| 摘要 |
A method of abandonment of an oil well. Firstly, providing a cutting tool including a cutting head with radially extendable blades, a rotary drive unit capable of rotating the cutting head, and a connecting shaft extending from the rotary drive unit to the cutting head. Secondly, lowering the connecting shaft into an inner casing which is concentrically disposed within an outer casing of the oil well until the cutting head is positioned below a ground surface. Thirdly, rotating the cutting head with the rotary drive unit while extending the radially extendable blades on the cutting head and continuing to rotate the cutting head until an upper portion of the inner casing has been severed. Fourthly, withdrawing the cutting head and pulling out of the outer casing the severed upper portion of the inner casing. Fifthly, setting a plug in the outer casing with a plug setting tool to provide pressure containment. The plug is set below a desired cutting depth for severing the outer casing. Sixthly, reinserting the connecting shaft into the outer casing until the cutting head is positioned at the desired cutting depth for severing the outer casing. Seventhly, rotating the cutting head with the rotary drive unit while extending the radially extendable blades on the cutting head and continuing to rotate the cutting head until an upper portion of the outer casing has been severed. Eighthly, removing the severed upper portion of the outer casing and burying the outer casing.
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