RU1781417C - Process of decomposition of paraffin-resinous deposits and device to implement it - Google Patents

Description

1

(21) 4808938/03 (22) 02.04.90 (46) 12.15.92. Bull. №46

(71) Ivano-Frankivsk Institute of Oil and Gas

(72) D.P. Kudin, N.V. Savitsky, O.I. Kudina and O.N. Kutiev

(56) Copyright certificate of the USSR No. 1270298, cl. E 21 B 37/06, 1986.

USSR copyright certificate Mg 1234593, cl. E 21 B 37/06. 1986.

USSR copyright certificate Mg 310031. cl. E 21 B 37/06. 1971.

(54) METHOD FOR DESTRUCTING PARAFFIN-RESINOUS DEPOSITS AND DEVICE FOR ITS IMPLEMENTATION

(57) Use: in the oil and gas industry for the destruction of paraffin-tar deposits in the annulus or in the risers of wells in the production of paraffin-containing oil. SUMMARY OF THE INVENTION: A well is cleaned by injecting a vapor-air mixture with an alternating cycle of ejection and vibration, followed by withdrawal of the well medium by creating a vacuum using an ejector. The device includes wellhead equipment, ejectors for pumping the mixture and creating a vacuum in the well, and a vibrator mounted in parallel with one of the ejectors with the possibility of periodically connecting the supply system. 1 s.p. f-l, 1 ill.

The invention relates to oil production, to the operation of oil wells producing paraffinic oil, during the operation of which paraffin-resinous substances (PSV) are deposited.

Well-known methods for de-paraffinization of wells, which include injecting hot oil into the well and pumping it until the PSV deposits are completely eliminated (1) or injecting hydrocarbon gas, keeping the well under pressure and drastically reducing it for oil removal and (PSV).

A known device for dewaxing oil wells, selected as a prototype of the invention, comprises a heater, a pump and a gas separator mounted on self-propelled vehicles.

A disadvantage of the known methods and device (unit) is low productivity, because the small flow area of the paraffinized riser pipes cannot provide sufficient heating of the sediments, breaking of their bonds and removal of the medium to the wellhead. In the absence of circulation in the well, this device is generally not effective. The use of hydrocarbon gases for dewaxing of wells is complicated by the need to utilize them to avoid disturbing the ecology of the production area.

The purpose of the invention is to increase the efficiency of destruction and removal of PSV from the well, to restore the circulation of the well, and also to create conditions for preserving the ecology of the production area.

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This is achieved by the fact that a mixture of superheated steam with air from pressure sources is supplied to lifting pipes (PT) or annulus depending on the method of oil production. Under the action of the mixture, the upper level mark of the oil in the well is pushed down (in the presence of circulation of the gfiyem reservoir), superheated 1ap heats the liquid and PSV and promotes gas dissolution.

Gas in the form of tiny bubbles is taken inside the PSV and liquid deposits and dissolves in them until saturated. For saturation, sufficient hydronic time is required, which depends on the pressure and temperature of the mixture, which in turn affect the rate and intensity of gas penetration into the volume of the substance. These parameters are determined empirically depending on the characteristics of the well during the implementation of the technology.

In order to intensify the dissolution of the gas and enhance the heat transfer, a vibrator is switched on periodically at the pressures close to the optimal ones.

After saturation of the liquid and PSV with gas, a sharp decrease in pressure is carried out by maximum depressurization of the well. In order to intensify well cleaning after reducing the pressure at the wellhead to atmospheric, an ejector is used to work with which a vacuum is obtained to more thoroughly clean the well. Then the cycle is repeated 5-16 times.

The salient features of the invention are as follows: a mixture of air and steam is pumped into the well; an ejector is used to mix steam and air; a vibrator is used to intensify the dissolution and heating of the medium in the well; an ejector is used to create a vacuum in the well after a sharp decrease in pressure; the device is mounted on a mobile platform, and is equipped with a reservoir to maintain environmental cleanliness in the well area.

The drawing shows the design of a device for implementing the proposed method.

On the platform 1, a vibrator 2, ejectors 3 and 4, valves 5-9, a bypass valve 10, a waste fluid reservoir 11 connected by a pipe network 12 are mounted to provide the technology.

The operation of the device is carried out as follows.

A compressor is connected to the nozzle 13, and a para-producer for installation (PPU) is connected to the nozzle 14. With open shutters 8 and 7 from pressure sources through the ejector 3, the mixture is pumped under pressure into the PT 15 of the well 16. The superheated mixture extrudes the fluid from the PT in the presence of circulation, releasing the PSV from the fluid, heats them, and the air under

0 pressure destroys the structural bonds of PSV in the fluid volume, decreasing its viscosity. After reaching the predetermined pressure and holding for a time sufficient to dissolve the air using valve 10 and valve 9, a sharp decrease in pressure is produced. For a short time, air sharply increases in volume, is ejected from the well, the removal of liquid and deposition of PSV into the reservoir of device 11. After the pressure in the well drops to further reduce it to vacuum, the shutter 5 and 8 are closed; and the valve 9 is opened, and from the PUF is fed to the ejector 4 to create a vacuum in the well5. Subsequently, when the pressure in the borehole is close to optimal, the valves 6,7,8 are closed and air is supplied to the borehole through a vibrator 2, subjected to vibration of the PT 15 and the mixture supplied to the well 16, to intensify the dissolution of air and the breakdown of structural bonds of PSV deposits . Then, the steam-air mixture injection cycle, depending on the state, is repeated 5-10 times until complete cleaning

5 PT or annular space from PSV deposits.

The use of the invention in comparison with known methods and devices prevents transmission

0 wells for overhaul, speed up the destruction of paraffin-tar deposits or plugs, reduce the amount of materials, chemicals, increase oil production, save

5 ecology of the field and reduce the number of workers.

Claims (1)

SUMMARY OF THE INVENTION 1. A method for destroying paraffin-tar deposits, comprising periodically injecting a gas-liquid mixture into a well, keeping the well under pressure and then reducing it, characterized in that, in order to increase the effectiveness of the destruction due to the intensification of the destruction and removal of paraffin-tar substances , a mixture of air and steam is used as a gas-liquid mixture, periodic injection is carried out with an alternating cycle of ejection and vibration exposure when the mixture is fed into the well, and the wells are withdrawn constant of the medium is carried out creating a vacuum in the hole by ejecting borehole environment. 2, A device for destroying paraffin-tar deposits containing wellhead equipment, a transport unit with a gas-liquid mixture supply system mounted on a platform, characterized in that it is additionally equipped with reservoirs placed on the platform, two ejectors and a vibrator, moreover, one of the ejectors and the vibrator are installed parallel to each other between the supply system and the wellhead equipment with the possibility of connecting them in turn, and the second ejector is connected with the wellhead equipment and the reservoir to create a vacuum in the well during the selection of the well medium, the gas-liquid mixture supply system and the selection system the borehole medium is interconnected and connected to the borehole through a single pipeline.