SU1548414A1 - Apparatus for interval-wise pumping of agents into hole bottom zone of well - Google Patents

Abstract

The invention relates to the oil industry. The goal is to increase the efficiency of interval injection of reagents into the wellbore zone by preventing the well fluid from entering the formation. For this, inside the housing 1 there is a sleeve 6, spring-loaded with respect to the housing 1 by a spring 7. Inside the sleeve 6, a saddle-nozzle 8 with a ball 10 is installed by means of shear pins 9. In the housing 1, a first additional row of holes is made above the upper sealing element 2. The latter in the transport position are covered with a sleeve. In the lower part of the housing 1, a saddle 14 is formed to interact with the saddle nozzle 8. To eliminate abrasive wear when leaching the reaction products from the wellbore zone and hydrodynamic effects on the bottomhole well when the device is raised to the surface, it has a nozzle 12 with a number of through-holes plugged out , and suspended in the housing 1 on the shear pins 13 above the sleeve 6. The housing 1 has a second additional row of holes that are blocked in the transport position by the nozzle. When pins 9 are cut, the saddle-nipple 8 falls into the saddle 14, and the row of radial holes in the housing is blocked by the sleeve 6. This device has an increased service life. 1 hp f-ly, 4 ill.

Description

The invention relates to the oil industry, namely, devices for processing the bottomhole zone or shutting off the watering parts of productive formations during the injection and operation of wells.

The aim of the invention is to increase the efficiency of the interval injection of reagents into the wellbore zone by preventing the well from entering the formation and eliminating abrasive wear when leaching the reaction products from the wellbore zone and hydrodynamic

impacts on the well bottom zone when the device is raised to the surface.

FIG. 1 shows the device, the transport position; FIG. 2 - the same, with the approach of the reagent on the tubing to the device and the supply of liquid from the tubing (water, saline solution, mud, etc.) into the annular space of the well, in Fig. 3 - the same, with interval injection of the reagent into the bottomhole zone the wells in FIG. 4 - the same, when leaching the reaction products from the bottomhole zone through the tubing above the device.

The device consists (Fig. 1) of the housing 1 with a number of radial holes A, the first additional row for the radial holes B and the second additional row of radial holes Br of the upper 2 and lower 3 sealing elements attached to the housing of the differential sleeve 4 a series of radial holes G9 spring-loaded

about

five

0 5 0

c

spring 5, sleeve b, spring 7 relative to the body, saddle-bushing 8 suspended on the inner surface of the bushing on shear pins 9 with ball 10 placed in it and fixed with rod 11 to hold the ball plugged from the bottom 12c the Snea lock is shown) having a series of through holes D in the wall and suspended in the housing on the shear pins 13S of the seat 14.

The device works as follows (Fig. 2 and 3).

After descending into the well on the tubing, the device is placed in the production string 15 so that the sealing elements 2 and 3 are located respectively above and below the perforation zone E in the interval of injecting reagent into the bottom hole zone of the well. When the reagent 16 is fed into the tubing, the sleeve b, together with the saddle-pipe 8, moves downward, revealing a number of radial holes B through which fluid from the tubing enters the annular space above the bottomhole zone of the well. At the approach of the reagent 16 to the device, the pressure in the tubing is increased to the calculated value at which the pins 9 are cut off and the saddle-pipe 8 falls down into the saddle 14. At the same time, in the case a row of radial holes B is blocked by a spring-loaded sleeve 6, sealing elements 2 and 3 differential sleeve 4 moves - BHH3S squeezing the spring 5 to align

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a number of radial holes G with a number of radial holes A in the housing. The reagent enters the device and through the combined rows of radial holes A and G it is pumped into the intercapping zone and then through the perforations E into the bottomhole zone 17 of the well.

After injection of reagent 16, for example, hydrochloric acid solution, to treat the wellbore zone in order to increase well productivity, the overpressure in the tubing is released, while the sealing elements 2 and 3 unpack the annulus, and the differential sleeve 4 returns to its original upper position (Fig. . four).

After scavenging the reaction products, the device is lowered below the bottom-hole zone after treatment with hydrochloric acid solution. In the tubing 18, a solid metal plug 19 is introduced, which, when struck against the plugged bottom 12, cuts off the pins 13, and the plug 12 together with the plug 19 moves down to the stop into the sleeve 6 and is connected to it with a lock. In this case, a number of radial holes B are opened in the housing, through which fluid is circulated from the annulus to the bottomhole zone of the well in the tubing above the device.

When the device is lifted from the well, a number of radial holes B circulates the fluid from the tubing into the annulus of the well.

An example. In the well, the productive stratum is represented by three oil-bearing strata, located one from another at a distance of 8–10 m. The 15-14 146-mm production column is perforated at intervals opposite each reservoir. FIG. 2 and 3 shows the bottomhole zone 17 of the middle oil-bearing formation with a capacity of 10 m, located at a depth of 2500-251 Ohms. In the case of acid treatment of the formation, it is necessary to inject into the wellbore zone 6 m3 a 12% aqueous solution of hydrochloric acid under a pressure of 25-28 MPa. The device is lowered into the well on tubing with a diameter of 73 mm, the volume of which is equal to 7.5 m3 “The well is filled with a saline solution with a density of 1.1 g / cm. The pins 9 of the device are designed for shearing with an overpressure in the tubing of 6.0 MPa,

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which is provided when the regent is supplied to the tubing by a cementing unit with a capacity of at least 8 l / s. Therefore, the reagent is supplied to the tubing with a capacity of 7 liters / s. After 18 minutes from the beginning of the supply of the reagent to the tubing, when the latter reaches the device, the productivity of the cementing unit is increased over 8 l / s. At the same time, the pins 9 are cut, the saddle-nipple 8 falls into the saddle 14, and the row of radial holes B in the body is blocked by a spring-loaded sleeve 6. As a result, sealing elements 2 and 3 are packed in the production string 15, and the reagent 16 is pumped into the bottomhole zone 17. The performance of the cementing unit during the injection of the reagent is adjusted so that the overpressure in the tubing does not exceed, for example, 30.0 MPa (allowable pressure drop across the sealing elements of the device).

Thus, the advantages of the proposed device for sequential injection of reagents into the wellbore zone are determined by:

prevention of contamination of the reservoir with liquid from the tubing during the interval injection of reagents into the well bottom zone, and as a result, increase of productivity of wells x

preventing the reagent from mixing in the wellbore zone of the well with the fluid filling the tubing before reagent injection, and, consequently, improving the quality of the insulation works when watering reservoirs are turned off

protection of the device from hydrodynamic effects and abrasive wear during leaching of the reaction products from the pre-abonic zone after its processing and subsequent lifting of the device from the well and, as a consequence, increasing the operating life of the device.

Claims (1)

1. A device for interval injection of reagents into the well bore zone, comprising a housing with a number of radial holes, above and below which there are upper and lower sealing elements, and a differential sleeve, spring-loaded relative to the body, with a number of radial holes, characterized in that, in order to increase the efficiency of the interval injection of reagents into the well zone of the well by preventing the well fluid from entering the formation, it is equipped with a sleeve located inside the body and spring-loaded relative to body, saddle-pipe with a ball mounted inside the sleeve by means of shear pins, and in the body above the top sealing element made the first additional series of miles, which is blocked in position transporno sleeve and the lower portion of the housing is satisfied, the saddle with an axial bore for engagement with a saddle tube. 2, The device according to clause 1, about tl and - preferably, in order to avoid abrasive wear when leaching the reaction products from the well bottom zone and hydrodynamic impacts on the well bottom zone when the device is raised to the surface plugged from below and installed in the housing by shear pins above the sleeve with a nozzle with a radial hole, the second additional row of holes being made above the first additional row of holes, which are in transport position covered pipe. W. Figure 2 W FT.1