RU165961U1 - INSTALLATION FOR SEPARATE OIL AND WATER PRODUCTION FROM A HIGHLY WATERED OIL WELL - Google Patents

Abstract

The proposed utility model relates to the oil industry and can be used for the operation of highly watered oil wells as donor (intake) wells during cross-hole pumping of water in order to maintain reservoir pressure, as well as water wells in the production of which contain associated oil.

The essence of the utility model:

In an installation for separate production of oil and water from a highly watered oil well, including a tubing string with an electric centrifugal pump in a sealing casing, lowered into the production casing of the well and wellhead fittings connected to the water line, an input device consisting of a liner plugged from the lower end divided into sections with inlet openings in a row and cups that perform the function of admitting divided water into the inlet device, the annulus above the sealant casing for the accumulation of separated oil. To lift the separated oil from the annulus of the borehole to the surface, the tubing string is made of a larger diameter and the tubing string of smaller diameter is concentrically placed in it with a tubular sucker pump operating from the pumping unit drive, the upper part of the tubing string pipes of smaller diameter in the wellhead fittings are connected to the gland device of the oil line, and the lower part is sealed to the switch using a rod pump in the tubing string of a larger diameter at a depth below the dynamic level of the fluid in the well, which provides separate cross-flow of fluid flows, the switch is equipped with peripheral vertical channels for an upward flow of water, a cylindrical chamber for lip mounting of the rod pump cylinder and side channels hydraulically communicating the cylindrical chamber with the annulus of the well.

The installation increases the reliability of production of the accumulated separated oil and ensures that when the formation is absorbed (at low reservoir pressure), it rises to the surface of the oil from the annulus without interrupting the operation of the electric submersible pump, which eliminates a simple well. Also, the use of the installation allows economically feasible use in highly watered oil wells according to the degree of water cut of 97% -99% as donor wells (water wells), taking into account their territorial and rational location in the field, where it is necessary to maintain reservoir pressure by cross-pumping water, which will significantly reduce the length of water lines to injection wells. 4 ill.

Description

The proposed utility model relates to the oil industry and can be used for the operation of highly watered oil wells as donor wells (water wells) during cross-hole pumping of water in order to maintain reservoir pressure, as well as water wells that contain associated oil.

The well-known "Installation for the operation of the well" (patent RU №2335625, ЕВВ 43/14, publ. Bull. №28 from 10.10.208 g), designed to pump part of the produced water from the reservoir through the flow line into the injection wells, and the other part water - into the overlying oil reservoir. The installation comprises a packer between the layers, a column of tubing with radial holes for communication with the annulus, an electric centrifugal pump equipped with an external sealing casing, the receiving part of which communicates with the under-packer formation, and the injection part with the cavity of the tubing string.

The disadvantage of the installation is that when it is used for the operation of water wells with oil-containing products or highly flooded oil wells as donor wells, oil can enter the injection wells and the receiving reservoir, since the installation does not provide for the separation of water and oil.

The closest in essence and the achieved result is "Installation for downhole separation of oil from water" (Patent RU No. 2531976, ЕВВ 43/38, publ. 10/27/2014), including a tubing string with an electric centrifugal pump and a flush-return a valve lowered into the production casing of the well. The electric centrifugal pump is equipped with an external sealing casing, made with the possibility of hydraulic communication receiving the electric centrifugal pump with an input device consisting of a shank plugged from the lower end, divided into sections with inlet openings. At the level of each inlet, the shank is equipped with a glass that performs the functions of the inlet of divided water into the inlet device and a water trap for oil drops. In this case, the inlet openings are arranged in one row along the liner and are made with a decreasing diameter in each subsequent section in an upward direction, and the gap between the casing and the production casing of the well serves as a passage channel for oil droplets.

The known device has the following disadvantages:

- to raise the accumulated oil to the surface, an additional pumping unit and backup water are required for flushing through the flushing and non-return valve;

- at low reservoir pressures, the device does not allow to raise the accumulated oil from the annulus to the surface due to the presence of reservoir absorption. In addition, to flush the accumulated oil from the annulus, it is necessary to stop the operation of the electric submersible pump, which leads to a downtime of the well;

- low reliability of the flushing and non-return valve due to the presence of solids and salts in the produced products of the well.

The proposed utility model solves the problem of improving the reliability of downhole equipment with the provision of lifting the accumulated oil to the wellhead at low reservoir pressure without stopping the operation of the well.

The problem is solved in that in the installation for the separate production of oil and water from a highly watered oil well, including a tubing string with an electric centrifugal pump in a sealing casing, lowered into the production string of the well, and wellhead fittings connected to the water line, an input device, consisting of a shank plugged from the lower end, divided into sections with inlet openings in one row and glasses, which perform the functions of inlet of divided water into the input device, annular space above the sealing casing for the accumulation of separated oil, according to a utility model, the tubing string is made of a larger diameter and the tubing string of smaller diameter is concentrically placed in it with a tubular sucker pump operating from the pumping unit drive, the upper part of the tubing string -compressor pipes of smaller diameter in the wellhead fittings are connected to the gland device of the oil line, and the lower part is sealed with a rod pump Nene with a switch installed in a column of tubing of larger diameter at a depth below the dynamic level of the fluid in the well, which provides separate cross-flow of fluid flows, while the switch is equipped with peripheral vertical channels for the passage of the upward flow of water, a cylindrical chamber for cuff mounting the rod cylinder pump and side channels hydraulically communicating the cylindrical chamber with the annulus of the well.

In FIG. 1 schematically shows the claimed installation; in FIG. 2 - lower part of the input device; in FIG. 3 - switch in longitudinal section with a cylindrical chamber; in FIG. 4 is a transverse section aa.

Installation for the operation of the well, contains a suspension of the tubing string (tubing) of large diameter 1 with an electric centrifugal pump 2, which are lowered into the production string of the well 3. Submersible motor (PEM) 4 and the receiving part (input module) 5 of the electric centrifugal pump 2 with an external the sides of the annulus 6 and the separation chamber 7 are sealed with a casing 8. In the tubing string of a larger diameter 1, a tubing string of a smaller diameter 9 is concentrically placed with a tubular rod pump 10 operating from the drive SK (in Fig. Not shown). The upper part of the tubing string 9 in the wellhead fittings of the AUDK 50 × 14 type (used in the two-layer MEM) is connected to the gland device of the oil line 11, and the lower part is sealed with a rod pump 10 to the switch 12 installed in the tubing string of a larger diameter 1 on depth below the dynamic fluid level in the well. The switch 12, providing separate cross-flow of fluid flows, is equipped with a cylindrical chamber 13 for cuffing (from plug-in pumps) of the cylinder of the tube pump 10, side channels 14, hydraulically communicating the cylindrical chamber with the annular space 6 and vertical peripheral channels 15 for the passage of pumped water by an electric centrifugal pump 2. A shank 16 of the input device located in the separation chamber 7 formed from the annular space is connected to the nozzle of the casing 8 Turning 3 between the production tubing and the casing of the input device. The gap between the casing 8 and production casing 3 provides the inlet of oil droplets, and their accumulation in the upper part of the annular space 6. The shank 16 is muffled with the lower end and is provided along the entire length along the housing with one row of inlet openings 17 and cups 18 that perform the function of a water seal for oil drops . The input device consists of several sections with a decreasing diameter of the inlet openings 17 in each subsequent section in an upward direction. In the wellhead reinforcement of the well, the tubing string of large diameter 1 is tied up with a water supply 19. The suspension of the rod string 20 of the pump 10 at the wellhead is connected by the head of the rocker of the rocking machine (not shown).

The geometric dimensions of the inlet device for the proposed installation are selected based on the expected flow rate or performance of the electric centrifugal pump 2. The length of the inlet device is selected based on the number and diameter of the inlet openings 17 to ensure a portioned distribution of the produced fluid stream in such a way that the speed of the downward flow of water in each portion entering in the glass 18 of the input device, less than the rate of ascent of droplets of oil in water. The length of the shank 16, the number and diameter of the inlet holes 17 in each section is selected in accordance with the prototype.

Installation for separate production of oil and water from a high-water oil well works as follows.

The operating experience of donor wells with a device for downhole separation of oil from water shows that the most favorable conditions for the gravitational principle of separation of oil from water are in the interval from the top of the formation to the pump. In this interval, due to the laminar regime of fluid movement in the production string, oil droplets emerging from the perforation holes move in separate droplets or, merging (due to the different speed of the oil droplets in the stream) form large drops of oil. In addition, if there is even slight curvature in the well in this interval, oil droplets merge and move along the upper generatrix of the inner surface of the production string, and depending on the amount of oil in the produced water, it can either be in the form of large drops or a thin stream of oil.

During operation of the electric centrifugal pump 2, an upward flow of water with oil droplets coming from the formation in the annular space of the separation chamber 7 formed between the liner 16 and production casing 3 moves along the inlet device and redistributes along the inlet openings 17. The upward fluid flow in the separation chamber 7 on the path between the glasses 18 sharply reduces the speed due to the large cross-sectional area of the annular space, creating conditions for gravitational separation of water from the total current. Moreover, each divided portion of the downward flow of water without trapping oil droplets from the upper open part of the glass 18 and then through the inlet openings 17 enters the shank 16. The speed of each individual portion of the downward flow is less than the rate of ascent of the oil droplets in the water, and the speed of the main (ascending) stream moving further along the glass 18 is quite high and ensures the removal of oil drops, bypassing the glass 18. This is further facilitated by the coincidence of the direction vectors of the ascent of the oil drops and the product zhayuschayasya portion ascending fluid stream. In this case, the speed of the upward flow as it rises along the inlet device gradually decreases due to portioned water withdrawal in the previous openings, and inside the shank due to the alternate water intake, it gradually increases, therefore, the diameter of the inlet openings 17 of the upper last section of the inlet device is correspondingly smaller than lower sections. This allows you to have the speed of the downward flow of water entering the glasses 18 on the upper section of the inlet device, also less than the rate of ascent of oil droplets in the water, which ensures their further ascent upward. The produced water purified from oil passes through the liner 16 to the intake 5 of the electric centrifugal pump 2, and the oil rises through the gap between the casing 8 and the production casing 3 and then accumulates in the annular space 6 of the well.

During the operation of the installation, the produced water through the tubing string 1 rises to the surface and in the wellhead fittings along the flow and water supply lines 19 is pumped into injection wells. At the same time, the process of oil accumulation in the annulus 6 of the well takes place. During the stop of the sucker rod pump 10, which is the initial stage of the well’s operation, due to the flow and accumulation of oil in the annulus 6, the oil-water section eventually falls below the switch 12. After filling the annulus 6 with a sufficient amount of oil, the sucker rod pump 10 is put into operation. At the same time, oil from the annulus 6 through the lateral openings 14 of the switch 12 is received by the sucker rod pump 10 and then pumped through the tubing string 9 to the oil pipeline 11. The filling time of the annular space 6 with oil is calculated based on the flow rate and water cut of the produced fluid, or determined experimentally .

The operation of the sucker rod pump, depending on the amount of oil in the produced water, can be in a constant or periodic mode, established experimentally, sequentially taking a fluid sample from the oil line.

The installation increases the reliability of production of the accumulated separated oil and ensures that when the formation is absorbed (at low reservoir pressure), it rises to the surface of the oil from the annulus without interrupting the operation of the electric submersible pump, which eliminates a simple well. Also, the use of the installation allows economically feasible use in highly watered oil wells according to the degree of water cut of 97% -99% as donor wells (water wells), taking into account their territorial and rational location in the field, where it is necessary to maintain reservoir pressure by cross-pumping water, which will significantly reduce the length of water lines to injection wells.

Claims (1)

Installation for separate production of oil and water from a high water well oil well, including a tubing string with an electric centrifugal pump in a sealing casing, lowered into the production string of the well, wellhead fittings connected to the water line, an input device consisting of a liner plugged from the lower end, divided into sections with inlets in one row and cups that perform the functions of inlet of divided water into the inlet device, the annulus above the seal them a casing for the accumulation of separated oil, characterized in that the tubing string is made of a larger diameter and concentrically placed a tubing string of smaller diameter with a tubular suction pump operating from the pumping unit drive, the upper part of the tubing string pipes of smaller diameter in the wellhead fittings are connected to the gland device of the oil line, and the lower part is sealed by means of a rod pump to the switch installed in the column tubing of larger diameter at a depth below the dynamic level of the liquid in the well, which provides separate cross-flow of fluid flows, the switch is equipped with peripheral vertical channels for the passage of the upward flow of water, a cylindrical chamber for cuff mounting the cylinder of the sucker rod pump and side channels hydraulically communicating cylindrical chamber with annulus of the well.

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