The adsorption of Co2+ and Mn2+ in both simulated and industrial PTA wastewater by CH-90 cation exchange resin was investigated. Different parameters including the pH value, contact time and dosage on the adsorption performance were conducted. The optima adsorption capacity in simulated wastewater was obtained under the condition of pH=3.5 and 2 g/L dosage, and the maximum adsorption capacities were 55.4 mg/g, 50.5 mg/g for Co (II) and Mn (II) respectively. While in industrial wastewater the optima dosage reached high up to 24 g/L likely due to the interference of concentrated COD and the unfavorable pH value. The adsorption kinetics data were analyzed which followed the pseudosecondorder kinetics model. It was shown that the CH-90 resin could be regenerated in strong acid solution and then reused for more than 15 times, which therefore greatly reduced the usecost.
In order to study the effects of the pyrolysis conditions on the coking rate of the HVGO during pyrolytic process, the coking experiment was carried out using the hydrogenation tail oil pyrolysis experiment equipment. Reaction conditions including pyrolysis temperature, wateroil mass ratio and flowing velocity of raw material on the effects of cracking furnace tube coking rate were examined during the pyrolytic process of hydrogenation tail oil. And coking samples were characterized and analyzed by SEM，EDS，DSCTG and EA. The results showed that the coking rate gradually was increased from 2.16 mg/(cm2·h) to 7.90 mg/(cm2·h) with the temperature increment, the coking rate was increased gradually form 3.36 mg/(cm2·h) to 11.02 mg/(cm2·h) with the increasing of the mass flowing rate, and the coking rate was reduced form 7.56 mg/(cm2·h) to 4.89 mg/(cm2·h) with the increasing of the wateroil mass ratio. The carbonhydrogen mass ratio of coke was increased gradually with the increasing of temperature, the prolongation of time and the reducing of wateroil ratio. Carburizing phenomenon happened in coke which formed on the furnace tube wall. To sum up, the most suitable pyrolysis conditions of the HVGO are that the temperature is about 850~850 ℃， the mass flowing rate is about 193.80 g/h and wateroil mass ratio is 0.5~0.7.
Using hydrophobic nanosilicon dioxide, deionized water and basic compounds as the raw material, dry water and dry alkali catalysts such as white granulated sugar were prepared. The effect of mass ratio on form of dry water and alkaline dry alkali was investigated. The effect of the different dry base catalysts, content of active constituents, gas flow and service life of the catalyst on the COS hydrolysis transforming rate were investigated. The results showed that under the condition of room temperature, gas flow of 10 mL/min, dry calcium oxide(CaO(1 g)+deionized water(79 g)+hydrophobic nanosilicon dioxide(20 g) were the optimum catalyst active component ) of 2 g, COS hydrolysis transforming rate reached 90%, and the service life of the catalyst was 340 min.
The slurry bed hydrogenation was studied using vacuum residue from CNOOC Huizhou Refining & Chemical as raw material. The effects of reaction temperature, hydrogen partial pressure, catalyst mass fraction and airspeed on the conversion rate and the yield of each product were investigated in slurry bed hydrocracking reactor of independent research and development. The results showed that under the optimal reaction conditions of reaction temperature 460 ℃, hydrogen partial pressure 14 MPa, hydrogen oil volume ratio 1 000∶1, catalyst mass fraction 300 μg/g and space velocity 1.0 h-1, the residue conversion rate was 90.50%, The coke rate was 5.01%. At the same time, the reaction mechanism and the coking mechanism of the hydrogenation reaction of the suspended sediment were analyzed, which provided theoretical guidance and technical support for the industrialization of the hydrocracking technology.
In this article, effects of hydrogen partial pressure and reaction temperature on removal of 8 kinds of polycyclic aromatic hydrocarbons(PAHs) by hydrogenation was studied by naphthenic vacuum gas oil. The results showed that because of stereohindrance effect of BaP and BeP, PAHs in naphthenic vacuum gas oil were difficult to remove by hydrofining process. The higher the hydrogen partial pressure, the easier it was to remove large space steric hindrance of PAHs. Under the condition of hydrogen partial pressure 4~10 MPa, the effect of hydrogen partial pressure on the extreme value point of the transformation of dynamic control to thermodynamic control was not obvious. However, Under high pressure, the effect of hydrogen partial pressure was obvious, and the hydrogenation process of the PAHs was controlled by dynamic control when the hydrogen partial pressure was 15 MPa.
The plugging effect of micro crosslinked polymer microspheres was studied by using nucleopore membrane filtration experiment. The experimental results show that the salinity has a great effect on the plugging effect of SMGm microspheres. With the increasing of NaCl concentration, the plugging effect becomes better. Under the conditions of same pressure and microsphere concentration, the filtration time of SMGm microspheres is better than that of high pressure. The results show that the effect of concentration on the filtration time is complicated and there is no obvious regularity.
A sulfobetaine amphiphilic polymer, poly(acrylamidecoN,NdimethylNmethacrylamidopropylNpropanesulfonic acid internal saltcoN, Ndodecylacrylamide), was synthesized by using micellar polymerization. The structure of the amphiphilic polymer was characterized by FTIR and 1HNMR. The thickening and viscoelasticity of the amphiphilic polymer in NaCl solution were studied by rotating viscometer and rheometer. The results show that the amphiphilic polymer has the characteristics of salt thickening. The greater salt concentration is, the more obvious its thickening ability is. The increase of salt concentration favors the formation of aggregates of the amphiphilic polymer in solution, and the strength of structure increases, both of which lead to the change of the polymer solution viscoelasticity.
In order to evaluate contribution of emulsification to pressure, the evaluation method of emulsification pressure difference is developed. And then the effect of various factors on emulsification pressure difference is systematically investigated, including the type of flooding systems, the order of interfacial tension and core permeability. The results show that seepage resistance of alkali/surfactant /polymer system is stronger than that of polymer system. The reduction of interfacial tension may improve emulsification pressure difference on certain degree. The core permeability has a great influence on pressure difference and higher emulsification pressure difference is easily obtained for core with lower permeability.
Feldspar Dissolution has an important influence on the development of secondary porosity of tight sandstone reservoir and the storage of oilgas. In order to solve problem of lack of recognition for dissolution mechanism of feldspar of tight sandstone and its influencing factors, through literature researches, a synthetic analysis of dissolution mechanism of feldspar and its influencing factors was made. Results show that organic acid generated from hydrocarbon source rocks and meteoric water both can dissolve feldspar. Feldspar dissolve incongruently, the surface reaction model and the leachedlayer diffusion model have been used to describe the feldspar dissolution mechanism. According to thermodynamic calculation, maximum of Gibbs free energy increment involved in Kfeldspar dissolution reaction, followed by albite, and anorthite dissolution reaction shows the minimum Gibbs free energy increment, disslution reactions of Kfeldspar and albite show negative correlation between Gibbs free energy increment and temperature, but anorthite dissolution reaction shows opposite tendency. Feldspar dissolution is controlled by its composition and structure, temperature and pressure condition, pH and acid type.
Oil displacement efficiency is one of the important parameters affecting the oil reservoir recovery, and the pore volume injection rate is the decisive factor that directly affects the ultimate oil displacement efficiency in the sweep zone. The semi quantitative relationship between the displacement efficiency and the injection volume of pore volume is derived by using the percolation equation expressed by the phase permeability index, combining with the BL theory and the Welge equation. The relation curve satisfies the life cycle theory and the quantitative relation expression between them is deduced according to the law of Logistic growth. At the same time, the optimal pore volume injection ratio is determined by the twoorder derivative curve. With the oil field entering the high water cut stage, the quantitative evaluation method of oil displacement efficiency is of great significance for evaluating the development effect of water flooding reservoir and tap the potential of the reservoir.
Bottomhole pressure is one of the important parameters that affect oil production capacity and the adjustment scheme of oil field. It is also the basis of dynamic analysis of oil and gas wells, and the production capacity of the well is controlled directly. However, due to the complexity of the formation conditions, there is not a systematic method to calculate the bottom hole flow pressure. Based on level conversion method, the fluid in the annular space of an oil sleeve is divided into three different flow patterns of gas column, oil and gas and oil gas water. The field test results show that the average relative error between the measured pressure value and the measured pressure value of the pumping well bottom hole pressure of the pressure gauge is 8.54%, which can meet the actual needs of the field.
Downhole oilwater separation technology can make production liquid divide into water and oil, reduce the surface water treatment and improve oil displacement efficiency. However, pressure difference between output layer and injection layer increases after implementation of this technology. When pressure difference is greater than threshold pressure gradient of interlayer, the interlayer fluid flows. In order to prevent the occurrence of interlayer channeling, numerical model of injectionproduction well is established according to actual formation parameters. After studying the injection and production technology of the same well, the range of cross flow and the upper limit of daily production of single well are obtained, and the limit chart of permeability, thickness and single well production is obtained. When daily production volume of single well is 70 m3 and interlayer permeability is 1×10-3 μm2, the lower limit of interlayer thickness is 2.3 m; When daily production volume of single well is 70 m3 and interlayer thickness is 3 m, the upper limit of interlayer permeability is 1.25×10-3 μm2. When the physical parameters of interlayer are changed, daily production volume of single well can be determined according to the plate, which can be used to guide the development of oilfield development plan.
In order to analyze the movement rules of bypass pig and the characteristics of piggenerated slug dissipation, a dynamic bypass pigging simulation for a real deepwater gas field was conducted. The movement characteristics of pig velocity and the piggenerated slug dissipation were analyzed through changing the pressure drop coefficient and bypass fraction. The study shows that the pig velocity turns out to be powerlaw distribution with the change of pressure drop coefficients, and within the sensitive range, a small change of the pressure drop coefficient will lead to a huge fluctuation of the pig velocity. The average pig velocity has the tendency of linear reduction with the rise of bypass fraction, the change of which helps to control the pig velocity. By taking advantage of bypass gases to carry and sweep the liquid loading in front of the pig，the running resistance can be reduced, thus the stick phenomena of the pig at the bottom of the riser is avoided. The existence of bypass fraction makes the piggenerated slug dissipate along the pigging period. With the increase of the bypass fraction, the hold up of liquid in the slug is reduced, and the liquid film zone is prolonged, thus making the piggenerated slug volume decrease remarkably. For the optimization of the bypass fraction, an overall consideration should be given to the reasonable scope of pig velocity variations and the piggenerated slug volume, making sure it's within the processing capacity of a slug catcher.
Based on the primary production separators (CEPAV2001A/B) of an offshore center platform in domestic, models, in line with actual production, are established. Key parameters in the separators and relief characteristics are investigated when choking accident occurs. Following conclusion is drawing: Firstly, when oil or gas outlet of CEPAV2001A is blocked, separator pressure will surpass the set point of SDV and PSV, and protection devices, such as SDV or PSV, should be taken into account. However, while the water outlet is choked, the pressure will not climb too high to protection; Secondly, according to simulation and comparison, a Gtype PSV with 324.5 mmdiameter is selected for protection under blocking accident; Lastly, equipping with two separators in parallel can ease, or eliminate the pressure climbing of the system.
Natural gas hydrate has the advantages of abundant reserves, large calorific value and low emission, which can mitigate the environmental pollution problems caused by traditional fossil energy. The generation process of natural gas hydrate form is a system with multicomponents and multiphysical states. The nucleation process is complex, which needs to consider the effects of pressure, temperature, promoters, stirring speed and so on. It is difficult to accurately predict the hydrate formation, because the hydrate formation process not only involves thermodynamics problems but also dynamics problems. In our paper, the support vector machine theory combined with experimental data was used to establish support vector machine prediction model for predicting natural gas hydrate equilibrium pressure. The prediction accuracy was estimated by using the mean square error, the square correlation coefficient, the square absolute percentage error and the average absolute error. The results are 8.370 08×10-5，99.897 6%，0.542 4%，1.990 0%，respectively. The pretreatment origin data were normalized (［1，2］) and the nuclear parameter g(4)and punishment factor c(1.414 2) were optimized by using cross validation methods. Simulation results show that the equilibrium pressure obtained by support vector prediction model is good in agreement with the equilibrium obtained by experiments. The better ideal prediction effects prove that the model has advantages of accuracy and reliability. It can provide certain reference for research on natural gas hydrate in future.
Based on different proportions of CO2 and CH4 mixture gas source, the experiment pretreated Changqing oil by using selfmade saturated dissolved gas crude oil processing device under simulated stratum conditions, and then saturated dissolved gas crude oil was got through step by step depressurizing under gathering and transportation conditions (0~3.5 MPa). Crude oil's solubility (Rs), volume factor (Bo), condensation point (TZ), viscosity (μ) and yield value (τy) were studied by using highpressure equipment, which could measure properties of live oil, and highpressure rheometer. The results showed that Rs and Bo increased with the increase of pressure. As the temperature increased, Rs decreased and Bo increased. When experiments were conducted with the same temperature and pressure, Rs (CO2) was the double of Rs(CH4), and the Rs of mixture gas was between the two formers, and the crude oil got better expansion effect with the mixture gas. Among mixture gas, molar ratio of 9∶1 (n(CO2)/n(CH4)) had the best expansion effect, and such mixture gas had best improvement of crude oil's condensation point, viscosity and yield value.
In order to study the problem on cathodic protection interference in deep well casing, in this paper, we use the boundary element method to establish the mathematical model of the pipeline cathodic protection interference. Then the BEASY software is adopt to study the influence of the soil conductivity, coating damage rate, anode output current, the distance between anode location and the casing, and the distance between two well casing on the law of the interference corrosion respectively. Simulation results show that with the increase of soil conductivity, the potential of whole pipeline is reduced, the distribution is uniform, and the degree of interference decreases. Smaller coating defects often make interference more concentrated, while with increase of anode output current, the pipeline interference corrosion intensifies. With the increase of anode distance and the distance between the two casing, the interference degree of casing corrosion reduces, and the interference style changes from anodic interference to cathodic interference. Finally, in view of the interference problems of deep well casing, we connect the two casing electrically, which can effectively avoid the interference corrosion between the casings.
