As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crud...As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.展开更多
The Saltpond Basin,situated within the South Atlantic margin of Ghana,is a significant area for petro-leum exploration but has received relatively limited research attention.Previous studies have examined source rock ...The Saltpond Basin,situated within the South Atlantic margin of Ghana,is a significant area for petro-leum exploration but has received relatively limited research attention.Previous studies have examined source rock com-position,but data on crude oil organic chemistry are lack-ing,hindering understanding of the basin’s petroleum system and evolution.To address this gap,we analyzed biomarkers and stable carbon-isotope ratios in Saltpond Basin crude oil using gas chromatography–mass spectrometry and gas chromatography–isotope ratio mass spectrometry to eluci-date organic matter source,depositional environment,and thermal maturity.Findings were compared with oils from the West African segment of the South Atlantic margin,namely the Tano Basin and the Niger Delta Basin,to iden-tify potential correlations and gain insights into regional variations.Molecular and isotopic results unveiled a sig-nificant prevalence of organic matter derived from lower marine organisms.Patterns of organic matter deposition and preservation in Saltpond oil samples suggested a suboxic marine transitional environment,contradicting conventional understanding of terrestrial dominance in such settings.Moreover,the potential for degradation processes to obscure differentiation between terrestrial and marine organic mat-ter origins underscores the complex nature of organic mat-ter dynamics in transitional marine environments.Analysis of molecular thermal maturity indices suggested Saltpond oils were expelled from source rocks exhibiting thermal maturity at the early maturity stage.Correlation analysis unveiled genetic disparities among crude oils sourced from the Saltpond Basin and those from the Tano and Niger Delta Basin,primarily due to variations in source input and depo-sitional environment conditions.Saltpond oil exhibits lower terrestrial organic input than Tano Basin’s crude oils,which also have less terrestrial input than Niger Delta Basin crude oils.Additionally,its paleodepositional environment nota-bly differs from oils in the Tano Basin(anoxic transitional marine-lacustrine settings)and the Niger Delta Basin(sub-oxic–oxic terrigenous deltaic or marine or lacustrine envi-ronments).Thermal maturity range of Saltpond oil is com-parable to oils in the Tano Basin but lower than oils in the Niger Delta Basin.Thesefindings provide valuable insights into petroleum generation history and unique organic geo-chemical characteristics within the Saltpond Basin,essen-tial for exploration,production,and environmental manage-ment efforts in the region.Furthermore,correlation studies provide evidence that distinct biological,geological,and paleoenvironmental conditions shaped various oil types in the West African segment of the South Atlantic margin.展开更多
The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,Chad.The results suggest that diamondoids,including adamantanes...The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,Chad.The results suggest that diamondoids,including adamantanes(As)and diamantanes(Ds),are relatively resistant to biodegradation and obvious biodegradation was observed in oils with a Peters-Moldowan(PM)biodegradation rank of 6 or more.Overall,the sensibility of biodegradation on diamondoids is generally similar to hopanes and regular steranes.As biodegradation evolves,the changes in concentration and components of diamondoids show that the biodegradation process is selective and stepwise.The significant increase of MD/MA and DMD/DMA for oils with a PM ranking 6^(+) indicates that diamantanes are generally more resistant to biodegradation than adamantanes.The similar trends of DMA/MA,EA/MA,MD/D,DMD/MD and other relevant indexes,show that higher alkylation homologs are more resistant to biodegradation.The commonly used diamondoid ratios,such as MAI,EAI,MDI and DMID-1,are obviously affected by biodegradation at the stage of high-level biodegradation,which may indicate that these ratios should be used with caution in case of severely degraded oils.展开更多
Crude oil scheduling optimization is an effective method to enhance the economic benefits of oil refining.But uncertainties,including uncertain demands of crude distillation units(CDUs),might make the production plans...Crude oil scheduling optimization is an effective method to enhance the economic benefits of oil refining.But uncertainties,including uncertain demands of crude distillation units(CDUs),might make the production plans made by the traditional deterministic optimization models infeasible.A data-driven Wasserstein distributionally robust chance-constrained(WDRCC)optimization approach is proposed in this paper to deal with demand uncertainty in crude oil scheduling.First,a new deterministic crude oil scheduling optimization model is developed as the basis of this approach.The Wasserstein distance is then used to build ambiguity sets from historical data to describe the possible realizations of probability distributions of uncertain demands.A cross-validation method is advanced to choose suitable radii for these ambiguity sets.The deterministic model is reformulated as a WDRCC optimization model for crude oil scheduling to guarantee the demand constraints hold with a desired high probability even in the worst situation in ambiguity sets.The proposed WDRCC model is transferred into an equivalent conditional value-at-risk representation and further derived as a mixed-integer nonlinear programming counterpart.Industrial case studies from a real-world refinery are conducted to show the effectiveness of the proposed method.Out-of-sample tests demonstrate that the solution of the WDRCC model is more robust than those of the deterministic model and the chance-constrained model.展开更多
A total of 14 halophilic hydrocarbon-degrading strains were isolated from crude oil-contaminated sites,using petroleum as the sole carbon and energy source.Among these,four highly efficient strains were selected to cr...A total of 14 halophilic hydrocarbon-degrading strains were isolated from crude oil-contaminated sites,using petroleum as the sole carbon and energy source.Among these,four highly efficient strains were selected to create the mixed bacterial agent XH-1.These four strains were identified through 16S rRNA gene-based sequencing as belonging to Acinetobacter,Bacillus paramycoides,Rhodococcus sp.,and Enterobacter sp.,respectively.The optimal cultivation time for the mixed consortium XH-1 was found to be 48 h,and a nitrogen-phosphorus molar ratio of 10:1 was determined to be beneficial for crude oil degradation.XH-1 showed notable crude oil degradation even at a salinity of up to 30 g/L,with little inhibition observed at sulfide concentrations as high as 150 mg/L and initial oil concentrations of 500 mg/L.Gas chromatography analysis revealed that XH-1 was able to efficiently degrade C9–C29 n-alkanes.Moreover,a bio-contact oxidation reactor enhanced by XH-1 showed promising results in treating oilfield wastewater.These findings suggest that XH-1 can be applied for the treatment of oilfield wastewater.展开更多
Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the pres...Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.展开更多
A hard problem that hinders the movement of waxy crude oil is wax deposition in oil pipelines.To ensure the safe operation of crude oil pipelines,an accurate model must be developed to predict the rate of wax depositi...A hard problem that hinders the movement of waxy crude oil is wax deposition in oil pipelines.To ensure the safe operation of crude oil pipelines,an accurate model must be developed to predict the rate of wax deposition in crude oil pipelines.Aiming at the shortcomings of the ENN prediction model,which easily falls into the local minimum value and weak generalization ability in the implementation process,an optimized ENN prediction model based on the IRSA is proposed.The validity of the new model was confirmed by the accurate prediction of two sets of experimental data on wax deposition in crude oil pipelines.The two groups of crude oil wax deposition rate case prediction results showed that the average absolute percentage errors of IRSA-ENN prediction models is 0.5476% and 0.7831%,respectively.Additionally,it shows a higher prediction accuracy compared to the ENN prediction model.In fact,the new model established by using the IRSA to optimize ENN can optimize the initial weights and thresholds in the prediction process,which can overcome the shortcomings of the ENN prediction model,such as weak generalization ability and tendency to fall into the local minimum value,so that it has the advantages of strong implementation and high prediction accuracy.展开更多
Inadequate strength and stability of active crude oil emulsions stabilized by conventional surfactants always lead to a limited plugging rate of plugging agents.Thus,to address this issue,the synthesis of amphiphilic ...Inadequate strength and stability of active crude oil emulsions stabilized by conventional surfactants always lead to a limited plugging rate of plugging agents.Thus,to address this issue,the synthesis of amphiphilic Janus nanosheets was effectively carried out for enhancing the system performances and subsequently characterized.Based on the outcomes of orthogonal tests,an assessment was conducted on the nanosheet and surfactant formulations to optimize the enhancement of emulsion properties.The experimental demonstration of the complex system has revealed its remarkable emulsifying capability,ability to decrease interfacial tension and improve rheological behavior at high temperature(80℃)and high salinity(35,000 ppm)conditions.Involving probable mechanism of the system performance enhancement is elucidated by considering the synergistic effect between surfactants and nanosheets.Furthermore,variables including water-to-oil ratio,salinity,temperature and stirring intensity during operation,which affect the properties of prepared emulsions,were investigated in detail.The efficacy and stability of the complex system in obstructing medium and high permeability cores were demonstrated.Notably,the core with a high permeability of 913.58 mD exhibited a plugging rate of 98.55%.This study establishes the foundations of medium and high permeability reservoirs plugging with novel active crude oil plugging agents in severe environments.展开更多
With the advancement of oilfield extraction technology,since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall,increasing the difficulty of crude oil extraction.In this paper,the mesosco...With the advancement of oilfield extraction technology,since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall,increasing the difficulty of crude oil extraction.In this paper,the mesoscopic dissipative particle dynamics method is used to study themechanism of the crystallization and deposition adsorbed on thewall.The results show that in the absence of water molecules,the paraffin molecules near the substrate are deposited on themetallic surface with a horizontalmorphology,while the paraffin molecules close to the fluid side are arranged in a vertical column morphology.In the emulsified system,more water molecules will be absorbed on the metallic substrate than paraffin molecules,which obstructed the direct interaction between paraffin molecules and solid surface.Therefore,the addition of watermolecules hinders the crystallization of wax near the substrate.Perversely,on the fluid side,water molecules promote the formation of paraffin crystallization.The research in this paper reveals the crystallization mechanism of paraffin wax in oil-water emulsions in the pipeline from the microscopic scale,which provides theoretical support for improving the recovery of wax-containing crude oil and enhancing the transport efficiency.展开更多
Soil contamination by hydrocarbons poses numerous environmental, health and agricultural problems. The degradation of these pollutants can occur naturally but very slowly. It is therefore generally necessary to stimul...Soil contamination by hydrocarbons poses numerous environmental, health and agricultural problems. The degradation of these pollutants can occur naturally but very slowly. It is therefore generally necessary to stimulate this degradation by different means. Thus, this study aimed to improve the bio-degradation of diesel and crude oil in a Ghanaian soil by biostimulation. For this, the sampled soil was characterized by standard methods and contaminated with diesel and crude oil at a proportion of 1% (w/w). Then, contaminated soil samples were supplemented with biochar-compost, poultry manure or cow dung at the proportion of 10% (w/w). Periodically, fractions of these samples were taken to evaluate the density of hydrocarbon utilizing bacteria (HUB) and the residual quantities of diesel or crude oil. The characteristics of the soil used show the need for supplementation for better degradation of hydrocarbons. The results of the study show that supplementing the soil with organic substrates increases HUB loads in soils contaminated by diesel and crude oil. They also show that the residual quantities of diesel and crude oil are generally significantly lower in supplemented soils (p = 0.048 and p < 0.0001 respectively). In addition, the study shows that degradation was generally greater in soils contaminated by diesel compared to those contaminated by crude oil, especially at the end of the study.展开更多
Generically, SCM may be said to include all activities carried out to ensure proper functioning of the supply chain. The activities included in proper management of a supply chain broadly include logistics activities,...Generically, SCM may be said to include all activities carried out to ensure proper functioning of the supply chain. The activities included in proper management of a supply chain broadly include logistics activities, planning and control of the flow of information and materials in a firm, management of relationships with other organizations and government intervention, However, crude oil theft and pipeline vandalism are established products supply chain disruptors in Nigeria which are rendering the task of running an efficient petroleum supply chain onerous. This paper aims to establish the importance of effective supply chain strategies for companies in the oil and gas industry with special focus on the Nigerian oil and gas sector and the strategies by which the state oil and gas corporation in this sector may mitigate disruptions to its supply chain. This study investigates the enhancement of supply chain strategies towards meeting the challenge of crude oil theft and pipeline vandalism, using the Nigerian National Corporation (NNPC) as a case study. Based on this study, data were collected from two sources: A summary of incident reports obtained from NNPC and an interview with personnel in the PPMC Department. Incident report refers to a report produced when accidents such as equipment failure, injury, loss of life, or fire occur at the work site. Content analysis is utilized to evaluate data obtained from interview responses, CBN financial stability reports, NDIC annual reports, circulars, banking supervision reports and implementation guidelines. The study found out that NNPC should endeavor to sustain its value chain and ward of pipeline vandals and crude oil thieves by engaging in community partnership, detailing security outfits to ensure its pipelines’ right of way and bridging. Concluded that the oil supply chain of the Nigerian National Petroleum Corporation has been plagued by disruptions in the form of crude oil theft and pipeline vandalism which has had debilitating effects on its value.展开更多
The study investigated the intervention of caffeine on the effect of Nigerian Bonnylight crude oil (NBLCO) on sperm motility and morphology of diabetic Wistar rats. Eighty adult male rats (180 - 200 g body weight) wer...The study investigated the intervention of caffeine on the effect of Nigerian Bonnylight crude oil (NBLCO) on sperm motility and morphology of diabetic Wistar rats. Eighty adult male rats (180 - 200 g body weight) were randomly divided into eight groups of 10 animals each. The control group received 3 mL/Kg body weight of distilled water, ND Caf. group received 20 mL/kg body weight of caffeine, NDCO group received 3 mL/Kg body weight of NBLCO, ND Caf. + CO group received 20 and 3 mL/Kg body weight of caffeine and NBLCO respectively, diabetic group received 3 mL/Kg body weight of distilled water, D Caf. group received 20 mL/Kg body weight of caffeine, D CO received 3 mL/Kg body weight of NBLCO and D Caf. + CO group received 20 and 3 mL/Kg body weight of caffeine and NBLCO respectively, by oral gavaging for 28 days. The results showed that independent administration of caffeine and NBLCO to both non-diabetic and diabetic rats significantly (p < 0.05) altered sperm concentration, morphology and motility. Administration of NBLCO aggravated the worsening condition by significantly (p < 0.05) reducing sperm concentration, motility and increasing abnormal sperms in diabetic rats. Although caffeine significantly (p < 0.05) reduced motility in non-diabetic rats, it did cause any significant alteration in diabetic rats. Diabetes mellitus and NBLCO significantly (p < 0.05) reduced all indices that promote sperm motility while significantly (p < 0.05) increasing indices that do not promote motility. It can be concluded that diabetes mellitus and NBLCO administration have shown the tendency to promote male infertility by reducing sperm motility and adversely altering the morphology of sperm in male Wistar rats, which was ameliorated by caffeine intervention.展开更多
The use of constructed wetlands(CWs)is one of the best options to treat wastewater.In CWs,microorganisms play a major role in the degradation of organic pollutants but the concentration of nutrients,surfactant,and aer...The use of constructed wetlands(CWs)is one of the best options to treat wastewater.In CWs,microorganisms play a major role in the degradation of organic pollutants but the concentration of nutrients,surfactant,and aeration(NSA)in oil-contaminated water is one of the factors that affect the persistence and metabolic functioning of hydrocarbon-degrading microorganisms.In the present investigation,the influence of the addition of NSA on the persistence of the augmented bacteria,copy of(alkane hydroxylase gene)alkB gene,and its expression level in the water,soil,and plants of CWs were evaluated.The CWs mesocosms were developed by the vegetation of Typha latifolia and Cyperus laevigatus and inoculated with the bacterial consortium(Pseudomonas putida TYRI39,Acinetobacter junii TYRH47,Acinetobacter sp.CYRH17,Pseudomonas sp.CYSI27,and Pseudomonas sp.TYRH42).The mesocosms were provided with nutrients(20 mg l−1 N,2.6 mg l−1 P,and 16.4 mg l−1 K)in liquid form,surfactant Tween-20(0.2%,v/v)in liquid form,and aeration(≥7.0±1 mg l−1 DO)using aeration pump.The addition of NSA in CWs enhanced the persistence and metabolic functioning of the inoculated bacteria in the water,rhizospheric soil,and plants.The maximum hydrocarbon removal(97%)was observed in the water treated by CWs having C.laevigatus,bacteria,and NSA,and it is correlated with the copy numbers of alkB and its expression level.The application of NSA in CWs not only improved bacterial persistence and catabolic gene expression but also increased plant development and hydrocarbon removal.展开更多
Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fet...Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fetida (earthworm), has emerged as a promising approach to mitigate crude oil pollution. Understanding the effectiveness of these organisms in reducing hydrocarbon levels in contaminated soil is crucial for devising sustainable remediation strategies. Objectives: This study aimed to evaluate the efficacy of Pleurotus ostreatus and Eisenia fetida in remediating crude oil-polluted soil. Specifically, it sought to assess the hydrocarbon profiles in soil treated with these organisms across varying concentrations of crude oil pollution. Method: Crude oil concentration levels ranging from 0% to 10% were applied to soil samples alongside control treatments, including soil only, soil with earthworms, and soil with mushrooms. Each treatment was replicated five times using a randomized complete block design. Standard methods were employed to determine the hydrocarbon contents of the soil. Results: The results indicated a significant increase (P Pleurotus ostreatus and Eisenia fetida exhibited noteworthy reductions in these hydrocarbon levels. At the three-month mark, mushrooms demonstrated a remarkable ability to reduce hydrocarbon content by 70% - 90% compared to the pollution treatment. In contrast, earthworms exhibited minimal potential for hydrocarbon reduction, particularly at both three and six-month intervals. For instance, TOC reduction reached a maximum of 96% with mushroom treatment and 85% with earthworm treatment at 5% crude oil pollution over six months. Conclusion: The findings highlight the effectiveness of Pleurotus ostreatus in significantly reducing hydrocarbon levels in crude oil-polluted soil compared to Eisenia fetida. Mushroom-treated soils consistently exhibited substantial reductions in TOC, TPH, TOG, PAH, and THC over the study period, suggesting their potential as a viable bioremediation agent. In contrast, while earthworms showed some capability in reducing hydrocarbon content, their effectiveness was comparatively limited. Recommendation: Based on the results, it is recommended to utilize Pleurotus ostreatus for the bioremediation of crude oil-polluted soils. Further research could explore optimizing remediation protocols involving mushroom-based treatments for enhanced efficiency. Statement of Significance: This study contributes valuable insights into the application of bioremediation techniques for mitigating crude oil contamination in soil. The demonstrated efficacy of Pleurotus ostreatus underscores its potential as a sustainable and eco-friendly solution for remediating hydrocarbon-polluted environments, offering a promising avenue for environmental restoration and conservation efforts.展开更多
The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional...The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional fractions (saturates, aromatics, resins and asphaltenes) are also isolated from the heavy crude oil. These components have been characterized by spectroscopic methods (FT-IR), namely acid number, basic nitrogen number, ultimate analysis and molecular weight measurements using vapor pressure osmometry (VPO). The ion-exchange chromatography method based on separation by a functional group induces a little change on the nature of the crudes and reasonable mass balances can be easily obtained.展开更多
We measured the water content （0.01% 0.25% w/w） in crude oil emulsions using terahertz time-domain spectroscopy （THz-TDS）. To improve the precision and range of the measurements, we used 1 and 10 mm thick quartz c...We measured the water content （0.01% 0.25% w/w） in crude oil emulsions using terahertz time-domain spectroscopy （THz-TDS）. To improve the precision and range of the measurements, we used 1 and 10 mm thick quartz cells. The experiments were performed at 20 ℃ and the THz wave was transmitted vertically to the samples and detected on the other side. The experimental results suggest linear relation for the THz absorption coefficient and the water content of the crude oil emulsions in the observed range. The linear dependence facilitates high-precision measurements of the water content of crude oil. This suggests the potential of THz-TDS in determining the water concentration in crude oil and borehole fluid identification.展开更多
Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical con...Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical conditions during the production, transportation, storage, and refining, heavier molecules can precipitate from crude oil. Thus, viscous sludge formed at the bottom of storage tanks can cause many problems including reduction of storage capacity of tank, oil contamination, corrosion, repair costs, environmental pollution, etc. The reduction of sludge viscosity can be achieved by reduction of its interfacial tension. In this study, different chemical and physical factors, influencing prepared emulsions（made of sludge, water and surfactant）, such as surfactants, solvents, temperature, pressure, and mixing conditions were investigated. Results showed that non-ionic surfactants（like bitumen emulsifier）, and solvents（such as mixed xylene, AW-400, and AW-402）, injection of additives, applying pressure, and mixing operations had a positive effect on reduction of emulsion viscosity. All experiments were carried out with sludge obtained from crude oil storage tanks at Kharg Island,Iran.展开更多
The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil a...The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil and synthetic formation water was studied by measuring interfacial tension, interfacial viscoelasticity and Zeta potential. The in？ uence of the surfactants on the stability of Gudong water-in-oil （W/O） and oil-in-water （O/W） emulsions was evaluated by separating water from the W/O emulsion and residual oil in the aqueous phase of the O/W emulsion respectively. The results showed that the two kinds of surfactants, namely anionic-nonionic composite surfactant and petroleum sulfonate, are both able to decrease the interfacial tension between the oil phase and the aqueous phase and increase the surface potential of the oil droplets dispersed in the O/W emulsion, which can enhance the stability of the W/O and O/W crude oil emulsions. Compared with petroleum sulfonate, the anionic-nonionic composite surfactant is more interfacially active and able to enhance the strength of the interfacial film between oil and water, hence enhance the stability of the W/O and O/W emulsions more effectively.展开更多
Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials. All the isolates were identified as species of Pseudomon...Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials. All the isolates were identified as species of Pseudomonas. Pseudomonas putida P 11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P. aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene. Pseudomonas putida WL2 and P. aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11. All the strains grew logarithmically with 1-2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence. Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period. BB3 on the other hand degraded only 46% within 6 d. Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks （including aliphatics and aromatics） in the hydrocarbon mixture.展开更多
Refineries often need to find similar crude oil to replace the scarce crude oil for stabilizing the feedstock property. We introduced the method for calculation of crude blended properties firstly, and then created a ...Refineries often need to find similar crude oil to replace the scarce crude oil for stabilizing the feedstock property. We introduced the method for calculation of crude blended properties firstly, and then created a crude oil selection and blending optimization model based on the data of crude oil property. The model is a mixed-integer nonlinear programming(MINLP) with constraints, and the target is to maximize the similarity between the blended crude oil and the objective crude oil. Furthermore, the model takes into account the selection of crude oils and their blending ratios simultaneously, and transforms the problem of looking for similar crude oil into the crude oil selection and blending optimization problem. We applied the Improved Cuckoo Search(ICS) algorithm to solving the model. Through the simulations, ICS was compared with the genetic algorithm, the particle swarm optimization algorithm and the CPLEX solver. The results show that ICS has very good optimization efficiency. The blending solution can provide a reference for refineries to find the similar crude oil. And the method proposed can also give some references to selection and blending optimization of other materials.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(52074089 and 52104064)Natural Science Foundation of Heilongjiang Province of China(LH2019E019).
文摘As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.
文摘The Saltpond Basin,situated within the South Atlantic margin of Ghana,is a significant area for petro-leum exploration but has received relatively limited research attention.Previous studies have examined source rock com-position,but data on crude oil organic chemistry are lack-ing,hindering understanding of the basin’s petroleum system and evolution.To address this gap,we analyzed biomarkers and stable carbon-isotope ratios in Saltpond Basin crude oil using gas chromatography–mass spectrometry and gas chromatography–isotope ratio mass spectrometry to eluci-date organic matter source,depositional environment,and thermal maturity.Findings were compared with oils from the West African segment of the South Atlantic margin,namely the Tano Basin and the Niger Delta Basin,to iden-tify potential correlations and gain insights into regional variations.Molecular and isotopic results unveiled a sig-nificant prevalence of organic matter derived from lower marine organisms.Patterns of organic matter deposition and preservation in Saltpond oil samples suggested a suboxic marine transitional environment,contradicting conventional understanding of terrestrial dominance in such settings.Moreover,the potential for degradation processes to obscure differentiation between terrestrial and marine organic mat-ter origins underscores the complex nature of organic mat-ter dynamics in transitional marine environments.Analysis of molecular thermal maturity indices suggested Saltpond oils were expelled from source rocks exhibiting thermal maturity at the early maturity stage.Correlation analysis unveiled genetic disparities among crude oils sourced from the Saltpond Basin and those from the Tano and Niger Delta Basin,primarily due to variations in source input and depo-sitional environment conditions.Saltpond oil exhibits lower terrestrial organic input than Tano Basin’s crude oils,which also have less terrestrial input than Niger Delta Basin crude oils.Additionally,its paleodepositional environment nota-bly differs from oils in the Tano Basin(anoxic transitional marine-lacustrine settings)and the Niger Delta Basin(sub-oxic–oxic terrigenous deltaic or marine or lacustrine envi-ronments).Thermal maturity range of Saltpond oil is com-parable to oils in the Tano Basin but lower than oils in the Niger Delta Basin.Thesefindings provide valuable insights into petroleum generation history and unique organic geo-chemical characteristics within the Saltpond Basin,essen-tial for exploration,production,and environmental manage-ment efforts in the region.Furthermore,correlation studies provide evidence that distinct biological,geological,and paleoenvironmental conditions shaped various oil types in the West African segment of the South Atlantic margin.
基金funded by the National Natural Science Foundation of China(No.42272160,No.41502133).
文摘The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,Chad.The results suggest that diamondoids,including adamantanes(As)and diamantanes(Ds),are relatively resistant to biodegradation and obvious biodegradation was observed in oils with a Peters-Moldowan(PM)biodegradation rank of 6 or more.Overall,the sensibility of biodegradation on diamondoids is generally similar to hopanes and regular steranes.As biodegradation evolves,the changes in concentration and components of diamondoids show that the biodegradation process is selective and stepwise.The significant increase of MD/MA and DMD/DMA for oils with a PM ranking 6^(+) indicates that diamantanes are generally more resistant to biodegradation than adamantanes.The similar trends of DMA/MA,EA/MA,MD/D,DMD/MD and other relevant indexes,show that higher alkylation homologs are more resistant to biodegradation.The commonly used diamondoid ratios,such as MAI,EAI,MDI and DMID-1,are obviously affected by biodegradation at the stage of high-level biodegradation,which may indicate that these ratios should be used with caution in case of severely degraded oils.
基金the supports from National Natural Science Foundation of China(61988101,62073142,22178103)National Natural Science Fund for Distinguished Young Scholars(61925305)International(Regional)Cooperation and Exchange Project(61720106008)。
文摘Crude oil scheduling optimization is an effective method to enhance the economic benefits of oil refining.But uncertainties,including uncertain demands of crude distillation units(CDUs),might make the production plans made by the traditional deterministic optimization models infeasible.A data-driven Wasserstein distributionally robust chance-constrained(WDRCC)optimization approach is proposed in this paper to deal with demand uncertainty in crude oil scheduling.First,a new deterministic crude oil scheduling optimization model is developed as the basis of this approach.The Wasserstein distance is then used to build ambiguity sets from historical data to describe the possible realizations of probability distributions of uncertain demands.A cross-validation method is advanced to choose suitable radii for these ambiguity sets.The deterministic model is reformulated as a WDRCC optimization model for crude oil scheduling to guarantee the demand constraints hold with a desired high probability even in the worst situation in ambiguity sets.The proposed WDRCC model is transferred into an equivalent conditional value-at-risk representation and further derived as a mixed-integer nonlinear programming counterpart.Industrial case studies from a real-world refinery are conducted to show the effectiveness of the proposed method.Out-of-sample tests demonstrate that the solution of the WDRCC model is more robust than those of the deterministic model and the chance-constrained model.
基金the Shandong Provincial Natural Science Foundation(No.ZR2019MEE038,ZR202110260011)the Fundamental Research Funds for the Central Universities(No.19CX02038A)。
文摘A total of 14 halophilic hydrocarbon-degrading strains were isolated from crude oil-contaminated sites,using petroleum as the sole carbon and energy source.Among these,four highly efficient strains were selected to create the mixed bacterial agent XH-1.These four strains were identified through 16S rRNA gene-based sequencing as belonging to Acinetobacter,Bacillus paramycoides,Rhodococcus sp.,and Enterobacter sp.,respectively.The optimal cultivation time for the mixed consortium XH-1 was found to be 48 h,and a nitrogen-phosphorus molar ratio of 10:1 was determined to be beneficial for crude oil degradation.XH-1 showed notable crude oil degradation even at a salinity of up to 30 g/L,with little inhibition observed at sulfide concentrations as high as 150 mg/L and initial oil concentrations of 500 mg/L.Gas chromatography analysis revealed that XH-1 was able to efficiently degrade C9–C29 n-alkanes.Moreover,a bio-contact oxidation reactor enhanced by XH-1 showed promising results in treating oilfield wastewater.These findings suggest that XH-1 can be applied for the treatment of oilfield wastewater.
文摘Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.
文摘A hard problem that hinders the movement of waxy crude oil is wax deposition in oil pipelines.To ensure the safe operation of crude oil pipelines,an accurate model must be developed to predict the rate of wax deposition in crude oil pipelines.Aiming at the shortcomings of the ENN prediction model,which easily falls into the local minimum value and weak generalization ability in the implementation process,an optimized ENN prediction model based on the IRSA is proposed.The validity of the new model was confirmed by the accurate prediction of two sets of experimental data on wax deposition in crude oil pipelines.The two groups of crude oil wax deposition rate case prediction results showed that the average absolute percentage errors of IRSA-ENN prediction models is 0.5476% and 0.7831%,respectively.Additionally,it shows a higher prediction accuracy compared to the ENN prediction model.In fact,the new model established by using the IRSA to optimize ENN can optimize the initial weights and thresholds in the prediction process,which can overcome the shortcomings of the ENN prediction model,such as weak generalization ability and tendency to fall into the local minimum value,so that it has the advantages of strong implementation and high prediction accuracy.
基金financially supported by National Natural Science Foundation of China(52374053)Beijing Natural Science Foundation(2204092)Beijing Municipal Excellent Talent Training Funds Youth Advanced Individual Project(2018000020124G163)。
文摘Inadequate strength and stability of active crude oil emulsions stabilized by conventional surfactants always lead to a limited plugging rate of plugging agents.Thus,to address this issue,the synthesis of amphiphilic Janus nanosheets was effectively carried out for enhancing the system performances and subsequently characterized.Based on the outcomes of orthogonal tests,an assessment was conducted on the nanosheet and surfactant formulations to optimize the enhancement of emulsion properties.The experimental demonstration of the complex system has revealed its remarkable emulsifying capability,ability to decrease interfacial tension and improve rheological behavior at high temperature(80℃)and high salinity(35,000 ppm)conditions.Involving probable mechanism of the system performance enhancement is elucidated by considering the synergistic effect between surfactants and nanosheets.Furthermore,variables including water-to-oil ratio,salinity,temperature and stirring intensity during operation,which affect the properties of prepared emulsions,were investigated in detail.The efficacy and stability of the complex system in obstructing medium and high permeability cores were demonstrated.Notably,the core with a high permeability of 913.58 mD exhibited a plugging rate of 98.55%.This study establishes the foundations of medium and high permeability reservoirs plugging with novel active crude oil plugging agents in severe environments.
基金sponsored by Natural Science Foundation of Xinjiang Uygur Autonomous Region,Grant No.2023D01C197Performance Incentive Guidance Project of Chongqing Scientific Research Institutions(cstc2022jxjl20016).
文摘With the advancement of oilfield extraction technology,since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall,increasing the difficulty of crude oil extraction.In this paper,the mesoscopic dissipative particle dynamics method is used to study themechanism of the crystallization and deposition adsorbed on thewall.The results show that in the absence of water molecules,the paraffin molecules near the substrate are deposited on themetallic surface with a horizontalmorphology,while the paraffin molecules close to the fluid side are arranged in a vertical column morphology.In the emulsified system,more water molecules will be absorbed on the metallic substrate than paraffin molecules,which obstructed the direct interaction between paraffin molecules and solid surface.Therefore,the addition of watermolecules hinders the crystallization of wax near the substrate.Perversely,on the fluid side,water molecules promote the formation of paraffin crystallization.The research in this paper reveals the crystallization mechanism of paraffin wax in oil-water emulsions in the pipeline from the microscopic scale,which provides theoretical support for improving the recovery of wax-containing crude oil and enhancing the transport efficiency.
文摘Soil contamination by hydrocarbons poses numerous environmental, health and agricultural problems. The degradation of these pollutants can occur naturally but very slowly. It is therefore generally necessary to stimulate this degradation by different means. Thus, this study aimed to improve the bio-degradation of diesel and crude oil in a Ghanaian soil by biostimulation. For this, the sampled soil was characterized by standard methods and contaminated with diesel and crude oil at a proportion of 1% (w/w). Then, contaminated soil samples were supplemented with biochar-compost, poultry manure or cow dung at the proportion of 10% (w/w). Periodically, fractions of these samples were taken to evaluate the density of hydrocarbon utilizing bacteria (HUB) and the residual quantities of diesel or crude oil. The characteristics of the soil used show the need for supplementation for better degradation of hydrocarbons. The results of the study show that supplementing the soil with organic substrates increases HUB loads in soils contaminated by diesel and crude oil. They also show that the residual quantities of diesel and crude oil are generally significantly lower in supplemented soils (p = 0.048 and p < 0.0001 respectively). In addition, the study shows that degradation was generally greater in soils contaminated by diesel compared to those contaminated by crude oil, especially at the end of the study.
文摘Generically, SCM may be said to include all activities carried out to ensure proper functioning of the supply chain. The activities included in proper management of a supply chain broadly include logistics activities, planning and control of the flow of information and materials in a firm, management of relationships with other organizations and government intervention, However, crude oil theft and pipeline vandalism are established products supply chain disruptors in Nigeria which are rendering the task of running an efficient petroleum supply chain onerous. This paper aims to establish the importance of effective supply chain strategies for companies in the oil and gas industry with special focus on the Nigerian oil and gas sector and the strategies by which the state oil and gas corporation in this sector may mitigate disruptions to its supply chain. This study investigates the enhancement of supply chain strategies towards meeting the challenge of crude oil theft and pipeline vandalism, using the Nigerian National Corporation (NNPC) as a case study. Based on this study, data were collected from two sources: A summary of incident reports obtained from NNPC and an interview with personnel in the PPMC Department. Incident report refers to a report produced when accidents such as equipment failure, injury, loss of life, or fire occur at the work site. Content analysis is utilized to evaluate data obtained from interview responses, CBN financial stability reports, NDIC annual reports, circulars, banking supervision reports and implementation guidelines. The study found out that NNPC should endeavor to sustain its value chain and ward of pipeline vandals and crude oil thieves by engaging in community partnership, detailing security outfits to ensure its pipelines’ right of way and bridging. Concluded that the oil supply chain of the Nigerian National Petroleum Corporation has been plagued by disruptions in the form of crude oil theft and pipeline vandalism which has had debilitating effects on its value.
文摘The study investigated the intervention of caffeine on the effect of Nigerian Bonnylight crude oil (NBLCO) on sperm motility and morphology of diabetic Wistar rats. Eighty adult male rats (180 - 200 g body weight) were randomly divided into eight groups of 10 animals each. The control group received 3 mL/Kg body weight of distilled water, ND Caf. group received 20 mL/kg body weight of caffeine, NDCO group received 3 mL/Kg body weight of NBLCO, ND Caf. + CO group received 20 and 3 mL/Kg body weight of caffeine and NBLCO respectively, diabetic group received 3 mL/Kg body weight of distilled water, D Caf. group received 20 mL/Kg body weight of caffeine, D CO received 3 mL/Kg body weight of NBLCO and D Caf. + CO group received 20 and 3 mL/Kg body weight of caffeine and NBLCO respectively, by oral gavaging for 28 days. The results showed that independent administration of caffeine and NBLCO to both non-diabetic and diabetic rats significantly (p < 0.05) altered sperm concentration, morphology and motility. Administration of NBLCO aggravated the worsening condition by significantly (p < 0.05) reducing sperm concentration, motility and increasing abnormal sperms in diabetic rats. Although caffeine significantly (p < 0.05) reduced motility in non-diabetic rats, it did cause any significant alteration in diabetic rats. Diabetes mellitus and NBLCO significantly (p < 0.05) reduced all indices that promote sperm motility while significantly (p < 0.05) increasing indices that do not promote motility. It can be concluded that diabetes mellitus and NBLCO administration have shown the tendency to promote male infertility by reducing sperm motility and adversely altering the morphology of sperm in male Wistar rats, which was ameliorated by caffeine intervention.
基金the Researchers Supporting Project number(RSP2024R437)King Saud University,Riyadh,Saudi ArabiaThe authors are thankful to the Higher Education Commission(HEC)for the grant of IRSIP Fellowship to the lead author for research at Aarhus University Denmark and ALP Pakistan Agriculture Research Council(PARC)grant No.NR-086.
文摘The use of constructed wetlands(CWs)is one of the best options to treat wastewater.In CWs,microorganisms play a major role in the degradation of organic pollutants but the concentration of nutrients,surfactant,and aeration(NSA)in oil-contaminated water is one of the factors that affect the persistence and metabolic functioning of hydrocarbon-degrading microorganisms.In the present investigation,the influence of the addition of NSA on the persistence of the augmented bacteria,copy of(alkane hydroxylase gene)alkB gene,and its expression level in the water,soil,and plants of CWs were evaluated.The CWs mesocosms were developed by the vegetation of Typha latifolia and Cyperus laevigatus and inoculated with the bacterial consortium(Pseudomonas putida TYRI39,Acinetobacter junii TYRH47,Acinetobacter sp.CYRH17,Pseudomonas sp.CYSI27,and Pseudomonas sp.TYRH42).The mesocosms were provided with nutrients(20 mg l−1 N,2.6 mg l−1 P,and 16.4 mg l−1 K)in liquid form,surfactant Tween-20(0.2%,v/v)in liquid form,and aeration(≥7.0±1 mg l−1 DO)using aeration pump.The addition of NSA in CWs enhanced the persistence and metabolic functioning of the inoculated bacteria in the water,rhizospheric soil,and plants.The maximum hydrocarbon removal(97%)was observed in the water treated by CWs having C.laevigatus,bacteria,and NSA,and it is correlated with the copy numbers of alkB and its expression level.The application of NSA in CWs not only improved bacterial persistence and catabolic gene expression but also increased plant development and hydrocarbon removal.
文摘Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fetida (earthworm), has emerged as a promising approach to mitigate crude oil pollution. Understanding the effectiveness of these organisms in reducing hydrocarbon levels in contaminated soil is crucial for devising sustainable remediation strategies. Objectives: This study aimed to evaluate the efficacy of Pleurotus ostreatus and Eisenia fetida in remediating crude oil-polluted soil. Specifically, it sought to assess the hydrocarbon profiles in soil treated with these organisms across varying concentrations of crude oil pollution. Method: Crude oil concentration levels ranging from 0% to 10% were applied to soil samples alongside control treatments, including soil only, soil with earthworms, and soil with mushrooms. Each treatment was replicated five times using a randomized complete block design. Standard methods were employed to determine the hydrocarbon contents of the soil. Results: The results indicated a significant increase (P Pleurotus ostreatus and Eisenia fetida exhibited noteworthy reductions in these hydrocarbon levels. At the three-month mark, mushrooms demonstrated a remarkable ability to reduce hydrocarbon content by 70% - 90% compared to the pollution treatment. In contrast, earthworms exhibited minimal potential for hydrocarbon reduction, particularly at both three and six-month intervals. For instance, TOC reduction reached a maximum of 96% with mushroom treatment and 85% with earthworm treatment at 5% crude oil pollution over six months. Conclusion: The findings highlight the effectiveness of Pleurotus ostreatus in significantly reducing hydrocarbon levels in crude oil-polluted soil compared to Eisenia fetida. Mushroom-treated soils consistently exhibited substantial reductions in TOC, TPH, TOG, PAH, and THC over the study period, suggesting their potential as a viable bioremediation agent. In contrast, while earthworms showed some capability in reducing hydrocarbon content, their effectiveness was comparatively limited. Recommendation: Based on the results, it is recommended to utilize Pleurotus ostreatus for the bioremediation of crude oil-polluted soils. Further research could explore optimizing remediation protocols involving mushroom-based treatments for enhanced efficiency. Statement of Significance: This study contributes valuable insights into the application of bioremediation techniques for mitigating crude oil contamination in soil. The demonstrated efficacy of Pleurotus ostreatus underscores its potential as a sustainable and eco-friendly solution for remediating hydrocarbon-polluted environments, offering a promising avenue for environmental restoration and conservation efforts.
文摘The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional fractions (saturates, aromatics, resins and asphaltenes) are also isolated from the heavy crude oil. These components have been characterized by spectroscopic methods (FT-IR), namely acid number, basic nitrogen number, ultimate analysis and molecular weight measurements using vapor pressure osmometry (VPO). The ion-exchange chromatography method based on separation by a functional group induces a little change on the nature of the crudes and reasonable mass balances can be easily obtained.
基金sponsored jointly by the National Key Basic Research Program of China(No.2013CB328706)the Special-funded Program on National Key Scientific Instruments and Equipment Development(No.2012YQ140005)+1 种基金the Beijing National Science Foundation(No.4122064)the Science Foundation of China University of Petroleum(Beijing)(No.QZDX-2010-01 and KYJJ2012-06-27)
文摘We measured the water content （0.01% 0.25% w/w） in crude oil emulsions using terahertz time-domain spectroscopy （THz-TDS）. To improve the precision and range of the measurements, we used 1 and 10 mm thick quartz cells. The experiments were performed at 20 ℃ and the THz wave was transmitted vertically to the samples and detected on the other side. The experimental results suggest linear relation for the THz absorption coefficient and the water content of the crude oil emulsions in the observed range. The linear dependence facilitates high-precision measurements of the water content of crude oil. This suggests the potential of THz-TDS in determining the water concentration in crude oil and borehole fluid identification.
文摘Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical conditions during the production, transportation, storage, and refining, heavier molecules can precipitate from crude oil. Thus, viscous sludge formed at the bottom of storage tanks can cause many problems including reduction of storage capacity of tank, oil contamination, corrosion, repair costs, environmental pollution, etc. The reduction of sludge viscosity can be achieved by reduction of its interfacial tension. In this study, different chemical and physical factors, influencing prepared emulsions（made of sludge, water and surfactant）, such as surfactants, solvents, temperature, pressure, and mixing conditions were investigated. Results showed that non-ionic surfactants（like bitumen emulsifier）, and solvents（such as mixed xylene, AW-400, and AW-402）, injection of additives, applying pressure, and mixing operations had a positive effect on reduction of emulsion viscosity. All experiments were carried out with sludge obtained from crude oil storage tanks at Kharg Island,Iran.
基金supported by the National Key Scientific and Technological Projects (2008ZX05011)
文摘The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil and synthetic formation water was studied by measuring interfacial tension, interfacial viscoelasticity and Zeta potential. The in？ uence of the surfactants on the stability of Gudong water-in-oil （W/O） and oil-in-water （O/W） emulsions was evaluated by separating water from the W/O emulsion and residual oil in the aqueous phase of the O/W emulsion respectively. The results showed that the two kinds of surfactants, namely anionic-nonionic composite surfactant and petroleum sulfonate, are both able to decrease the interfacial tension between the oil phase and the aqueous phase and increase the surface potential of the oil droplets dispersed in the O/W emulsion, which can enhance the stability of the W/O and O/W crude oil emulsions. Compared with petroleum sulfonate, the anionic-nonionic composite surfactant is more interfacially active and able to enhance the strength of the interfacial film between oil and water, hence enhance the stability of the W/O and O/W emulsions more effectively.
文摘Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials. All the isolates were identified as species of Pseudomonas. Pseudomonas putida P 11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P. aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene. Pseudomonas putida WL2 and P. aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11. All the strains grew logarithmically with 1-2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence. Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period. BB3 on the other hand degraded only 46% within 6 d. Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks （including aliphatics and aromatics） in the hydrocarbon mixture.
基金supported by the National Natural Science Foundation of China(No.21365008)the Science Foundation of Guangxi province of China(No.2012GXNSFAA053230)
文摘Refineries often need to find similar crude oil to replace the scarce crude oil for stabilizing the feedstock property. We introduced the method for calculation of crude blended properties firstly, and then created a crude oil selection and blending optimization model based on the data of crude oil property. The model is a mixed-integer nonlinear programming(MINLP) with constraints, and the target is to maximize the similarity between the blended crude oil and the objective crude oil. Furthermore, the model takes into account the selection of crude oils and their blending ratios simultaneously, and transforms the problem of looking for similar crude oil into the crude oil selection and blending optimization problem. We applied the Improved Cuckoo Search(ICS) algorithm to solving the model. Through the simulations, ICS was compared with the genetic algorithm, the particle swarm optimization algorithm and the CPLEX solver. The results show that ICS has very good optimization efficiency. The blending solution can provide a reference for refineries to find the similar crude oil. And the method proposed can also give some references to selection and blending optimization of other materials.
