RU2188303C2 - Device for building up of differential pressure onto formation - Google Patents

Abstract

FIELD: oil producing industry. SUBSTANCE: device may be used as equipment for cleaning of bottom-hole formation zone from drillings, sand, paraffin, resins and other accumulations difficult to be removed, and creation of oil hydroseal against producing formation. The device has body with two rows of radial channels separated by solid transverse partition. In initial position, channels are closed by movable bushing. Bushing is engageable with packer and has cylindrical hollow on internal surface. From below, body is connected with nipple-shank by means of shear member. Nipple-shank is installed on packer which is stationary. Nipple-shank has check valve and conical funnel in upper part. Body is provided with centralizer and made with limiting shoulder. In operating position, limiting shoulder is engageable with bushing on conical funnel. Body serves as depression and drillings receiving chamber, and tubing is used as means for device lowering and lifting. EFFECT: simplified design of device and extended functional potentialities. 1 dwg

Description

 The invention relates to the oil industry and can be used as equipment for cleaning the bottom-hole zone of the formation and the bottom of the wells from sludge, sand, paraffin, resins and other hard to remove deposits and reduce cone formation.

 A device for cleaning wells by the implosion method is known, consisting of an implosion chamber, which is attached to a wireline cable through an electronic unit and a geophysical headgear. A load rod is suspended in the upper part of the implosion chamber, and in the lower part there is a stepped rod connected to the centering sleeve with the possibility of overlapping cams in the transport position and interacting with the weight rod to release the glass from engagement with the sub [1].

The disadvantages of the device are:
- low efficiency of the device, due to the fact that when you open the implosion chamber, the latter will be filled mainly with well fluid, and not with sludge and formation fluid;
- high cost of the device, due to the use of electronic equipment and wireline cable.

 Closest to the technical nature of the proposed device is a depression well cleaning device containing a housing, a depression and sludge receiving chamber, a packer, a means for lowering and lifting and sealing elements [2].

The existing disadvantages of the device are:
- the complexity of the design and the resulting metal;
- limited volume of the sludge receiving chamber and, as a result, the need for repeated descents of the device;
- one-time use, due to the fact that at the time of creation of the implosion effect, a piston may strike the plug valve and destroy it;
- limited functionality;
- the device allows you to achieve a temporary effect, because after it rises, the pollution in the wellbore will again enter the pores and channels of the reservoir and reduce its permeability.

 The objective of the invention is to provide a device of less complex design, reusable, with almost unlimited volume sludge collection chamber and the expansion of functionality.

 This problem is solved by the proposed device, comprising a housing, a depression and sludge receiving chambers, a packer, a means for lowering and lifting and sealing elements.

 New is that the housing is equipped with a centralizer and is made with a ledge-limiter and two rows of radial channels separated by a blind transverse partition, which in the initial position are covered by a sleeve mounted on the housing with the possibility of longitudinal movement and interaction with the packer and made with a cylindrical selection on the inner surface and equipped with a nipple-shank with a check valve and with a conical socket in the upper part, which is connected telescopically with the body using a cut-off ele ment, and in the working position, the ledge-limiter of the body interacts with the sleeve and with the conical socket of the nipple-shank, and the latter with the packer; as a depression and sludge-receiving chambers, a housing and means for lowering and raising the device are used.

 The drawing shows the proposed device in longitudinal section.

 It consists of a housing 1, in the upper part of which a centralizer 2 is installed, and two rows of radial channels 3 and 4 are made below. A transverse blind partition 5 is installed between the latter inside the housing. The lower section of the housing 6 has a smaller diameter, made with a ledge-limiter 7 and telescopically enters the nipple-shank 8 with a check valve 9. In the initial position, the radial channels 3 and 4 are blocked by a sleeve 10 mounted on the housing with the possibility of longitudinal movement and made with a cylindrical selection 11 on the inner surface awns. The upper end of the nipple-shank 8 has a conical socket 12, which it enters into the sleeve 10. The nipple-shank and the housing are interconnected by means of a shear element 13. The device contains a stationary packer 14. All mating surfaces are provided with sealing elements 15. The length of the nipple-shank 8 is taken from the condition that its end when installing the device in the well is below the perforations of the reservoir.

 The device operates as follows.

 Before the device is lowered into the well, the stationary packer 14 is lowered and installed above the reservoir 16. The device is then assembled on the tubing 17 is lowered into the well. In this case, the centralizer 2 eliminates the possibility of premature operation of the device and contributes to the accurate entry of the nipple-shank 8 into the passage channel of the packer. When the device is planted on the packer, the sleeve 10 rests on it, and the rest of the device continues to move down until the cone socket 12 fits into the cone groove 18 of the packer. With further movement of the housing downward, the sheared element 13 is destroyed and the ledge-limiter 7 is planted on the conical socket 12. At this moment, the rows of radial channels 3 and 4 communicate with each other in a cylindrical sample 11, and the inner space of the tubing is connected to the downhole space under the packer. And since the pressure inside the tubing is atmospheric, a significant depression is created on the formation. Under the influence of the difference in the pressure of pollution and sludge from the reservoir through the nipple-shank 8, the radial channels 3 and 4 fall into the upper part of the body and then into the tubing. After the operation to create depression on the formation is completed, the device is raised to the surface. In this case, the sleeve 10 under its own weight falls on the ledge-limiter and overlaps the upper row of radial channels. The packer and nipple shank with a check valve remain in the well.

 Depression on the formation can be controlled by pouring the calculated volume of fluid into the tubing.

 Then the pump is lowered into the well and development and operation are carried out in the usual manner.

 The proposed device is much simpler in design than the known one. In the process, when creating an implosion effect, the nodes and parts of the device are not subject to destruction, due to which reusability is achieved. Unlimited slurry chamber volume reached. After lifting the device, the producing formation is isolated from the wellbore by a packer and a nipple-shank with a non-return valve and therefore the negative effect on the formation of water, kill fluid and contaminants in the wellbore is eliminated. In addition, the presence of a nipple-shank installed below the perforation holes helps to create a hydraulic shutter from oil opposite the productive formation for the entire time of operation, and thereby the percentage of water production from the bottom of the productive formation decreases sharply.

Sources of information
1. The analogue is the patent of the Russian Federation 2086753, MKI 6 E 21 V 37/00, 1977.

 2. The prototype is RF patent 2099506, MKI 6 E 21 B 37/00, 1977.

Claims (1)

 A device for creating depression on the formation, comprising a housing, a depression and sludge receiving chamber, a packer, a means for lowering and lifting and sealing elements, characterized in that the packer is stationary, the housing is equipped with a centralizer and is made with a ledge-limiter and two rows of radial channels separated between themselves a blind transverse partition, which in the initial position is blocked by a sleeve mounted on the housing with the possibility of longitudinal movement and interaction with the packer and made with a cylindrical a sample on the inner surface, and is equipped with a nipple-shank with a check valve and with a conical socket in the upper part, which is telescopically connected to the body using a sheared element, and in the working position the ledge-limiter of the body interacts with the sleeve and the conical socket of the nipple-shank, and the last - with a packer, as a depression and sludge-receiving chambers, a housing and means for lowering and raising the device are used.