Cement storage string and squeeze cement tool

Abstract

The invention provides a cement retention pipe column and a cement squeezing and injecting tool. The cement retention pipe column comprises a cement retention device and a setting device. The cement retention device comprises an expansion rubber barrel, an outer central pipe and a control part. The setting device comprises an inner central pipe and a sliding sleeve. When cement is squeezed and injected, the expansion rubber barrel is used for anchoring and sealing the squeezing and injecting pipe column in a barefoot well. Since a sealed inner cavity is formed between the outer central pipe and the expansion rubber barrel, along with increase of liquid in the inner cavity, the expansion rubber barrel is gradually expanded until the whole expansion rubber barrel is attached to the well wall, and the squeezing and injecting pipe column is fixed in a predetermined position. The control part achieves a unidirectional sealing function, guarantees that the liquid in the inner cavity cannot flow out due to change of the internal pressure of the cavity, and guarantees a stable sealing state in the expansion rubber barrel and the well during cement squeezing and injecting construction, thereby improving the success rate of squeezing and injecting cement in the barefoot well.

Description

technical field [0001] The invention relates to the technology in the field of oil and gas exploration and drilling, in particular to a cement retention pipe string and a cement extrusion tool. Background technique [0002] During the exploration of oil and gas wells, the cement in oil and gas wells is affected by various factors such as oil and gas migration, various stresses in the formation, corrosion, and unreasonable well structure, which makes the cement in oil and gas wells damaged. , resulting in oil layer collusion, formation cement destruction, formation of cavities near the wellbore, or failure of normal production of the oil well due to casing leakage. At this time, workover operations are required. In the workover operation, it is necessary to repair the damaged part through cement injection construction, so as to restore the production of oil and gas wells. [0003] Generally speaking, oil and gas wells are divided into cased wells and open hole wells accordin...

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Problems solved by technology

[0004] However, in the cement extrusion construction of the open hole, because the open hole wall is rocky, the well wall is uneven and irregular, the cement retainer of the slip anchor structure cannot be anchored on the well wall, and the sealing effect is poor. As a result, the success rate of squeeze cementing construction in open-hole wells is low, and the plugging effect is poor

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