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The research status of thixotropy at home and abroad was reviewed, including thixotropy classification, thixotropy model and thixotropy measurement. Thixotropy refers to the behavior that the viscosity of Non-Newtonian fluid changes with shear time at a certain temperature・ The research on thixotropy mechanism and thixotropy model will help people to have a deeper understanding of the thixotropy of materials, which is conducive to the promotion and application of thixotropy materials; secondly, the common thixotropic agents such as fumed silica, organic bentonite, hydrogenated castor oil, polyamide wax and so on were summarized・ A brief introduction was given to the rheological modification principle of thixotropic agents in the system and their application in polymer materials. With the continuous deepening of research and development, thixotropic agents have been widely used to improve the rheological properties of polymer materials such as coatings, paints, adhesives, etc., effectively improving material storage stability, workability, etc; finally, the research and development trends of thixotropy and thixotropic agents are summarized and prospected・ The application fields of thixotropy continue to expand, and the development of thixotropic agents continues to be diversified and efficient. [ABSTRACT FROM AUTHOR]

Self-cleaning mechanical screen is the main sand control method for completing wells in polymer flooding sand formations. The selection of seam type should not only ensure the ideal sand control accuracy, but also minimize the impact on the performance of chemical drive solutions・ The viscosity loss rate of polyacrylamide solution through the screen was investigated using a small visual sand control simulation experiment equipment. The effects of each screen slit type，pumping speed and solution viscosity on the viscosity of the polymer solution were evaluated・ The result showed that the experiments yielded a viscosity stabilization time of 1 h after the polymer solution was configured・ The rate of viscosity loss decreased as the fluid pumping rate increased・ The effect of solution concentration on viscosity under the same conditions is less and the recovery time is shorter・ The study considers the shear damage to fluid by common self-cleaning screen slits, and proposes a new manipulable experimental method for evaluating the performance of polymer flooding screen, which provides a reference for the preferential selection of mechanical sand control structure for well completion with polymer injection. [ABSTRACT FROM AUTHOR]

Shell 90 # base asphalt and waste tire rubber powder are selected as the main test materials, and the penetration, viscosity, ductility and softening point of asphalt are taken as the indicators to evaluate the performance of rubber asphalt. The preparation temperature, rubber powder dosage, rubber powder mesh, mixing mode, heat storage mode, heat storage time and microstructure of rubber asphalt are studied in depth. The results show that the influence of preparation temperature on rubber asphalt is complex; When the mesh number of rubber powder is less than 30 and the content of rubber powder is less than 20%, the penetration of asphalt produced by shear method is greater than that by mixing method; The softening point of asphalt produced by mixing method is higher than that of asphalt produced by shear method, and the viscosity of asphalt produced by mixing method is higher than that of asphalt produced by shear method under the conditions of different rubber powder mesh and different rubber powder content; The viscosity of rubber asphalt in static storage is much faster than that in dynamic storage. Finally, it is concluded that the prepared asphalt can be reheated for up to one time at the preparation temperature of 185 ℃ after mixing for 1h, and the storage time under the static hot storage condition is not more than 2h. The produced rubber powder asphalt has the best performance in terms of ductility, viscosity, penetration, softening point and other technical indicators. [ABSTRACT FROM AUTHOR]

In order to develop new formula for capsule. k-Carrageenan, gellan gum, arabic gum, gelatin and KC1 were used as raw materials for capsule wall materials for cigarettes. The effects of the above raw materials on the dripping process and capsule quality were analyzed, and the forming process of dropping pills was discussed. Based on the evaluating standard of quality of capsule, the orthogonal test was performed. The proper formula is determined as follows: the adding amount ratio 2:1 of k.carrageenan and gellan gum, the addition amount of gum Arabic, gelatin, and KC1 are 4%,4% and 6%, respectively. After one month of manufacturing basing on the formula, the average qualified rate of capsule diameter, pressure value and appearance are 98. 7%, 98. 3% and 97. 6%, respectively. Fragrance has better releasing effect. It occupies the value of industrialized application. [ABSTRACT FROM AUTHOR]

The removal of residual boron ions and metal ions in a fracturing flowback fluid in Ordos were investigated by used the cross-linking-precipitation method.The influence of three kinds of boron removal agents on cross-linking-precipitation method to study.The results showed that PVA-124 had the best boron removal effect. The response surface optimization experiment was carried out on the basis of single factor, and the process conditions were optimized: boron ion∶polyvinyl alcohol-124（molar ratio） 1∶15, pH of 10, reaction time of 30 min.The performance of the base fluid prepared by the treated water was evaluated, and the results showed that the viscosity, pH, shear resistance and gel breaking performance of the base fluid were all satisfactory, the requirements for the secondary dosing are met. [ABSTRACT FROM AUTHOR]