SU1596076A1 - Device for cementing casing string - Google Patents

Abstract

The invention relates to the oil and gas industry. The goal is to increase reliability. The device includes a hollow body (K) 1. On the outer surface of the K 1 fixed top 2 and bottom 3 thrust ring. Between the upper 2 and lower 3 thrust rings are placed uniformly and in pairs permanent magnets 4, made in the form of cylinders and installed with the possibility of rotation around its axis and with a gap relative to K 1. Between the pairs of magnets in K 1 there are holes 5. The width of the gap between K 1 and the magnets 4 are not less than half the distance between the magnets 4, and the ends of the adjacent magnets 4 have opposite poles. The device is lowered into the well on the string of casing and placed above the productive horizon. A ferromagnetic powder is introduced into the buffer liquid. Before cementing, buffer fluid with a ferromagnetic powder is pumped into the annular space of the well. When pumping the buffer fluid through the device, the magnets 4 are drawn into rotation, and a ferromagnetic powder is attracted to them, which gradually condenses. When a certain thickness is reached, the rotation is stopped, and the space between the magnets is blocked by the ferromagnetic powder. Making the magnets 4 in the form of cylinders, and K 1 with holes 5 allows for the reverse cementing of the casing with a controlled signal for its termination and forcing the drilling fluid into the internal cavity of the casing. 3 il.

Description

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Holes 5 are made between the pairs of magnets in K 1. The gap between the K 1 and magnets 4 is not less than half the distance between the magnets 4, and the ends of the adjacent magnets 4 have opposite poles. The device is lowered into the well on the casing string and is placed above the productive grizone. A ferromagnetic powder is introduced into the buffer liquid. Before cementing, buffer fluid with a ferromagnetic powder is pumped into the annulus of the well. When pumping the buffer fluid through the device, the magnets 4 are drawn into rotation, and the ferromagnetic powder is attracted to them, which gradually condenses. When a certain thickness is reached, the rotation is stopped, and the space between the magnets is blocked by the ferromagnetic powder. Making the magnets 4 in the form of cylinders, and K 1 with holes 5 allows for the reverse cementing of the casing with a controlled signal for its termination and forcing the drilling fluid into the internal cavity of the casing. 3 il.

The invention relates to the mining industry, and more specifically to the oil and gas industry, and can be used in controlled cementing of casing strings in the reverse way.

The purpose of the invention is to increase reliability.

FIG. Figure 1 shows the layout of the device on the casing; FIG. 2 shows the node I in FIG. one; on fig.Z - section aa in figure 2.

The device for cementing the casing includes a hollow cylindrical body 1.C fixed to its outer surface by upper 2 and lower 3 retaining rings and permanent magnets 4 made in the form of cylinders. The permanent magnets 4 are installed evenly and in pairs between the upper 2 and lower 3 retaining rings rotatably around its axis and with a gap in relation to the housing 1, the housing 1 is made with holes 5 between the pairs of magnets 4, and the width of the gap between the magnets and the housing is not less half the distance between the magnets, and the ends of the adjacent magnets have opposite poles.

The total area of the holes 5 is not less than the area of the internal cross section of the housing 1 and the casing 6, and the total area of the gaps between the magnets 4 is not less than the total area of the holes 5.

The device works as follows.

The device is lowered into the well on the string of casing 6 and placed between the latter and the filter column 7. The device itself is installed above the production horizon 8. A well in the interval of the production horizon prior to cementing is filled with a temporarily blocking suspension 9 (for example, ground). After that into the annular

the space from the wellhead is sequentially pumped buffer fluid 10 and cement mortar 11, and the displaced drilling fluid from the annulus through the holes 5 enters the casing 6 and then to the wellhead. A ferromagnetic powder is introduced into the buffer fluid prior to injection. The drilling fluid displaced from the well is distributed

evenly between the pairs of magnets 4. The flow mechanism changes when the buffer fluid 10 begins to flow through the device.

At the moment when between pairs of magnets

4 will begin to pass the buffer liquid 10 with a ferromagnetic powder; in each pair of magnets, counter-rotating rotational motion will begin due to the magneto-force interaction of the ferromagnetic flux

fluids with magnetic cylinders, each of which rotates around its own axis. The rotational movement of the magnetic cylinders will be accompanied by a partial separation of the ferromagnetic powder by the surface of the cylinders 4 and they will be covered with a ferromagnetic powder over several turns, which will thicken as its thickness increases.

However, the moment will come when the hydrodynamic forces will come to equilibrium with the force of compression of the ferromagnetic powder, the magnetic cylinders 4 will stop, and the gaps between the magnetic cylinders 4 will be covered by the ferromagnetic material. That will signal the end of cementing.

Claims (1)

The invention The device for cementing the casing, comprising a hollow cylindrical body with permanent magnets fixed on its outer surface, characterized in that increase reliability, it is equipped with upper and lower thrust rings fixed on the outer surface of the housing, permanent magnets are made in the form of cylinders installed evenly and in pairs between the upper and lower thrust rings rotatably around its axis and with a gap relative to the housing, and the housing is made with openings between pairs of magnets, the gap between the magnets and the housing is no less than half the distance between the magnets, and the ends of the adjacent magnets have opposite poles. A- A