According to the classification method of oilfield chemicals, surfactants for oilfields can be classified into well-drilling surfactants, surfactants, surfactants for increasing the yield, surfactants for oil and gas gathering, and water treatment. Surfactants and so on.
(1) Surfactants for drilling. Among the surfactants used in the oil field, the amount of surfactant used for drilling (including drilling fluid treatment agent and oil well cement admixture) is the largest, accounting for about 60% of the total amount of surfactant used in the oil field; It is relatively small, but its technical content is relatively high. Its amount accounts for about 1/3 of the total amount of surfactant used in the oil field. These two types of chemicals occupy an important position in the oil field surfactants.
(2) Surfactant for oil recovery. Compared with the surface active agent for drilling, there are relatively few kinds and quantities of surfactant for oil recovery, especially for some acidification and fracturing products.
(3) Surfactants for oil and gas gathering and transportation. The research, development and use of surfactants for oil and gas gathering and transportation in China began in the 1960s. There are currently 14 types and hundreds of products. Among them, the largest amount of crude oil demulsifier, the annual need for about 20,000 tons. Our country has developed suitable demulsifier products for different oilfields. Many varieties have reached the international level in the 1990s; there are fewer varieties such as pour point depressants, flow improvers, viscosity reducers, and paraffin inhibitors, and most of them are Compound type products, due to the different nature of the crude oil used for the lowering of coagulation, flow improvement, viscosity reduction and cleaning wax for the purpose of the surfactant different requirements, but also for the development of new products put forward higher requirements and difficulties.
(4)Oil field water treatment surfactant. Oilfield water treatment agent is an important category of oilfield chemicals used in oil development. The annual dosage of various water treatment agents is over 60,000t, of which the surfactant accounts for about 40%, despite the fact that surfactants are used in oilfield water treatment. The demand is large, but there are few studies on surfactants for water treatment in China. The types of surfactants used in oilfield water treatment are not complete yet, and most of the products are imported from industrial water treatment industry, but due to oilfield water Due to the complexity, the products introduced directly from industrial water treatment have poor applicability, and sometimes they do not work. There is also a lack of targeted oilfield water treatment surfactants.
(5) Surfactant for tertiary recovery. Foreign tertiary surfactants have stable quality and large scale of production. China has already formed some surfactants and polymer varieties for flooding, but it still cannot meet the needs of tertiary oil recovery. The annual production of heavy alkylbenzene that can be used as a surfactant for synthetic oil-dispersing agents is less than 20,000 tons. It is difficult to meet the needs, and the molecular weight and molecular weight distribution are not suitable for surfactants for synthetic oil-dispersing agents; Although a lot of work has been done on surfactants, it still cannot meet the needs of oilfield flooding, and there are problems with the scale of production and product quality.
