RU128239U1 - DEVICE FOR PULSE LIQUID PUMPING INTO THE LAYER - Google Patents

Abstract

A device for pulsed fluid injection into a reservoir, including a housing with an internal cylindrical sampling, a nozzle concentrically located in the housing with a central channel, windows and a nut, a spring screwed onto an upper end of the nozzle sub, a cylindrical valve rigidly attached to the bottom of the nozzle, inserted into the housing and equipped with on top of the annular protrusion made with the possibility of limited tight movement relative to the inner cylindrical selection of the housing, and the nut is mounted on the outer the surface of the nozzle between the housing and the sub, and the spring is placed between the nut and the housing, while the cavity of the inner cylindrical housing sample above the annular protrusion of the cylindrical valve is communicated by windows with a central channel, and the cavity of the inner cylindrical housing sampling under the annular protrusion of the cylindrical valve is communicated by radial channels with space outside housing, characterized in that the cylindrical valve below the annular protrusion is equipped with two longitudinal grooves located opposite each other opposite which through holes are made in the housing, while a through hole is fixed in the through holes of the housing, inserted into the longitudinal grooves of the cylindrical valve, and inside the cylindrical valve below the nozzle windows a valve cage is rigidly mounted with a shut-off element made in the form of a ball rigidly connected from below with a blind stem, onto which the adjustable sleeve is screwed, while moving relative to the annular protrusion of the cylindrical valve

Description

The proposal relates to the oil and gas industry and can be used in the development of oil fields for pulsed injection of fluid into the reservoir.

A device is known for pumping fluid into a formation (patent RU invent No. 2241825, IPC E21B 43/18, published in Bulletin No. 34 dated December 10, 2004), including a hollow body with a cover, a bottom and exhaust channels for communicating with the body cavity with a bottom hole zone of the well, a movable working body and feed channels for the working agent, while the device is equipped in the upper part of the body with a movable nozzle with support surfaces and an inlet channel in the form of a radial hole for injecting fluid from the bottom hole zone of the well into the feed channels of the working agent with a decrease in mysticity of the well, while the outlet channels communicate one of the cavities of the housing with a cavity under the supporting surfaces of the nozzle, and the feed channels of the working agent are made in the form of a mixing chamber.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts;

- secondly, the complexity of manufacturing parts, such as a movable body, a movable nozzle leads to an increase in the cost of the device;

- thirdly, the low efficiency of the device, since the amplitude of the oscillations of the pulsed fluid injection is not regulated.

A downhole pulsator is also known (patent for utility model RU No. 533363, IPC E21B 43/00, published in Bulletin No. 13 of 05/10/2006), including a housing concentrically placed inside the housing pipe with windows, while the pipe is plugged with a nut and rigidly connected to the sub, a spring-loaded valve, while the pipe is equipped with an internal cylindrical selection, and the valve is made in the form of a hollow cylinder, muffled from below and equipped with an annular protrusion from above; moreover, the annular protrusion of the valve is located in the inner cylindrical sampling of the nozzle, while the valve is equipped with through holes on the side surface and installed in the nozzle with the possibility of tight axial movement within the inner cylindrical sampling of the nozzle with the possibility of partial mutual overlap of the through holes of the valve and the windows of the nozzle.

The disadvantages of this device are:

- firstly, the low efficiency of the device, since the amplitude and frequency of oscillations are not regulated, that during a long injection process at a low flow rate and low frequency of fluid oscillations, the bottom-hole zone of the injection well becomes clogged, which reduces its injectivity, therefore, to accelerate the process of self-cleaning the bottom-hole zones it is necessary to increase the flow rate and pressure of the fluid in the pulse device and create a higher frequency and amplitude of the fluid. To increase the depth of formation cleaning, it is necessary to increase the amplitude, and since the hydraulic resistance of the layers is different, depending on their physicochemical properties, it is necessary to adjust the amplitude and frequency of vibrations in order to select the optimal value for the effective operation of the device;

- secondly, limited functionality, since pulsed fluid injection occurs only at low pressure and low fluid flow rates, which at high pressure, and especially with an increase in fluid flow, leads to the fact that the spring remains practically in a compressed state, due to bringing the device into a stable (constant) download mode.

The closest in technical essence is a device for pulsed injection of fluid into the reservoir (patent for invention RU No. 2400615, IPC E21B 28/00; 43/25, published in bulletin No. 27 of 09/27/2010), including a housing concentrically located in the housing has a nozzle with a central channel, windows and nut, rigidly connected to the sub, a spring, a hollow cylindrical valve equipped with an internal plug and side through holes, and at the top - an annular protrusion made with the possibility of limited tight movement downward relative to the inside a cylindrical sample, while the hollow cylindrical valve is rigidly attached from the bottom to the nozzle, which is inserted into the housing with the possibility of longitudinal tight movement, the nut being installed on the outer surface of the nozzle between the housing and the sub, the spring being installed between the nut and the housing, the inner cylindrical selection in the case, below which in the case equipped with radial channels, the lower cylindrical sample is made, and the holes of the hollow cylindrical valve are made in two p poisons in height, between which an internal plug is installed, the cavity of the inner cylindrical sample of the housing above the protrusion is connected by windows with a central channel, in which technological narrowing is placed above the windows, and the cavity of the internal cylindrical sample of the protrusion is communicated by radial channels with space outside the housing, the lower cylindrical sample which is configured to communicate with the lower row of through holes of the hollow cylindrical valve, and when moving downward relative to the housing - with the upper and lower rows of the through holes of the hollow cylindrical valve at the same time, while the area of the passage section of the narrowing of the Central channel does not exceed the total area of the passage sections of the upper or lower row of through holes.

The disadvantages of this device are:

firstly, the low reliability of the device due to wear of the edges of the lower cylindrical body sample, especially when injecting acids and other corrosive chemicals, which leads to premature communication of the upper and lower row of through holes of the hollow cylindrical valve with each other through the lower cylindrical body sample and, as a consequence, the deviation of the mode (frequency and amplitude) of the pulse injection from the desired mode of operation of the device;

secondly, to control the frequency and amplitude of the pulses generated by the device, a set of interchangeable sleeves is required that are installed in the central channel of the device, depending on the volume of fluid pumped through the device. In addition, the area of the passage section of the narrowing (replaceable sleeve) of the central channel does not exceed the total area of the passage sections of the upper or lower row of through holes, which limits the volume of pulsed fluid injection;

- thirdly, it is not possible to fill the inner space of the tubing string with borehole fluid during the descent of the device into the well, therefore it is necessary to completely fill the tubing string before starting the device, which takes time. In addition, it is not possible to cause fluid circulation, for example when backwashing is necessary.

The objective of the utility model is to increase the reliability of the device with the ability to control the frequency and amplitude of the pulse injection in the required injection volume, as well as with the possibility of filling the tubing string with borehole fluid during descent.

The problem is solved by a device for pulsed fluid injection into the reservoir, including a housing with an internal cylindrical sampling, a nozzle concentrically located in the housing with a central channel, windows and a nut, a spring screwed onto the upper end of the nozzle sub, a cylindrical valve rigidly attached from below to the nozzle, inserted into the casing and equipped with an annular protrusion on top made with the possibility of limited tight movement relative to the inner cylindrical selection of the casing, the nut is installed on the outer surface of the pipe between the housing and the sub, and the spring is placed between the nut and the housing, while the cavity of the inner cylindrical housing sample above the annular protrusion of the cylindrical valve is communicated by windows with a central channel, and the cavity of the inner cylindrical housing sampling under the annular protrusion of the cylindrical valve channels with space outside the enclosure.

What is new is that the cylindrical valve below the annular protrusion is equipped with two longitudinal grooves arranged opposite each other, through holes are made in the housing, while a through-hole is fixed in the through holes of the housing, inserted into the longitudinal grooves of the cylindrical valve, and inside the cylindrical valve below the nozzle windows a valve cage is rigidly installed with a locking member made in the form of a ball rigidly connected from below with a deaf stem onto which an adjustable sleeve is screwed; when moving under the action of excess pressure on the shell upwardly relative annular protrusion of the cylindrical valve rod has the ability to interact with a closure body and a joint axial movement upward within the valve cage.

The figure shows the proposed device for pulsed injection of fluid into the reservoir in longitudinal section.

A device for pulsed fluid injection into the reservoir includes a housing 1 (see Fig.) With an internal cylindrical sampling 2, a pipe 3 concentrically located in the housing 1 with a central channel 4, windows 5 and a nut 6, as well as a spring 7.

An adapter 8 is screwed onto the upper end of the pipe 3. A cylindrical valve 9 is rigidly attached to the pipe 3 below, inserted into the housing 1 and equipped with an annular protrusion 10. The annular protrusion 10 of the cylindrical valve 9 is made with the possibility of limited tight movement relative to the inner cylindrical 2 of the housing 1 sample. A nut 6 is installed on the outer surface of the pipe 3 between the housing 1 and the sub 8. A spring 7 is placed between the nut 6 and the housing 1.

The cavity 11 of the inner cylindrical sample 2 of the housing 1 above the annular protrusion 10 of the cylindrical valve 9 is connected by windows 5 with a central channel 4.

The cavity 12 of the inner cylindrical sample 2 of the housing 1 under the annular protrusion 10 of the cylindrical valve 9 is communicated by radial channels 13 with a space (not shown in FIG.) Outside the housing 1 (see the figure).

The cylindrical valve 9 below the annular protrusion 10 is equipped with two opposed longitudinal grooves 14 and 14 ′, opposite which through holes 15 and 15 ′ are made in the housing 1, respectively.

In the through holes 12 and 12 ′ of the housing 1, for example, a rod 16 is fixed on the thread, inserted into the longitudinal grooves 11 and 11 ′ of the cylindrical valve 9.

Inside the cylindrical valve 9 below the windows 5 of the pipe 3, the valve cage 17 is rigidly mounted with a locking member 18 made in the form of a ball 19 rigidly connected from below with a deaf rod 20.

An adjustable sleeve 21 is screwed onto the blind stem 20, while moving the housing 1 upward of the relative annular protrusion 10 of the cylindrical valve 9, the rod 16 is able to interact with the locking member 18 and their joint axial movement upward within the valve cage 17. The distance L, between the lower end adjustable sleeve 21 of the locking member 18 and the rod 16, is controlled by the degree of wrapping the regulation of the adjustable sleeve 21 in the blind stem 20 of the locking member 18 and allows you to select the desired frequency of amplitude and pulse frequency fluids.

Unauthorized fluid flows are prevented by o-rings.

A device for pulsed injection of fluid into the reservoir works as follows.

Before the device is lowered into the well (not shown in Fig.), The device is adjusted depending on the injectivity of the formation, that is, the optimal mode (oscillation frequency, amplitude) of pulse injection is selected depending on the required injection volume and reservoir injectivity pressure, which is subjected to pulse liquid injection , for example, acid treatment of the formation. To do this, select the stiffness of the spring 7 (see the figure) and adjust the distance - L so that at a certain flow rate of the liquid and pressure the required (optimal) oscillation frequency and pulse amplitude are created. This is carried out empirically, for example, during bench tests.

In the design of the proposed device there is no replaceable sleeve, which significantly limits the volume of pulsed fluid injection.

In the optimal operating mode of the device, the process of impulse exposure to inhomogeneities of a hydrocarbon deposit has significant boundaries, which positively affects the reduction of residual oil saturation (accelerated closed-cell pore impregnation processes) and, as a result, oil recovery in production wells increases.

With an increase in fluid flow, the frequency of oscillations of the fluid increases, and the amplitude of the oscillations of the pulse action on the formation and, accordingly, the pressure drop can be increased by increasing the stiffness of the spring by turning the nut 6 into the nozzle 3 and, conversely, the amplitude of the oscillations of the pulse action by the formation can be reduced and, accordingly, the pressure difference can be reduced by stiffness springs by turning the nut 6 on the nozzle 3.

After adjustment, the device for pulsed fluid injection into the formation is connected to the tubing string with a packer (not shown in the figure) of any known design (for example, a through packer with a P-NMO mechanical axial installation (25 MPa) produced by the scientific Production company "Packer" Oktyabrsky, Republic of Bashkortostan, Russian Federation)

Next, a tubing string with a packer is lowered into the well in (Fig. Not shown), so that the packer is 5-10 m above the top of the formation to be pulsed by pumping fluid, for example, waste water or an acid solution.

During the descent of the device on the tubing string due to the presence of a locking member 18 moving upward within the valve cage 17, the fluid in the borehole freely fills the internal spaces of the device and tubing string, which does not require subsequent filling of the entire internal space of the tubing string, since the borehole the liquid during the descent will flow through the shut-off body 18, which passes from the bottom up, i.e. from the borehole space into the tubing string and partially fill it.

After the device is lowered on the tubing string at a predetermined interval, annulus is sealed for this, the through-hole packer is planted in the well, after which fluid is added to the tubing string, the upper end of the string is tied to a pump unit of any known design, for example, to the CA-320 pump unit .

Then they begin the pulse injection of fluid (for example, acid composition for treating the formation) into the well along the tubing string.

The fluid flow under the pressure created from the wellhead through the central channel 4, and then through the windows 5 of the pipe 4 enters the cavity 11, due to the fact that the shut-off member 18 seals tightly in the valve cage 17, i.e. prevents the flow of liquid from top to bottom along the Central channel 4.

In the cavity 11, the fluid flow under the action of excessive pressure acts on the upper end of the annular protrusion 10 of the cylindrical valve 9, while the housing 1 moves upward relative to the annular protrusion 10 of the cylindrical valve 9 within the inner cylindrical sample 2 of the housing 1 (maximum length - B), compressing spring 7.

where, B is the length of the inner cylindrical sample 2 of the housing 1, mm;

L is the distance from the rod 16 to the lower end of the adjustable sleeve 21 in the transport position, mm;

C is the distance from the upper end of the locking element 18 to the upper end of the valve cage 17 in the transport position, mm

In the process of moving the housing 1 upward, the rod 16 moves with it, which first moves a distance - L, interacts with the locking body 18 through the adjustable sleeve 21 and then their joint (rod 16 and locking body 18) axial movement upward to the distance - C within the valve cell 17, i.e. until the shut-off body 18 rests against the valve cage 17 from the top. As a result of the lifting of the shut-off organ 18 upwards, the liquid is passed from top to bottom through the hole 22 in the valve cage 17 under the device, from where it enters the formation (not shown in the figure), the pressure in the Central channel 4 above the valve cage 17, as well as inside the pipe 3 and in the cavity 11 is sharply reduced and the housing 1 under the action of the return force of the spring 7 falls down relative to the annular protrusion 10 of the cylindrical valve 9 within the inner cylindrical the bumps 2 of the housing 1 (maximum length B), also together with the housing 1, the rod 16 with the locking member 18 goes down. As a result, the locking member 18 seals tightly in the valve cage 17, i.e. prevents the flow of fluid from top to bottom along the Central channel 4, and the flow of fluid under the device and, accordingly, into the reservoir stops, so there is one cycle of pulsed injection of fluid into the reservoir.

These cycles are repeated many times, as described above, while the uniform fluid flow is converted into a pulse, while the housing 1 is cyclically moved relative to the cylindrical valve 9.

In addition, the locking element 18 acts as a check valve, so if necessary, you can perform additional technological operations. For example, backwash, for this, unpack the packer and, by supplying fluid from the wellhead to the annulus of the well, cause circulation along the tubing string, after which the packer will again be planted in the required interval and continue the operation of the device as described above. It is also possible to swab the tubing string, for example, after a pulse acid treatment of the formation, after waiting for a technological pause, lower the swab into the tubing string, for example, using the PKS-5 geophysical elevator and remove the acid reaction products in the reservoir.

The device allows to increase the reliability of the device and to regulate the amplitude and frequency of fluid oscillations using an adjustable sleeve during pulse injection in a wide range of flow and pressure, which improves the efficiency of the device and select the optimal mode for the range of propagation of oscillations (from the point of view of the phase velocity of oscillation and absorption coefficient) in the rock mass taking into account their natural frequencies (shales, limestones and sandstones).

The device also allows for additional technological operations, such as backwashing (after unpacking the packer) or swabbing of the tubing string after an acid reaction in the formation, and also allows filling the tubing string with borehole fluid during descent.

Claims (1)

A device for pulsed fluid injection into a reservoir, including a housing with an internal cylindrical selection, a nozzle concentrically located in the housing with a central channel, windows and a nut, a spring screwed onto the upper end of the nozzle sub, a cylindrical valve rigidly attached to the bottom of the nozzle, inserted into the housing and equipped with on top of the annular protrusion made with the possibility of limited tight movement relative to the inner cylindrical selection of the housing, and the nut is mounted on the outer the surface of the nozzle between the housing and the sub, and the spring is placed between the nut and the housing, while the cavity of the inner cylindrical housing sample above the annular protrusion of the cylindrical valve is communicated by windows with a central channel, and the cavity of the inner cylindrical housing sampling under the annular protrusion of the cylindrical valve is communicated by radial channels with space outside housing, characterized in that the cylindrical valve below the annular protrusion is equipped with two longitudinal grooves located opposite each other opposite which through holes are made in the housing, while a through hole is fixed in the through holes of the housing, inserted into the longitudinal grooves of the cylindrical valve, and inside the cylindrical valve below the nozzle windows a valve cage is rigidly mounted with a shut-off element made in the form of a ball rigidly connected from below with a blind stem, onto which the adjustable sleeve is screwed, while moving relative to the annular protrusion of the cylindrical valve s has the ability to interact with a closure body and a joint axial movement upward within the valve cage.

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