SU1186781A1 - Arrangement for providing reverse local flushing of well - Google Patents

Abstract

A DEVICE FOR CREATING A REVERSE LOCAL WASHING OF A WELL, containing a cylindrical body with a discharge channel and an ejector, having a cylindrical shaped suction chamber located in the center and an eccentrically located nozzle and displacement chamber with a diffuser, different from the fact that, in order to increase the flushing efficiency, the outlets from the nozzles and the suction chambers into the displacement chamber are made in the form of slit-like channels oriented in the direction opposite to the direction of possible tangential rotation, respectively to the cylindrical lateral surfaces of the housing and the suction chamber, the displacement chamber has a recess shaped cross section which expands, in a direction opposite the direction of rotation can vozsl.

Description

The invention relates to mining, to means for removing cuttings from a well bore. The purpose of the invention is to increase the washing efficiency. FIG. 1 shows the proposed device, a longitudinal section; in fig. 2 shows section A-A in FIG. 1 in FIG. 3 shows a section BB in FIG. one; in fig. 4 is a view of B in FIG. 3. A device for creating backward local flushing of a well includes a housing 1, a pressure channel 2, a nozzle 3, a radial hole 4 communicating with the pressure channel, and having an outlet-slit channel 5 extending to the lateral cylindrical surface 6 of the body and oriented in the direction opposite to direction of possible rotation (to the left tangential to the cylindrical surface of the housing. The suction chamber 7 is located in the center and has a pin through the slot-like channel 8, which is adjacent to the nozzle 3 and is oriented in relation to to its lateral cylindrical surface 9. The recess 10 has a rectangular expansion in the direction opposite to the direction of possible rotation, the cross section and together with the borehole wall forms a displacement chamber and a diffuser. The suction chamber 7 is isolated from the discharge channel using a ball valve 11. The proposed device works as follows: The device as part of the drill string is lowered into the well without a ball valve 11. This allows the bone to directly wash the bottom from the sludge, which often accumulates cs in the well and may be the reason for the increase in resistance to reverse flow. The supply of flushing fluid without a ball valve occurs in two directions — into the filling space through the nozzle 3 and into the inside of the core pipe through the suction chamber 7. Since the resistance in the nozzle is greater than in the core pipe, this guarantees a direct flushing of the well and preliminary cleaning of its bottom from the accumulated sludge. Upon reaching the wellbore, through the internal channel of the drill pipe, the ball valve 11 is ejected, which closes the chamber 7 from the injection channel 2 and the fluid is completely injected into the annulus through the nozzle 3, creating a high flow rate into the mixing chamber formed by the recess 10 and the walls of the well. Due to this, in the zone adjacent to the nozzle 3 of the channel 8, a low pressure is created and the liquid from the suction chamber rushes into the mixing chamber and is displaced by the forces of the internal friction of the liquid due to the speed difference between the suction and the injected fluid, and as a result, the ejected return flow of bottomhole washing. In the expanding part of the displacement chamber (diffuser), the flow rates of the injected and suction fluid are equalized and their kinetic energy is transferred to the potential energy of pressure. In this case, the total flow from the diffuser is divided into a downstream to create a backwash and an upward - for direct circulation. The centrifugal forces of the flow of the injected and ejected fluid, as well as the tangential pressure of the fluid in the channel 8 due to the difference in rotation of the device body and the suction fluid create the conditions for a more efficient backwash and consequently an increase in the mechanical speed of drilling and regular deepening of the well. At the end of the voyage, the flow of fluid is stopped and as a result of the formation of the difference in the volume weight of the flushing fluid inside the core pipe, a direct flow occurs in the annulus.

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Claims (1)

A DEVICE FOR CREATING A BACKWATER LOCAL WASHING OF A WELL, comprising a cylindrical body with a discharge channel and an ejector having a centrally located LAY Figure 1 is a suction measure of a cylindrical shape and an eccentrically located nozzle and a displacement chamber with a diffuser, characterized in that, in order to increase the washing efficiency, the exits from the nozzle and the suction chamber to the displacement chamber are made in the form of slit-like channels oriented in the direction opposite to possible rotation along the tangent, respectively, to the cylindrical lateral surfaces of the housing and the suction chamber, while the displacement chamber has the form of a recess, the cross section of which expands to the opposite, § w direction of possible rotation. SU „., 1186781 1 1186781