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Bitumen is a complex mixture of organic molecules comprising mainly of hydrocarbons and it is use as a binder in constructions and in tarring of roads. This study was conducted to investigate some of the physical and mechanical properties of bitumen modified with natural rubber crumb (NRC) when cured and when left uncured. Five different blend ratios (2%, 6%, 10%, 14% and 18%) NRC by mass of the bitumen were used as modifiers. Penetration, softening point, Viscosity and Ductility tests were conducted on the ordinary bitumen and the blends. These basic property tests were used to explain the effect of natural rubber crumb and vulcanization on the binder (bitumen). Tests conducted gave a penetration value for ordinary bitumen 60/70 grade as 50.0mm and the value decreased to 32.5mm, 20.5mm, 19.8mm, 18.0mm and 17.4mm as the blend ratio increased from 2% to 18% respectively for the vulcanized mix and 46.0mm, 40.0mm, 36.0mm, 38.0mm and w41.0mm for the un-vulcanized blends as the blend ratio also increased from 25 to 18%. For softening point, 400C was enough to soften ordinary Bitumen but as the blend ratio increased from 2% to 18%, the temperature increased to 53.00C, 56.00C, 59.00C, 62.00C and 66.00C respectively for the vulcanized mix and for the uncured, 50.00C, 52.00C, 48.00C and 46.00C respectively. As the blending ratio increased, Viscosity also increased from 8seconds for the ordinary bitumen to 12sec, 23sec 50sec, 72sec and 84sec for the vulcanized mix and 10sec, 15sec, 27sec, 39sec and 48sec for the un-vulcanized mix respectively. Similarly, ductility also increased from 105cm for the ordinary bitumen to 124.0cm, 136.0cm, 151.0cm, 178.0cm and 200cm for the vulcanized blends and 115.0cm, 120.0cm, 129.0cm, 139.0cm and 152.0cm for the un-vulcanized mix respectively. These findings shows that NRC can be used to influence the chemical and physical properties of bitumen binder.

The utility of Nru clay for industrial application, which was taken from the Nsukka local government area in Enugu State, Nigeria, is assessed in this study for its physical and chemical properties. The clay was investigated chemically which showed SiO 2 51.2%, Al 2 O 3 18.3% as the predominant constituents while other metallic oxides such as Fe 2 O 3 5.3%, MgO 2.2%, Na 2 O 1.8%, CaO 1.4%, K 2 O 1.3% and MnO 0.7% were present in considerable proportion. The physical and mechanical analysis acknowledged a range in the linear shrinkage (4.17 - 6.25%), total shrinkage (7.8 - 10.2%), apparent porosity (36.92 – 26.58%), apparent density (2.59 - 2.37 g/cm3), bulk density (1.63 - 1.74 g/cm3), water absorption (22.64 – 15.33%) and modulus of rupture (6.70 – 9.15 kg/cm2) with an increase in firing temperature from 900°C to 1200°C. Nru clay can withstand heat without melting or deforming at temperature up to 1200 °C and exhibited reasonable plasticity with a modulus of plasticity of 1.42. We can infer from our investigation that Nru clay is a potential raw material for industries in the production of ceramics, high melting clays, fired bricks, and paints. Alternatively, the clays’ properties can be tailored to achieve superior physical and mechanical properties by enhancing them with additives. Therefore, it can be employed to cushion the exorbitant cost of importing clay minerals from other nations.

In this work, the adsorption of ciprofloxacin onto yam peel biosorbent was studied by batch method. The equilibrium isotherm analysis of the adsorption process was evaluated to provide insight into the removal mechanism. A decrease in the percentage removal (75.0 – 60.8%) and an increase in adsorption capacity (6.0 – 24.3 mg/g) with an increase in ciprofloxacin concentration from 20 – 100 mg/L was obtained. The isotherm was analyzed by the Langmuir, Temkin, Freundlich, and Scatchard models, and the best fit was obtained for the Freundlich model with a R2 of 0.9918. The separation factor in the range of 0.238 – 0.609 and the Freundlich adsorption intensity of 1.492 indicated a favorable adsorption of ciprofloxacin on yam peel. A monolayer adsorption capacity of 42.81 mg/g was obtained for yam peel which was higher than other efficient adsorbents. The Scatchard model gave a linear fit to the uptake data with R2 of 0.9653 and sum square error of 0.008. The isotherm analysis revealed complex adsorption involving multi mechanisms in the overall process. The results of this investigation showed that yam peel could be utilized as an efficient agricultural waste for the adsorption of ciprofloxacin from wastewater.

The physico-chemical and microbial examination of Ajali River in Ezeagu Local Government Area (LGA) of Enugu State, South-eastern Nigeria, were carried out to assess the characteristics of the water for potability. Water samples were collected from three sampling points, including the one close to the brewery effluent discharge into the river and two different points that were affected by non-point sources. Altogether, eighteen samples were collected for two years during the dry, early and late rainy seasons. The physico-chemical, as well as microbial analyses of the samples, were determined following the standard methods. Significant spatial and seasonal variations (p

The energy demand is on the global increase as the world economy is increasing steadily. Hence, the need to develop energy-saving technology with local raw materials and abundant waste materials becomes paramount. The mixtures of Enugu Iva-pottery clay, Nsu clay and PKS were evaluated to improve the quality of locally produced refractory for pyro-processing industries. The chemical and mineralogical composition of the PKS and the clay were determined. Eight recipes were made by varying PKS with quartz from 5 to 35% and produced by the wet pressing technique, then fired to 1200 °C and 1300°C respectively. The mechanical properties were determined by the Modulus of Rupture test, also, the bulk density, linear shrinkage, total shrinkage, apparent porosity, water absorption and thermal efficiency tests of the produced refractories were ascertained. The recipe with 15% PKS sintered well at 1300°C and gave the best optimum results of 1.76g/cm3 bulk density, 6.49% linear shrinkage, 21.384% apparent porosity, 20 cycles of spalling tests at 1300 °C. The results comply well with the standards of refractory properties. The PKS additives have shown significant improvement in the properties of the locally produced refractories and waste control; hence, can promote sustainable development of the local pyro-processing industry.

The efficiency of various benzimidazole derivatives as mild steel corrosion inhibitors in HCl and H2SO4 medium was evaluated using quantum chemical methods. The AM1 semi-empirical method and Density Functional Theory (DFT) at the B3LYP/6-31G* level were used. The orbital energies (EHOMO and ELUMO), Separation Energy (ELUMO-EHOMO), Dipole moment (µ), Log P, Polarizability, molecular volume, molecular weight, Hardness (η) and Softness (S) are the computed quantum chemical characteristics linked to inhibitory efficiency. There was a strong link between quantum chemical parameters and experimental inhibition efficiency. The findings revealed that the Inhibition Efficiency was linked to a number of quantum chemical factors. The 2-mercaptobenzimidazole derivative had a higher Inhibition Efficiency (IE) than the other benzimidazole derivatives, according to the results.

This investigation is on the treatment of a fibre-cement industry effluent (FCIE) using activated carbon (AC) adsorbent prepared by chemical activation (60% phosphoric acid) of Gossweilerodendron caesalpinoideae (GC) stem waste. The GCAC adsorbent was characterized by determination of the proximate and functional properties. The chemical groups, morphology and mineral phases of the GC stem waste and GCAC were studied by FTIR, SEM, and XRD methods, respectively. Kinetic and thermodynamic studies were carried out using total dissolved solids (TDS) as evaluating parameter. Effects of adsorbent dosage (5-40 g/L), contact time (0-60 min), and temperature (20-40 °C) on the effluent decontamination were investigated. Results from the characterized supernatant showed up to 97% removal of the contaminants using 40 g/L of GC adsorbent at effluent pH 7.4. The concentrations of TDS obtained by U-V spectrophotometric analysis were fitted to pseudo-first and pseudo-second order, Elovich and intraparticle kinetic models. The adsorption followed the pseudo-second order rate equation. Obtained free energy and enthalpy of adsorption values indicated non-spontaneous and endothermic adsorption. The study affirmed that the bioadsorbent, GCAC can be used for FCIE treatment.

More than 70% of oil-producing wells require some form of artificial lift to increase the flow of fluids from subsurface to the surface when a reservoir no longer has sufficient energy to produce at economic rates. This situation has been observed in the Niger Delta oil wells over the past years and has caused the abandonment of reservoirs with a significant volume of hydrocarbon. Data from two oil wells that could not flow naturally to the surface have been obtained from an oil company operating in the Niger Delta. The arm of this study is to optimize the production of two oil wells using an artificial lift system. To increase production and extend the life of these wells, artificial lift projects were considered. This was done with the aid of Integrated Production Modelling (IPM) tool in Petroleum Expert suite. Two wells were simulated using the obtained data, and their production performances were evaluated. The well’s production outputs were optimized using artificial lift systems, that is electric submersible pump (ESP), hydraulic pump (HP), and gas lift (GL). The results obtained showed that the ESP wells have the highest oil production rate compared to GL and HP respectively. An economic analysis was carried out using Net Present Value (NPV), Profitability Index (PI) and Internal Rate of Return (IRR). In terms of economic comparison, ESP is the most viable project with the highest NPV, PI and IRR Hence, the ESP technology proved to be the best technology for sustaining a high production rate, increasing revenue and proved to be economically viable in Niger Delta oil fields.

Fluid-flood and other improved oil recovery techniques are becoming prominent in global petroleum production because a large proportion of production is from mature oil fields. Although water flooding and gas injection are well established techniques in the industry, several of the screening criteria in literature are discipline which could sometimes be subjective. This work used experimental design techniques to develop proxy models for predicting oil recovery under water-flood and gas-flood conditions. The objective of the study is to develop a quantitative screening method that would allow for candidates to be evaluated and ranked for water flood or gas injection. The model was applied to some field cases and compared with published models and the well-known Welge Analysis method. The coefficient constants for the oil formation volume factor for water flooding and gas injection was 0.0139 and 0.0434 respectively. Similarly, the coefficient constants for water injection and gas injection for the generated proxy model was -2.34* 10-8 and -6.1 *10-5 respectively. The results show that the proxy models developed are quite robust and can be used for first pass screening of water and gas flood candidates.

The traditional method of using the coefficient of drag – Reynolds number relationship to predict cuttings settling velocity involves an implicit procedure that requires repeated, time-consuming and tedious iterations using Newtonian or mostly non-Newtonian correlations. Usually, these correlations are limited to certain fluid flow regimes. Besides, most of the explicit and direct cuttings settling velocity models that exist are based on the assumption that the cuttings are spherical particles. However, in the field, the cuttings are a mixture of various shapes and are hardly spherical, hence these models when applied to field conditions come off with huge errors. The objective of this work was to use a nature-inspired algorithm (artificial neural network - ANN) to develop a model for estimating cuttings settling velocity that would be robust and useful in the field that would take into account the shape of the cuttings. The data used for this work was obtained from research experiments in the literature. The model was then evaluated using four performance metrics namely: mean squared error (MSE), root mean square error (RMSE), sum of squares error (SSE) and goodness of fit (R2). It was found that the model's predictions obtained in this work agreed with experimental evidence. Furthermore, the developed model possesses the capacity to generalize across new input datasets and can be applied to particles of any shape, hence, defining the novelty of this research and bridging the gap between theory and practice. When compared with state-of-the-art models, the developed models show a high degree of robustness, as the ANN model performed reasonably well with an MSE of 7.5 × 10−4, an R2 of 0.978, RMSE of 0.0274 and SSE of 0.25. To generalize the results across new input datasets, the developed model was cross-validated with new data that was not part of the training process. It was found that the ANN model had an MSE value 0.00807, RMSE of 0.0898, MAE of 0.065, SSE of 2.74 and MAPE of 0.675%. To ensure the replicability of the ANN model, the weights and biases for the inputs, hidden and output layers are presented in this work unlike other artificial intelligence-based models in the literature. The range of application for the developed ANN model is 0.0001

Metals used in industries are exposed to several processes such as acid cleaning, pickling, and descaling, which leads to corrosion. A good measure of corrosion control has been achieved by reducin...

The instability of crude oil prices at the international market which results in revenue drop to oil and gas operators, the high cost of drilling multiple injection wells and installing gas reinjection systems in a bid to improve recovery of crude oil, have been of great concern to the Petroleum Industry. The Economic viability of Gas Reinjection for Enhanced Oil Recovery (EOR) (as against the gas flaring operation) was analyzed with 7 wells located onshore, in the Niger Delta region of Nigeria. The production history and reservoir data were gathered with which the cost analyses were conducted. Two scenarios involving seven production wells were evaluated. The first was converting two of the production wells to gas injection wells and producing from the remaining 5 production wells (IN2PROD5) and the other was injecting gas in two newly drilled injection wells and producing from the seven production wells (INJ2PROD7). It was shown that (INJ2PROD5) is a preferred option in extending the productive life of an otherwise depleted and uneconomic oilfield, having higher Net Present Value (NPV), Profitability Index (PI) and Internal Rate of Return (IRR) of -$53MM, 0.93 and 27.40% while the INJ2PROD7 had $161MM, 1.39 and 37.75% at discounted rate of 30% respectively. After subjecting the expected net revenues under various crude oil price sensitivity market vagaries, INJ2PROD5 will stand the test of time as it is less expensive and yielded a higher gross profit which is the major factor in any investment decision making.

Aims: The variations in production performances of the Black oil and compositional simulation models can be evaluated by simulating oil formation volume factor (Bo), gas formation volume factor (Bg), gas-oil ratio (Rs) and volatilized oil-gas ratio (Rv). The accuracy of these two models could be assessed. Methodology: To achieve this objective some basic parameters were keyed into matrix laboratory (MATLAB) using the symbolic mathematical toolbox to obtain accurate Pressure Volume Temperature (PVT) properties which were used in a production and systems analysis software to generate the production performance and hydrocarbon recovery estimation. Standard black oil PVT properties for a gas condensate reservoir was simulated by performing a series of flash calculations based on compositional modeling of the gas condensate fluid at the prescribed conditions through a constant volume depletion (CVD) path. These series of calculations will be carried out using the symbolic math toolbox. PVT property values obtained from both compositional modeling and black oil PVT prediction algorithm are incorporated to determine the production performance of each method for comparison. Results: The absolute open flow for the black oil PVT algorithm and the compositional model for the Rs value of 500 SCF/STB and Rs value of 720SCF/STB were 130,461 stb/d and 146,028 stb/d respectively showing a 10.66% incremental flow rate. Conclusion: In analyzing PVT properties for complex systems such as gas condensate reservoirs, the use of compositional modeling should be practiced. This will ensure accurate prediction of the reservoir fluid properties.

The pollution of water bodies with ciprofloxacin (CF) and other antibiotics has resulted in undesirable characteristics, such as color, odor and microbial resistance in environmental waters. Using agricultural waste as biosorbents for the removal of antibiotics from wastewater is a promising treatment approach. This research was based on the treatment of CF-polluted water by utilizing acid-modified Dialium guineense (tamarind) seed waste (HA-DGS), prepared by hydrochloric acid treatment of Dialium guineense seed (DGS). HA-DGS exhibited a maximum CF uptake of 125 mg/g, which was higher than most adsorbents reported in the literature. The DGS and HA-DGS were characterized by the FTIR, SEM, EDX, TGA and BET analyses. The acid modification was optimized by the application of response surface methodology using central composite design. Batch methodology showed that HA-DGS had higher CF uptake than DGS at variations of pH, temperature, contact time, adsorbent dosage and CF concentration. The Freundlich isotherm with R2 > 0.9795 was more applicable to both adsorbents, while DGS conformed to the pseudo-second-order kinetic (R2 > 0.9939) and HA-DGS (R2 > 0.9085), to the pseudo-first-order kinetics. Thermodynamics showed a physical and exothermic uptake of CF on the adsorbents. HA-DGS exhibited a maximum CF uptake of 125 mg/g, which was higher than most adsorbents reported in the literature. Quantum chemical parameters and condensed Fukui functions revealed efficient interaction between CF molecules and the prepared materials. Over 60% desorption of CF was obtained from the CF-loaded adsorbents using water and HCl solution. The results of this research showed HA-DGS as an efficient, low-cost, waste material that can be optimally valorized in the treatment of wastewater contaminated with CF.

The elimination of residual free water and Basic Sediments (BS&W) after field demulsification process and characterization is being investigated with a diluent, to enhance field treatment for quality assurance and crude oil custody transfer. The American Standard for Testing Materials (ASTM) D 4007 is used as separation technique for three field emulsion samples from two Niger Delta basin oil facilities. After an initial bottle test, free water content in crude oil samples on arrival were 0.65%, 0.70% and 0.55% for samples A, B and C respectively. Tests and analysis were carried out at room temperature of 28°C and a water-bath temperature at 60°C. Maximum water separation efficiency of 91% was achieved at diluent and emulsion concentration ratio of 1:9 in first 60 minutes to 720 minutes. BS&W reduced from an average of 0.6% to 0.25%. Emulsion separation index (ESI) provided emulsion stability measurement of respective samples with a contrast between static-laboratory and field-dynamic conditions. From the study, sample B has API of 39 and ESI=40 while recording greater separation than in A and C crude oil samples. Hence, separation efficiency increased with the amount of xylene added and free water percentages reduced in top dry oil with significant changes in BS&W.

This work evaluated the use of Dialium guineense seed waste (DGS) and its sodium hydroxide modified form (NH-DGS) as biosorbent for ciprofloxacin (CPF) from synthetic solution as well as the desorp...

Carbon adsorbents derived from biomass (agricultural and household residues) have been widely used in the sequestration of hazardous substances from the environment due to their distinctive qualities of large internal surface area, mechanical integrity, and regeneration. The need for carbon adsorbents for sequestration of dyes, heavy metals, and crude oil components has increased because of environmental concerns. This has led to studies of carbon adsorbents derived from agricultural and household biomass residues. These adsorbents have been used to remove pollutants. Although numerous reviews have been published before, analogy of results obtained using different adsorbents is hard due to dissimilarities in research data. Against this backdrop, the purpose of the research survey was to review the contemporary publications regarding the production of activated carbon from biomass sources highlighting specifically its utilization in removing toxic wastes from water solution such as oil spill, dyes, and sundry hazardous substances. Also the work focuses on the methods for the restoration of the spent adsorbents and their end use.

In this paper, an artificial neural network model was developed to predict the downhole density of oil-based muds under high-temperature, high-pressure conditions. Six performance metrics, namely goodness of fit (R2), mean square error (MSE), mean absolute error (MAE), mean absolute percentage error (MAPE), sum of squares error (SSE) and root mean square error (RMSE), were used to assess the performance of the developed model. From the results, the model had an overall MSE of 0.000477 with an MAE of 0.017 and an R2 of 0.9999, MAPE of 0.127, RMSE of 0.022 and SSE of 0.056. All the model predictions were in excellent agreement with the measured results. Consequently, in assessing the generalization capability of the developed model for the oil-based mud, a new set of data that was not part of the training process of the model comprising 34 data points was used. In this regard, the model was able to predict 99% of the unfamiliar data with an MSE of 0.0159, MAE of 0.101, RMSE of 0.126, SSE of 0.54 and a MAPE of 0.7. In comparison with existing models, the ANN model developed in this study performed better. The sensitivity analysis performed shows that the initial mud density has the greatest impact on the final mud density downhole. This unique modelling technique and the model it evolved represents a huge step in the trajectory of achieving full automation of downhole mud density estimation. Furthermore, this method eliminates the need for surface measurement equipment, while at the same time, representing more accurately the downhole mud density at any given pressure and temperature.

Pressure traverse in multiphase flow differs from single phase flow due to the differential flow rates of the different phases. Correlations developed to predict multiphase flow pressure traverse are mostly for vertical wells but Beggs and Brill model is one of the few models that is used for inclined pipes. The work seeks to show the improvement in the modification of the model. This project is based on studies carried out on multiphase fluid flow in pipes of any inclination using the Beggs and Brill flow model as the focus. Two cases were considered, the liquid holdup correction and Gas Liquid Ratio (GLR) variations in which the Beggs and Brill and Beggs and Brill Traverse models were compared. Due to the empirical nature of the Beggs and Brill model, pressure gradient predictions are far from accurate when compared with measured data in the field. This project seeks to reduce the error margin between predicted pressure gradient values and measured data. It was observed that for the same reservoir, fluid, and pipe properties, the Beggs and Brill Traverse Model is a better prediction tool than the Beggs and Brill model. Prediction errors were seen to increase with increase in length for GLR above 400 scf/stb while they were more accurate for pipes between 12,000 and 17,000 ft and pressures between 3,000 and 4,500 psi. However, the Beggs and Brill Traverse Model, is limited by the choice of correlations used in the computation of fluid properties. It is necessary to predict pressure drop in vertical multiphase flow in order to effectively design tubing and optimum production strategies.

Few reports exist on the use of natural inorganic sorbents such as clays compared to organic biomass materials for crude oil sorption . Also, the mechanistic kinetic, isotherm and thermodynamics have seldom been discussed in the few clay oil sorption studies available. This work evaluated the use of Natural Clay (NC) for removal of crude oil from solution. The sorbent was characterized by the Fourier transform infrared, scanning electron microscope , X-ray diffraction, X-ray fluorescence and Brunauer-Emmett-Teller surface area analyzer. The chemical oxide composition revealed SiO 2 (53.1%) and Al2O3 (19.8%) as major components of NC and cation exchange capacity of 76.1 mEq/100 g. The Langmuir model presented the best fit with higher R2 of 0.981 and lower Sum square error (SSE) of 0.21 compared to the Freundlich and Tempkin isotherm. The pseudo-first order model was found to be applicable compared to the pseudo-second order kinetic analysis, with intra-particle diffusion mechanism involved in the removal process. Thermodynamics revealed a spontaneous, endothermic and physical sorption of crude oil on NC. The sorption capacity of NC for crude oil was found to be higher than most sorbents reported in literature. NC showed good regeneration and reusability for crude oil removal using n hexane after three cycles of sorption-desorption experiment The study indicated enormous potentials of NC as low cost sorbent for oil spill treatment.

The study investigates the sorption of cadmium (Cd) and lead (Pb) by Nsukka urban soils, a Nigeria soil classified as an ultisol soil of tropics. Laboratory batch technique was utilized to investigate the effect of pH, temperature, contact time, and concentration on the adsorption process. Results showed that adsorption efficiency of the soils for Cd2+ and Pb2+ increased with increase in pH, temperature, and contact time but decreased with increase in concentration. The data from adsorption study was fitted to the Langmuir, Freundlich and Temkin adsorption isotherms, and results revealed that Langmuir isotherm fitted most satisfactorily. On the basis of the obtained maximum adsorption capacity (qmax) from the Langmuir model, the affinity of Cd and Pb for the studied soil was Pb2+ > Cd2+. Pseudo-second order (r2 ≥ 0.995-0.999) best described the kinetics of the sorption process for the metal ions in the soil.

The adsorptive removal of total dissolved solids by activated coal using response surface methodology was investigated. A four-variable central composite experimental design was applied to correlate the adsorption variables (effluent pH, adsorbent dosage, contact time, and adsorption temperature). The adsorption variables were optimized based on the removal of total dissolved solids from fibre cement industry effluent. Three-dimensional surface plots were generated to estimate the effect of the combinations of the independent variables on the adsorption efficiency. The results of the model validation gave experimental yield 96.2%, predicted yield 96.5% obtained at effluent pH 6.27, adsorbent dosage 27.60 mg L−1, contact time 48.00 min, and adsorption temperature of 31.00 °C. The good agreement found between observed and predicted values supports the suitability of the applied model to predict the adsorption treatment.

Codiaeum variegatum stem powder (CVSP) was used as a low cost, readily available and biodegradable sorbent for decontamination of crude oil from aqueous solution. CVSP was characterized by ...

In this paper, a comprehensive review of experimental, numerical and artificial intelligence studies on the subject of cuttings settling velocity in drilling muds made by researchers over the last seven decades is brought to the fore. In this respect, 91 experimental, 13 numerical simulations and 7 artificial intelligence researches were isolated, reviewed, tabulated and discussed. A comparison of the three methods and the challenges facing each of these methods were also reviewed. The major outcomes of this review include: (1) the unanimity among experimental researchers that mud rheology, particle size and shape and wall effect are major parameters affecting the settling velocity of cuttings in wellbores; (2) the prevalence of cuttings settling velocity experiments done with the mud in static conditions and the wellbore in the vertical configuration; (3) the extensive use of rigid particles of spherical shape to represent drill cuttings due to their usefulness in experimental visualization, particle tracking, and numerical implementation; (4) the existence of an artificial intelligence technique - multi-gene genetic programming (MGGP) which can provide an explicit equation that can help in predicting settling velocity; (5) the limited number of experimental studies factoring in the effect of pipe rotation and well inclination effects on the settling velocity of cuttings and (6) the most applied numerical method for determining settling velocity is the finite element method. Despite these facts, there is need to perform more experiments with real drill cuttings and factor in the effects of conditions such as drillstring rotation and well inclination and use data emanating therefrom to develop explicit models that would include the effects of these. It should be noted however, that the aim of this paper is not to create an encyclopaedia of particle settling velocity research, but to provide to the researcher with a basic, theoretical, experimental and numerical overview of what has so far been achieved in the area of cuttings settling velocity in drilling muds.

Our definition of ‘The Big Data’ is the ability of having all the data set at the point of decision-making. Several documented research shows that less than 5% of all the data acquired in the oil and gas industry are actually utilised. Despite these challenges most operating assets, still keep acquiring more data and creating data-load that are never utilised or put into use. This paper aims to demonstrate the reason(s) why we have this data-load and instigate a solution path in managing this challenge for value realisation. Data is a corporate asset in any organisation but the default ‘silo’ work culture in most operating asset makes it difficult to get the relevant insight from these data. Organisation must be deliberate in creating the right data architecture from the data process domain through into the distributed control system, into the data historian, then within the data platform and the visualization realm and finally into the workflow domain. It is at the workflow domain that we get the ‘game-changer’ otherwise called value. This is the differentiating factor in delivering the ‘Big Data’ into the space of benefit realisation. This was what was achieved in a field in Niger Delta and has been shared compared to global best practice. The documented result from this case study showed that any data architecture should be framed to address asset business need, right from the data process domain function through to the data historian into the workflow level where the business objective is addressed. Data must be application-centric accounting for scalability, accessibility, security and business performance. Assets need to be clear on why they are acquiring data and not just continuous acquisition of more data with the resultant effect of data-load without answering the question; what next after data acquisition? This paper provides the answer of what next after data acquisition and serves as a quick reference tool for similar challenge elsewhere, not limited to the oil and gas industry.

In oil and gas exploration and production, it is essential to have a reliable estimation of Oil initially in Place (OIIP). Reliable reserve estimation depends on the petro physical data used in the volumetric method of estimating OIIP. This estimation is done at the primary phase of exploration where production data are not yet available. The effects of petrophysical data and their sensitivity on OIIP were determined. Average petrophysical data were obtained from reservoir X, Y and Z within the Niger delta and analyzed by running a Monte Carlo simulation using computer-based application such as MS Excel and MS Minitab (Design of Experiments (DOE). 10,000 random data sets were generated for each petrophysical property from the average field data obtained from Reservoirs X, Y and Z in the Niger Delta region. The simulation results were further analyzed using sensitivity indices and Tornado plots. For reservoir X, the percentage effect of porosity, oil saturation, pay thickness, drainage area, oil formation volume factor (oil FVF) on OIIP were 97, 95, 90, 70, and 5 respectively. For Reservoir Y, the percentage effect of porosity, oil saturation, pay thickness, drainage area, and oil FVF on OIIP were 95, 89, 83, 58, and 4 respectively. For Reservoir Z, the percentage effect of porosity, oil saturation, pay thickness, drainage area, and oil FVF on OIIP were 95, 89, 80, 75, and 4 respectively. Results from the various analysis carried out proved that porosity had the highest and positive effect on OIIP, followed by oil saturation and pay thickness, oil formation factor has the least significant effect and in some cases negative effect on estimated OIIP. In the long run, these understanding will help the reservoir engineer identify the sensitivity of each parameter when carrying out volumetric estimation of OIIP and also the need for sourcing quality reservoir and petrophysical data using different available cost-effective and efficient methods.

Efficient Project Management in Digital Oilfields (DOF) space usually focus in addressing the asset business challenges through clearly defined business objectives for the project implementation. One of the key reason why such digital oilfields project implementation fails is because most operating asset use the ‘conventional project management approach’ in dealing with digital oilfields implementation. The ‘Conventional Project Management’ approach rest the entire responsibility of managing the project on the Project Manager who is normally NOT a member of the business or asset. This Project Manager usually abandons this role of managing the implementation after ‘Go Live’ or on ‘completion’ of the project. The objective of this presentation is to identify the reasons why the ‘conventional project management framework’ fails and proffer a field-tested project management approach that ensures seamless embedment of the Digital Oilfields Transformation solutions. A field-tested approach is demonstrated through research work in a field where a Business Opportunity Manager (BOM) who is a member of the business (not from the project team) who actually anchored the implementation of digital oilfields solutions in an asset in Gulf of Guinea. The Business Opportunity Manager actually interfaces between the business and the project team right from inception of the project through into the handover of the project to the business thereby ensuring seamless embedment and sustainability of the realised solutions for continuous business improvement. Digital Oilfields (DOF) Transformation is a continuous business improvement initiative in project management. The results show significant business benefits from this option of using the Business Opportunity Manager from the business in delivering the solutions rather than the conventional project manager that takes overall management of the project and leaves on ‘completion’ of the project implementation. The gains or value proposition from the DOF implementation are sustained and continuously improved with solid embedment process. This result will serve as reference tool and assist Digital Transformation experts build a sustainable framework in similar project implementation and management, globally.

In the exploration for hydrocarbons, a successful drilling operation to the desired depth hinges on the effective performance of the formulated drilling fluid. Apart from carrying drill cuttings to the surface, another major function of the fluid is to seal off the walls of the wellbore to prevent fluids from coming into and out of the wellbore while drilling a well. Numerous commercial fluid loss additives: carboxymethyl cellulose (CMC), polyanionic cellulose (PAC), among others have been in existence with their drawbacks and effect on the total drilling cost. This study evaluates the use of locally sourced materials: Detarium microcarpum, Brachystegia eurycoma and rice husk, as fluid loss control additive in the water-based drilling fluid. The materials were prepared, ground and sieved to 125 microns. Four sets of water-based drilling muds were formulated using the local materials and CMC as fluid loss control additives. The mud formulation was based on the American Petroleum Institute (API) standard of 25g bentonite to 350mL of water. Also, the filtration test of the formulated muds was performed using API recommended practice for static filtration test at low temperature - low pressure (LTLP) condition. The results obtained showed that Detarium microcarpum and rice husk fluid loss volume and filter cake thickness were comparable with that of CMC from additive content of 10g, while Brachystegia eurycoma was comparable from additive content of 15g. Furthermore, the composite additive results indicated that Detarium microcarpum-rice husk at 95% Detarium microcarpum-5% rice husk performed better than Brachystegia eurycoma-rice husk of the same combination. Additionally, the fluid loss volume and filter cake thickness of Detarium microcarpum-rice husk additive were comparable with CMC from 10g content. Also, the results revealed that the fluid loss volume and filter cake thickness obtained from the locally sourced materials were within API specification for fluid loss control agents. The mud filter cake characteristics exhibited by these materials depicted that they have slippery, smooth and soft mud cakes; thus, the characteristics of a good mud cake that will prevent differential pipe sticking., Chemical engineering; Locally sourced materials; Fluid loss control additive; Fluid loss volume; Filter cake thickness; Mud cake characteristics.

This work evaluated the use of

The adsorption capacities of montmorillonite for heavy metals from effluents have been improved by acid and alkaline treatments. However, the use of these chemicals is expensive, noxious to the env...

For an oil well to be said to have been successfully and conclusively drilled, the drilling fluid lies at the heart of the solution. Therefore, the guarantee to solving issues in oil well drilling is to contrive an optimal drilling fluid. However, there is usually a complex interplay of factors involved during drilling fluid formulation, property determination, its performance in the well and its relationship with other wellbore drilling parameters. This is so because drilling muds exhibit time dependent properties. This time dependency is the direct product of the synergy among the various active additives that make up the mud and the characteristic of each additive especially at downhole conditions where the effects of temperature and pressure are well pronounced. These additives are more often than not diverse in size, chemical activity, density and surface energy. Deriving knowledge from the data from these parameters in order to develop a functional relationship between them is a challenging task requiring advanced modelling techniques as well as human intuition and experience. The dependence on human intuition and on the experiential knowledge of professional mud engineers lays bare the shortcomings of traditional mud design techniques. Artificial intelligence techniques have been shown to alleviate this challenge. Exploiting the abundant literature on the various applications of artificial intelligence in oil and gas operations, several works that show how and what artificial intelligence techniques are used in the drilling fluid industry, and what have been achieved due to their use have been selected. In this paper, a review of existing artificial intelligence techniques and their applications in drilling fluid engineering is given. This paper also dug up and analyzed the strengths and pitfalls of each artificial intelligence technique. The examination of the strengths and deficiencies was done using the following virtues as the basic criteria: robustness against noise, self-organization, generalization ability, data volume requirements and the convergence speed. The artificial intelligence techniques presented in this paper include: artificial neural networks (ANNs), fuzzy logic, support vector machines (SVM), hybrid intelligent systems (HIS), genetic algorithms (GA), case based reasoning (CBR) and particle swarm algorithm (PSA). An overview of the applications of classical artificial intelligence in drilling fluid engineering is also presented. From the review, it was gathered that the ANN technique is the most widely applied in drilling fluid engineering accounting for over 54% of the papers reviewed; while lost circulation problem was the most predicted well problem related to drilling fluids accounting for over 17% of the mud problems predicted. It was also observed that a blend of AI techniques performed better than when each one of the AI techniques was used singly. Finally, judging the AI techniques on the criteria mentioned above, ANN was found to meet all the listed criteria except for its slow speed of convergence while ANN, GA, SVM and fuzzy logic were all found to be robust against noise.

The need for converting waste to wealth triggered the zeal to undertake this work. This study focused on cellulosic agro waste materials that have the potential to control filtration loss in drilling muds. There was a wide spectrum from which to choose from – from the obvious to the complex. The choice of these materials was based on the characterization of each of them from published literature but was narrowed down to the ones available in Nigeria. From the review, it was observed that a good number of researchers have been diligently studying the use of agro-waste materials as filter loss control additives in drilling muds. The inclination of most of the research studies have been towards assessing the potential of using the cellulosic agro waste materials as fluid loss control additives and then comparing their rheological and filter loss characteristics with the conventional fluid loss control additives. The available studies by various researchers on this subject have been compiled from 1997 to 2017 and the findings of each researcher is highlighted. A summary of the findings indicate that the agro waste materials were historically used as lost circulation materials, and that a mixture of two or more agro waste materials prevents lost circulation better than when used alone. However, this review further show that agro waste materials are ubiquitous and inexpensive and could equally serve as filter loss control agents in drilling muds. Thus, their utilization as filter loss control agents in drilling muds help reduce environmental pollution and ultimately reduce drilling fluid costs. From an economic perspective, this work indicates that all the agro waste materials were cost effective even after processing compared to the conventional fluid loss control materials such as carboxymethyl cellulose and polyanionic cellulose. In this respect, saw dust and corn cob were found to be the cheapest and most expensive agro waste materials respectively. This work also highlighted some gaps in the literature which should be filled. These gaps include but are not limited to: microscopic structure analysis and filter cake properties description of the muds formulated with agro waste materials.

As the demand for hydrocarbons increases, the search frontiers for petroleum and natural gas deposits keep being pushed towards unconventional terrains. An example of an unconventional terrain where oil and gas deposits can be found is the high temperature and high pressure (HTHP) environment. While HTHP wells can hold a wealth of resources, they are difficult and expensive to complete. One area of difficulty is in optimizing the rheology of muds used for drilling wells in these environments. As a result, a plethora of laboratory, field and modelling studies have been conducted on mud rheology under HTHP conditions. Despite the huge number of studies on this subject, bibliometric analysis indicates that in the last five decades, there is no comprehensive, up-to-date review on mud rheology under HTHP conditions. This work is therefore an attempt to curate the laboratory, field and modelling studies on mud rheology in HTHP conditions with a view to highlighting recent advances on the subject and identifying grey areas where more studies should be directed. The contributions of the current study for which novelty is claimed include: a comprehensive curation and critique of HTHP mud rheological models, laboratory studies, HTHP mud cost analysis and a detailing of learnings from specific field experiences on HTHP mud rheology. A conscious effort was made to present the review in a straightforward manner with enough theoretical background so that readers in and outside of the drilling community can benefit. Although the authors have striven for completeness, it is essentially an impracticable undertaking to be exhaustive. Results from the review indicate that while the relationship between mud rheology and temperature and pressure in HTHP wells remains complex, additives with high thermal and rheological stability are available and can be used in HTHP drilling. The real essence of this work is not to create an encyclopaedia of mud rheology experiments but to facilitate the understanding of the behaviour of various mud types under HTHP conditions. Better still, it could serve either as a useful reference for the academic community or as an added preparatory guide and checklist to wellbore drillers planning to drill in HTHP environments.

Drilling mud is a mixture of base fluid and other materials combined in specified amounts for the purpose of cleaning a drilled well. Some of its functions during drilling include but are not limited to the following: cuttings transport, cooling and lubrication of drillstring, consolidating wellbore walls and controlling formation pressure. These functions are executed concurrently. In order to improve the drilling process, a robust mud rheological model is needed to capture the dynamics of the mud flow. This work synthesises an appreciable amount of studies on the modelling of oil well drilling mud rheological properties. While a substantial number of models have impacted the literature, to the best of our knowledge, a critical appraisal of these models has not. Furthermore, there is little or no literature review of the knowledge gained from these models to date. A lot can be gleaned by concentrating on the former; principal of which would be relevant for deepening knowledge on the subject. Hence, an attempt has been made to orient the contents of this review towards critiquing the extant models and charting a new course for future studies. This is what makes this study novel and serves as its major contribution. To enable an understanding of the subject, some consideration of theoretical information has been put in place. The general ‘filter’ for inclusion of models in the current review has been that the model should (1) have been published in peer-reviewed journal papers or conference proceedings and (2) the model is specifically for predicting drilling mud rheological properties (plastic and apparent viscosity, yield point and gel strength) and not crude oil or oil well cement rheology. The review highlights what algorithms were used, their relative successes, limitations, performance as well as input parameters which aided in estimating mud rheological properties. For convenience and ease of reference, these models are organised chronologically in simple tables. Results of the bibliometric survey show that though there are numerous modelling approaches in the literature, artificial neural network was the most popular algorithm among researchers. It is also noticed that fuzzy logic theories and a fusion of traditional sensors and machine learning algorithms are recently gaining traction in their use. Furthermore, it is also observed that while yield point, plastic and apparent viscosity are widely modelled, little attention is given to the gel strength. This review constitutes the first critical compilation on a broad range of models applied to estimating mud rheological properties with the aim of supplying vital elements necessary for an improved understanding of the concept of mud rheology. Despite the authors’ effort at being comprehensive, the list of models in this work is far from exhaustive. Nonetheless, the consolation is that it has captured the majority of mud rheological properties models in the literature. The information contained in this review is intended to be of assistance to researchers and the drilling community in the making of technically correct and cost-effective decisions on mud rheology.

N -(2-chloroethyl)morpholine-4-carboxamide (NCMC), N -(2-chloroethyl)tiomorpholine-4-carboxamide (NCTC) and N , N -bis(2-chloroethyl)piperazine-1,4-dicarboxamide (NCPD) were studied as corrosion inhibitors for mild steel using atomic absorption spectroscopy (AAS) and gravimetry and thermometry. Results obtained from the three techniques are similar and reveal that the compounds inhibit mild steel corrosion. The inhibition efficiencies increased from 35.6% to 74.9% (NCMC), 44.5% to 82.4% (NCPD) and 52.6% to 90.1% (NCTC) at 30 °C when the inhibitor concentrations increased from 10 μM to 50 μM. The maximum inhibition efficiency values (at 50 μM) decreased to 46.6%, 58.1% and 61.2% for NCMC, NCPD and NCTC respectively, when the temperature was raised to 50 °C. The decrease in inhibition efficiency with increase in temperature suggested predominant physisorption mechanism in metal/inhibitor interactions. The formation of protective films of NCMC, NCPD and NCTC molecules on mild steel surface were confirmed by FTIR and XRD. The order of inhibitive strengths of the molecules is NCTC > NCPD > NCMC. Quantum chemical calculations revealed the prospective sites through which the molecules can interact with mild steel surface and some quantum chemically derived parameters were used to corroborate experimental.

Removal of arsenic(III) from aqueous solution has been studied using activated carbon produced from Dialium guineense seed shell by impregnation of carbonized sample with zinc chloride and thermal activation. The zinc chloride activated sample was selected because it produced the highest iodine number, mg/g (962.52) compared to the raw sample (601.57), phosphoric acid and nitric acid impregnated samples (802.10, 868.95). Proximate analysis of raw D. guineense seed shell revealed low ash content of 1.70% and moderate fixed carbon of 32.97%. The prepared adsorbent was characterized using Brunaeur–Emmett–Teller surface area, SEM and FTIR analyses. The surface area of the zinc chloride activated adsorbent was 533.94 m2/g and its micropore volume 0.475 cm3/g, with a porous structure that is well organized. Batch adsorption experiments were done by changing the following parameters: adsorbent dose, pH, contact time, initial metal ion concentration and temperature. Adsorption increased as each parameter was varied but decreased with increase in initial arsenic(III) concentration. The Freundlich model presented better fit with R2 of 0.998 compared to the Freundlich isotherm (0.991) and Tempkin isotherm (0.984). The positive value of ∆H° 51.68 kJ/mol showed the endothermic nature of adsorption. The study demonstrated the potential of D. guineense seed shell as low cost adsorbent for removing arsenic(III) from polluted water.

The ‘JEB’ oilfield has been in operation since 1992 with 24 oil producing Wells, 8 water injection Wells and no gas injection. From inception, the field was producing at the rate of 27 MSTB/D. The gas produced was 34,333.7 SCF/D which was being flared but later supplied to the Nigeria Liquefied Natural Gas (NLNG) for export. The field had very weak aquifer support and therefore had been water-flooded from early days of its production. With high water cut, it was necessary to find ways of reducing water production and increasing oil production. The study involved field data gathering, history matching of the field data and prediction of future production. Production rates from the different production schemes were simulated for fourteen years. The cumulative oil production of gas injection, water alternating gas (WAG) injection and gas alternating water (GAW) injection schemes were 4.28 MMMSTB, 3.29 MMMSTB and 3.15 MMMSTB respectively representing an incremental recovery of 38%, 6%, and 1%. The cumulative water production of gas injection, WAG injection and GAW injection were 2.65 MMMSTB, 6.52 MMMSTB and 6.90 MMMSTB respectively, which represent 64%, 10% and 5% reduction in produced water. The economic analysis showed gas injection as the best alternative injection scheme for the field with internal rate of return (IRR) of 19.26 %, while the IRR of WAG and GAW injection schemes were 12.09 % and 11.22 % respectively. Also, at 15% discount rate, the gas injection scheme had the best result with a Profitability Index (PI) greater than 1, a positive Net Present Value (NPV) while all other injection schemes had negative NPV and PI was less than one. The possibility of changing a field from water injection to gas injection has been explored, hence, before embarking on any enhanced oil recovery scheme, other alternatives should be evaluated.

When drilling with water based muds (WBM), significant fluid loss volumes from the mud into the formation can have adverse effects not just on the mud and its properties but also on the stability of the wellbore. Prevention of mud filter loss is one way of assessing the performance of a drilling mud. However, evaluation of the effectiveness or otherwise of a fluid loss control additive can be made by characterizing the mud cake formed. Interestingly, the mud cake characterization is one area that has been somewhat neglected in drilling fluid formulation with agro waste materials. Two cellulosic materials - rice husk and saw dust were chosen for the experimental study. The specie of the rice husk used was the African rice (Oryza glaberrima) while the dust from the saw milling of Oxystigma manni was utilized for this study. To ensure result acceptability, the rice husk and saw dust were ground and the resulting products were sieved to 1.25 × 10−4 m. The filtration characteristics of the formulated mud samples were tested using the American Petroleum Institute (API) filter press and in accordance to the API recommended practice for field testing WBMs. From the filter loss tests, it was observed that the ground rice husk prevented filter loss by an average of 77% compared to ground saw dust filtration control of 63%. In addition, it was observed that at higher concentrations, ground saw dust and rice husk prevented fluid loss to the minimum acceptable API standard. For the filter cake thickness measured in millimetres, ground rice husk exhibited thicker mud cakes when compared with the saw dust by an average amount of 14%. For the mud cake characteristics, the rice husk mud exhibited smooth and slippery cakes while the saw dust mud exhibited rough texture, sticky and firm cakes.

As the rate of obesity and the incidence of diabetes mellitus have been increasing, diabetic neuropathy has become the most common cause of peripheral neuropathy in developed countries. In addition, a variety of pathogenetically heterogeneous disorders can lead to impairment of the peripheral nervous system including amyloidosis, vitamin deficiencies, uremia and lipid disorders, alcohol abuse, autoimmune and infectious diseases as well as exposure to environmental toxins. We have noted that a combination of these disorders may aggravate the manifestations of peripheral diabetic neuropathy, an effect, which is most pronounced when metabolic and non-metabolic pathologies lead to cumulative damage. Current treatment options are limited and generally have unsatisfactory results in most patients. Therapeutic apheresis (INUSpherese®) allows the removal of metabolic, inflammatory, immunologic and environmental contributors to the disease process and may be an effective treatment option. We reviewed the developments in therapeutic apheresis for metabolic and non-metabolic peripheral neuropathy, including the current literature as well as data from our university diabetes center. © 2019 American Institute of Physics Inc.. All rights reserved.

Biomethanation potentials of pig dung co-digested with pineapple peels were investigated. Various blends of pig dung with pineapple peels were charged respectively into 50 kg prototype digesters labeled A to C. Digesters D and E were charged with only pineapple peels and pig dung respectively. Proximate and physico-chemical analyses were determined on the slurry using conventional methods. The wastes were subjected to anaerobic digestion for 35 days at mesophilic temperature range of 25 to 37°C. Relative humidity, ambient temperature, pH, slurry temperature and volume of gas were monitored and recorded on daily basis. Biogas yield increased progressively with higher pig dung blend. Onset of gas flammability was observed on the 5th day for blends of pig dung and pineapple peels, as well as for pineapple peels alone while for pig dung alone, it was observed on the 6th day. This was as a result of lower nitrogen contents of pineapple peels blends compared with that of pig dungs alone, a factor which favours early onset of flammability. Biogas generated from the mixture ranged from 65- 71% CH4, 28 -34% CO2, and traces of hydrogen sulphide and carbon (II) oxide. The biogas was subsequently stored in a gas cylinder using modified pressure system. This study is aimed at converting wastes such as pig dung and pineapple peels to useful energy and storing the gas produced in cylinders for easy accessibility.

The main objective of this paper is to use experimental measurements of downhole pressure, temperature and initial mud density to predict downhole density using multigene genetic programming. From the results, the mean square error for the WBM density model was 0.0012, with a mean absolute error of 0.0246 and the square of correlation coefficient (R2) was 0.9998; while for the OBM, the MSE was 0.000359 with MAE of 0.01436 and R2 of 0.99995. In assessing the OBM model's generalization capability, the model had an MSE of 0.031, MAE of 0.138 and mean absolute percentage error (MAPE) of 0.95%.

Additives to drilling fluids and oil well cements play a significant role during wellbore drilling operations. These additives (such as carboxymethyl cellulose and starch) are often expensive and most times degrade at high temperature conditions. Although seashells (usually considered waste materials) have been utilized for various purposes in drilling muds as weighting agents and lost circulation materials, however, to the best of our knowledge, there is no research conducted yet to test their feasibility and performance as retarders or accelerators in oil well cements. In addition, no study has compared the filter loss capabilities of these seashells as drilling mud additives. Filling this gap is what makes this work novel and is the major contribution of this work to the extant literature on this subject. The specific objective of this work is to bring to light how useful seashells could be as a drilling mud and oil well cement additive from an experimental standpoint. To this end, the capability of the pulverized and calcined shells of egg, snail, oyster and periwinkle as mud filter loss control agents and as oil well cement additives were evaluated. Thirteen water based mud samples and one oil well cement sample were formulated with the shells as additives. The basic tests run on the formulated mud and cement samples were the filter loss test (using the American Petroleum Institute filter press) and cement setting time tests (using the Vicat’s apparatus) for the mud and cement respectively. The conventional filter loss control material - carboxymethyl cellulose (CMC) was used as the control. Results from the filtration tests showed that the filter loss capability of the shells decreased from egg shell to snail shell to periwinkle shell. With respect to cement, incorporation of calcined oyster and periwinkle seashells resulted in extended final setting times of the cement. In quantitative terms, it was observed that the final setting time of the cement was extended by an average of 14 and 28 ​min as the amount of oyster and periwinkle shell respectively introduced to the cement was increased from 5 to 15%. Conclusions drawn are that both the oyster shell powder and the periwinkle shell powder act as retarders. It is concluded that the filtration property of the seashells had a direct relationship with the amount of the seashell added. Economically, the pulverized seashells have comparable cost performance with the conventional filter loss and cement retarder additives. By utilizing these waste shells in this way, the overall well drilling cost would be reduced and the environment would be protected.

Ulrich Julius Lipidology and Center for Extracorporeal Therapy, Department for Internal Medicine III, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Dresden, Germany Abstract: This review reports the current situation with respect to therapeutic options (lifestyle and drugs) reducing the concentrations of atherogenic low-density lipoprotein cholesterol (LDL-C) and lipoprotein(a) (Lp[a]). Three lipoprotein apheresis (LA) principles have been realized: precipitation, filtration, and adsorption. Available LA methods are herein described in detail – major components, pumps, extracorporeal volume, treated volume, and anticoagulation. General features of all LA methods as well as pleotropic effects are elaborated. Indications for LA therapy are quoted: homozygous familial hypercholesterolemia (HCH), severe HCH, and isolated elevation of Lp(a) and progress of atherosclerotic disease. A major focus is on the evidence of the effect of LA on cardiovascular outcome data, and the most important publications are cited in this context. The best studies have been performed in patients with elevated Lp(a) in whom cardiovascular events were reduced by more than 80%. Major adverse effects and contraindications are listed. The impact of an LA therapy on patient quality of life and the requirements they have to fulfill are also highlighted. Finally, the future role of LA in treating high-risk patients with high LDL-C and/or high Lp(a) is discussed. It is probable that the significance of LA for treating patients with elevated LDL-C will decrease (with the exception of homozygous familial HCH) due to the application of PCSK9 inhibitors. The antisense oligonucleotide against apolipoprotein(a) could replace LA in patients with high Lp(a), provided positive outcome data are generated. Keywords: LDL cholesterol, lipoprotein(a), lipid-lowering therapy, lipoprotein apheresis, cardiovascular outcome

The phytoextraction of some toxic heavy metals from municipal waste dump soil by castor plant (Ricinus communis) was tested under natural and single or mixed chelant-assisted scenarios in pot microcosms. A sandy loam with total metal contents (mg/kg): Cd (84.5), Cu (114.5), Ni (70.3), Pb (57.8), and Zn (117.5), was sampled from an active dumpsite in Calabar, Nigeria and used for the study. Castor (small seed variety) was grown under natural phytoextraction or single/binary chelant (citric acid, oxalic acid, and EDTA) applications (5-20 mmol/kg soil) for 63 days. Castor exhibited no visual phytotoxic symptoms with typically sigmoid growth profiles at the applied chelant doses. Growth rates, however, decelerated with increase in chelant dose. Post-harvest biomass yields were higher under chelant application than for natural phytoextraction. Both root and shoot metal concentrations (mg/kg) increased quasilinearly and significantly (p