Studies on the impact, detection, and control of microbiology influenced corrosion related to pitting failures in the Russian oil and gas industry. Final CRADA report.

Abstract

The objectives of the Project are: (1) to design effective anti-corrosion preparations (biocides, inhibitors, penetrants and their combinations) for gas- and oil-exploration industries; (2) to study a possibility of development of environmentally beneficial ('green') biocides and inhibitors of the new generation; (3) to develop chemical and microbiological methods of monitoring of sites at risk of corrosion; and (4) to evaluate potentialities in terms of technology, raw materials and material and technical basis to set up a production of effective anti-corrosion preparations of new generation in Russia. During the four years of the project 228 compounds and formulations were synthesized and studied in respect to their corrosion inhibiting activity. A series of compounds which were according to the Bubble tests more efficient (by a factor of 10-100) than the reference inhibitor SXT-1102, some possessing the similar activity or slightly better activity than new inhibitor ??-1154? (company ONDEO/Nalco). Two synthetic routes for the synthesis of mercaptopyrimidines as perspective corrosion inhibitors were developed. Mercaptopyrimidine derivatives can be obtained in one or two steps from cheap and easily available precursors. The cost for their synthesis is not high and can be further reduced after the optimization of the production processes. A new approach for lignin utilization was proposed. Water-soluble derivative of lignin can by transformed to corrosion protective layer by its electropolymerization on a steel surface. Varying lignosulfonates from different sources, as well as conditions of electrooxidation we proved, that drop in current at high anodic potentials is due to electropolymerization of lignin derivative at steel electrode surface. The electropolymerization potential can be sufficiently decreased by an increase in ionic strength of the growing solution. The lignosulfonate electropolymerization led to the considerable corrosion protection effect of carbon steel. More than three times decrease of corrosion rate on steel surface was observed after lignosulfonate electropolymerization, exceeding protective effect of standard commercially available corrosion inhibitor. Solikamsky lignin could be a promising candidate as a base for the development of the future green corrosion inhibitor. A protective effect of isothiazolones in compositions with other biocides and inhibitors was investigated. Additionally to high biocidal properties, combination of kathon 893 and copper sulfate may also produce a strong anticorrosion effect depending on concentrations of the biocides. Based on its joint biocidal and anticorrosion properties, this combination can be recommended for protection of pipelines against carbon dioxide-induced corrosion. By means of linear polarization resistance test, corrosion properties of biocides of different classes were studied. Isothiazolones can be recommended for treating oil-processing waters in Tatarstan to curb carbon dioxide - induced corrosion. A laboratory research on evaluation of the efficiency of biocides, inhibitors and penetrants by biological and physical-and-chemical methods has been carried out. It was shown that action of corrosion inhibitors and biocides strongly depends on character of their interaction with mineral substances available in waters on oil-exploration sites. It was found that one of approaches to designing environmentally safe ('green') antimicrobial formulations may be the use of synergetic combinations, which allow one to significantly decrease concentrations of biocides. It was shown that the efficacy of biocides and inhibitors depends on physicochemical characteristics of the environment. Anticorrosion and antimicrobial effects of biocides and inhibitors depended in much on the type of medium and aeration regimen. Effects of different biocides, corrosion inhibitors. penetrants and their combinations on the biofilm were investigated. It has been shown that minimal inhibiting concentrations of the reagents for the biofilm are much higher than those for aquatic microorganisms. Results obtained from the research in stationary conditions have been confirmed with data from experiments carried out in hydrodynamic conditions. New approaches to the investigation of biocorrosive processes on the basis of bioluminescent method of intracellular ATP determination have been developed. Approaches and methods developed on the basis of bioluminescent method could significantly simplify the analysis of biocorrosion processes and allow to conduct the analysis directly under the field conditions in situ. An express method to assess biogenic sulfate reduction in soil and water samples has been elaborated. The method intends for field application and allows one to no-problem assess action of such harmful and corrosion provoking microorganisms, as sulfate-reducing bacteria.