1Scimitar Production Egypt Limited, Cairo, Egypt.
2WorleyParsons Engineers Egypt Limited.
3Chemical Engineering, Cairo University, Giza-Egypt.
4Petroleum Engineering, Cairo University, Giza-Egypt.
5Petroleum Engineering, Cairo University, Giza-Egypt.
An Egyptian Microbial Enhanced Oil Recovery (MEOR) project evaluated the degree of corrosion action which may result, on the production tube and casing and surface equipment, during the using of bacteria to improve the ultimate recovery in oil fields.
The high resolution metal loss technique and several standard coupons of the carbon steel were used to evaluate the level of corrosion of the bioproduct of these bacteria. The coupons were chosen to have the same material as that of the casing, the production tubes and the other surface facilities that may be used during the different phases of the MEOR project.
Four solutions that are used during the project phases were examined. The first solution is the sea water solution, which is used to preflush the reservoir. The second is a mixture of the nutrient and the sea water, which is used to incubate the bacteria inside the reservoir. The third one is the bacterial solution (a mixture of sea water, nutrient and the bacteria) that is injected into the reservoir in case of the incubation of bacteria outside the reservoir. The fourth solution is the effluent fluid that comes out from displacement tests on a pilot model which simulates the process of the MEOR. This effluent solution includes bacteria and its metabolism, nutrient, formation water, sea water, and oil.
The results showed that sea water and nutrient solution has the lowest rate of corrosion while the effluent from the model has higher corrosion rate than the third solution of sea water, nutrient and bacteria. The most corrosive solution was the sea water. These results indicate that the presence of Pseudomonas Aeruginosa and its bio products do not represent a high corrosive media for the equipment used in the MEOR project. Resulting photographs by binocular microscope show that the occurrence of corrosion under the bacterial growth is a function of the bacterial type. It was found that some of species of bacteria cause minimum corrosion. This study contributes to the successful application of MEOR process.
