Fracturing is one of the main facilities for increasing oil and gas wells. Fracturing is the use of high-pressure pump fracturing fluid injected into the formation, the formation of cracks and the expansion of new cracks and fill proppant, thereby enhancing the permeability of the formation. After the fracturing process equipment is determined, the effect of fracturing is mainly determined by the fracturing fluid. Early fracturing fluid is the gasoline as a dispersion medium, adding a certain viscosity of the fluid, which is the earliest oil-based fracturing fluid. This was first used in oilfield around 1948’. After that traditional water-based guar gum fracturing fluid was developed to adopt more complicated conditions like deeper well, a wide range of temperatures and higher viscosity request. While there are some disadvantages of Guar gum fracturing fluid, like high content of undissolved substance and residue, incompletely breaking. All these would easily cause formation damag...

Treatment of natural water and sewage is closely linked to preservation of the environment and is thus an actual present day problem. During the last decades there have been noticed substantial increase of the content of heavy metals, mineral oil, poorly-oxidable organic compounds, synthetic surfactants, pesticides and other pollutants from insufficiently treated effluents of industrial and municipal enterprises in open water reservoirs. In spite of the great number of elaborations reported in literature, the problem of natural  water and sewage treatment  has not yet been solved. Hence, the technology of water treatment needs further perfection which mainly includes the ways of intensive use of reagents, in particular flocculants. For these purposes water-soluble high-molecular compounds among which the most widespread and universal are polyacrylamide flocculants are used. As a result of their application the efficiency of removal of heavy metals is increased by 95%, compound...

The amphoteric polyelectrolyte is a kind of polyacrylamide with product chain not only the carboxyl anion charge, but also the vinyl cation charge. Therefore, an irregular copolymer of zwitterionic ions with both positive and negative charges on the molecular chain is formed. Amphoteric polyacrylamide is formed by hydrolysis and copolymerization of cationic and anionic groups. The advantage is that it has the characteristics of general cationic flocculants. It is used to extract ore from strong acid or recover valuable metals from acidic catalyst containing metal. Zwitterionic type is not a mixture of anionic and cationic type. If the combination of cationic polyacrylamide and anionic polyacrylamide is used, it will react to precipitate. So the bisexual ion product is the most ideal. Zwitterionic polyacrylamide, because of its cationic group and anion group, has the characteristics of general cationic flocculants. The combination of cationic polyacrylamide and anionic polyacrylamide...