Influence of gamma radiation on the treatment of sulfate reducing bacteria in the injection water used for the enhanced oil recovery

Abstract EN

The counts of sulfate reducing bacteria (SRB) in the water samples collected from the well head (formation water) and outlet of petroleum treatment plant (Produced water) in a petroleum field in middle delta- Egypt were determined.

The data showed a low count of (SRB) in the collected formation water sample and there was an obvious increase in the bacterial counts which appeared in the produced water, that may reveal that the presence of appropriate conditions for the growth of (SRB) in the closed system in treatment plant.

Two scale inhibitors were tested through jar test, the scale inhibitor I had maximum efficiency at 20 ppm, two SRB biocides were screened for their bactericidal activities.

It was found that the biocide A was slightly superior in respect to the antibacterial efficacy compared to B in presence of 20 ppm scale inhibitor.

These biocides were test for the study of the combined treatment with gamma radiation to maximize the efficiency on sulfate reducing bacteria using the minimum effective dose of both radiation and biocides to eliminate the negative impacts of the chemicals used and the radiation applied.

The results demonstrated that, the lethal doses of biocides were (300 ppm) of biocide A or (400 ppm) of biocide B at 1kGy irradiation dose.

The treated produced water was evaluated in respect of enhanced oil recovery, the data showed increase of the recovery capacity by the irradiation and chemical treatment.

This technology could be used for the water that are injected into reservoirs, and suitable for oil field and pipeline operators, and presented a viable bacteria control method.