SU1745896A1 - Well cementing device - Google Patents

Abstract

Use: for step cementing wells. Provides the possibility of improving the quality of cementing by increasing the tightness of the cementing plug and the uniformity of its wear. In addition, the hydraulic activation of the cement slurry is carried out simultaneously by vibration. The device includes a housing 1 with cementing openings 13. The cementing openings are blocked by the positioning sleeve 2 of the radial openings 4 and the mounting seat 5 in the lower part under the cementing plug 6. The cementing plug is made with radial holes 8 and an axial channel 10. In its axial channel placed vibration mechanism. This mechanism is made in the form of a piston 9. The piston is spring-loaded relative to the cementing plug and forms an annular cavity 11 above its radial holes. The annular cavity is hydraulically connected to the radial holes 4 of the position bushing. 11. When pushing a cement plug, the vibration mechanism does not work. The push pressure is transmitted to the inter-cartridge space of the cement plug. This ensures that the cement plug is centered. In the working position, the pressure drop over the piston causes it to reciprocate. This provides vibration treatment and activation of the cement slurry during pumping. 1 il. 1 (L with vj - SP 00 you o

Description

The invention relates to the drilling of oil and gas wells and can be used in the step cementing of wells.

A device for stepwise cementing is known, consisting of a hollow cylindrical body, a ring, a flap, upper and lower bushings, shear pins and an anvil ring. When cementing the upper stage, a slug tube is used, after landing on the stop ring, the injection of liquid into the well is stopped and put into the column, which opens the tube that sinks into the squeezing fluid, and upon reaching the lower sleeve saddle, the injection of liquid into the well is resumed. Under the action of the fluid injection pressure, the sleeve shifts down and opens the side opening. Next, the well is washed and after 03C of the first stage, cement solution for the lower stage is pumped into the column.

It is also known a well cementing device comprising a casing string connected to a cylindrical pipe provided with radial channels and a seating seat, a squeeze plug.

A device for cementing wells is known, which includes a housing with cementing openings, a stop ring placed in the axial channel of the housing, a mechanism for blocking cementing openings and a cementing plug with a vibro-action mechanism on the cement mortar.

A disadvantage of the known device is the low quality of cementing due to the insufficient tightness of the cementing plug and the unevenness of its wear, as well as the impossibility, simultaneously with vibration, to effect hydraulic activation of the cement mortar.

The purpose of the invention is to improve the quality of cementing by increasing the tightness of the cementing plug and the uniformity of its wear, as well as the possibility of simultaneously activating the hydraulic activation of the cement mortar.

This goal is achieved by the fact that in the device, which includes a housing with cementing holes, a stop ring placed in the axial channel of the housing, a mechanism to block cementing openings and a cement plug with a vibration mechanism on the cement mortar, the cementing openings of the housing are above the stop ring in the form

radial holes, the overlap mechanism of which is made in the form of a positional sleeve with radial holes, a lock of its intermediate position and a seating seat under the cementing plug, the latter being made with radial holes hydraulically connected with the radial holes of the position sleeve, and with an axial channel , but

The vibration mechanism is made in the form of a piston tube that is spring-loaded relative to the cementing plug and is placed in its axial channel and forming an annular cavity above it with its radial holes, which is hydraulically connected with the radial holes of the position sleeve, whose cross-sectional area is larger than the cross-sectional area of the ring cavity. The economic effect of using the invention is obtained by eliminating the cost of repeated insulation work in the event of poor cementing using known equipment.

The well cementing device consists of a housing 1 (FIG. 1), inside of which a position bushing 2 is installed and connected to it with shear pins 3. A position bushing 2 is provided

radial holes 4 and a stop ring 5. Inside the housing 1 there is also a cement plug 6, provided with an axial channel 7 and radial holes 8. The piston 9 of the vibration mechanism

the cement mortar is installed in channel 7 consisting of two stages. The upper stage 10 is located above the radial holes 8, has a diameter greater than the diameter of the piston 9 and forms between them an annular

cavity 11. The cross-sectional area of which is smaller than the cross-sectional area of the holes 8. The lower stage 12 is located under the radial holes 8 and is made according to the diameter of the piston 9. The housing 1 is equipped with radial holes 13, under which are placed the saddle 14 under the cementing plug 6, rigidly connected to the housing 1, and the latch 15 of the intermediate position of the sleeve 2, connected to the housing 1 by means of shear pins 16. The piston 9 is spring-loaded relative to the plug b by means of the spring 17.

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Claims (2)

1. A device for cementing wells, including a housing with cementing openings, a stop ring placed in the axial channel of the housing, a mechanism to block the cementing openings and a cementing plug with a vibro-action mechanism on the cement mortar, which is designed to improve the quality of cementing the expense of increasing the tightness of the cementing plug and the uniformity of its wear, as well as the possibility simultaneously with the vibration of the hydraulic activation of the cement mortar face to face openings formed on the housing a stop ring in the form of radial holes overlap mechanism which is designed as a bushing with radial positional apertured retainer its intermediate position and the valve seat under the wiper plug, the latter is provided with 0 five radial holes hydraulically connected with the radial holes of the position bushing, and with the axial channel, and the vibration mechanism is designed as a piston spring-loaded relative to the cementing plug, placed in its axial channel and forming an annular cavity above it with its radial holes associated with the radial holes of the position bushing, the cross-sectional area of which is larger than the cross-sectional area of the annular cavity. 2. A device according to claim 1, characterized in that the annular cavity is formed by making an annular groove in the axial channel of the cementing plug over its radial holes.