In order to reveal the structural cause of the interfacial activity of petroleum carboxylate and further research the combination law of petroleum carboxylate with sulfonate,three fractions of Daqing crude oil with average carbon number of 23.16,26.01,28.70,respectively,were selected as the raw materials to prepare a kind of petroleum carboxylate whose average carbon number is close to the carbon number of sodium oleate.The interfacial activities of sodium oleate and the petroleum carboxylate were detected ...