Oil extn. by flooding with water - contg. glyco-lipid nonionic surfactants made by biosynthesis (NL 14.8.79)

摘要

Oil is displaced from rock formations or oil sands by flooding with aq. dispersions of non-ionic glycolipid surfactant made in two stages by (1) continuous or semi-continuous growth of micro-organisms in a mixt. of 1-35 vol.% hydrocarbons with an aq. inorganic nutrient soln. and opt. other growth materials of 20-50 degrees C and pH 3-9 with passage of air opt. enriched with O2, and (2) sepg. the glycollipid from the cell material by temp., pH or osmotic shock. The aq. phase is used directly as flooding agent or added to the flooding water, and the cell material, wholly or partly recycled to the culture medium. Pref. specific micro-organism strains are used to obtain glycolipids of known structure. The controlled conditions allow prodn. of glycolipids of optimum compsn. and structure, which increase the oil yield by flooding. The oil extrd. can be used as carbon source in (A), and formation water contg. >=10% salt can be used for sepn. by osmotic shock in (B). Recycling of cell material gives a saving in nutrient salts.