海上稠油油藏丰富，开采前景广阔。但火驱开采环境恶劣，难以保障安全开采。为研究固井系统的完整性，基于Mohr-Coulomb准则、力学理论和温度场分布，计算固井第一界面微环隙。考虑非均匀地应力、井下高温和地层温度共同作用对套管-水泥环-地层组合系统的影响，获取第一界面微环隙分布图。结果表明：井下温度、水泥环弹性模量、水泥环泊松比、水泥环热膨胀系数以及水泥环导热系数对固井第一界面的微环隙均有影响，通过调整水泥石的参数可以提高固井设备的安全性。

Offshore heavy oil reservoirs are abundant, with broad development prospects. However, the environment of fire flooding is harsh, so it is difficult to ensure safe exploitation. In order to study the integrity of cementing system, based on the Mohr-Coulomb criterion, mechanical theory and temperature field distribution, the first interface micro-annular of cementing was calculated. Considering the effects of non-uniform in-situ stress, downhole high temperature, and formation temperature on the casing-cement ring-formation combination system, and obtain the distribution diagram of the first interface micro-annulus. The results show that downhole temperature, elastic modulus of cement ring, Poisson's ratio of cement ring, thermal expansion coefficient of cement ring, and thermal conductivity of cement ring all have an impact on the first interface micro-annular of cementing, and the safety of cementing device can be improved by adjusting the parameters of cement stone.