Filtration system for installation of electric submersible pump

Abstract

FIELD: oil producing industry.SUBSTANCE: invention relates to oil production using electric submersible pumps (ESP). The device contains a carrier pipe, equipped with a centralizer in the lower part and secured in the upper part through a submersible electric motor base, previously lowered and secured to the production string by a mechanical packer, on which a docking device and a tailpiece made of tubing are installed. The carrier pipe is equipped with two filters installed in series, each of which is fixed by means of upper and lower metal disks and clamps with screws. The filters are made in the form of truncated cones from metal mesh disks made of stainless wire. The larger base of each filter cone is oriented towards the wellhead, matches the internal diameter of the tail pipe and is equipped with a cuff with holes for the passage of liquid. The mesh size of the upper filter is set with a ratio of at least 3:1 in relation to the mesh size of the lower filter. The length of the carrier pipe and the number of disks in the filters are determined based on the condition of their complete placement in the tail pipe.EFFECT: reliability of the ESP during oil production in conditions with a high content of mechanical impurities is increased by improving the design of the filtration system, which ensures more efficient and long-term purification from mechanical impurities.1 cl, 1 dwg

Description

[0001] The invention relates to the oil producing industry, namely to the extraction of oil using electric centrifugal pump units (ESP) for the extraction of oil with a high content of mechanical impurities.

[0002] Operating production wells using ESPs is one of the primary methods of mechanized oil production both in the Russian Federation and abroad. Due to ongoing efforts to optimize production and reduce bottomhole pressure during ESP operation, one of the challenges is the high content of mechanical impurities in the extracted product, which leads to unstable ESP operation, reduced service life, and emergency shutdowns.

[0003] An adjustable filter for deep-well pumps is known (RU patent No. 122691, IPC E21B 43 / 08, published on 12 / 10 / 2012 in bulletin No. 34), comprising a perforated housing with a filter element, a channel for the passage of purified liquid, made in the form of a branch pipe located inside the housing, a disconnector separating the inlet part of the filter from the outlet, made in the form of a bell with a seal installed on it, the filter element is made in the form of a spring placed between support and control elements installed in the filter housing, and the bell is hingedly fixed on the upper end of the branch pipe with the possibility of rotation, while the seal is made in the form of a set of at least three elastic washers, the middle washer has an outer diameter smaller than the outer diameter of each of the extreme washers.

[0004] The disadvantage of this filter is its lack of reliability due to the risk of damage to the disconnector cuff when lowering the filter and low efficiency due to the use of a spring as a filter element, which cannot provide effective protection of the pump from mechanical impurities.

[0005] The FSD downhole disc filter is manufactured by Novomet LLC in Perm (link to the website: https: / / www.novomet.ru / rus / products-and-services / artificial-lift / solids-management / downhole-disk-filter / ?ysclid=mlsa8kvgc3259649225). The FSD filter consists of a perforated pipe and a permeable cylindrical packing composed of metal mesh discs concentrically mounted on the pipe. According to the illustration on the website, the FSD filter is attached to the ESP housing with a sub, which significantly limits its scope of application and complicates the ESP design.

[0006] The closest in design is a filter for an oil well (patent RU No. 200711, IPC E21B 43 / 08, published on 06.11.2020 in Bulletin No. 31), which includes a carrier pipe with a centralizer for hanging from below to a borehole pump, a set of horizontal packages with diameters exceeding the internal diameter of the production casing, filled with steel wire and intervalwise fixed on the carrier pipe, the horizontal packages are made with different sizes of cells formed by the wire, decreasing in the direction towards the wellhead, and the cell sizes are selected based on the ranges of change in the sizes of solid suspended particles in the well product.

[0007] The disadvantages of the existing solution include the low mechanical strength of the filter elements, leading to their destruction during the pumping process, as well as the insufficient filtration capacity of steel wire bags. The latter are characterized by the inability to achieve the required filtration fineness, which does not provide adequate protection for the pump from mechanical impurities, and the small filtration surface, which leads to their rapid clogging.

[0008] The technical result of the invention is to increase the reliability of the ESP operation during oil production under conditions of high content of mechanical impurities by improving the design of the filtration system, which ensures more efficient and long-term purification from mechanical impurities.

[0009] The technical result is achieved by a filtration system for installing an electric centrifugal pump, including a carrier pipe, equipped with a centralizer in the lower part, and secured in the upper part through a sub-assembly to the base of the submersible electric motor of the ESP.

[0010] What is new is that the filtration system is additionally equipped with a mechanical packer, which is pre-lowered and secured to the production string, on which a docking device and a liner made of tubing pipe are installed, the carrier pipe is equipped with two filters installed in series, each of which is fixed by means of upper and lower metal disks and clamps with screws, the filters are made in the form of truncated cones made of metal mesh disks made of stainless wire, and the larger base of the cone of each filter is oriented towards the wellhead, coincides with the internal diameter of the liner pipe and is equipped with a cuff with holes for the passage of liquid, while the mesh size of the upper filter is set with a coefficient of at least 3:1 in relation to the mesh size of the lower filter, the length of the carrier pipe and the number of disks in the filters are determined from the condition of their complete placement in the liner pipe.

[0011] The figure shows a diagram of the proposed installation, where the submersible electric motor is 1, hydraulic protection is 2, inlet module is 3, ESP pump sections are 4, tubing column is 5, check valve is 6, knock-down valve is 7, cable is 8, cuff with holes for liquid passage is 9, sub is 10, carrier pipe is 11, centralizer is 12, mechanical packer is 13, docking device is 14, shank is 15, upper filter is 16, lower filter is 17, upper and lower metal disks are 18, 19, clamps with screws are 20, production casing is 21, productive formation is 22.

[0012] The essence of the invention.

[0013] The filtration system for installing an electric centrifugal pump contains a supporting pipe 11, equipped with a centralizer 12 in the lower part, and secured in the upper part through a adapter 10 to the base of the submersible electric motor of the ESP 1.

[0014] Additionally, the filtration system is equipped with a mechanical packer 13, which is pre-lowered and secured to the production string 21, on which a docking device 14 and a tail 15 made of tubing are installed.

[0015] The carrier pipe 11 is provided with two filters 16, 17 installed in series.

[0016] Each of which is fixed by means of upper and lower metal disks 18, 19 and clamps with screws 20.

[0017] Filters 16 and 17 are truncated cones made of stainless steel wire mesh discs. The truncated cone shape of filters 16 and 17 increases the filtration area, while the metal mesh used for filters 16 and 17 ensures the precise filtration level required, unlike comparable filters.

[0018] Moreover, the larger base of the cone of each filter 16, 17 is oriented towards the wellhead (not indicated in Fig. 1, 2), coincides with the internal diameter of the tail pipe 15 and is equipped with a cuff 9 with holes for the passage of liquid.

[0019] The mesh size of the upper filter 16 is set with a ratio of at least 3:1 in relation to the mesh size of the lower filter 17. For example, the basic option for the upper filter 16 is 0.3 mm, for the lower filter 17 - 1 mm.

[0020] The cell size of filters 16, 17 is selected depending on the granulometric composition of the removed mechanical impurities, which allows for an increase in the service life due to step-by-step filtration.

[0021] The length of the carrier pipe 11 and the number of disks in the filters 16, 17 are determined based on the condition of their complete placement in the tail pipe 15.

[0022] The proposed filtration system for installing an electric centrifugal pump under conditions of high mechanical impurity content operates as follows.

[0023] When the ESP is operating, produced fluid from reservoir 22 enters liner 15, where it undergoes stepwise filtration, first in the lower filter 17, then in the upper filter 16, which consists of metal mesh discs. The purified fluid then enters the ESP pump sections 4 through inlet module 3 and rises through tubing string 5.

[0024] The filtration system is lowered into the wellbore in the following sequence. First, packer 13 with coupling device 14 and liner 15 are lowered and installed on the production tubing. The production tubing is then disconnected and retrieved. Next, an ESP with a submersible motor 1 is lowered onto the production tubing string 5. A carrier pipe 11 with filters 16, 17 and a centralizer 12 are attached to the base of the sub 10. This centralizer ensures the safe passage of carrier pipe 11 through coupling device 14 and packer 13, as well as the centering of filters 16, 17 within the liner pipe 15. Since their outer diameter is smaller than the inner diameter of production string 21, the mesh disks of filters 16, 17 are not damaged during lowering, unlike their closest analogue.

[0025] Thus, the filtration system increases the reliability of the ESP during oil production under conditions of high content of mechanical impurities by improving the design of the filtration system, which ensures more efficient and long-term purification from mechanical impurities.

Claims

A filtration system for installing an electric centrifugal pump, including a carrier pipe, in the lower part equipped with a centralizer, and in the upper part secured through a sub to the base of the submersible electric motor of the electric centrifugal pump installation, characterized in that it is additionally equipped with a mechanical packer, previously lowered and secured to the production string, on which a docking device and a shank made of tubing are installed, the carrier pipe is equipped with two filters installed in series, each of which is fixed by means of upper and lower metal disks and clamps with screws, the filters are made in the form of truncated cones from disks of a metal mesh made of stainless wire, and the larger base of the cone of each filter is oriented towards the wellhead, coincides with the internal diameter of the shank pipe and is equipped with a cuff with holes for the passage of liquid,in this case, the size of the mesh cells of the upper filter is set with a ratio of at least 3:1 in relation to the size of the mesh cells of the lower filter, the length of the carrier pipe and the number of disks in the filters are determined based on the condition of their complete placement in the tail pipe.

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