SU819309A1 - Device for washing-out borehole walls - Google Patents

Description

(54) DEVICE FOR WASHING WALLS WALLS

Possible to eliminate sticking of the pipe string.

This goal is achieved by the fact that the device is equipped with a clip, which is connected to the lower end of the flexible hose, with which it is located, the inner section of the sleeve is equal to or exceeds the tip of the head, and that the flexible hose is spring-loaded relative to the housing, and the device is spring-loaded an additional hose with a clip and magnetized directions, mounted on the body above and below the clip, to interact with the stuck pipe.

FIG. 1 shows a device for scouring the walls of a well; in fig. 2 shows section A-A in FIG. one; in fig. 3 .- layout diagram of the device; in fig. 4 shows a section BB in FIG. 3

The device consists of a housing 1, two shaped channels 2, flexible hoses 3, an end cap 4, nozzles 5, holders 6, a return spring 7, lower 8 and upper 9 magnetized directions and load-answer 10.

Two channels 2 are drilled in the housing 1, each of which has two sections: a vertical one of large diameter and one inclined of a smaller diameter. The axis of the inclined section has a smooth rounding in the zenith and azimuthal directions. Flexible hoses 3, which end at the bottom of the cage 6 with the jetting nozzles 5, the cavity of which is pain, are freely inserted into these channels. 4 sections of the end cap 4 flexible hoses. The end cap 4 seals the vertical section of the channel 2 and rests on the return spring 7. The downward movement of the flexible hose is limited by the end cap 4, and upward by the clip 6. The load 10, consisting of a UBT kit, is installed below.

When assembled, the system is a cylinder of equal section from load 10 to the end of case 1. Only case 6 and magnetized guides 8 and 9 project the dimensions of the case. The device is connected to the drill pipe either by small-diameter pipes or by means of a hinged diverter. by translators. To fill the pipe string with a liquid, a Descent valve of any design is installed at a distance of 100-150 m from the device.

The process of washing out the grooves and the mudcake is most difficult when eliminating the sticking of the pipe string, which has arisen due to the tool being pushed into the drain or because the column is pressed against the thick mudcake with differential pressure. Therefore, we will show the operation of the device in the most severe case using an example when there is a pipe string in the well and when a preliminary attempt to release the tool with a powerful pulse-wave load was unsuccessful.

Before the device is lowered into the well, the string of pipes disintegrates above the sticking boundary and the free part of the pipes is removed to the surface. Then into the well on pipes of smaller diameter (the column can be -component, consisting of a certain number of small-diameter pipes that are lowered into the well on drill pipes of the usual diameter) a device with a load of 10 suspended below is lowered

UBT.

Since this type of sticking occurs necessarily on the curvature of the wellbore section, the stuck part of the pipe string is unilaterally tightly pressed against the wall of the well, leaving the section of the well almost free. Therefore, the device passes into the well section with a stuck tool without restrictions, and since the barrel has a bend and the load 10 performs the role of a plumb, it enters the mobile

contact with a column of stuck pipes. The device is descended approximately, therefore, following the load, the magnetized directional devices 8 and 9 and the body 1 itself come into contact with the pipe body (see

5 of FIG. 2)

As soon as the device came into contact with the body of a stuck pipe string (which can also be recognized by measuring the length of the descent tool, using electrical or other known methods), high pressure injection pumps, such as pumps of a cementing unit or a drilling rig pump, are activated and pressure builds up in the cavity of the device . The pressure of the liquid, implemented on the cross section of the cavity of the cage 6, the flexible pipes 3 are put forward

5 through the bent channel 2 into the well, and from the nozzles of the nozzle 5, a jetting outflow of jet to the wall of the well begins. It is experimentally known that the outflow of a jet at a speed of over 80-120 m / s is capable of intensively eroding such a rock in which gutter workings can be formed. (The loose part of the mudcake is eroded by a stream with much less energy).

The extended flexible nozzles 3 are self-locking 5 relative to the walls of the well, because the distance from the wall of the well to the cut of the nozzle 5 is regulated by pressure in the outflow of the jet. In addition, in order to achieve self-installation of the nozzles relative to the surface being eroded, a flow with a large amplitude of pressure oscillations is pumped into the device (i.e., used with hydraulic compensators off). Due to this, a constant equilibrium of hydraulic and

5 mechanical (action of the return spring) forcing the flexible hose, constantly moving, to be kept at a certain distance from the eroded surface. Moreover, this distance will always ensure the maximum effect of the jet on the eroded surface.

At the same time, the device is self-installed with respect to the choke development, since all the surface irregularities will be controlled by the jets.

The downward speed of the device is determined by the erosion effect. During the washout process, reciprocating movements of the device are also possible.

After substantial destruction of the groove workings and the mudcake, the device is removed to the day surface, and any type of sowing pipe is lowered into the well, connected to the remaining casing pipe in the borehole and limited smashing is performed with beating ss if necessary.

If it is necessary to create radial channels in the formation around the well, the device descends on a rigid arrangement of the drilling tool. When assembling the device, the length of flexible hoses is selected in accordance with the planned depth of the radial channels.

Thus, the device allows to erode the gutters and cavities in the presence and absence of a pipe string in the well and to form radial channels in the reservoir around the well in an automatic mode to a predetermined depth. .

Claims (3)

1. A device for scouring the borehole walls, comprising a housing with channels, a flexible hose with a tip and a nozzle, mounted in the housing with the possibility of reciprocating movement, characterized in that, in order to increase the reliability of its operation, it is equipped with a lower end of the flexible the slash cage in which the nozzles are placed, the inner cross section of the cage being equal to or greater than the cross section of the end piece. 2. The device according to claim 1, characterized in that the flexible hose is spring-loaded relative to the housing. 3. The device according to paragraphs. 1 and 2, characterized in that, in order to make it possible to eliminate the sticking of the pipe string, it is provided with a spring-loaded additional hose with a yoke and magnetized guides mounted on the housing above and below the yoke. For contact with stuck pipe. Sources of information taken into account in the examination 1. USSR author's certificate No. 505786, cl. Е 21 В 7/18, 03.11.72. 2. USSR author's certificate No. 581229, cl. Е 21 В 7/18, 05.05.74 (prototype).