SU48041A1 - Drilling well filter - Google Patents

Description

The existing filters for a drill well, which are one column of perforated pipes, the diameter of which is the same for the entire column, are usually arranged as follows: after the drilling is completed, perforated pipes having a smaller diameter than the bottom casing are lowered into the well, all the pipes are removed from the well, and the space between the external surface of the perforated pipes, made up in one whole column, and the walls of the well is covered with gravel.

As is known, the casing string is made up of pipes of different diameters, the dimensions of which increase along the height of the column, and the difference between the diameters of the upper and lower casing pipes often reaches a considerable size, which makes the whole column resemble a telescopic pipe. When filling with gravel or other suitable material, the space between the perforated tube and the walls of the well released from the casing is that large surface of the cone-shaped well, which was obtained by drilling, on the other hand a sufficient amount of gravel is required for backfilling.

In the inventor's opinion, it is advisable to use the entire well surface obtained from drilling, for which he proposes a filter device in which the perforated string column would gradually expand similarly and according to the casing arrangement that was taken before the latter were removed.

The drawing shows the proposed filter device. FIG. 1 depicts a portion of a filter column in the proposed embodiment; FIG. 2 is a resolution; h according to AB of FIG. one; FIG. 3 is a cut-out of the CD of FIG. one; FIG. 4 is a method of screwing a ring into a sleeve; FIG. 5 shows a device for connecting two perforated pipes in another embodiment.

The device proposed filter is as follows. The filter string is formed from a whole series of perforated tubes inserted one into another. Each hole pipe 1 ends at its lower end with a socket 3 connected to it by a sleeve 4, into which a ring 2 is pre-screwed,

the inner diameter of which is slightly smaller than the diameter of the perforated pipe 1 located below for it

When the coupling 4 connects the pipe to the socket 3, the ring 2 is clamped between the latter when these parts are screwed onto one another. The ring itself is screwed into the sleeve with the help of a bolt 6 with a nut, which is temporarily inserted for screwing inside the ring, as indicated in FIG. 4, when unscrewing the nut with a wrench, the bolt is firmly clamped in ko, th °, resting against its inner surface with a nut and a head, after which the ring is screwed into the sleeve by the bolt.

FIG. 5 shows a few. another device for combining perforated pipes; here the bell 5 is directly screwed onto the end of the perforated tube, being provided inside with a protrusion replacing the ring 2 described above.

The filter is assembled as follows. First, the well 1 is lowered into the wellbore pipe 1 (Fig. 1), the diameter of which is slightly smaller than the diameter of the lowest casing and the lower end of this perforated pipe is sealed with a plug to create the bottom bearing surface of this pipe. The lowering is done in such a way that the upper end of the lowering pipe is 1–2 m higher than the shoe of the last but one J-position after the lower casing. Then, the lower casing itself is extracted and the next hole pipe G is slightly lower than the diameter 1 already installed in the borehole before it, but slightly smaller than the penultimate bottom casing; when the pipe 1 is lowered into the well, such a socket 3 fixed to its ends climbs onto the upper end of the perforated pipe 1, the latter being fixed in ring 2, and thus the perforated pipes are combined, after which the preceding casing is removed.

All other perforated pipes, having respectively larger and larger diameters for the casing, depending on the installation of the perforated pipes, higher and higher in the well, are set one on top of the other, in the same order as above, and each of the casing pipes immediately after replacing it with a filter perforated pipe is removed from the well, resulting in a whole column filter from perforated pipes, in its form "in appearance resembling a sliding telescopic pipe with expansion upwards.

The downhole of the well before the descent of the first perforated filter tube is checked and, if the bottom of the bottom is weak, the gravel is poured there beforehand in order to "create a solid base for the filter."

In those conditions, the la filter is placed in the flow pipe below the coupling, an oil seal can be placed which presses the guide socket 3 or the support ring 2 and closes the access to the flow filter through the place where the perforated pipes overlap each other.

The filter tubes are lowered into the well on the drill rods, to the lower end of which the well-known “descent” is mounted (see, for example, V. A. Zrelov, “Drilling wells, 1935 edition, ONTI, p. 21).

The subject invention.

Claims (2)

1. A filter for a borehole, which is a perforated pipe inserted into a borehole, characterized in that the perforated pipe is composed of a series of pipe sections, freely mounted one on top of the other and each having a diameter corresponding to the diameter of the casing. 2. The form of the filter according to claim 1, characterized in that the lower end of each tubular segment is provided with a bell 3, which by means of a coupling clamps ring 2, which serves as a support for this tubular segment.