Abstract: The No.4 Island at Kendong Block 12 of Shengli Xintan Oilfield is a group of long reach cluster wells for producing offshore oil from onshore. The formations are complex, and there are many holes that need anti-collision and avoid obstacles, and well trajectory control is demanding, so the overall drilling operation is of great difficulty. In line with the above drilling technical difficulties, some key technical measures were used, such as orientation of shallow large wellbore, control of wellbore trajectory, anti-collision and avoiding obstacle and optimization of drilling fluid. All the 20 wells are up to the design requirements; the deviated wells were successful in one time orientation and target hit rate was 100%. The technology is very effective and provides experiences for overall development of offshore reservoirs by long reach cluster well groups.