bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytical Model for Estimation of Pore Volume to Breakthrough in Carbonate Acidizing with Organic and Mineral Acids
Authors: Lohrasb Sina , Junin Radzuan , Agi Augustine , Jaafar Mohd Zaidi , Gbadamosi Afeez , Sidek Mohd Akhmal , Gbonhinbor Jeffrey , Oseh Jeffrey , Yakasai Faruk 
Published: August 2021

Abstract
Acidizing is one of the most useful methods in the oil well stimulations. This treatment technique creates capillary wormholes in the carbonate formations to enhanced fluids flow production of a reservoir. One of the main indexes for recognizing the wormhole characterization is the pore volume to breakthrough number. Therefore, calculating this number is one of the main goals in the carbonate acidizing. Obtaining this number is always required for experimental works, which needs time, energy and cost. In this article, an empirical model was used to evaluate carbonate acidizing procedure in the limestone and dolomite cores as the carbonate cores. This empirical model measures the number of wormholes formed in the carbonate cores after acid injection by using the conservation of mass law. In this method, the transport relative reaction rates of acid and core inside the structure of wormhole was maintained during the wormhole creation process. Growing the wormhole in the carbonate formation was developed step by step. Changes in acid concentration as an injected fluid flow were accounted for in this empirical model. Also, the changes in carbonate porosity, the effect of Damköhler number, and injection rate were included in the model. Two types of carbonate rocks and five types of acids with different molar masses were used in this model for the analysis and validation of the model. The results from experimental works was significance and justifies the use of use of the law for mass transport and chemical reactions. Evaluation of the developed model with other experimental and numerical results gave an excellent assessment of 95.45% for the average accuracy and 0.9933 for the average coefficient of determination. Therefore, an empirical technique to approximate the pore volumes to breakthrough number in the limestone and dolomite cores with high accuracy using physical core and acid properties is proposed.
Delineating Depositional Environment through Lithostratigraphy and 2D Sequence Stratigraphy of a Typical Ramp Succession: In the Obom Field Niger Delta
Authors: Okobiebi Onome , Okobiebi Becky 
Published: August 2021

Abstract
Modelling the most appropriate depositional environment is essential in the reservoir characterisation and 3D modelling of oil bearing sands and the integration of various workflows reduces the uncertainty in deciding the appropriate depositional model which serves as a precursor into petrophysical property distribution during 3D modelling. This paper elaborates a robust study of the integration facies analysis, 2D sequence Stratigraphy and biostratigraphy data in depicting the environment of deposition of the OBOM field. The lithological description of the G8 to the F5 reservoirs ranged from finning upward sequence and blocky shaped sequence as channel sands and coursing upward shoreface deposits. Mineralogical descriptions of the penetrated sands were also carried out, especially on the F5 reservoir in which the presence of radioactive minerals was decisive to constrain the depositional environment to lower shoreface. In the Sequence stratigraphic analysis two 3rd Order depositional cycles was identified from top to bottom in the field. This is substantiated by the facies trend, facies cross plot and cycles indicators like maximum flooding surfaces identified by regional marker shales, biofacies population and biodiversity charts and sequence stratigraphic methods like sequence thickness, bed stacking patterns and facies depositional patterns with regards sea level change. It was noticed that reservoir thickness reduces from the bottom to the top with the proximal channel sands in deep intervals gradually overlain by distal upper shoreface sands and lower shoreface sands at the shallower intervals. The gross depositional environment was a transgressive marine settings ranging from the lower shoreface and channelized upper shoreface deposits. The results from the integration of facies analysis, biofacies, seismic analysis and sequence stratigraphy results reduces uncertainty in depositional environment models.
An Assessment of Opportunities and Challenges of Natural Gas Utilization in Ghana
Authors: Morgan Theresa Ahima , Oppong Dr.Riverson. Riverson 
Published: August 2021

Abstract
This study aims to contribute to industry discussion on gas utilization opportunities available to Ghana. Specifically, it will analyze Ghana's existing natural gas plans. i.e., the Gas Master Plan analyze possible opportunities and associated challenges and finally propose sources of finance for gas sector projects.
In order to discover opportunities of natural gas utilization as well as challenges that come in the course of implementation, data was sourced from secondary sources as well. Benchmarking was also done using the natural gas journeys of three (3) case study countries: Nigeria, China, and the United Kingdom and a comparative analysis compared their natural gas journeys in terms of policy direction, natural gas utilization, infrastructure development and challenges encountered vis a vis the natural gas journey of Ghana.
The analysis showed that various opportunities existed for natural gas utilization in the areas of industrial power generation, LNG export, CNG, Fertilizer and bauxite production. Various challenges such as lack of human and technical capacity, sector debt, regulatory issues, pricing issues, security of supply and others plagued most natural gas economies.
These findings suggest that an ‘armory’ of opportunities exist for natural gas utilization in Ghana. However, the implementation of these utilization options is contingent on the development of proper policy instruments and extensive investment in infrastructure. The country should also be conscious of bottlenecks that may hinder natural gas utilization efforts.
Impact of the Petroleum, Local Content and Local Participation Regulation 2013, Li 2204 on Local Skills Development in Ghana's Upstream Oil & Gas Sector
Authors: Oppong Riverson , Amoah-Awuah Nixon 
Published: August 2021

Abstract
This study was to assess how the implementation of LI 2201 has impacted the development of local skills in the sector. The study focused on the two producing International Oil Companies (IOCs) and the Petroleum Commission (PC). Data gathered were gathered using the mixed approach and analysed using descriptive analysis. The study revealed that the IOCs have put several initiatives in place to recruit and develop Ghanaians for key positions in their organization. These initiatives have resulted in forty six percent (46%) of Management staff, seventy four percent (74%) of Core Technical staff and ninety four percent (94%) of Other Support staff in their organisations combined being Ghanaians. The PC has also initiated a number of initiatives which are building the needed vocational skills as well as practical experience of Ghanaians and have led to localization of some positions within the sector.
Despite the successes achieve so far, there are challenges facing the PC and the IOCs which make it difficult for the sector to achieve the full intent of LI 2204. Key among the challenges are lack of required local skills, high skills development cost, lack of cooperation among key stakeholders and limited practical development opportunities which need to be addressed to be able to achieve the key intent of the Regulations. These challenges have been acknowledged by The PC and have set up an internal committee headed by the Director of Localisation to look into ways in which localization can be improved.
Modelling the Spread of Covid-19 in a Typical Oil and Gas Facility Setting
Authors: Okafor Emeka , Bass Brad 
Published: August 2021

Abstract
The spread of infectious diseases such as COVID-19 in a typical oil and gas facility setting, the health of employees, their families and their communities, is of real concern to the industry. In this work, a suitable predictive, agent-based model is used to predict the spread of COVID-19 in different settings as well as to evaluate strategies to block the spread. The agent-based modelling work is based on the simulation platform, Complex Organization and Bifurcation Within Environmental Bounds, or COBWEB. COBWEB simulates how a system of autonomous agents adapts to variation and sudden changes in the resource base or other features of their environment. Previous COBWEB simulation results illustrate that the tool is useful for predicting the evolution of COVID-19 spread and the effectiveness of various preventive actions including self-isolation of symptomatic people, social/physical distancing, effective PPE use, and ‘shielding’ (physical isolation) of the high-risk population. We adapted model parameters to better represent uncertainty about what might be expected in such a setting, in particular by shifting the distribution of risk severity towards ineffective PPE use, self-isolation and poor social distancing, which expectedly shows upward trend of the spread of the COVID-19. Ultimately, governments and industry can apply the predicted trends, as well as apply the model to specific settings, to make more informed decisions on the additional measures and preventative strategies to curb the spread of COVID-19.
Decommissioning of Offshore Oil and Gas Facilities: A Comparative Study Between Malaysia Practices and International Standards
Authors: Kumar Shaleni , Sidek Mohd-Akmal , Agi Augustine , Junin Radzuan , Jaafar Mohd-Zaidi , Gbadamosi Afeez , Gbonhinbor Jeffrey , Oseh Jeffrey , Yakasai Faruk 
Published: August 2021

Abstract
Regulations for decommissioning are bound by international and domestic regulations. There are numerous decommissioning concepts to choose from, such as complete or partial removal, structure severance options which leave behind shell mounds and drill cuttings. However, in several international regulations there appears to be little clarity and/or opposing ideologies. Malaysia and Thailand have accessible resources for decommissioning legislation or guidelines in South East Asia. Nevertheless, they are differences in the regulations of these countries regarding the legal framework, the technical, financial and environmental framework. In this study, the feasibility of existing framework in decommissioning process of offshore installations or structures in Malaysia was studied and compared with international practices. Decision matrix analysis was used to systematically identify, analyse, and rate the performance of relationships between sets of values and information. Moreover, the scale of decommissioning activities over the next years, the data and information obtained were analysed using descriptive statistics approach. The results indicated that Thailand had the best decommissioning regulations because they have strict regulation in decommissioning. Most of the regulations covering the technical section are similar within all countries studied. Finally, recommendations given are from the aspects of frameworks on in-situ full or partial decommissioning, clarity on liabilities and residual risk management, financial security, residual risk funds, workflow optimisation, information management system, and waste management.
Mechanically Enhanced Cementing: Mitigation Against Sustained Casing Pressure in Highly Stressed Downhole Environment, Offshore Niger Delta
Authors: Abdulsalaam Ilyas , Amos Chibuzor , Ahabike Grace , Ejukorlem-Okusi Rebecca 
Published: August 2021

Abstract
A major Exploration and Production (E & P) company was posed with a challenge of sustained casing pressure in over 85% of the wells drilled in one of the fields in the Offshore Niger Delta. Sustained casing pressure occurs when the annular seal is damaged and a path is created for the formation pressure to reach the surface, and the pressure in the annulus rebuilds after being bled down.
When cementing in such an environment, operators have the following objectives: Placing a cement sheath with increased capability to survive future downhole stress events.Achieving effective mud removal.Gaining the benefits of a react and respond sheath design.Providing a long productive life for the wellbore.
To develop a cement system that would achieve and maintain isolation throughout the life of the well, an advanced cement technology was required. This advanced cement technology involved Finite Element Analysis (FEA) to model the effects of stresses from well operations on the cement sheath.
This analysis takes into consideration well configuration, formation properties, casing properties, cement properties and operational loads and predicts the remaining capacities of the cement sheath. The remaining capacity is used to measure how much a cement sheath is stressed. After simulating the effect of downhole stresses on a cement sheath, a mechanically enhanced cement slurry was designed to meet the recommendations of the model and provide a cement sheath with improved remaining capacity.
This paper presents the successful mechanically enhanced slurry design, job design, planning and execution on the production section of the well after a Finite Element Analysis was conducted.
Post job conditions such as good cement bonds across cemented areas, well production without inter-zonal communication and no annular pressure build up in over 8 years have proven the success of the design and the procedure implemented in these challenging well bore environments. The success of this well has been applied to two additional wells.
Sequential Prediction of Drilling Fluid Loss Using Support Vector Machine and Decision Tree Methods
Authors: Rotimi Oluwatosin John , Ukwu David Nnaemeka , Zhenli Wang , Liang Yao , Ameloko Anthony A. , Ogunkunle Temitope Fred , Oyeyemi Kehinde David , Kouamelan Kouamelan Serge , Asaboro Ufouma Frank , Onuigbo Ifunanya Sylvia 
Published: August 2021

Abstract
Machine learning methods have been applied to predict depths of fluid loss in hydrocarbon exploration.During drilling, lost circulation can be described as the unpleasant loss of all or part of drilling mud or fluid into the immediate formations or affected formation by excessive hydrostatic pressure, sufficient to fracture the formation or expand existing fractures encountered during the drilling process. In this study, we deployed Python codes of Support Vector Machine (SVM) and Decision Tree (DT) methodsto categorical data obtained from drilling operations in a producing field to predict lost circulation occurrence. The modelsleveraged the capability of both SVM and DT to achieve binary classification by adopting flow-out percentage of less than 70 percent as the points of lost circulation. That is, &lt; 70% is represented as Loss and &gt; 70% represented asNo Loss. Prediction models were applied to 10 input variables preprocessed with principal component analysis (PCA) to reduce dimensionality and focus on essential variables. The preprocessed SVM model gave an improved result while preprocessing does not affect DT models. Overall, DT models predicted accurate fluid losszones and can be scaled up to field operations with options ofcontinuous sampled variables.
Managing Wellbore Stability Window and Well Integrity by Adjusting the Tight Margin to Successfully Drill through Naturally Fractured Zone Onshore Niger Delta
Authors: Akong Bassey , Orimoloye Samuel , Otutu Friday , Ojo Akinwale , Mfonnom Goodluck , Mrakpor Ovie , Obasuyi Edward , Samuel Ogba , Oladoyin Olumide 
Published: August 2021

Abstract
The analysis of wellbore stability in gas wells is vital for effective drilling operations, especially in Brown fields and for modern drilling technologies. Tensile failure mode of Wellbore stability problems usually occur when drilling through hydrocarbon formations such as shale, unconsolidated sandstone, sand units, natural fractured formations and HPHT formations with narrow safety mud window. These problems can significantly affect drilling time, costs and the whole drilling operations. In the case of the candidate onshore gas well Niger Delta, there was severe lost circulation events and gas cut mud while drilling. However, there was need for a consistent adjustment of the tight drilling margin, flow, and mud rheology to allow for effective filter-cake formation around the penetrated natural fractures and traversed depleted intervals without jeopardizing the well integrity. Several assumptions were validly made for formations with voids or natural fractures, because the presence of these geological features influenced rock anisotropic properties, wellbore stress concentration and failure behavior with end point of partial – to-total loss circulation events. This was a complicated phenomenon, because the pre-drilled stress distribution simulation around the candidate wellbore was investigated to be affected by factors such as rock properties, far-field principal stresses, wellbore trajectory, formation pore pressure, reservoir and drilling fluids properties and time without much interest on traversing through voids or naturally fractured layers. This study reviews the major causes of the severe losses encountered, the adopted fractured permeability mid-line mudweight window mitigation process, stress caging strategies and other operational decisions adopted to further salvage and drill through the naturally fractured and depleted intervals, hence regaining the well integrity by reducing NPT and promoting well-early-time-production for the onshore gas well Niger Delta.
Nigerian Gas Transportation Network Code NGTNC; Emerging Opportunities for Local Gas Transmission Operations
Authors: Bashir Shehu Umar , Idris Farouk , Usman Kamalluddeen 
Published: August 2021

Abstract
Historically, both regulatory and contractual constraints have inhibited the overall optimization of natural gas transmission systems. The Nigerian National Petroleum Corporation (NNPC) currently supplies gas either as source of fuel or as feedstock to different industries. More local industries are now aware of the advantages and benefits of using gas; hence creating an increase in demand. Recent changes in the regulatory framework and the introduction of the Nigeria Gas Transportation Network Code (NGTNC) to deepen the growth of gas market in the country are however, fostering the pipeline companies into a new competitive position, creating strong incentives as well as opportunities. This work provides a section-by-section summary of the Code for the benefit of those who are passionate about understanding the nuances of the Code and of course makes cogent survey and recommendations, to expedite the success of the Code. In the course of this research, questionnaires were administered and 130 respondents were chosen based on their level of knowledge and experience in the industry ranging from operations, management, regulatory and Gas Associations. Responses were collated and analysed using simple statistical tools, tables, and graphs to identify opportunities. The result of the study illustrates the stakeholder's presumption and commitments in using NGTNC for optimized Gas transmission operations.
Evaluation of Machine-Learning Tools for Predicting Sand Production
Authors: Ngwashi Afungchwi Ronald , Ogbe David O. , Udebhulu Dickson O. 
Published: August 2021

Abstract
Data analytics has only recently picked the interest of the oil and gas industry as it has made data visualization much simpler, faster, and cost-effective. This is driven by the promising innovative techniques in developing artificial intelligence and machine-learning tools to provide sustainable solutions to ever-increasing problems of the petroleum industry activities. Sand production is one of these real issues faced by the oil and gas industry. Understanding whether a well will produce sand or not is the foundation of every completion job in sandstone formations. The Niger Delta Province is a region characterized by friable and unconsolidated sandstones, therefore it's more prone to sanding. It is economically unattractive in this region to design sand equipment for a well that will not produce sand.
This paper is aimed at developing a fast and more accurate machine-learning algorithm to predict sanding in sandstone formations. A two-layered Artificial Neural Network (ANN) with back-propagation algorithm was developed using PYTHON programming language. The algorithm uses 11 geological and reservoir parameters that are associated with the onset of sanding. These parameters include depth, overburden, pore pressure, maximum and minimum horizontal stresses, well azimuth, well inclination, Poisson's ratio, Young's Modulus, friction angle, and shale content. Data typical of the Niger Delta were collected to validate the algorithm. The data was further split into a training set (70%) and a test set (30%). Statistical analyses of the data yielded correlations between the parameters and were plotted for better visualization.
The accuracy of the ANN algorithm is found to depend on the number of parameters, number of epochs, and the size of the data set. For a completion engineer, the answer to the question of whether or not a well will require sand production control is binary-either a well will produce sand or it does not. Support vector machines (SVM) are known to be better suited as the machine-learning tools for binary identification. This study also presents a comparative analysis between ANN and SVM models as tools for predicting sand production. Analysis of the Niger Delta data set indicated that SVM outperformed ANN model even when the training data set is sparse. Using the 30% test set, ANN gives an accuracy, precision, recall, and F1 - Score of about 80% while the SVM performance was 100% for the four metrics. It is then concluded that machine learning tools such as ANN with back-propagation and SVM are simple, accurate, and easy-to-use tools for effectively predicting sand production.