RU2376456C1 - Well swabbing equipment - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: invention related to oil-and-gas production can be used for well with viscous fluid swabbing. Equipment contains swab with load under. The load is screw shaped, connected with central rod of swab via sleeve and made of steel rod with welled on it helical thickening which is pointed in the end.

EFFECT: well swabbing operation efficiency increase.

1 dwg

Description

The invention relates to the oil industry and may find application in swabbing a well.

A known installation for oil production from low-yield wells (US patent No. 5097901, class 166/68 of 03.24.1992), containing a winch with a rope mounted on a transport base with a power engine, on the free end of which is mounted a swab having a hollow body with external sealing elements that contact when lifting products from the well with the inner surface of the production casing of the well, equipped with a non-return valve installed in the housing and an attached load. The installation contains a vehicle At the base, a mast with a guide roller for the rope, connected to the lubricator for the swab with the load, at the top on the lubricator is a node for sealing the rope, and in the lower part the lubricator is equipped with a unit for connecting to the production casing of the well. The installation is equipped with a tank for collecting and transporting well products, connected by a pipeline through a non-return valve with a lubricator.

A disadvantage of the known installation is that when swabbing a well with viscous oil, it is not possible to submerge the swab into the well to the required depth and perform the swab operation.

Closest to the proposed invention in technical essence is an installation for the production of sulphurous oil containing a winch with a rope mounted on a transport base with a power engine, at the free end of which there is a swab loaded with cargo, lowered into the well through a lubricator with a rope sealing unit mounted on the mast mouth with a guide roller for the rope, a collection tank for the production of the well, equipped with a breathing channel and connected through a non-return valve, and stop valves with a lubricator, moreover, The wab is made in the form of a hollow body with channels, a valve inside and with sealing elements installed outside. The installation is equipped with an additional tank with a neutralizer of harmful impurities in petroleum gas, tightly connected at the inlet through the shut-off valve with the breathing channel of the collecting tank and through the shut-off valve and gas flow regulator with a lubricator, and at the outlet with neutralized gas scattering candles, the additional the tank is equipped with a dispersant, and the outlet is equipped with a spray chipper, while the hollow body of the swab is equipped with a constriction inside, and the valve is made in the form of a coaxial mounted in the body an axial axial movement of the rod with a thickening made with the possibility of tight interaction from below with narrowing of the body, the rod being connected from above to the rope, and from below - pivotally with the load (RF Patent No. 2334080, class Е21В 43/00, published on 2008.09.20 - prototype) .

The known device contains a load of the original design, however, this does not allow to lower the swab into the well with a viscous fluid (oil) to the required depth and perform the swab operation.

The proposed invention solves the problem of enabling swabbing of a well with a viscous fluid.

The problem is solved in that the device for swabbing a well, including a swab with a load under the swab, according to the invention as a cargo contains a screw with a pointed end.

The screw is made of steel and has a length of 1.5 to 1.8 m, a diameter of 22 to 32 mm, a number of grooves of 10 to 15, a groove height of 4 to 8 mm, a groove tilt of 55 to 80 degrees, a groove tilt direction ( right or left) does not matter.

The screw may be coated with a release coating.

SUMMARY OF THE INVENTION

When a swab is lowered into a well filled with a viscous fluid, difficulties arise with the passage of a swab to the bottom. Swab cannot overcome the resistance of a viscous fluid and gets stuck in the well before reaching the bottom. Swabbing such a well is practically impossible. A viscous fluid in which similar difficulties arise is a fluid with a viscosity of more than 500 cps. This may be a viscous oil, a fluid with thickening deposits such as paraffins, asphaltenes, etc. The proposed invention solves the problem of enabling swabbing of a well with a viscous fluid. The problem is solved by the device shown in the drawing.

The drawing shows the claimed device for swabbing a well (swab),

where 1 is the central rod (mandrel), 2 is the thread, 3 is the coupling, 4 is the screw, 5 is the cuff of elastic material, 6 is the stop, 7 is the saddle. Elements 1, 4, 6, 7 are elements of a classic swab. Elements 2, 3, 4 are additional elements according to the proposed invention.

A metric thread 2 is machined on the mandrel 1, onto which a screw 4 is screwed through the sleeve 3, which is a steel rod with a spiral thickening welded on it. The screw 4 increases the weight of the swab and due to its design features, i.e. the presence of a pointed end and spiral welded thickening, makes it easy to penetrate into a highly viscous environment.

When lowering the swab equipment on the cable, the cuff 5, dressed on mandrel 1 and having an outer diameter (for example, 54 mm) less than the inner diameter of the tubing string (for example, 62 mm), is in a free state and moves along mandrel 1 from the lower saddle 7 to the upper stop 6 and vice versa. When immersed in the borehole fluid, the swab cuff 5 occupies the upper position, while the fluid passes through the annular space between the outer wall of the cuff 5 and the inner wall of the tubing string and the inner cavity of the cuff 5. In this case, the screw 4 serves as an additional load and baking powder of viscous fluid and facilitates the passage of the device to the bottom of the well.

When lifting due to the liquid column, the cuff 5 deforms, which takes the inner diameter of the tubing string, the liquid column presses on the cuff 5, which abuts the lower seat 7, and due to the creation of a sealing “tampon”, the liquid above the cuff 5. The device performs its necessary function of cleaning the tubing string from mechanical impurities, scale, etc.

The most optimal screw parameters for solving the task are as follows: the screw is made of steel and has a length of 1.5 to 1.8 m, a diameter of 22 to 32 mm, the number of grooves from 10 to 15, the height of the grooves from 4 to 8 mm, the slope grooves α from 55 to 70 degrees to the generatrix of the wall (in the drawing it looks like an axis) of the steel rod. The lower end of the auger is pointed with a taper angle β ranging from 45 to 60 degrees to the axis of the rod.

The screw can be coated with a release coating, for example polyethylene, polypropylene, fluoroplastic, epoxy coating, etc.

Using the indicated construction of the swab makes it possible to carry out work in a highly viscous medium without the use of special steaming equipment, reducing the time for swabbing operations, reducing the number of accidents caused by a broken cable and falling downhole equipment to the bottom of the well.

In addition, the auger allows you to loosen and pass through thick layers, clean the bore in the tubing string, thereby allowing the geophysical instruments to be subsequently launched to control the well without involving the underground repair team.

The use of a screw in the design of the swab will allow:

- save money by eliminating the “idle” passages of geophysical parties, reduce the cost of special equipment;

- not to involve teams of underground repairs due to the "failure of the geophysical instrument";

- save the environment;

- timely conduct geophysical surveys;

- carry out work in a highly viscous environment without the use of special equipment for lifting and steaming the tubing string;

- reduce the time for swabbing operations;

- reduce the number of accidents caused by wire breakage and the fall of downhole equipment at the bottom of the well.

Claims (1)

A device for swabbing a well, including a swab with a load under the swab, characterized in that the load is made in the form of a screw connected via a sleeve to the central shaft of the swab and consisting of a steel rod with a spiral thickening welded on it and a pointed end, while the length of the screw is in the range of 1.5-1.8 m, the diameter of 22-32 mm, the number of grooves 10-15, the height of the grooves 4-8 mm, the angle of inclination of the grooves to the generatrix of the wall of the rod 55-70 °, the angle of sharpening of the screw to the axis of the rod is within 45-60 °.