Advanced Materials Research Vols. 361-363

Abstract: Minimum Miscible Pressure (MMP) is among key parameters to predict CO₂ flooding performance during candidate reservoirs screening process. In this paper, key factors determining MMP are screened after investigation over previous researches, and then by seven samples of oil component, a reasonable empirical function is developed to predict MMP for reservoirs in China, of which coefficients are calculated by genetic algorithm (GA) to improve accuracy for further application. After comparison, it proves better prediction by new function than the ones already existed, which can be widely used for further MMP prediction for pilot reservoir in China.

Abstract: The new technology of composite perforation, which combines together the conventional perforation and the high energy gas fracturing, can effectively increase the hydrocarbon production and improve the enhancement of the oil/gas recovery. In recent years, the composite perforation technique has been widely used worldwide. However, this technology was not used extensively in Chinese oil filed because its research on the combustion characters of propellant is rare and the corresponding optimal perforation design is not practical. Based on a comprehensive analysis of the propellant’s burning features, we establish a new combustion model for the propellant used in composite perforation, which takes into account that the combustion consists of the cylinder layer burning and circular burning along the perforation tunnels. Using the actual well data from oilfield and the conventional parameters of domestic propellant, we use this new model to perform numerical simulations and analyze in detail the process of related pressure change. The simulation results are accordance with the actual data from field operation, which further confirms the reliability of the model. The established model can provide better references for the optimum design of composite perforation.

Abstract: For the design and management of the modern heavy oil piplines, the application of mathematical model to describe the characteristics of screw pump is crucial to the improvement of design quality and operational management efficiency. According to the features of HOW7T.3(50mm) screw pump’s actual measured data, this research established two groups of mathematical model.The first one described the change of screw pump’s displacement along with the variation of pressure difference and viscosity, while the second group described the change of shaft power along with the variation of pressure difference and viscosity, and then it solved all the four models by a particle swarm optimization (PSO) algorithm. The model-building and model-solving of these two examples showed that the PSO algorithm could rapidly search the best model regression parameter. Through the four target test, the research finally selected two models with relatively high accuracy. In the end, the paper put forward that it is necessary to take further research on the forms of screw pump characteristic mathematical model, and the corresponding optimization method of model-solving, in order to make the models more succinct and with higher fitting precision.

Abstract: By detecting the axial strain at the near-bit, we can obtain the weight on bit(WOB), however, some other factors in the well such as hydrostatic force, circulating pressure, may also affect the measurement. Unless take these factors into consideration, derive the correction formula for the measurement data of WOB, eliminate the impact of other forces, we may not obtain the actual data of the weight on bit.

Abstract: Paper analysises active regulation of microwave to heavy oil by experiment and theory. Determine heavy oil’ rheological indicators before and after . test the composition and structure of heavy oil by the chemical analysis tools, before and after the role of the microwave, analysis the cause of rheological change. Based on the theories of electromagnetic field and the thermodynamic, Establish the mathematical model of microwave effect on heavy oil, determine the experimental temperature distribution inside the heating chamber, and further analysis the mechanism of microwave on heavy oil. Also introduced field application of single-well oil pipeline microwave heater which was development by experiments and theory research. Experimental and theoretical analysis shows that the microwave effect on heavy oil, both have thermal effects and non-thermal effects. Field application shows that microwave is feasible used in heating pipeline in theory, field trials are successful.

Abstract: The treatment of oily wastewater by microwave radiation is highly-efficient, low contaminative. In order to improve the effect of processing oily wastewater with microwave radiation, the influence of the ionic property, the ionic valency, the ionic concentration and microwave parameter are investigated by experiment. The results show that inorganic salt promotes demulsification under microwave radiation condition. The lower the ionic valency is, the better the deoiling effect is. The deoiling rate increases in a certain range with concentration of inorganic salt increasing, and it also has the optimum microwave parameters. When oily wastewater is disposed by microwave radiation after adding inorganic salt, the deoiling rate is up to 97.78%

Abstract: The chitosan-mediated synthesis of porous nanosized NiB alloy catalysts could be achieved by silver-catalysed electroless plating (EN). The unsupported and supported NiB-CS catalysts with particle size of ~25 nm were produced. The as-prepared catalysts exhibited superior catalytic activities in p-chloronitrobenzene and sulfolene hydrogenation to those of the NiB catalysts.

Abstract: Solvent extraction technique is one of the cheapest and most efficient processes experienced in recycling of used lubricating oils. In this paper, the performance of furfuryl alcohol in recycling used vacuum pump oil was evaluated experimentally. The effect of the most critical parameters (solvent to oil ratio, and extraction temperature) was investigated. The results show that viscosity index and refractive index of refined oil was related to the solvent to oil ratio. Viscosity index and the refractive index come to a reasonable value at 90°C when solvent to oil ratio equal to 1.5. The difference of IR spectrum of the used vacuum pump oil and re-refined vacuum pump oil show that absorption peaks at 1745cm ^{– 1} and 1160 cm ^{– 1} disappeared after solvent extraction.

Abstract: Polymer-free VES fluids are used to minimize damage to the proppant pack to efficiently transport proppants into fractures. Proper investigation of the rheological properties and the proppant settling of the fluids play an important role in fracturing enginering.In this paper,the rheology and viscosity-temperature properties of the VES fracturing fluid were researched at the range of 1wt% to 6wt% of VES concentration using the HAAKE RS300 Stress-Controlled Rheometer. Proppant settling experiments are performed in static VES fluid. The results show that VES system behaves as a non-Newtonian shear-thinning fluid and the power law model can be used to describe fluid rheology within a certain range of shear rate and temperature. However, with the increase of shear rate and temperature, the fluid trends to Newtonian fluid. Apparant viscocity of the fluid first increases slightly with the temperature rising from 28°C, then，It would drastically reduce after reaching a peak. The temperature correspongding to the peak value increases with the concentration of VES,as well as the shear rates. When VES concentration is 4wt%, the fluid may generates stable micro-mesh wormlike micelle structure, which results in good viscoelasticity and high proppant-carrying capacity.

Abstract: The pyrolysis of three oil samples from Tarim Basin was carried out under 390°C and high pressures formed by injecting N₂ in the closed system and the influences of temperature, time and the oil compositions on the pyrolysis reaction of oil to gas were discussed. The gas generation ratio increased and average activation energy decreased with the content of polar compositions in oil, and the gas generation ratio changed intensively with reaction time for high content of polar compositions under the experimental conditions. The effect of pressure on pyrolysis of oil was tightly related to oil composition. High pressure was beneficial to the pryolysis of oil with more polar compositions. The calculated value of the gas generation ratio fitted well with experiment value as the parallel first order reaction model containing 11 reactions with different activation energies and different preexponential factors was used for simulating the pyrolysis reaction of oil to gas by minimizing objective function with MATLAB optimization module.