SELECTION CASING MATERIAL DEPENDING OF WELLS FLUID CORROSIVITY

Abstract

World production of pipes is mainly based on the standards of API. However, this does not obligate you to use exclusively for casing manufactured by API standards. The wells that will exploit the hydrocarbons and aggressive media, install the protective casing made of alloy steel not yet covered by API standards. Running  casing operation holds a special place in all phases of the wells because of protective casing  account for a high percentage of the cost of drilling and improperly designed pipe string (or damaged by corrosion) increased costs due to repair of the object. If the fluid layer which produce, present aggressive gases (CO₂, H₂S, Cl), under certain thermodynamic conditions, it may cause significant corrosion of pipe materials. That created openings in the casing string may allow migration of gas. For this reason it is necessary to know the limits specified partial pressures of gases and estimate conditions in which corrosion is expressed.