Advanced Materials Research Vols. 781-784

Abstract: Abstract: In order to understand the relationship between the number of blade and the performance of the self-balance multistage centrifugal pump’s first stage impeller internal flow characteristics, Reynolds Navier-Stokes equation and κ~ε turbulence model are used for numerical simulation. The objects of numerical simulation are five self-balance multistage centrifugal pump’s first stage impellers, the blade number of them is 4，5，6，7，8.Under the rated flow ,the numerical simulation obtain five kind of impeller inner flow field distribution , Through the comparative analysis ,when the number of blade is 4,8,the flow of the impeller’s inner and pressure distribution become chaos ;And, the number of blade is 5,6,7, With the increase of blade number, the impeller internal flow are smoother，the head and efficiency are enhanced correspondingly.

Abstract: Based on the formation characteristics of high temperature (above130°C ) and multi-salt, we optimize several blowing agent monomers to compound a new type of foaming agent, and screen out the new foam stabilizer to determine the new ebonite foam drilling fluid system. In the laboratory, we evaluated its resistance to high temperature, salt and oil pollution. And we made a research on its rheological characteristics of the foam and the behavior of high salinity. The experimental result shows that the ebonite foam drilling fluid has much more foam, longer stable time, significant effect of the resistance to high temperature, salt and oil pollution and has good sand-carrying ability, which can effectively prevent the occurrence of loss circulation and meet the requirement of rock carrying and wellbore stabilization.

Abstract: Daniudi Gas Field reservoir has low degree of porosity and permeability, thus it is highly susceptible to the invasion of the solid phase of clay particles in the drilling fluid during the drilling process, in view of these problems, we introduce the non-clay weak gel drilling fluid system. Experiments of the drilling fluid system for rheological property, salt-resisting pollution, hot rolling rate of recovery, reservoir damage evaluation and drilling fluid treating chemical opimization have been taken. The experimental results show that the drilling fluid system has excellent temperature-resisting and salt-resisting character, good ability of suspending debris and strong inhibitory action, its rheological property can meet the needs of the long horizontal section of drilling engineering and the reservoir protection effect is excellent. In DP21 well horizontal section construction, each performance indicator of the drilling fluid can be controlled well and effectively solve the problems of cuttings carrying, borehole wall stability and reservoir protection, successfully completed the DP21 well drilling construction task.

Abstract: Based on the principle of hydraulics,an effective equipment of hydrodynamic cavitation is designed and built in this paper.The orifice plates with various geometry size were used as hydrodynamic cavitation generator to study the relation ship between many factor,such as,inlet pressure,discharge,flow speed in orifice,and the cavitation number.Analysis of water flow cavitation status for the experimental unit,this device can produce cavitation phenomenon.The methylene blue and spectrophotometer method can capture the free radicals generated successfully.This is an effective way to measuring the free radicals quantitatively in cavitation,moreover it is easy to fulfill.The intensity of cavitation increases with reduction in the cavitation number.By analyzing the influence of cavitation number on concentrations of •OH.It would be strength of hydrodynamic cavitation.The effect of operating parameters,such as inlet press,low speed in orifice and optimum the structure of hydrodynamic cavitation,best condition of the hydrodynamic cavitation is the inlet press、flow speed in orifice 14 m/s、 0.07.

Abstract: The influences of the pressure, temperature and pH on the property of reverse osmosis membrane Dow SW30 were investigated in self-designed equipment unit with hardness-removed seawater as raw material. The optimal process parameters were pre-compression pressure 3.5 MPa, operation pressure 3 MPa, the temperature of feed seawater 25-30°C, pH value 7-8 and feed flow rate 60 L/h. Under these conditions, the flux of reverse osmosis membrane SW30 kept stable for long-term operation, and its salt rejection rate was above 99.4%.

Abstract: Microbubbles play an important role in the micromixing of micro-fluidic systems. However, there are few results in the literature about the mixing of the liquids caused by bubbles flow. The paper presents the numerical simulation of bubbles flow in microfluidic, which agrees well with the experimental results. The influence of velocity amplitude, frequency and phase difference on the mixing performance was investigated. The results show that the isolate bubbles as obstruction can improve mixing efficiency in the true straight microchannel, the bigger the velocity amplitude, and the higher the frequency, the better the mixing efficiency is, but the mixing efficiency has nothing to do with the number of bubbles and just benefit from the certain phase difference. With the other two parameter remains unchanged, the mixing performance achieves the best value when the velocity amplitude is 0.25m/s, the frequency is 25HZ, the phase difference is 0.25, respectively. The study referring to bubbles flow induced mixing performance is very important for many microfluidic devices.

Abstract: Gas field scaling is an important factor affecting the normal production of the gas wells. Scaling problems have been come into being in many production wells of Songnan gas field. The paper carried on experimental study and reason analysis on the scaling problem of Songnan gas field. The result shows that the fouling is mainly composed of calcium carbonate. The mainly reasons for the scaling are the incompatibility between Cacl₂ killing fluid and formation water as well as the pressure reduction around the wells.