Novel hydraulic cutter device for cutting multi-layer casings

Abstract

The invention relates to a novel hydraulic cutter device for cutting multi-layer casings. The novel hydraulic cutter device for cutting the multi-layer casings is used for the deep-water wellhead wellabandonment operation. The wellhead casings are cut by the novel hydraulic cutter device, so that wellhead devices are convenient to recycle. According to the technical scheme, drilling fluid pushesa piston to move down, and then the piston drives a cutter to rotate around a pin, so that the cutter cuts the casings; when cutting of the cutter is completed, a piston circumferential through hole communicates with a limiting rod radial through hole, and at this time, the drilling fluid pressure has an obvious pressure difference, and whether the casing cutting is completed or not can be judgedaccording to the fluctuation of the drilling fluid pressure; and a blade supporting structure is additionally arranged on the end portion of the cutter to realize smooth recovery of a blade. The novelhydraulic cutter device for cutting the multi-layer casings has simple operation, whether the casing cutting or not is completed can be effectively judged, the cutting of the multi-layer casings withdifferent diameters can be achieved by adjusting the relative distance of pressure relief holes.

Description

technical field [0001] The invention relates to a novel hydraulic cutter device for cutting multi-layer casings, which belongs to the field of underwater wellhead casing cutting of offshore oil and natural gas. Background technique [0002] With the continuous development of offshore oil and gas, more and more oil and gas wells are approaching their service life and have lost their value for continued use. In order to prevent oil and gas pollution, if there is no other use for underwater oil and gas wells that have reached their operating years, they must be used in accordance with national regulations. The well abandonment operation is carried out on it, but the key technology in the well abandonment operation process is casing cutting. At present, the underwater wellhead casing cutting has the following problems: (1) It is impossible to effectively judge whether the casing cutting is completed; (2) After the casing cutting is completed, the cutter cannot be retracted smoot...

AI Technical Summary

Problems solved by technology

At present, the underwater wellhead casing cutting has the following problems: (1) It is impossible to effectively judge whether the casing cutting is completed; (2) After the casing cutting is completed, the cutter cannot be retracted smoothly; (3) It cannot continuously cut multi-layers with different diameters casing

The hydraulic cutters developed by Logan Oil Tools and Pioneer Oils Tools Limited abroad rely on the pressure generated by the drilling fluid to drive the cutters for cutting, which can complete the cutting of multi-layer casing at one time, and when the cutting is completed, there will be a significant pressure drop indicating that the cutting It has been completed, but the cutter blades of the two companies cannot be actively recycled into the cutter body

And domestic patent number CN201679464U a kind of hydraulic type inner cutte

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