The influence of acetate ion on the rate of corrosion of carbon steel (X65) in 3 % NaCl brine saturated with carbon dioxide has been investigated using voltammetry at a rotating disc electrode. The rate of corrosion can only be understood if it is recognised that the cathodic process in the steel corrosion is affected by acetic acid.
An analytical approach that can discriminate between various forms of microscopic corrosion initiation has been employed in natural gas gathering and storage facilities. Information provided by the analysis of electron microscope coupons has led toward the better understanding and diagnosis of the initial stages of internal corrosion in natural gas gathering and storage facilities.
Electrochemical corrosion rate probes have been constructed and tested along with mass loss coupons in an air plus water vapor and a N2/O2/CO2 plus water vapor environment. Temperatures ranged from 200º to 700ºC. Results show that electrochemical corrosion rates for ash-covered mild steel are a function of time, temperature and process environment.
A laboratory flow loop is used to evaluate the ability of an on-line, electrochemical, biofilm-activity probe to monitor biofilm activity in synthetic oilfield brine and correlate its activity to localized pitting corrosion. In addition, bio-traps containing porous polymer beads for trapping biomass are evaluated as a rapid means to evaluate biofilm community structure.
This paper will consider the performance and relevance to static situations of the key types of Cathodic dip painting (CDP) Antifoulings (Rosin Modified types), the current tin free polishing types (typically acrylates of various types), and low energy surface types. Both field experience and laboratory work will be considered.
The NORSOK M-506 is an empirical model based on experiments undertaken in a single phase water flow loop. The data is from experiments with low content of iron ions in the water phase, and the model is thus regarded to give a fair representation of the maximum corrosion rate in a CO2 corrosion controlled system.
The tendency of pipeline girth weld coatings to shield cathodic protection (CP) current was studied in the laboratory. Epoxy, epoxypolyurethane, polyurethane, and wax were investigated. Results showed that the liquid coatings, when applied extra thin to accelerate the kinetics of absorption and current transmission, all disbonded by blistering, and all allowed CP current to be transmitted.
The literature has been reviewed with respect to information gained in the recent 20 years on CO2 corrosion of materials used in the oil and gas industry. The paper discusses the effect of materials related, medium-related and interface-related parameters on general (uniform) and localized corrosion. Part II
Stress Corrosion Cracking in the weld and heat affected zones of Duplex Stainless Steels has been experienced in different industries. In this paper, an attempt has been made to study the various aspects of this type of corrosion, brought about by welding. Results show duplex stainless steel base metal is also susceptible.