| 摘要 |
A process for displacing a fluid through a well and/or a permeable subsurface formation communicating with the well, by injecting into the well an aqueous solution which contains, as viscosifier, a heteropolysaccharide comprising glucose and, for each 7 moles of glucose, 0.9-1.2 moles of galactose and 0.65 to 1.1 moles of pyruvate, together with succinate and acetate in molar proportions (based on 7 moles of glucose) between 0 and 2. The heteropolysaccharide is suitably obtained by cultivation of a slime-forming species of Pseudomonas, Rhizobium, Alcaligenes or Agrobacterium, in particular Pseudomonas NCIB 11592. |
