Patents Assigned to National Iranian Oil Company
  • Method for recovering oil from an underground formation
    Patent number: 4364431
    Abstract: Method for recovering oil from an underground formation consisting of blocks of relatively low permeability with an oil-wet pore space containing oil surrounded by a fracture network of relatively high permeability by supplying to the fracture network an aqueous solution of a surfactant adapted for decreasing the surface tension between water and oil and displacing the oil from the oil-wet pore space of the blocks.
    Type: Grant
    Filed: December 17, 1980
    Date of Patent: December 21, 1982
    Assignees: National Iranian Oil Company, Shell Internationale Research Maatschappij B.V.
    Inventors: Ali M. Saidi, Frans T. Hesselink