RISK OF THE UNDERGROUND STEEL STRUCTURES BIO-CORROSIVE PROCESSES ASSESSING METHOD Russian patent published in 2018 - IPC G01N17/00 G01N33/20 

FIELD: transportation.

SUBSTANCE: invention relates to the field of pipeline transport, in particular, to the bio-corrosion studies under laboratory and field conditions on the pipelines outer surface and the soil bio-corrosive aggressiveness assessing in the main oil pipelines and oil product pipelines (MNPP) laying areas, taking into account the most significant environmental factors affecting the microbiocoenosis formation. Risk of bio-corrosive processes in underground steel structures assessing method is characterized by the fact that determining the humidity in the soil, the soil mineral composition, soil specific electrical resistance (SER), soil oxidation-reduction potential (ORP), soil pH, total number of the aerobic bacteria (AB), total number of the micro fungi (micromycetes) (MF), individual classes of microorganisms, sulfate reducing bacteria (SRB), iron bacteria of bacteria (IB), after which the soil aggressiveness coefficient (SAC) is calculated by the formula: K_SAC=K_M*K_B*K_EH*K_ES, where K_M is the coefficient taking into account of the soil mineral composition, which is calculated by the formula: K_M=K_SO4*K_CO3*K_Cl*K_S*K_Fe, where K_SO4 is coefficient taking into account of the sulfate ions content; K_CO3 is coefficient taking into account of the carbonate ions content; K_Cl is coefficient taking into account of the chlorine ions content; K_S is coefficient taking into account of the sulfides content; K_Fe is coefficient taking into account of the iron content, where K_B is coefficient taking into account of the main groups of microorganisms content, which is calculated by the formula: K_B=K_SRB*K_IB*K_AB*K_MF, where K_SRB is coefficient taking into account of the sulfate-reducing bacteria content; K_IB is coefficient taking into account of the iron bacteria content; K_AB is coefficient taking into account of the aerobic bacteria content; K_MF is coefficient taking into account of the micro-fungi (micromycetes) content, where K_EH is coefficient taking into account of the soil electrochemical parameters, which is calculated by the formula: K_EH=K_pH*K_ORP*K_V, where K_pH is coefficient taking into account of the pH effect; K_ORP is coefficient taking into account of the redox potential magnitude; K_V is coefficient taking into account of the soil moisture amount: where K_ES is coefficient taking into account of the soil electrical resistivity value, at that, depending on the measured indicators values, to each of the K_M, K_B, K_EH, K_ES, K_SO4, K_CO3, K_Cl, K_S, K_Fe, K_SRB, K_IB, K_AB, K_MF, K_pH, K_ORP, K_V coefficients a value from 1 to n is assigned, and the risk of the soil bio-corrosive aggressiveness is determined by the K_SAC coefficient value.

EFFECT: enabling the soils bio-corrosive aggressiveness assessment in the underground pipelines laying area based on the soil bio-contamination and its mineral composition comprehensive analysis.

1 cl, 6 tbl