It is an effective way to enhance the photocatalytic activity by fabricating some defects such as oxygen vacancy into WO ₃ lattice to make nonstoichiometric WO _3-x. This paper firstly describes the mechanism of the effect of oxygen vacancy on the photocatalytic activity of WO ₃, and then, reviews the influence of the localized surface plasmon resonance (LSPR) effect and the synergistic effects of noble metal/carbon containing materials, and oxygen vacancy. Finally, prospectsing and challenging of WO3-x application in the field of photocatalysis are discussed in the end of this work.

The V₂O₅/g⁃C₃N₄ catalyst was prepared by calcination method, using melamine, ammonium metavanadate, boric acid as precursors and methanol as solvent. The structure and morphology of the catalyst were characterized by X⁃Ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT⁃IR), X⁃ray photoelectron spectroscopy (XPS), scanning tunneling microscope(SEM) and brunauer⁃emmett⁃teller(BET). The desulfurization ability of dibenzothiophene (DBT) in model oil was investigated using V₂O₅/g⁃C₃N₄ as catalyst, acetonitrile as extractant and H₂O₂ as oxidant. The effects of reaction temperature, amount of catalyst and extractant, n(H₂O₂)/n(S) molar ratio, and different sulfides on desulfurization rate were investigated. Under the optimum conditions: 5.0 mL model oil, 3.0 mL acetonitrile, n(H₂O₂)/n(DBT)=8, 0.02 g of catalyst, temperature was 30 ℃ and reaction time was 60 min, the desulfurization rate of DBT can reach 91.9%, which can also keep at a higher value at 85.7% after 5 times of catalyst regeneration.

With the implementation of the International Maritime Organization (IMO) sulphur limit policy for marine fuel in 2020, residual marine fuel desulfurization technology has brought widespread attention. The heavy oil is the main component of residual marine fuel, and desulfurization technologies of heavy oil could be categorized as two types: hydrogenation and non⁃hydrogenation technologies. Hydrogenation technologies include fixed bed, ebullating bed, suspended bed, and moving bed, et al. Non⁃hydrogenation technologies include alkali metal compound treatment, selective oxidation⁃extraction/thermolysis/process intensification, electrochemical, biodesulfurization, and sodium, et al. Among these hydro⁃desulfurization technologies, fixed bed hydro⁃treating is more proper in producing residual marine fuel with the sulfur content lower than 0.5% at present. Meanwhile, to produce residual marine fuel with sulfur content lower than 0.1%, it needs to choose the low sulfur containing raw materials and/or blend oils. For non⁃hydrogenation desulfurization technologies, selective oxidation⁃ultrasound and sodium technologies can directly produce heavy fuel oil with sulfur content lower than 0.1%, while sodium desulfurization technology shows a better application prospect.

The Mo ions with high valence state in La_0.5Sr_0.5Fe_0.9Mo_0.1O_{3- δ} (LSFM) were partially substituted by trace amounts of Ni, which was found to weaken the structural stability of La_0.5Sr_0.5Fe_0.9Mo_0.1O_{3- δ} under reducing atmosphere. In this way, Fe⁃Ni alloy nanoparticles precipitated on the surface of the oxidized perovskite under reducing atmosphere, and a composite anode then be prepared showing improved catalytic properties, electrochemical characterizations of which were evaluated. The experimental results indicate that power densities of single cell using La_0.5Sr_0.5Fe_0.9Mo_0.07Ni_0.03O_{3- δ} (LSFMN0.03) as anode are 0.84 W/cm² and 0.62 W/cm² (800 ^oC) with polarization resistance of 0.35 Ω · cm² and 1.01 Ω · cm² (800 ^oC) under H₂ and CO fuels, respectively. The performances of cell with LSFMN0.03 anode are obviously higher than that of La_0.5Sr_0.5Fe_0.9Mo_0.1O_{3- δ} anode. The results of stability tests indicate that, the cell with LSFMN0.03 anode could maintain an excellent electrochemical stability, when the H₂ content in H₂/CO mixture fuel is more than 40%.

A new type of electrode has been prepared by composite of molybdenum disulfide (MoS2) and graphene oxide (GO), and applied in adsorbing Pb(II) in water using capacitance deionization method. The electrode was characterized by X⁃Ray Diffraction (XRD), Raman, Transmission Electron Microscopy(TEM), and Brunauer⁃Emmett⁃Teller(BET). The adsorption mechanism was investigated using X⁃ray photoelectron spectroscopy (XPS), XRD and cyclic voltammetry (CV). The results indicate that GO in the GO/MoS ₂ composite could prevent aggregation of MoS2 and increase the interface of electrode with electrolyte. Besides, the absorption mechanism is proved to be the synergistic absorption effects of double electrode layer and pseudo⁃capacitance, and the former is more effective. The adsorption capacity of GO/MoS ₂ composite electrode is 4 614.9 mg/g, higher than that of pure GO 1 876.9 mg/g and pure MoS2 1 175.4 mg/g, Therefore, GO/MoS ₂ electrode shows superior performance in removal of Pb(II) with high concentration.

The flowback fluid during oil acidizing operation process would directly enter the gathering and transportation system,resulting in deterioration or invalidation of conventional treatment agents,such as demulsifiers.The flowback fluids from the Chengdao Oilfield were divided into two types ，one is high mass concentration,the other is low mass concentration.The high mass concentration flowback fluid is transported back by the operating ships to the shore for further treatment,and the low mass concentration flowback fluid is directly discharged into the gathering and transportation system under the ground.The flowback cycle is long and affected by sea conditions. In order to reasonably estimate the amount of high mass concentration flowback fluid produced by crude oil dehydration process,this paper analyzes the factors affecting the oil⁃water separation of acidified flowback fluid.The volume of flowback fluid and indicators of water in two acidified oil wells were monitored,and thermal deposition of mixed flowback fluid and crude oil were tested. According to the demulsification effect and the water content of crude oil form the joint station, the quantified critical control index are listed as: the pH value of the water from the acidified oil well is higher than 6, the iron ion concentration is lower than 250 mg/L；and the auxiliary control index: the amount of backflow reaches 6 times higher than that of the acid liquid. An inspection method is proposed for the on⁃site operation of the flowback fluid discharging into the gathering and transportation system, properly reducing the flowback time without adding a new processing flow, which is beneficial to increase the oil well production rate and improve economic efficiency.

The optimization of production and operation parameters of oil pipelines can effectively reduce operation energy consumption and improve the economic benefits of pipeline transportation. Aiming at the newly⁃built Qingha oil pipeline in the high and cold regions,the production energy optimization model was established with the constraints of the minimum energy consumption in production and operation,and the constraints of temperature constraints,pressure constraints,and oil pump operating characteristics constraints.In order to improve the solution efficiency,the hybrid PSO⁃Powell algorithm is used to solve the problem.The optimization results show that after optimization,the thermal energy loss is reduced by 38.3%,the pressure energy loss is increased by 90.3%,and the total energy loss is reduced by 26.3%.The energy saving effect is obvious.

Nanbao shallow reservoir is a typical complex fault block reservoir. According to oil products, 60.9% of the reserves belong to conventional thin oil reservoirs. The reservoir has the geological characteristics of active marginal and bottom water, small fault block and small oil area and has come into extra high water cut stage. Because of low water flooding production rate, it is urgent to carry out technical research to further improve reservoir recovery. The paper regarded the reservoir of NmⅡ4② layer in Gao 63⁃10 block as a typical unit. According to the geological characteristics of small oil sands area and sufficient natural energy, the paper puts forward a new oil drive method named deep huff and puff. Based on the oil well，this new oil drive method can improve the swept volume and flushing efficiency and has the advantages of small scale, low investment and flexible adjustment. It provides technical reference for development and adjustment of similar reservoirs at extra⁃high water cut stage.

Grid upscaling is to keep the reservoir physical properties and seepage characteristics of the two models as same as possible before and after upscaling. Thus, the model after upscaling can achieve the same development effect as before upscaling. The permeability is upscaled by harmonic average and arithmetic average. It's found that the relationship curve between recovery degree and water cut after upscaling is different from that before upscaling. Based on reservoir engineering theory, a functional relationship between slope and intercept of Kro/Krw⁃Sw relationship curve and slope and intercept of water⁃oil ratio and recovery relationship curve is derived. Therefore, the phase permeability curve after upscaling can be deduced back. It's found that there is a linear relationship between the displacement distance of the phase permeability curve and the intercept of the fitting line of the water⁃oil ratio curve and the recovery degree curve. The displacement distance of the phase permeability curve can be calculated. The phase translation law is verified by using actual oilfield data. The error of water⁃oil ratio and recovery degree curve between after translation and before coarsening is 3.16%, and the precision is high.

At present,the research on the corrosion rate of the oil casing in the wellbore containing CO2/H2S is the current research hot spot in the field of corrosion and protection. In order to accurately study the corrosion situation of the oil casing and predict the corrosion rate,the weight loss method was first adopted to study the corrosion rate under different corrosion time,and the experimental results were fitted. Secondly, combining the research results of this paper with the previous research content,the Table Curve 3D software for multiple regression was used to determine the corrosion rate prediction model.The results show that the corrosion rate decreases continuously with the increase of time.The fitting of the experimental results R2 is 0.989 3,the error is small.The model established by multiple regression can accurately predict the corrosion rate and the error is within 5%,which meets the accuracy requirements,and can lay the foundation for the on⁃site oil and gas well safety evaluation.

The research and application of supersonic separator (3S for short) have been extensively investigated and applied overseas, but is not yet adequate in China. Numerous theoretical studies have been conducted, which mainly focus on the swirl flow, the internal flow and the condensation process. However, experimental results, specially on condensation and separation mechanism of high⁃pressure natural gas are rarely reported, as well as industrial and field test. A lot of work has been carried out in structural design, mainly focusing on comparative analysis, and no feasible structural design strategies have been proposed. The basic research on droplet condensation is even rarer. At present, the process is mainly characterized by CNT and Gyamathy model. In pratical conditions, an appropriate model needs to be selected for calculation and analysis according to the characteristics of various modified models. In order to improve the efficiencies of gas condensation and gas⁃liquid separation, the next research should focus on the effect of the main factors, such as the inlet temperature & pressure, supersaturation, the converter installation position, the supersonic nozzle structure, on the condensation process, so as to the experimental researches on the high⁃pressure natural gas supersonic separation. The industrialization of domestic supersonic separators will provide an effective tools to the dehydration, deacidification, de⁃heavy hydrocarbon before pipelining for the limited offshore platform.

Based on the dissolved⁃air flotation process, a multiphase flow mixture model numerical simulation was established to simulate the pressure field distribution, particles trace characteristics and the removal effect of oil and suspended matter in the process of settlement separation of produced water by air flotation, the influence of air flotation on the characteristics of the settlement separation flow field of produced water is revealed by comparing with the characteristics of conventional gravity settlement separation. The results indicate that the more stable pressure field distribution is obtained by the sedimentation with dissolved⁃air flotation through adapting the change of treatment amount, and relatively stable and orderly motion tracks of oil droplets and suspended particles with uniform distribution in the flow field are obtained by avoiding vortexing. The removal rates of oil and suspended solids under simulated conditions are increased by 8%~11% compared with the conventional gravity sedimentation separation, and the improvement of the settlement separation effect of produced water was effectively ensured. The construction of the adaptability of air flotation process and the basis of improving the efficiency of produced water treatment are provided by the understanding of the flow field characteristics in the settlement separation of air flotation.

The spread behaviors of the underwater oil droplet on smooth brass substrate were studied using high⁃speed microscopic imaging technology. Chemical and physical modifications were made on the surface of the brass sheet to change its surface properties, and the controllable regulation of superoleophilic–superoleophobic wettability gradient of the surface was achieved successfully. The spreading length and contact angle of the oil droplet rising to different modified surfaces were tested. Different from that in air condition, influence of water surrounding the oil droplet must be considered, which is complicated in water. In this work, on the basis of the energy conservation mechanism, quantitative relationship among the eigenvalues for the spreading behaviors of the oil droplet rising to the surfaces, such as droplet dimensionless spreading length, the droplet impact velocity, droplet size, droplet properties, viscosity of the water and surface wettability, were obtained. An optimized spreading dynamic model was constructed to describe the spreading behaviors of underwater oil droplets on surfaces with different wetting properties, to give support for the design of new oil⁃water separation equipment.

The temperature profile has a decisive influence on the timing of the replacement and blending water of subsea pipeline, as well as smooth restart after shutdown. For a quantitative evaluation on the delay effect resulted from consideration heat storage and dissipation of cover layers, the energy storage capacity of each layer is analyzed theoretically, and the influence of heat storage of steel pipe and soil on the temperature drop of different types of pipelines after shutdown is simulated and calculated. Taking two practical pipelines in Bohai Sea as an example, the transportation scheme is optimized. The results show that the total stored heat by steel is about half of the heat of the crude oil in oil pipeline, 1/4 of the water in water pipeline and 4~16 times of the natural gas in gas pipeline, which depends on the system's pressure. The heat storage and heat dissipation of steel pipe and soil can delay the temperature drop of fluid shutdown. For the insulation pipeline, the stored heat by steel makes a different on temperature drop, while for the non⁃insulation pipeline, the heat by soil has a great impact on temperature profile. Within the crude oil pipeline in Bohai Bay of China, there is about a 3.5~13.5 ℃ temperature increase at the outlet of pipeline when consideration the heat storage and dissipation of cover layers. When the GOR is greater than 10, there is a particularly obvious effect on the temperature drop when shutdown, which is conducive for a safe and smooth transportation. Considering the influence of heat storage and heat dissipation of soil or steel pipe on the temperature drop of shutdown, the water mixing transportation can be delayed or cancelled.

Chiral pyridinone scaffolds widely exist in natural products and biologically active small molecules. Therefore, asymmetric catalytic synthesis with higher efficiency of these chiral compounds is of great importance, which has got significant improvement in this field recently.We reviewed the recent progress of asymmetric synthesis of dihydropyridinones through asymmetric cycloaddition reactions, compared the common points and differences between Aza⁃Diels⁃Alder reactions and [3 + 3] cycloadditions. The detailed catalytic mechanisms and advantages of these reactions were discussed, and the tendency of future development was also prospected.

In order to improve the demulsification efficiency,reduce the processing cost and decrease the damage to the environment during demulsification of oily emulsions,nanoparticles(NPs) have attracted much attention in the field of demulsification,due to their strong controllability and multiple advantages.First,the demulsification mechanisms for magnetic and non⁃magnetic nanoparticles in demulsification were reviewed,providing strategy for the development of new demulsifiers. Secondly,the preparation methods and applications of nanoparticles were summaried.Finally,based on the development of crude oil extraction technology,the current advantages,remaining doubts and difficulties of nanoparticles in the field of demulsification were points out,as well as, the prospects for future research.

This work selected and characterized compositions and properties of three types of fatty acid⁃based and three types of fatty acid ester⁃based antiwear agents. Using hydrogenated diesel oil from Hebei Zhongjie Petrochemical Group Co.Ltd as testing model, the lubrication property and anti⁃emulsification capability of six types of antiwear agents were investigated. The results indicate that lubrication property gradually increases with the increasing content of antiwear agent. Monoglyceride antiwear agent shows the best lubrication property. The attrite speckle diameter of model diesel oil reduces from 734 μm to 345 μm, when the volume of Ester⁃type antiwear agent E is 200 mg/kg. Ester⁃type antiwear agent G has lower film formation capability and lubricating property because of lacking -OH polar group. Acid⁃type antiwear agent exhibits better anti⁃emulsification capability than ester⁃type agent with -OH hydrophilic group. Meanwhile, its anti⁃emulsification capability would get worse when HLB value goes up. Mixing the two materials of acid⁃type and ester⁃type antiwear agents can improve anti⁃emulsification capability of diesel oil, but has less impact on its lubricating property whether the agents are mixed or not.

Based on the three⁃step production process of anion polymerization between styrene and butadiene, a three⁃step model of SBS polymerization process was established using Polymer Plus, to analyze the sensitivity of the raw materials including styrene and butadiene, the catalyst (butyl lithium) and chain transfer agent (tetrahydrofuran,THF) , as well as the impact of the input amount on the molecular weight, polydispersity index (PDI), and yield of the SBS product, guiding further actual production process. The results indicated that purifying the monomers and increasing the input amount for styrene and butadiene can improve the polymerization degree and molecular weight of the product. Besides of that, increasing of the input amount of styrene could decrease the the PDI value. The catalyst had a significant effect on the properties of the product. Thus, the input amount of butyl lithium must be strictly controlled in actual production process. Different from catalyst, chain transfer agent (THF) had a slight influence on the properties of the product and could be used to adjust the molecular weight and degree of polymerization of the product on a small scale without affecting the production yield.

Efficient storage and transportation of hydrogen are the bottlenecks limiting the development of hydrogen economy. One effective way to solve this problem is to store hydrogen in liquid organic hydrogen carriers, such as methanol, which can be released from the organic hydrogen carriers as H2 gas after catalyzed reforming process. The main challenge during this procedure is the development of catalysts capable of executing such a decomposition process. In this work, a novel organometallic compound RuHI(CO)(i⁃Pr⁃Imidazole)(PPh3)2 was synthesized and explored its catalytic applications for hydrogen production during aqueous methanol reforming. The compound was characterized by elemental analysis, infrared spectroscopy, and single⁃crystal X⁃ray diffraction for determining its cystalline structure. The results indicate that the organometallic compound, shows mononuclear structure with six⁃coordinated ruthenium ion in its network, forming the twisted octahedral configuration in the compound. It has been found that reaction conditions such as temperature, the type of alkali, the volume ratio of MeOH and H2O, have profound effects on the reaction efficiencies. Under optimized conditions (110 ℃, 8 mol/L KOH, V(MeOH)/V(H2O)=9∶1),4 μmol the catalyst produces a accumulated TON of 7 9:1 after a 14-day reaction.

The refinery industry is an energy⁃intensive industry. So the efficient recycle and utilization of light hydrocarbon gases will solve the difficulties of energy conservation and environmental protection.The adsorption and the adsorption⁃hydration method were applied to separate C2 from the simulated refinery dry mixture gas of M1(C2H6(11.55%)+C2H4(12.46%)+CH4(29.15%)+N2(27.02%)+H2(19.82%)).The collected mixture gas M2 was secondary separated by ZIF⁃8. The result showed that molar fraction of C2 was decreased to 9.90% after primary separation process using adsorption⁃hydration method.Because of the higher concentration of C2,the values of y_(C_2 ) and MC of product using the adsorption⁃hydration method were better than the adsorption method under the same initial pressure. Because the molar fraction of C2 in M2 was low, the hydrate was difficult to be formed in the system of M2, and the adsorption method with dry ZIF⁃8 was proved to be adaptive to separate the gas mixture of M2 to avoid the negative effects of water in the system of wet ZIF⁃8. Through the two⁃step separation process, the molar fraction of C2 in M1 was decreased from 24.01% to 2.90%.

For most of the anticlinal, fault nose, salt dome and buried hill reservoirs in China, attic oil is easy to form during the waterflooding exploiting process, which reduces the oil recovery efficiency. The top gas injection gravity immiscible displacement process can push oil⁃water interface to the bottom of production wells and improve the final recovery efficiency. An experimental study on the gravity immiscible displacement process of top gas injection is carried out. The horizontal gas injection and top gas injection displacement processes are compared. The results show that the recovery efficiency of the top gas injection is higher than that of horizontal gas injection. Besides, four groups of the gravity immiscible displacement processes of top gas injections are compared. The results show that the final recovery efficiency can increase to a certain extent with the decreasing of gas injection rate, but the duration of the whole displacement process increases sharply. The research indicates that gravity differentiation can increase the final recovery efficiency. At the same time, in consideration of the cost of time, there is a limited gas injection rate, for which the calibration value is 2 mL/h.

The influences of filtration rate and polymer concentration in produced water on the scaling deposition behavior were studied by building the simulation experiment device,considering the characteristics of downward flow filter water collection process and the problems existing in production. Based on the material and internal structure in the water collection tube,a experimental unit model was established,in order to investigate the effect of structure of water collection tube on scaling deposition. In addition,the internal mechanism for the scaling deposition in the water collection tube was discussed.The results indicate that FeS,Fe2O3,CaCO3,and aluminosilicate are the main constituents of scaling depositions in the water collection tube.The high intensitive aggregation and adhesion between the scaling deposition and the inner wall of the water⁃collecting tube are proved to be influenced by temperature, filtration rate and water quality.The water temperature environment of the surface system provides a suitable propagating environment of the sulfate⁃reducing bacteria (SRB), which is used to accelerate the corrosion beneath the scale in the water collection tube. The filtration rate shows two mechanisms of "scaling" and "stripping".The polymer in waste water would induce a synergy effect between "co⁃deposition" and "chelate solubilization". Besides of that,the galvanic corrosion by the structure of the water collection tube is proved to be the internal mechanism for accelerating the scaling deposition.

There is the further potential tapping for the main productive layers in block B, and this is owing to a certain amount of untapped remaining oil after water flooding and polymer flooding. The research focus on the remaining oil distribution and characteristics of post⁃polymer flooding, by means of numerical simulation and the data analysis of sealing coring wells and log interpretation of water flooded layers, which shows the remaining oil horizontally concentrates in fluid diversion line with 2.35 percent higher than main streamline oil saturation and is vertically distributed in layer PⅠ2 and PⅠ3. Therefore, the research of streamline variation to enhance oil recovery has been performed to analyze the influence from different ones on EOR, which indicates that the well pattern infilling in fluid diversion line is optimum. According to the geological characteristics and current well patterns, three kinds of well adjustment patterns have been designed on basis of previous research. The streamline variation by well pattern infilling has been adopted through contrastive analysis which can enhance EOR by predict 1.26 percent by water flooding and 5.17 percent more with high concentration polymer flooding.

M5 block is a typical tight carbonate reservoir with low porosity and permeability. The natural productivity of production wells in this kind of reservoir is low, and it is difficult to reach the limit of economic exploitation. In order to achieve a more ideal stimulation effect, the acid fracturing technology is often used as a stimulation measure for such reservoirs. The fracture conductivity after acid fracturing is an important basis to evaluate the effect of reservoir fracturing, and the fracture conductivity is affected by fracture surface morphology, effective stress and other factors. Therefore, here are the great significance to predict fracture conductivity and characterize the nonuniformity of fracture wall under the effective stress for productivity prediction. The core of this block is taken as the experimental research object, and the stress concentration theory in rock mechanics is introduced to establish the conductivity calculation model by quantitatively analyzing the variation law of opening in the process of wall contact. Finally, the model is verified. There are two main modules in this research: such as the digital characterization module of fracture surface and the conductivity calculation module. The obtained conclusions has a certain reference value for improving the effect of reservoir reconstruction in the later stage of production wells in this block.

The corrosion of A3F and X70 pipeline steel by hydrogen sulfide content in the Liaohe oilfield is studied by employing potentiometric polarization curve and AC impedance technique, and the corrosion morphology of two pipeline steels is observed by the metallurgical microscope. The results show that two kinds of pipeline steels exhibit typical activation control during the electrode process. The corrosion resistance of X70 pipeline steel is significantly better than that of A3F pipeline steel, and the corrosion forms are all local corrosion accompanied by pitting.

Experimental research on liquid evacuation was carried out for pipelines containing vertical riser sections, using air and water as medium, gas⁃liquid flow parameters were measured by high⁃speed cameras and data acquisition instruments, the liquid evacuation process is similar to the severe slug in pipeline⁃riser system. The flow characteristics at the outlet of the riser, the pressure fluctuation at the bottom and the riser pressure drop are compared. The experimental results show that when the gas pressure is low, the gas⁃liquid mixture at the riser outlet is stratified flow and slug flow, and when the gas pressure is large, it is only stratified flow. The greater the gas pressure, the faster the movement speed of the gas front, and the shorter the evacuation time. The gas front shows a tendency to break away from the upper wall surface under higher pressure, its tip is closer to the centerline of the pipe, and the slope of the liquid layer behind the gas nose is greater. The pressure at the riser bottom undergoes three processes, which correspond to the three stages of liquid production, blowout, and liquid oscillation. The greater the gas pressure, the greater the increase in pressure at the riser bottom, and the greater the corresponding peak pressure. The riser pressure drop descends more quickly and greater under higher gas pressure.

Natural gas hydrate, as a new type energy, 90% of them exists in the Marine environment. While Submarine sandstone hydrate, as one of the many hydrate types, has the highest reserves and the best quality. Therefore it has the most development value. This paper introduced and analyzed the influencing factors and reserves prediction of seabed sandstone hydrate formation. In terms of influencing factors, the effects of seabed sandstone particle size, seabed sandstone interface characteristics, salt concentration and gas composition on sandstone hydrate formation were discussed and also analyzed the reasons for its impact. In terms of reserves prediction, the research on exploration field and numerical analysis is summarized, and it pointed out the most suitable solution for predicting the sandstone hydrate reserves. In addition, the research directions in future on hydrate reserve prediction are also proposed. Firstly, there is no uniform conclusion on the effect of seafloor sandstone particle size on hydrate. This may be due to the fact that different scholars do not have a uniform division of particle size range. Therefore unified for the influence of seafloor sandstone porosity on hydrate is studied. Secondly, a function of salt concentration in seawater as a function of the submarine sandstone depth needs to be established, so that hydrate reserves can be predicted more accurately.

With the development of the Bohai oilfield, the proportion of "low production, marginal and viscous" oilfield increases, and the implementation of infill adjustment wells becomes more difficult. Meanwhile, the complex reservoir is easy to lead to landing failure, low drilling rate and downhole accidents. Due to its own limitations, conventional edge detection logging technology can not meet the development and adjustment needs of complex oil and gas reservoirs. It is necessary to introduce the new detection while drilling technology to improve the depth, accuracy and efficiency of edge detection. Along the long⁃distance drilling technology, Schlumberger's high⁃definition multilateral exploration technology and ultra⁃deep multilateral exploration technology are combined in an innovative way. The detection distance is greatly increased to 76.2 meters, with higher resolution, more accurate landing guidance and more precise reservoir description. Through the actual data acquisition, analysis and comprehensive comparison of the adjustment wells C13H1 and P6H1 in the Bohai oilfield, the technology successfully guided the landing, and clearly explored the reservoir boundary more than 20 meters ahead, which greatly improved the reservoir drilling rate，development and production effect.

Subsea well mouth system is an essential equipment for deep⁃sea oil and gas drilling and production. Conventional casing hanger and sealing assembly running tools cannot meet the actual needs. The mechanical model of running tool for casing hanger and sealing assembly was established, which can directly describe the force on the running tool. According to the mechanical model and analysis results, the structure of running tool could be well designed. The contact and strength analysis on casing hanger carrying and driving unit of running tool were conducted using ANSYS finite element analysis software. The analysis results show that the maximum stress values of key components, such as locking block, retaining ring and mandrel of casing hanger, are less than the yield strength of material, which deformation is small enough to be ignored. The structure of the running tool meets the design requirements, and the material used selection also meets the operation standards. This work can provide design experience for the running tool of casing hanger and sealing assembly.

Photocatalysis is one of the important methods to solve the current environmental pollution and energy crisis. However, the photocatalytic efficiency of most photocatalysts is still low. Improving the separation of photogenerated charges is an effective way to enhance the photocatalytic efficiency. Firstly, the paper summarizes the photocatalysis mechanism, and then reviews the effects of built⁃in electric field in semiconductor p⁃n junction, heterophase junctions, polarized surfaces and ferroelectric material polarization on separation efficiency of photogenerated charges and photocatalytic performance, based on the recent domestic and international research progress in improving the separation efficiency of photogenerated charges. Finally, the future development of built⁃in electric field in photocatalysis is prospected.

Titanium dioxide@2,5⁃Dimercapto⁃1,3,4⁃thiadiazole@silicon dioxide (TiO2@DMTD@SiO2) composite materials were synthesized by NaF hydrothermal etching combining with sol⁃gel method. The crystalline structures and morphologies were characterized by X⁃ray diffraction (XRD),Fourier transform infrared (FTIR) spectroscopy,scanning electron microscopy (SEM). The hydrophilicity of the coating was tested by the video optical contact angle, and the anticorrosion performance of the coating was evaluated by electrochemical method.The results show that contact angle of the epoxy coating with TiO2 doped nanocontainers is 71.9°,which can effectively prevent the invasion of corrosive media. Moreover, it has higher corrosion resistance than the blank epoxy coating, after immersing in 3% NaCl solution for 1 to 7 days.

Penetration is not only the technical parameters to characterize the soft and hard degree and anti⁃fatigue at medium temperature of asphalt products,but also the classification index of penetration classification system.The research results in the literature show that the logarithm of penetration is correlated with with Celsius temperature.But correlations between the logarithm and double logarithm of penetration with Celsius temperature,reciprocal of absolute temperature,are rarely studied.In order to investigate the correlations among penetration classification system,viscosity classification system and Performance Grade classification system,ten asphalt products produced by two kinds of crude oil were used to study the linear correlations between the logarithm and double logarithm of penetration with Celsius temperature and reciprocal of absolute temperature at 15, 25 and 30 ℃, respectively,as well as the linear correlation between the slope and intercept of these linear correlations.Through the comparison of correlation coefficients of referenced literatures at home and abroad for the past 80 years,it is found that the linear relationship between the logarithm of penetration and Celsius temperature does not represent the optimal linear relationship between penetration and temperature,and the linear correlation between the logarithm of penetration and reciprocal of absolute temperature is better than that between the logarithm of penetration and Celsius temperature.The correlation coefficient between the slope and intercept in the linear equation between the logarithm of penetration and the reciprocal of absolute temperature is higher.It is found that the relationship between penetration and temperature of all asphalt in the previous studies can be expressed by one equation.

Tetrathienothiophene is an important molecular unit of organic photovoltaic materials.The tetrathienoacene⁃based small molecular semiconductors, combinating a dialkylated tetrathienoacene central core with styrene end⁃capping moieties, are synthesized through Stille coupling reactions.The molecular structure of compound has been analyzed by 1H⁃NMR spectrometry.Thermogravimetric Analysis(TGA),UV⁃visible absorption spectrum(UV⁃Vis),Fluorescence emission spectrum(PL) and Electrochemical cyclic voltammetry(CV) were used to characterized the thermal properties,optical properties and electrochemical properties of the prepared compound.The compound shows UV⁃absorption peaks at 429,453 nm,and a large red shift occurs.The EHOMO=-5.57 eV was calculated by cyclic voltammetry.

In the operation process of anion exchange membrane fuel cell,water molecules are working as the transmission medium of OH-.Therefore,hygroscopic property is one of the most important performances of anion exchange membranes,in addition to conductivity and alkali resistance stability.It is also the focus of research on the improvement of anion exchange membranes.In this paper,two series of anion exchange membranes for fuel cells based on metal organic framework (MOFs) materials were prepared, and their crystal structures and morphologies were characterized by XRD and SEM.In addition,the water content,swelling degree,swelling kinetics, and mechanical properties were tested and analyzed in detail.The results show that the water content,swelling degree, and mechanical properties of the two membranes are much different. Though the swelling kinetic behavior of the two prepared membranes follow Schott's second⁃order swelling kinetic equation,but exhibit different swelling behaviors,due to the different functions of the two component of MOFs.

The construction of C-N bond is an important research field in modern organic synthesis. For C-N bond construction methods, the amination of olefins is the most efficient way which can synthesize multi⁃site products in one⁃step. With the development of photocatalytic redox reactions, some important breakthroughs have been made in the field of amination of alkenes. Using the photocatalytic redox reaction with visible light as a green energy source, the cheap olefin compounds can be catalyzed into biologically active amine compound intermediates. This type of reaction can be widely used in synthetic chemistry, material chemistry, medicine and other fields. Therefore, it is necessary to develop photocatalytic amination of olefins. The research progress over 5 years in five areas, including olefin amidation hydrogenation reaction, olefin amination hydrogenation reaction, olefin halogenation amination reaction, olefin amination alkoxylation reaction, and olefin amination alkylation reaction, is briefly summarized.

At present, for the low permeability fractured reservoir has not formed a perfect identification method of channeling channels, the application of the evaluation index system does not conform to the actual field, the identification method has strong limitations, there are some problems such as big error in the result of recognition at small level. In order to solve these problems, the evaluation system is constructed by deepening the characteristics, mechanism and performance of interporosity flow in low permeability fractured reservoirs, and introducing the corresponding relationship of sand body and permeability of single well and small layer, the model of channeling channel identification is established by using the method of Modulus and objective mathematical analysis and subjective and objective combination weighting. The results show that the evaluation system and the recognition result are more in line with the actual situation of the mine because of the analysis of the pressure⁃sensitive effect, the effect of starting pressure gradient and the introduction of the corresponding relation of sand body for the first time, one channeling channel has not been identified, and the identified result is basically consistent with the field practice, which proves the accuracy of the established method and can provide technical support for the development and adjustment of low permeability fractured reservoirs.

A fully coupled fluid flow and geomechanics model is proposed for ECBM and CO2 underground storage with consideration of multi⁃component multi⁃process transportation in porous media to investigate the complicated geomechanical effects, and the corresponding numerical solver is developed. The effect of geomechanical effects and injection gas components on permeability and injection/production index were also investigated. The results indicate that both effective stress effect and matrix swelling/shrinkage can significantly affect porosity and permeability, but in opposite direction. Matrix swelling induced by CO2 injection can lead to about 90% loss in permeability around injector. The increasing of Young's modulus or decreasing of matrix Langmuir strain, will induce earlier CO2 breakthrough time and lower coalbed methane recovery and CO2 sequestration amount. These results can provide better methane production prediction and support high⁃efficient productivity improvement.

Yanmuxi reservoir in Tuha shows low rock cementation, strong reservoir heterogeneity and high salinity of injected water.Long term water injection development has formed an advantage channel, and the existing technology is difficult to meet the technical requirements of deep liquid flow diversion.The compatibility of inorganic gel and surfactant was studied based on the reservoir geological and fluid characteristics of the target reservoir.The results showed that nonionic surfactant (DWS) solution had good salt resistance property.Inorganic gel (calcium silicate or magnesium silicate) has little effect on DWS solution,indicating that the displacement effect during alternate injection process and profile control will not be affected too much.When surfactant emulsifies with crude oil,"Jiamin effect" can produce additional seepage resistance and liquid flow diversion effect,so the recovery rate increases greatly.In the three combinations of inorganic gels,surfactants and nitrogen,the "inorganic gel+surfactant solution+gas" alternate injection mode exhibits higher injection pressure, and superior liquid flow diverting and expanding the volume effect.

While water exists in the waxy crude oil, gelling process of this non⁃Newtonian oil⁃water two⁃phase system not only has the properties of waxy crude oil but also its own specific characteristic as decrease of temperature. Both the gelling temperature limit and change rule of gelling strength in W/O waxy crude oil emulsion system under different emulsified water fractions, were investigated by rheological measurement. The results indicate that the characteristic gelling temperature and the strength of the gels increase with the increasing of emulsified water fraction, when the temperature decreasing at a certain rate; the gelling temperature in W/O waxy crude oil emulsion system of any given emulsified water fraction rises with the increasing of cooling rate, while the gelling strength decreased with the cooling rate rising under the constant pressure. The research results of the effect of emulsified water on the gelling characteristic for waxy crude oil at cooling process provides necessary support for the development and application of flow technology for multiphase transportation.

In view of the large fluctuation of the gas turbine load in the distributed energy system, the current researches on Organic Rankine Cycle (ORC) pay more attention to the comparison of the thermal performance of the same heat absorption with the initial parameters, but rarely consider the impacts of decrease in both flue gas temperature and mass flow rate on system performance causing by the gas turbine load reduction. Based on the characteristic model constructed by HYSYS platform, optimization scheme of the variable working condition ORC working medium was studied using the narrow⁃point temperature difference in the heat exchanger as the constraint condition. Under the variable load condition of gas⁃fired power plants, the operating parameters of the maximum net output power of the system are optimized. The cycle performances of varies working fluids with different compositions were compared of the characteristics of heat rate, mass flow and AP. The net output of R152a system shows obvious advantages on the heat rate and mass flow rate, compared with that in the mixed working medium in the selected working condition range, while the condenser AP value and the system heat recovery rate exhibit opposite performance. This work provides a reference database for the studying of the binary non⁃azeotropic mixture of ORC system.

The galvanic corrosion behavior of magnesium alloy and Q235 steel system different Sc/Sa(negative / anode area ratio) in simulated solution of tank bottom water in Daxie oil depot was studied by immersion experiment, electrochemical test and micro morphology observation method. The impact of different Sc/Sa on corrosion rate was found out, which curve and expression were fitted. The results show that, the corrosion rate of magnesium alloy anode increases greatly with the increasing of Sc/Sa, but the increasing of corrosion rate for the negative part is not obvious. Based on the galvanic current image, the galvanic current fluctuates and decreases with time. When Sc/Sa is 1.0 or 2.0, the galvanic current decreases obviously, which does not decrease obviously when Sc/Sa is 0.5. The corrosion rate is calculated by galvanic current. It is demonstrated that the galvanic current, as well as the corrosion degree increases linearly with the increase of Sc/Sa.

The development of bottom water reservoir is affected by strong bottom water, low height of oil column, high viscosity of formation crude oil, and complex distribution of separation interlayer, etc. In order to solve the shortcomings of current conventional methods, such as large amount of multi⁃factor data analysis and application limitations, a new method based on BP neural network data mining algorithm for predicting recoverable reserves of horizontal wells in bottom water reservoir is proposed, and its reliability is analyzed by means of mathematical model. Aiming at the static and dynamic data of bottom⁃water reservoir, the effective hidden information is fully mined, and a data⁃driven model for the prediction of recoverable reserves of bottom⁃water reservoir is constructed on the basis of the establishment of basic data set. The results of practical application show that this method can realize the quantitative analysis of the influencing factors and the limit of technical parameters of horizontal well development in bottom⁃water reservoir, the maximum error of recoverable reserves prediction is less than 8%, and the fitting effect is good, which can be further applied to the research of production performance, development limit and well location design of horizontal Wells in bottom⁃water reservoir.

In order to solve the problem that large quantities of heavy crude oil imported from Venezuela cannot be transported by pipeline at normal temperature after arriving at shore，the transportation technology research was carried out aiming at some key problems such as the quick prediction of diluted heavy crude oil viscosity,the stability and uniformity evaluation of diluted heavy crude oil and the determination of safe blending proportions under different transportation conditions，and a set of analysis method for transporting diluted heavy crude oil at normal temperature based on indoor blending experiments and assisted by simulation calculation was established.Based on the statistical analysis of basic physical properties of 16 kinds of imported light crude oils ,the indoor experiments of blending Venezuela heavy crude oil with three kinds of typical light crude oil oils respectively were carried out,and quick reference tables of viscosity of diluted heavy crude oils with different blend proportions were established by these indoor experiment data. As long as the viscosity of light crude oil at 20 ℃ was known, the viscosity of diluted heavy crude oil at different blending proportions and temperatures can be quickly determined by using these quick reference tables.The stability and uniformity of diluted heavy crude oil were tested by let stand tests.These tests show that the diluted heavy crude oil samples still keep good stability and uniformity after 10 days of standing.Taking Ridong pipeline as an example,the process of transporting diluted Venezuela heavy crude oil was simulated by self⁃developed calculation program, and a kind of method to determine the safe blending proportions and feasible operation plans was proposed.These research results can also support the safety operation of pipeline of transporting diluted heavy crude oil at normal temperature.

The hierarchical zeolite has become a hotspot in the current molecular sieve research field due to its advantages of efficient mass transfer and shape selection catalysis.The unclear mass transfer optimization mechanism has become a bottleneck restricting the design and development of hierarchical zeolite.This paper briefly introduces recent research and development status of the hierarchical zeolite,reviewes with emphasis the research progress in mass transfer mechanism of Hierarchical zeolite,the current research challenges and the analysis of current research strategy etc,and discussed the significance of mass transfer mechanism in the research and development of graded porous molecular sieve materials and the prospect of future development.

According to anti?Bredt rule,if olefin strain (OS) of alkene with double bond in bridgehead is less than 71 kJ/mol,it can be isolated at room temperature.The OS of bicyclo[4.2.1]?1(8)?nonylene is less than 71 kJ/mol,conforming with anti?Bredt rule.A novel synthetic route of gram?scalable bicyclo[4.2.1]?1(8)?nonylene was reported,which was synthesized in seven steps with 17% overall yield,characterized by starting from 2?cycloheptenone using a vinyl magnesium bromide?mediated 1,4?conjugation as addition and an intramolecular Wittig reaction as the key steps.Different from the previous synthesis,the raw materials used in this method are all commercially available,which avoids the synthesis of raw materials themselves and simplifies the synthesis route.In addition,intramolecular Wittig reaction is used as the key reaction to avoid the generation of isomers.It is very challenging to synthesize alkene with double bond in bridgehead because of their high strain energy and instability.However, development of synthetic routes for such compounds is of great significance for further study of their chemical properties and application.

Titanium metal?organic frameworks (MIL?125(Ti)) were used as the core and shell materials.On this basis,a core?shell material with larger and more uniform particle size denoted as MIL?125(Ti) coated MIL?125(Ti) (MOFs@MOFs) was synthesized by the epitaxial growth method, which was then calcined to obtain micron?sized chromatographic packing TiO₂.The preparation conditions,incuding adding amount of core materials,dilution times of shell solution,reaction time,and coating layers,were investigated,which were optimized to be that the amount of core was 30 mg,the shell solution should not be diluted,the reaction time was 24 h,and the coating layer was 1 layer.The results showed that the anatase TiO₂ materials with a specific surface area of 76.0 m²/g,a particle size of about 7 μm,and a thickness of about 2.5 μm,were successfully prepared by MOFs@MOFs,The synthesized TiO₂ not only retained the excellent performance of MOFs@MOFs but also featured a large particle size and adjustable porous structure.In addition,the method was easy to operate without demanding synthesis conditions,and had strong operability.