In the light of the problems with normal methods of placing a whipstock in a side tracked hole, Model CYY443- 146 packer and matching setting and releasing string are improved.

• 一般的导斜器靠水泥固定，尾管支撑，施工麻烦，作业时间长，且不能在套管任意位置固定和开窗侧钻。