Abstract: The G0-7 3D horizontal well group is planned in the southeast part of Sulige Gasfield of Changqing Oilfield, composed by 1 straight well, 2 directional wells, 2 conventional horizontal wells and 4 3D horizontal wells. The factory drilling operation was adopted – three rigs started drilling at the same time and each drilled one conventional well and two horizontal wells. In view of difficulties in drilling of cluster well group, a series of measures were formulated in terms of anti-collision and avoiding barriers, wellbore profile optimization, wellbore trajectory control, reducing friction and drag, and special techniques were developed like ‘pre-split’ anti-collision and avoiding barriers, 3D well profile optimization, 3D well wellbore trajectory control and CQ-SP2 drilling fluid system, etc. The penetration rate of this cluster well group was 9.68 m/h in average, up by 18.19% on year-on-year basis, and average drilling period was 55.67 d, shortened by 8.82% compared with the original drilling mode. The successful factory drilling operation of this well group provides a strong technical support for factory drilling operation of 3D horizontal wells planned by Changqing Oilfield.