Niger Delta Crude Oil Research Articles

Modeling the Effect of Random Environmental Perturbation on Data Precision in Niger Delta Crude Oil Production

Decision-makers most times rely on data precision to support their decision-making processes. There is also a strong belief, however, that data quality or data precision problems are widespread in practice and that reliance on poor data quality or wrong data sets can lead to devastating consequences on crude oil production and financing. This study applies the Runge-Kutta numerical method of order 45 (ordinary differential equation of order 45) to examine the effect of data precision index on the Niger Delta crude oil production due to the variation of the initial condition. The study has found out that the initial condition four (4), (IC 4) with a data precision index value of 0.0118 ranked best in the first crude oil well, the initial condition (IC) 15 with a data precision index value of 0.0021 ranked best in the second crude oil well, the initial condition (IC) 17 with a data precision index value of 0.0021 ranked best in the third crude oil well and the initial condition (IC) 20 with a data precision index value of 0.0234 ranked best in the fourth crude oil well. The study has observed that each crude oil data is associated with a best-fit-value of the data precision index.

ECOLOGICAL AND HUMAN HEALTH RISKS ASSOCIATED WITH SOIL POLLUTION BY PAHS AND HEAVY METALS IN THE NIGER DELTA

Despite the prevalence of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in Niger Delta's crude oil regions, comprehensive research on their concentrations and combined risks in crude oil-contaminated soils is lacking. Our study focused on examining the concentration, source, spatial distribution, and health risk of 16 PAHs and 9different HMs in soils across a gradient of Niger Delta area Nigeria. The objective was to gain a comprehensive understanding of the HMs and PAHs' behavior in the environment and their potential impact on human health. The mean total concentrations of 16 PAHs (Σ16PAHs) were 779.58 ng/g for upland area, 749.46 ng/g for mid-slope area, and 679.37 ng g-1 for Low-land. The concentration of the HMs followed the order of Cu > Cd > Ni > Pb > Cr > Fe > Mn > Zn > Co, with Cu, Cd, Ni, and Pb exceeding the permissible levels. The study areas displayed varying concentrations of NO3-, PO42-, SO42- Ca, Na, and K, with some levels exceeding acceptable values, possibly influenced by crude oil contamination and the use of fertilizers. In the Niger Delta regions, the primary sources of soil PAH contamination include crude oil spills, natural crude oil seepage, and coal combustion. With this, the government of Nigeria should strengthen soil contamination monitoring, enforce spill regulations and promote eco-friendly farming.

Chemometric-enhanced geochemical characterisation of diamondoids in Niger Delta crude oils

Chemometric-enhanced geochemical characterisation of diamondoids in Niger Delta crude oils

Oil Formation Volume Factor Prediction Using Artificial Neural Network: A Case Study of Niger Delta Crudes

Artificial intelligence techniques provide an alternative to conventional empirical correlation methods when experimentally determined oil formation volume factors (OFVF) are lacking. A new mathematical model is proposed using an artificial neural network (ANN) for estimating the OFVF for the Niger Delta crude oils. The method consists of two stages: data decorrelation through principal component analysis (PCA) and OFVF estimation through ANN. Data decorrelation was used to reduce redundancy in the data which decreased the number of neurons in the hidden layer needed for an ANN to achieve high accuracy. In the development of the model, 316 data points were obtained from the Niger Delta region of Nigeria. Application of data cleaning, outliers’ elimination and PCA analysis reduced the data to 243 points. 213 data points were used to develop the model of which 75% was used for training, 15% for validation and 10% for testing. The remaining 30 data points were used to test the predictive capability of the proposed model. The results obtained were compared with widely accepted empirical correlations of Standing, Glaso, Vazquez, Ikiensikimama & Ajienka, and Al-Marhoun. The proposed new model performed better than all of them in terms of coefficient of correlation, AAPE and RMSE. Hence the ANN model will reduce cost, save time, and also predict the OFVF of Niger Delta crudes with higher precision.

Chemical Fingerprinting of Tricyclic Terpanes in Two Niger Delta Crude Oils and their Mixtures

Chemical Fingerprinting of Tricyclic Terpanes in Two Niger Delta Crude Oils and their Mixtures

Tricyclic Terpane Fingerprint of Crude Oils from Niger Delta, Nigeria

Tricyclic terpanes identified in two representative crude oils from the Central and Western Niger Delta (oil- RVAG and oil-DTIR, respectively) ranged from C19 to C29, including C24 tetracyclic terpane. Plot of the abundances of tricyclic terpanes show similarity in the distribution profile of the oil samples, characterized by the uncommon distribution of C20 and C21 tricyclic terpanes indicating both Niger Delta crude oils are derived from similar source organic matter. Ratios of C22/C21 and C24/C23 tricyclic terpanes indicate source rocks of the crude oil samples were deposited in a deltaic environment and derived from mixed marine/terrestrial organic matter. Additional, C26/C25 tricyclic terpanes, C24 tetracyclic/C23 tricyclic terpanes and C24 tetracyclic/C26 tricyclic terpanes indicate the crude oil samples are generated from shale source rocks derived from terrestrial organic matter, with oil-DTIR receiving a more terrestrial contribution, and marine facies, with oil-RVAG receiving a more marine contribution. Thermal maturity, determined from ratios of low to high molecular weight tricyclic terpanes, indicate the crude oil samples are mature with oil-RVAG more mature than oil-DTIR. The ratios of C19/C23 and C20/C23 tricyclic terpanes, which indicate high maturity of the crude oils, suggested terrestrial and marine source for oil-RVAG and oil-DTIR, respectively, contrasting with the relative abundances of tricyclic and tetracyclic terpanes. This implies the abundances of C19 and C20 tricyclic terpanes, particularly in crude oils at high maturity, as in the Niger Delta, has interfering effect on source interpretation and its ratios be used in combination with other parameters for evaluating Niger Delta crude oils.

The effect of polyethylene butene (PEB) and xylene on the shear stress of Niger delta crude oil

The effect of polyethylene butene (PEB) and xylene on the shear stress of Niger delta crude oil

The effect of polyethylene butene (PEB) and xylene on the shear stress of Niger delta crude oil

Crude oil production and transportation is plagued by several flow assurance issues especially in offshore environment with prevailing low temperature. One of the flow assurance challenges is the deposition of paraffin wax which usually changes the crude oil flow from Newtonian fluid flow to non- Newtonian fluid flow with increased viscosity. This increased viscosity can impede flow causing the installation of high horsepower pumps for fluid flow. In severe cases, paraffin wax has plugged the pipes and caused production disruption. It is therefore imperative to manage paraffin disposition in crude samples containing paraffin compounds (C18+). This research discusses the use of varying concentrations of Polyethylene Butene (PEB) in managing wax precipitation at various temperatures (10 °C to 35 °C) at a constant shear rate of 511(s-1). The reduction in crude oil temperature increased the shear stress in all experiments conducted. It was discovered that the increasing concentration of PEB from 500ppm to 5000ppm had a sinusoidal effect on reducing the shear stress. 500ppm of PEB effected a 19% reduction in shear stress, while 5000ppm effected a 35% reduction in shear stress. It is important for the engineer to make the choice of inhibitor concentration based on the degree of shear stress reduction required to optimize inhibitor usage.

Terpane Characterization of Crude Oils from Niger Delta, Nigeria: A Geochemical Appraisal

The geochemistry of crude oils from the Niger Delta, Nigeria, were evaluated using the characterization of C₁₉ to C₃₅ terpanes. Analyses of two representative crude oils from Western and Central Niger Delta showed abundances of C₁₉ to C₂₉ tricyclic terpanes constituted 12.09% and 29.74%, C₂₄ tetracyclic terpane 0.31% and 0.15% and C₂₇ to C₃₅ pentacyclic terpanes 87.61% and 70.12%, respectively. Diagnostic ratios of terpanes indicated relatively low abundances of C₂₃, C₂₈ and C₂₉ tricyclic terpanes, low abundances of homohopanes, a significantly high abundance of oleanane and that the Niger Delta crude oils were derived from terrestrial organic matter source rocks deposited in an oxic environment during the Tertiary period. Multivariate oil-oil correlation plot showed the Western and Central Niger Delta crude oils are not distinct, but moderately related (genetically). However, diagnostic ratios of C₂₄ tetracyclic terpane, which was high and moderate and gammacerane, which was low and high, revealed crude oils from Western Niger Delta were derived from predominantly terrestrial source and crude oils from Central Niger Delta were derived from terrestrial source with input from marine organic matter, respectively. Tricyclic terpanes/hopanes and isomerization ratios of C₃₂ homohopanes indicated the Niger Delta crude oils were generated at high maturity, at top of the oil generation window.

Chemometric Evaluation of Terpanes for Composition Allocation of Two Niger Delta Crude Oil Mixtures

Chemometric methods were employed to evaluate terpanes that correspond to the variations in the compositions of two Niger Delta crude oils (samples A-10 and F-00) in their mixes (samples B-82, C-64, D-46, and E- 28). Total abundances, plots, and hierarchical cluster analysis of C19 to C35 terpanes in the six oil samples suggest that the abundances and distributions of terpanes significantly correlated and did not mix correspondingly in the oil samples. Principal component analysis (PCA) showed that the first principal component (PC1) accounted for 95.77% of the total variance of individual terpanes among the oil samples with H30, OL, and NH30 explaining the most variance and NH25a, NH25b, and TR20d explaining the least variance, respectively. Plots of nine (9) ratios, derived from the most and least variant terpanes, gave R² values (0.4919 - 0.9749) that indicate the ratios moderately to very strongly correspond to the compositions of the two Niger Delta crude oils in the oil samples. Ratios of H30/H30+NH25b, OL/OL+NH25b and NH30/NH30+NH25b, with the highest R² values, showed very strong predictability (97.33%, 97.03% and 97.49%) for estimating the compositions of the two Niger Delta crude oils in their mixes.

Uncommon Distribution of C20 and C21 Tricyclic Terpanes in Niger Delta Crude Oils

C20 and C21 tricyclic terpanes were investigated in crude oils from Niger Delta, Nigeria. From comparison of the mass chromatograms (m/z 191) of two crude oil samples (CEN-21 and WST-69) with related literatures on tricyclic terpanes which eluted from the gas chromatography (GC) within certain retention time, 12 peaks were selected. Peaks 1 - 5 were selected as C20 tricyclic terpane isomers (TR20a-e) and peaks 6 - 12 selected as C21 tricyclic terpanes (TR21a-g). This distribution is usually as crude oils show a single peak each and indicate the distribution of C20 and C21 tricyclic terpanes in the Niger Delta crude oils is uncommon. Total abundances showed the C20 and the C21 tricyclic terpanes were more in CEN-21 than WST-69 with ratios of 3.07 and 1.84, respectively, with TR20a, TR20b, TR20d and TR21d being the most abundant isomers in both oil samples. These abundances indicate CEN-21 was thermally more mature than WST-69 and that the C20 tricyclic terpanes were generated more than the C21 tricyclic terpanes with increasing thermal maturity of the crude oils. Significant similarities observed in the normalized composition profiles and 66 derived ratios suggest the Niger Delta crude oil samples were genetically related and were predominantly derived from terrigenous Tertiary deltaic petroleum systems. Some differences observed in the composition profile and derived ratios indicate minor input from a different source, depositional environment and/or maturity level and are suggestive as indicators for evaluation, correlation and/or discrimination of the Niger Delta crude oils.

Can Crude Oil Exploration Influence the Phytochemicals and Bioactivity of Medicinal Plants? A Case of Nigerian Vernonia amygdalina and Ocimum gratissimum

The Nigerian Niger-Delta crude oil exploration often results in spills that affect indigenous medicinal plant biodiversity, likely changing the phytochemical profile of surviving species, their bioactivity or toxicity. In crude oil-rich Kokori and crude oil-free Abraka, classic examples of indigenous plants occupying the medicine-food interface include Vernonia amygdalina (VAL) and Ocimum gratissimum leaves (OGL). These plants are frequently utilised during pregnancy and in anaemia. To date, no scientific investigation has been reported on the potential changes to the phytochemical or bioactivity of the study plants. To discuss the similarities and dissimilarities in antisickling bioactivity and phytochemicals in VAL and OGL collected from Kokori (VAL-KK and OGL-KK) and Abraka (VAL-AB and OGL-AB), in silico, in vitro and comparative UPLC-QTOF-MS analysis was performed. Nine unique compounds were identified in OGL-KK, which have never been reported in the literature, while differences in antisickling potentials were observed in VAL-KK, OGL-KK and, VAL-AB, OGL-AB. Our findings show that VAL-AB and OGL-AB are richer and more diverse in phytochemicals and displayed a slightly higher antisickling activity than VAL-KK and OGL-KK. Ligand-based pharmacophore modelling was performed to understand the potential compounds better; this study may provide a basis for explaining the effect of crude oil spills on secondary metabolites and a reference for further research.

Support Vector Machine Model for Predicting Gas Saturated and Undersaturated Crude Oil Viscosity of Niger Delta Oil Reservoir

Oil viscosity is one of the most important physical and thermodynamic property used when considering reservoir simulation, production forecasting and enhanced oil recovery. Traditional experimental procedure is expensive and time consuming while correlations are replete however they are limited in precision, hence need for a new Machine Learning (ML) models to accurately quantify oil viscosity of Niger Delta crude oil.
 This work presents use of ML model to predict gas-saturated and undersaturated oil viscosities. The ML used is the Support Vector Machine (SVM), it is applicable for linear and non-linear problems, the algorithm creates a hyperplane that separates data into two classes. The model was developed using data sets collected from the Niger Delta oil field. The data set was used to train, cross-validate, and test the models for reliability and accuracy. Correlation of Coefficient, Average Absolute Relative Error (AARE) and Root Mean Square Error (RMSE) were used to evaluate the developed model and compared with other correlations.
 Result indicated that SVM model outperformed other empirical models revealing the accuracy and advantage SVM a ML technique over expensive empirical correlations.

The Occurrence and Distribution of Oleanane Biomarkers in Crude Oils as an Index

Oleanane biomarkers are age diagnostic indicators and source of organic matter input in fossil fuels which can unravels the stage of development of a petroleum system in the petroleum generating rock. Representative samples of crude oil obtained from two separate fields in the southern Nigeria province were evaluated geochemically using Gas Chromatography–Mass Spectrometry. The data obtained from the analysis of the crude oil samples revealed the presence of the 18α (H)-oleanane biomarker. The occurrence of 18α (H)-oleanane biomarker in the Niger Delta oils provides diagnostic evidence on age and organic matter source in all samples. The results of the Oleanane indices for all samples ranged from 0.32 to 1.03 (> 0.30), which suggests that the oils are from Tertiary age source rocks with resilient terrestrial organic matter input. Only crude oil sample KD03 had an Oleanane index of 0.03 (< 0.30), which shows crude oils derived from a late cretaceous or younger age with some marine input. The presence of 18α (H)-Oleanane in Niger Delta crude oils is a confirmation of an earlier postulation that most crude oils from the region had a greater terrestrial organic matter input.

Effect of poly (ethylene-butene) and nano-aluminium oxide blend on the viscosity of Nigerian crude oil

Wax deposition in production tubing and pipelines is very critical in Nigeria petroleum industry. It can lead to a reduction in production, shut-in of wells, choking of flow lines, failure of downhole equipment, increased power requirement and loss in revenue. In the bid to address this issue, a Niger Delta crude oil sample was characterized in this study to know its wax deposition tendency and other chemical properties. The effect of temperature on the viscosity of the crude oil sample was studied, and the degree of viscosity reduction (DVR) of the crude oil sample in the presence of poly (ethylene-butene) (PEB) and nano-aluminium oxide (Al2O3) blend at different temperatures was evaluated. 100 ppm of nano-Al2O3 blend with 1000 ppm, 2000 ppm and 5000 ppm of PEB, respectively, was added to the crude oil sample at different temperatures, and the degree of viscosity reduction (DVR) in each blend at 10 °C, 15 °C, 20 °C, 30 °C and 35 °C was evaluated. The blend with 2000 ppm of PEB with 100 ppm nano-Al2O3 is the best for offshore application as it gave the highest DVR of 77.9% and 73.7% at 10 °C and 15 °C, respectively, while the other blends gave a DVR of about 70% at 10 °C and 15 °C. As the crude sample temperature approached the wax appearance temperature of 29 °C, the DVR of PEB/Al2O3 blend drastically reduced. PEB/Al2O3 blend inhibited wax precipitation, and at low temperatures, a significant reduction in the viscosity of the crude oil sample was observed, which makes it a good recommendation for offshore application.

Geochemical Characterization of Two Niger Delta Crude Oils and Their Mixtures II: Correlation of Bulk Properties and Aliphatic Hydrocarbons

Correlations of bulk geochemical properties such as density, API gravity, saturates, aromatics, resins and asphaltenes (SARA) compositions, aliphatic hydrocarbons (from nC8 to nC38) and their diagnostic ratios (Pr/Ph, Pr/nC17 and Ph/nC18) were evaluated for two Niger Delta crude oils (samples A and F) and their mix at different proportions of 4:1, 3:2, 2:3 and 1: 4 (samples B, C, D and E respectively). Pearson correlation showed strong relationships (> 0.99) between sample pairs in their bulk geochemical properties and diagnostic ratios, but variable relationships (0.20 - 0.85) in the aliphatic hydrocarbons which increased with increase in the proportion of sample F. Assessment of aliphatic hydrocarbon compositions by hierarchical cluster analysis (HCA) showed two major groups of clearly differentiated clusters with negative similarity and their plots revealed the aliphatic hydrocarbon compositions increased/decreased from samples A to F and exhibited variable strength for correlation of the oil samples. Plots of ratios of the aliphatic hydrocarbons were used to depict the geochemical compositional variations of the oil samples. Coefficient of determination (R²) of the plots indicate the ratios C 14/C14 + C25, C15/C15 + C24 and C17/C17 + C23 fits well and could account for 99.4%, 99.3% and 99.2% of the geochemical compositional variations of the two Niger Delta crude oils and their proportional mix. The results suggest these aliphatic hydrocarbon ratios could be useful for estimating the composition of two Niger Delta crude oils in their mix.

Aromatic Hydrocarbons as Indicators of Maturation and Source: Correlative Geochemical Evaluation of Commingled Niger Delta Crude Oils

Two Niger Delta crude oils from Rivers and Delta States (samples A and F) and their compositional mixtures (samples B, C, D and E) where evaluated using a range of geochemical parameters derived from aromatic hydrocarbons and aromatic sulphur compounds to determine their source and maturity. The relative distribution of various plant markers in crude oil samples A and F which were retained in their compositional mixes suggests the contribution of angiosperm higher plants and coniferous higher plants to the source rocks that generated the crude oils. The various maturity parameters computed for the oil samples revealed that both the Rivers and Delta crude oils lie in the high maturity state with sample F significantly more matured than sample A. All alkynaphthalene maturity parameters suggested a peak to late oil generation window for the crude oil samples except the methyl naphthalene ratio (MNR) whose maturity sequence lacks sufficient variation to distinguish maturity differences in the crude oil samples. The maturity characters of TNR-1 and TNR-2 (trimethylnaphthalene ratio) showed a strong correlation between the individual crude oil samples and their mixtures. However, all the other maturity parameters showed moderate or weak correlation between the individual crude oil samples and their mixtures.

Influence of Heavy Organics Composition on Wax Properties and Flow Behavior of Waxy Crude Oils

Paraffinic crude oils are desirable because of their high content of saturated hydrocarbons but may present handling challenges due to crystallization of high molecular weight paraffin at low temperatures. The prediction of wax properties and behavior of waxy crude oil is important in order to adopt appropriate mitigative measures to forestall flow assurance problems associated with wax crystallization and deposition. Accurate predictive models are limited mainly by the sheer complexity of crude oil composition. Result of analysis of saturates, aromatics, resins and asphaltene content of crude oils (SARA) has been used as a simple tool to predict and interpret crude oil properties and behavior but has been found inadequate in predicting wax instability. In this paper, we report on the use of SARA analysis and paraffin distribution data to interpret the wax properties and flow behavior of Niger-Delta crude oils. The crude oil properties determined include wax content, asphaltene and resin content by gravimetry, pour point, wax appearance temperature by cross-polarized microscopy and paraffin carbon number distribution of whole oil and wax precipitate by GC-FID. Asphaltene and resin content were found to influence the oil pour point, while saturates content, paraffin carbon number of crystallizing waxes and wax content control its low-temperature flow properties.

Geochemical Characterization of Two Niger Delta Crude Oils and Their Mixtures I: Bulk Properties and Aliphatic Hydrocarbon Distributions

Two crude oils from Rivers and Delta States, Niger Delta Nigeria, samples A and F respectively, and their binary mixtures at different compositions, samples B, C, D, and E, were geochemically characterized using bulk properties and aliphatic hydrocarbon distributions. Results of density and API gravity, which classified samples A, B, C, D as light oils and samples E, F as medium oils, were observed to increase and decrease with increase in the composition of oil sample F respectively. The composition of the saturates, from 68.00 to 71.10%, suggest high maturity of the oil samples which did not show a relationship to the compositional mix of the two Niger Delta crude oils. Bimodal distribution of n-alkanes in samples A and B with a slight prominence of the short chain suggest marine source with significant terrestrial input, while the prominence of the long chain n-alkanes in sample F, which suggest a terrestrial source, progressively increased in samples C, D, and E. Pr/Ph ratios from 2.37 to 2.70 suggest source rocks deposited in an oxic environment. Ratios of Pr/nC17, from 0.94 to 1.20, and Ph/nC18, from 0.39 to 0.53, suggest shale source rocks with terrestrial higher plant input. From these results, the geochemical characteristics of the individual Niger Delta crude oils were exhibited by their binary mixtures. However, density, API gravity, n-alkane distribution, Pr/nC17 and Ph/nC18 ratios were expressed relative to the compositional mix of the two Niger Delta crude oils.

Awareness of Sexually Transmitted Infection and Cervical Cancer in Nigerian Female Adolescents [12F

INTRODUCTION: Cervical cancer is a sequel of Human Papillomavirus infection. Female adolescents in Nigeria are at high risk for future occurrence of this malignancy because of multiple concurrent sexual partners, and unprotected sex. High incomes and sophisticated lifestyles induced by the Niger Delta crude oil operations, youth unrest, peer group pressure, and substance abuse promote these sexually transmitted infections. Data should be collected from these adolescents to facilitate sexual behavioral change. METHODS: To determine the level of awareness of the relationship between sexually transmitted infection and cervical cancer. Information was collected from Two hundred and forty female adolescent secondary school students and undergraduates attending a holiday camp in Port Harcourt, South Nigeria. RESULTS: The mean age of the subjects was 15 years. Forty- eight (20%) subjects were under 13 years. 51% were aged 14 years to 16 years, and 29% were aged 17 years to 19 years. Forty-five per cent of the subjects were aware of cervical cancer but only 4% knew there was a relationship between unprotected sex and cervical cancer. The commonest sources of information were the media (50%), and hospitals (30%). None of the subjects was aware of the Human Papillomavirus vaccine. CONCLUSION: Adolescents are at increased risk for sexually transmitted infections, but have low levels of knowledge about their sequel. Promotion of sexual behavior attitudinal change facilitated by collection of data on sexuality will assist in reducing the incidence of cervical cancer in Nigeria.