There are two reasons why the oil casing pipe is stuck:
One is sticky suction card;
The second is the collapse of the well wall or the sand bridge stuck.
After the oil casing is stuck, it can be fully pressed but cannot be lifted. The annular gap between the casing and the well wall is small, and it is impossible to mill undercuts.
1. Adhesion suction card
Under the circumstance that the drilling fluid can be circulated, inject the stick-relieving fluid to release the sticking, which is the same as the method of dealing with sticking sticking.
2. Collapsing or sanding
(1) Sand bridges have been formed in the well, but some drilling fluids are still returned. The small displacement and low pump pressure circulation should be adhered to, the viscosity of the drilling fluid should be increased, the cutting should be increased, and the wells should be cemented after returning to normal circulation.
(2) The oil casing has been lowered to the bottom of the well, and leakage occurs when collapse or sand jam occurs. Analyze the lost layer, and quickly cement the well to squeeze the cement slurry into the lost layer.
(3) If the oil casing is not down to the bottom of the well, but it is not far from the target layer, cement the well first, then drill through the cement plug and casing shoe, and circulate the well to the end. Adopt the method of hanging tail pipe to seal the oil and gas layer well.
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