts or overestimates efficiency when there are factors which have outlying values (which may be due to gas caps, permeability jails or thief zones).
This paper seeks to develop a model using AHP and Controlled Fuzzy Logic to address the existing challenges in the above model. AHP is used to attach weights to the factors influencing performance namely; incremental oil production, water absorption ratio, and producing degree of waterflood. The E2 values are then generated for wells by introducing a new membership function.
The two models were applied to data from Ba fault block and the results compared. Both models were applied to data with outlying value and the results were compared. Results were similar for the former case but for the later, Zhao et al’s model predicted much lower efficiencies for wells it had already considered more efficient. The controlled Fuzzy model retained close E2 for both cases.
This model can help in prioritize water allocation to well groups in limited water supply, decide on introduction of EOR like acidizing or fracturing, cut cost on inefficient wells using the cumulative E2 distribution table.
Economic Evaluation of the Dual Petroleum Tax System Proposed in the 2017 Nigeria Fiscal Reform Framework
Authors: Amiesa Fubara Susan , Omowunmi Iledare , Joseph Akinlawon Adeyemi 
Published: October 2018

Abstract
Petroleum taxation is an instrument of government use to create a crucial rent sharing balance between oil and gas companies and host government. The petroleum profit tax imposed by the Nigerian government on upstream petroleum operators is an example. However, the complexity of the petroleum taxation due to the continued evolution in the international crude oil market dynamics, due to geogolical, technical, economic and political factors, prompts the quest for a tax system that will accrue a fair revenue to the government with acceptable returns to multinational oil companies. The propostion of a dual tax system in the 2012 PIB and 2017 Nigeria Petroleum Fiscal framework is designed to equitably satisfy stakeholders expectations. Concerns on how fair the dual tax system will be to the investor and government motivated the essence of this paper. The paper attempts to evaluate the proposed tax system in PIB 2008, PIB 2012 and Petroluem Fiscal Policy 2017. The paper applied a deterministic R/T system cash flow model for a continental shelf to rank the perfomances of the fiscal terms proposed in PIB 2008, PIB 2012 and in the 2017 NPFP document. From our analysis, we discovered that the economic metrics for the project depicted a better profitability for the operators under a dual tax system than a single tax system within the contex of our cost assumptions and profile. However, the same feat was not recorded for the government take as the dual tax system led to a slight decrease in the government take statistics rather than an increase. We considered this slight decline as a positive trade off that debunks the assumption amongs shareholders that the 2017 NPFPF dual tax system accrues more benefits to the government. Hence, we recommend the implementation of dual tax system as a favourable option for the investors and government.
Embedding and Operationalizing Sustainable Development Goals in the Nigerian Oil and Gas Industry
Authors: Ite Dr Uwem 
Published: October 2018

Abstract
The concept of sustainable development emerged from global public pressure in the 1980s and ultimately forced itself onto the agenda of governments and international institutions. It is now embraced as the global standard for measuring development objectives and performance in both developed and developing countries. The emergence of the Millennium Development Goals (MDGs) in 2000, and its subsequent replacement by the Sustainable Development Goals (SDGs) in 2015, clearly shows that the concept has indeed made significant progress by moving from global rhetoric and debates to local practice and action. The SDGs aim to address economic, social and environmental challenges. Member states of the United Nations (including Nigeria) are expected to use the SDGs to frame their development agendas, while clearly recognizing that the private sector has an important role to play in this regard. There is no doubt that the oil and gas industry is central to sustainable development in many national economies. Oil and gas are key pillars of the global energy system. As such, they are critical drivers of economic and social development. Although the industry contributes to sustainable development in several ways, its operations and products potentially have negative impacts on a range of areas covered by the SDGs, including communities, ecosystems and economies. Within the context of sustainable development in Nigeria, the overarching aim for the Nigerian oil and gas industry is to do business responsibly by contributing to society; minimizing risks and doing no harm. This paper demonstrates that with careful planning and implementation, the Nigerian oil and gas industry can contribute across all SDGs by enhancing its positive contributions as well as avoiding or mitigating the negative impacts associated with its operations. Three fundamental steps are necessary in this regard, namely: identification of relevant SDGs; stakeholder engagement and collaboration. The Nigerian oil and gas industry can embed and operationalize the SDGs in their core business practices by incorporating carefully chosen and relevant SDGs into their corporate systems, policies and processes.
Analysis of Vibrations in Drilling Systems
Authors: Osogba O. J. , Otamere B. , Abdullahi G. S. 
Published: October 2018

Abstract
Over the years, drillstring vibrations have become a major issue in the oil and gas industry. The search for energy has led operators to encounter various unconventional conditions such as high temperature, high pressure, etc. in their quest for oil and gas. Drillstring vibrations amongst other problems are regularly encountered in such conditions, leading to tool damage, increased downtime and other adverse problems. In this work, an analytical approach was adopted to investigate the major parameters that affect drillstring vibrations and a viable control method was recommended. The vibration models were analyzed and a modified model was developed to fit the standard drilling conditions, starting from the top of the drillstring down to the formation being drilled. Considering the Parameters which were often neglected in the works of this nature such as mud density and formation fracture pressure were investigated in order to understand the extent of their contributions to drillstring vibrations. Using standard drilling conditions for the simulations, we were able to identify the key parameters which significantly affected the vibration profiles. The data obtained from the simulations were used to obtain a markedly better profile which showed a marked reduction in amplitude. The analysis of the effect of all considered parameters to the vibration profile led to the conclusion that weight on bit / torque on bit and rotary speed are the key factors that affect drill-string vibrations and that the density of the drilling fluid used make little or no difference why formation fracture gradient caused a reduction in drillstring vibration as it increases.
Rain Water Quality Evaluation in a Typical Gas Flaring Environment in the Niger Delta
Authors: Ogolo Naomi Amoni , Ugwu Paschal , Ukut Imo , Otokpa Martins , Onyekonwu Mike 
Published: October 2018

Abstract
Environmental pollution is one of the major consequences of gas flaring. In the rural oil producing communities of the Niger Delta where this age long practice is common and a large portion of the population use rain water for domestic activities, it is imperative to evaluate the rain water quality in these environments. In this work, a hundred samples of rain water were collected within a period of two years from a typical community where gas flaring has been dominant for several decades. The samples were analyzed in the laboratory for pH value, turbidity and nitrite content, and the results were compared against the World Health Organization (WHO) standard for water quality.
The study shows that the rainwater samples collected from the gas flaring zone had an average turbidity value of 22.58NTU, an average pH value of 6.75 and contained an average of 2.6mg/l of nitrite. However, when considered separately, some rain water samples met the WHO standard while others did not. It was observed that about 61% of the samples considered met the WHO standard on turbidity of 15NTU for rain water and 17% of the samples met the standard for drinking water which is 5NTU. 26% met the lower pH standard of 7.0 for drinking water while 64% met the pH standard of 6.5 for rain water. 60% met the WHO requirement for nitrite content of 3mg/l but generally, about 39% of the samples did not meet the WHO standard for rain water quality. These test parameters indicate that the level of rain water pollution in this gas flaring environment is high and unhealthy especially for the ecosystem system. Thus, drastic measures need to be taken to stall gas flaring in the Niger Delta.
Fatigue Risk Management: Effective Solution to Workplace Stress in the Petroleum Industry
Authors: Linda Dennar , Nsikak Ntia , Afolabi Iboh , Folusho Alamina , Nayagawa Mbursa J. , Chima Emelle , Suleiman Ahmed 
Published: October 2018

Abstract
The nature of operations in the petroleum industry involves a significant amount of process and personal safety risks. Industry operators and service providers desire to achieve the safety goal of no fatalities or harm to personnel, and no damage to assets and environment.
Most operating companies and service providers have over time developed well-structured frameworks for Process Safety Risk Management. Aspects of personal safety especially operations-related are also well managed. A significant number of incidents have resulted from human factors related to stress and fatigue. Fatigue is a state of sleepiness with the associated lack of mental alertness caused by sleep deprivation. It is imperative that the industry recognizes the threat posed by fatigue and put the right measures in place to minimize the associated risks.
This paper intends to raise awareness on the impact of fatigue in the petroleum industry and recommend a framework for Fatigue Risk Management (FRM). A structured framework entails embedding of FRM Systems, which include studies, gap analysis, closure plans, and development of FRM plans, implementation, audits, and reviews.
The FRM system will ensure a safe working environment using a risk model to review outcomes and recommend actions. The embedment of this system which is based on Safety Management System (SMS) in the workplace ensures appropriate mitigations, effective controls, timely implementation, periodic audits and reviews. This system may be deployed in all areas of petroleum industry operations spanning Exploration and Production to the downstream sector. Similar models have been deployed in other industries with success.
Towards Transparency: Best Practices for Improving Community-Company Relations in the Nigerian Oil and Gas Sector
Authors: Ante M. A. , Ante A. E. 
Published: October 2018

Abstract
Oil and gas exploitation is a process of varied steps from prospecting and exploration to the production stage. As such, the overall success of such venture is dependent on success at each of these stages. While every step is critical, we highlight the important phase of community/company relations, which in fact is not a phase/step but a continuous aspect of the exploitation process as long as a company undertakes oil and gas development work in the community and even afterwards. Issues of land acquisition, memoranda of understanding, environmental issues and technical transparency (without disclosure of proprietary information) have increasingly caused misunderstanding and led to impasse which are detrimental to the causes of all parties involved. The objective of this work is to drive towards a sweet spot where the community and company can coexist for mutual economic attainment.
In the lens of a Petroleum Engineer and a Lawyer, we review current practices and best-practices and proffer better solutions on improving community-company relations tailored to the Nigerian sphere based on knowledge of our clime. Under applicable laws, acts and regulations, we review the nature of land acquisition and where errors have been made in this area causing discord; as regards memoranda of understanding we highlight standards for social and environmental outcomes. We also cover operational and environmental issues and how best these could be addressed on the engineering angle
We recognize that just like no two developmental projects are the same, there is therefore no one-size- fits-all solution but instead, guidelines and better understanding of issues from the technical angle and from the perspective of the law will help to remove the veil of mistrust and help communities and companies achieve a positive discourse at the table.
As we mark 60 years of oil production, the oil and gas industry has and will continue to be a major driver of economic growth in Nigeria. As such, it is necessary to model what real, perceived and impactful community-company partnership is composed of. Success at the community-company level will no doubt provide a foundation for success at the other levels of development and in turn grow our communities, its economy and people and our great nation, Nigeria, at large.
Optimization Of The Production Of High Quality Gasoline Blend From Different Oxygenates
Authors: Oduola M. K. , Nwangwu C. N. 
Published: October 2018

Abstract
Gasoline is a highly flammable liquid derived mainly from crude oil that is used primarily as an energy source for internal combustion engines. To be competitive, gasoline must meet certain standards of high quality such as Octane number, Ried Vapor Pressure (RVP), and minimal environmental pollutions. This work aims at optimizing the production of a high-quality gasoline blend that meets the Octane number, RVP, Economic and Environmental standards, using varying oxygenates. The gasoline blending was executed by employing the linear programming solver application in Microsoft excel using four blending components namely the Fluid catalytic cracking gasoline (FCCG), Straight run naphtha (SRN), Straight run gasoline (SRG), Butane, and varying Oxygenates. The Blending process was simulated in ASPEN HYSYS simulation software, and the output product was tested for pollutant emissions in the same software. The selected blend was further optimized to minimize emission using the Response Surface Methodology in MINITAB version 18. Upon gasoline blending optimization and emissions testing, four blends met our specifications namely, the MTBE blend, the ETBE-blend, the Ethanol-blend, 1-Butanol blend. After a simple weighting method, the Ethanol was selected as the optimal blend having a net savings of 67.09 tons/year and 476tons/year of NOx and TVOC emissions respectively, a net increase of 16.35 tons/year of TTC emissions. The Blend was further optimized using RSM. The optimization results showed that SRG was the main contributor to NOx emissions, ethanol was a significant contributor to the TTC emissions while Butane had no effect of both emissions. The new optimized ethanol-blend gave a further 90.42% reduction in NOx emissions, and 67.85% reduction in TTC emissions, but with an increased amount of ethanol in the blend. The economics of a gasoline blending plant was evaluated, giving a pay-back period of 2.46 year, NPV @ 10th year of $177.6 million, an internal rate of return of 57.36%, and a profitability index of 3.04. This showed that the process would be highly profitable.
Impact of Salinity on Oil Recovery during Waterflooding: An Experimental Approach
Authors: Stanley Okafor Ikechukwu , Ebenezer Ubani Chikwendu , Obi Onyekonwu Mike 
Published: October 2018

Abstract
Improving the recovery factor of conventional oil reservoirs is a critical factor in offsetting the inevitable decline of oil fields and keeping step with the world's demand for hydrocarbons. This paper describes a laboratory experiment to investigate the impact of brine salinity on oil recovery during waterflooding and to ascertain if there exist any relationship between salinity and type of oil in terms of recovery. During the flooding experiment, the cores were individually flooded with the high salinity and low salinity recovery brines in a secondary stage recovery process, to recover the crude oil (heavy and light) with which they were earlier saturated with. Recovery brine salinity ranged from 5000ppm to 30000ppm and a distilled water of 0ppm. Results obtained showed that high salinity recovery brine showed better recovery than the low salinity brine, for both the heavy and light oil. The high salinity brine recovered 61% and 63% of the heavy and light oil in place respectively, while the low salinity brine recovered 51% and 56% of the heavy and light oil in place. The results obtained are attributed to reduction in viscosity ratio, wettability alteration, reduction in interfacial tension and natural variations between cores. There was no definite relationship between crude oil type and the salinity of injected brines. It is recommended that studies to investigate the impact of salinity on cores containing clays should be carried out. These studies if successful will help in our bid to increase recovery factor during secondary recovery of the stranded oils in discovered fields.
Uncertainty Modelling in Multi-Layered Reserve Estimation Using Monte Carlo Simulation
Authors: Inuwa Mohammed Auwalu , Abdurahman Hassan , Dodo Ibrahim Sulaiman , Mohammed Adamu Bello 
Published: October 2018

Abstract
Risk and uncertainty are important aspects in petroleum engineering, which must be analysed and considered in reserve estimation. The petrophysical parameters such as porosity, permeability, saturation, net thickness and acreage that are pertinent to volumetric reserve estimate are measured with some degree of uncertainty and error. Data sources and means of acquiring data may also result in uncertainties in reserve estimation and forecasting reserve. However, oil and gas companies are indeed concerned with accurate oil and gas reserves and original hydrocarbon in place. In addition, they are interested in recoverable reserve and the time for the recovery process with certain degree of certainty and accuracy. These estimates are rarely accurate or the level of uncertainty sometimes make oil and gas project not economically profitable.
The two established volumetric methods of reserve estimation are deterministic and stochastic. In both approaches, mathematical formulae are used to estimate volumes of hydrocarbon. However, the deterministic approach uses single value input parameters that are considered representative of the reservoir. Thus, the corresponding volumetric value obtained is a single best-estimate. On the other hand, stochastic reserve estimation considers the fact that each parameter cannot be represented with a single value due to the uncertainty and heterogeneities associated with these parameters, but it should be included in an interval and model using appropriate normal, lognormal, or triangular distributions.
In this study, uncertainty in multi- layered volumetric reserve estimate was quantified using Monte Carlo simulation for all the uncertain parameters, and the total recoverable oil obtained from deterministic method subjected to the Oracle Crystal Ball software for sensitivity analysis. Pessimistic, most likely and optimistic reserve values were obtained with their respective certainty for all the simulation scenarios. Error parameters such as Standard deviation, mean, variance, skewness, kurtosis, and mean standard error were quantified. Very low value of 0.00241 as coefficient of variation indicated that there was a high level of confidence in this estimation based on the modelling of input parameters; and this resulted to 90%, 50% and 10% probabilities of the oil in place calculation as (130.22MMSTB), (88.31MMSTB) and (58.13MMSTB) respectively. Therefore, use of Monte Carlo simulation to modelled risk and uncertainty would increase investors' confidence, and reduce the risk and uncertainty associated with reserve estimates in general terms.
Nigerian National Petroleum Fiscal Policy – Fiscal Levers & Attendant Impact on Value of Oil Projects
Authors: Segun-Oki Hakeem , Lawal Hafiz , Filani Oladapo 
Published: October 2018

Abstract
Efforts to reform the Nigerian Petroleum Industry have been ongoing since 2008 when the Petroleum Industry Bill (PIB) was presented to the 6th National Assembly. The PIB was conceived to address three central themes which coexist in a delicate equilibrium: increase economic rent to government, resolve long standing socio-environmental issues and encourage a stable investment climate.
However, due to a lack of traction in passing the bill in its all-encompassing form, in 2016 the current administration took the judicious approach of splitting the PIB into four bills to expedite assent to law. One of which is the Petroleum Fiscal Framework Bill (PFFB). This Bill tables the National Petroleum Fiscal Policy (NPFP) as the go-forward fiscal framework for the Nigerian Petroleum Industry.
Industry consultation on the draft NPFP is currently ongoing, being led by industry trade groups such as the Oil Producers Trade Section (OPTS) and the Independent Petroleum Producers Group (IPPG). The outcome of these consultations will be incorporated into the final version of the PFFB to be enacted into law.
This paper makes both a quantitative and qualitative analysis of the impact provisions in the draft NPFP have on the value of oil projects under Production Sharing Contracts (PSC). It proffers mechanisms for arriving at a balanced fiscal package that ensures both the host government and investors receive fair value.