RU2470144C1 - Plant for simultaneous-separate extraction of hydrocarbons - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to extraction of hydrocarbons and may be used in separate oil extraction from both one bed and several isolated beds using one well. Proposed plant comprises packer, two pumps for every productive bed arranged on string, packer arranged between top and bottom pumps, and electric cable. In compliance with this invention both centrifugal pumps are engaged with one downhole motor. Motor is fitted on shaft shared by said pumps. Said shaft passes through packer. Motor is coaxially coupled with centrifugal pumps via said shaft. Top pump inlet module is located above packer. Pumps are equipped with units of remote-control system geophysical transducers connected via data transfer lines with remote control system receiver. Pump inlet modules are equipped with oil flow rate controllers with controlled flow section arranged coaxially with shaft rotational axis and coupled with service drives.

EFFECT: higher efficiency, simplified design, control operating conditions of pumps.

5 cl, 1 dwg

Description

The installation relates to hydrocarbon production techniques and can be used in oil production from one reservoir, as well as in simultaneous and separate oil production from several reservoirs isolated from each other using one well, with the exception of hydrocarbon flows from one reservoir to another.

A device is known for simultaneously separately operating several layers using one transit well (see RU 68584 U1, IPC E21B 43/00, published on November 27, 2007). This device contains a packer for separating two layers, two pumps installed each on its own string of tubing (hereinafter tubing), placed in the same well coaxially to each other. One pump - an electric centrifugal pump - is located below the packer for pumping oil from the lower reservoir; for this, a channel for an electric cable is provided in the packer. Above the packer there is a receiving valve for a sucker rod pump with a pump for pumping oil from the upper layer. The electric centrifugal pump operates the lower layer, lifting liquid to the surface, for which channels are provided that allow it to flow around the intake valve in the annular space between the two tubing. From the upper layer, the sucker-rod pump through the side windows of the receiving channel lifts the produced fluid from the upper layer through its tubing string. This setting is selected as the closest equivalent.

The disadvantage of this device is the use of a sucker rod pump with low productivity and the inability to use two electric centrifugal pumps in one tubing string of a standard diameter due to their large dimensions. In addition, the use of two pumps lowered into the well on its tubing string, complicates their operation and maintenance with dismantling, requires a valve to separate the fluid flows from the two layers, which reduces the already low productivity of the upper sucker rod pump.

Another disadvantage of the known device is the inability to monitor the operation of one reservoir in real time (on-line), as well as at the same time separate production of each of the layers, the lack of separate accounting of the produced fluid and the ability to control the pump operation mode for each of the developed reservoirs. If the amount of produced fluid does not match the forecast, or the production of fluid decreases, or the pump starts to operate in critical mode, this can lead to disruption of the pump and / or overheating of the submersible motor due to a decrease in the amount of fluid washing it. Therefore, control and the ability to regulate the operation of the installation are necessary.

The objective is to increase the productivity of the installation with the same dimensions of the tubing string used, simplify the design of the installation, its operation and maintenance, provide the possibility of separate metering of the produced fluid and the ability to control the pump operating mode for the developed formation.

The problem is solved by the design of a hydrocarbon production unit, including:

- electric centrifugal pump mounted on the tubing string,

- an electric cable of an electric centrifugal pump installed in a cable channel running along the tubing string.

The difference between the installation design and the prototype is the following:

- the pump in its lower part is equipped with an input module with a filter or dispersant, or a gas separator,

- the input module of the pump is located near the zones of oil inflow from the reservoir into the well cavity,

- the installation is equipped with a block of geophysical sensors (measuring pressure, temperature, etc.) of the telemetry system,

- the installation is equipped with a flow meter-debitometer,

- a block of geophysical sensors and a flow meter are installed at the input module or in the cavity of the upper pump module, at its output,

- the input module of the pump is equipped with an oil flow regulator made with an adjustable flow area mounted coaxially to the axis of rotation of the pump shaft and connected to the servo drive,

- a block of geophysical sensors and a flow meter are connected by a data transmission line to a receiving block of a telemetry system mounted on a day surface.

The problem is also solved by the second version of the installation design - for simultaneous and separate hydrocarbon production, including:

- a packer hermetically separating the two productive formations of the well,

- the packer is mounted on the casing,

- two pumps for each of the reservoirs installed on the tubing string,

- the packer is installed between the lower and upper pumps,

- an electric cable is installed in the cable channel passing in the packer body along the tubing string.

The difference between the second version of the installation design from the prototype is the following:

- both pumps are electric centrifugal and connected to one submersible electric motor,

- the submersible motor is located under the packer, in the lower part of the installation directly at the lower layer, and mounted on the shaft, common to both pumps, or the motor is mounted on the shaft and located between the centrifugal pumps,

- the shaft passes through the packer, in which additional bearing bearings are installed,

- the electric motor is coaxially connected to centrifugal pumps through a shaft with bearings,

- the pumps in their lower part each are equipped with an input module with a filter or dispersant, or a gas separator,

- the input modules of the pumps are located near the zones of oil inflow from the reservoir into the well cavity,

- the input module of the upper pump is located above the packer,

- the installation is equipped with blocks of geophysical sensors (measuring pressure, temperature, etc.) of the telemetry system and flow meters,

- which are installed at the input modules or at the outlet of the pumps,

- the input modules of the pumps are equipped with oil flow regulators, made with adjustable flow cross-section, mounted coaxially to the axis of rotation of the motor shaft (pump) and connected to the servos,

- blocks of geophysical sensors and flow meters are connected by a data line with the receiving unit of the telemetry system mounted on the day surface.

The problem is also solved by the design of the oil flow regulator, which is made in the form of two coaxially arranged cylindrical surfaces, mounted relative to each other without a gap within the manufacturing tolerance, closely. At least one of them is made with longitudinal holes oriented along the axis, in the form of a cylindrical lattice or with other holes. One of the surfaces is fixed, and the other with the possibility of movement (sliding) relative to the other, and the surface is moved either along their common axis, or translationally along the arc of a circle of its base, with the possibility of overlapping holes.

Other design options for the flow controller are also possible. The design of different versions of the oil flow controller when the movable part is sliding along the axis or in an arc relative to the fixed part provides a change in the area of the passage section of the oil flow controller. The oil flow controller can also be made in the form of a speed controller for the shaft of electric centrifugal pumps using a frequency converter unit in the power circuit of a submersible electric motor.

As can be seen from the essence of the invention, the proposed installation options can be used for oil production from one formation or for simultaneous and separate oil production from several layers separated by packer equipment, with the possibility of adjusting the oil flow.

The drawing shows a variant of the installation for simultaneous-separate oil production from two reservoirs, separated by a packer, equipped with a submersible electric motor, located under the lower electric centrifugal pump. The arrows indicate the movement of oil.

The entire installation is mounted and lowered into the well on one string of tubing.

The installation is located in the casing 1 of the well for simultaneous and separate oil production from two formations: the upper 2 and lower 3. The casing 1 of the well at the occurrence of oil formations 2 and 3 is perforated, as can be seen from the drawing. Under the upper layer 2, a packer 4 is placed, hermetically separating the two productive layers 2 and 3 of the well. The packer 4 is secured to the casing 1 using a packer rubber assembly (not shown). Directly at the lower layer 3, under the packer 4 there is a submersible motor 5 mounted on the shaft 6. The electric motor 5 is kinematically coaxially connected to the lower centrifugal pump 7 through the shaft 6. The pump 7 in its lower part is equipped with an input module 8 with a hydroprotection unit and a filter and with the regulator 9 of the oil flow, made with an adjustable bore in the form of a cylindrical grating. The shaft 6 passes through the packer 4 and further up to the input module 10 of the upper pump 11. The input module 10 of the upper pump is also equipped with a hydraulic protection unit and a filter and is made with an oil flow regulator 12. Input modules 8 and 10 of pumps 7 and 11, respectively, are located in zones of oil leakage from formations 2 and 3 into the casing cavity 1. Bearings are mounted in the packer barrel 4 for transmitting rotation from the shaft 6 to the rotor of the upper pump 11 (not shown). The lower pump 7 has a lower capacity, the upper pump 11 has a higher capacity. The productivity of the lower pump 7 is designed for the potential flow rate of the lower reservoir 3, the calculation of the upper pump 11 takes into account the total flow rate of the lower 3 and upper 2 layers. In the cavities of the upper output modules 13 and 14 of the lower 7 and upper 11 pumps, respectively, the lower and upper flow meters-debitometers (not shown) are installed. The lower flow meter of module 13 is designed to measure the production rate of oil from the lower layer 3, the upper flow meter of module 14 is used to determine the total production rate of oil from the lower 3 and upper 2 layers. The entire installation is mounted and lowered into the well on one column of 15 tubing. On the tubing string 15 in special blocks 16 and 17 directly at the developed formations, a set of pressure and temperature sensors of the telemetry system (not shown) are placed. Flow meters and sensors are connected by a wire line to the telemetry system receiver mounted on the day surface using a data cable 18, through which the signals of the telemetry system are transmitted. An electric cable 19 along the tubing string 15 is lowered to the submersible motor 5 and connected to it, for which a cable channel is provided in the packer element of the packer 4. The over-packer cavity 20 of the casing string 1 is located below the upper reservoir 2 and serves to collect oil from the upper reservoir 2. Both pumps, as shown in the drawing, are interconnected not only by the shaft, but also by a passage pipe 21, through which oil from the lower reservoir 3 with the help of the second pump 11 is supplied together with oil from the upper reservoir 2 to the surface.

As can be seen from the drawing, the packer 4 separates the two productive formations 2 and 3 and is placed between two pumps 7 and 11, pumping oil from the separated formations. Pumps 7 and 11 and a submersible motor 5 are mounted on one shaft 6 using bearings. Shaft 6 is one common drive for them and comes into rotation from one electric motor, powered by one electric cable 19. The entire installation is assembled on the surface.

The oil flow regulators in the input modules 8 and 10 of the pumps 7 and 11, respectively, each are made in the form of two coaxially arranged cylindrical surfaces, mounted relative to each other without a gap within the manufacturing tolerance, closely. The outer cylindrical surface is made with longitudinal holes oriented along the axis in the form of a cylindrical lattice. One of the surfaces is fixed, and the other with the possibility of movement (sliding) relative to the first, and the movement of the surfaces one relative to the second is carried out translationally along the arc of a circle of its base, with the possibility of overlapping holes. The reciprocating motion along an arc of a circle makes a movable cylindrical surface using an electric drive controlled by a telemetric system (not shown).

The following were used as electric centrifugal pumps: lower - three-section ЭЦНД-80-729, upper - three-section ЭЦНД-200. As a submersible electric motor - PED-110 kW. As sensors were used sensors type TMS and TMSR (with flow meters).

Installation works as follows.

A mechanical packer 4 is lowered into the casing 1 of the well, which is transit for the upper formation 2 and the lower formation 3 and made at the location of the formation perforated, on the tubing string 15 and placed on a common reinforced shaft 6 on bearings on both sides of the packer 4 height lower 7 and upper 11 electric centrifugal pumps. A submersible electric motor 5 is installed on the lower end of the shaft 6. The installation is placed so that the electric motor 5 is located above the perforation zone of the casing string 1 from the lower layer 3, and the fluid flow is washed and cooled the motor. Along with the installation, the electric cable 19, already installed in the cable channel, connected to the submersible motor 5 is lowered into the well. The packer 4 is fixed on the inner surface of the casing 1, hermetically disconnecting the layers 2 and 3. The electric cable 19 is connected to the corresponding network, and the cable 18 data transmission - to the control system of the telemetry system (not shown in the drawing), operating in automatic or semi-automatic mode. The submersible motor 5 is turned on, and the rotor of the engine through the bearings begins to transmit rotation to a single shaft 6 and then to the lower 7 and upper 11 centrifugal pumps. Pumps begin to draw fluid from the reservoirs 3 and 2, pumping it upward along the tubing string 15. The flowmeters of the upper modules 13 and 14 of the lower 7 and upper 11 pumps respectively measure the amount of oil passed through the installation from the lower layer 3 and the total of both layers. At the same time, the condition of the wells is monitored using sensors 16 and 17 of the telemetry system, the readings of which, converted into electrical signals, are transmitted upward through the data cable 18 to the control system. There, simultaneously, the readings of the flow meters 13 and 14 are also transmitted in the form of electrical signals. Such data transmission in the process of oil production allows to obtain on-line information on the condition of wells and the amount of oil produced. By changing these conditions, it is possible to regulate the operation of the installation. So, with a decrease in the flow rate of the lower layer and at the originally installed oil supply power due to the set rotation speed of the electric motor / shaft 6, the submersible electric motor 5 may be in conditions of insufficient amount of fluid washing and cooling it, it will end up in a critical mode of operation, which will lead to burnout and / or disruption of oil supply. The sensors of the telemetry system will monitor such a change in operating conditions, and to eliminate the consequences of a critical operating mode, the telemetry system control system will automatically or manually send a signal to the appropriate servos to increase the flow area of the oil flow regulator in the input unit of the corresponding pump, which will normalize the pump operating conditions . You can also change the engine speed to change the volume of oil from the reservoir.

Claims (5)

1. Installation for simultaneous and separate hydrocarbon production, including a packer, two pumps for each of the reservoirs installed on the tubing string, a packer installed between the lower and upper pumps, an electric cable, characterized in that both pumps are centrifugal and connected to one submersible electric motor, the electric motor is mounted on the shaft, common to both pumps, the shaft passes through the packer, the motor is coaxially connected to the centrifugal pumps through the shaft, the input module of the upper pump is located above the pack Pumps are equipped with blocks of geophysical sensors of the telemetric system and flow meters connected by a data line to the receiving block of the telemetric system, the input modules of the pumps are equipped with oil flow regulators made with adjustable flow cross-section, mounted coaxially with the axis of rotation of the shaft and connected to servos. 2. Installation according to claim 1, characterized in that the packer has additional bearing bearings. 3. Installation according to claim 1, characterized in that the block of geophysical sensors is installed at the input module of the pump. 4. Installation according to claim 1, characterized in that the flowmeter is installed in the cavity of the output module of the pump. 5. Installation according to claim 1, characterized in that the output module of the lower pump is located above the packer and is equipped with output channels.

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