Preparation
Oil-soluble nano iron 1%-10%, naphthenic acid 5%-25%, barium naphthenate 10%-30%, polyisobutylene succinimide 5%-10%, long chain fatty acid 1%-5 %, and the balance is solvent. The preparation method of Barium naphthenate is as follows: adding cobalt naphthenate, barium naphthenate, oil-soluble nano-iron and long-chain fatty acid to the solvent in sequence at normal temperature according to the proportion, and then adding polyisobutylene succinimide and stirring evenly to get Barium naphthenatet.