Abstract: To improve the capability of Shenli field to drill Extended Reach Horizontal Wells, and to prepare the work of offshore oil production from land, the key exploration well of Gaoping-1 is drilled in Gaoqing zone of Jiyang depression. Through the measures of optimizing wellbore scheme, mixing drilling fluid properly, and planning operation parameters, the difficulties of adding weight on bit, returning cuttings, high tripping friction, running horizontal casing, and controling the trajectory are overcome. The well is 4535 m deep, 3462.07 m long of the lateral section, and 3814.32 m long of horizontal reach. The intermediate casing is 244.5 mm as diameter, and 723 m as horizontal section length. The maximum ratio of horizontal to vertical reach is 4.02. The operation processing and drilling fluid are illustrated in detail, which would be an direction for the operation on the well of the same type.