In most of the corrosive well-operating environments, the expected life exceeds 20 to 30 years. Titanium is very durable, corrosion-resistant, and in other industries like seawater coolers in nuclear power plants and chemical industries, it is the metal of choice for high corrosion resistance.
Carbon fiber is strong and nearly inert to corrosion bar wet/temperature degradation over time. CRA-tubulars apply a safety factor to the operating envelope. The (initial) operating limits are the limits CF would have after degradation.