Packing type graded cement injection device

Abstract

The invention provides a packing type graded cement injection device. The packing type graded cement injection device comprises a secondary cement injection assembly, a rubber sleeve liquid injection assembly and a rubber sleeve packing assembly which are connected in sequence, the rubber sleeve liquid injection assembly comprises an inner liquid injection channel for providing initial expansion sealing pressure for the rubber sleeve packing assembly before secondary well cementation, an outer liquid injection channel for further providing expansion sealing pressure for the rubber sleeve packing assembly during secondary well cementation, and an opening component for opening the outer liquid injection channel when an external annulus reaches a certain pressure, the two ends of the outer liquid injection channel communicate with the inner liquid injection channel and the outer annulus correspondingly, and the opening component is arranged in the outer liquid injection channel. The packing type graded cement injection device has the advantages that the loading capacity of a packer is improved, the well cementation quality and the construction reliability are guaranteed, and the structure is compact.

Description

technical field [0001] The invention relates to the technical field of oil well cementing, in particular to an isolation type staged cementing device. Background technique [0002] With the wide application of packers in well completion and acid fracturing operations, their application in cementing operations is also increasing. The inner bag of the rubber sleeve of the packer used for well completion and acid fracturing increases with the increase of the pressure inside the pipe, and the pressure bearing capacity of the annulus outside the pipe is large; After the inner bladder of the cylinder reaches a certain pressure, the injection channel will be closed, which makes the pressure of the inner bladder of the rubber sleeve of the packer lower, and the pressure bearing capacity of the outer sealing annulus is low. [0003] With the continuous deepening of oil and gas exploration and development, the number of deep wells, ultra-deep wells, and lost wells is increasing, and ...

AI Technical Summary

Problems solved by technology

The inner bag of the rubber sleeve of the packer used for well completion and acid fracturing increases with the increase of the pressure inside the pipe, and the pressure bearing capacity of the annulus outside the pipe is large; After the inner bag of the cylinder reaches a certain pressure, the liquid injection channel will be closed, which makes the pressure of the inner bag of the rubber cartridge of the packer small, and the pressure bearing capacity of the outer sealing annulus is low

[0003] With the continuous deepening of oil and gas exploration and development, the number of deep wells, ultra-deep wells, and lost wells is increasing, and the requirements for the pressure-bearing capacity of the annulus of the packer are getting higher and higher, and the existing low-pressure packers cannot meet the demand. , it is very easy to cause the extrusion deformation of the rubber sleeve and the phenomenon of breakdown and rupture of the rubber sleeve, which is prone to problems such as leakage and oil, gas and water channeling during the cementing operation; at the same time, the low pressure bearing capacity of the packer makes the graded cementing The height of the cement surface cannot be controlled, thus affecting the cementing quality

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