Oil casing is mainly used to transport oil and natural gas from the bottom of the well to the surface and plays a vital role in the drilling process. Today, Union steel will introduce you to the oil casing operation technology in detail.

1) Preparation before placing casing:

1. Check whether the floating shoes, floating hoops, variable buckle joints, graded hoops, double male joints, mushroom heads, undercut joints, and top joints can be used normally, whether the threaded buckles are qualified, and conduct a trial connection on the ground.

2. Prepare casing data according to the requirements of the casing laying notice. The casing data should be matched in three ways, namely matching with Party A’s data, matching with the site sorting number, and matching with the remaining casing quantity.

3. Check and prepare the tools used to run casing: casing clamps, casing elevators, casing lifting belts, casing sealing grease, grouting lines, wellhead mud lines, “big caps” to protect the box, etc.

4. Check and replace the 5 1/2-inch ram core, take out the wear-resistant sleeve, place the circulation joint on the drill floor, place the circulation joint and emergency joint on the drill floor, and run the casing when the ordinary port does not return mud. When the clamp overflows, connect the kelly Pipe and emergency joint quickly. (Note: Each time you connect an accident joint, you must first connect the accident joint to the casing, and then connect the kelly to prevent the kelly from breaking the casing thread)

5. Throw away the rat hole and replace it with a clean casing rat hole.

6. Two mud pumps. One pump is equipped with a 170*1 cylinder liner for jacking, a 170*2 cylinder liner is used for circulation (replace the mud if necessary), and the other pump is equipped with a 160*3 cylinder liner for solidification wells. , large displacement circulation after reaching the well.

2) Casing operation

1. The hoisting pipes should be hoisted one by one. When hoisting, pay attention to the conditions of people around you. Standard lifting straps must be used.

2. The drill floor protection lines are strung together with ropes and lowered with a pneumatic winch. It is strictly prohibited to throw directly to avoid injury.

3. When connecting accessories, be sure to apply sealing grease to prevent damage caused by incorrect buckling.

4. During the casing running process, when the operation is stopped due to equipment maintenance, casing replacement, mud filling, etc., the casing should be moved up and down to prevent the casing from getting stuck.

5. When tightening the casing clamp, it must be aligned before tightening. It is strictly forbidden to force makeup after making mistakes. The buckling torque meets the standard requirements. After buckling incorrectly, check whether the buckle is damaged. If there is any problem, throw it away and replace it. If the buckle torque reaches maximum and three or more buckles are still present, remove the sleeve and replace it. If the buckle is tightened and tightened twice, the maximum torque is still not reached. , the casing comes off and is replaced.

6. The speed should be controlled during the casing running process. The running speed of each casing should not exceed 30 seconds to prevent formation leakage.

7. It is required to grout 10 pieces at a time, which must be filled every time; the casing must be moved during grouting to prevent casing accidents. Grouting must continue after the casing enters the stable section. It is strictly prohibited to use mud pumps for grouting to prevent pipelines from being thrown out and injuring people. (In special circumstances, if a mud pump is used, the protective rope or protective chain must be tightened)

8. During the casing running process, a dedicated person must be on duty to observe whether there is leakage (the mud will not leak). There is no backflow after running the casing) and overflow phenomenon (the mud flows back after the casing is not running).

9. After the shell is installed, check whether the number of remaining shells is correct.

10. After placing the casing, grout once and then start the pump. The casing must be moved when filling with mud.

11. The threaded button of the fixed sealing mushroom head should be in place and should be placed in the center when lowered into the wellhead to prevent scratching the rubber of the mushroom head.

12. After running the casing, first set the seal and check whether the gate switch is correct, then start the pump to circulate through the side diversion. After the circulation is normal, cement the well.

13. Basic principles:

(1) If the thread is not clean, it cannot be screwed on; if the casing number is incorrect, the elevator will not be able to lift; if the elevator is not tightened, it will not be lifted;

(2) The buckling should be stable to prevent cross-tying; the wellhead operation should be careful to prevent falling objects inside and outside the casing; drill in large quantities; fill mud according to regulations to prevent the casing from being crushed; unified command must be unified when running casing to prevent the casing from being crushed. damage and injuries, and ensure safe construction.

3) Abnormal situation handling and preventive measures

1. When encountering resistance, it is strictly forbidden to lift or press hard. Carry out mud circulation immediately, open the small displacement jacking valve, and then conduct large displacement circulation according to the changes in pump pressure, and record the changes in pump pressure and suspended weight.

2. If jamming occurs, the casing should be moved immediately and the lift should not exceed 5 tons to prevent damage to the casing due to instability of the soft rod. After gluing, immediately report to the resident staff and company supervisor whether oil soaking is needed.

3. If overflow occurs, the well should be shut down immediately, the circulation joint should be connected, the well should be reported to the personnel stationed in the well and the company supervisor, measures should be taken to kill the well, and the casing operation should be continued after the gas layer is stabilized.

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