RU2039221C1 - Apparatus to facilitate productivity of stratum by implosion method - Google Patents

Abstract

FIELD: oil extracting industry. SUBSTANCE: hollow body has in its lower part a hole, covered with destructible lid. Body has at least one mounted in it damper with hole, diameter of which is less than diameter of the body. Damper divides body for cavities with capability for them to communicate to each other. Diameters of dampers holes are decreasing from bottom one upward. EFFECT: apparatus and method are used in oil extracting industry. 2 cl, 4 dwg

Description

 The invention relates to an increase in oil recovery in wells, but can be used in other areas where the effect of implosion is required (explosion inside).

 Known devices used to increase oil recovery or injectivity. A high-explosive torpedo is a thin-walled case filled with explosive, a fuse that connects through a cable head to a wireline cable and then to a current source at the wellhead [1] The disadvantage of this device is that the torpedo after the explosion completely fails. To equip torpedoes need special charging workshops. Explosive stock required. Increased risk of work.

 A device is known for processing the bottom-hole zone by implosion methods. The device contains a hollow metal body with bleeding holes that increase water hammer, a replaceable fitting, a glass plug that is destroyed by an electric detonator [2] The disadvantage of this device is that the implosion effect is accompanied by a hydraulic shock, which destroys and seals the bottom-hole zone, reduces its permeability. This negatively affects the increase in oil recovery or injectivity of the reservoir, i.e. its productivity decreases. Water hammer also leads to the destruction of the device, which reduces its reliability.

 The aim of the invention is to eliminate the above disadvantages.

 This is achieved by the fact that the device comprises a hollow body with an opening in the lower part closed by a destructible lid, and an electric detonator, the hollow body is equipped with at least one damper with an opening installed above the electric detonator and dividing its cavity into separate chambers with the possibility of their communication, the diameter the holes in the damper are smaller than the diameter of the holes in the housing. If there are several dampers, then their diameter decreases from lower to upper.

 Figure 1 presents the proposed device; figure 2 the moment of its operation; figure 3 shows a graph of pulses of depression and compression, Rg hydrostatic pressure at a depth of immersion of the device; τ is time; figure 4 is a positive pressure pulse.

 The device consists of a cable head 1, a hollow body 2 with a hole in the lower part, which can be made, for example, in an adapter 3, closed by a convex destructible cover 4 through a gasket 5 and sealed by a bandage 6. An electric detonator 7 with a conductive core is placed on the destructible cover 4 8. In the housing 2 above the electric detonator 7 is installed at least one damper with a hole 9, which divides the cavity of the housing 2 into separate chambers. The diameter of the hole in the damper 9 is less than the diameter of the hole in the housing 2 (adapter 3). Figure 1 also shows the casing 10.

 The device operates as follows.

 The device is assembled (as shown in figure 1) is lowered into the well, for example oil, on a wireline (not shown) in the interval of the productive horizon. Next, through the cable and current-carrying core 8, an electric pulse is supplied to the electric detonator 7. The explosion of the electric detonator 7 leads to the destruction of the cover 4. A well fluid, such as oil, rushes into the hollow body 2, where the pressure is atmospheric.

 The reservoir through the perforations of the casing string 10 (not shown) is subjected to a sharp discharge from the hydrostatic column of fluid in the well. The reservoir pressure, which has become significantly greater than the borehole pressure, releases the fluid, colmatant, residues of the drilling fluid from the reservoir into the zone of reduced pressure, into the cavity of the housing 1 (figure 2). The formation is being cleaned. The pressure unloading in the form of a pulse propagates spherically from the inlet of the adapter 3. Then the liquid column, settling, begins to create a compression pulse. As soon as the liquid reaches the damper with the hole 9, it begins to throttle to the upper part of the housing 1, which creates its braking (damping), which removes the water hammer that would occur if the entire cavity of the device were filled with surrounding liquid without a damper. Due to the fact that the braking of the fluid can be multistage, i.e. put a damper in the liquid path through a certain gap, the hole of which is smaller than the hole of the previous damper, the fluid flow rate can be slowed down smoothly, eliminating the water hammer completely.

 It is known that the greatest effect when cleaning the reservoir gives a sharp decrease in well pressure (depression). In this case, sludge and fluid are ejected from the formation into the well, new productive cracks in the formation are revealed, the formation is cleaned, and its productivity sharply increases. The sludge settles in the sump of the well.

 A positive pressure impulse (water hammer), like a high-explosive torpedo explosion, gives a destruction zone, a zone of plastic deformation and a zone of elastic deformation. The fracture zone may include casing, cement ring and reservoir. To the zone of plastic deformations, a layer that is compacted reduces its permeability, squeezes oil from the well, which ultimately reduces the effect of implosion.

 Thus, two mutually exclusive parameters of depression (implosion) and compression (water shock) reduce the overall positive effect.

 In the proposed device, the second parameter is significantly smoothed, which increases the overall effect of cleaning the reservoir and reduces the dynamic load on the device, and this increases its reliability. Due to the fact that the device is simply designed (the cable head is connected to the housing through the standard head of the housing cumulative rotary hammer, the housing of the device is made of an ordinary drill pipe, the adapter is sealed with parts from the standard cumulative glass drill of the PKS type cover, gasket, bandage), it may be performed in any oil field. Together, a simple and highly effective device for increasing oil recovery is obtained.

Claims (2)

 1. DEVICE FOR INCREASING PRODUCTIVITY OF PLASTIC BY IMPLOSION METHOD, comprising a hollow body with an opening in the lower part closed by a destructible cover, and an electric detonator, characterized in that it is equipped with at least one damper with an opening installed in the housing above the electric detonator and dividing its cavity into individual cameras with the possibility of their communication, and the diameter of the holes in the damper is less than the diameter of the holes in the housing.  2. The device according to claim 1, characterized in that the diameter of the holes of the dampers is reduced from lower to upper.

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