1, casing running, cementing and waiting for setting;

2. Remove the connection between the bottom casing head and the replacement cross, and install the bop stack;

3. On the flange of the bottom casing head, two wooden boards are placed horizontally to support the hanger assembly;

4. Lift the casing, the tonnage of which shall be 1 15% of the weight of the free section, so as to generate tension of 40-50Kn, and the tonnage force of which shall be105%-10% of the weight of the free section;

5. Align the guide locating pin of the separated casing hanger, keep the lower handle fixed, rotate the casing hanger by 90 degrees with the upper handle, take down the handle one by one from bottom to top, remove the wooden board, make the hanger assembly sit on the shoulder of the casing head, hold the casing, and then loosen the casing; Observe 1 hour to observe the setting.