This article conducts research on the injection production well patterns under different injection production conditions through two methods: physical simulation and numerical simulation. On the core scale, a reservoir physical simulation model was prepared based on similarity criteria. It was found that the higher the permeability of the physical model was, the lower the overall pressure value was and the smaller the average pressure drop after shutdown. As the viscosity of crude oil increases, the overall pressure of the model increases, and the reduction in pressure during adjustment becomes more pronounced. As the decrease in flow rate increases, the decrease in pressure regulation significantly increases. According to the numerical simulation results, due to the obstruction of the fault, there is no connectivity on both sides, resulting in different energy replenishment on both sides. As the mining progresses, the pressure difference decreases from 0.35 MPa in the initial stage to around 0.15 MPa.When both sides of the fault of the adjustment well are one injection and two extractions, the pressure difference between the two sides of the fault exists with the extension of the development time, but converges again in the late production period.While both sides of the fault of the adjustment well are one injection and two extractions and one injection and four extractions, the difference between the two sides of the fault pressure system increases with the extension of the development time. The research of this paper is of great significance to drilling of adjustment wells in the "Double High" oilfield.
Rising levels of nitrate and nitrogen in water bodies pose a potential threat to aquatic ecosystems and human health. Therefore, it is urgent to solve the problem of excessive nitrate in water bodies. Fe(NO3)3·9H2O, Co(NO3)2·6H2O, reed biochar, NH3·H2O was used as raw material, and co?precipitation method was used to load cobalt?iron layered bimetals onto reed biochar to prepare Co/Fe?LDH@BC for adsorption of excess nitrate nitrogen in water. The experimental results showed that Co/Fe?LDH@BC could effectively adsorb nitrate nitrogen in water, and its adsorption capacity was 88.52 mg/g. The adsorption kinetic model conforms to the pseudo?second?order kinetic model, and the isotherm conforms to the Langmuir isotherm model, indicating that the adsorption reaction is spontaneous and endothermic, which mainly involves four reaction mechanisms: ion exchange, ligand exchange, electrostatic attraction and hydrogen bonding. In addition, Co/Fe?LDH@BC has a strong affinity for nitrate nitrogen in most water bodies where coexisting anions are present, making it suitable for practical applications.
Aromaticity is one of the important chemical properties of aromatic compounds. Clarifying the aromaticity of a clearly ring?conjugated system is crucial for understanding the chemical reactivity and stability of the system. A detailed study of the aromaticity, one?photon absorption (OPA), two?photon absorption (TPA) spectra, and electron transfer properties of Kekulene was carried out through quantum chemical calculations and wave function analysis. The aromaticity of different benzene rings in the molecule was quantitatively analyzed through multicenter bond indices and AV1245 indices. The aromaticity of Kekulene was studied through various methods such as electron localization function (ELF), localized orbital locator (LOL), magnetic susceptibility current, and isotropic chemical shielding surface (ICSS). The electron transfer processes of OPA and TPA transitions were visualized through charge difference density (CDD) analysis. The results showed that the aromaticity of rings 1 and 2 was significantly stronger than that of rings 3 and 4. The π electrons of ELF and LOL can be highly delocalized on both sides of the first ring and form a loop. The OPA spectrum has excited states with higher transition dipole moments, which are more likely to become intermediate states in the TPA process. The research results can provide effective theoretical methods and application approaches for the aromaticity of different systems.
Anthraquinone dyes are the second most significant dyes in the dye industry after azo dyes.Nitroanthraquinone prepared by the nitration of anthraquinone,is one of the important raw materials for the synthesis of various types of anthraquinone dyes.In this study,a microreactor with excellent heat and mass transfer properties was utilized to investigate the continuous?flow nitration process of anthraquinone.The effects of key process parameters such as reaction temperature,volume flow rate,molar ratio of nitric acid to anthraquinone,anthraquinone concentration,residence time,and sulfuric acid intensity on the nitration process were examined.The results showed that the competition between mono? and di?nitrification reactions during anthraquinone nitrification was significant, and the adjustment of process parameters would significantly affect the ratio of mono? and di?nitrification products while promoting the conversion rate of anthraquinone.The full use of the advantages of microreactors to precisely regulate the process parameters is an effective measure to improve the selectivity of the target nitration product.
Plastics are synthetic or natural polymers that are widely used in industrial fields and daily life due to its good durability and plasticity.Among plastics,polyethylene terephthalate (PET) is the most commonly used.Polyethylene terephthalate (PET) is one of the commonly used plastics,which is widely used in many fields.PET is difficult to be degraded under natural circumstances without artificial treatment,which brings serious burden to the ecosystems,so the issue of degradation and regeneration of PET plastics has become a hot issue globally.Many methods such as photodegradation,thermal degradation,biodegradation,etc.,have been developed to degrade plastics.Among them,biodegradation is considered as environmental friendly and highly efficient method.Thus,the design and transformation of PET degradation has become a key issue.The main methods for degrading plastics at the present stage,the common enzymes used for degrading PET by biodegradation methods and the modification methods of PET degrading enzymes are reviewed,to provide a theoretical basis for the rapid degradation and regeneration of PET.
Aiming at the problems of slow generation rate,low storage capacity and harsh generation conditions of CO2 during the hydrate generation process,bimetallic Cu and Al?loaded graphene oxide materials were used as additives for the kinetic characterisation of CO2 hydrate generation.Firstly,the prepared GO?Cu?Al material was characterized by TEM,EDS,XPS,and stability analysis.Secondly,experiments were conducted on the kinetics of CO2 hydrate formation under 274.15 K and 3.0 MPa.The effects of different additive concentrations on the induction time,reaction time, gas consumption,and gas storage capacity of CO2 hydrate formation were analyzed,and a comparison was made between monometallic and bimetallic supported materials.The results show that bimetallic Cu and Al can be uniformly loaded onto graphene oxide with good stability.At 274.15 K,3.0 MPa,and a concentration of 50 μ g / g ,the induction time of CO2 hydrate is 85 min, the reaction time is 170 min, the gas consumption is 0.216 mol,and the gas storage capacity is 123.81 cm3/cm3.Compared with pure water system,the induction time and reaction time are shortened by about 1 / 4 and 1 / 7 respectively,and the gas consumption and storage capacity are correspondingly improved.Compared with the monometallic loading system，the maximum induction time is shortened by about 1 / 2 , the maximum reaction time is shortened by about 1 / 5 , and the gas storage capacity is significantly improved.
With the rise of electric revolution and the establishment of "carbon dioxide emission and carbon neutrality" strategy, petroleum coke has got great development in value?added applications such as lithium cathode materials and high?grade prebaked anode.However,high value?added applications of petroleum coke all have strict requirements for sulfur content of petroleum coke. The high sulfur content in petroleum coke will have a negative impact on the high value application of petroleum coke.The research status of main desulphurization technologies of petroleum coke,including solvent extraction desulfurization technology,high temperature calcination desulfurization technology,oxidation desulfurization technology, alkali metal compound desulfurization technology,hydrodesulfurization technology,microbial desulfurization technology and process intensification auxiliary desulfurization technology are summarized.It was found that the desulphurisation rate of process?enhanced assisted desulphurisation could reach 93.6%,which could reduce the sulphur mass fraction in petroleum coke from 7.57% to 0.48%. The desulfurization technology of petroleum coke should maintain the principle that the structure of petroleum coke after desulfurization is not destroyed to the greatest extent.Therefore,oxidative desulfurization coupled process enhancement assisted desulfurization should have bright prospect in industrial application of petroleum coke desulphurization.
Paraffin is mainly composed of n?alkanes, small amounts of i?alkanes, cycloalkanes, aromatic hydrocarbons and trace amounts of S,N,O compounds. Under the action of ultraviolet light and heat, those compounds containing elements S,N,O,aromatic and unstable elements of alkene aromatic can be oxidated,resulting in a darker color and lower paraffin light stability.In order to explore the reasons for the deterioration of the paraffin light stability,the effects of internal factors such as nitrates,sulfides and oil content on the paraffin light stability were investigated.Orthogonal experiments were carried out to investigate the effects of ultraviolet absorbers,hindered amine light stabilizers,antioxidants and its compounding agent on the improvement of the paraffin light stability.The results showed that the best paraffin light stability was achieved when the additive amounts of UV absorbers, hindered amine light stabilizers and antioxidants in the compound were 300 μg/g, 300 μg/g and 300 μg/g, respectively.
Using artificial simulation of diesel contaminated soil, the degradation and remediation ability of functional microbial communities on diesel contaminated soil, as well as changes in microbial diversity and microbial structure composition, were studied. The experimental results of microbial community degradation of diesel in soil showed that after 30 days of degradation, the final degradation rate of microbial community on diesel pollution in soil reached 74.3%.The respiratory intensity of the microbial community in the soil gradually increases within 30 days. When the soil depth changes, the degradation ability of the microbial community gradually weakens with the increase of depth. The results of high throughput sequencing showed that after 30 days of degradation, the microbial diversity and richness in the soil increased compared with the initial degradation, indicating that the microbial community could adapt to the diesel pollution environment well. The initial microbial community for diesel degradation is mainly composed of Proteobacteria, Firmicutes, and a small amount of Bctoidetes. After 30 days of cultivation, the main dominant bacteria in the surface soil are Proteobacteria, while the main dominant bacteria in the deep soil are Firmicutes. Studying the remediation of diesel?contaminated soil by microbial communities and changes in microbial structure and diversity, technical support can be provided for the remediation of diesel?contaminated soil.
The traditional method for determining the oil content of oily sludge was improved, and the extraction smartphone image colorimetry was established by combining the image colorimetry with the pretreatment method of hot solvent extraction. The effects of RGB value, different color channels, shutter time, sensitivity, white balance and other parameters on the determination of oil content were investigated. Under the premise that the light source was tungsten iodide lamp and the front camera of Samsung A8s mobile phone was used, the best test conditions were finally determined: white balance value was 2 800 K, sensitivity value was 100, shutter time was 1 / 2 000 s. The linear correlation coefficients of the method under the optimal test conditions were more than 0.99 under the optimal test conditions, and the linear range was similar to that of the spectrophotometric method, with the detection limit of 0.06% and the lower limit of 0.24%. The recoveries of 8 groups of parallel standard samples were 96%~103%, and the relative standard deviation was 2.26%, which indicated that the accuracy of this method was relatively high. Compared with the traditional method, this method is more simple and rapid, and its accuracy can meet the needs of conventional oil content measurement, which is expected to realise the rapid on?site determination of oil content of large?scale oil?containing sludge in plants.
In order to investigate the synergistic catalytic aquathermolysis after external catalyst entering the reservoir and complexation with in?situ inorganic minerals,a simulated internal and external synergistic catalyst of montmorillonite?supported zinc citrate complex was prepared,and its catalytic viscosity reduction performance for heavy oil was investigated.The heavy oil before and after the reaction was analyzed by thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),gas chromatography(GC) and elemental analysis(EA).The results showed that the composite catalyst B@Zn(Ⅱ)L increased the viscosity reduction rate of heavy oil from 55.2% to 65.4% at 30 ℃,which confirmed the phenomenon of internal and external source synergistic catalysis in heavy oil thermal recovery.After synergizing the composite catalyst B@Zn(Ⅱ)L with the hydrogen supply agent ethanol,the viscosity reduction rate of heavy oil increased from 65.4% to 80.1%.After the reaction of heavy oil, some of the high hydrocarbon compounds in the heavy oil were cracked into low hydrocarbon compounds after the reaction,and some heavy components were decomposed into light components.Therefore, the wax precipitation point of heavy oil decreased,the mass fraction of N and S decreased,the content of high hydrocarbons decreased,and the content of low carbon hydrocarbons increased.
This paper studies the stability of crude oil emulsion characterized by conductivity difference between upper and lower layers. According to the changes of conductivity in the upper and lower layers of crude oil emulsion system, combined with optical microscope observation, the methods and conditions to characterize the stability of crude oil emulsion can be studied by the difference of conductivity between the upper and lower layers. Research finds that when the crude oil system is demulsified and phase separated, the composition, morphology and conductivity of the upper and lower emulsions will be different.Therefore, the conductivity difference between the upper and lower emulsions can be used as the characterization parameter of emulsion stability. By measuring the conductivity and the difference values of the upper and lower layers of the system at different electrical test signal frequencies (0.1,1.0,10.0,100.0 kHz), it is found that the conductivity values and the difference values at high frequency are greater than those at low frequency, and the sensitivity is higher. In addition,when the conductivity difference is greater than 15%, the system is unstable. The experimental results show that the method is also suitable for emulsion system containing anionic surfactant.
During the injection process, micro?nano bubbles are generated in the oil?displacing agent polyacrylamide (HPAM) system. This will lead to the oxidative degradation of HPAM and the loss of viscosity. In order to determine the effect of micro?nano bubbles on the change rule of the viscosity retention rate and structure of HPAM solution, the viscosity retention rate at different aeration conditions was studied, and technologies such as dynamic laser scattering, biological microscopy, and infrared spectroscopy were carried out. Results showed that the viscosity retention rate of HPAM sample, which was prepared with simulated mineralized water after 20 mins circulation of the micro?nano bubbles generator with air as the gas source, decreases the most, and its viscosity average molecular weight is also the lowest. This is attributed to the chemical reaction between oxygen and HPAM molecules in the solution, leading to oxidative degradation. The micro?nano bubbles containing air increase the solubility of oxygen in the solution and generate hydroxyl radicals (·OH), thereby reducing the viscosity retention. In the absence of inflation, micro?nano bubbles are formed in the HPAM solution during the preparation process due to mechanical shear, but the high concentration of the solution hinders the dispersion of micro?nano bubbles, thereby slowing down the decrease in viscosity retention. In addition, micro?nano bubbles have a longer stabilization time in solution than large bubbles, and will affect the particle size distribution of the polymer, resulting in uneven particle size distribution and larger average particle size.
In the process of hydrogen storage by MOFs materials, the low thermal conductivity of the materials leads to heat accumulation,which affects the hydrogen storage performance.In order to improve the thermal conductivity of the adsorbent material and take into account its hydrogen storage capacity, numerical simulation was used to analyze the optimal regulation range of the thermal conductivity of the adsorbent material.The results show that when the thermal conductivity of the adsorbent material is in the range of 0~1.2 W/(m·K), the maximum temperature, average temperature and hydrogen absorption capacity of the hydrogen storage tank are obviously improved with the increase of thermal conductivity.When the thermal conductivity of the material is greater than 1.2 W/(m·K), the improvement effect is significantly weakened; when the material thermal conductivity is greater than 2.0 W/(m·K), the improvement effect almost disappears. Therefore, the optimal thermal conductivity of the adsorbent should be controlled at about 1.2 W/(m·K).
Natural gas hydrates have vast reserves and are considered a new clean energy source for replacing traditional fossil fuels such as coal and oil in the future.The formation, inhibition and decomposition of natural gas hydrate are affected by many factors.When studying the inhibition and acceleration effect of chemical agents on hydrate decomposition,multiple factors should be considered, such as fresh water or sea water, different gas?liquid ratios in the reactor, and pressure. In this paper, hydrate?related simulation experiments were carried out through a self?designed visualization simulation device for hydrate formation,inhibition and decomposition in wellbore. Under a gas?liquid ratio of (150 ∶ 350),the combined effects of a laboratory?prepared KHI3 inhibitor and different concentrations of NaCl were analyzed to determine the optimal concentration combination. The experiment found that under the compound scheme of 3%NaCl+1%KHI3, hydrate is not easy to generate, but when the concentration of KHI3 is 2%, the nucleation rate of hydrate increases instead,which promotes the generation of hydrate.In practical applications,the concentration of the inhibitor should be strictly controlled to avoid pipeline blockage caused by massive hydrate formation.
Hydrocracking is a crucial technology in the refining and petrochemical sectors. It is of great theoretical and practical significance to deeply understand the mechanism of hydrocracking reactions with the aid of reaction kinetics modeling. This paper recounted the research progress in the kinetic modeling of heavy oil distillation and hydrotreating and shows the methods for computing model parameters corresponding to the modeling method and predicting products. The study showed that the reaction kinetics modeling evolved from the decentralized lumped model based on the distillation range from a macroscopic perspective to a continuous lumped model based on production scenarios and then to a complicated microscopic lumped model at the molecular level. In addition, the study compared the advantages and disadvantages of various models in terms of their capacity to reliably predict the composition of products, the intricacy of parameter estimation, rate coefficients, feed dependence, and experimental data required. It also explained the industrial applicability of the lumped model as well as the construction and method for solving molecular hierarchical reaction networks in molecular lumps. Finally, it gives the development prospects of the lumped kinetic model according to the modeling difficulties, the computing power of computers, and the analysis of technology development trends.
This study uses the solvent extraction method to separate and recover aluminum and nickel from the alkali leaching residue of spent hydrogeneration catalysts. It compared and analyzed the extraction efficiency of P204 (Di (2?ethylhexyl) phosphate) and P507 (2?ethylhexylphosphonic acid mono?2?ethylhexyl ester) and investigated the effects of initial pH, the volume fraction of P204, the saponification rate of P204, and the ratio of V(org)/V(aq) on the extraction of aluminum and nickel in the P204 extraction system. The experimental results show that P204 demonstrates better extraction performance than P507 in the separation of aluminum and nickel. Under a concentration of 35% and saponification ratio of 30% of P204, initial pH of 2.75, and V(org)/V(aq) of 3∶1, the extraction rate of aluminum and nickel is 96.45% and 2.77%, respectively. In the two?stage countercurrent extraction process, the extraction rate of aluminum can reach more than 99.50% while that of nickel is below 3.60%. The loaded organic solvent was stripped at 60 ℃ and V(org)/V(aq) =2∶1 for 20 minutes by 6 mol/L HCl solution, and the stripping efficiency of aluminum in the organic phase is 98.04%. Thus, the separation of aluminum and nickel in spent catalysts can be effectively realized.
The effect of hydraulic retention time (HRT) on the performance of a combined packed sequencing batch biofilm reactor (SBBR) for treating simulated domestic wastewater was investigated.The changes of denitrification performance,denitrification rate and EPS in SBBR were detected and analyzed at different HRT (16 h, 12 h and 8 h).The results indicate that HRT has no significant effect on COD removal rate.Shortening HRT inhibited the activity of microorganisms on the biofilm,increased the mass fraction of TB?EPS and LB?EPS by 30.25% and 29.88%,and decreased the denitrification rate to 64.1%.The best HRT obtained from the experiment was 12 h.
Class II?B reservoirs have become the main exploitation target in Daqing Oilfield, and their geological reserves account for 45.8% of the Class II reservoirs.In view of the huge difference in the exploitation of Class II?B reservoirs,a two?phase mathematical model of viscoelastic polymer solution and crude oil was built,and the logarithmic conformation method was used to transform the model.The VOF method was employed to track the two?phase interface in the displacement process,and thus a two?phase numerical model of viscoelastic polymer solution and crude oil was obtained.Moreover,the effects of pore structure and viscoelasticity of polymer on microscopic oil displacement efficiency were studied by the microscopic model of Class II reservoirs. The results demonstrate that higher reservoir heterogeneity is accompanied by lower microscopic oil displacement efficiency,and the oil displacement efficiency of Class II?A reservoirs with better pore parameters is 2.10% higher than that of Class II?B reservoirs.With the increase in viscosity,the microscopic oil displacement efficiency increases,and the oil displacement efficiency of schemes with a viscosity ratio of (viscosity ratio of polymer to crude oil) 1.5 ∶ 1,2.0 ∶ 1 and 10.0 ∶ 1 is 0.59%,0.80% and 4.10% higher,respectively, than that with a viscosity ratio of 1.0 ∶ 1. With the increase in elasticity, the microscopic oil displacement efficiency rises, but when the elasticity is higher than 13 s,the microscopic oil displacement efficiency decreases slightly,which indicates that the elasticity of polymer solution has an optimal value for improving oil displacement efficiency.The research results provide important theoretical support for the polymer flooding development of Class II?B reservoirs in Daqing oilfield.
In recent years, the global market demand for pressure?sensitive adhesives has shown a steady growth trend. The market demand has reached about 3.5 million tons in 2021, and the estimated size of the global pressure?sensitive adhesive market in 2025 is ＄10 billion. Amid the development of pressure?sensitive adhesive technology and the increase in the application demand for pressure?sensitive adhesives, functionally modified pressure?sensitive adhesives have become a major trend in this field. Acrylate?based pressure?sensitive adhesive is the most widely used pressure?sensitive adhesive at present. Its performance has been improved after modification. Nevertheless, the modification process has some disadvantages, such as environmental pollution and low resource utilization. Since rubber has the advantages of low cost, superb mechanical properties, high and low temperature resistance, and environmental friendliness,and so on.Rubber?modified acrylate?based pressure?sensitive adhesives have become a development trend in this field. This paper summarized the development process of rubber?modified acrylate?based pressure?sensitive adhesives and outlined and compared the types of rubber and the advantages and disadvantages of modified products.
This paper systematically studied the material compatibility, storage stability, and miscibility with diesel fuel of polyoxymethylene dimethyl ethers (PODE n ) from the point of view of its application performance. The results show that the PODE n is generally highly compatible with common metal materials, such as copper, brass, steel, cast iron, cast aluminum, and solder. In comparison, blended diesel fuel with PODE n at a volume fraction of 10% is highly compatible with polyester polyurethane rubber and fluororubber but poorly compatible with nitrile rubber and polyether polyurethane rubber. In the storage stability test conducted at 43 °C for 16 weeks, PODE n demonstrates satisfactory storage stability. Excellent miscibility stability occurs after the blending of automobile diesel fuel with PODE n at a volume fraction of 10%. In general, as a component of blended diesel fuel, PODE n delivers satisfactory application performance.
This paper used a rubber processing analyzer (RPA) to study the effect of different amounts of epoxidized soybean oil and antioxidants on the rheological properties of brominated butyl rubber (BIIR) during the thermal oxidative aging process and discussed the cause of degradation and gel generation of BIIR.The results show that the rheological properties change trend is consistent with the GPC data,which proves that the thermal oxidative aging of BIIR is a process involving both molecular cross?linking and degradation;epoxidized soybean oil and antioxidants can greatly slow down the rate of the gel generation and molecular chain degradation during the aging process of BIIR.Different antioxidants have different anti?aging effects on BIIR.Antioxidant 1076 has a stronger inhibitory effect on oxidative degradation of BIIR than antioxidant 264.
Taking the Bohai Q oilfield as an example, this paper focused on how to improve the effect of liquid production increase in fluvial facies reservoir and counted the effects of measures to increase the production of oil wells in the oilfield in the past five years. The sensitivity of oil wells was analyzed from static and dynamic aspects,and the effects of liquid production increase measures on static and dynamic parameters were studied to analyze the effective timing and scale of increasing liquid production.According to the effect of the measures, classification schemes for the liquid production increase of water?drive reservoir in Bohai fluvial facies were established.The results show that if oil wells in the reservoir are in Class Ⅰ liquid production increase stage (20 000 mD ? m<formation coefficient ≤40 000 mD ? m,0<flow coefficient≤300 mD ? m/(mPa ? s）,25 000 m3<accumulated oil production before liquid production increase≤50 000 m3,0<accumulated liquid production before liquid production increase≤300 000 m3,65%≤water content before liquid production increase<80%),their daily oil production increment after liquid production increase will be possibly greater than 30.0 m3. The daily oil production increment of oil wells in Class Ⅱ liquid production increase stage is between 15.0 m3 and 30.0 m3,and that of oil wells in Class Ⅲ liquid production increase stage is less than 15.0 m3.The high?efficiency stimulation timetable was verified in the southern part of the Bohai Q oilfield.This is of great application value and can provide a basis for the efficient development of offshore fluvial water?drive reservoirs.
