The raw product extracted from the wells in the sea or on the land are brought to refineries through pipes or by tanker ships for purification, distillation and decomposition. Here in those plants they are processed both physically and chemically. Depending on the processing, it is possible to obtain a different product, or sometimes even more than one product. These are basically petrochemical raw materials and fuel products. The yield of every well, or even sometimes the yield from a single well has different conditioning properties. However, since it is required to obtain the final product always be the same, it is desired to have the same result from different inputs. Furthermore, while trying to achieve this, we don’t want to waste the byproducts coming out during this process. Therefore, oil and gas extraction can be regarded as the crossroads of science and art.
As aforementioned, in order to have the extracted product to be fuel or ready-to-use plastic, it needs to travel to distillation and decomposition plants. Petrol / Gas extraction equipment, transferring pipes and distillation processes are highly expensive investments. While petrol / gas plants are being founded, they are planned to be working for long, long years. The main material of these plants are metal. When it comes to metals, the very first issue to be taken naturally into consideration is rusting. Since the material has different factors to cause rust, it is very crucial to prevent the materials from rusting. In order to achieve that a rust preventer (corrosion inhibitor) must be used. Mainly water based or grease based corrosion inhibitors are used. The corrosion inhibitors we provide as concentrated are mixed with different chemicals during the final product stage and released into the pipelines.
Contrary to traditional iron rust, rust on a petrol field is somewhat different due to metals having a different reaction with oxygen. The out coming fluids usually have a decreasing effect on the free oxygen. Generally soft steel is used on the lines, and when acid vapor in the extracted petrol gets in contact with the soft steel used in the pipe lines, rust happens. To make it clearer, for the corrosion there should be electrified clusters. Petrol causes electric voltage while running through the pipes. During the electrical interchange, iron is corroded and it gets rusted. Cathodic reaction gives electron to the fluid. On the anode side iron ions cause rust.
Generally, we can talk about two types of rust. First of these is the “Sweet Corrosion” which is a result of carbon dioxide or carbon acid. It could also be named as “sulphur-free rust”. The second type is the kind of rust created by the hydrogen-sulfide. It is also named as “Sour Corrosion”. It might also be called as “sulphurous rust”.
Under circumstances with high pressure and high temperature (which increase the reaction activity), dissolved carbon dioxide (exists as carbon acid) level increases and that causes sulphur-free rust. Carbon acid might get into reaction directly with iron based surfaces. However, with correct channelization it can be turned into a protective hydroxide film layer. However, if this layer disappears corrosion continues and it damages the metal in the form of evenly-shaped pores. It’s a less harmful type of rust compared to sulphurous rust. Hence getting the name of “Sweet Corrosion” as it is used in Turkish language.
It’s a more harmful type of rust. Hydrogen-sulfide
(H2S) directly gets into reaction with the metal surface and the iron-sulphur
protective layer might become the source of corrosion. This type of rust is a
result of hydrogen diatomization. Hydrogen atoms penetrate into the metal
surface and causes blistering, making the metal brittle and fragile.
Hydrogen-sulphur can also become a nest for sulphur decreasing bacteria. These
bacteria is mostly active in the storage section and they cause excessive
corrosion.
Rust is prevented by the continuous dosing of rust
preventers (corrosion inhibitors). These chemicals prevent rust by conditioning
the electrical fields mentioned earlier. Positive charged wetting agents are
connected to the negative charged pipe surfaces. Through these wetting agents,
hydrophobic surfaces happen. The exact translation for hydrophobic cold very
well be “not loving water”. These surfaces make the fluid transition behave
just like lead. The fluid cannot get the surface wet during transfer and rust
is prevented. We have various types of rust preventers (corrosion inhibitors).
These are listed below.
1.
I. Water Soluble Rust Preventers (Corrosion
Inhibitors)
2.
II. Oil Soluble Rust Preventers
3.
III. Oil Soluble Water Dispersible Rust
Preventers