The liner cementing under high temperature and high pressure in slim-hole is difficult. Well Long-16 is an important preliminary prospecting well in Chuanbei low and flat fold belt of Jiulongshan structure. The original 2159mm hole was designed to complete in Permian, but as well kick and circulation loss happened frequently, 1778mm casing was put down to cement the upper well section ahead of schedule. In this case, 1492mm bit was used to 598800m, and liner cementing was completed. Before cementing, oil gas showed strongly with drilling fluid density of 234g/cm3 and well temperature of 1396℃.