Taking Suizhong 36-1 70# asphalt as matrix asphalt, minus three line furfural extract oil as compatilizer, the effects of four modifiers on the conventional, high temperature shear rheological and thermal storage properties of suizhong asphalt were investigated. The morphological characteristics of SBS phase in asphalt under different modifiers were analyzed. The results show that the modified asphalt prepared by the modifier A has excellent performance in the high and low temperature and it has good compatibility with Suizhong asphalt. With LG501S, YH791, A and B as the modifier, the rut factor G*/sinδdelta of modified asphalt increases gradually, and the high temperature performance is enhanced. By screening the modifiers and stabilizers, the modifier A and stabilizer 2# are selected as raw materials for the production of I-D modified bitumen from Suizhong 36-1 asphalt.
The formation and stability mechanism of crude oil foam is the key to solve the problem of crude oil foaming. The basic properties of foam, features of crude oil foam are introduced in this paper and the research status of crude oil foam formation and stability mechanism is expounded. The experimental research methods of crude oil foam are summarized, and the influencing factors of crude oil foam formation and stability such as the composition of oil, temperature and gas properties are discussed according to experimental methods. Based on the current research, the future direction of research is proposed. The stability mechanism of crude oil foam and the influence of mechanical action on foam are still to be studied and there is no practical test method of crude oil foam at present.
The catalytic cracking performances of several propane deasphalted oil obtained in our earlier work were investigated in a fixed fluidized bed reactor at the reaction temperature of 490 ℃, catalyst to oil mass ratio of 5 (catalysts 80 g) and space velocity of 15 h-1. It was found that the propane deasphalting oil with the highest saturated fraction mass fraction of vacuum residuum was a good FCC feedstock. the product distribution and selectivity of the deasphalted oil from vacuum residuum blending FCC slurry oil were better than that from FCC slurry oil. But for the deasphalted oil from FCC, slurry oil had lower conversion and light oil yield, and the cracking performance was also poor.
After internal and external diffusion was eliminated, the kinetics of hydration of Myrac Aldehyde was studied in a batch stirred reactor with isopropyl alcohol as solvent and cation exchange resin as catalyst. The effects of agitation speed, catalyst particle size，temperature of reaction and catalyst concentration on the reaction rate of hydration reaction were studied. The kinetics data of hydration reaction were fitted by LHHW kinetics model. Preexponential factors and reaction activation energy were fitted by Arrhenius equation. The forward and reverse preexponential factors were 0.090 46 mol/(g•s) and 5.317 40 mol/(g•s), respectively. The forward and reverse reaction activation energy were 1.724 7×104 J/mol and 3.391 2×104 J/mol, respectively.
Three different methods (ultrasonic dispersion, hydrothermal method and calcination) were used to prepared g-C3N4/WO3 heterojunctions. Obtained catalysts were characterized with X-ray diffraction (XRD), UVvis spectroscopy, nitrogen adsorption, X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and Electrochemical impedance spectroscopy (EIS). The results showed that the interaction between g-C3N4/WO3 and WO3 was obviously affected by the preparation methods, resulting in the significant difference in separation rate of photogenerated electrons and holes. The photocatalytic performances were detected in photocatalytic Rhodamine B (RhB) degradation under simulated visible light. The results indicated that activities of g-C3N4/WO3 heterojunction composites were evidently higher than that of single g-C3N4/WO3 or WO3 semiconductor, and the heterojunction semiconductor prepared by the hydrothermal method showed the highest photocatalytic activity.
Using FeCl3·6H2O and NaOH as reactants, polyethylene glycol 200 as template agent, rodlikeFe2O3 nano-crystalline was synthesized. The samples were characterized by TEM, XRD and FI-IR.The results of TEM show that morphology of samples were changed with conditions of preparation.The synthetic conditions of nano-rods were optimized. The Fe2O3 nanorods were modified by sodium lauryl sulfate and its effect of oxidative desulfurization of thiophene was studied. Experiments show that modified Fe2O3 nanorods could significantly promote the removal of thiophene in the simulated oil due to effect of coupling existed between modified Fe2O3 catalyst and ultrasonic. The desulphurization rate could reach 100%.
This paper researches the seepage characteristics and oil displacement effect of polymer solution and weak-base ternary compound system, taking the reservoir geology and fluid from Daqing Oilfield as research object, taking injectionpressure and oil recovery as the evaluation indexes. Results show that, under the condition of the same oil displacement agent viscosity and slug size, the oil recovery increment of weak-base ASP flooding is larger than that of polymer flooding. Because there are emulsification and Jamin effect during weak-base ASP flooding, which can increase seepage resistance and injection-pressure, and its oil sweep efficiency is also higher. Compared with ternary compound system with scaleremoval water, there are carbonate micro particles in the sewage ternary compound system, which can be detained in porous media. This can increase seepage resistance and cause fluid diversion effect, which eventually leads to a large increase in oil recovery. Compared with constant-speed experiment, it is early for constantpressure experiment to adopt peak-pressure, which accelerates the forward speed of agent in the core high permeability layer and shortens the breakthrough time. As a result, the sweep efficiency and oil displacement efficiency of constantpressure experiment is lower.
In order to achieve the effect of decompression and augmented injection, sulphonate surfactant was adopted to reduce IFT between oil and water by Taibei SII group, which required optimizing and adjusting formulation of surfactant. The variety and concentration of alcohols and salt assistants were screened to reduce IFT of oil-water interface, and test of evaluation on surfactant resistance was used to highlight its characteristics and the optimal application conditions. The results show that the effect of mixed reagent of 0.1%~0.8% ethanol, normal butyl alcohol and sulphonate outperforms that of methanol, normal propyl alcohol and glycerin. With increase of salt concentration, the surface tension first descends and then rises, showing a L-shaped curve. The surfactant has better activity on formation of 50 ℃ within 15 d. The influence of mineralization degree on IFT between oil and surfactant approximates to "Ω" shape. The slightly alkaline condition is favorable for the action of surfactant. Core displacement test shows that optimized surfactant can achieve 18.7% depressurization, and the effect is better.
In view of high permeability and serious water channeling in Bohai oilfield, a new type selfassembled particles profile control system was investigated. Laboratory plugging and oil displacement experiments were carried out with different injection modes. Static experiments showed that self-assembled particles had good properties of heat-resistance and salt-resistance, and it was applicable on the reservoir conditions of 65 ℃ and 35 000 mg/L. Plugging experiments showed that for sand-filled pipe which permeability was about 10 000×10-3 μm2 , after particles plugging with guanidine gum or polymer as suspension liquid, the permeability was dropped to about 3 000×10-3 μm2 and effective plugging rate was above 70%. Oil displacement experiments showed that for parallel sand-filled pipes which permeability was about 20 000×10-3 ，4 000×10-3 μm2 , when water-flooding recovery was 27.34%～28.17%, the degree of extraction can be improved by 28.57%～38.76% after injecting 0.4 PV self-assembled particles displacement system, and it can be up to 55.91%～66.80% finally. It should be noted the injection mode with guanidine gum or polymer was better. Mechanism analysis revealed selfassembled particles displacement system had plugging functions such as filling, bridging and adhesion.
The acidizing cleanup emulsion phenomenon is serious, and it can not enter the power off process. In view of the above problems, indoor simulation experiments were carried out to explore the influence of temperature, pH value, moisture content, the oil phase of the returned liquid, the water phase of the returned liquid, the iron-containing compound and the mud content on electric dehydration of returned acidizing fluids. It was found that when the impurities in the oil were less, the water phase and water content of the returned acidizing fluids had little effect on the electric dehydration, the increasing of the temperature was beneficial to the effluent demulsification, and neutral pH value was the most suitable condition for the demulsification of the returned fluids. The ferric hydroxide colloid which was wrapped with crude oil, sludge and free water in oil, forming a very high conductivity intermediate layer between the oil phase and the water phase, was the main cause of electric dehydrator trip.
Based on the previous research, this paper establishes the relationship between the dewatering transformation of the clay minerals and the diagenetic stages and the formation of pore fractures. The influence of temperature, time, pressure, pore fluid properties and thermal evolution of organic matter on the transformation of clay minerals is summarized. By comparing the paleogeotemperature in the transformation of various clay minerals and change of fluid properties, the diagenesis evolution of shale is divided into three stages, and the difference of main diagenetic reaction in each stage leads to the variance of mineral assemblage.The adsorption capacity of methane is closely related to the transformation of clay minerals in shale diagenesis.The experimental results show that the order is smectite>illite/smectite mixedlayer>kaolinite>chlorite>illite. Illitization of smectite and chloritization of smectite are important diagenetic reactions, and the study and establishment of their genetic mechanism model have a certain reference significance for the study of shale reservoir.
Granular layer filtration is widely used in the treatment system of oilfield produced water, and water distribution of granular layer filter which directly affects the purification effects of produced water plays the same significant role as the selection and arrangement of granular layer. The model of filter was built and unstructured grids were generated by Gambit. The flow rate field in the model was calculated by Fluent combined with DPM model. Based on the DPM model in Fluent software, a numerical simulation of pressure field distribution, filtration pressure drop along the axis, pathlines of particles, and particles distribution and aggregation behaviors were simulated and calculated. Then, water distribution characteristic in pressure filter of produced water was described, and optimization of water distribution process was realized. The results showed that the good performance of water distribution was obtained and the pressure drop in the filter with sieve tubes was reduced by 30.56% compared with the filter with slots. Furthermore, the filter with nine sieve tubes was optimized by its excellent water distribution characteristic. Such a numerical simulation method can provide effective support for optimization of filtration process and purification of produced water.
Hydrate formation process is a mass transfer process between gas and liquid, which lead to phase change. As the mass transfer efficiency between gas and liquid is low, the hydrate formation rate is slow, as the mass transfer efficacy is low, the amount of consumed gas is small. Therefore, improving the hydrate formation rate and storage capacity is actually improving the efficiency and efficacy of mass transfer between gas and liquid.The variation of hydrate formation rate and storage capacity is studied in static pure water, pure water with stirring, for kinds of surfactants solution and surfactants solution with stirring systems.The promoting mechanism is analyzed from mass transfer. The results showed that hydrate formation rate in system of pure water with stirring is effectively improved but the storage capacity improve not obviously compared with in systems of surfactants solution and surfactants solution with stirring. The reason that surafactants can promote hydrate formation is related to its amphipathicity and ability to adsorb at metal surface. As the surfactants HLB value increase, hydrate formation rate improved but storage capacity decreased slightly. Hydrate formation rate can be further improved in system of surfactants solution with stirring.
The optimal dehydration rate of two cylindrical cyclone separators were compared under the water cut of 95%, 90%, 80% and 70% at the inlet, by changing oil-water mixing flow rate and split ratio. The experimental results show that when the inlet water cut is 95%, 90% and 80%, the optimal dehydration rate of the cylindrical cyclone with orifice vortex finder is 12%~22% higher than the cylindrical cyclone without orifice vortex finder. And the pressure drop between the inlet and the overflow increases 3~52 kPa. When the inlet water cut is 70%, the optimal dehydration rate of the former has little difference with the latter, but the maximum pressure drop between the former and the latter is 68 kPa. Under different experimental conditions, the pressure drop between the inlet and the underflow is not obvious, and the former is slightly higher than the latter. At the same time, when the inlet water cut is constant, the relationship between the optimal split ratio and oil-water mixing flow rate is consistent with the dehydration rate.
In order to evaluate the influence of ultrasonic cavitation on mixing, based on the method of UFD (User Defined Function), the flow field in the mixer（KSM）was numerical simulated by using FLUENT software and verified by experiment. The results showed that the fluid in the KSM mixed faster and more uniform due to the ultrasonic cavitation. The pressure drop of the mixer increased slightly. The flow rate of the fluid increased from 0.50 m/s to 0.55 m/s at the inlet of the mixer and it increased by 10%. The turbulence intensity of the fluid was enhanced, and the strengthening effect was most significant at the first mixing element. And more important, the strengthening effect was most significant for the first element which is basically stable after second mixing elements. The result of experiment also is basically consistent with the simulation results. The fluid mixed more uniform and the mixing was better. With the addition of ultrasonic cavitation, the mixing of the fluid in the static mixer was more uniform and the mixing effect was better.
In order to study the local mechanical properties of pipeline's defects, taking X70 pipeline as the research object, based on the knowledge of elasticplastic mechanics, ANSYS is applied to simulate the distribution near defects of Von Mises stress and plastic strain under the action of high temperature. Then the variation tendency of the maximum stress and plastic strain of key parts near defects with the increase of internal pressure is analyzed. Also, the variation trend of the maximum Von Mises stress with the corrosion depth under the specific operating pressure is discussed. Finally, the Von Mises stress distribution and variation considering and without considering the temperature expansion are compared. The results show that there is a greater stress along the circumferential direction in the corrosion zone at high temperature. With the increase of internal pressure, the maximum Von Mises stress decreases first and then increases, and the greater stress also becomes axial distribution. ASME B31G1984,ASME B31G1991,PCORRC and DNVRPF101 methods are still suitable for evaluating the residual strength of pipelines under high temperature.
