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.
