Processing method for perennially polluted sludge containing oils and water, waste residues or oil sands deep in natural oil mines, and processing system thereof

A processing method for perennially and deeply polluted sludge containing oils and water, waste residues, or oil sands in natural oil mines, comprising the following steps:

• (A) allowing a solid substance containing oils and water to be in full contact with an organic liquid solvent with a low boiling point and a weak polarity or no polarity at room temperature under pressurized condition to extract oil by the solvent from the solid substance containing oils and water to the liquid, to obtain a deoiled solid and a solvent-oil-water mixture, wherein the solid substance containing oils and water is perennially and deeply polluted sludge containing oils and water, waste residues, or oil sands in natural oil mines;
• (B) performing solid-liquid separation on the obtained deoiled solid and solvent-oil-water mixture;
• (C) performing gasification separation on the solvent-oil-water mixture obtained after the solid-liquid separation to separate the organic solvent with a low boiling point and a weak polarity or no polarity for recycling;
• and
• (D) performing oil-water separation on the oil-water mixture obtained by the separation in step (C) to obtain extracted oil,
• wherein in step (A), the extraction temperature is −10-45° C., and the extraction pressure allows the organic solvent with a low boiling point and a weak polarity or no polarity to be kept in liquid state;
• and the organic solvent with a low boiling point and a weak polarity or no polarity is gaseous at room temperature and atmospheric pressure or has a boiling point below 25° C.