As was noted earlier, oil producers confront, primarily, two major problems causing complications in the operation of wells, oilfield equipment, and distribution pipelines that require urgent solution.

 First problem involves the protection from corrosion, while the second one involves the need of removing ARPD and mineral depositions.    

   Let us consider the corrosion problem.

    The corrosion of metal oil-and-gasfield equipment and distribution pipelines occurs under the influence of mineral salts and corrosive gases, such as hydrogen sulfide, carbon dioxide, hydrogen chloride, and oxygen dissolved in oil-field and bottom water, and due to the effect of possible corrosion stimulated by the action of microorganisms and certain chemical reagents fed into well. 

   This slide presents the main types of corrosion of oil-and-gasfield equipment: 

- pitch corrosion in the form of separate caverns;

- point or pitting corrosion in the form of a set of local point damages;

- intercrystalline corrosion spreading between the metal crystals; 

- fretting corrosion that causes the formation of pits, etc. on contact surfaces in stationary detachable connections of oil and gas equipment (for example, connections of strings of pump-compressor pipes (PCP)  and pump rods, rotor wheels with shafts of centrifugal pumps, threaded connections, etc.);

- corrosion cracking that represents the formation of corrosion cracks due to hydrogen saturation, corrosion fatigue of metal, and the effect of tension stresses (for example,  PCP strings).