Abstract:Since the breakthrough of deep natral gas exploration in well 1 of Qingshen gas field, Daqing oilfield has stepped into the stage of both oil and gas exploration and development. For the low drilling technical level, only 123 wells were completed during 2004—2010 with average well depth 4118m and drilling cycle 141d. Since 2011, by using the experience of speed increasing technology for deep drilling both in China and abroad, and based on the rock features, the speed-raise countermeasures were worked out. By the well structure optimization, high-efficient PDC bits selection and independent-research on new tools, deep drilling level was greatly improved. During 2011—2013, 19 wells were completed with everage depth of 4075m, drilling cycle was shortened 48.6d. According to the existing well head pressure, the causes were analyzed with a series of technical research; the matching cementing technology of gas channeling prevention was formed to provide the support and guarantee to increase reserve and production of deep natural gas.