Quantitative and Qualitative Study of Water Wells in Cathodic Protection System of Gas Pipelines

Cathodic protection using an anode is one of the common methods for preventing the corrosion of metals in the oil and gas industry. In Golestan province, in some cities, the ground bed has been used for cathodic protection. In this research, with a monitoring method and using a novel- research tool, 14 anodic water wells in the cities of Golestan Province were investigated and the water of wells was analyzed. The breakage of the well wall, broken rope, irregularity of cables, and ground drift were observed at the well`s internal. Water hardness varied from 800 to 5200 ppm, chlorine from 5 to 86, and current from 0.21 to 3.6 in different wells. Wells No. 3, 11, and 12 have a pH lower than 6.5 and therefore have an acidic environment that is prone to corrosion. Wells 1, 4, 5, and 6 had TDS higher than 3000 mg/l, wells 1 to 3 had high water hardness, and the sodium adsorption ratio in well No. 6 was reached 23 indicating saline-sodium soil. Most wells also had low electrical conductivity. Based on the results of this research, it has become clear that during the design and operation of the anodic wells, soil characteristics, the probability of penetration of detergents into water wells, and other environmental issues should be considered. Moreover, It is suggested that the chemical and electrical properties of water and wells should be measured the during annual inspections and, that a standard be established in this field.