Interface tension reducing agent, preparation method and application thereof, and oilfield sump oil dehydration treatment method

The invention relates to the technical field of oil field environment protection, in particular to an interfacial tension reducing agent, a preparation method and application of the interfacial tension reducing agent and an oil field sump oil dehydration treatment method. The preparation method comprises the following steps: sequentially adding a dry and anhydrous catalyst, octamethylcyclotetrasiloxane and triethanolamine into a reaction kettle according to a required proportion, carrying out primary reaction for a period of time under stirring, vacuumizing the reaction kettle, and continuing the reaction under a vacuum condition to obtain an interfacial tension reducing agent, namely triethanolamine alcohol amine modified siloxane. According to the method, the interfacial tension reducing agent is added into the complex sump oil to realize rapid separation of crude oil from silt, mechanical impurities and oilfield chemical additives, then the organic acid modified phenolic resin type demulsifier is used to r