RU2672365C1 - Method for developing oil deposit on unsteady cyclic pumping mode and device for its implementation - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: invention relates to the oil industry and can be used in the development of oil deposits on a transient cyclical injection mode. Method of developing an oil reservoir in an unsteady cyclic injection mode involves the extraction of oil through production wells and the injection of a liquid working agent into injection wells in a cyclic mode with specified injection parameters. Cyclic mode is performed by repeatedly creating a pulse of reservoir pressure through a combination of injection pressure pulses of different time and amplitude. Change the mode of the working agent injection in the injection well is carried out by the movement in the shut-off device of the closure element. Locking element is performed with a predetermined number and size of the through-holes. Closure element is moved from one predetermined position thereof to another predetermined position, opening or closing a predetermined passage opening for a predetermined time interval. Pulsed flow of the liquid working agent into the injection well is carried out in the state of pulsation, turning into a turbulent mode. Device includes an injection well with wellhead shut-off valves, a stop-by-pass device with a shut-off element and tubing. Closure element is made with the possibility of reciprocating motion. Closure element is moved by means of a control signal from the control station. Control signal is fed to the actuator of the bypass device. Control station includes a control device. Control device is a control computer or a control controller with software.EFFECT: improving the efficiency in oil production from the reservoir, improving the speed of control and the quality of monitoring the process of remote and online control and control of pumping and production of oil.13 cl, 2 dwg, 2 ex

Description

The invention relates to the oil industry and may find application in the development of oil deposits in the oil and gas field, namely, as methods and devices for regulating the flow of fluids during injection into the reservoir, controlled by different injection pulses, compatible with each other, and oil production through controlled depression cyclically variable in time.

A known method of developing an oil reservoir by creating a high reservoir pressure pulse by injecting water into injection wells when production wells are stopped on the reservoir and then putting them into operation when the injection wells are stopped, the formation pressure pulse is created by multiple intensive injection of water into the reservoir with a given duration of creation pulse and change the reservoir pressure, while after creating a reservoir pressure pulse, the production fluid is extracted and wells. (RF patent No. 2176312, ЕВВ 43/20, op. November 27, 2001).

A disadvantage of the known technical solution is that in practice it is very difficult to agree on a suspension for a long period of injection into injection wells and it is even more difficult to stop production wells, since this immediately leads to direct losses in oil production. In addition, the shutdown of production pumping wells is often accompanied by the appearance of technical problems associated with their subsequent commissioning and bringing them to an effective mode of operation, and a prolonged shutdown of the pumps for two weeks or more helps to reduce the MCI and increase premature pump failures.

In addition, this technology is not applicable in the winter period, due to the possibility of freezing of water pipes, reservoirs, wellheads, i.e. A disadvantage of the known technical solution lies in the seasonal nature of the work.

Known Installation for pumping fluid into the reservoir, including an injection well with wellhead shutoff valves, a string of tubing. (RF patent No. 34628, ЕВВ 43 / 00,20, op. 10.12.2003).

The disadvantage of this technical solution is the use of additional equipment such as an electric pump and compensator in the well, which greatly complicates, increases the cost of injection and reduces the overhaul period of its operation due to the use of an electric pump.

Also, this setting is limited in injection control modes, which depend on the characteristics of the electric pump.

The closest technical solutions are:

A method of developing an oil deposit, including the selection of oil through production wells and pumping a working agent into injection wells in a cyclic mode (RF Patent No. 2481465, ЕВВ 43/16, op. 05/10/2013, prototype).

A disadvantage of the known technical solution is that the use of the same injection mode over time reduces the effect of this cyclic injection mode to zero, however, apart from the selected mode, it is not supposed to change over time. The magnitude of the propagation of the pressure pulse in the reservoir as it moves away from the well gradually fades and levels out. Small pulses and short ones in time cover the zone of the formation that is closest to the well, while long and large amplitude pulses affect the remote zone of the formation. Therefore, in order to further increase the oil recovery of a deposit, it is necessary to constantly change the magnitude and duration of the pressure pulse of the injection agent; the injection mode must constantly change.

In addition, this method does not allow the development of an oil reservoir in winter, i.e. it has a seasonal character because when wells are shut down, wells and water conduits will freeze, and there is no hour / minute mode for pumping a working agent in a turbulent pulsed mode into the formation in order to process and clean the bottomhole formation zone from squeezers ..

Installation for pumping fluid into the formation, including a pipeline equipped with wellhead shutoff valves containing a shut-off and bypass device with a shut-off element, an injection well, tubing (RF Patent No. 46808, ЕВВ 43/00, 20, op. July 27, 2005, prototype )

The disadvantage of this technical solution is that it is the use of additional equipment such as an electric pump in the well, which greatly complicates, increases the cost of injection and reduces the overhaul period of its operation due to the use of an electric pump. Also, this setting is limited in injection control modes, which depend on the characteristics of the electric pump.

The proposed technical solutions eliminate the above disadvantages and increase the efficiency of oil production from the reservoir, increasing oil production both by regulating the flow of fluids during injection into the reservoir by different injection cycles, combining pressure pulses of injection of a liquid working agent and oil production of different time and amplitude by means of a controlled depression cyclically changing in time, changing the size of the diameter of the passage opening, the volume and pressure of the liquid working agent injection, and in the developed hall hydrocarbon liquids with a given flow rate of the working agent by creating pulsations to the flow of the working agent and the pulsation rate of supplying this liquid working agent to the reservoir in a pulsating state, controlling the flow of the working agent during unsteady flooding, controlled by short pulses in combination with long pulses of cyclic injection of liquid working agent within a given corridor in the form of a range of working agent injection parameters, with the possibility of saving or not saving the daily volume of its injection, tate in increased oil recovery reservoir (oil recovery factor K = CIN _drawing ⋅K _OHV ⋅K _head (K _deputy)) due to intensification of displacement processes, coverage and flooding (substitution) of oil liquid working agent; Also, the claimed technical solutions increase the efficiency of monitoring and the quality of monitoring the process of remote and online regulation and control of oil injection and production.

This goal is achieved by the fact that the Method of developing an oil field in an unsteady cyclic injection mode involves taking oil through production wells and pumping a liquid working agent into injection wells in a cyclic mode with predetermined injection parameters, while the cyclic mode is carried out by repeatedly generating a reservoir pressure pulse by combining different the time and amplitude of the pressure pulses of the injection of the liquid working agent, the change in the injection mode of the liquid working agent in the supercharger A borehole is carried out by moving a locking element in a shut-off-overflow device with a predetermined number and size of passage openings from one predetermined position to another predetermined position, opening or closing a predetermined passage opening for a predetermined time interval, moving the locking element by means of a control signal from the station control, which is fed to the drive of the shut-off and by-pass device, changing the position of the shut-off element in it, and the pulse supply of liquid work of which the agent is injected into the injection well in a pulsating state, which becomes turbulent, created at the moment the passage opening is opened after the shut-off-bypass device is held in the closed position for a predetermined time interval, the injection mode of the liquid working agent is changed by replacing the shut-off element in the shut-off-by-pass device with a predetermined number of through holes and a given size, the change in the mode of injection of the working agent is carried out by changing the position of the nozzle of the minimum the size of the maximum shut-off element with the specified parameters in the shut-off-transfer device without stopping the injection, providing a change in the pressure drop of the working agent injection from minimum to maximum, in addition, the change in the injection mode of the liquid working agent is carried out when restoring the water cut in the reacting wells to the previous value, the transition is short pulse in a long pulse is carried out by stopping the supply of liquid working agent for a given time and by pitching liquid working agent in the injection well at a predetermined size, the diameter of the hole crossing for a predetermined long time and that short pulses represent a time interval from a few minutes to several dozen hours.

An installation for developing an oil reservoir at an unsteady cyclic injection mode includes an injection well with wellhead shutoff valves, including a shut-off device with a shut-off element and tubing, it is additionally equipped with a control station, a shut-off and shut-off device is additionally equipped with a drive, the shut-off element is configured to generate a pulse reservoir pressure with a given number of through holes and with a given diameter size of these through holes and with the possibility of ne displacements in the process of pumping a working agent from one passage hole to another, while the passage holes are made of one or different diameter sizes, the control station includes a control device connected to the drive, and the control device is a control computer or a control controller with software and the locking element is made to rotate around its axis, moving from one through hole to another, and with the possibility of reciprocating movement, moving from one to another passage hole, the actuator is an electric actuator or an electrohydraulic actuator, while the electric actuator is connected to the shut-off-by-pass device through a common shaft or connecting device, which is a gearbox or chain transmission, the shut-off-by-pass device is a gate valve, which made one-piece or multi-piece, the control device via the communication channel is equipped with a remote control program for the controller and a control computer, a control computer or a control controller with software are programmed remotely via wired or wireless communication.

In FIG. 1 shows an installation for developing an oil field in an unsteady cyclic mode of injection; FIG. 2 shows section AA in FIG. one.

Installation for the development of oil deposits in an unsteady cyclic mode of injection contains an injection well 1 with wellhead shutoff valves, including shut-off and bypass device 2, tubing 3 and a control station 4.

The tubing 3 is a pipe, for example, a pipe with or without couplings, pipe sections of one or different diameters, interconnected, for example, by sub.

The shut-off and overflow device 2 is provided with a drive 5 and is, for example, a shutter with a shut-off element 6, while the shutter 2 is made one-piece or multi-piece.

The locking element 6 is configured to create a reservoir pressure pulse with a predetermined number of through holes 7 and with a predetermined diameter size of these through holes 7.

In the shut-off element 6, the through-openings 7 provide the passage of the liquid working agent with the specified parameters, while the through-openings 7 are made of one or different diameter sizes, and the diameter and number of through-openings 7 depend on the size of the shut-off element 6 and on the injection parameters, including , estimated minimum and maximum injection volumes.

Also, the locking element 6 is made with the possibility of moving during the injection of the liquid working agent from one passage hole 7 to another passage hole 7, for example, by rotation around its axis or reciprocating movement, for example, up and down, providing the opening or closing of a given passage channel shut-off and bypass device 2 in the form of a through hole 7 with a given size; with the ability to quickly replace the locking element 6.

The locking element 6 is, for example, a disk, a disk segment, a plate.

The shut-off-bypass device 2 is installed, for example, in place of a central and / or angular valve in the well reinforcement and / or in the pipe 8 and / or in the comb / flow distributor block in the pipeline with a liquid working agent;

The wellhead shut-off device 2 can be installed together with downhole equipment for pumping a liquid working agent into one or several formations, incl. for simultaneous-separate injection (ARI). For installation in the shut-off-by-pass device 2 of the shut-off element 6 with a given number of passage openings 7 having a predetermined size of the passage diameter, not only the size of the shut-off element 6 itself, but also the task to increase the efficiency of oil production from the reservoir, which depends on number and:

- from injectivity of injection well 1;

- the number and flow rate of producing wells;

- from the compensation volume of the produced products by the injected working agent, for example, if 230-240 m ^{3 of} oil is taken from several wells from a production well or from a given formation zone, then 230-240 m ^{3 of} liquid working agent is pumped into an injection well 1 for a given compensation, either above or below this volume, depending on the task to increase the efficiency of oil production from the reservoir.

For example, in the locking element 6, made in the form of a disk, there are eight through holes 7 of different sizes of diameter: 3, 4, 5, 6, 8, 10, 12, 25 mm.

To pump the liquid working agent at the minimum mode and minimum volume to prevent freezing of the well in winter, an automatic relay can be additionally installed in the shut-off device 2, which switches to the minimum diameter of the through hole 7 instead of putting the well into closed mode.

The actuator 5 is a hydraulic pump or an electric actuator, or an electrohydraulic actuator connected to a shut-off-by-pass device 2 by means of a common shaft or a connecting device, for example, a gearbox or a chain transmission.

The electrohydraulic actuator 5 is a pressure electric pump connected to a shut-off-by-pass device 2 through a hydraulic channel (not shown in Fig.), Which transfers pressure from the pressure-pump to a shut-off-by-pass device 2, moving its shut-off element 6 to various predetermined positions, for example, open position or closed position.

The drive 5 is connected to the control station 4, for example, by means of an electric cable.

The control station 4 is installed with the possibility of connecting to a power source and to drive 5, for example, on a shut-off-over device 2 or in the room of a comb unit, or in a special prepared place: with heating, with insulation, etc., for example, in a sealed box, safe.

The control station 4 is a device that provides automated control of the shut-off and bypass device 2, by automatically starting or shutting off the actuator 5, and can be used, including for controlling downhole equipment.

For example, a device that provides automated control of the shut-off-by-pass device 2 is an electronics unit that includes a modem for remotely transmitting a control signal to drive 5, the control device connected to drive 5 is a control computer or a control controller with software.

The control device via the communication channel is additionally equipped with a remote control program for the controller and the control computer, while the control computer or the control controller with software is remotely programmed via wired or wireless communication.

The installation is additionally equipped with at least one packer 9, a measuring instrument or devices 10, including depth measuring devices, fittings or a fitting 11 located in the through hole 7.

The packer 9 is designed to separate the layers from each other or from the overlying interval and is a disconnecting device, for example, mechanical, hydraulic, with a different installation method in the well.

The control and measuring device 10 is, for example, a flow meter, pressure gauge-thermometer, and is located in the valve and / or shut-off and overflow device 2, and / or at a predetermined depth in the well and is intended to monitor the operation of the injection well 1.

Installation and change of fittings 11 provides a change in the parameters of the flow of the working agent (pressure and flow rate), as well as maintaining a given cyclic (non-stationary) mode of injection of the liquid working agent and the volume of injection of the working agent.

The control station 4 additionally provides control and data transmission from the instrumentation 10, for example, through a modem to the control room, etc.

The method is as follows.

Carry out the selection of oil through production wells, the injection of liquid working agent into injection wells in a cyclic mode with the specified injection parameters.

For this, a tubing 3 or tubing 3 with a cut-off packer or packers 9 is lowered into the injection well, more precisely into the production casing of injection well 1.

At the mouth of the injection well 1, a shut-off-by-pass device 2 is located as part of the wellhead shutoff valve, blocking the flow of the liquid working agent, with a drive 5.

A liquid working agent is, for example, water, alkali, surfactant, etc.

Prior to the start of operation, the Units preset the values of the injection parameters of the liquid working agent in advance, having previously calculated them and setting a specific injection mode for it according to the specified program, taking into account the injection parameters of the liquid working agent:

pressure (p), temperature (Tc), flow rate (Vp), flow rate of the working agent (Q)

and install the locking element 6 corresponding to these predetermined injection parameters into the shut-off-bypass device 2 with a predetermined number of passage openings 7 and with a predetermined diameter size of these passage openings 7, in this case, if the passage openings 7 are larger than required for pumping a liquid working agent, then a certain number of through holes or a hole 7 is pre-plugged or duplicated, using as backup, leaving only a given number of through holes 7 with a given size p opening diameter, providing the remaining through holes 7 specified cyclic (non-stationary) mode of injection of a liquid working agent.

In addition, an additional fitting 11 is installed in the through-hole 7 and control and measuring devices 10 are placed, for example, a flow meter and two pressure gauges, one before and one after the fitting 11 in the shut-off-by-pass device 2 for the possibility of calculating the injection flow rate of the liquid working agent on each fitting 11 according to the pressure drop across the nozzle 11 and to control the daily injection of a liquid working agent, thereby ensuring reservoir pressure control at a predetermined level, which is necessary for calculating the compensation of withdrawals by injection.

Also, before the installation starts, in the control station 4 software, for example, the control controller, the parameters of the specified cyclic (non-stationary) mode of pumping the liquid working agent are introduced in advance in the form of the set values of the parameters of the pump: start and stop pumping the liquid work agent; pressure parameters (p), temperature (Tc), flow rate (Vp), flow rate of the working agent (Q), etc.

The predetermined non-stationary (cyclic) mode of injection of the liquid working agent is controlled, including the time to stop the injection being remotely controlled.

Before injection, the value of the minimum injection pressure of the liquid working agent, at which the formation begins to take in, and the maximum pressure value at which the formation no longer receives, if the formation is absorbing, are only controlled by the injection volumes.

When choosing the parameters of the cyclic mode of injection of a liquid working agent, for example, the opening or closing time of a given passage hole 7, the number and size of the diameter of these passage holes 7 take into account the following:

- ensuring the maximum pressure drop, more precisely, the magnitude of the pressure pulse for intensive impact on the pore space of the formation rocks,

- the number of switching cycles of the injection mode of the working agent - the number (frequency) of pressure pulses in a given period of time;

- ensuring the daily volume of injection of liquid working agent in injection well 1, the corresponding compensation of oil withdrawals from production wells in accordance with the geological and technical measures.

Before cyclic injection of the liquid working agent, the injection well 1 is closed and kept closed for several minutes, for example, for 10 minutes, in winter, the time can be shortened, and it is possible at very low temperatures that the well may not to be closed, and transferred to the injection mode at the minimum size of the diameter of the through hole 7, ensuring the discharge of a small amount of liquid working agent for a predetermined time to prevent freezing.

After that, injection well 1 is opened and drive 5 is put into operation.

Why, from the control station 4, a control signal is supplied to the actuator 5 of the shut-off-by-pass device 2, which repeatedly starts the drive 5 to work, and, accordingly, repeatedly moves the shut-off element 6, repeatedly changing its position in the shut-off-by-pass device 2 to open or closed for a given through hole 7 with a given diameter size for a given time, thereby adjusting the cyclic mode of injection of the liquid working agent and providing the specified values of the parameters of the liquid working agent injection in n gnetatelnuyu well 1.

A liquid working agent begins to flow into the reservoir of injection well 1 in a cyclic injection mode according to a predetermined program.

The cyclic mode with the specified injection parameters is carried out by repeatedly generating a reservoir pressure pulse by combining the pressure pulses of the liquid working agent injection, different in time and amplitude, creating multiple periodic interruptions (pulses) of the liquid working agent injection for a given period of time in combination with the multiple starting of the liquid working agent injection with a given pressure, volume and time.

The created pulses of injection of the liquid working agent due to interruption with a predetermined time and subsequent start of the well for injection are accompanied by its pulsation at the moments of the start of injection, as a result of which the flow rate of the working agent changes and, accordingly, the pulsation of the flow of the working agent reaches, including the mode of its turbulence in the well until the moment it enters the formation, which has the maximum vibration effect on the formation perforation interval.

The duration of short injection pulses is in the time interval from several minutes to several tens of hours, their repeated repeatability provides the maximum high-frequency effect on the perforation interval, the bottomhole formation zone and nearby formation zones up to 30-100 m with maximum pressure drops, contributing to a change in the pressure gradients of the flow of the injected liquid working agent into the reservoir and involvement in the development of additional previously not involved oil reserves. Long pulses in time from more than a day increase the zone of penetration and drainage of the reservoir, thereby increasing the efficiency of drainage of oil in the reservoir.

The change in the mode of injection of the working agent into the injection well 1 is carried out by moving in the shut-off-by-pass device 2 a shut-off element 6 with a predetermined number and size of passage openings 7 from one predetermined position thereof to another predetermined position, opening or closing a predetermined passage opening 7 therein for a predetermined interval time.

In addition, the change in the injection mode of the liquid working agent is carried out

- replacement of the locking element 6 in the locking bypass device 2 with a given number of through holes 7 and with a given size.

- changing the position of the passage hole 7 of the minimum size to the maximum size of the shut-off element with the specified parameters in the shut-off-by-pass device without stopping the injection, providing a change in the pressure drop of the liquid working agent injection from minimum to maximum.

The transition of a short pulse into a long pulse is carried out by injecting a liquid working agent into an injection well at a predetermined size of the diameter of the passage opening for a predetermined long time.

The transition from the injection mode of the liquid working agent with short pulses to the injection mode with long pulses and vice versa is possible with the supply of the liquid working agent stopped in time equal to several minutes or by pumping, or rather draining, the liquid working agent at the minimum diameter of the passage opening 7 for a predetermined time to prevent it from freezing in the winter.

For example, the transition of one mode or injection cycle with short or long pulses to a mode (cycle) with short or long in order to separate the modes (cycles) is carried out by stopping the supply of liquid working agent in time equal to, for example, 10 minutes or more, depending on the set tasks and geological and technical measures.

During the cycle, the locking element 6 is repeatedly moved from a predetermined initial state to a predetermined initial state, for example, the rotation of the disk 6 in one revolution, and the cycle time is set by the speed of movement of the locking element 6, for example, the rotation time of the disk 6 in one revolution.

Multiple movements of the shut-off element 6 from the first through-hole 7 and then to the last through-hole 7, for example, through the closed positions, provide a pulsed flow of the liquid working agent into the injection well 1 in a pulsed state in a given cyclic mode.

The “closed” position for the shut-off-bypass device 2 or injection of a liquid working agent in the winter period at a minimum diameter of the through-hole 7 for a predetermined time of the cyclic mode allows to maximize the pressure pulse of the working agent flow, creating a maximum pressure drop during the installation start-up and, accordingly, the flow rate of the liquid injection working agent to the turbulence regime until the moment it enters the formation, which significantly increases the pulsation of the working agent flow and, accordingly, provides a vibrational effect on the bottomhole formation zone (bottomhole formation zone) of the injection well. Upon reaching the reservoir, the flow of the working agent in a pulsating state enters the reservoir and simultaneously exerts a pulsed vibration effect on the perforation interval, the bottomhole formation zone and further increases the drainage intensity of the remote formation zones, which ultimately increases the efficiency of oil production from the producing reservoir.

The pulsating and non-stationary nature of the change in the pressure of the flow of the working agent strengthens all the processes of energy-mass transfer in the reservoir, including increase the movements and flows of formation fluids from low-permeability rocks to high-permeability reservoirs, from high-pressure zones to low-pressure zones, intensifies capillary impregnation, etc., which in turn allows increasing the efficiency of oil displacement by a liquid working agent.

Periodic cessation or injection of a liquid working agent at a given size of the diameter of the through-hole 7, for example, minimum, and the pulse renewal of the injection of a liquid working agent additionally has a beneficial effect on increasing the productivity of producing wells, reducing their water cut and ultimately increasing the ultimate oil recovery.

The physical meaning of unsteady (cyclic) flooding is determined by “changing the elastic reserve of the reservoir system by periodically increasing and decreasing the injection pressure of the liquid working agent”, which creates unsteady pressure drops and fluid flows between layers of different permeability inside the reservoir. This contributes to the redistribution of fluid in the reservoir due to capillary forces. Moreover, the greatest effect from the use of non-stationary water flooding is observed in heterogeneous productive reservoirs.

A periodic change in the magnitude and direction of the pressure drops in the interlayers of different permeability leads to the penetration of the injected liquid working agent into the zones of the reservoir that are not covered by conventional injection, that is, into stagnant oil zones. All this contributes to the expansion of the boundaries of displacement along the thickness and strike of productive formations. Thus, oil reserves from low-permeability oil-saturated layers, zones and blocks are involved in the development, which leads to a decrease in water cut in production wells.

Moreover, for the implementation of unsteady flooding (cyclic injection mode) using the claimed technical solutions, it does not require significant changes, which include, for example, only replacing the already installed shut-off and overflow devices 2, for example, in the comb unit (COM), with the declared shut-off device a bypass device 2 with a locking element 6, for example, a DMZ multi-position gate valve with an electric actuator 5 controlled remotely or programmatically.

All this allows you to avoid, including manual switching work, to form a programmatically optimal mode of injection, drainage of the reservoir and thereby increase the efficiency of oil production from the reservoir.

Improving the efficiency of oil production from the reservoir under pulsed exposure is carried out, including:

- by increasing the coefficient of coverage of the formation by water flooding during the introduction of the injected agent-water into low-permeability reservoir rocks,

- also due to the intensification of the process of countercurrent capillary impregnation and drainage of oil-saturated stagnant zones of the formation, due to an increase in the speed of fluid movement and an increase in pressure drop, as well as excessive pressure in the formation, there is an increase in the capillary displacement of hydrocarbons by the injection agent from low-permeability reservoirs to flooded highly permeable interlayers.

With constant maintenance of an unsteady injection regime, changes in the volume and pressure of the liquid working agent injection in the hydrocarbon reservoir under development create technological conditions for maintaining an unstable reservoir pressure, which helps to increase the depth of capillary impregnation, respectively, additional coverage of stagnant and previously unreached areas by water flooding.

For example, the automatic multiple changes of position provided by the program during the movement of the shut-off element 6: “open-closed or partially open” at a given through-hole 7 allow a constant basis to maintain in the reservoir an unsteady reservoir pressure that constantly changes within specified limits, which increases the intensity and depth capillary impregnation, and consequently, additional coverage of the reservoir by water flooding and enhanced oil recovery.

Creation of a pulsating cyclic mode of liquid working agent injection using and a cycle with short pulses (not long in time, more precisely, no more than several hours or minutes to a day) of the working agent injection within a given corridor - the range of parameters for pumping liquid working agent, while maintaining the daily prescribed volume Injection, allows, including, not to squam or clean the PPP.

Significantly optimize and intensify the process of regulating the cyclic unsteady mode of injection of a liquid working agent allows

setting a different time for switching from one through-hole 7 to another with the ability to remotely change the time relay of the operation program of the shut-off-by-pass device 2;

registration of indications of control and measuring devices 10 before and after the shut-off and bypass device 2, as well as, for example, the position of the fitting 11 in the through hole 7;

taking readings online from the control and measuring devices 10, setting the control programs of the shut-off-by-pass device 2 remotely, for example, the sequence of installation of the fittings 11 or the closed state, as well as setting the timers 10, the operating time of the cycles, using the ISDK research complex software and transmitting control data through a modem or other communication channel;

connection to the existing field visualization system, for example, the SCADA system);

the use of a shut-off and bypass device 2 in combination with the installation of deep devices 10 in the injection well 1, which significantly increases the information content and the efficiency of cyclic injection.

In a cyclic unsteady mode, the injection of a liquid working agent can withstand restrictions, for example:

1) pressure drop - the maximum, if possible, in the absorbing well maximum maximum injection volume, to provide a more intense impact on the pore space of the formation rocks, especially on its low-permeable part of the reservoir;

2) the number of switching modes, injection cycles - the number of pressure pulses for the intensification of the drainage process of the near and bottom zone of the reservoir - the maximum;

3) the specified boundaries of the change in the coefficient of compensation of the selection by injection, to prevent excessive decrease or increase in reservoir pressure.

Since the shortest injection pulses quickly decay in the near zone of the formation, and they have the maximum effect on the near zone of the formation, and longer time pulses with maximum pressure drops have a farther penetration and, accordingly, have the maximum effect up to the contour of the decay zone, They use a combination of cycles with short pulses and with long pulses in time.

In general, the frequency and duration of the pulses determines the penetration range and the effect of the pulses of the liquid working agent on the oil-bearing formation rock.

Short-term (short) injection pressure pulses provide a deeper cleaning of the PPP squid and, in this case, the pulse decays very quickly already at a short distance, with an increase in the pulse duration and with an increase in the injection volume, the zone of penetration of the pressure pulse into the reservoir increases, which ultimately improves oil recovery.

Due to the use of non-stationary (cyclic) flooding at different injection cycles: a combination of a cycle with short pulses (not long in time, more precisely no more than several hours or minutes to a day) with a cycle with long pulses in time - injection pressure pulses, given that temporary the exposure intervals can be constant or different in time, provide an impact, taking into account the attenuation of the pulse in the formation, to different zones of the oil-containing formation: near and far.

The claimed technical solutions for the first time use cycles with short pulses lasting from several minutes to several tens of hours - up to a day, providing maximum high-frequency impact on the bottomhole formation zone and nearby formation zones up to 30-100 m with maximum pressure drops, injection volumes, contributing to a change in the pressure gradients of the injected flow working agent into the reservoir and involvement in the development of additional previously not involved oil reserves from low-permeability reservoirs, thereby increasing the efficiency l oil production from the reservoir, while using cycles with short pulses in combination with cycles of long pulses.

Very long periods of operation of injection wells within the framework of one injection mode virtually reduce to zero efforts for unsteady (cyclic) flooding, therefore, for example, if the effect of a given injection mode stops at a given nozzle, it is necessary to change the cyclic injection mode in time, for example, with another through hole 7, to ensure changes in pressure and injection volumes, which will contribute to the change in pressure drops and the redistribution of flows in the reservoir.

Studies have shown that after changing the cyclic injection mode (size of the diameter of the through hole, pressure, volume), a decrease in water cut in reacting wells with a different duration is observed, which after some time is restored to the previous value, which is a signal for a further change in the cyclic injection mode.

In this connection, the change in the injection mode of the liquid working agent is also carried out when restoring the water content in the reacting wells to the previous value.

Non-stationary (cyclic) flooding can be carried out at any time of the year.

Example 1

In the injection well 1 with one layer, a tubing 3 is lowered with a packer 8, cutting off the formation from the overlying intervals.

At the mouth there is a wellhead equipment with a shut-off and overflow device 2 in the form of a remotely controlled disk multi-valve valve DMZ with actuator 5.

Before the start of operation, the Units set the parameters of the cyclic mode of injection of the liquid working agent in the form of water:

injection pressure 120 atm,

injection volume 200 m3 / day.

It is necessary to provide:

bottom-hole zone cleaning and increase injectivity of the well with restoration to initial values of injection (injectivity) up to 260 m3 / day.

To ensure these parameters of the cyclic injection mode, a revolver type gate valve 6 is installed in the DMZ 2 butterfly valve, in which there are eight through holes 7 with a diameter size of = 3, 4, 5, 6, 8, 10, 12, 25 mm, while previously plug four passage openings 7 with a diameter size = 4, 6, 8, 12 mm, leaving the four extreme passage openings 7 with a diameter size = 3, 5, 10, 25 mm.

The remaining through holes 7 provide the specified values of the water injection parameters.

Before starting the injection of water in the warm season, close the injection well 1 and keep it closed for 10 minutes.

Then drive 5 is put into operation and into the reservoir of injection well 1 and water enters in a cyclic mode according to a predetermined program.

The cycle is carried out by multiple rotation of the revolver type gate valve 6 in one revolution, namely from the first passage hole 7 with a diameter size = 3 mm, then through the position it is closed to the passage hole 7 with a diameter size = 5 mm, etc. and to the last through hole 7 with a size of 25 mm, while

1 cycle with short pulses: - a short pulse, lasting 30 minutes at each through hole 7, repeating 50 pulses in a row -

water enters the injection well 1 through the through hole 7 with a diameter size = 3 mm, then 5 mm; then 10 mm and sequentially 25 mm, then stopping the supply of the working agent to the well;

2 cycle with long pulses: - long pulse, lasting 12 hours at each through hole 7, repeat 6 pulses in a row -

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the open position for the through hole 7 with a diameter = 3 mm, then 25 mm and water enters the reservoir of the injection well 1, then the supply of the working agent to the well is stopped;

3 cycle with short pulses: - a short pulse, lasting 30 minutes at each through hole 7, repeating 25 pulses in a row

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the position open for the through hole 7 with a diameter of 3 mm, then 25 mm and water enters the reservoir of the injection well 1, then the supply of the working agent to the well is stopped;

4 cycle with long pulses: - long pulse, lasting 18 hours at each passage 7, repeat 2 pulses in a row -

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the position open for the through hole 7 with a diameter of 5 mm, then 10 mm and water enters the reservoir of the injection well 1, then the supply of the working agent to the well is stopped;

5 cycle with short pulses: - short pulse, lasting 60 minutes at each through-hole 7, repeat 12 cycles in a row -

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to a position open to the throughput

openings 7 with diameters of 3, 5, 10, 25 mm and water enters the formation of injection well 1, then stopping the supply of the working agent to the well;

6 cycle with long pulses: - long pulse, lasting 48 hours at each through hole 7, repeat 2 pulses in a row -

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the position open for the through hole 7 with a diameter of 3 mm, then 25 mm and water enters the reservoir of the injection well 1, then the supply of the working agent to the well is stopped;

7 cycle with short pulses: - a short pulse, lasting 60 minutes at each through hole 7, repeat 12 pulses in a row

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the position open for the through hole 7 with a diameter of 3, 5, 10, 25 mm and water enters the reservoir of the injection well 1, then the supply of the working agent to the well is stopped;

since the injectivity was restored to the initial value of up to 260 m3 / day, therefore, there is no longer a need to repeat short cycles (in the case of a decrease in injectivity, you can repeat short cycles again);

8 cycle with long pulses: - long pulse, lasting 96 hours at each through hole 7, repeat 2 pulses in a row -

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the position open for the through hole 7 with a diameter of 3 mm then 25 mm and water enters

reservoir injection well 1, then stopping the flow of the working agent into the well;

9 cycle with short pulses: - long pulse, lasting 120 hours at each through hole 7, repeat 2 pulses in a row -

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the position open for the through hole 7 with a diameter of 3 mm, then 25 mm and water enters the reservoir of the injection well 1, then the supply of the working agent to the well is stopped;

10 cycle with long pulses: - long pulse, lasting 144 hours at each through hole 7, repeat 2 pulses in a row -

after the supply of the working agent is stopped, the revolver type gate valve 6 is rotated to the position open for the through hole 7 with a diameter of 3 mm then 25 mm and water enters the reservoir of injection well 1;

The transition of one cycle to another is carried out by stopping the supply of the working agent in time - between cycles, the supply of the working agent in time is 10 minutes, while the position of the revolver type gate valve 6 is closed for 10 minutes, water does not enter the injection well 1 and, accordingly, does not enter the reservoir.

The cyclic impact on the reservoir is over - the task is achieved through the unsteady impact of injection on the bottomhole formation zone:

PZP cleaning took place during short cycles due to frequent changes in pressure drops and injection volumes and an increase of 30% with the restoration of well injectivity to an initial value of up to 260 m3 / day, therefore, it was no longer necessary to repeat cycles with short pulses (in the case of a decrease in injectivity You can repeat short cycles again;

each cycle with long pulses was monitored and its effectiveness in response to production wells to reduce water cut was determined.

The most effective were the longest five-day impulses (120 and 144 hourly). Perhaps it makes sense to repeat the longest pulses and even increase their duration.

Example 2

An installation including tubing 3, two packers 9 and control and measuring devices 10 as part of an underground arrangement, including two valves with pressure gauges 10 (hereinafter referred to as the “depth valve”) with online data transmission via one for each layer.

At the mouth, wellhead equipment with a shut-off-by-pass device 2 with a drive 5 and a control station 4 is located.

Prior to the start of operation, the Units set the values of the working agent injection parameters in the form of industrial water from the water conduit

with a pressure of 210 atm.,

well injectivity 400 m3 / day (200 m3 / day upper and 200 m3 / day lower formation).

It is necessary to ensure: to increase the injectivity of two layers of the well.

To ensure these parameters, a shut-off element 6 is installed in the form of a plate with two through holes 7 with a size of 3 mm and 25 mm in order to ensure maximum pressure drop and the most “severe” intense impact on the formation.

Fittings 11 with sizes of 3 mm and 25 mm are installed in the through holes 7.

During the injection process, on each nozzle 11, the flow rate and injection pressure of the process water are measured in real time to facilitate injection control, which is necessary to change the injection control program, in the case of a significant increase or decrease in the injectivity of the formations during the injection process.

Information from the depth valves 10 is fed for processing to the control station 4.

The process of pumping technical water into the injection well 1 with two layers is carried out, for example, first to the upper layer, while the depth valve 10 to the lower layer in the closed position, and then to the lower layer, while the deep valve 10 to the upper layer in the closed position.

The process water injection cycle begins by shutting off injection well 1 and keeping it closed for 40 minutes (in winter, time can be shortened).

Then drive 5 is put into operation and the process water in a cyclic mode, according to a predetermined program, enters the upper layer of injection well 1, then to the lower one.

The cycle is carried out by repeatedly moving the plate 6 with two through holes 7 up and down, namely from the upper through hole 7 with a diameter size = 3 mm to the lower through hole 7 with a diameter size = 25 mm through the position of the shut-off and bypass device 2 is closed, while

1 cycle with short pulses: - a short pulse, lasting 60 minutes and 30 minutes on each nozzle 11, repeat 10 cycles in a row

sequentially to the upper and then to the lower reservoirs, such a small cycle with the maximum number of switchings is intended to increase the injectivity of the well by decolming and cleaning the bottom-hole formation zone.

2 cycle with long pulses: - long pulse, lasting 20 hours for 10 hours on each nozzle 11, repeat 2 cycles in a row

with the possibility of increasing up to several days per layer to increase the penetration depth of the pulse.

Short and long pulses create pulsating injection modes.

Short and long pulses are alternately combined to constantly change the pressure in the reservoir, which creates conditions for unsteady flooding of the reservoirs.

The optimal period of cyclic injection and the duration of the periods of injection of wells at given 11 are selected individually for each well or groups of injection wells 1, which vary with time depending on their geological and technological parameters. At the same time, the control computer or the control controller with software is programmed and reprogrammed remotely via wired or wireless communication to more fully account for the changed geological and technical features of the formation.

The use of deep-well and wellhead devices 10 is necessary for conducting thorough online monitoring of cyclic injection using geophysical and hydrodynamic data processing methods.

It should be noted that these cyclic modes are not eternal, they need to be constantly modified, since the efficiency in this mode is not long and after a decrease in water cut in production wells, after some time, the water cut is restored to its original values or then reaches higher water cut values, which requires a transfer of injection wells 1 to another cyclic injection mode for changing the filtration flows and the next reduction in water cut in production wells.

Cyclic injection using multi-union shut-off and bypass devices for unsteady constantly changing distribution of the pressure field in the reservoir can be carried out continuously throughout the life of the wells in the field.

Remote control of the injection of a group of injection wells in the non-stationary waterflooding mode contributes to a deeper change in the filtration flows in the reservoirs and is the most economical and simple method to increase the coverage of the reservoir by injection. Increasing the degree of impact on the bottomhole formation zone using the small-cycle method contributes to increasing vertical waterfill coverage in the context of an opened wellbore and increasing injectivity.

The use of multi-nozzle remotely controlled shut-off and bypass devices greatly facilitates the process of managing the development of a deposit by maintaining reservoir pressure at a given level for a given period of time, as well as periodic and cyclic increases and decreases within specified reservoir pressure levels to intensify flows and change the direction of filtration flows in layers. At the same time, the increase in production occurs due to the redistribution and replacement of oil in the reservoir by the liquid working agent during countercurrent capillary impregnation and increased drainage of the reservoir.

The combination of high and low injection pressures in the process of transferring from one to another through-hole creates conditions for a cyclic pulsed injection mode, when fluid velocities in the reservoir periodically increase significantly and capillary oil displacement by water is enhanced, which contributes to an increase in the displacement coefficient and waterflood coverage of heterogeneous reservoir rocks . The longer and amplitude the pulse (the cycle is longer), the further the pulse penetrates into the formation and the greater the volume of rocks it covers by impact and the formation drains more strongly in the most remote zone. Short and short pulses in the cycle due to fast attenuation have an effect on a small borehole space and are usually used to clean the bottomhole formation zone.

The cyclic effect in combination of cycles with different (short and long) pressure pulses and injection volumes of the liquid working agent enhances the intensity of reservoir drainage, increases the efficiency of the injected water and increases additional production in production wells by reducing their water cut - this provides the task of using multi-pipe remotely and programmatically controlled gate valves with a large number of switches to control unsteady clockwork Ia layers that can increase oil production.

The claimed technical solutions increase the efficiency of oil production from the reservoir due to the cyclic effect combining pressure pulses of different duration and amplitude, and pressure pulses and injection volumes, which:

increases drainage of deposits, reduces water cut and increases oil flow in producing wells, and accordingly,

increases the intensity of the pulse regime of impact and pulsating injection into the reservoir (enhanced oil recovery) by increasing the efficiency of oil flooding with a working agent;

increases the coverage of the formation by displacement in the section and over the area of the reservoir by controlling the flow of the working agent, by supplying and injecting the working agent with adjustable cycles with short pulses (not long in time up to a day) in combination with cycles of long pulses (long in time from day or more );

increases the efficiency of control and monitoring of the mode of injection of the working agent and oil production for the operational change of the cyclic mode when restoring or increasing the water cut in production wells,

changing the parameters of the through-hole, volume and pressure of the working agent injection from the maximum short-term drops and injection volumes between short and long pulses and vice versa and additionally in combination with the short-term shutdown of the liquid working agent in the well or with the short-term supply of the liquid working agent into the well at a minimum size a passage hole from a few minutes to an hour, changing and periodically increasing the speed and volume of the flow of the working agent to enhance the process Ia oil them.

In addition, the proposed technical solutions:

allow regulating the flow of fluids within a predetermined range of parameters for the injection of a liquid working agent during a small-cycle injection, including maintaining the daily injection volume, to prevent the pressure drop in the oil production zone below critical values and, accordingly, fluid flow rates in reacting production wells;

allow oil production through controlled depression, cyclically variable in time, regulated by short and long pulses of the injection cycle,

increase the optimization and intensification of the process of controlling the cyclic mode of injection of a liquid working agent by setting different times for switching from one through-hole to another with the possibility of remotely changing the parameters of the time relay of the shut-off-by-pass device operation program, including triggering the relay by temperature in winter time and automatically switch from the closed position of the shut-off and bypass device to the minimum size of the diameter of the through hole, d To prevent freezing;

recording testimony before and after the shut-off device, as well as, for example, the position of the fitting in the through hole;

taking readings online from measuring devices, setting control programs for the shut-off and by-pass device depending on the current P and T parameters and remotely, for example, the sequence of installation of the fittings or the closed state, as well as setting the timers of the cycle time, using the software of the research complex ISDK with transmission by GSM modem or other type of communication; connection to the existing field visualization system by the type of SCADA system;

the use of a shut-off and overflow device in combination with the installation of downhole and wellhead devices in injection and reactive producing wells, which will significantly increase the information content and efficiency of cyclic injection, all this can additionally provide:

sampling and study of formation fluid samples in reacting producing wells,

measurements by field-geophysical methods of reservoir pressure, temperature and other parameters in each injection cycle.

Claims (17)

1. A method of developing an oil reservoir in an unsteady cyclic injection mode, including the selection of oil through production wells and pumping a liquid working agent into injection wells in a cyclic mode with predetermined injection parameters, characterized in that the cyclic mode is carried out by repeatedly generating a reservoir pressure pulse by combining pressure pulses of injection of a liquid working agent, different in time and amplitude, changing the mode of pumping a working agent into an injection well by moving a shut-off element in a shut-off-by-pass device with a given number and size of through holes from one given position to another predetermined position, while opening or closing a predetermined through hole for a predetermined time interval nor, the pulsed supply of the liquid working agent to the injection well is carried out in a pulsating state, turning into a turbulent mode, created at the moment of opening the passage opening after holding the shut-off-bypass device in the closed position for a predetermined time interval, the shut-off element is moved by means of a control signal from the control station, which is fed to the drive of the shut-off and by-pass device by changing the position of the shut-off element in it. 2. The method according to p. 1, characterized in that the change in the injection mode of the working agent is carried out by replacing the shut-off element in the shut-off and bypass device with a given number of through-holes and with a given size thereof. 3. The method according to p. 1, characterized in that the change in the injection mode of the working agent is carried out by changing the position of the nozzle of the minimum size to the maximum shut-off element with the specified parameters in the shut-off-by-pass device without stopping the injection, providing a change in the pressure drop of the working agent from minimum to maximum . 4. The method according to p. 1, characterized in that the short pulses represent a time interval from several minutes to several tens of hours. 5. The method according to p. 1, characterized in that the transition of a short pulse into a long pulse is carried out by stopping the supply of the working agent for a given time. 6. The method according to p. 1, characterized in that the transition of a short pulse into a long pulse is carried out by pumping a working agent into the injection well at a predetermined size of the diameter of the through hole for a predetermined long time. 7. The method according to p. 1, characterized in that the change in the injection mode of the liquid working agent is carried out when restoring the water content in the reacting wells to the previous value. 8. A device for developing an oil field in an unsteady cyclic mode of injection, including an injection well with wellhead shutoff valves, including a shut-off device with a shut-off element and tubing, characterized in that it is additionally equipped with a control station, the shut-off-by-pass device is additionally equipped with a drive, the shut-off element is made with a predetermined number of through-openings and with a predetermined diameter size of these through-openings with the possibility of pulsed supply of liquid working agent to the injection well at the moment of opening the open-through after holding the shut-off-by-pass devices in the closed position for a predetermined time interval and with the possibility of reciprocating motion, moving in the process akachki working agent from one crossing to another hole, the passage openings are made of the same or different diameter sizes, the control station includes a control device coupled with a drive and control unit is a control computer or controller with control software. 9. The device according to p. 8, characterized in that the drive is an electric drive or electrohydraulic drive, while the electric drive is connected to a shut-off and by-pass device through a common shaft or connecting device, which is a gearbox or chain transmission. 10. The device according to p. 8, characterized in that the shut-off and bypass device is a valve. 11. The device according to p. 8, characterized in that the control device via a communication channel is equipped with a remote control program for the controller and the control computer. 12. The device according to p. 8, characterized in that the valve is made single or multiple. 13. The device according to p. 8, characterized in that the control computer or the control controller with software is programmed remotely via wired or wireless communication.

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