The invention relates to the oil and gas industry, in particular to underground repair and renewal operations at oil wells.

There is a device [Gadiev S.M. Using vibration in oil production. Moscow; Nedra, 1977, p.117-120] for cleaning botom-hole area of a production well, comprising a casing with a sleeve to connect the tubing placed in the production well, at least one source of vibrations located in the casing.

The main disadvantage of this device is the absence of brashes for mechanical cleaning and the absence of impulse action.

The technical problem of the invention is the treatment of the casing surface with the mud-pulse forces of fluid and achieving an increase in the efficiency of cleaning the inline build-up.

The technical problem is solved due to the fact that the device is equipped with a valve actuating gear, which consists of a valve with a retaining washer with a cotter pin and a spring located inside, a hammer with notches for O-rings, and a tray fixed with a retaining ring; the device for generating mud-pulses is made in the form of a hydraulic impulse generator.

The technical result of the in vention is the improvement of the efficiency of cleaning the botom-hole area from scale build-up.

The invention is clarified with graphical appendices, where the bottom-hole cleaning device is presented in FIG. 1.

The de vice consists of an adapter 1 with brashes 2 and a casing 3. The adapter has a slot for tightening with an O-ring, staggered brushes of stainless steel (in the form of a line) on the outer surface of the 7 ^th level adapter, and is connected to the casing of the hydraulic impulse generator 3 with a retaining ring that is installed in the inner groove of the casing. Brushes can be bolted to the pipe surface. The cylindrical casing has 4 rows of 6 holes each for fluid outlet. Inside the casing of the hydraulic impulse generator, there are: a valve 4, a spring 5, a cylinder assembly 6, a hammer 7, and a tray 8. The valve consists of a thrust ring, a spring-loaded washer, a spring, and a coter pin that fixes the washer. The hammer, which has a hollow body below the valve, has three lip rings. The hammer has 4 grooves 10 mm thick at the bottom that pass fluid into the bottom row of holes, The tray 8 is installed into the casing from below and fixed with a retaining ring.

The treatment of the botom-hole area of oil wells is performed using the device in the sequence described below. First, the device is lowered and the surface is cleaned with brushes. Further, a chemical solution, a scale inhibitor selected according to the composition of formation water (hereinafter referred to as fluid) flows through the drill pipes into the adapter and then flows on the spring-loaded valve, which temporarily closes the flushing channel, where the fluid pressure pushes the valve down. The working fluid flows around the valve and enters the inner cavity of the hammer through the lower triangular groove of the valve . Under pressure, the fluid flow enters the lower row of side channels through the lower grooves of the hammer and leaves the hydraulic impulse generator, reducing the pressure inside the casing, Due to the low pressure inside the casing, the spring- loaded valve closes the adapter flushing channel, the pressure rises and the cycle repeats. This leads to the occurrence of oscillation, resonance phenomena, and water hammer.

Initial tests were carried out at the drilling site “South Karamurun”, where positive results were obtained. The device was installed on the well development unit “UOS” and introduced into production.

The obtained results are shown in Table No. 1.

In 16 problematic wells, in which an unstable rate of recovery was observed, a submersible hydraulic impulse generator was used. As a result, due to its use, the rate of recovery of the wells was increased approximately to 27 m3/h, in addition, the time for using special-purpose machinery was reduced approximately to 3 hours, and the time for flushing and completion was as little as up to 36 hours.

Further, the work on testing and implementation was continued at the drilling site “Tortkuduk”, the results were positive, they are shown in Table 2.

In 10 wells, where there was an unstable rate of recovery, with the help of a hydraulic impulse generator, the rate of recovery was increased with a maximum rate of 37 m3/h, the time for using special-purpose machinery was reduced to 3 hours, and the time for flushing and completion was as little as up to 16 hours.