RU2405918C1 - Method of garipov for oil production and device for its realisation - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: method for oil production includes dispersion of reservoir fluid with gas and subsequent supply of gas-liquid mixture to intake of electric centrifugal pump. According to invention, upper reservoirs and lower reservoirs and/or interval of well leakiness are isolated by installation of at least one packer over electric centrifugal pump. Gas is separated with simultaneous ejection of gas from below-packer zone into lifting pipes over electric centrifugal pump. Dispersion of reservoir fluid is done with reservoir and below-packet gas, and it is executed in below-packer zone until uniform homogenous gas-liquid mixture is produced, with its further supply to intake of electric centrifugal pump and pumping of uniform homogenous gas-liquid mixture to surface.

EFFECT: increased efficiency of well operation.

11 cl, 9 dwg

Description

The invention is intended for the oil industry and can be used in oil production from wells with high and low gas content, as well as with simultaneous separate and alternate operation of several layers of the well.

A known method of oil production, including pumping products from the reservoir, partial separation of gas from the liquid, ejecting part of the production of the well, dispersing the gas-liquid mixture and its subsequent flow into the pump (RF Patent No. 2274731, E21B 43/00, F04F 5/54, publ. 20.04 .2006).

This method has limited use. It cannot be used for simultaneous and separate exploitation of several layers or objects of development, as well as in the case where a leak interval is located above the developed layer, which strongly absorbs or gives away the object. In addition, the combined use of a centrifugal electric pump (hereinafter referred to as ESP) and a jet pump to increase oil production from a single facility has not been widely used due to the need to use ESP with higher heads (300-500 m higher than nominal) to overcome high resistances arising in the area of narrowing in the nozzle of the ejector jet pump. It should be borne in mind that the higher the pump creates a pressure head, the lower its performance will be. In this method of oil production, the cost of electricity for raising a unit of output is significantly increased. In addition, this leads to a decrease in efficiency and a decrease in the overhaul period of the ESP.

This method has a very low efficiency in wells with a high saturation pressure of the products they produce and, accordingly, a high level of fluid in the annulus.

During the operation of the pump, it is impossible to reduce the pressure at the pump inlet by 10-20% below the saturation pressure, respectively, the liquid level and the depth of installation of the ejector due to the significant release of dissolved gas from the reservoir fluid, leading to a disruption in the pump supply.

A device for oil production is known containing a pump, a jet device and a gas separator-disperser launched into a well on a tubing string (RF Patent No. 2274731, E21B 43/00, F04F 5/54, publ. 04/20/2006).

The above device cannot be used for simultaneous separate and sequential operation of several layers, as well as if a leak interval is located above the developed layer, which strongly absorbs or displays the object.

The disadvantage of this device is that it is limited to use in wells in which there is no possibility of gas accumulation in the annulus. This is especially true for wells with cable entry, crimping of which at 40-60 atm determines the restriction in gas accumulation by pressure in the annulus .

In addition, the use of check valves in the well reinforcement complicates the design and completely eliminates the excess of pressure in the annulus above the collector, which makes it inefficient to use a jet pump for pumping annulus gas for lifting and bubbling liquid gas above the pump. The presence of a high level of fluid in the annulus leads to inefficient operation of the device due to the fact that the jet pump in the annulus is washed by the annulus and not gas.

Closest to the proposed technical solution is a method of producing formation fluid from a well, comprising dispersing the formation fluid with gas, followed by feeding it to an electric centrifugal pump (RF Patent No. 2224877, E21B 43/00, publ. September 20, 2003, prototype).

This method is limited in application, as it is intended only for wells with low gas content and for the development of one reservoir. Moreover, the method does not allow simultaneous separate and sequential operation of several formations and does not imply cutting off from upstream waterlogged intervals or aquifers, leakage zones and absorbing objects that adversely affect well operation.

Closest to the proposed technical solution is the "Installation of a submersible electric centrifugal pump for producing formation fluid from the well" containing tubing, ESP and dispersant (RF Patent No. 2224877, E21B 43/00, publ. September 20, 2003, prototype).

The disadvantage of the prototype is the low efficiency of the installation for pumping fluids, especially when their gas content is high, when the gas volume exceeds 100% of the volume of the reservoir fluid. The installation cannot be used for simultaneous separate and sequential operation of several layers, as well as in the case of a leakage interval with significant water development or a highly absorbing object above the developed layer.

The proposed technical solution avoids the drawbacks mentioned above, increase the well’s operating efficiency, increase the productivity and operating efficiency of the installation by dispersing gas in the liquid from the sub-packer zone and eliminating its harmful effect on the ESP operation, as well as eliminating the negative effect of the upper leakage intervals and absorbing objects for well operation.

This goal is achieved by the fact that the proposed technical solution - the method of oil production - includes dispersing the reservoir fluid with gas, followed by the supply of a gas-liquid mixture to receive an electric centrifugal pump, cutting off the upper reservoirs and / or the leakage interval of the well by installing at least one packer above electric centrifugal pump, while the dispersion of the reservoir fluid is carried out with reservoir and sub-packer gas and produce it in the sub-packer zone until a homogeneous th a gas-liquid mixture with its subsequent supply to the reception of an electric centrifugal pump and pumping a homogeneous homogeneous gas-liquid mixture to the surface, in addition, gas is ejected from the sub-packer zone, gas is additionally separated while gas is ejected from the sub-packer zone into the tubing above the electric centrifugal pump, and additionally cutting off the layers between themselves by installing at least one packer below the electric centrifugal pump and adjusting Incoming of formation fluid to the reception electrocentrifugal pump via a control device mounted in the bearing element of the packer or tubing and / or a downhole chamber.

The downhole installation for oil production includes an electric centrifugal pump mounted on a tubing string, a disperser located at the inlet of the electric centrifugal pump, at least one packer mounted above the electric centrifugal pump, the well installation is further provided with a receiving grid, at least one ejector, located between the packer and the electric centrifugal pump or between packers, or at least one gas separator located in front of the dispersant, and at least one ejector, p located between the packer and the electric centrifugal pump or between packers, a multiphase pump, a dispersant or dispersants, the packer being made with a barrel having an axial through channel or a through groove with a gas permeable and / or sealing filler, in which the power cable is sealed, and as a gas permeable and / or sealing filler use silicone glue, compound, epoxy resin, the power cable is additionally equipped with at least one stuffing box sealing element, at least one clamping device with rubber cuffs and rubber gaskets.

In Fig.1 shows a well installation for oil production in the context; figure 2 shows a downhole installation for oil production using two packers and an ejector, figure 3 shows a downhole installation for oil production using a gas separator and an ejector; figure 4 shows a downhole installation for oil production using a multiphase pump; 5-9 explain the implementation of the proposed method of oil production.

A downhole oil production installation comprises a pipe string (tubing) 1 of constant or variable diameter, an electric centrifugal pump (hereinafter referred to as ESP) 2, at least one packer 3 mounted above the ESP 2, and at least one dispersant 4, located at the entrance-reception of ESP 2.

Dispersant 4 allows you to break large bubbles into tiny bubbles, preventing them from sticking together and combining, to eliminate the formation of gas plugs in the flowing part of ESP 2, blocking its operation, and to mix free gas in a liquid, forming a homogeneous homogeneous gas-liquid mixture.

The use of a dispersed homogeneous gas-liquid mixture before entering ESP 2 reduces the harmful effect of gas on ESP 2, which ensures uninterrupted operation of ESP 2, increasing its productivity and operating efficiency.

The location of at least one packer 3 above the ESP 2 will allow the gas to accumulate in the sub-packer zone and thereby create a pressure in the annulus of more than 60 atm.

Packer 3, located above ESP 2, cuts off the upper layers and wellhead reinforcement from increased gas pressure, which prevents the effect of increased gas pressure on wellhead equipment, including on stuffing box sealing elements (not shown in FIG.) having a pressure limit of 40-60 atm. In addition, the packer 3 installed above the ESP 2 is intended for dividing the annular space into subpacker and overpacker regions, while only the subpacker region is involved in the development of ESP 2.

Packer 3, accumulating free gas in the sub-packer region, provides the possibility of transferring it to the tubing region of the tubing 1 above the ESP 2 for additional bubbling and gas-lifting of the gas-liquid mixture. The location of the packer 3 above the ESP 2 also allows you to cut off during the operation of the well intervals of leaks or intervals of perforation of the upper layers, for example, in view of their strong flooding. This leads to a decrease in water cut and an increase in oil production, which further increases the efficiency of well operation. When using more than one packer 3 above ESP 2, an additional packer is installed above packer 3.

The downhole installation for oil production is additionally equipped with a multiphase pump 5. The multiphase pump 5 is installed at the intake of the ESP 2 to increase its backwater, to ensure an increase in pressure and the intensity of mixing of the multiphase flow entering the ESP 2. In this case, the multiphase pump 5 is installed, for example, under dispersant 4, increases the backwater, provides an increase in pressure and the intensity of mixing of the formation fluid and free gas coming from the formation or from the annular sub-packer space va, inlet 4, and then dispersing in ESP 2.

The downhole installation for oil production is additionally equipped with at least one ejector 6 located between the packer 3 and the ESP 2 or between the packers 3 located above the ESP 2.

The ejector 6 provides free gas bypass from the sub-packer zone to the tubing 1 above the ESP 2 and provides for the lifting and sparging of the liquid (formation fluid) with gas inside the tubing 1. In addition, the ejector 6 provides an additional selection of the formation fluid from the upper formation located above the ESP 2.

The ejector 6 may be, for example, a jet pump.

The downhole oil production unit is additionally equipped with at least one gas separator 7 located in front of the dispersant 4, and at least one ejector 6 located between the packer 3 and ESP 2 or between the packers 3 located above ESP 2.

The gas separator 7 protects the ESP 2 from breakthroughs of free gas, sometimes coming in with the formation fluid in the form of gas packs, and is designed to separate and separate the free and part of the dissolved gas from the liquid (reservoir fluid) entering the ESP 2 and transfer the free gas to annulus.

The downhole installation for oil production is additionally equipped with dispersant 4 or dispersant 4, the use of which will allow for more intensive mixing - dispersion of the formation fluid with gas.

Packer 3 contains a barrel with a through axial channel or with a through groove in which the power cable 8 is tightly connected, connecting the ESP 2 to the control station (not shown in Fig.).

The power cable 8 is placed in a through axial channel or in a through groove filled with a gas permeable and / or sealing filler, or fixed in a through axial channel or in a through groove using clamping devices with rubber cuffs and rubber gaskets or stuffing box packing elements, etc. In addition, the power cable 8 installed in the axial through channel or through groove with gas permeable and / or sealing filler, is additionally equipped with sealing gaskets or rubber cuffs.

The gas permeable and sealing filler is, for example, a compound, silicone glue, epoxy resin, putty and the like, which seals and holds the power cable 8 instead of the cable entry in the axial through channel or through groove.

In addition, the well installation for oil production is additionally equipped with a receiving grid 9, which protects it from clogging with mechanical impurities.

The method of oil production involves installing a pipe string (tubing) 1 into a well at a predetermined depth.

Above ESP 2, the upper layers and / or the interval of the leakage of the well are cut off by installing at least one packer 3 on the tubing 1. During the cutting of the upper layers and / or the interval of leakage of the well by installing at least one packer on the tubing 1 3 a subpacker zone is formed.

Then, in the sub-packer zone, dispersing the formation fluid with the reservoir and sub-packer gas is carried out by means of the dispersant 4 to obtain a homogeneous homogeneous gas-liquid mixture. The obtained homogeneous homogeneous gas-liquid mixture is fed to ESP 2 with further pumping to the surface of a homogeneous homogeneous gas-liquid mixture.

To improve the performance of the pumped products, gas is additionally ejected from the under-packer zone by means of an ejector 6.

The installation of more than one packer 3 over the ESP 2 is also necessary in cases of simultaneous-separate and alternate operation of several layers, for example, one layer is produced by the ejector 6 in the form of a jet pump, and the other layer is produced by the ESP 2 (Figure 2).

To reduce the gas content in the wells, gas is additionally separated by a separator 7 into the annulus and into the under-packer zone, while gas is ejected from the under-packer zone into the tubing 1 above ESP 2 by, for example, a jet pump 6.

The method of oil production provides for additional cutting of the formations between themselves located below the ESP 2 by installing below the ESP 2 at least one packer 10. In this case, the flow of reservoir fluid to the intake of ESP 2 is controlled by means of a control device 11, for example, in the form adjustable fitting or valve installed in the landing element of the packer 10 or tubing 1, and / or in the borehole chamber 12 (Fig.5-9).

The location of the at least one packer 10 under the ESP 2 allows you to cut off one or more underlying layers and conduct simultaneous, separate and sequential production of products from the reservoir and regulate the pumping of products from the reservoir by means of a regulating device 11, for example, in the form of an adjustable fitting or valve.

Additional cutting off of one formation or several layers with at least one packer 10 located below the ESP 2 is also carried out to limit and control the flow of fluid from these layers. The reason for this limitation may be associated, for example, with high water cut, etc.

At the same time, additional regulation of formation fluid withdrawals from the reservoirs below ESP 2 limits the unwanted intake of highly watered formation fluid to receive ESP 2.

Downhole installation for oil production works as follows.

A packer 3 is lowered into the borehole on the tubing string 1, with a hermetically sealed power cable 8, ESP 2 running through a submersible electric motor 13 passed through it. At the inlet of ESP 2 a disperser 4 with a receiving grid 9 is installed.

Packer 3 is installed over ESP 2 at a predetermined depth with the separation of the borehole space into an overpacker and a subpacker zone.

ESP 2 and dispersant 4 are driven by a submersible electric motor 13 after power is supplied via the power cable 8.

After starting a pre-production installation for oil production, formation fluid and gas from the under-packer zone pass through a receiving grid 9 into a dispersant 4. Gas with a liquid (formation fluid) is dispersed by a dispersant 4 to a finely dispersed homogeneous state and enters an ESP 2, which pumps the dispersed product into as a homogeneous homogeneous gas-liquid mixture to the surface. See figure 1.

Dispersant 4 eliminates the formation of gas plugs in the flowing part of ESP 2, blocking its operation, and by reducing the harmful effects of gas, the operation of ESP 2 improves, i.e. increases the productivity and efficiency of the well installation for oil production.

Downhole installation for oil production with two packers 3 located above the ESP 2, and an ejector 6 when used for simultaneous-separate and alternate operation of two layers, the device operates as follows.

A packer 3 is lowered into the well on a tubing string 1 with a power cable 8 passed through it, fixed by clamping devices with rubber cuffs, an ESP 2, at the input of which a dispersant 4 with a receiving net 9 is installed, and an ejector 6 in the form of a jet pump located between the packers 3 .

ESP 2 and dispersant 4 are driven by a submersible electric motor 13 after power is supplied via power cable 8. Gas in the free phase is trapped and accumulated under packer 3.

After starting the submersible electric motor 13, the formation fluid and gas from the sub-packer zone pass through the intake grid 9 into the dispersant 4, where the gas with the formation fluid is mixed to a finely dispersed homogeneous state in the form of a homogeneous homogeneous gas-liquid mixture, then the obtained homogeneous homogeneous gas-liquid mixture is received at the ESP 2, which pumps the resulting homogeneous homogeneous gas-liquid mixture to the surface.

In this case, the ejector 6 makes an additional selection of the formation fluid from the upper reservoir located above the ESP 2. See figure 2.

The use of dispersant 4 and ejector 6 between the packers 3 located above the ESP 2 improves the operation of ESP 2, increases the productivity and efficiency of the proposed installation by reducing the density of a homogeneous homogeneous gas-liquid mixture and backpressure on ESP 2, eliminating the formation of gas plugs in the flow part of ESP 2 blocking its work, and also increases the flow rate due to the additional selection of fluid from the upper reservoir located above the ESP 2.

Downhole installation for oil production with a gas separator 7 and an ejector 6 operates as follows. See FIG. 3.

If the volume of gas in the volume of the reservoir fluid is within 25-100% and above, then the formation fluid is additionally separated with the release of free gas into the sub-packer space simultaneously with ejection.

The packer 3 is lowered into the borehole on the tubing string 1 with a power cable 8 passed through it, fixed with clamping devices with rubber cuffs, ESP 2, at the input of which a receiving grid 9, a gas separator 7, a disperser 4, and an ejector 6 in the form of a jet pump are located between packer 3 and ESP 2.

Submersible motor 13 is launched, which drives the gas separator 7, dispersant 4 and ESP 2.

The formation fluid passes through the intake grid 9, trapping mechanical impurities, and then enters the gas separator 7, which removes excess gas into the annular under-packer space. Next, the reservoir fluid passes through dispersant 4 and enters the ESP 2.

ESP 2 by tubing 1 pumps out dispersed products in the form of a homogeneous homogeneous gas-liquid mixture, which then passes through the ejector 6 and captures free gas from the sub-packer zone, increasing the productivity and efficiency of the proposed installation, including through additional lifting and bubbling of the liquid with gas inside Tubing 1. See figure 3

Gas lifting and bubbling with gas provides a decrease in the density of the reservoir fluid column "over ESP 2 and facilitates the lifting of well products to the surface.

The gas formed in the under-packer zone reduces the pressure at the intake of ESP 2 below the saturation pressure. Reducing the weight of the column of liquid to be raised and reducing the backpressure at ESP 2 increases the performance and efficiency of ESP 2 due to the separation of a part of the gas and passing it into the annulus by the gas separator 7 and due to the bypass of the gas into the tubing 1 by the ejector 6 above the ESP 2.

Downhole installation for oil production with a multiphase pump 5 and a receiving grid 9 operates as follows. See FIG. 4.

A packer 3 is lowered into the well on a tubing string 1 with a power cable 8 passed through it, fixed by clamping devices with rubber cuffs, ESP 2, at the input of which a receiving grid 9, a multiphase pump 5 and a dispersant 4 are installed, and set at a predetermined depth. The submersible motor 13 is launched, which drives the multiphase pump 5, dispersant 4, ESP 2.

The multiphase pump 5 captures the liquid with gas and, strongly mixing them, pumps the gas-liquid mixture under pressure into the dispersant 4. As a result of pumping the gas-liquid mixture, the pressure in the bottom-hole zone of the formation decreases and the gas-liquid mixture begins to flow to the well oil production unit. The multiphase pump 5 due to forcing and increasing the back pressure at the reception of ESP 2 significantly improves the pump operation parameters.

In the dispersant 4, the gas with the liquid is dispersed to a finely dispersed homogeneous state and is fed to the ESP 2, then ESP 2 is pumped out in the form of a homogeneous homogeneous gas-liquid mixture to the surface.

The method of oil production is as follows. See FIG. 5.

A tubing 1 is lowered into the well with a packer 10 and a column disconnector 14, a downhole chamber 12 with a regulating device 11 in the form of a deep adjustable fitting. The packer 10 is installed at a predetermined depth below the ESP 2 between the layers.

Then, the tubing 1 with the packer 3, the ESP 2 with the power cable 8, the dispersant 4 and the receiving grid 9 are lowered and set to a predetermined depth. The packer 3 divides the borehole space into the above-packer and sub-packer zones, thereby cutting off the upper layers and / or leak intervals located above ESP 2.

At the same time, the power cable 8 is sealed in the trunk of the packer 3.

The packer 10, installed below ECR 2, cuts off the formations located below ESP 2. The flow of reservoir fluid to the reception of dispersant 4 and ESP 2 through the receiving grid 9 is controlled by a deep adjustable fitting 11 installed in the planting element of the borehole chamber 12.

The submersible electric motor 13 is activated, which drives the ESP 2 and the dispersant 4.

In the sub-packer zone, dispersant 4 disperses the formation fluid with the reservoir and sub-packer gas to obtain a homogeneous homogeneous gas-liquid mixture, which is fed to the ESP 2, with further pumping in the form of a homogeneous homogeneous gas-liquid mixture to the surface.

The application of the method of oil production and installation for its implementation can improve the efficiency of the well, increase productivity and operational efficiency of the installation by reducing the harmful effects of gas on the ESP and lowering the density of the column of well fluid over the ESP.

The use of additional equipment, namely, the use of more than one packer, allows to increase the flow rate of the well by selecting reservoir fluid from the second, etc. formation, the use of a separator and an ejector ensures the lifting and bubbling of the well product when it is raised to the surface due to the use of free gas energy raising the sparged fluid, as well as by reducing backpressure on the ESP and reducing gas pressure on the wellhead equipment, thereby increasing operating efficiency wells.

The uninterrupted operation of the ESP ensures, ultimately, the effective operation of the well. In addition, the use of packers and control devices located under the ESP allows for additional simultaneous, separate and alternate operation of several layers located under the ESP.

Claims (11)

1. A method of oil production, comprising dispersing the formation fluid with gas, followed by supplying a gas-liquid mixture to receive an electric centrifugal pump, characterized in that the upper layers and lower layers and / or the leakage interval of the well are cut off by installing at least one packer above the electric centrifugal pump pump, gas is separated with simultaneous ejection of gas from the sub-packer zone to the tubing - tubing above the electric centrifugal pump, and the dispersion is a fluid reservoir and carried out with the gas and produce packer in its area below the packer to obtain a uniform homogeneous liquid mixture, followed by feeding it to the reception electrocentrifugal pump and pumping at the surface of a uniform homogeneous liquid mixture. 2. The method of oil production according to claim 1, characterized in that they additionally cut off the layers between themselves by installing at least one packer below the electric centrifugal pump and regulating the flow of formation fluid to the intake of the electric centrifugal pump by means of a regulating device installed in the packer landing element or tubing and / or in the borehole chamber. 3. A downhole installation for oil production, including an electric centrifugal pump installed on a tubing string — tubing — an ESP and a dispersant located at its inlet, characterized in that it is additionally equipped with at least one packer installed above the ESP at least one ejector located between the packer and the electric centrifugal pump or between packers located above the ESP, and at least one gas separator located in front of the dispersant. 4. The downhole installation for oil production according to claim 3, characterized in that it is additionally equipped with a receiving grid. 5. Downhole installation for oil production according to claim 3, characterized in that it is additionally equipped with a multiphase pump. 6. Downhole installation for oil production according to claim 3, characterized in that it is equipped with an additional dispersant or dispersants. 7. The downhole installation for oil production according to claim 3, characterized in that the packer is made with a barrel having an axial through channel or a through groove with a gas permeable and / or sealing filler, in which the power cable is hermetically fixed. 8. The downhole installation for oil production according to claim 7, characterized in that silicone glue or compound is used as a gas-permeable and / or sealing filler. 9. The downhole installation for oil production according to claim 7, characterized in that an epoxy resin is used as a gas-permeable and / or sealing filler. 10. The downhole installation for oil production according to claim 7, characterized in that the power cable is additionally equipped with at least one stuffing box sealing element. 11. The downhole installation for oil production according to claim 7, characterized in that the power cable is additionally equipped with at least one clamping device with rubber cuffs and rubber-metal gaskets.

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