Shaft bottom leakage-proof plugging system and method for cementing well with same

Abstract

The invention discloses a shaft bottom leakage-proof plugging system and a method for cementing a well with the system, and belongs to petroleum drilling and well cementation construction operations. The system is composed of an upper connector, a lower connector, a casing pipe and a casing shoe, the upper connector is connected with the lower connector, and the casing pipe and the casting shoe are arranged on the upper connector and the lower connector respectively. In the well cementation process, when the system is arranged down to the well, after the casing pipe is down to a preset depth, a ball is put in, the ball reaches the second step face of a valve seat barrel, pressurization is carried out in the valve seat barrel, a rubber sleeve expands due to pressure and extrudes a well wall, fixed sealing and isolation is achieved, then pressurization is carried out further, a shear pin is shorn, the pressure pushes the valve seat barrel to move to the first step face, a bypass hole of the upper connector is exposed out, cement paste is poured in through the upper end of the casing pipe, flows out of the bypass hole, and is filled into the space between the well wall and the casing pipe, the normal well cementation operation is carried out, the poured-incement paste in the well cementation process can be prevented from being leaked through a well bottom leakage layer, the smooth well cementation operation is guaranteed, well cementation quality is guaranteed, and the system is simple in structure and convenient to mount.

Description

technical field [0001] The invention relates to an oil drilling cementing construction operation, in particular to a well bottom leakage prevention and plugging system and a cementing method using the system. Background technique [0002] In cementing operations in petroleum, geological drilling and other fields, after drilling to the designed well depth, it is necessary to run the casing into the well, and inject cement from the inner cavity of the casing, so that the cement flows into the bottom of the well, and then flows out of the casing into the casing and Between the well walls, the continuously entering cement gradually rises until the entire space between the casing and the well wall is filled from bottom to top, so that the casing and the well wall are fixed together to strengthen the well wall. However, due to leakage in the formation at the bottom of the well or improper operation when running the casing into the well, the pressure is excited and the well formati...

AI Technical Summary

Problems solved by technology

However, due to leakage in the formation at the bottom of the well or improper operation when running the casing into the well, the pressure is excited and the well formation is lost.

Cause cement to flow out from the leakage layer after entering the bottom of the well, resulting in cement not being able to fully flow between the casing and the well wall, affecting the quality of cementing or causing cementing failure

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