RU30387U1 - Tubing scraper - Google Patents

Description

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Tubing scraper

The utility model relates to the oil and gas industry and can be used in the production of liquid and gaseous hydrocarbons for cleaning the inner surface of tubing from asphalt-resinous paraffin (paraffin hydrate or hydrate-paraffin) deposits by an upward flow of liquid or gas.

Various methods are used to prevent deposits and their removal from the walls of pumping pipes (mechanical, thermal, chemical), and they are cleaned with a standard mechanical scraper, flushed with hot oil, a heating projectile, pumped chemical solutions, etc.

The most cheap way to date is the mechanical method of removing hydrate-paraffin formations.

A device for cleaning wells is known from the prior art, including a housing with a valve assembly, sealing elements mounted on the spring sleeve, interconnected by means of a ring with channels that communicate with the cavity above them with a cavity under the valve assembly (see SU 596710, 03/05/1978 ) The disadvantage of this device is that due to its design features, it will not be able to work effectively in wells that tend to intensive hydrate-paraffin deposition, since there are no cutting edges on the outer surface and, in addition, the valve has a taper which, when moving upwards, will collect and seal the deposits from the walls of the tubing, which ultimately will stop the valve and stop the well.

ЕВВ 37/02 A device is also known for cleaning oil pipes from

paraffin deposits (see SU 1102899, 12/10/1982), which is a set of longitudinal scrapers in the form of harpoons on an axis connected to the rope.

The disadvantage of this device is that when passing through narrowed areas it can get stuck and cause an emergency. In addition, when used in directional wells, this device, pressing against the wall of the well, does not provide high-quality cleaning of the walls of the production string.

The closest analogue of the claimed utility model adopted for the prototype is a scraper for cleaning tubing with an upward flow of gas-liquid mixture (see RU 2158355, 10.27.2000), having a composite structure, the lower part of which is a sleeve, with channels on the outside the side surface, made at a certain angle to the generatrix of the side surface, creating a torque when the fluid passes through them, while rotating the sleeve, the edges of its side channels essentially represent p cutting elements and act as milling cutters, cleaning the internal cavity of the tubing, when the scraper moves up and down.

However, as a result of rotation of the cutting element in one direction, said scraper does not provide high quality pipe cleaning, which leads to a narrowing of the pipe bore and a decrease in labor productivity, as well as additional costs for equipment repair.

The objective of the utility model is to increase the efficiency of production wells by improving the quality of mechanical cleaning of the inner surface of tubing during operation, which ultimately ensures an increase in daily oil production and a decrease in the cost of major repairs.

2

The problem is solved by developing a scraper, including a cutting element mounted on the shaft, mounted with the possibility of rotation under the influence of a moving fluid flow, while the cutting tool is made in the form of at least two mills mounted for rotation in opposite directions. The cutters are preferably made with multidirectional helical blades and mounted at a distance from each other. The cutting edges of the helical blades of each cutter preferably lie on a spherical surface. Milling cutters can be mounted on the shaft using angular contact bearings. The front end of the scraper may have a guide shaft rigidly connected to the shaft.

Pa Fig. 1 shows a diagram of a scraper, where 1 is a shaft, 2 are milling cutters with multidirectional helical blades, 3 is a bushing, 4 are radial bearings, 5 is a guide shank, 6 is a nut, 7 a lock nut; figure 2 - appearance of the cutter.

The scraper for cleaning tubing contains milling cutters 2, which are turbines with a diameter of 50-55 mm with multidirectional screw blades and freely mounted on the shaft 1 using radial support bearings 4, providing easy rotation when an upward flow of liquid (oil, gas condensate, water) or gas on the blades of the cutters 2. Between the cutters 2 is mounted freely relative to the shaft 1 of the sleeve 3, providing a predetermined distance between the cutters. Each cutter 2 has a spherical shape, i.e. the cutting edges of the screw blades of each cutter 2 lie on a spherical surface, so that when the cutter rotates, the cutting edges describe a spherical surface, more precisely, the part of the sphere bounded by the end surfaces of the cutter 2. 3

The helical blades of the milling cutters 3 are made in different directions, so that when exposed to the flow of the milling cutters 2 rotate in different directions, which improves the quality of cleaning 1ZHT.

At the front end of the shaft 1 of the scraper, a guide shank 5 is rigidly fixed, which facilitates the movement of the scraper when it moves inside the pipe. From the opposite end of the shaft 1, a nut 6 and a lock nut 7 are placed, which are connected to a load of 0 42 and 0 36 mm and are fixed to the wire.

The work of the scraper is carried out by lowering or lifting it on a wire of 0 1.8-2.2 mm in a working well, provided that the moving fluid stream spins the turbines (cutters 2) in different directions. The rotation of the wire in this case does not occur, while the sharp cutting edges of the cutters 2 conduct mechanical cleaning of the inner part of the tubing.

The cutting element - mill 2 - is made in the form of a sphere for the following reason.

It is necessary to work in wells with low flow rates and large angles of inclination. It was experimentally established that the oncoming flow is not always enough to unwind the cylindrical cutter and make it work on the entire cutting plane, and the sphere is untwisted instantly, and the length of the cutting edge is reduced to a minimum value.

Using the above design of the scraper allows mechanical cleaning of the inside of the tubing to the state of "artillery shine.

A clear periodicity of well operations reduces the cost of overhaul of wells, increasing the daily oil production in the field to 20%.

Claims (6)

1. A scraper for cleaning tubing, including a cutting element mounted on the shaft with the possibility of rotation under the influence of a moving fluid flow, characterized in that the cutting tool is made in the form of at least two cutters installed with the possibility of rotation in opposite side. 2. The scraper according to claim 1, characterized in that the cutters are made with multidirectional screw blades. 3. The scraper according to claim 2, characterized in that the cutting edges of the helical blades of each cutter lie on a spherical surface. 4. Scraper according to any one of claims 1 to 3, characterized in that the cutters are installed at a distance from each other. 5. A scraper according to any one of claims 1 to 4, characterized in that the cutters are mounted on the shaft using angular contact bearings. 6. A scraper according to any one of claims 1 to 5, characterized in that the scraper is provided with a guide shank rigidly connected to the shaft.