Risk Assessment of Annular Pressure Caused by Tubing Leakage in Offshore Gas Wells with High CO₂

Table 2

Characteristics and risks of different annulus starting pressure modes.

Number	Leakage point pore size	Leakage point depth	Maximum pressure value	Pressure rise rate	Pressure rise cycle	Accumulated gas volume	Risks
1	Big	Light (color)	High	Fastest	Shorter	Big	High
2	Small	Light (color)	High	Slow	Longest	Big	Medium
3	Big	Deep	Low	Soon	Minimum	Small	Medium
4	Small	Deep	Low	Slowest	Longer	Small	Low