SU1448027A1 - Arrangement for isolating troublesome zones - Google Patents

Abstract

The invention relates to the mining and oil and gas industries and. designed for drilling wells. The goal is to increase the efficiency of the TbJ device when cementing with traffic jams by controlling the trajectory of the drilling area of the isolated area. The device contains a flat housing (K) 1 connected to the detachable unit 9 in the upper part. Throughout

Description

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In the length K 1, there are centering rings 2. In the upper part K 1 below node 9 there is a groove 5 for the gripping elements, and in the lower part K 1 there are side holes 6, Rings 2 are made of elastic material with holes 3 around the periphery. The lower end of the K 1 is muffled. The holes 3 are made with the possibility of blocking at the end of cementing with the plugs 11. The peripheral parts of the rings 2 are connected by rigid elements in the form of steel reinforcement or a cable. To increase the insulation efficiency of the absorption zone.

The invention relates to the mining industry, and more specifically to the oil and gas production, and can be used in the drilling of wells for isolating zones of complications.

The purpose of the invention is to increase the efficiency of the device during cementing with traffic jams by controlling the path of drilling the zone of the isolated area, as well as to increase the efficiency of isolation of the absorption zone.

Figure 1 shows the proposed device, a General view; 2 is the same with rigid elements and a rubberized sleeve; FIG. 3 is the same after isolating the zone of complication and drilling out the cement bridge; figure 4 is the same in the case of a misalignment of the body and the well.

The device (Fig. 1) contains a cylindrical polyurellus 1, on which along its entire length there are centering rings 2 with openings 3 along the periphery for the passage of cement mortar 4. In the upper part of the body there is a groove 5 for gripping elements. parts of the body are made with lateral holes 6 for the passage of cement mortar. The backflow valve 7 is designed to prevent the cement slurry from entering after being pumped into a cylindrical hollow body. The lower end of the housing 1 is plugged with an end cap 8. The cylindrical hollow body 1 in the upper device has a rubberized sleeve. The drill pipes are lowered into the well and cement solution is pumped in, and then the plug 11 is lowered and the solution is blown to the bottom. At the same time, the solution passes inside K 1, exits from aperture 6 and rises through apertures 3 to the annulus. The number of mortar is calculated so that its upper boundary is lower than the groove 5. Depending on the design of the rings 2, the thickness of the cement stone ring is selected. 3 hp f-ly, 4 ill.

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Its part, which is connected to the drill pipe 10, is associated with stop-off. 9, the groove 5 is made below the detachable

5 of node 9. After the cement mortar is pumped into the drill pipes, the plug 11 is lowered. The device is designed to connect elastic centrifugal rings 2 along the peripheral part with rigid elements 12 in the form of steel reinforcement or a cable.

. When using the device in the absorption zone between the centering rings, a rubberized sleeve 13 is installed, hermetically attached to the end surfaces of the centering rings (Fig. 2). In this case, the holes of the centering rings, the side holes of the housing and the rigid elements are located inside the sleeve.

When drilling out the cement stone, a bottom-hole assembly (Fig. 3) is used, including a core bit 14, mounted on an approved drill pipe 15. At a distance from the bit equal to the distance from the lower end of the cylindrical 1L case 1 to the groove 5, a locking sub 16, having inside the petals 17, spring-loaded spring 18. Centering rings 2 are made of elastic material. The side holes are made with the possibility of blocking them at the end of cementing with traffic jams.

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For isopicating the curved area of complications, it is necessary to ensure the misalignment of the wellbore and the cylindrical hollow body (Fig. 4). In this case, the centering rings are asymmetrical, i.e. the width of the rings relative to the axis of the device is not the same.

The device works as follows.

In the pre-expanded portion of the well on the drill pipe 10 down a cylindrical hollow body 1 with centering rings 2, dispersed along the length of the body, with an outer diameter equal to the diameter of the extended section. In an unexpanded well bore ring, the deformed ring and body 1 passes to the extended section. In the extended region, the centering rings are straightened and the centrifugal casing 1 relative to the axis of the well, i.e. depending on the asymmetry or symmetry of the rings. After descending, cement mortar 4 is pumped into the drill pipes, and after the injection is completed, the blast 11 is lowered and the cement slurry is driven to the bottom. At the same time, the cement slurry passes inside the housing 1, leaves the opening 6, and, penetrating through the openings 3 of the rings 2, rises in the annulus.

In the case of using a rubberized sleeve to isolate the absorption zones, the cement mortar, rising between the housing 1 and the rubberized sleeve 13, presses the latter against the walls of the well. As the cement slurry is displaced, the stopper 11 is lowered to the check valve 7, as a result of which the passage of the cement slurry through the openings 6 stops. At this point, there is an increase in pressure, which is recorded on the pressure gauge, after which the pushing stops. The amount of cement mortar is calculated so that its upper boundary is lower than the groove 5. After the cement mortar sets, the drill pipes are folded back clockwise, unscrewing the left-handed detachable unit 9, and the drill pipes are raised. After the cement mortar has hardened, the assembly is lowered into the well to drill out the cement mortar.

stone (fig.Z). When drilling, the housing 1 passes into the core bit 14. The flushing fluid passes through the channel between the inner surface of the pipe 15 and the outer surface of the housing 1 and takes out the remains of the cement stone. After the cement stone has been drilled, the casing 1 fixes-0 s in the sub 16 by means of spring-loaded petals 17, which go into the bore 5, and rises to the surface when lifting the drill pipes. In the isolated interval 5 there remains a strong ring, created by rigid elements, which serve as a skeleton. Depending on the design of the centering rings, the thickness of the cement stone ring is 0 for each particular case.

Example: The borehole diameter is 151 mm, the diameter of the expanded bore in the application interval of the device is 214 mm, the length of the isolation interval 5 is 100 m, the number of centering rings is 10 pieces, the rings are located 10 m, the diameter of the cylindrical hollow body is 60 mm. After lowering the cylindrical hollow body and pumping the cement slurry, the drill pipe is unscrewed from the body and the column is lifted to the surface. After waiting for the cement to harden, i.e. after 16 h, a layout for drilling out cement stone consisting of a core bit with a diameter of 151 mm, a hole diameter of 64 mm, an outside diameter of drill pipe 0 is equal to 127 mm, an inside diameter of 10 mm, and an outer diameter of a fixed sub 127 mm.

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Claims (1)

1. A device for isolating complication zones, including a polyurellus, associated with a disconnecting node in the upper part, characterized in that, in order to increase its efficiency in cementing with traffic jams by controlling the TpaeKTopitfi drilling of the isolated area, it is provided with centering rings located along the entire length, which is fitted with a groove in the upper part below the detachable unit under the gripping elements and with side openings FIG. 2 / Fi.Z