An iron complex based on polypyridyl ligands was synthesized and characterized. The Electrochemisty of this complex showed that it exhibits two reduction peaks and two oxidation peaks in which the former assigned to FeIII/FeII and FeII/FeI, respectively. The performance of electrocatalytic proton reduction of the complex was examined via using different strength acids (acetic acid, trifluoroacetic acid and tetrafluoroboric acid) as proton sources. From the cyclic voltammograms, we can conclude that the protons catalyzed by different strength acids possess one common feature, that when 1 equivalent of proton source is added, the first reduction peak current intensity increases. The subsequent addition of proton source led to increase slowly of the current intensity with the increase of proton concentration until the effect it tended to stabilize. When tetrafluoroboric acid was used as the proton source, two new reduction peaks appeared, and the peak current of the new reduction peak increased with the increase of the normal concentration of proton source. This shows that when strong acid is used as a proton source, the effect of the electrocatalytic hydrogen production is more obvious.
MgO/13X，Fe2O3/13X and MgO⁃Fe2O3/13X were prepared by impregnation method using 13X molecular sieve as carrier and MgO and Fe2O3 as active components. The structure of the prepared adsorbent was analyzed by XRD，N2 adsorption⁃desorption，TG⁃DTA and other characterization techniques, and the dechlorination effect of the adsorbent on naphtha was investigated. The results show that the metal oxides such as MgO and Fe2O3 are uniformly supported on 13X，the specific surface area and pore size of the modified adsorbent are slightly increased，and the pore volume is decreased. By comparison，the dechlorination effect of MgO⁃Fe2O3/13X adsorbent is best. The optimum conditions were as follows：adsorption time 2 h，adsorption temperature 60 ℃, and ratio of solvent to oil 1∶40，the dechlorination rate was the highest，reaching 89%. The fitting results show that the adsorption process conforms to the quasi⁃secondary kinetic model，mainly the physical adsorption proces.
In recent years, the development of photocatalytic desulfurization catalyst has been a hot topic in the field of clean fuel production. The preparation method, structure, properties and catalytic desulfurization performance of pure phase, doped, supported and heterojunction photocatalytic oxidation desulfurization catalysts were studied. Due to the narrow light response range of pure phase catalysts, doped, loaded and heterogeneous junction catalysts have the expanded light wave region by reducing the bandgap width of catalysts. It is pointed out that the supported catalyst can not only expand the range of light wave range, but also increase the specific surface area of the catalyst and then further improve the activity of it. However, the study of low cost carriers and the regeneration performance of photocatalytic oxidation desulfurization catalysts are important research directions in the future.
Non⁃ionic surfactants, fluorinated cationic surfactants, and fluorocarbon polymers have been evaluated for their ability to alter wettability and injectivity in tight sandstone reservoirs through contact angle tests and injectability tests. The results showed that, compared with other chemical agents, the fluorocarbon polymer CRS⁃850 had better gas wetting inversion effect, and the contact angle of the core surface increases from 45.6° to 92.1°; the self⁃absorption of salt water before wettability changing was 0.360 8 g, the self⁃absorption after treatment dropped to 0.020 6 g, the core self⁃aspiration decreased by 98.85%, and the max self⁃suction rate decreased from 0.053 g/min to 0.002 g/min. The wet reversal agent increased the liquid⁃phase percolation capacity of the coreand the gas⁃driving permeation rate significantly, and the recovery effect of core gas drive permeability is remarkable, which increases by 501.69% to 673.91% on the basis of the gas flooding brine, indicating that the gas⁃wetting reverser has beneficial to remove liquid⁃phase damage in tight sandstone reservoirs.
Drag reduction performance of slick water is one of the key factors affecting fracturing, but the physical mechanism has still not been clearly identified. This paper aims to build a drag reduction modeling of polymer additives dissolved in hydrocarbon in pipe flow on the basis of Giesekus constitutive equation, which was validated by the loop experiment later. The model was applied to calculate the drag reduction rate of polyacrylamide tetrapolymer additive (DR800) in turbulent flow. Indoor loop experiments were introduced for parameter validation and model verification. Although the physical mechanism has still not been clearly identified, the modeling was aimed to explain the contribution of different components: viscous shear stress, Reynolds shear stress and viscoelastic shear stress. It turned out that as the complexity of the flow increased, the viscous contribution and viscoelastic contribution decreased while the turbulence contribution increased. In low Reynolds numbers, viscoelastic shear stress contributed most to friction coefficient while the turbulence can be neglected. In high Reynolds numbers, the contribution of turbulence increased rapidly thus to be the dominating part of the overall contribution, followed by viscoelasticity, and the least was viscous shear stress. By performing consistent comparisons between modeling and experimental results, it can be seen that the model can predict the drag reduction rate of DR800 in a range, which can be used for field production and guidance.
This research adjusted the water flooding characteristic curves in the application of the water, oil and liquid production characterization of air⁃foam flooding reservoir. The numerical simulation method is used to analyze and predict the production performance of air foam flooding reservoir in the stable production stage. Four types of water flooding curves are used in the application of both direct air⁃foam flooding reservoir and the air⁃foam flooding reservoir after water flooding. The results suggest that the type⁃D water flooding characteristic curve is better than other curves in the application of the direct air⁃foam flooding reservoir. The type⁃C and type⁃D water flooding characteristic curves are better performed in the application of the air⁃foam flooding reservoir after water flooding. The characteristic curve of gas production is calculated based on the method proposed by H. R Warner, and can be used to predict the gas⁃oil ratio within three years after the gas breakthrough is stable. Therefore, the gas production volume can be calculated.
In order to improve the development effect of the weak alkaline compound system in the three oil layers of Daqing Oilfield, it is necessary to optimize the formulation of compound system. Based on the combination of CMG numerical simulation and physical experiments, the effects of different concentration of formulation on the interfacial tension, emulsification performance and viscoelasticity of the system were compared and analyzed. The optimum concentration of the formulation was determined. The mechanism of the experimental results and the applicability of the system were also analyzed. The research indicates that the system can achieve ultra⁃low interfacial tension when the concentration of CHSB is between 0.2% and 0.3%, and the water absorption of the system remains below 40% when the concentration of CHSB is 0.3%, which indicates that the system has good emulsifying performance. The measured interfacial shear viscoelasticity is best when the Na2CO3 concentration is 1.2%. The results of the flooding experiment are mutually verified with the numerical simulation results. Based on development effectiveness and economic evaluation, the weak⁃alkaline ASP flooding system with the concentration of polymer HPAM is 1 000 mg/L, surfactant concentration of CHSB is 0.3%, and alkali concentration is 1.0%,which can increase the recovery rate by 23.31%. The results of this study have a guiding role in the application of weak⁃alkaline ASP flooding in the three oil layers.
Acrylic resin is widely used in construction, leather chemicals and other fields because of its low cost, good weather resistance and excellent film formation. However, its surface energy is high and its mechanical properties are poor, which limits its application. In order to improve this deficiency, acrylate was used as the main monomer, dodecafluoroheptyl methacrylate was used as a functional monomer, and trimethylolpropane triacrylate (TMPTA) was used as a crosslinking agent, the hydrophobic fluorinated acrylic resin was synthesized by a shell emulsion polymerization method. The reaction conditions were investigated. The stability and particle size of the emulsion as well as the tensile strength, hardness, hydrophobic angle, chemical structure and thermal stability of the emulsion film were characterized. The results indicate that the addition of TMPTA can effectively improve the tensile strength, hardness and thermal stability of the emulsion film. When TMPTA accounts for 2% of shell monomer mixture, the average particle size of the emulsion is 157.2 nm, and the conversion rate is 97.7%. The comprehensive performance of the emulsion film is best: the water absorption rate is 12.3%, and the decomposition temperature is 394 °C when the weight loss rate is 50%. The angle is 98.9°, the tensile strength is 3.5 MPa, and the hardness is 71.2 HA. Compared with the fluorine⁃containing acrylic resin, the tensile strength is increased by 159.2%, and the thermal stability can be improved by 34.6 °C.
A series of cationic surface active monomers of acrylamide are prepared using a kind of polymerizable acrylamide monomer with brominated alkanes of different carbon chains as materials so as to changing the length of carbon chain of hydrophobic group. The product was identified by IR and 1H⁃NMR. The critical micelle concentration (CMC) and surface tension at CMC value (γCMC) was measured with methods of surface tension and conductibity measures; the solubility of surfactants (AMQC8,AMQC12, AMQC16) was determined by UV spectrophotometry at the same time. The experiment results show that with the growth of hydrophobic carbon chain, critical micelle concentration (CMC) was decreased gradually; the trend of Krafft temperature was gradually rising.
The region of Etuokeqi is an important area for increasing reserves and improving productivity of Changqing oilfield, where the tight sandstone gas reservoir of He 8 and Shan 1 member of Upper Paleozoic is developed. In order to systematically study the controlling factors of high⁃quality reservoirs distribution, this paper applies rock thin slices, cast slices and other conventional analysis data to research controlling factors of high⁃quality reservoirs in the aspects of material sources, sedimentary features, diagenesis, hydrocarbon filling and microcrack development. The results show that, the supply environment of near source parent rock is abundant and quartz content is high, which provides material basis for the development of high⁃quality reservoir; the high porous⁃permeable reservoir formed in the main steam channel belt of delta plain, in which the point bar of braided⁃stream and meandering river is the advantageous sedimentary micro⁃facies; the compaction and cementation of reservoir are widespread, relatively the dissolution effectively improve physical property, so the weak cementation and strong dissolution zones are the major ones of high⁃quality reservoir; the filling of high saturate hydrocarbon promotes dissolution and restrains cementation in the high⁃quality reservoir; micro⁃fractures constitute the drainage system in reservoir and play an important role in reservoir pore expansion and natural gas migration and accumulation.
Hongqi depression in Hailar basin is still in the early stage of exploration. There is no clear understanding of the main types of sedimentary systems, their plane distribution characteristics and the types of dominant reservoir facies belts developed in Nantun formation. Based on seismic, core, mud logging and logging data, the main types of sedimentary systems and their plane distribution characteristics in Nantun formation in Hongqi depression are analyzed in detail under the regional tectonic background. It is considered that fan delta, lake fan and lake are the main types of sedimentary systems, among which fan delta deposits are mainly developed in the west side. In Hongxi steep slope zone and eastern gentle slope zone, the development range is relatively small. In the process of advancing the front sand body, the fault slope break zone collapsed, forming a subsea fan sedimentary system at HS6 wells. The lake sedimentary system mainly developed in the depression area between the western steep slope zone and the eastern gentle slope zone. By analyzing the physical characteristics of core samples of different microfacies types, it is found that the subaqueous distributary channel in fan delta front and braided channel in lake fan are the most favorable oil and gas reservoir facies belts, followed by the distributary channel microfacies in fan delta plain.
The sedimentary characteristics of the sublacustrine fan body and its petroleum geological significance are studied based on core, logging, logging and seismic data. It is found that the sublacustrine fan deposits in this area can be divided into three subfacies: inner fan, middle fan and outer fan, and five types of sedimentation, including main channel, braided channel and turbidite of inner fan. Cumulative microfacies. The lower part of the sublacustrine fan deposit in the Huodomoer structural belt is adjacent to the best source rock section of Nantun Formation. Oil and gas are injected into the sublacustrine fan sand body from the bottom and side, and are usually blocked by faults to form fault⁃lithologic reservoirs or directly blocked by surrounding mudstones to form lenticular lithologic reservoirs. The hydrocarbon accumulation is mainly controlled by reservoirs. Physical characteristics of layers. The experimental analysis shows that the reservoir capacity of different sedimentary microfacies is quite different. The braided channel microfacies of the middle fan is the most favorable reservoir facies type, followed by the main channel microfacies of the inner fan, which is the more favorable reservoir. Oil and gas exploration practice also confirms that high⁃yield wells are mostly located in braided channel microfacies of middle fan and have broad prospects for exploration.
The energy consumption of oil gathering increases rapidly after the oil field enters the high water cut stage.If the normal temperature gathering and transportation is carried out,the cost can be saved,which can bring the enterprise benefit.In order to judge whether the pipeline can carry out normal temperature gathering and transportation,according to the field measured data,the thermo⁃hydraulic calculation model is constructed and modified, the thermo⁃hydraulic coupling calculation is carried out, the normal temperature gathering and transportation radius of the pipeline is determined,and the sensitivity of each influencing factor of the normal temperature gathering and transportation radius is sequenced by the single factor sensitivity analysis method.On this basis,the normal temperature gathering radius chart is developed to provide guidance for the surface normal temperature gathering work.The results show that the modified thermo⁃hydraulic model can predict the pressure drop and temperature drop of the pipeline,and the average relative errors between the calculated value and the measured value are 9.42% and 5.31%.The three most influential factors on the normal temperature gathering radius are the starting point temperature,the starting point pressure and the liquid production.The chart drawn by the above three factors provides the basis for the feasibility of normal temperature gathering and transportation in the pipeline,if not,the temperature and pressure required for the starting point of the pipeline can be determined by querying the chart.
It is one of the important tasks to perform the necessary liquid loading treatment in the daily operation and management of wet gas pipeline. Based on the transient simulation method of pigging process in OLGA software, the development process prediction model of liquid loading in wet gas pipeline was established. The law of liquid loading deposition and development in wet gas pipeline were analyzed. In the end, the design and simulation of a novel liquid loading treatment scheme was carried out. It is pointed out that adding separation devices between wet gas pipelines can significantly reduce the amount of liquid loading and prolong the liquid loading development duration, which plays a positive role in reducing the frequency of pigging and optimizing the volume of terminal treatment devices. Under the same capacity and constant pressure constraints in the end of the pipeline, the separation device between wet gas pipeline can effectively reduce the power demand in the starting point of pipeline, which is conducive to energy saving and consumption reduction of the overall process flow.
The lattice Boltzmann method (LBM) is a mesoscopic numerical simulation method developed in recent decades which has good ability of dealing with complex boundary and parallel computing.The simulations were performed for back facing step flow by LBM, and the characteristics of the back step flow under different Reynolds numbers were obtained. The research results showed that, in the case of low Reynolds number, the distance between the reattachment point and the separation point became larger as the Reynolds number increased, the value of K increased with the increase of Reynolds number, while the growth rate gradually became smaller. In the case of high Reynolds number, the distance between the reattachment point and the separation point increased with the increase of the Reynolds number, and the growth rate gradually decreased. When Re=8000, the distance between the reattachment point and the separation point tended to be stable. The value of K first became larger as the Reynolds number increased, and the increase rate became smaller as the Reynolds number increased, and eventually tended to be stable. For the back step flow under high Reynolds number, the simulation was performed by the LES⁃LBM method, which was in good agreement with the previous experimental data. It showed that the LBM⁃LES model had high accuracy for simulating the back facing step flow after high Reynolds number.
