Due to the existence of gas⁃liquid⁃solid three⁃phase and the installation of internal components, the transfer and reaction process of slurry bed reactor in Fischer⁃Tropsch synthesis is complex, which poses great challenges in reactor design and industrial scale⁃up. This paper introduced the structure of slurry bubble column reactor and also reviewed the recent researches on dynamics and reactor scale⁃ups. The influences of internals on hydrodynamics and scale⁃up were analyzed as well. Crucial factors in terms of structure and model in the process of reactor design were included, which may provide a feasible scheme and solution for optimization and scale⁃up of slurry bubble column reactor.
Nanosized lithium orthosilicate sorbent has been prepared by precipitation, and its CO2 capture performance has been evaluated. The particle size of the adsorbent is small and uniform, which leads to a significant reduction of the calcination temperature and desorption temperature, thus greatly reducing the process energy consumption. Under optimum calcination temperature, relative higher kinetic absorption capacity, i.e., 17.8% within 5 minutes under volume fraction 12.5% CO2 model flue gas stream by absorption⁃desorption cyclic test, has been obtained. Static CO2 absorption test at different temperatures were well fitted by the double exponential model, demonstrating the double shell mechanism. The rate⁃determining step, Li diffusion rate from the bulk to the surface, was greatly improved even in low⁃CO2⁃concentration model flue gas owing to its nano⁃scale character. Therefore, this study has provided a simple and efficient preparation method for nanosized ceramic sorbents, which is promising for thermo⁃swing fluidized bed process.
Hβ zeolites were modified by hydrochloric acid. The crystal structure, textual properties and total acid content of the Hβ zeolites were characterized by XRD, N2 adsorption and NH3TPD. Using thiophene as the probe molecule, the mass transfer behavior of Hβ zeolites modified by hydrochloric acid was studied by Frequency Response. The results showed that hydrochloric acid washed away the non skeleton aluminum which blocked the pore of zeolites, enhanced the permeability of molecular sieve pore and improved the mass transfer performance of the molecular sieve. In the frequency response spectrum, the response intensity of thiophene in the modified Hβ zeolites was obviously greater than that in the unmodified zeolite. The mass transfer performance of modified Hβ zeolites was improved, and the ability to adsorb thiophene was also enhanced obviously, which was significant for catalyzing thiophene reaction and optimizing industrial desulfurization.
The cracking performance of ethylene plant was evaluated based on the design indexes and production data of cracking raw materials (naphtha and hydrogenated tail oil) in Fushun petrochemical ethylene plant. Firstly, the component, physical parameter and cracked gas composition of ethylene cracking feedstock were measured, and then the decomposition temperature, dilution ratio, pace time, cleaning cycle, oil price and fragmentation depth were compared. At the same time, the influence the properties of pyrolysis raw materials on the product yield was examined. The last step was to make a comparison between manufacturing data and design indicator, and to propose some concrete measures to optimize its system. The results demonstrated that the physical property indexes of naphtha and hydrogenation tail oil were within the range of allowable design, but their cracked gas yield exceeded the design value. The total yield of ethylene, diene, methane and hydrogen derived from cracking naphtha was 4.57% higher than the result of crackers originated in hydrogenation tail oil. The yield of ethylene and diene showed 0.44% and 0.63% rise respectively. However, C4, C5, C6-C8, C9 and fuel oil from cracking naphtha had relative lower yield (5.18%) in contrast to those from cracking hydrogenation tail oil.
The carrier of hierarchical porous TiO2⁃Al2O3 and the catalyst Ni2P/TiO2⁃Al2O3 were prepared. The catalytic performance of the Ni2P/TiO2⁃Al2O3 was compared with the Ni2P loaded on the mesoporous Al2O3 and γ⁃Al2O3. The influence of the technological conditions, including reaction temperature, hydrogen oil ratio, mass space velocity and reaction pressure, were investigated by Orthogonal test and single factor exploration, respectively. The optimized technological conditions were obtained. The results showed that the hydrogenation catalyst Ni2P/TiO2⁃Al2O3 possessed more excellent de⁃aromatic rate and the selectivity of decahydronaphthalene compared with the ordinary catalyst of Ni2P/γ⁃Al2O3 and Ni2P/Al2O3. For the de⁃aromatic rate and the selectivity of decahydronaphthalene, the reaction pressure and temperature had more significantly affection to the hydrogen / oil ratio and the mass space velocity. According to the results of orthogonal test, the optimum reaction conditions of the hierarchical porous Ni2P/TiO2⁃Al2O3 catalyst in the hydrodeaphthalene reaction were investigated. The reaction temperature was 300 ℃, the reaction pressure was 4 MPa, the hydrogen / oil ratio was 500, and the mass space velocity was 1 h-1. The removal rate of naphthalene and the selectivity of decahydronaphthalene reached the highest, which were 99.2% and 72.0%, respectively.
In order to realize the efficient development of the oilfield,it is needed to evaluate the productivity of the reservoir. According to the structure of horizontal well, the form of fracture and the distance of fracture, combined with the theory of seepage mechanics, a well test analysis model for multistage fractured horizontal wells considering wellbore storage and skin factor is established. A typical curve fitting chart of pressure and derivative is obtained, and a well testing interpretation software system based on the theoretical plate is developed. Based on the well test interpretation software system compiled by the theoretical plate, the IPR curve and the production decline curve are plotted by using multistage fracturing horizontal well test interpretation software.The results show that under the same production conditions, the influence of fracture distance and crack skin factor on productivity is less than the effect of crack half length on productivity. According to the curve of production flow rate with bottomhole flow at different production stages and the curve of output with production time at different bottomhole flow pressures, and the production capacity is predicted and evaluated at different stages of fracturing horizontal wells. It provides a strong guarantee for the efficient development of multistage fracturing horizontal wells.
Using the method of “pessure⁃consumption” and Micro⁃flow measurement instrument the start⁃up pressure gradient of water flooding and microemulsion flooding in low permeability reservoir is actually measured.Analyzed the characteristics of nonlinear seepage and the effect with mechanization of start⁃up pressure gradient of microemulsion in low permeability reservoir.The result show that the pessure⁃consumption curve of low permeability reservoir is a concave⁃up curve which has non⁃Darcy seepage flow characteristic. The start⁃up pressure gradient and permeability in a power,and start⁃up pressure gradient are increasing with the reduction of permeability.The average start⁃up pressure gradient of flooding water is 0.050 MPa/m,and the average start⁃up pressure gradient of micro emulsion flooding is 0.039 MPa/m.The reason why microemulsion can reduce start⁃up pressure gradient is that it can decrease interfacial tension and resistance coefficient.The lower the interfacial tension of micro emulsion,the small start⁃up pressure gradient.
In order to meet the practical needs of profile control and flooding technology in Bohai reservoir, the hydration dynamic characteristics and seepage characteristics of polymer microspheres were studied in this paper. Results indicate that, with the prolonging of hydration time, the expansion ratio of polymer microspheres increases, and the final expansion ratio is about 4.5. When the hydration time is less than 50 h, the expansion velocity is faster, then the expansion velocity slows down, and finally reaches stable after 360 h. Compared with the size distribution of molecular aggregates in the polymer solution, the size distribution of the two polymer microspheres is relatively concentrated. The initial median particle size of 10# microspheres is 4.36μm, and then reaches 20.00 μm after hydration for 240 h. The initial median particle size of 11# microspheres is 8.45 μm, and then reaches 40.0 μm after hydration for 360 h. The expansion ratio is about 4.72. In the injection process of polymer microsphere, the adhesion between particles and the pore filtering effect can cause the retention and temporary plugging of polymer microsphere in the core end, which leads to the abnormal increase of the pressure in the injection process. The polymer microspheres can further hydration expand in the core pore, showing the seepage characteristics of “migration, trapping, re migration and re trapping......”.
At present, the understanding of turbidite fan sedimentary system on reservoir physical property of upper Es3 member in Western Chezhen sub⁃sag is scarce, especially the indirect influence of different sedimentary microfacies on reservoir physical properties by controlling diagenesis lacks systematic and regular knowledge. Based on the study of the overall sedimentary characteristics and the data of reservoir physical properties, casting thin section identification, X⁃ray diffraction analysis and core routine analysis, this paper studies the influence of three main sedimentary microfacies types on reservoir physical properties of turbidite fan system in Chexi depression. The results show that study area developes 4 kinds of diagenesis including compact and pressure solution, cementation, dissolution, metasomatism. There are 3 kinds of sedimentary micro⁃facies including braided channel, interchannel, and slump turbidite fan. Besides, there is not only direct effect micro⁃facies on diagenesis, but also indirect effect though dominate the distribution of diagenesis. By comprehensive consideration, three favorable oil⁃bearing blocks have been selected.
Combining with the physical property data in the study area, logging interpretation results and field test data, the distribution function curve method and the method of oil are used to calculate the physical property lower limit and depth of the effective reservoir in the lower member of Sha 3 of Chengnan fault zone. The physical relationship between them is fitted by software. On this basis, the controlling effects of burial depth, lithology, sedimentary facies and diagenesis on the development of effective reservoirs in the study area are discussed. The results show that the effective reservoir property in the study area by the factors such as buried depth, sedimentation and diagenesis control together, effective reservoir physical property lower limit decreases with increasing of buried depth, advantage for fine breccia facies and conglomeratic sandstone, due to the deep compaction cut hole depth obviously later dissolution as the main mechanism of hole, which is the main control factors of sedimentary facies. The effective reservoir in the study area are mainly distributed in the nearshore submarine fan, sublacustrine fan and fan delta, fan delta deposition is the most favorable sedimentary facies.
In order to reduce the drilling cycle, it is necessary to improve the applicability of the mechanical specific energy model. In this paper, the mechanics analysis is based on the mechanical energy model proposed by R. Teale, the drilling pressure and torques of the vertical and inclined wells are modified respectively, and the intersection model is obtained. The results show that the vertical power is constant greater than that of tangential power at the same depth. When tthe vertical work is tangled with tangential work, the phenomenon of "venting" reflects the good geological properties of the layer. The merit model can better reflect the bottom, and the mechanical ratio can be more suitable for the evaluation of the physical properties of logging, avoiding the influence of non⁃objective factors on the baseline of the mechanical specific energy ratio model, and enhancing the accuracy of field physical property evaluation.
Internal batch mixier with 4WS(four⁃wing) rotor is the novel mixing equipment, which has some advantages to achieve better mixing efficiency in short time, such as small helical angle, wide sweep range and quick feed. Finite element method was adopted to calculate the three⁃dimensional transient velocity distribution of the 4WS rotor internal mixer. The effects of gap between rotor and barrel on the mixing efficiency were analyzed by means of shear rate, Lyapunov Exponent, instantaneous mixing efficiency, time averaged mixing efficiency, segregation scale and logarithm of stretching. The results show that the smallest rotor clearance has the better mixing performance within limits.
In this paper, the adsorption behavior of polyoctadecyl acrylate (POA) in model crude oil on the surface of nano⁃SiO2 particles modified by methyl was investigated by performing molecular dynamics (MD) simulations. The adsorption model of model crude oil including POA molecule on the surface of nano⁃SiO2 particles was constructed. The model crude oil consists of asphaltene, resin, aromatic hydrocarbons and alkanes. The surface of nano⁃SiO2 particles was modified with three different degree of methyl. Several parameters such as the adsorption energy, relative density distribution, the mean square displacement and radial distribution function were analyzed. The results show that the unmodified surface is firstly adsorbed by asphaltene of strong polarity while the surface of 100% methyl⁃modified is firstly adsorbed by n⁃alkanes. The surface of 50% methyl⁃modified particles is firstly adsorbed by aromatic hydrocarbons. The results also indicate that the surface of 50% methyl⁃modified particles is not only more conducive to the stable adsorption of POA molecules, but also conducive to POA molecules to form a better adsorption configuration. What’ more, on the surface of 50% methyl⁃modified particles, the interaction between POA molecule and C24H50 molecules is stronger, and the distribution of C24H50 molecules is more aggregated. Finally, the study of this paper provides a method for studying the mechanism of pour point depressants composed of polymer and inorganic nanoparticle and provides theoretical guidance for the experimental modification of nanometer particles in nano⁃hybrid pour point depressant.
The determination of effective thermal conductivity of wax deposits is an important part of calculation of the heat transfer in wax deposition. Based on the analysis of effective thermal conductivity calculation method of heterogeneous binary mixture, a model suitable for calculating effective thermal conductivity of wax deposits is determined, and the influence of different effective thermal conductivity calculation methods on heat transfer characteristics of pipelines is compared and analyzed. The results show that the effective thermal conductivity of wax deposits becomes larger with the increase of mass fraction of wax in the sediments. Under the same mass fraction of wax, effective thermal conductivity calculated by parallel model is the largest, followed by ME2 model, EMT model and series model, and the calculation results of ME2 model and EMT model are close. The hypothesis of EMT model is similar to the structure distribution of actual wax deposits, so it is recommended to use the EMT model to calculate effective thermal conductivity of wax deposits. The temperature along the pipe section calculated by EMT model and M correlation is very close, and radial temperature gradient obtained by EMT model is higher than M correlation. Generally speaking, the heat transfer calculation results of pipelines obtained by EMT model and M correlation have little difference, but correlation is more convenient and has certain advantages.
