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Quercetin rich compound and cardanol rich compound were extracted and modified via the William ether synthesis using 1,2-dibromoethane in the presence of a base catalyst. The FTIR spectral analysis of the modified product confirmed its chemical modification. The modified product MRCNSL was evaluated as emulsion breakers. Medium crude and seawater, characterized with ASTM standards were used in producing laboratory-simulated crude oil emulsions at varying crude oil: water mixing ratios of 90:10, 70:30 and 50:50. Performance of MRCNSL demulsifier was evaluated based on variation in dosage (10 ppm – 50 ppm), water content (10%, 30% and 50%), and solvent types (ethanol, butanol, xylene and a binary mixture of butanol and xylene in ratio 30:70, 50:50 and 70:30) at room temperature within a 3-hr period via bottle testing. Results obtained showed that water separation increases with demulsifier concentration and emulsion water content respectively, though water separation varied among the solvents. In conclusion, the evaluated MRCNSL product possesses emulsion breaking potential using binary mixture of Butanol/xylene (70:30) as solvent at shorter times. This may be due to the synergetic effect of Butanol as a solvent, thus, Butanol/xylene (70:30) should be considered as solvent substitute for xylene due to reduced cost and less toxicity levels, unlike using xylene alone which is toxic and expensive.

Aim: Polymer flooding is a promising chemical enhanced oil recovery. Originally it was thought that polymer flooding was not economical. The polymer flooding in Daqing field China has proved otherwise. After that, it was thought that polymer flooding could only be successful in light oil reservoirs, but then polymer flooding was implemented in Pelican field in Canada on a large scale and recorded success. Methodology: The methodology employed was to review polymer flooding from inception, beginning from the work of Kingsley Detling in 1944 who got a patent in the USA to late 1970’s, thus early history of polymer flooding was a good insight for this paper. The mechanism of polymer flooding was also captured; improving the mobility ratio of water with a water soluble polymer is what helps for better sweep efficiency. The successful polymer flooding in Daqing field China has made many companies to understand this technology and go for polymer flooding. Polymer flooding of Daqing field has helped China’s oil and gas industry. Polymer flooding is now used to recover heavy oil especially for deep reservoirs with thin pay zone. Pelican field in Canada has carried out the largest polymer flooding implementation in the world and has proven that polymer flooding can be used for heavy oil and given a new screening parameter for polymer flooding. Results: This review has captured the critical aspects of polymer flooding both in light oil reservoirs-Daqing field, China and heavy oil reservoirs-Pelican field, Canada. Conclusion: This review has proven that polymer flooding is a promising Chemical Enhanced Oil Recovery technology in both light oil and heavy oil reservoirs and it is used to increase the ultimate recovery of some fields and could help any country to remain relevant in the oil and gas sector. Using polymer flooding to recover heavy oil proves more efficient and more economical. Because, polymer flooding does not require a lot of heat as in thermal flooding, there is reduction in global green house gas effect. Recommendation: It is recommended that companies use polymer flooding to recover their oil from light oil reservoirs and most importantly increase production and recovery in heavy oil fields.

There has been an increase in demand for green demulsifiers that will be as effective as the chemical demulsifiers but without the negative environmental effects. This demand has been partly addressed with the production of some bio-based demulsifiers. It is of importance to know the substances that act as emulsifiers in the production of crude oil and understand the mechanism of emulsification. This paper has reviewed emulsifiers and the mechanism of emulsification as well as bio-based demulsifiers and their mechanisms. This will enhance our knowledge on the type of compounds that can be used in the formation of effective demulsifiers. Innovation of these demulsifiers will enhance crude oil production and in the long run boost profitability and environmental sustainability. Currently, cashew nut shell liquid (CNSL) derivatives are in use for the formulation of effective green demulsifiers for water-in-crude oil emulsions.

With growing awareness of the environmental impact of some conventional production chemicals and concerns about the depletion of non-renewable natural resources, increased efforts are being made to use renewable and non-toxic materials in the oilfield. In this study, a potential green scale inhibitor was developed from the skin of red onions and evaluated for calcium sulphate, calcium carbonate and barium scale inhibition. Based on the different extraction processes utilized, two products were obtained and characterized using FTIR and SEM and evaluated using a static jar test procedure. The FTIR results confirmed the bands that make up the major constituents (quercetin) and other important compounds, which supports the present study. Laboratory evaluation show that ROSE can efficiently inhibit calcium sulphate scale and barium sulphate scales with a good inhibition rate of greater than 75% at an optimum dosage. Effect of temperature and dosage on inhibition performance revealed that ROSE is stable at higher temperatures and can effectively inhibit calcium and barium sulphate scales at nearly the same rate without degradation but requires additional dosage to produce same result for calcium carbonate scale. Also, the effect of time reveals that scale inhibitor performs a continuous CaSO4 and CaCO3 inhibition. Not only does ROSE perform excellently in the laboratory condition as a green scale inhibitor, but it also show a relatively close performance rate when compared to an existing commercial inhibitor which indicate that ROSE has a high potential for use in the oil industry.

Scale deposits are a significant flow assurance issue in oil and gas operation with huge financial consequences. Not only does scaling drastically impair well performance, but it also has the potential to permanently destroy formation and equipment. Scale inhibitors are commonly used to prevent the accumulation of scales. A good scale inhibitor should be stable at the minimum effective inhibitor concentration under imposed operating conditions without interfering with or being affected by other chemical additives. However, most conventional scale inhibitors that possess these attributes, do not meet environmental restrictions which make them unfavorable for continuous application, prompting the industry to focus more on developing eco-friendly substitutes. This paper reviews the various types of scale inhibitors and general scale inhibition mechanism, summarizes scale concepts and ultimately, assesses the potential of flavonoids from natural plants as potential green scale inhibitors.

Aim: Polymer flooding is used for enhanced oil recovery. Only polymers that can withstand harsh environments work best. HPAM is mostly the polymer used for enhanced oil recovery because it is available and cheap, but it does not withstand high temperatures and high salinity reservoirs. Xanthan Gum withstands high temperatures and high salinity reservoirs, but it is expensive and plugs the reservoir. The aim of this study is to compare the salinity stability of gum Arabic and Terminalia Mantaly, a novel biopolymer, with commercial Xanthan gum. Study Design: Locally formulated biopolymers from gum Arabic exudates bought from Bauchi State in Nigeria and from Terminalia Mantaly exudates obtained from the University of Port Harcourt. The appropriate rheological tests were carried out at the laboratory. Place and Duration of Study: The laboratory experiments were carried out at the department of Petroleum Engineering, Covenant University, Ota in Ogun State of Nigeria between 2020 and 2021. Methodology: The gum Arabic, Terminalia Mantaly and Xanthan Gum powders were dissolved in deionized water to get various concentrations in ppm. The polymers were mixed and kept for 24 hours to achieve a homogenous solution. The Automated OFITE® Viscometer at different revolutions per minute (RPM) of 3 (Gel), 6, 30, 60, 100, 200, 300, and 600 was used to measure the rheological properties of the various concentrations before Sodium Chloride (NaCl) and Calcium Chloride (CaCl2) of various concentrations were added and allowed to hydrate for another 24 hours before measuring their rheological properties again. Results: The study showed that Xanthan Gum, Gum Arabic, and Terminalia Mantaly biopolymers can be used in high salinity reservoirs. Terminalia Mantaly, a novel biopolymer, is insensitive to salinity in monovalent and divalent ions. Conclusion: Xanthan gum exhibited high viscosity even at low concentrations. Gum Arabic exhibited good tolerance to salinity at NaCl 3.5%. Terminalia Mantaly was very stable with both monovalent and divalent ions. Divalent ions have more effects on polymers than monovalent ions in reservoirs. Recommendation: It is recommended that Terminalia Mantaly be investigated more, as it can replace imported biopolymers for Enhanced Oil Recovery (EOR).

Crude oil induced pollution on soil environment is an increasing trend due to incessant accidental release of this component into the environment. Bioremediation which is considered the most effective clean-up tool is faced with the challenge of sustained nutrient delivery to enhance and sustain the activities of oleophilic microbes. Slow release fertilizer (SRF) is a purposely designed system that releases nutrients in synchrony with sequential needs of organisms hence they provide optimized nutrient use efficiency. This approach aids in mitigating challenges associated with the conventional fertilizer application such as eutrophication, soil hardening, increased fertilizer loss rate and other environmental devastation. Superabsorbent polymers are hydrophilic gels as they exhibit the ability of swelling and retaining water which supports its use in SRF production. Most SAP used in practice are synthetic and semi-synthetic polymers with high production cost and environmentally unfriendly properties. Natural based polymers such as guar gum, cellulose, chitosan, and starch are abundantly available from plant and other sources but most of these biopolymers have other application which may lead to scarcity for other uses. In most part of the world, enormous quantity of waste is generated which invariably causes pollution. World agro and industrial waste materials with little or no value is therefore recommended to be applied as SAP for SRF formulation. This review therefore provides insight on the potential use of controlled release fertilizer system as a useful tool in ensuring sustained nutrient delivery during bioremediation and also suggest more eco-safe and cost-effective approaches of SRF formulation. Key words: Hydrocarbons, encapsulation, degradation, organic fertilizer.

This study investigated the removal of Lead and Cadmium ions from aqueous solution using activated carbons from agricultural wastes. Activated carbons prepared by chemical activation using Phosphoric acid were characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The influence of contact time, initial concentration and adsorbent dose which governed the efficiency of the process was ascertained through batch adsorption studies. Adsorption isotherms were determined by correlating with Langmuir and Freundlich isotherms and the kinetic studies were correlated with pseudo first order and pseudo second order equations. The results showed that the amount of Lead and Cadmium adsorbed decreased as the adsorbent dose increased while the adsorption capacity increased with increased in contact time and initial concentration. Activated carbons prepared from Coconut shell and palm kernel (shell and cake) competed favorably with the commercial activated carbon in percentage removal of the metal ions as all the activated carbons had over 90 % removal within 60 minutes when 1g of adsorbent was used. The equilibrium data fitted best into Freundlich isotherms for both metal ions. The rate of adsorption could be described by pseudo second order for all the adsorbents except Coconut shell activated carbon in the adsorption of Lead while intra-particle diffusion was the limiting step for Cadmium adsorption. Therefore, the agricultural by-products can be used as effective, low-cost, and environmentally friendly adsorbents for domestic water treatment in many parts of the world.

Wax crystallization and deposition is a major flow assurance problem in production and transportation of waxy crude oil. Conventional flow improvers are mainly high molecular weight synthetic polymers, many of which are eco-toxic. Bio-based flow improvers derived from natural products are promising as inexpensive, eco-friendly alternatives to existing products. In this study, natural cashew nut shell liquid (CNSL) extracted from waste shells ofAnacardium occidentalewas esterified with polyethylene glycol (PEG). CNSL derivative reduced the pour point of waxy crude oil by 12 °C at 1000 ppm. The effects of CNSL derivatives on wax crystal morphology and micro-structure were studied by cross-polarized microscopy. Micrographs were processed and analyzed with ImageJ software. Addition of CNSL derivatives to oil resulted in changes in wax crystal morphology and micro-structure evidenced by a reduction in average crystal Feret diameter and aspect ratio and increase in boundary fractal dimension, indicative of formation of increasing number of smaller, rounder crystals. Effect of the additives on flow properties of the waxy oil was determined using a co-axial cylinder rotational viscometer. Dynamic viscosity of oil at shear rate of 17 s−1was reduced by 79.7–90.5%. CNSL-PEG esters show good prospects as low-cost additives for production, storage and pipeline transportation of waxy crude oil.

Control and management of corrosion have always been the concern of oil and gas asset management teams due to the challenging outcomes of failed facilities in service due to corrosion. Corrosion has an impact on human safety, environmental safety, and productivity; thus, it is important to know how corrosive an environment is in order to make the best investment decisions for facilities that are prone to corrosion. There are various ways of identifying environmental corrosivity, but there is no distinct map or relation with combined soil pH and resistivity impact unique to an environment that suggests the corrosion severity of such an environment, which could be due to the complexities of variables involved in defining the extent of corrosivity. This research aims to create a corrosion map using the MATLAB computing environment for Rivers State, a mega oil-producing state in the Niger Delta, based on soil resistivity and pH across different parts of the state with ongoing oil and gas activities for the purpose of a quick look decision-making guide. To determine corrosivity, such a map should only need to identify the soil resistivity and pH of a certain site. The pilot test conducted using 40-point soil pH and resistivity data suggested that it is feasible to develop a unique corrosivity map for a region since the result showed an R-square value of 70.03%. However, possible constraints of the mapping process were discussed, as well as suggestions for a wider survey and improvement.

The challenge of data availability for accurately assessing a location's level of corrosivity has lingered for so long and as such, researchers are constantly seeking factors with great influence that can assist in describing how corrosive a location will be toward buried oil and gas infrastructure. Alternative measures are required for making rapid and realistic investment decisions because accumulating these factors to make perfect sense is sometimes time-consuming and expensive. Using MATLAB mathematical computational analysis, this study capitalizes on this gap to build a 3D corrosivity signature and model for Delta state, Nigeria to aid in rapid and realistic investment decision-making. The soil pH and resistivity were identified as key variables that determine the extent of corrosion in this investigation. Vertical Electrical Soundings were utilized to collect soil resistivity data, which was then combined with the soil pH to create a 3D corrosivity signature and model with a 98% R-square factor. During the study, potential limitations were found, and recommendations were made.

It is difficult to simply bury a pipeline beneath the ground without facing corrosion challenges, yet it is important to do so for both the search for crude during drilling and pipe laying for oil and gas transportation. The oil and gas business has lost millions of dollars owing to corroded pipes, making it vital to evaluate the severity of environmental corrosion before making investment decisions. The Niger Delta, which is a hub of oil and gas activity in Nigeria, was the focus of this research. This research aims to reduce the impact of environmental corrosion on buried oil and gas assets by creating a corrosion map and model tailored to the environment in order to identify the level of corrosion severity at various points. 93-points soil resistivity data were collected using Vertical Electric Sounding (VES) and the Werner method, while average pH data from Rivers, Bayelsa, and Delta States were gathered from research within the Niger Delta. The extent of corrosivity in the environment was estimated using both the soil resistivity data and pH data. As an enhancement over the traditional method of employing ranges, a model was developed to determine the exact corrosion severity of the environment based on its soil resistivity. In addition, MATLAB was used to create a 3D planar curve and a map that could be used to quickly evaluate the corrosion severity of regions in the Niger Delta. This research paved the way for the continued development of corrosion severity maps unique to distinct oil and gas activity regions, as well as advancements in asset management for buried oil and gas assets.

The oil and gas business is serious business and involves millions of dollars so whatever mitigates flow assurance is taken seriously. One of such things is natural gas hydrates. Hydrates are crystalline solids formed when water under low temperatures and high pressures encapsulated natural gases (C1–C4). They form blockages and impede the flow of gas which can lead to the loss of millions of dollars and at times lead to personnel death. Mitigation of gas hydrates has always been with chemicals especially for areas like deep offshore where accessibility is difficult. The chemicals that are in use currently are generally synthetic, expensive and hazardous to lives and environment hence the need for readily available locally sourced materials that are eco-friendly. This study considers and screens a locally sourced surfactant from the plant family caricaceae’ Extract (CE) as a gas hydrate inhibitor in a locally fabricated 39.4-inch mini flow loop of ½ inch internal diameter (ID) which mimics the offshore environment. Various pressure plots (pressure versus time, initial and final pressure versus time and change in pressure versus time) show that the CE performed better than MEG with percentage volumes of gas left in the system for 0.01–0.05 wt% of the extract having values that ranged from 76.7 to 87.33, while volume left for MEG ranged between 70 and 74.67% (1–5 wt%). The CE performed better in small doses compared to those of MEG, in all weight percentages of study. Furthermore, the inhibition capacities which show the level of performance of the inhibitors was also used as a measure of inhibition for both inhibitors. The CE inhibited systems had values of 69.3, 80.7, 78.07, 79.82, and 83.3%, while that of the MEG inhibited system was 60.53, 55.26, 73.68, 72.81, and 66.67% for the various weight percentages considered. The CE should be developed as gas hydrate inhibitors due to its effectiveness and eco-friendliness.

The extensive use of commercial activated carbon as an adsorbent for the purification of industrial effluent is not economical for small and medium-sized enterprises due to its high operational cost. This study was carried out to compare the adsorptive capacity of bentonite clay and activated corn cob (“BC” and “ACC”) for the removal of lead (II) and nickel (II) ions from an aqueous solution. The results obtained from the characterization of the BC and ACC are pH: 7.43 and 6.74; moisture content: 36.45kg/kg and 12.10kg/kg, and bulk density: 1.243g/ml and 1.162g/ml, respectively. Normality tests using the coefficient of skewness indicated that the set of data was not normally distributed. An analysis of variance (ANOVA) test conducted using Friedman’s 2-way ANOVA test indicated p values of 0.0253 against an alpha value of 0.05, which indicates significance. The Friedman results indicated significance with respect to the varied dosages, initial concentrations, and contact time. The effect of the adsorbent was not significant. The adsorption isotherms were analysed using the Langmuir, Freundlich, and Temkin isotherms. Most research studies have shown that adsorption experiments performed using most low-cost materials tend to follow the Freundlich adsorption isotherm, but the results of this experimental study proved that activated corn cob and bentonite clay performed better with the Temkin adsorption isotherm with 0.879 ≤ R2 ≤ 0.917 for the bentonite clay and 0.9572 ≤ R2 ≤ 0.99 for the activated corn cob respectively. The study revealed that these materials are good adsorbents that can be used for the removal of lead (II) and nickel (II) ions from an aqueous solution.

The quest for green and sustainable biofuel to serve as alternative to the conventional fossil fuel have remained a grey area in biotechnology. The Chlorella vulgaris was isolated from the African Regional Aquacultural Centre Aluu, Port Harcourt, Nigeria. Sugarcane Molasses modified Bold Basal medium was used to cultivate the Microalgae mixotrophically. The algal culture was incubated at room temperature for 15 days with continuous aeration and 12:12 hour photoperiod under artificial illumination of 2000 lux. The proximate composition of the biomass showed 6.28%wt, 67.37% wt and 11.35%wt of moisture, volatile organic matter and Fixed carbon content respectively. The ultimate composition of Chlorella biomass revealed that Carbon was 42.46% while Oxygen content was 27.93%. Nitrogen content was 6.62% while Sulphur content was 0.82% while hydrogen content was 6.74%. The study further identified that algal biomass from C. vulgaris has the potential of serving as both nutraceuticals and bioenergy feedstock. There is need for further studies around the algae oil oriented optimization as a veritable tool for biotechnological advancements.

Purpose This study aims to synthesize pigment and resin from agro-wastes and use them in the formulation of eco-friendly surface coatings. Design/methodology/approach The pigments and resin were synthesized through a chemical modification of agro-wastes. The pigments were characterized by infrared spectroscopy (FTIR) and were screened for their antimicrobial activities. The physicochemical characteristics of the cashew nutshell liquid (CNSL)-modified resin were evaluated. These precursors and other natural additives were used to formulate surface coatings, and their drying and adhesive properties were evaluated using international testing methods. Findings It was observed that the curing of the CNSL-modified resin depended on time and temperature. The pigments exhibited antimicrobial activity against E. coli and S. aureus and had high melting points, affirming their stability. The chemically modified precursors successfully yielded surface coatings with acceptable drying times and adhesion to the base substrate. Practical implications The use of agro-wastes as the main components of the surface coatings implies waste valorization, a reduction in production costs and the creation of job opportunities for sustainable development. To increase the chemical, physical, corrosion resistance and antimicrobial qualities of paint compositions, chemically modified peanut skin extracts and CNSL can be used as pigments and resins, respectively. This could be a green approach to achieving the targets of Sustainable development goals 11 and 12. Originality/value The paper outlines a prospective approach to use unwanted waste (peanut skin, cashew nutshells) and other natural additives as industrial raw materials. These novel surface coating precursors are cost-effective, readily available, eco-friendly and could replace conventional precursors.

Response surface methodology (RSM) model was used to optimize ethanol production from calabash (Crescentia cujete) pulp juice using co-culture of Saccharomyces cerevisiae and Cronobacter malonaticus. The calabash pulp was squeezed with muslin cloth, and vacuum filtered to clear solution before use. The clear juice was tested for reducing sugars using the Dinitrosalicylic acid (DNS) method. Twenty three runs (23), including 3 controls, of the fermentation were conducted at varying temperatures, pH, and volumes of inoculum. The process parameters (input variables): volumes of inoculum, temperature, and pH were subjected to response surface model, using the Central composite design (CCD). Fermentation was done in conical flasks covered with cotton wool and foil in a stationary incubator for four days (96 hours). Active co-culture of Saccharomyces cerevisiae and Cronobacter malonaticus was used, with inoculum developed using Marcfaland’s method. Samples were collected every 24 hours, centrifuged, filtered and analyzed for measurement of the output variables: reducing sugar, cell density and ethanol concentration. The concentration of reducing sugars from Calabash pulp was 3.2 mg/ml. Results obtained also revealed that the fermentation can take place on a wide range of temperature; 29-31.60C . The optimal pH range for performance of the co-culture for the fermentation process was pH range 7.9- 8.0. The optimum volume of inoculum was 5.5%v/v (ie 5.5 ml in 94.5ml juice). The optimized process using the RSM model gave 6.97% v/v bioethanol at 29oC and pH 7.9. The bioethanol yield from Calabash substrate is reasonable with co-culture considering the concentration of reducing sugars obtained from the juice and the duration of the fermentation.

Three bio-based crude oil emulsion breakers have been prepared from agricultural waste by chemical treatment of cashew nutshell liquid (CNSL) extract with triethanolamine via a one-pot reaction at 120 ℃. The triethanolamine-ester derivatives were characterized by Fourier Transform–InfraRed spectroscopy. Their effectiveness as crude oil emulsion breakers were investigated experimentally using the bottle test method. The effect of solvent type, water content, and concentration of the emulsion breaker, was used to study the demulsification process and determine their demulsification efficiency at a temperature of 60 ℃ for a contact time of 180 min. A commercial demulsifier, PhaseTreat 4633 (PT-4633) was used as a benchmark. Performance evaluation of the prepared emulsion breakers revealed their effectiveness in descending order as: triethanolamine dianacardate (TED) > triethanolamine trianacardate (TET) > triethanolamine anacardate (TEA). The data reveals that their emulsion breaking efficiency increases with increasing emulsion water content, and concentration. PT-4633 exhibited better demulsification efficiency than the triethanolamine-esters in xylene across the concentration and water content studied. Improved water separation was however observed for the triethanolamine-esters in butanol, as triethanolamine trianacardate (TET) performed better than PT-4633 at 10 ppm to 20 ppm at 30% water content with a water separation of 83.33% and 80% respectively. The evaluated triethanolamine ester derivatives exhibited better emulsion breaking potentials in butanol than xylene at shorter times, which may be due to the synergistic effect of butanol. Therefore, butanol could be used as a sustainable solvent substitute for xylene in demulsifier formulations.

Aim:Response surface methodology (RSM) model was applied to optimize ethanol production from Calabash (Crescentia cujete) pulp juice usingCronobacter malonaticus. Study Design:The Calabash pulp was squeezed with muslin cloth, and vacuum filtered to clear solution before use. The clear juice was tested for reducing sugars using the Dinitrosalicylic acid (DNS) method. Twenty three (23) runs, including 3 controls, of the fermentation was conducted at varying temperatures, pH, and volumes of inoculum. The process parameters (input variables): volumes of inoculum, temperature, and pH were subjected to response surface model, using the Central Composite Design (CCD). Place and Duration of Study:This study was carried out in the Environmental Microbiology Laboratory, University of Port Harcourt for six months. Methodology:Fermentation was done in conical flasks covered with cotton wool and foil in a stationary incubator for four days (96 hours). Active stock culture ofCronobacter malonaticuswas used, with inoculum developed using Marcfaland’s method. Samples were collected every 24 hours, centrifuged, filtered and analyzed for measurement of the output variables: Reducing sugar, cell density and ethanol concentration. Results:The concentration of reducing sugars from Calabash pulp was 3.2 mg/ml. Results obtained also revealed that the fermentation can take place on a wide range of temperature 28-32°C. The optimal pH range for performance ofC.malonaticusfor the fermentation process was pH 5.95-6.5. The optimum volume of inoculum was 10%v/v (i.e. 10 ml in 90 ml juice). The optimized process using the RSM model gave 5.08% v/v bioethanol, being the highest achieved at pH6.08 and 28oC . Conclusion:The bioethanol yield from Calabash substrate is reasonable considering that the bacterium used is not known for ethanol production. Also the concentration of reducing sugars in the substrate and the duration of fermentation could be responsible for the yield.

Wax formation creates flow assurance problems in the production and transportation of waxy crude oil. Flow improvers are added to waxy crude in order to reduce handling cost. Bio-based flow improvers derived from cheap renewable resources are attractive as cost-effective, eco-friendly alternatives to the conventional additives. Natural cashew nut shell liquid extracted from waste biomass (Anacardium occidentale shells) was derivatized and applied as flow improver for waxy crude oil. Effect of the additive on wax formation in crude oil was studied by cross-polarized microscopy, while the change in oil flow properties was evaluated using a rotational coaxial cylinder viscometer. Micrographs of the waxy crude were processed and analyzed with image J software. The microscopic properties of the wax crystals were characterized using Feret diameter, crystal area, aspect ratio, circularity, solidity and boundary fractal dimension. The pour point of doped crude oil was depressed by − 18 °C and the wax area fraction reduced by 40% due to wax inhibitive effect of the additive. The presence of the additive resulted in evolution of smaller, rounder and more regular wax crystals with smoother and more even surfaces indicated by reduction in the Feret diameter, aspect ratio and boundary fractal dimension of wax crystals in doped oil, and an increase in crystal circularity and solidity. The shear stress and viscosity of doped oil were reduced by 86.8% and 85.0%, respectively. The flow improvement effect of the CNSL derivative is linked to its effect on morphology and microstructure of wax crystals in the crude oil.

Use of pour point depressants/flow improvers is an effective strategy for alleviation of flow problems associated with wax formation in paraffinic crude oil. Biobased oilfield chemicals derived fro...

Cashew Nut Shell Liquid (CNSL), a natural phenolic liquid, was extracted from cashew nut shells using acetone and derivatized using Ethanolamine (EA) and Diethanolamine (DEA) in varying molar ratios via a one-pot process into anacardic acid-based ethanolamine esters and evaluated for use as crude oil emulsion breakers. The CNSL extract was characterized for its physico-chemical properties, FTIR spectral analysis for CNSL and the derivatives confirmed its chemical modification. Medium heavy crude and seawater sampled and characterized with ASTM standards were used in producing laboratory-simulated crude oil emulsions at varying crude oil: water mixing ratios of 90:10, 70:30 and 50:50. Performance of the anacardic acid-based CNSL extract and derivatives as demulsifiers were evaluated based on variation in dosage (10 ppm – 50 ppm), water content (10%, 30% and 50%), and solvent types (xylene and butanol, BuOH) at 60℃ within a 3-hr period via bottle testing. The performance of effective demulsifier formulations were compared with a commercial demulsifier, Phase Treat-4633, PT-4633, under similar conditions. Results obtained showed that water separation increases with demulsifier concentration and emulsion water content respectively, though water seperation varied among the demulsifiers as concentration and water content increased. PT-4633 in butanol achieved efficient water separation with an optimal seperation (100%) observed after 5 minutes at 40 ppm and 50 ppm, 50% and 60℃. In conclusion, the evaluated ethanolamine-CNSL products possess emulsion breaking potential using BuOH as solvent at shorter times. This behaviour may be due to the synergetic effect of BuOH as a solvent, thus, BuOH should be considered as solvent substitute for xylene due to low cost and toxicity levels, unlike xylene which is toxic and expensive.

There has been a global concern about the use of tributyltin-based coatings in combating biofouling in the marine industry. Although there have been alternatives to tributyltin in preventing biofouling, the emphasis is now on the use of nontoxic and/or ecofriendly natural materials which do not negatively affect the environment upon application. Natural materials are ecofriendly, biodegradable, cost-effective, and can be employed as precursors in the synthesis and formulation of biodegradable antifouling coatings. Consequently, many researchers are investing time into the synthesis and formulation of natural, ecofriendly antifouling coatings, comprised of higher biofiber, which would perform analogous antifouling like other conventional coatings, thus minimizing the more toxic base polymer proportion. A safe environment is surely the signal of a bright future; hence, cost-effective, biodegradable raw materials result in a long-term attainment of sustainability of these products to replace the expensive conventional ones. This review presents an overview of ecologically friendly, cost-effective, and legally acceptable ways of preventing and mitigating the growth of algae and other marine organisms from settling on the hull of a ship and other static constructions in oilfields.

Cashew Nut Shell Liquid (CNSL), a natural phenolic liquid extracted from locally sourced raw materials, and Phasetreat-4633 (a commercial demulsifier) were diluted with xylene and butanol and used as demulsifiers in the treatment of crude oil emulsions. Laboratory simulated crude oil emulsions dosed with different concentrations of CNSL and PT-4633 were the basis for comparison of demulsifier performance via the bottle test method. Different factors affecting demulsification efficiency such as; water content, demulsifier concentration, and solvent type were investigated at 10%, 30%, and 50% water content. The data obtained showed that the rate of water separation increases with increasing concentration and water content of the demulsifiers and emulsion respectively. Among the demulsifier-solvent combination employed in this study, Phasetreat-4633 in butanol recorded the most efficient water separation with optimal (100%) separation recorded after 5 minutes at 40 ppm and 50 ppm concentration, 50% water content and 60℃. From the obtained results, the investigated demulsifiers have great potential with butanol as a solvent in the resolution of crude oil emulsions in shorter times. This behavior can be attributed to the synergetic effect of butanol as a solvent. Hence, butanol can be regarded as a better solvent substitute to xylene, due to its attributive synergetic effect, low cost and toxicity levels, unlike xylene which is more toxic and expensive.

This paper aimed at improving the water-based drilling mud using Moringa oleifera (M. Oleifera) plant leaves. The rheological properties (plastic viscosity (PV), yield point (YP), and gel strength) of the mud were measured using standard procedures. The mud weight was not affected by M. oleifera concentration (10.03-10.63 pounds per gallon (ppg)). pH of the formulated mud decreased by 28% with increasing concentration of the M. oleifera leaves. The highest PV (33cP) was recorded by mud with 1% M. oleifera leaves at 50ºC while the least value (22cP) was given by control mud at 70ºC temperature. Highest YP (57 1b/100ft2) was recorded by mud sample with 4% concentration of M. oleifera leaves while 1% gave the lowest YP value of 91b/100ft2 at 30ºC and 49ºC respectively. Gel strength at 10 seconds showed improvement with 2% concentration of leaves by recording maximum of 5 1 b/100 ft2 at 70ºC while the lowest gel strength was recorded by 1% leaves concentration at 49ºC. A good gel strength (30.21 b/100 ft2) at 10 minutes was recorded by mud sample with 3% leaves of M. oleifera at temperature of 30ºC. The results indicated that the M. oleifera leaves significantly improved the rheological properties of the mud. It was also observed that the mud weight of formulated muds with M. oleifera leaves were not affected which leads to stability of the wellbore if the formulation is used. These great result calls for the need to use M. oleifera leaves to improve rheological properties of the drilling mud. An investigation of M. oleifera as fluid loss control should be done as well as need to carry out isolation and characterization of the active ingredients from M. oleifera leaves so as to establish the compound (s) associated with its activity in drilling mud.

In this study, cashew nut shell liquid has been extracted from cashew nut shells using an accelerated solvent extraction technique and was employed as a precursor for the synthesis of cashew nut shell liquid resin. The extract was a dark brown viscous liquid with an average yield of 30.61±0.200%. Results of the physical analysis showed a moisture content of 4.45±0.020% and a density of 0.95±0.300 gcm-3. The percentage brix and refractive index were 76.20±0.001 and 1.47 ±0.010 respectively. Chemical characterization showed a pH of 5.65±0.003; acid value of 8.25± 0.200 mg KOH/g; ash content of 1.80±0.6%; free fatty acid of 4.12±0.400 mg KOH/g; ester value of 247.01±0.100 mg KOH/g and a saponification value of 255.26±0.800 mg KOH/g. The FTIR spectra revealed that cashew nut shell liquid is polymeric. These findings confirm that higher phenolic compounds which can be used as potential precursors in industrial applications could be obtained from agro wastes. Practical Applications: Cashew nut shell liquid, an extract from cashew nut shell, an agro waste has a wide range of functional products. A practical application is synthesis of a high viscous, flexible cashew nut shell liquid resin with physical properties that are consistent with literature and could also be further used in other industrial applications. Further processing of cashew nut shell for the development of value added products like resin can be a better option.

The corrosion inhibition characteristics of Sulfadoxine plus Pyrimethamine (S&P) was evaluated and compared with the inhibition performance of an industrial corrosion inhibitor (S-Ind) under anaerobic condition. Modified gravimetric and electrochemical techniques were used. The corrosion inhibition efficiencies of both S&P and S-Ind were comparable for all the techniques applied. S&P gave slightly higher inhibition efficiency, while S-Ind gave a more steady corrosion protection. The corrosion inhibition efficiencies increased with increased concentration of both substances. The polarization curves showed mixed inhibition behavior for both S&P and S-Ind. A mechanism of chemisorption was proposed for the adsorption of S&P and S-Ind on pipeline steel surface, while the negative Gibbs free energy of adsorption values indicates a spontaneous adsorption process. The adsorption characteristics of the inhibitors were fitted into Langmuir adsorption isotherm. Keywords: Adsorption, Anaerobic, Corrosion, Inhibitor, Modified gravimetric, Pipeline steel

Process facilities for the separation of hydrocarbons from produced water in the oilfield are critical to flow assurance, product quality and environmental compliance. The formation of metal naphthenates, which are emulsion stabilizers and equipment foulers, is deleterious to performance and integrity of these processes and facilities. Manual removal of deposits of these organic salts formed at the oil–water interface during separation processes is difficult and expensive; hence, the best operational option is inhibition. The conventional method for the inhibition of metal naphthenates, which relies on suppressing the deprotonation of naphthenic acids by common ion effect, is no longer tenable because it exacerbates internal corrosion problems in topside facilities. Current industry focus is on the development of effective surface active agents for inhibition of naphthenates. There are a plethora of chemical compounds with naphthenate inhibition potential such as sulphonates, phosphate esters, aminated phosphonates and sulphosuccinates, but compatibility issues make the choice of inhibitor a complicated process. In this paper, the drivers and mechanism of oilfield metal naphthenate formation are reviewed. Surfactants for oilfield metal naphthenate inhibition and the mechanisms of inhibition are highlighted with a view to process optimization.

Present investigation aims for the synthesis and characterization of a new eco-environmental and cost-effective silver nanocomposite (AgNPs) for application as multifunctional inhibitor of scaling and corrosion. The AgNPs was synthesized by reduction of silver ions using Allium cepa peels extract. The AgNPs exhibit impressive stability and resistance to thermal and biochemical degradation. The AgNPs were round shaped, monodispersed and non-aggregated, with surfaces rich in oxygen and nitrogen sites. Compared to the crude extract, AgNPs exhibits higher antimicrobial activity and afforded a 3-log reduction in population of Desulfovibrio sp. At 30 ​°C, AgNPs inhibits carbonate scale, sea water corrosion and bio-corrosion at efficiencies of 30.8%, 14.4% and 55.9%, respectively, and 37.4%, 37.3%, 45.6%, respectively at 60 ​°C. AgNPs sustained its high efficiency even after being preserved for 180 days and addition of d -tryosine and mevalonic acid phosphate further intensified the efficiency by synergistic effect.

Gas hydrate inhibition through the use of chemicals has been ongoing over the years and these chemicals are toxic, synthetic and expensive, adding to the cost of doing oil and gas business, and also leads to environmental degradation. The call for greener environment has necessitated the search for more eco-friendly gas hydrate inhibitors. This paper takes a look at the use of a bio-extract in its unmodified state to inhibit gas hydrate using a locally made mini flow loop for gas hydrate studies. The bio extract was compared to a conventional gas hydrate inhibitor 2-Di(methylaminoethyl)methacrylate (2-DMAEM). For all the weight percentages considered (0.01-0.05wt%), the bio-extract had better pressure profiles. At the end of the experiment which lasted for 120 minutes, this is attributed to the fact that the pressures in the system were more regulated which prevented rapid gas dissolution in water. The Bio-extract is plant based, locally available in the commercial quantity and is eco-friendly so it should be harnessed as gas hydrate inhibitors in lieu of the expensive and imported conventional hydrate inhibitor 2-DMAEM which non-eco-friendly.

Gas hydrates are impediments to flow of gas and oil and its avoidance and mitigation is key to oil and gas operators. Mitigation via chemical controls is more suitable for marine environments. The effectiveness of 2wt% of an extract from the plant order, Zingiberales has been compared to that of Mono-Ethylene Glycol in a simulated offshore laboratory mini flow loop of 0.5-inch ID. The results from final pressure shows the value of ZE to be 107 psi while that of the MEG was 99 psi. The ∆P for ZE was 43 psi while that of MEG was 51 psi. The difference in ∆P was 8psi more than that of MEG. The Inhibition Capacity (%) values showed ZE to have performed better with a value of 62.28% while that of MEG was 55.26%. ZE had an Inhibition Capacity that was 7.02% more than that of MEG which is mostly imported and is termed a toxic alcohol, meaning that it is both human and environmentally hazardous. ZE therefore should be considered for development as a gas hydrate inhibitor.