SU1177447A1 - Metal-trapping device - Google Patents

Description

The invention relates to the drilling of wells, and in particular to devices for cleaning the bottom of a well from metal objects during drilling.

The purpose of the invention is to increase the efficiency of removal of small particles from the cumulative cavity and prevent compaction of the collected sludge.

FIG. 1 shows the device section; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a section BB in FIG. one.

The metal catcher consists of a housing 1 with ribs 2 stiffness, a casing 3 with bottom grates 4 (FIG. 3) fixed on the ribs 2 of rigidity, and a fairing 5 fixed on the housing 1 under the bottom of the casing 3.

Between the fairing 5 and the grate 4 there is a gap 6 of the required height. In the casing 3 there are vertical rows of inlet 7 and outlet 8 holes. The outer surface of the housing 1 and the inner surface of the casing 3 is formed cumulative cavity 9 in the form of annular sectors. The outer diameter of the fairing 5 is equal to the outer diameter of the casing 3.

The number of ribs 2 stiffness may be more than three. The number of vertical rows of holes is twice the number of ribs 2 stiffness. The length of the vertical row of holes is limited by the length of the stiffener, which is shorter than the casing 3, and the row of holes does not reach the upper edge of the casing 3. '

Moreover, the axis of the holes 7 and 8 are located on the same horizontal line in each annular sector and lie on the chord of this sector.

Case 1 at the ends has threads for fixing the metal trap in the drill string. The metal catcher is installed in the drill string directly above the chisel.

2

Metal catcher works as follows.

Metal objects, drill cuttings particles rise from the bottom

5 upward flow of washing fluid above the upper cut of the casing 3.

In this place, the speed of the ascending flow sharply decreases, since the cross-sectional area of the annular space increases, therefore metal objects and large particles of rock begin to fall from the ascending fluid flow and enter the cavity 9 due to both the gravitational force and the downward flow moving from the top cut of the casing 3 to the gap 6. In the gap 6 due to ejection - a zone of reduced pressure, therefore from the cavity 9 through the grate

² θ 4 and the gap 6, the fluid is sucked into the annulus. Metal objects and large particles of rock, falling on the grate 4, fall into the zone of holes 7 and 8. In this zone

25 due to the special orientation of the axes of the inlet 7 and outlet 8 holes (Fig. 2), which converge at an angle of 60 ° with three stiffening ribs 2, a fluid flows inside the cavity 9 in the direction opposite to the rotation of the metal trap. This flow removes fine particles, washing metal objects and large particles at the entrance to the accumulator cavity of the metal trap. In addition, the removal of fine particles from the cavity 9 is carried out and downward flow through the grate 4 and the gap 6.

40

In this case, the centrifugal forces contribute to the effective removal of metal and rock particles that have passed through the grate and have fallen into the gap 6.

45 Screening of fine metal particles and

breeds through the grate contribute

1177447 4

also vibrations of the bottom of the drill string.

Even when the circulation of flushing fluid is turned off during the buildup of the drill string due to 5

tool motions up - down small particles of rock washed out of the accumulative cavity, equipped with a bottom, made in the form of radial blob. ten

The presence of radial grate with vibration of the bottom of the drill string contributes to the crushing of large particles of rock with metal objects in the cumulative cavity and the removal of crushing products from it, which also increases the useful (for metal) capacity of the cavity.

Thus, the separation of metal objects and large rock particles from small particles in the proposed metal trap occurs during the entire process of deepening the well, and not only during the circulation of the washing liquid. In addition, the hydraulic connection of the accumulator cavity of the metal trap with the annular space both above and below, through the gap 6, eliminates the sealing of its contents under the influence of the hydrostatic pressure of the liquid column in the well. This will facilitate the removal of metal scrap and large particles of rock from the accumulative cavity after lifting the metal trap to the surface.

Aa

Bb

Fig, 7.

Fig.Z

Claims (2)

1. METAL, containing the body with ribs, equipped with connecting threads, and a casing with holes, forming a casing cavity in the form of ring sectors with the case and stiffeners, characterized in that, in order to increase the efficiency of removing small particles from the cumulative cavity and prevent compaction of the collected sludge, the metal trap is equipped with a ring fairing installed on the case and forming a gap with the bottom of the casing, the latter being in the form of radial grates. with <O 5 C 1177447 1 1177447 2. The metal catcher according to claim 1, about t - dami, with the axis of the holes characterized by the fact that the neighboring rows are located on in the casing are placed in each ring of the same horizontal along the chord of the ring the target sector has two vertical longitudinal sectors. one