RU2471966C1 - Well cleaning and operation device - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device includes electric centrifugal pump suspended on tubing string, which are connected to each other by means of starting clutch, in the wall of which aerators are provided, which connect the channel of tubing to annular space of the well shaft and shutoff with a hollow shutoff valve moved along tubing string by means of a rope controlled from the well head. External surface of shutoff valve and mounting surface of starting clutch, at least on the length of aerator cross section, are conical and have angles corresponding to each other.

EFFECT: shortening the time required for placing of well on production.

2 cl, 2 dwg

Description

The invention relates to the oil industry and can be used for pre-cleaning wells from heavy downhole fluid.

A device for operating and cleaning a well is known, comprising a hollow rod, a check valve, a housing connected to a shank, a filter equipped with a bottom and a packer, including an expanding cone inserted into it and connected to the hollow rod with a cylindrical lower part that is telescopically inserted into the housing limited movement down and fixed relative to the housing by a shear element. The non-return valve is installed in the shank below the filter and is made in the form of a poppet valve. The valve seat is made with the possibility of tight interaction with the end nipple, lowered on the column of process pipes inside the device (patent RU No. 2398957 C1. Device for the operation and cleaning of the well. - IPC: Е21В 37/00. - 09/10/2010). A disadvantage of the known device is separate pre-start cleaning of the bottom-hole zone of the formation and cleaning of the bottom of the well from sludge, sand and dirt for subsequent commissioning of the well, which requires a large investment of time for putting the well into operation.

A gas lift valve assembly for a well is known, comprising a gas lift valve having a shutoff valve element located between the annular space and the tubing of the tubing, and an insulating element located on the inlet side of the shutoff valve element and adapted to descend into the well in the first position and in response to the value of the fluid pressure exceeding the threshold value, move to the second position (patent RU No. 2419715 C2. Gas-lift valve assembly. - IPC: Е21В 34/06. - 05.27.2011). This device is taken as a prototype.

The known device is designed for gas lift and is used to lift fluid from the well due to the energy of the gas supplied to the well under overpressure, and is not intended for pre-start cleaning of the well of heavy borehole fluid containing sludge, sand and mud, which is also filled to kill the well .

The main task, to which the claimed technical solution is directed, is to ensure pre-launch cleaning of the well from heavy borehole fluid containing sludge, sand and mud, which is also filled to kill the well, and subsequent commissioning of the well in one run of the tubing string .

The technical result achieved by the implementation of the proposed technical solution is to reduce the time for putting the well into operation due to aeration of heavy well fluid with inert gas and removing it from the well in suspension by an electric centrifugal pump.

The specified technical result is achieved by the fact that in the known device for cleaning and operating a well, comprising an electric centrifugal pump suspended on a tubing string forming an annular space with a wellbore and a gas lift valve assembly, according to the proposed technical solution,

the gas-lift valve assembly comprises a start-up coupling connecting the electric centrifugal pump to the tubing string, in the wall of which aerators are made, communicating the tubing channel with the annular space of the wellbore, blocked by a hollow shut-off valve that is moved along the tubing string by, for example a rope controlled from the wellhead;

the outer surface of the shutoff valve and the landing surface of the starting sleeve, at least along the length of the cross section of the aerators are made conical with corners corresponding to each other.

The analysis of the prior art cited by the applicant made it possible to establish that there are no analogs characterized by sets of features identical to all the features of the claimed device for cleaning and operating a well. Therefore, the claimed technical solution meets the condition of patentability "novelty."

The search results for known solutions in the art in order to identify features that match the distinctive features of the prototype of the features of the claimed technical solution have shown that they do not follow explicitly from the prior art. From the prior art determined by the applicant, the influence of the transformations provided for by the essential features of the claimed technical solution on the achievement of the specified technical result is not revealed. Therefore, the claimed technical solution meets the condition of patentability "inventive step".

Figure 1 shows a diagram of a device for cleaning and operating a well with an open gas lift valve assembly for aeration of a heavy well fluid with an inert gas; figure 2 is the same with a closed gas lift valve unit during operation of the well.

A device for cleaning and operating a well comprises an electric centrifugal pump 1, suspended on a tubing string 2, interconnected by a start clutch 3, in the wall of which aerators 4 are made, communicating the channel 5 of the tubing 2 with the annular space 6 of the wellbore 7, blocked by a shut-off valve 8 with a cavity 9 that is moved along the string of tubing 2 by, for example, a rope 10 controlled from the wellhead. The outer surface of the shut-off valve 8 and the seating surface of the start-up clutch 3, at least along the cross-sectional length of the aerators 4, are conical with corners corresponding to each other (FIGS. 1 and 2).

A device for cleaning and operating a well works as follows.

An electric centrifugal pump 1 with a tubing string 2 connected by a start-up sleeve 3, with a shut-off valve 8 and a cable 10 located inside the channel 5 of the tubing string 2 is lowered into the wellbore 7, filled with heavy borehole fluid, including sludge , sand and dirt, to the depth of the borehole shutter (not shown conditionally), forming an annular space 6 with a heavy borehole fluid between them. The shut-off valve 8 through the rope 10 is displaced from the starting sleeve 3 along the string of tubing 2, thereby freeing the aerators 4 of the starting sleeve 3 of the gas lift valve assembly. Then, inert gas under positive pressure is supplied to the channel 5 of the tubing string 2 by the compressor. Inert gas passes through the channel 5 of the tubing string 2, flowing around the shut-off valve 8, enters the cavity 9 of the start-up sleeve 3, from which through the aerators 4 passes into the annular space 6, a heavy borehole fluid is bubbled through it, forming in the annular space 6 by inert gas aeration gas-liquid suspended mixture with a specific gravity significantly less than the specific gravity of a heavy well fluid. After that, the shut-off valve 8 is displaced along the string of tubing 2 by means of a cable 9 controlled from the wellhead and lowered by the conical surface of the shut-off valve 8 into the conical landing surface of the start-up clutch 3, thereby closing the aerators 4 in it, stopping the access of inert gas to annular space 6 with a gas-liquid suspended mixture. At the same time, the supply of excess pressure to the channel 5 of the tubing string 2 from the compressor is stopped and the operation of the electric centrifugal pump 1 is turned on, which pumps the gas-liquid suspended mixture from the annular space 6 of the wellbore 7 through the cavity 9 of the shut-off valve 8 through channel 5 in the tubing string 2 out of the well before the appearance of oil.

This ensures pre-start cleaning of the well from heavy borehole fluid containing sludge, sand and mud, which is also filled to kill the well, and subsequent commissioning of the well in one run of the tubing string with an electric centrifugal pump.

Claims (2)

1. Device for cleaning and operating a well, comprising an electric centrifugal pump suspended on a tubing string forming an annular space with a wellbore and a gas lift valve assembly, characterized in that the gas lift valve assembly comprises a start-up coupling connecting the electric centrifugal pump to the pump string -compressor pipes, in the wall of which aerators are made, communicating the channel of the tubing with the annular space of the wellbore, blocked by a hollow shut-off valve, moved along the string of tubing by, for example, a rope controlled from the wellhead. 2. The device according to claim 1, characterized in that the outer surface of the shut-off valve and the seating surface of the starting clutch, at least along the length of the cross-section of the aerators, are conical with corners corresponding to each other.

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