The research progress of rare earth metal-mediated group transfer polymerization (REM-GTP) is reviewed. The main features of this polymerization method, the polymerization mechanism and its application in the polymerization of vinyl phosphonates and other nitrogencoordinating monomers are introduced. The application prospect and developing direction of this kind of polymerization method are also forecasted.

At present, most of the main agent of conventional clean fracturing fluids are viscoelastic sixteen (or eighteen) alkyltrimethylammonium chloride, which has poor temperature resistance (generally less than 60 ℃). The quaternary ammonium salt type surfactant (JS-VES) based on high carbon chain erucic acid has good temperature resistance. In this paper, a high-carbon erucic acidtype clean fracturing fluid (mass fraction) (0.80% JS-VES+0.68%NaSal+2.60%KCl+0.40%Na ₂S ₂O ₃) was developed with JSVES as the main agent, and compared with the conventional clean fracturing fluid system performance. The highcarbon erucic acidtype clean fracturing fluid system (25 ℃, 170 s ^-1) has an apparent viscosity of 25 mPa•s. It has good shear resistance, and can meet the requirements of suspended sand in the static suspension of sand, with a good breaking capacity (2 mPa•s) and temperature resistance (80 ℃).

The transportation quantity of backward products in batch transportation of products often changed for some reasons, resulting in the changes of feature of mixed oil during batch transportation. To solve this problem, the governing equations of contaminated product were established based on multiphase flow model. Discrete numerical calculation were made with finitevolume method. The results show that the law of mixedoil’s feature variation is different with the quantity of backward products and among different periods. The increase of the transportation quantity of backward products can reduce the mixed volume, and when transportation sequence is different,the influence of changes of transportation quantity on growth rate of the mixed volume is also different.

n order to more accurately determine the crude oil batching transportation temperature fluctuation, the soil temperature field around pipeline insulation surface drift was studied. For variation characteristics of soil temperature field around underground pipeline in the process of batching transportation of cold and hot crude oil, the non steady heat transfer model was established, and soil temperature field in different period of batching cycles and moments was numerically simulated and analyzed by using CFD software in the process of crude oil batching transportation. The results show that the drift on the thermal insulation surface of soil temperature field has certain regularity, and adiabatic surface with crude oil batching transportation time shows periodic drift, drift period and period of batching cycles of cold and hot oil transportation were the same; drift cycle of thermal insulation surface of soil temperature field and the scope are related to cold and hot cycle on the batch transportation of oil.

Aiming at the mixed oil quantity of pipelining products, mixed oil control equations of batch transportation was established based on multiphase flow model and finite volume method. The transportation mediums were 0# diesel and 90# gasoline. The numerical calculation was based on two cases, the product flows through a Ztube from top to bottom and from bottom to top. The research shows that when it flowed through the horizontal section of a Ztube, the distribution of mixed oil is not symmetric. In a vertical section, there are lager amount of mixed oil when diesel is above gasoline and the distribution of section concentration was more uniform when gasoline is in front of diesel.

Due to the complexity of China's long-distance pipeline via regions, parts of the pipeline assume the big gap transportation inevitably. And dip angles and batch transportation both make great influence on mixed oil characteristics. Aiming at the issue, based on VOF multiphase flow model three-dimensional straight tube is the research subject to simulate numerically the dip angles and the batch transportation's influence on mixed oil characteristics respectively. The results show that the mixed oil concentration decreases gradually with the increase of the dip angle under the conditions of light oil first and heavy one trailing, and when the heavy oil is first and the light one is trailing, the concentration of mixed oil increases gradually as the angles increased. And in the case of heavy oil first, the characteristics of mixed oil is impacted greater by the angle.