bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving Hole Cleaning Efficiency using Nanosilica in Water-Based Drilling Mud
Authors: Gbadamosi Afeez O. , Junin Radzuan , Oseh Jeffrey O. , Agi Augustine , Yekeen Nurudeen , Abdalla Yassir , Ogiriki Shadrach O. , Yusuff Adeyinka S. 
Published: October 2018

Abstract
Inadequate wellbore cleaning contributes to several major drilling problems such as; increase in torque and drag that can limit the reach to target, mechanical pipe sticking, difficulties in casing and cementing and logging operations that can increase well cost significantly. Meanwhile, effective removal of drilled cuttings from the wellbore improves penetration rate and drilling efficiency. Herein, water-based mud was formulated with nanosilica to enhance cuttings and solid particles transport from the wellbore to the surface. Four different weight percent concentrations of nanosilica (0.001, 0.003, 0.005 and 0.01 wt.%) at three different flow rates in litres/seconds (0.4, 0.6 and 1.0) and cutting size (small, medium and large) were used to investigate the formulated water-based mud lifting capacity of the drilled cuttings and other solid particles. Thereafter, the hole cleaning efficiency of the water-based mud containing nanosilica was compared to conventional water-based mud. The results show that nanosilica water-based mud influences the cuttings lifting capacity. The addition of the nanosilica concentrations to the water-based mud enhances the viscosity, thereby increasing the muds carrying and circulating capacity. Moreover, nanosilica water-based mud displays mud stability that will stabilize the wellbore and prevent the intrusion of formation fluids into it when compared with the conventinal water-based mud. The effect of cuttings size on the wellbore cleaning is minimal. The large cuttings size shows a lower degree of cuttings transportation compared with the small and medium cutting size. The small cuttings size has higher cuttings recovery to the surface. Finally, though increase in flowrate leads to more cuttings recovery, there is every tendency that much fluid flow rate will cause an increase in frictional pressure losses and equivalent circulating density, high pump pressure requirement and potential hole erosion.
Structured Benchmarking Approach for High Complexity Wells: A Case Study of Bonga Wells
Authors: Ezenwanne Elesie O. , Giadom Bari-Dumene 
Published: October 2018

Abstract
The approach to determining the proper benchmark dataset for checking the competitiveness of high complexity wells should involve a systematic definition of the well complexity variables that have a direct impact on the performance of the well.
What makes a well complex and how their competitiveness can be measured against similar wells is a thing of debate. Ranking wells on a universal scale of complexity is itself difficult and controversial as there are several factors that define how complex a well is.
Traditional methods of benchmarking assess the competitiveness of a drilling operation by plotting the performance variable against an independent variable (typically drilled interval). But drilled interval is only one element of complexity.
A few literatures have defined well complexity in terms of the ratio of measured depth to true vertical depth. Other literatures have also recognized factors that impact well complexity such as the type of well profile, kick-off point, long and highly inclined tangent sections, horizontal displacement, water depth, pressure gradients etc. A combination of these factors has been identified to lead to increased complexities in a well. Thus, the ability to measure the competitiveness of extended reach wells has become increasingly difficult.
This paper has been divided into two sections to explore several techniques for defining well complexity and address the challenge with finding the right benchmark dataset to assess the competitiveness of complex wells. Based on the outcome of the analysis, a structured classification of well complexities will be generated for input to benchmarking categorization for high complexity wells. This will thus, enable the prediction of the future performance of wells with higher complexities than conventional wells.
Viability of SiO2 Nanoparticles for Enhanced Oil Recovery in the Niger Delta: A Comparative Analysis
Authors: Ajulibe Daniel , Ogolo Naomi , Ikiensikimama Sunday 
Published: October 2018

Abstract
Based on the consistent laboratory success of SiO2 and its compatibility with sandstone reservoirs, it has been widely recommended for enhanced oil recovery (EOR). However, the economics must be commensurate with acceptable returns on investment given the current market realities. This study was focused on determining the economic advantage of SiO2 Nano-Fluid flooding for enhanced oil recovery in the Niger Delta as a tool for quality investment decision.
To achieve this, a comparative economic analysis was performed by evaluating economic feasibility of Alkaline Surfactant Polymer (ASP) Flooding, Water Alternating Gas (WAG) and SiO2 Nano-Fluid Flooding using a discounted net cash flow model for the Niger Delta and the recovery factors for the compared alternatives obtained from core-flood experiments. Economic indicators including Net Present Value (NPV), Internal Rate of Return (IRR), Profitability Index (PI) and Discounted Payback Period were used in ranking the alternative recovery methods based on their performance; and sensitivity analysis on some model inputs performed to observe their effect on the NPV of investment returns.
From the results obtained, SiO2 Nano-Fluid Flooding had an NPV of $57.88M with a payback period of 2 years. A profitability index of 1.83 and an internal rate of return of 75% with a hurdle rate of 15% was also observed for this option. ASP and WAG had NPVs of $15.45M and $25.3M respectively, with an internal rate of return above the hurdle rate. The results indicated that while all 3 compared alternatives are profitable for the Niger Delta, SiO2 Nano-Fluid flooding is potentially the most profitable. The consideration of this result and a subsequent implementation would be of advantage to oil producing companies in the Niger-Delta and provide a basis for the local manufacture of SiO2 Nano-particles.
Empirical Correlation for Estimation of the Vapourized Oil-Gas Ratio for Gas-Condensate Systems
Authors: Molokwu V. C. , Makinde O. M. , Onyekonwu M. O. 
Published: October 2018

Abstract
The increasing interest in production from liquid-rich reservoirs calls for an efficient method for estimating its fluid properties and more importantly, from production data. The gas material balance for liquid rich systems is largely dependent on several PVT parameters. One of such parameters is the vapourized oil-gas ratio, which defines the amount of stock tank condensate that drops from one standard cubic feet of produced well stream gas. The vapourized oil-gas ratio is usually obtained by Extended Black Oil simulation using an Equation of State (EOS) model well tuned to the PVT experimental data. This experimental data might not be readily available when needed for a quick analysis and even when available, the process of tuning requires great skill and experience of the reservoir engineer. An empirical correlation for the vapourized oil-gas ration is proposed based on a statistical evaluation of values obtained from several simulations (Extended Black Oil) using a tuned Equation of State Model. 14 representative gas-condensate samples from the Niger Delta were used to generate over 2000 lines of vapourized oil-gas ratio. The developed correlation have input parameters, which are readily obtained from field production data. This approach is easily applicable, and valid for a wide range of gas-condensate compositions. It predicts, to a good extent, the vapourized oil-gas ratio for a pressure depletion sequence without recourse to a rigorous EOS modelling.
The New-Dawn for Liquefied Natural Gas Utilization: Empowering the Transportation Sector in Nigeria
Authors: Nwosi Hezekiah Andrew , Appah Dulu , Kinigoma Boma 
Published: October 2018

Abstract
It is a recurrent decimal that conventional transportation fuel is becoming a scarce commodity in Nigeria. Owing to Oil refineries producing below designed capacity and not meeting with demand for transportation fuel in the country. This has been investigated to result from weak maintenance culture, technical issues and increase in population etc. The result has led to several man-hour losses, overdependence on foreign imported refined products and many more not to mention. Presently, production network processes via the transportation sector has been hindered due to the paucity sustainability of fuel supply. Auspiciously, Nigeria holds an abundant of Natural Gas deposits of 187tcf proven reserves which is underutilized in several sectors, especially the transportation sector which accommodate about 75% of the total energy usage in the country. Hence, the idea of using LNG as a transportation fuel is well-thought-out. This paper looks at the thermodynamic effect and computational fluid considerations involved in applying the LNG as a transportation fuel to attain longer distance travel. A numerical simulation was conducted using Finite Element Analysis (FEA) to determine the pressure distribution of the cryogenic tanks as well as the thermal effect of atmospheric disturbances through computational fluid dynamics. The result of atmospheric temperature is measured to be 25°C and as a result inlet velocity is set at 183.2 K. The LNG temperature initialized at −155, while the tank pressure equals 1.2bar. The tank heating and the heat flux is simulated for 5 hours per day km. Initial volume of LNG cryogenic storage tank is 60 liters, initial LNG temperature of 162°c, heat leakage per hour each day were measured to be 1.3 W and 1 bar, respectively. Initial mass flow rates of LNG Boil-off gas production (kg) 1%, 1.2%, 1.4%, 1.6% and 1.8%. Atmospheric Heat (KJ/h) and Mass Flow Rate the results are 0%, 0%, 0.000187% 0.000551% and 0.0009262% respectively. LNG can be used to transport vehicles to a very long distance of 1300Km without re-fill. Finally, the likelihood of utilizing LNG as a transportation fuel will be of immense economic and environmental benefit over Gasoline, diesel and CNG to the midstream sector.
Application of Competitive Scoping in Data Acquisition Plan Using Value of Information VOI
Authors: Awasthi Amit , Joshua Itua , Das Anindya 
Published: October 2018

Abstract
The cost of acquiring formation evaluation data is responsible for a significant portion of well costs. In the volatile oil price world, the well data acquisition programs have come under severe scrutiny to ensure adequate value is generated from every dollar spent. To support the process, generic Value of Information (VOI) analysis modules were developed to help justify data acquisition. Critical to the correct use of the modules is a good understanding of the key uncertainties, relevant business/operations decisions and associated data required to reduce uncertainties. The application of the modules on a typical shallow-water development well resulted in circa 20% cost reduction. Furthermore, this workflow has the potential to be replicated on a bigger scale (i.e. on more wells) in a bid to reduce field development costs.
Investigating the Potential Use of Waste Vegetable Oils to Produce Synthetic Base Fluids for Drilling Mud Formulation
Authors: Dankwa O. K. , Ackumey S. S. , Amorin R. 
Published: October 2018

Abstract
The environmental challenges posed by conventional oil-based drilling fluids along with legislation associated with their use have necessitated the development of synthetic organic liquids that are designed to improve environmental protection. In this research, waste/used oils from restaurants and food joints have been tested for their potential use as synthetic based fluids through rheological analysis. Physiochemical properties of the waste vegetable oil were determined; density: 0.88g/cm3, acid value: 64.8mg KOH/g of oil and Free Fatty Acid (FFA) content: 32.4%. The optimum conditioning of biodiesel production from waste oil was in two-step catalysed process. In the first step, sulfuric acid was used as a catalyst for esterification reaction to reduce acid value of the oil below 3mg KOH/g which was with different dosages. The next step was the base catalysed transesterification process which converted the pre-treated oil into biodiesel and glycerol in the presence of methanol and NaOH at varied reaction conditions. Density of 9.1 lb/gal and rheological properties; Yield Point (17 Ib/100ft2, 2 Ib/100ft2 and 2 Ib/100ft2), Plastic Viscosity (17cP, 8cP and 6cP), Gel strength at 10Ȳ (3 Ib/100ft2, 2 Ib/100ft2 and 2 Ib/100ft2) and Gel strength at 10″ (5 Ib/100ft2, 4 Ib/100ft2 and 2 Ib/100ft2) were all determined at temperatures of 80°F, 120°F and 160°F respectively. The formulated mud showed that biodiesel is a promising synthetic based fluid and has most of its rheological properties meeting the API standard. Though the initial cost of conditioning biodiesel will be quite high, it can be offset by its disposal cost as compared to that of diesel.
Effect of Salinity and Divalent Ions on Local Bio Polymers
Authors: Obuebite A. A. , Onyekonwu M. O. , Akaranta O. , Uzoho C. U. 
Published: October 2018

Abstract
Polymer flooding, an aspect of Chemical Enhanced Oil Recovery has proven to be effective in mobilizing residual oil and increasing sweep efficiency thereby contributing to an additional oil recovery of about 20%. However, recent studies have shown that local materials capable of acting as biopolymers have high potentials in enhancing oil recovery. This has attracted more interest due to their low cost, availability and environmentally friendly nature. This study seeks to evaluate the effect of polymer concentration, salinity and divalent ions on local biopolymers.
Three different local biopolymers namely Okro (Abelmoschus Esculentus), Ewedu leaf (Corchorus) and Editan leaf (Lasianthera Africana) was evaluated in the laboratory at varying concentrations. Two high salinity synthetic brines, labelled Soft Brine and Hard brine was also prepared in the laboratory to simulate actual formation brine. Aqueous stability and salinity scan experiments were conducted to determine compatibility and salinity tolerance of the local biopolymers with the different brines. Unconsolidated sand-packs oil displacement experiment was performed with medium crude using local polymer prepared in soft brine and hard brine solution to determine the effectiveness of the polymers.
Results showed that the various local polymers were compatible with soft brine, while compatibility with hard brine was highly controlled by the pH. As the brine salinity increased, the pH of the biopolymer concentration decreased. More so, as the concentration of the local polymer increased from 1000ppm-5000ppm, the displacement efficiency for each of the polymers increased. The effect of salinity during flooding showed that at higher salinity, the recoverability of the various polymer decreased. Sand pack flooding results showed that of the three local polymers, 0.5wt% Okro (Abelmoschus esculentus) gave the highest additional recovery of 23.4%OOIP. Polymer flooding with soft brine gave a higher displacement efficiency compared to hard brine flooding due to the presence of divalent ions with magnesium ions having the greater effect. This study supports the fact that at increased salinity and the presence of divalent ions leads to mechanical degradation of the local polymer which reduces the viscosity and increases the adsorption of the polymer solution thereby reducing the sweep/displacement efficiency of the polymer.
Application of Pressure Transient Well-Test to Geologic Reservoir Characterization of a Turbidite Reservoir in the West African Transform Margin Basin Offshore Cote d'Ivoire
Authors: Keshinro Olalekan , Adeyemi Quadri Arasi , Oni Olugbenga , Sonibare Wasiu , Ramaswamy Sunil 
Published: October 2018

Abstract
Building static reservoir model that realistically captures facies heterogeneities relies on detailed interpretations of the sand body architectures from the integration of subsurface datasets and analogue examples. The delineation of stacked channelized turbidite sands was carried out, based on detailed petrophysical analysis, well log correlation and seismic interpretations. The continuity and connectivity of these sands remain a challenge despite having carried out detailed seismic attribute analysis for sand fairways mapping. For this study, we used a combination of well logs correlation and pressure transient analysis to resolve the sand connectivity and continuity challenges.
Pressure transient analysis can be used to achieve both well productivity analysis and reservoir dynamic descriptive analysis. Interpretation of pressure transient well test can be done either by type curve matching or log-log derivative plot. A combination of log-log derivative plot and the Tiab Direct Synthesis (TDS) method were used to analyze the well test data. A log-log derivative plot is a plot of the pressure derivative against time with both axes on a logarithmic scale. Different geologic features such as faults, fractures and sand channels show unique fingerprint on the log-log derivative plots.
The distance of the channel sand from the well was estimated using the Tiab Direct Synthesis method by making use of the gradient of the channel fingerprint on the log-log-derivative plot.
The well test data from two wells at approximately 2.5km apart were plotted on the log-log derivative plot in other to identify the nature of the geologic features around the wells. In one of the well, channel sand signature or fingerprint was seen and the other well was not tested long enough to see the channel sand signature on the log-log derivative plot. The gradient from the channel sand signature on the log-log derivative plot was used in the TDS model to estimate the distance of the channel sand from the well. The TDS model estimated the distance of the channel sand from the well to be 51m. Based on the result of the pressure transient test analysis, we could establish that the sand is not continuously connected between the two wells. In combination with well logs correlation and seismic attribute analysis, the established sand fairways and baffles thus led to robust geological models with petrophysical properties that capture properly the lateral heterogeneity in the field.
Coring Unconsolidated Formations under Challenging Drilling Conditions – A Case Study, Swamp- Niger Delta.
Authors: Onyeji J. A , Abdullahi N. U , Owoyemi B , Ekun O. A , Akhigbemen E , Ajaegwu N 
Published: October 2018

Abstract
In the drive for excellent reservoir management practices and optimizing oil and gas production through efficient reservoir performance, the role of conventional coring cannot be overemphasized. Core data provides most representative and relevant data for the interpretation and understanding of the subsurface. Continuous coring techniques were deployed in the study area to obtain high quality cores for analysis and reservoir characterization of the productive intervals and development of appropriate enhanced oil recovery strategy. The reservoir cored is characterized as poorly consolidated sandstone reservoir comprising of a calcite roof, moderately sorted and very fine-grained, friable and laminated with shale. A thick column of shale intercalation separates the reservoir into upper and lower lobes. Generally, the formations were characterized as weak with the sand minimum stress of 7.5ppg to 11.0ppg and shale collapse pressure of 8.5ppg to 11.5ppg. Some of the challenges encountered in coring this reservoir includes but not limited to the following: Well collision issues, wellbore instability, depleted reservoirs, selection of effective coring bottom hole assembly and drilling fluid as well as rig space constraints. This paper presents how innovative techniques aided in mitigating the challenging drilling conditions. The systematic approach deployed comprises the use of gyro survey while drilling (GWD), anti-collision analysis, utilization of well-designed drilling fluid with low invasion properties that still maintain wellbore integrity and stability. A close monitoring of equivalent circulating density (ECD), use of fiberglass inner core barrel and low fluid invasion system that comprises core heads with special fluid pass ports to deviate flow away from already cut cores, and full core catcher system was employed. A detailed stratigraphic correlation with the offset wells to identify vital stratigraphic markers was carried out prior to coring. A 15 feet hole was drilled into the calcite roof of the reservoir with PDC bit and the hole cleaned prior to pulling out of hole with the drilling bottom hole assembly (BHA) to minimize the risk of core jamming. Cores were cut with special selected coring BHA using controlled coring parameters while plotting inverse rate of penetration (i-ROP). In addition, controlled trip out speed based on field experience, and proper core handling/ on-site core preservation was employed. The innovative approach resulted in achieving a recovery factor of more than 93 percent of high quality cores.
Benefits of Real Time Pressure Monitoring from Surface Read out Devices Case History- Zino Hub
Authors: Linda Dennar , Monday Nanpan , Olatubosun Aderibigbe , Chima Emelle , Onyinyechi Ekerendu , Uwem Essien , Amaraizu Odoemelam , John Oboh , Martins Amos 
Published: October 2018

Abstract
The Zino Hub is a very active gas hub within the Niger Delta region responsible for the delivery of major gas production and growth projects for key customers both in the export gas domain and IPP space. There are 38 producing gas wells completed across 19 reservoirs within this hub. These wells are pivotal to the delivery of gas to ensure the daily contractual agreements allotted to the hub is met. Due to the prolific and high level of gas deliverability within the hub, the Well, Reservoir and Facility Management Plan (WRFM) is highly prioritized, rigorously challenged and implemented.
As a part of the regulatory and WRFM fix the basics requirement, these reservoirs are monitored regularly to ensure they are produced under very healthy and acceptable reservoir practices. Yearly budget allocations for surveillance drives the quality and quantity of data acquired over these reservoirs. Over the years, the major source of pressure acquisition from these wells have been via gauges deployed through wireline. This of course has inherent challenges spanning from human resource deployment to acquisition sites in the face of current danger of kidnaps, high logistics cost and man power shortage, well site accessibility, unforeseen danger associated with well entries, inability to acquire data concurrently on demand without jeopardizing production (deferments) and many other threats such as escalated costs ensuing from community restiveness and demands
Recently, there has been a gradual shift from the wireline pressure acquisitions to the deployment of Permanent Down Hole Gauges with surface read out facilities for some of these wells. The value and convenience vis a vis the wireline deployment can never be over emphasized. On the front line is the cost reduction achieved in surveillance cost via these PDHG deployment. The interface feeders deliver well and reservoir data directly from the wells to the office there by facilitating insitu monitoring of reservoir and well parameters and very quick analysis are done to ensure healthy production of these wells within their operating envelopes. Well performance and diagnosis are done often on demand because consistent data is available daily.
The benefits accruing from this deployment is transparently contributing to a more robust, accurate and readily available data to the engineers and end users. This paper will highlight the obvious benefits of this deployment and, also recommend future improvements that would facilitate better analytical result.