5. External Pipeline Corrosion

External pipeline corrosion is casaude by

2. Internal pipeline corrosion

2.1. General

Internal corrosion in pipelineInternal pipeline corrosion is a common problem when there is addiquate concentration of CO₂ or H₂S in the well fluids. 

The most widely used methods to prevent internal corrossion are the following:
1. Chemical injection: Inject corrosion inhibitos () in the well fluids

2. Corrosion Resistant Alloys (CRA): This is the most common sulution. Instead of using Carbon steel pipes we use stainless steel or ... pipes. Compare to chemical injection the use of CRA has a higher initial cost, however there is no operational cost and the system has a high reliability

3. Corrosion allowance: providing extra wall thickness during design in order to act as a corrosion allowance in case of temporary failure in the chemical injection system
 

2.2. Corrosion Perdiction

The degree and extent of corrosion can be calculated using corrosion models such as NORSOK M-506, de Waard 1995, and IFE top-of-line corrosion. The models are cable of identifing arean along the pipeline where corrosion is likely to occur and the effects of CO2 corrosion.

2.3. Corrosion Monitoring