Emulsifier and preparation method therefor, and oil-based drilling fluid

Abstract

Described are an emulsifier and a preparation method therefor, and an oil-based drilling fluid. The emulsifier has a polyene polyamine skeleton and a hydrophobic group connected to the skeleton, and part of the polyene polyamine skeleton is connected to a sulfonic acid group. The molar ratio of a sulfur element to a nitrogen element in the emulsifier is 0.02-0.4:1. In the emulsifier, the part of the emulsifier that does not contain the sulfonic acid group can function as a main emulsifier, and the part of the emulsifier that contains the sulfonic acid group has suitable hydrophilicity and can function as an auxiliary emulsifier. A composite emulsifier formed based on compounds of the same structure and type can achieve closer fusion to form a compact composite interfacial film, and has an excellent emulsifying effect and good electrical stability and thermal stability.

Dependencies are inferred from the claim text.