Abstract: With the further exploration in Dagang Oilfield, the buried hill reservoirs become more and more important. Such conditions, as complex geology, deep buried depth, high temperature and high pressure, low formation pressure coefficient, and multiple formation pressure systems, make it more difficult for drilling plan and site operation, and such troubles as blowout, lost circulation, pipe sticking and hole collapse are likely to happen. Some study programs are carried out for solving these problems, include 1.prediction of formation pore pressure, formation collapsing pressure and formation fracturing pressure; 2.optimization of deep well casing program; 3.investigation on the influencing factors of pressure loss in deep well; 4.use of downhole motor to improve ROP in deep well; 5.study on the rock mechanics in deep well drilling. Applying these technologies, Deep well drilling performances have been improved and the cost cut down a lot, and a great breakthrough in oil and gas exploration has been made in the buried hill of Qianmiqiao area.