<p>Offshore heavy oil production is transitioning from steam flooding to in-situ combustion (ISC). To accurately evaluate the risk boundary of the combustion-zone casing section in injection wells during the ignition-combustion process, a dynamic risk assessment framework is proposed by integrating a time-dependent Kriging model with stress-strength interference theory. Thermo-mechanical finite element simulations are first conducted, alongside high-temperature tensile and creep tests on TP110H casing steel, which is widely used in offshore thermal recovery wells. These tests are performed over a temperature range from ignition to peak combustion temperatures to characterize the temperature-dependent mechanical behavior of casing materials under ISC conditions. A Kriging model is then constructed to extrapolate these data and characterize material behavior under continuously varying bottom-hole temperatures. Subsequently, Monte Carlo simulation is employed to sample random operating conditions, and the dynamic casing failure probability is evaluated using stress-strength interference theory. The results indicate that the failure probability of the combustion-zone casing section remains below 0.1% within the temperature range of 400–500 °C, but increases sharply to 34.66% when the temperature exceeds 500 °C. The proposed framework provides a practical approach for casing risk assessment under extreme high-temperature conditions and offers theoretical guidance for casing material selection, safety threshold determination, and completion strategy optimization in high-temperature production wells.</p>