MICROBIOLOGICAL METHOD OF SULFUR AND NITROGEN CONTENT DECREASE IN PETROLEUM AND HYDROGEN SULFIDE IN DEPOSIT WATERS AND CASING-HEAD GASES Russian patent published in 1999 - IPC

FIELD: technical microbiology, ecology. SUBSTANCE: method involves contact of an aqueous suspension of bacteria with petroleum or other medium to be treated. Bacteria Thiobacillus denitrificans, Thiobacillus aquaesulis or Thiosphaera pantotropha or any their combinations adapted to deposit conditions and petroleum are used. Adaptation of bacteria of these species to hydrocarbons is carried out preliminary by culturing bacterium strain on petroleum-containing media. Process is carried out in depths in situ under anaerobic conditions directly. Suspension is pumped into the layer out at bacteria concentration 10⁴ cells/ml of suspension, not less, and process is carried out at 25-50 C and pH 6-9. In salted layers and at temperature above 50 C treatment is possible. Method can be used for treatment of casing-head gases and deposit waters. Ratio of treatment - up to 10 times. Dilution of petroleum alleviates petroleum output. EFFECT: enhanced effectiveness of petroleum and attendant media treatment. 6 cl, 3 ex