Short term corrosion monitoring of carbon steel by bio-competitive exclusion of thermophilic sulphate reducing bacteria and nitrate reducing bacteria
MetadataShow full item record
Recent interest has centred on the application of nitrate injection to control reservoir souring. In the present study, the impact of nitrate injection on the corrosion of ASTM A572-50 carbon steel was evaluated. The steel samples were exposed to corrosive production water (high chloride and sulphate) for 21 days at 50 °C. Crude oil and NaNO3 were added as bacterial nutrients. Indigenous bacterial isolates were used and four different conditions were evaluated: control cell (no bacteria), nitrate reducing bacteria (NRB) inoculated cell, sulphate reducing bacteria (SRB) inoculated cell and mixed bacteria (NRB + SRB) inoculated cell. Open circuit potential (Ecorr) and Electrochemical impedance spectroscopy (EIS) were employed to monitor the corrosion process throughout the immersion time. It is shown that the corrosion rates in the cells inoculated with bacteria are lower than the control cell. Both NRB and SRB may offer beneficial corrosion protection to the steel. However, the microscopy results show that localized corrosion in the presence of bacteria is inevitable. Additionally, nitrate promotes the growth of NRB and suppresses the growth of SRB; hence H2S production can be eliminated. NRB oxidize the produced sulphide by SRB and maintain Eh in an inhibitory level to SRB.
Showing items related by title, author, creator and subject.
Investigation of the impact of nitrate injection to control sourcing problem in oil reservoir : benefit and side effects on steel materialsHalim, Amalia Yunita (2011)The successful control of reservoir souring by nitrate injection has been well documented in the literature. Recent interest has centred on how nitrate application can increase the corrosion risk in pipelines and metal ...
Preliminary study on nitrate injection to control souring problem in oil reservoir: Benefits and side effects on steel material (UNS S31603)Halim, A.; Gubner, Rolf (2011)Nitrate injection is a common approach used to control reservoir souring. This method relies on nitrate reducing bacteria (NRB) ability to suppress sulphate reducing bacteria (SRB) growth. These experiments were conducted ...
Preliminary study on the benefits and side effects of nitrate injection on pitting corrosion of UNS S31603Halim, A.; Gubner, Rolf; Watkin, E. (2011)Biogenic production of H 2S in oil reservoir (souring) by sulphate reducing bacteria (SRB) is a serious concern for the oil industry. Nitrate injection has been widely used as an approach to control this problem. This ...