Corrosion is one of the most costly flow assurance problems in the industry, costing the oil and gas industry $1.4 billion per year. Tomson Technologies has considerable expertise on corrosion research and testing. Tomson Technologies routinely performs journal publication level research and expert testing on various topics related to corrosion in the oil and gas industry.
Tomson Technologies has studied a large number of field applicable materials ranging from carbon steel to stainless steel to numerous corrosion resistant alloys. Tomson Technologies has tested these materials at reservoir conditions for their resistance to both uniform and localized corrosion. Tomson Technologies created and continuously expands a large material selection database, useful over a wide range of specific reservoir conditions.
State of the art equipment and techniques are used to evaluate corrosion in the laboratories. Both weight loss and electrochemical techniques are used to evaluate uniform and localized corrosion at temperature and pressure conditions. Corrosion inhibitors performance can be tested by analyzing both uniform and localized corrosion under various temperatures, scale species, corrosion products, CO2 partial pressures, brine chemistry, and alloy materials.
A custom autoclave for high pressure high temperature corrosion measurements is used in the lab to evaluate the corrosion mechanisms and rates. We have the capability to perform Linear Polarization Resistance Measurements at high temperature and high pressure. Tomson has evaluated various materials in the autoclave to incorporate into the material selection guide for the oil and gas industry. Our autoclaves can be setup in different configurations depending on the need.
In the Rotating cage autoclave (RCA), the coupons are placed in a rotating cage inside of the autoclave and exposed to the temperature and pressure conditions for the desired period of time. After exposure, the corrosion rate is determined based on weight loss and 3D optical spectroscopy with vertical scanning interferometry (VSI).
Linear polarization resistance (LPR) is an electrochemistry technique to monitor corrosion rate in-situ, it uses three electrodes to create a cell and monitors the coupons response as it corrodes. Tomson uses LPR to monitor corrosion rates in the autoclave.
Tomson uses a corrosion glass cell setup to evaluate corrosion in cases where the temperature and pressure are not of concern. The glass cell can be operated up to 90°C and is useful for screening corrosion inhibitors or materials. The coupons can be static in the glass cell and the solution is stirred, or alternatively, a rotating cylinder electrode (RCE) setup can be used with the glass cell to increase the shear stress that the coupon is exposed to. The analysis of the corrosion rate can be done in situ via LPR or via weight loss after the test is done.
Flow through corrosion
A custom HPHT flow-through apparatus has been developed in house to investigate corrosion in a flow regime under strictly anoxic (<< 1 ppb O2), high temperature and high-pressure conditions. The autoclave is limited in the pressure that it can hold and therefore Tomson developed a high pressure corrosion flow loop to evaluate the corrosion under more representative conditions.
3D Optical Microscopy with Vertical Scanning Interferometry (VSI)
Localized corrosion can be the issue of concern, especially when CRA (corrosion resistant alloys) are used in the industry, and especially in deepwater production. Traditional corrosion rate measurements do not differentiate between general and localized corrosion. A novel technique using VSI has been
developed at Tomson Technologies to measure localized corrosion in a non-destructive, fast and accurate method. VSI generates a 3D image of the surface where pits can be readily quantified.