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.

Polyvinyl chloride (PVC) is generally used for phthalate plasticizers, because of its high plasticizing efficiency. These phthalate plasticizers will cause the problems of durability, toxicity and potential carcinogenicity, they can make service life shorter, endanger human and animal health. So it has been gradually replaced by the new type of plasticizer. Polyester plasticizer is a kind of green environmental protection plasticizer and can better solve the disadvantage of traditional plasticizer, so it was widely studied at home and abroad. In this article, plasticizing mechanism(Lubricity theory, Gel theory, Free volume theory), selection criteria, synthesis and classification of the polyester plasticizer are introduced. The polyester plasticizer is mainly divided into two categories:biological polyester plasticizer and petroleum polyester plasticizer.

The three dimensional flow and mass transfer mathematical model of oilwater flow in the soil around underground pipeline is built using the finite volume methodo. The ground temperature change in different locations is numerical simulated by the CFD software when oil pipeline leaks in winter and the range of oil distribution in the soil. The simulation results show that there is a stable temperature field around the pipe before leak, while the changed of temperature fields and the oil distributions are different under three conditions after leak.

The nonuniform solution exhibited as waterinoil suspension or emulsion produce for the admixture of oil and waterbased viscosity depressant, which brings some potential difficulties to the measurement of viscosity and thus evaluation of viscosity depressants. Agitating method is employed to solve this problem at present. However, this method can't well mimic the effect of pipe flow shearing on rheological behavior of wateroil blend due to the difference in agitating strength from limitation of experimental design. As a result, the evaluation result from this method is generally too far optimistic. For this reason, an improved evaluation method for the performance of waterbased viscosity depressant was proposed, which can simulate the shear and thermal conditions tightly as in a real field. The experiment results reveal that the method has a better performance and provide a solid basis for evaluation for waterbased viscosity depressants. 

Currently,more and more engine blocks are produced by cast aluminum alloys in automotive industry.For the poor wear resistance,cylinder liners made of gray cast iron are embedded to improve the tribological properties.A promising alternative to the use of cylinder liners is the application of wear-risistent coatings deposited by thermal spraying onto the cylinder bore walls.The two kinds of iron-based coatings were prepared by arc spraying.The microstructure and wear risistance of the coatings were analysed by OM,SEM,XRD and MMW-1 Vertical universal wear tester and chosed gray cast iron as a standard material for comparison.The wear tset was carried out under lubricated sliding conditions,sliding speed of 0.5m/s,sliding distance of 4500 m,and normal load of 200 N.The results show that,08A coating has satisfactory values of wear and friction and that it can be a substitution for gray cast iron liners.