SU1263816A1 - Apparatus for reverse cementing of casings - Google Patents

Abstract

The invention is relative to smhiltsTI burSN1-TH II llO-MinriHCT ilOHhirilTb PP pdezhnost of work of the device GSPP ml of gchot automatic srlbltyi.ppg it iindezhny overlap colp) 111y; after the end of cementation pressure, the length of the J TO device has a bristle sleeve (5 with a conical outer surface in the BcpxHeii part, interposed between the radius. 1; e; samples

Description

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(PTi 3 and its seating saddle 4, and RP 3 is fixed in the hollow body 1 above the casing shoe 2 and has circulation holes (up to) 12. Body 1 has radial holes 7 against upper part B 5, Compressive force of spring B 5 is less forces of unlocking DF 3. When re-cementing, buffer fluid is pumped into the annulus of the well, the locking elements 13 are poured and the cement mortar is shut in. When the shoe 2 reaches the solution, the elements 13 clog the CO 12. The pressure from the overpressure in the annulus ve through the central heating station 12 is transmitted to RP 3. It is unlocked and moves up to the seat 4, RP 3 then performs the function of a check valve, reliably separating the annular space from the pillar. At the same time, the device creates the conditions for automatic activation of RP 3, 1, silt.

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The invention relates to the drilling of wells, in particular, to devices for cementing them in the reverse manner.

The purpose of the invention is to increase the reliability of the operation of the device by providing automatic operation and increasing the reliability of column overlap after the end of cementing,

The drawing shows the device in the transport 1st position, General view

The device includes a hollow body 1, a casing shoe 2, a separation plug 3 fixed in the housing 1 above the shoe 2, and a landing j: o 4 under the dispensing plug 3.

A spring-loaded sleeve 5 is placed between the separating plug 3 and its landing seat 4, which is made in the upper part with a conical outer surface 6. The body 1 against the conical surface 6 is made with radial holes 1 and 7.

The separator plug 3 is tucked under the pipe 8 and fixed, for example, by a spring ring 9.

In the upper part of the spring-loaded sleeve can be installed, for example, the disk 10.

Radial ot1-, Dersti 7 are made under zaporn; e elements, for example, from fluoroplastic, which are placed in the first portion of the cement slurry.

The spring 11 is made on the compression force less than the effort of uncoupling the separation plug 3. The body

under the separating plug 3 there are made with circulation holes 12. The device operates as follows.

When the casing is being lowered into the well, the internal cavity of the string will be filled through the radial holes 7 only if there is a differential pressure of the fluid in the annular and tubular space, corresponding to the compressive force of the spring 11, respectively. on the mouth

during the descent.

Intermediate flushing during the descent of the column, as well as flushing at the bottom, can be carried out either in the forward or in the reverse direction.

circulation

When reverse cementing is used, a portion of a highly viscous buffer fluid is pumped into the annulus before mixing the cement slurry, for example, a highly concentrated suspension of CMC in water. Then, at least 5060 locking elements 3 fall asleep under the radial holes 7 and proceed to

mixing cement mortar. Moreover, the mixing should be carried out at the highest possible performance in free-flow mode. The column is recommended during mixing.

Stroll slowly, turbulent the flow of cement slurry, for better substitution.

When reaching the first portion of the cement mortar shoe column,

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the flow shut-off elements block the circulation holes in the spring-loaded sleeve 5. All the force from the overpressure in the annulus is transmitted through the circulation holes 12 to the separator plug 3, which, expanding the spring ring 9, moves upwards, pulling the disk 10 to seat 4, From this moment on, the plug acts as a check valve, reliably separating the annular space from the column. In this case, the device creates the conditions for the automatic activation of the separation plug.

Claims (1)

Invention Formula A device for reverse cementing casing columns containing 638164 A hollow body, a casing shoe, a separating plug is fixed in the case above the shoe, and a landing seat for a separating plug, characterized in that, in order to increase the reliability of the device by ensuring automatic operation and increase reliability 10 of the column overlap after the end of cementing, it is equipped with a spring-loaded sleeve placed between the separation plug and its seat and made in the upper part 15 with a conical outer the surface against which the body is made with radial holes and a seat under the conical surface of the sleeve, while the force 20 compression of the spring of the sleeve is less than the efforts to unlock the separation plug.