SẢN PHẨM THƯƠNG MẠI HÓA
In the oil and gas industry, equipment and structures always operated in severe corrosive environment. A corroded structure for example oil platform is very dangerous which resulting in great damages and losses in both lives and money. To avoid such losses and damages, it is necessary to give out solution that help to safeguard these equipment and structures from corrosion.
Protection of metal from corrosion to increase the lifetime of structures is a very important issue. There are several ways that can protect structures from corrosion:
Select the right materials that are durable in the working environment;
Using corrosion inhibitor;
Select and using suitable durable coatings;
Cathodic protection system (using sacrificial anodes …).
Among these, cathodic protection by using sacrificial anodes method is a very effective and easy way to carry out. This protection method has been standardized to protect steel structures in underground and underwater environments, which are used extensively in the oil and gas industry. The anode is made from a metal alloy with a more negative electrochemical potential than the metal of the structure it is protecting (the cathode). To protect the corrosion, Sacrificial anodes are coupled to the structure under protection. Electrical capacity of the sacrificial anode is demonstrated by the electro current that it provides per unit volume (A.h/kg)
Principe of cathodic protection by using sacrificial anode or impressed current
Nowadays, aluminum alloy anodes are the most widely used as they have superior electrochemical and mechanical properties that allow them working in high temperatures and harsh environments.
Base on the demand for aluminum alloy anodes and with the aim of providing the market with high quality products gradually replacing imported products, VPI carried out the research on "Studying to improve the process of manufacturing aluminum alloy anodes meeting international quality standards" which is divided into two phases.
Phase 1: Completion of production technology of aluminum sacrificial anode for equipment and structure in oil and gas industry (Implementation time: 12 months, 2011).
Phase 2: Production of aluminum sacrificial anode meeting international quality standards (Implementation time: 12 months, from 6/2014 to 6/2015).
As the result of the research, VPI successfully fabricated Aluminum Alloy Sacrificial Anode. Electrochemical and mechanical properties of the anodes are improved. Great electrochemical capacity allows them to survive in long period of time and work well in high temperature and strong corrosive environment.
The electrochemical capacity of VPI anodes is 2640 – 2660 A.h/kg equivalent to product of world 's leading companies. Meanwhile, the electrochemical is just more than 2300 A.h/kg according to TCVN 5741Vietnam Standard, and more than 2500 A.h/kg according to the ISO 15589-2, DNV RP B401 international standard. Anode with high electrochemical capacity allow for efficient protection of electrical currents with low amount of anode that help to increased working life of the anode and economic efficiency.
The quality of sacrificial aluminum alloy anodes manufactured by VPI has been certified to meet the international quality standard by QUATEST 1 and DNV. In addition, VPI Anode has also been tested in the laboratory and the field at Vietsovpetro Joint Venture with very good results, confirming its quality in protecting marine structures.
II. TECHNICAL SPECIFICATION OF VPI ANODE
1. Electrochemical Properties:
2. Chemical element:
3. Shape, dimension and net weight:
Shape, dimension and net weight of the anodes can be modified to match with the requirement of the End-users.
4. Other specification:
The surface is smooth and no crack.
Anode has the same quality from the center to the surface, good electrical contact between core and anode body to ensure the electrical conductivity and mechanical property.
Anode dissolves evenly in sea water, not passive.
All other specifications shall satisfy fully anode quality requirements complying in ISO 15589 and DNV B401 standards and customer's requirements.
Aluminum alloy sacrificial anodes are used to protect petroleum metal structure from corrosion especially marine structure such as platform, underwater pipelines, ships…
The images hereunder describe how they are applied with different objects.
Platform (Trapezoidal anode)
Ships (Straight flat anodes)
Note: Dimension, type and specification of the anode can be fabricated according to clients’ requirement.
IV. QUALITY OF VPI PRODUCT IN COMPARISION WITH IMPORTED ANODES
Quality of VPI Anode in comparison with imported product: