Cementing device for thin interlayer adjustment wells

Abstract

The invention relates to a cementing device for thin interlayer adjustment wells. The cementing device comprises a casing string positioned in a borehole; a lower part of the casing string is provided with a thin interlayer linear seal packer; the thin interlayer linear seal packer is corresponding to the borehole thin interlayer in position; a lower end of the thin interlayer linear seal packer is connected with an annulus pressure compensator through a sleeve; a lower end of the annulus pressure compensator is connected with a float collar through a sleeve; a lower end of the float collar is connected with a float shoe through a sleeve. the thin interlayer linear seal packer comprises an upper joint and a center pipe; and upper end of the upper joint is screwed with an upper sleeve; an upper end of the center pipe is screwed on a lower end of the upper joint; the center pipe is sleeved by a rubber sleeve in the middle part; an upper end of the rubber sleeve is embedded in a rubber sleeve support which is installed on the center pipe in a sleeved mode; an elastic support mechanism is installed between an upper part of the rubber sleeve and the upper joint; two rubber sleeve clamp grooves are installed on a periphery of the middle part of the rubber sleeve and setting collars are embedded in the clamp grooves; a lower end surface of the rubber sleeve is provided with a hydraulic compression mechanism. By means of the device, thin interlayer can be reliably sealed and gas and water channeling is avoided.

Description

technical field [0001] The invention relates to a cementing device for oil drilling, in particular to a cementing device for adjustment wells with thin interlayers, and belongs to the technical field of oil drilling. Background technique [0002] With the continuous deepening of oilfield exploration and development, there are more and more adjustment wells in old areas with active oil and gas and complex formation pressure in thin oil layers, and the performance requirements for downhole tools for oilfield drilling and completion are also getting higher and higher. Especially in the late stage of high water-cut development, due to the influence of unbalanced injection and production, multiple pressure layers coexist in the vertical direction, seepage flow rate increases, interlayer contradictions are prominent, oil layers are many and thin, and the sealing section is long, so it is difficult for cement slurry to meet various requirements. Formation pressure requirements are ...

AI Technical Summary

Problems solved by technology

Packing layers below 3m are usually called thin barriers. For special wells with thin barriers, conventional packers cannot be used to meet the isolation requirements of oil well production. Longer conventional packers cannot be placed in thin barriers. If it is placed forcibly, it will seal off the oil and gas layer, which will affect the production of perforation and oil recovery in the later stage; or lead to a high channeling rate

In addition, the length of the packer is too long, it is inconvenient to transport, and it is not easy to run in the deflected well section with large dog legs, which limits its use to a certain extent

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