SU1790662A3 - Method for cleaning bottom hole zone from mechanical impurities - Google Patents

Description

The invention relates to the field of operation of oil and gas wells, in particular, relates to methods for cleaning the bottom-hole zone of a well from a solid phase as a result of operation or drilling, and can be used to remove solid sediment (sand) from tanks with a vertical rise in fluid.

There is a method of cleaning the bottom-hole zone of the well with the baits, consisting in the descent into the well on the rope of a heavy hollow cylinder with a valve in the lower part and ascent when filling it with sand. The disadvantages of this method are low (57) Summary of the invention: the pipe string is equipped with check valves and a perforated feather in the lower part along the length, the pipe string is lowered by introducing the perforated pen into the surface of the mechanical impurities by a value that preserves the total area of the perforation holes of the pen above the surface 'indistinct solids of equal and greater lumen area of the pipe string. The washing liquid with washed out mechanical impurities is lifted along the pipe string by longitudinal vibration of the pipe string, and the dynamic level in the annulus is maintained above the level of the lower valve arrangement with the condition pgh <P _P l. where is the density of the washing liquid, g is the acceleration of gravity, h is the height of the column of washing liquid above the surface of uncleaned mechanical deposits; Rpl reservoir pressure. 1 ill.

performance, the possibility of breaking the tartar rope and wiping the production casing.

There are also known methods of washing a well with jet devices, as well as removing sand plugs with compressed air, aerated liquid and foams. The main disadvantage of these methods is the need to use a large number of oilfield equipment and the resulting high cost of work.

Closest to the claimed method of flushing wells (prototype) is

1790662 AZ flushing method, which consists in pumping flushing fluid into the well and removing it (with mechanical impurities) through elevator pipes to the surface.

The disadvantage of this method when it is used for washing sand plugs in wells with abnormally low formation pressure (ANPD) is that it is ineffective, since as a result of high pressure the flow of washing fluid injected into the well along with it into the formation of sand in the sand.

The aim of the invention ^ is to prevent crushing of solids / in the reservoir with abnormally low reservoir pressure (ANPD).

This goal is achieved by the fact that in the 'known method of washing the bottom-hole zone of wells from mechanical impurities, including the supply of flushing fluid to the annulus of the well, raising the flushing fluid along with washed out mechanical impurities along the pipe string and moving the pipe string as mechanical impurities are removed, according to the invention, pipe string length equipped with check valves and. with a perforated feather in the lower part, the pipe string is lowered by introducing the perforated pen into the surface of mechanical impurities by an amount that ensures that the total area of the perforation holes of the pen above the surface of uncleaned mechanical impurities is equal to or greater than the clearance area of the pipe string, and the washing liquid is lifted with washed out mechanical impurities along the pipe the column is carried out by longitudinal vibration of the pipe column, and I maintain the dynamic level in the annulus t is higher than the level of the bottom valve location under the condition pgh <Ppl, where p is the density of the flushing fluid;

g is the acceleration of gravity;

h is the column height of the washing liquid above the surface of uncleaned mechanical deposits;

P _PL - reservoir pressure.

The drawing explains the proposed method.

Implementation of the proposed method of flushing wells with an API is as follows. The tubing string 1 with check valves 2 is lowered into the well. To protect the production string 3 from mechanical damage, the string 1 is equipped with centralizers 4. The lower (receiving) end 5 of the string 1 is equipped with a feather 6 and is perforated at a length of 5-6 m. Column 1 is lowered to a depth , in which the perforated part 5 of the receiving pipe is immersed in the sand cork 7 so that above its surface openings A with a total flow area equal to or greater than the clearance area of the lift pipes remain free. The supply of washing liquid is carried out through channel 8.

When creating mechanical vibrations in column 1, loosening of the sand plug 7 occurs, and the liquid with mechanical impurities rises to the surface. As the sand plug is removed, column 1 is expanded.

Claims (1)

Claim The method of cleaning the bottom hole of the well from mechanical impurities, including the descent of the pipe string, the supply of washing fluid to the annulus of the well, lifting the washing fluid along with washed out mechanical impurities along the pipe string and moving the pipe string as the mechanical solids are removed, characterized in that, for the purpose elimination of crushing of mechanical impurities into the reservoir with an abnormally low reservoir pressure, the pipe string along the length is equipped with check valves and perforated In the lower part, the descent of the pipe string is carried out with the introduction of a perforated pen into the surface of mechanical impurities by an amount that ensures that the total area of the perforation holes of the pen above the surface of uncleaned mechanical impurities is equal to or greater than the clearance area of the pipe string, lifting, washing liquid with washed out mechanical impurities the pipe string is carried out by longitudinal vibration of the pipe string, and the dynamic level in the annulus is maintained above the level of distribution the position of the lower valve under the condition pgh <Ppl, where p is the density of the flushing fluid, g / m, g is the acceleration of gravity, m / s ² ; h is the column height of the washing liquid above the surface of uncleaned mechanical deposits, m; Rpl - reservoir pressure, Pa. ✓