RU206678U1 - MECHANICAL WELL CLEANING DEVICE - Google Patents

Abstract

The utility model relates to the field of oil and gas production, namely to devices for cleaning wells, and can be used to normalize the bottom of wells complicated by proppant plugs after hydraulic fracturing, cement crusts, foreign objects (fastening belts, bolts, wire) in combination with low reservoir pressure. The mechanical well cleaning device consists of a tubing string, a depression chamber located below the tubing string, and consists of a hydraulic cylinder with a piston having two built-in check valves, the device also contains a slurry receiver with a check valve-gate, consisting of pumping pipes -compressor and located under the depression chamber, a crown fixed from below on the slurry receiver, and a drain valve located above the depression chamber in the tubing string. The technical result is to improve the efficiency of cleaning wells with low reservoir pressure. 2 c.p. f-ly, 1 dwg.

Description

The utility model relates to the field of oil and gas production, namely, devices for cleaning wells, and can be used to normalize the bottom of wells complicated by proppant plugs after hydraulic fracturing, cement crusts, foreign objects (fastening belts, bolts, wire) in combination with low reservoir pressure.

Low reservoir pressure does not allow cleaning the bottom of the well using flushing due to the absorption of flushing fluid by the formation.

A device for cleaning a well by flushing the bottomhole with water is known from the prior art (Bukhalenko E.I., Abdullaev Yu.G. "Technique and technology for flushing wells." - M .: Nedra, 1982, p. 67-83), injected from the surface along tubing string (tubing). The device includes a mobile pumping unit, a lifting unit for running pipes, a tubing string and a tip attached to the end of the tubing. The disadvantages of this device are associated with the need to use a mobile pumping unit, low efficiency due to the absorption of drilling fluid by the formation and, most importantly, with the negative consequences of creating excessive pressure on the reservoir, leading to its pollution and clogging by the products of plug destruction.

Known technological complex for drilling and depression cleaning of a sand plug (patent RU 131061, publ .: 08/10/2013 Bull. No. 22), which contains a drilling device, a depression device and a device for regulating the air flow. The drilling device, which serves for drilling out sand plugs, contains an inner cutter, a housing, a spring pusher, a bearing assembly, an outer cutter, and a screw auger. The screw auger allows the drilled sand plug and cuttings to be transported, which ensures their uninterrupted movement into the tubing container. The depression device contains a fluid and sludge flow rate regulator, a check valve, a bypass valve, and a whipping valve. Due to the differential hydrostatic pressure (depression), the depression device tightens the drilled sand plug with cuttings. The air flow control device, consisting of a hose and a ball valve, serves to optimally store the depression energy. When the ball valve is closed, the air outlet slows down, which makes it possible to increase the operating time of the technological complex as a whole. The disadvantage of the device is that in wells with low reservoir pressure, the formation due to the absorption of fluid in order to create an acceptable depression for the operation of the device requires constant fluid addition. In this case, the bottomhole zone becomes polluted and clogged with the products of the destruction of the plug. Also, the disadvantage of the device is the need for multiple descents of the thief, which takes a lot of time.

The closest in technical essence is a hydraulic complex for cleaning deep wells (patent RU 2173380, publ .: 09/10/2001 Bull. No. 25), containing a thief, in the body of which a hollow rod is located, a plunger pump, having injection cavities and forming a single injection channel connected to the tubing string, and a receiving chamber, including a receiving cavity and a valve in the form of a damper, the complex additionally contains a container with a sludge-collecting cavity connected to the receiving chamber and to a plunger pump, forming a single collecting channel with the suction and inter-valve cavities of the pump, communicated with the intake chamber when the pump discharge valve is closed and the pump suction valve and the intake chamber valve flap are open, and communicated with the discharge channel, the hollow thief rod and the tubing string with the pump discharge and suction valves open, the thief valve and the intake valve damper. The disadvantage of this technical solution is the excessively complex design, which reduces the reliability of the device.

The problem to be solved by the claimed utility model is the development of a mechanical well cleaning device with a simple design and capable of quickly and efficiently cleaning a well.

This problem is solved by the fact that the mechanical well cleaning device consists of a tubing string, a depression chamber located below the tubing string, and consists of a hydraulic cylinder with a piston having two built-in check valves, the device also contains a slurry receiver with a check valve - a gate, consisting of tubing pipes and located under the depression chamber, a crown fixed to the bottom of the slurry receiver, and a drain valve located above the depression chamber in the tubing string. The crown is made with teeth. The teeth of the crown are reinforced with carbide overlay.

The technical result is to increase the efficiency of cleaning wells with low reservoir pressure.

The essence of the utility model is illustrated by a figure that shows the device in section, where:

1 - hydraulic cylinder,

2 - piston,

3 - check valve in the piston,

4 - check valve in the hydraulic cylinder,

5 - check valve in the crown,

6 - crown,

7 - drain valve,

8 - tubing pipes,

9 - sludge receiver.

The mechanical well cleaning device consists of a tubing string (tubing) 8, a depression chamber consisting of a hydraulic cylinder 1 with a piston 2 with built-in check valves 3 and 4. Below the depression chamber there is a slurry receiver 9, consisting of tubing pipes, then a return shut-off valve 5 and crown 6. Above the depression chamber there is a drain valve 7.

The hydraulic cylinder is a honed tube, with couplings at the ends, limiting the working stroke of the piston. The piston is made of two parts: the head of the piston, tightly fitting to the inner surface of the hydraulic cylinder, and the rod connecting the depression chamber with the tubing string through a check valve.

Check valves in the depression chamber and crown are a housing in which a shut-off element (steel ball) is located. The body has a spherical groove (saddle), when adjoining to which the ball hermetically closes the axial through hole in the body. A pin located across the body prevents the ball from falling out of the valve. Check valves 3 and 4 are located above and below the hydraulic cylinder.

The bit is made with teeth, reinforced with carbide surfacing for increased wear resistance, and is fixed from the bottom to the slurry receiver.

The drain valve is located above the depression chamber in the tubing string.

When cleaning the bottom of the well, the device goes down to the bottom (plug), and is filled with well fluid. Further, due to the downward and upward translational movements, the crown 6 loosens the top layer of the cork. During the upstroke, piston 2 moves out of cylinder 1 by the amount of stroke, while valves 3 and 4 are closed due to gravity (the pressure of the liquid column is higher than the valves) and a depression is created in the chamber, which causes the shutter valve 5 to open and the liquid is sucked from the bottomhole zone together with the products of cork destruction. During the downward stroke, the piston 2 enters cylinder 1, the gate valve 5 closes due to the compression of the liquid in the sludge receiver and the depression chamber, and prevents the elements of the plug, sludge from the sludge receiver 9. Valves 3 and 4 open, letting the liquid from the chamber higher through the tubing pipes ... The cycle is repeated until the bottomhole zone of the well is completely cleaned. The length of the sludge receiver 9 is selected when assembling the assembly, depending on the size of the plug. Excess fluid during operation is drained back into the well through the drain valve 7.

Thus, the claimed technical solution: differs in simplicity and efficiency in work, which is confirmed by experimental industrial tests.

Claims (3)

1. A mechanical well cleaning device containing a depression chamber, characterized in that the depression chamber consists of a hydraulic cylinder with a piston having two built-in check valves, the device also contains a slurry receiver with a check valve-gate, consisting of tubing pipes and located under the depression chamber , a crown attached to the bottom of the sludge receiver, and a drain valve located above the depression chamber. 2. A mechanical well cleaning device according to claim 1, characterized in that the crown is made with teeth. 3. A mechanical well cleaning device according to claim 2, characterized in that the teeth of the crown are reinforced with hard-alloy surfacing.

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