Double rubber sleeve packer and thin interbedded reservoir layering water injection method

Abstract

The application discloses a double rubber cylinder packer and a layered water injection method for thin interbedded reservoirs. The double rubber cylinder packer comprises an upper joint, a central pipe, a rubber cylinder component, a setting and unsetting component, a backwashing component and a lower joint. The rubber cylinder component comprises an upper rubber cylinder and a lower rubber cylinder in airtight communication, and the packer further comprises a thrust liquid guide ring arranged between the upper rubber cylinder and the lower rubber cylinder. The pipe wall of the central pipe is axially bored to form a liquid flow channel and a backwashing channel. The outlet position of the liquid flow channel is matched with a corresponding first through hole of the liquid guide ring, so that after the packer is set, the injected fluid can flow out of the packer through the corresponding through hole of the liquid guide ring. The outlet of the backwashing channel is arranged below the lower rubber cylinder, and the backwashing channel is communicated through the liquid guide ring after the packer is set. The packer can realize water injection development of thin oil layers in the thin interbedded reservoir, and water is injected into the thin oil layers through the corresponding through hole of the liquid guide ring between the two rubber cylinders, and the upper and lower rubber cylinders realize sealing functions at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil exploitation, in particular to downhole tools and processes related to oil exploitation, and particularly relates to a double rubber sleeve packer and a layered water injection method for thin interbedded reservoirs. BACKGROUND

[0002] At present, the layered water injection technology mainly develops in the form of "cable control" and "wave code wireless control", such as a cable control type intelligent layered water injection device system (application number CN201821966297.7), a downhole butt joint type layered water injection device with cable for water injection wells (application number CN202220707923.0), a layered water injection device and process method based on downhole wireless communication (application number CN201811198770.6), and a water injection well pressure wave code intelligent layered water injection system (application number CN201821544813.7). The above patents meet the fine layered water injection needs of most multi-layer sections of oil reservoirs. However, in the prior art, the clamping distance between the upper packer and the lower packer in a single layer section (i.e. the thickness of the oil reservoir) must be greater than the sum of the lengths of a single water distributor and a single packer. Due to the length limitation of the existing single-layer water distributor and packer, it is impossible to meet the fine layered water injection needs of multi-layer sections of thin oil layers and thin-thick interbedded oil layers. SUMMARY

[0003] In order to enrich product types, process routes and selection space, the present application provides a double rubber sleeve packer and a layered water injection method for thin interbedded reservoirs, which can realize the water injection development of thin layers in thin interbedded reservoirs.

[0004] In a first aspect, the present application provides a double rubber sleeve packer, which comprises an upper joint, a center pipe, a rubber sleeve component, a setting and unsetting component, a backwashing component and a lower joint. The rubber sleeve component comprises an upper rubber sleeve and a lower rubber sleeve in airtight communication. The packer further comprises a thrust guide ring arranged between the upper rubber sleeve and the lower rubber sleeve.

[0005] The pipe wall of the center pipe is axially drilled with a liquid flow channel and a backwashing channel.

[0006] The outlet position of the liquid flow channel matches the corresponding first through hole of the guide ring, so that after the packer is set, the injected fluid can flow out of the packer through the corresponding through hole of the guide ring.

[0007] The outlet of the backwashing channel is arranged below the lower rubber sleeve, and the backwashing channel is connected through the guide ring after the packer is set.

[0008] Optionally, the pipe wall of the center pipe is circumferentially drilled with a plurality of axial liquid flow channels and a plurality of backwashing channels, and the liquid flow channels and the backwashing channels are arranged alternately.

[0009] Optionally, the pipe wall of the central pipe is further drilled with an axial cable channel, which penetrates through the corresponding through hole of the upper joint and the corresponding through hole of the lower joint.

[0010] Optionally, the upper joint is provided with a through hole matching the position of the liquid flow channel.

[0011] Optionally, the liquid guide ring is provided with a first through hole matching the position of the liquid flow channel, and the first through hole is arranged on a circumference.

[0012] The backwashing channel is divided into an upper section and a lower section, the liquid guide ring is provided with a second through hole, and the number of the second through hole is twice the number of the backwashing channel, the second through hole is arranged on two circumferences, and the upper section of the backwashing channel, the second through hole on one of the circumferences, the second through hole on the other of the circumferences and the lower section of the backwashing channel are sequentially communicated after the packer is set, and the two second through holes are communicated through a connecting bridge.

[0013] Optionally, the upper joint is a plug joint, and the upper end of the upper joint is sleeved with at least one sealing ring.

[0014] In a second aspect, an embodiment of the present application provides a method for layered water injection in a thin interbedded reservoir, which comprises the following steps of setting a double rubber cylinder packer in a water injection well penetrating the thin interbedded reservoir to perform layered water injection.

[0015] The double rubber cylinder packer is set at a position corresponding to a thin oil layer to make the thin oil layer located between the upper rubber cylinder and the lower rubber cylinder of the double rubber cylinder packer.

[0016] At least one of a single control valve cable-through water distributor, a double control valve cable-through water distributor and a single rubber cylinder cable-through packer is set at other positions corresponding to the combination of thin and thick oil layers.

[0017] Optionally, if the thin interbedded reservoir is a single layer of thin and thick layers alternately, and the uppermost oil layer is a thin oil layer, the at least one of a single control valve cable-through water distributor, a double control valve cable-through water distributor and a single rubber cylinder cable-through packer is set at other positions corresponding to the combination of thin and thick oil layers, which comprises the following steps of:

[0018] A single control valve cable-through water distributor is set above the position corresponding to the uppermost thin oil layer to supply water for the double rubber cylinder packer of the thin oil layer.

[0019] If the lowermost oil layer of the thin interbedded reservoir is a thick oil layer, a single control valve cable-through water distributor is set at the position corresponding to the thick oil layer to supply water for the thick oil layer, and a double control valve cable-through water distributor is set at the positions corresponding to other thick oil layers to supply water for the thick oil layers and the double rubber cylinder packers below.

[0020] Optionally, if the thin interbedded reservoir is a single layer of thin and thick layers, and the uppermost oil layer is a thick oil layer, the at least one of the single control valve cable-through water distributor, the double control valve cable-through water distributor and the single rubber sleeve cable-through packer arranged at other corresponding positions according to the combination of thin and thick oil layers comprises:

[0021] The single rubber sleeve cable-through packer is arranged above the corresponding position of the uppermost thick oil layer.

[0022] If the lowermost oil layer of the thin interbedded reservoir is a thick oil layer, a single control valve cable-through water distributor is arranged at the corresponding position of the thick oil layer for water injection of the thick oil layer, and a double control valve cable-through water distributor is arranged at the corresponding position of other thick oil layers for water injection of the thick oil layer and water distribution for the adjacent lower double rubber sleeve packer.

[0023] Optionally, the at least one of the single control valve cable-through water distributor, the double control valve cable-through water distributor and the single rubber sleeve cable-through packer arranged at other corresponding positions according to the combination of thin and thick oil layers comprises:

[0024] If the uppermost oil layer is a thick oil layer, a single rubber sleeve cable-through packer is arranged above the corresponding position of the thick oil layer.

[0025] If two thick oil layers are adjacent to each other, a single rubber sleeve cable-through packer is arranged at the corresponding position between the two adjacent thick oil layers.

[0026] It is judged whether the water distributor at the corresponding position of the thick oil layer needs to distribute water for the adjacent double rubber sleeve packer, if yes, a double control valve cable-through water distributor is arranged at the corresponding position for water injection of the thick oil layer and water distribution for the double rubber sleeve packer, if no, a single control valve cable-through water distributor is arranged at the corresponding position for water injection of the thick oil layer.

[0027] Optionally, the thickness limit between the thick oil layer and the thin oil layer is determined according to the sum of the thickness of the water distributor and the single rubber sleeve cable-through packer.

[0028] Optionally, the thickness limit between the thick oil layer and the thin oil layer is 1.5 meters.

[0029] The beneficial effects of the above technical solutions provided by the embodiments of the present application at least include:

[0030] (1) The double rubber sleeve packer provided by the embodiments of the present application can use a set of setting and releasing components to drive two rubber sleeves, thereby realizing the clamping and sealing of thin oil layers; from the perspective of pipe string technology, the packer only needs to bear the running risk of one packer and only needs to provide the releasing force of one packer, but can realize the functions of two complete packers, and the cost performance is greatly improved; the water injection function is realized through the middle position of the two rubber sleeves, and the water injection development of the thin oil layer can be realized.

[0031] (2) The double rubber sleeve packer provided by the embodiment of the present application has a plug joint as an upper joint, and compared with a conventional nipple connection mode, the plug connection mode shortens the connection distance and is more convenient for setting a liquid flow channel and a backwashing channel on the wall of the central pipe.

[0032] (3) The thin interbedded reservoir layering water injection method provided by the embodiment of the present application uses the double rubber sleeve packer to realize the clamping and sealing of thin oil layers, realizes the water injection function through the middle position of the two rubber sleeves of the double rubber sleeve packer, and cooperates with the existing double-control-valve double-channel water distributor, single-control-valve single-channel water distributor and single rubber sleeve cable-through packer, so that the high integration of the water distributor and the packer can be realized, the tool length is greatly reduced, and the thin oil layer and thin-thick interbedded oil layer layering water injection problem is solved.

[0033] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and attained by the structure particularly pointed out in the written description and claims, and the appended drawings.

[0034] The technical solutions of the present application are described in detail below with the help of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application and explain the present application together with the embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0036] Figure 1 It is an axial sectional view of the existing Y341 packer;

[0037] Figure 2 It is an axial sectional view of the double rubber sleeve packer in the embodiment one of the present application;

[0038] Figure 3 It is a sectional view of a double rubber sleeve packer in the embodiment one of the present application in the "A-A" and "B-B" directions;

[0039] Figure 4 It is a structural view of the double rubber sleeve packer in the embodiment one of the present application;

[0040] Figure 5 It is a thin interbedded reservoir layering water injection schematic view in the embodiment two of the present application;

[0041] Figure 6 It is another thin interbedded reservoir layering water injection schematic view in the embodiment two of the present application. DETAILED DESCRIPTION

[0042] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood, and so that the full scope of the present disclosure is conveyed to those skilled in the art.

[0043] It should be understood that the terms used in the present application merely describe particular embodiments and are not intended to limit the present application. In addition, for numerical ranges in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range within any stated value or stated range, as well as any other stated value or intermediate value in the stated range, is also encompassed within the present application. The upper and lower limits of these smaller ranges can be included or excluded independently from the range.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict between the content of the specification and that of any document incorporated herein by reference, the content of the specification prevails.

[0045] In the description of the present application, it should be noted that the terms "comprising", "including", "having", "containing", and the like, are open-ended terms, i.e., meaning "including, but not limited to".

[0046] Example one

[0047] Figure 1 The schematic diagram of the existing Y341 fluid crossing the packer is shown in the figure, Figure 1 In the figure, 1 is an upper connector, which completes the connection of the packer and the upper tool and the introduction of the fluid; 2 is a center tube, which realizes the fluid crossing through the channel in the tube wall and merges with the backwashing fluid; 9 is a backwashing component containing the backwashing channel 7, which completes the pressure-controlled opening and closing of the backwashing channel; 3 is a rubber sleeve component, which places the rubber sleeve assembly; 10 is a setting and unsetting component, which completes the compression and recovery of the rubber sleeve; 4 is a lower connector, which completes the connection of the packer and the lower tool. Among them, the backwashing component 9, the setting and unsetting component 10 and the lower connector 4 are relatively mature and will not be described in detail. The key design area of the present embodiment is the upper connector 1, the center tube 2 and the rubber sleeve component 3.

[0048] The double rubber sleeve packer provided by the first embodiment of the present application is described with reference to Figures 2-4As shown, the packer includes an upper joint, a central pipe, a rubber sleeve component, a setting and unsetting component, a backwashing component and a lower joint, the rubber sleeve component includes an upper rubber sleeve 31 and a lower rubber sleeve 32 in airtight communication, and the packer further includes a thrust guide ring 5 arranged between the upper rubber sleeve 31 and the lower rubber sleeve 32.

[0049] The pipe wall of the central pipe is axially drilled with a flow channel 6 and a backwashing channel 7.

[0050] The outlet position of the flow channel 6 matches a corresponding first through hole of the thrust guide ring 5, so that, after the packer is set, the injected fluid can flow out of the packer through the corresponding through hole of the thrust guide ring 5.

[0051] The outlet of the backwashing channel 7 is arranged below the lower rubber sleeve 32, and the backwashing channel 7 is communicated through the thrust guide ring 5 after the packer is set.

[0052] The setting and unsetting component can be the setting and unsetting component of the existing Y341 packer, the upper rubber sleeve 31 and the lower rubber sleeve 32 of the present application are in airtight communication, so that the setting and unsetting of the two rubber sleeves can be simultaneously controlled by using a set of existing setting and unsetting components; during setting, the expansion of the upper rubber sleeve 31 and the lower rubber sleeve 32 drives the thrust guide ring 5 to move, so that the flow channel 6 is communicated with the corresponding first through hole of the thrust guide ring 5, and the backwashing channel 7 is communicated through the thrust guide ring 5; after unsetting, the thrust guide ring 5 is reset, so that the flow channel 6 is no longer communicated with the corresponding first through hole of the thrust guide ring 5, and the entire backwashing channel 7 is also no longer communicated.

[0053] The double-rubber-sleeve packer provided by the embodiment one of the present application can use a set of setting and unsetting components to drive two rubber sleeves, thereby realizing the sealing of thin oil layers; from the perspective of pipe string technology, the packer only needs to bear the running risk of one packer and only needs to provide the unsetting force of one packer, but can realize the functions of two complete packers, and the cost performance is greatly improved; the water injection function is realized through the middle position of the two rubber sleeves, and the water injection development of thin oil layers can be realized.

[0054] The upper joint 1 is provided with a through hole matched with the position of the flow channel 6, which is used to complete the connection of the packer and the upper tool and the introduction of the fluid flow, and the lower joint is used to complete the connection of the packer and the lower tool; the lower joint can be arranged in the same way as the lower joint of the existing Y341 packer; different from the pin connection mode of the upper joint of the Y341 packer, the upper joint of the double-rubber-sleeve packer provided by the embodiment of the present application is a plug joint, and at least one sealing ring is sleeved on the upper end of the upper joint. Compared with the conventional pin connection mode, the plug connection mode shortens the connection distance and is more convenient for arranging the flow channel 6 and the backwashing channel 7 on the pipe wall of the central pipe.

[0055] The inlet of the reverse washing channel 7 is consistent with the Y341 packer, and the outlet of the reverse washing channel 7 needs to be arranged below the lower rubber sleeve 32, so that the reverse washing liquid flows out of the packer housing from below the lower rubber sleeve 32. At the same time, it is necessary to ensure that the reverse washing channel is isolated from other liquid flow channels and does not interfere with each other.

[0056] In order to realize the maximum flow channel cross-sectional area, the pipe wall of the center pipe is drilled with a plurality of axial liquid flow channels and a plurality of reverse washing channels in the circumferential direction, and the liquid flow channel 6 and the reverse washing channel 7 can be arranged in a circumferentially uniform and circumferentially staggered manner.

[0057] Further, the double rubber sleeve packer provided by the embodiment of the application is a double rubber sleeve cable control packer, and the pipe wall of the center pipe is further drilled with an axial cable channel 8, which penetrates the corresponding through holes of the upper joint and the corresponding through holes of the lower joint.

[0058] The cable enters from the annulus of the upper water distributor, passes through the cable channel 8 of the double rubber sleeve packer, and exits from the annulus position at the lower end of the double rubber sleeve packer. The liquid flow is introduced from the annulus of the upper water distributor to the position between the two rubber sleeves and flows out of the packer housing, realizing thin layer injection.

[0059] Optionally, the cable channel 8 can also share one liquid flow channel 6, and the cable channel 8 continues to extend to the lower joint and extends out of the annulus until the end of the liquid flow channel 6.

[0060] Since the liquid flow channel 6 and the reverse washing channel 7 form a cross between the two rubber sleeves, it is necessary to circumferentially stagger the radial outflow channel of the liquid flow channel 6 and the axial flow channel of the reverse washing channel 7, and the embodiment is realized by the thrust liquid guide ring 5.

[0061] The thrust liquid guide ring 5 is provided with a first through hole that is consistent in number with the number of the liquid flow channel 6 and matches the position of the liquid flow channel 6, and the first through hole is arranged on one circumference.

[0062] The reverse washing channel 7 is divided into an upper section and a lower section, the thrust liquid guide ring 5 is provided with a second through hole that is twice the number of the reverse washing channel 7, the second through hole is uniformly distributed on two circumferences, and after the packer is set, the upper section of the reverse washing channel, the second through hole matched in position on one of the circumferences, the second through hole matched in position on the other of the circumferences and the lower section of the reverse washing channel are sequentially communicated, and the two second through holes are communicated through a connecting bridge.

[0063] Referring to Figure 3 Fig. 2 is a cross-sectional view of a double rubber sleeve packer provided by the embodiment of the application, and the channel at the 12 o'clock position of the front view is the cable channel 8 (A-A on the right side), the cable enters from the through hole of the upper joint, penetrates the through hole arranged at the corresponding position of the upper end of the thick-walled center pipe, and exits from the lower end of the center pipe, finally penetrates the tool from the corresponding through hole of the lower joint, enters the lower oil sleeve annulus of the packer, and the outlet is sealed by a sleeve.

[0064] In the circumferential direction, there are 8 positions evenly distributed in the main view. Only the through channel of the 12-point position above penetrates the upper and lower ends of the central tube. The remaining channels are all liquid flow channels 6, as shown in the right side of the B-B view in the main view. Figure 3 The liquid flow enters the through hole of the upper joint, and then enters the through hole arranged at the corresponding position on the upper end of the thick-walled central tube. After passing through the upper rubber sleeve 31, the liquid flow radially penetrates out of the rubber sleeve seat and the thrust guide ring 5, and flows out of the tool housing. The liquid flow channel 6 is sealed by an O-ring.

[0065] The other 8 circumferential directions staggered with the 8 evenly distributed positions in the main view are backwash channels 7, as shown in the left side of the A-A view in the main view. Figure 3 After the backwash piston is opened, the backwash liquid flow enters the backwash channel 7 outside the central tube from the annulus of the oil jacket, flows downward, and then enters the inside of the thrust guide ring 5 at the corresponding circumferential position, and realizes cross-penetration with the liquid flow channel 6 inside it. After bypassing the liquid flow outlet of the liquid flow channel 6, it enters the outside of the central tube again, and finally flows out of the tool housing after passing through the lower rubber sleeve 32. The backwash channel 7 is sealed by an O-ring.

[0066] Figure 4 The central tube structure diagram in this embodiment is shown in part, with part of the section being cut away for clarity. The cable channel 8 and the 7 channels circumferentially distributed with it are liquid flow channels 6 (the upper part of the cable channel 8 shares one liquid flow channel 6), and the liquid flow flows radially out of the tool housing from position A. The cable through hole of the cable channel 8 continues to extend downward in the inward protrusion at position B, and penetrates out at the lower end. Figure 4 The backwash channel 7 shown in the main view and the 7 backwash channels 7 circumferentially distributed with it flow into the thrust guide ring from position A, flow into the annular space around the protrusion at position B after passing through the outlet of the liquid flow channel 6, and flow out of the conventional position after passing through the lower rubber sleeve.

[0067] Embodiment two

[0068] Embodiment two of the present application provides a method for layered water injection in a thin interbedded reservoir, comprising the following steps for layered water injection by setting the following in a water injection well drilled through the thin interbedded reservoir:

[0069] Setting the double rubber sleeve packer described in embodiment one above at the corresponding position of the thin oil layer, so that the thin oil layer is located between the upper rubber sleeve and the lower rubber sleeve of the double rubber sleeve packer;

[0070] According to the combination of thin and thick oil layers, at least one of the single control valve cable-through water distributor, double control valve cable-through water distributor and single rubber sleeve cable-through packer is set at other corresponding positions.

[0071] Specifically, if the uppermost oil layer is a thick oil layer, a single rubber over-cable packer is arranged above the position corresponding to the thick oil layer; if two thick oil layers are adjacent, a single rubber over-cable packer is arranged at the position corresponding to each pair of adjacent thick oil layers; it is judged whether the water distributor at the position corresponding to the thick oil layer needs to be a double rubber packer, if yes, a double control valve over-cable water distributor is arranged at the position, for water injection into the thick oil layer and water distribution for the double rubber packer; if no, a single control valve over-cable water distributor is arranged at the position, for water injection into the thick oil layer.

[0072] If the thin interbedded reservoir is a single layer of thin layer and thick layer, and the uppermost oil layer is a thick oil layer:

[0073] A single control valve over-cable water distributor is arranged above the position corresponding to the uppermost thin oil layer, for water distribution for the double rubber packer of the thin oil layer; if the lowermost oil layer of the thin interbedded reservoir is a thick oil layer, a single control valve over-cable water distributor is arranged at the position corresponding to the thick oil layer, for water injection into the thick oil layer; a double control valve over-cable water distributor is arranged at the position corresponding to each other thick oil layer, for water injection into the thick oil layer and water distribution for the double rubber packer below.

[0074] If the thin interbedded reservoir is a single layer of thin layer and thick layer, and the uppermost oil layer is a thick oil layer:

[0075] A single rubber over-cable packer is arranged above the position corresponding to the uppermost thick oil layer; if the lowermost oil layer of the thin interbedded reservoir is a thick oil layer, a single control valve over-cable water distributor is arranged at the position corresponding to the thick oil layer, for water injection into the thick oil layer; a double control valve over-cable water distributor is arranged at the position corresponding to each other thick oil layer, for water injection into the thick oil layer and water distribution for the double rubber packer below.

[0076] Referring to FIG. 1, Figure 5 The thin interbedded reservoir develops thick oil layers (upper thick oil layer), thin oil layers (upper thin oil layer), thick oil layers (lower thick oil layer) and thin oil layers (lower thin oil layer) from top to bottom. A conventional over-cable packer (i.e. single rubber over-cable packer) is arranged above the position corresponding to the upper thick oil layer; a double-channel double rubber over-cable packer (i.e. the double rubber packer provided in the embodiment) is arranged at the position corresponding to the upper thin oil layer; a double control valve cable-controlled water distributor (i.e. double control valve over-cable water distributor) is arranged at the position corresponding to the upper thick oil layer, for water injection into the upper thick oil layer and the upper thin oil layer; a double-channel double rubber over-cable packer is arranged at the position corresponding to the lower thin oil layer; a double control valve cable-controlled water distributor is arranged at the position corresponding to the lower thick oil layer, for water injection into the lower thick oil layer and the lower thin oil layer. Through the above arrangement, the separate layer water injection development of the thin interbedded reservoir can be realized.

[0077] Referring to FIG. 1, Figure 6As shown, the thin interbedded reservoir develops thin oil layer (upper thin oil layer), thick oil layer and thin oil layer (lower thin oil layer) from top to bottom. Double-channel double-gum-cylinder through-cable packer is arranged at the position corresponding to the upper thin oil layer and the position corresponding to the lower thin oil layer respectively; single-control-valve cable-controlled water distributor (i.e. single-control-valve through-cable water distributor) is arranged above the position corresponding to the upper thin oil layer, for water injection for the upper thin oil layer; double-control-valve cable-controlled water distributor is arranged at the position corresponding to the thick oil layer, for water injection for the thick oil layer and the lower thin oil layer.

[0078] It should be understood that the particular order or hierarchy of steps in processes disclosed is an example that can be re-arranged as desired. The particular order or hierarchy of steps in processes disclosed should not be interpreted as reflecting an inherent superiority or inferiority of any steps or features. Embodiments of the application can be carried out with the steps in different orders or hierarchies, without departing from the essence of the application.

[0079] In the foregoing detailed description, various features are grouped together in single embodiments for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are expressly recited in each claim. Rather, as the appended claims reflect, inventive subject matter lies in fewer than all features of the disclosed subject matter used in one or more embodiments. The following claims are hereby expressly incorporated by reference into this detailed description of the disclosed subject matter. Each claim may stand on its own as a separate preferred embodiment of the application.

[0080] The foregoing description includes example of one or more embodiments. Of course, not all possible combinations of components or method steps are described, but one of ordinary skill in the art will recognize that further combinations and permutations of various embodiments are possible. Therefore, the description herein is intended to embrace all such alterations, modifications, and variations that fall within the scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be interpreted as "comprising" rather than "consisting of." Also, where the term "or" is used in either the detailed description or the claims, such term is intended to be interpreted as "nonexclusive or."

Claims

1. A dual packer, comprising an upper sub, a center pipe, a packer element, a setting and unsetting element, a backwash element and a lower sub, characterized in that, The rubber cylinder component comprises an air-tight upper rubber cylinder and a lower rubber cylinder, and the injection function is realized by the middle position of the two rubber cylinders, and the packer further comprises a thrust liquid guide ring arranged between the upper rubber cylinder and the lower rubber cylinder; The pipe wall of the central pipe is drilled with a plurality of axial liquid flow channels and a plurality of axial backwashing channels in the circumferential direction, and the liquid flow channels and the backwashing channels are arranged alternately; The upper joint is provided with a through hole matched with the position of the liquid flow channel; The thrust liquid guide ring is provided with a first through hole matched with the position of the liquid flow channel in number, and the first through hole is arranged on a circle, and the outlet position of the liquid flow channel is matched with the corresponding first through hole of the thrust liquid guide ring, so that after the packer is set, the injected fluid can flow out of the packer through the corresponding through hole of the thrust liquid guide ring; The outlet of the backwashing channel is arranged below the lower rubber cylinder, and the backwashing channel is connected through the thrust liquid guide ring after the packer is set; The backwashing channel is divided into two sections, the thrust liquid guide ring is provided with a second through hole with a number twice that of the backwashing channel, and the second through hole is arranged on two circles, and after the packer is set, the upper section of the backwashing channel, the second through hole matched with the position on one of the circles, the second through hole matched with the position on the other circle and the lower section of the backwashing channel are sequentially connected, and the two second through holes are connected through a connecting bridge.

2. The dual rubber cartridge packer of claim 1, wherein, The pipe wall of the central pipe is further drilled with an axial cable channel, and the cable channel is connected with the corresponding through hole of the upper joint and the corresponding through hole of the lower joint.

3. The dual rubber cartridge packer of claim 1, wherein, The upper joint is a plug joint, and at least one sealing ring is sleeved on the upper end of the upper joint.

4. A method for zonal water injection in a thin interbedded reservoir, characterized in that, The method comprises the following steps of setting in the injection well drilled through the thin interbedded reservoir to perform separate layer injection: A double-rubber-cylinder packer according to any one of claims 1-3 is arranged at the position corresponding to the thin oil layer, so that the thin oil layer is located between the upper rubber cylinder and the lower rubber cylinder of the double-rubber-cylinder packer; At least one of a single-control-valve cable-through water distributor, a double-control-valve cable-through water distributor and a single-rubber-cylinder cable-through packer is arranged at other positions according to the combination of thin and thick oil layers.

5. The method of claim 4, wherein, If the thin interbedded reservoir is a single-layer interbedded reservoir of thin layers and thick layers, and the uppermost oil layer is a thin oil layer, the method of arranging at least one of a single-control-valve cable-through water distributor, a double-control-valve cable-through water distributor and a single-rubber-cylinder cable-through packer at other positions according to the combination of thin and thick oil layers comprises: A single-control-valve cable-through water distributor is arranged above the position corresponding to the uppermost thin oil layer, which is used to distribute water for the double-rubber-cylinder packer of the thin oil layer; If the lowermost oil layer of the thin interbedded reservoir is a thick oil layer, a single-control-valve cable-through water distributor is arranged at the position corresponding to the thick oil layer, which is used to inject water into the thick oil layer; a double-control-valve cable-through water distributor is arranged at the position corresponding to other thick oil layers, which is used to inject water into the thick oil layer and to distribute water for the lower double-rubber-cylinder packer.

6. The method of claim 4, wherein, If the thin interbedded reservoir is a single-layer interbedded reservoir of thin layers and thick layers, and the uppermost oil layer is a thick oil layer, the method of arranging at least one of a single-control-valve cable-through water distributor, a double-control-valve cable-through water distributor and a single-rubber-cylinder cable-through packer at other positions according to the combination of thin and thick oil layers comprises: A single rubber over-cable packer is arranged above the position corresponding to the uppermost thick oil layer; If the lowermost oil layer of the thin interbedded reservoir is a thick oil layer, a single control valve over-cable water injector is arranged at the position corresponding to the thick oil layer for water injection into the thick oil layer; a double control valve over-cable water injector is arranged at the position corresponding to other thick oil layers for water injection into the thick oil layer, and for water injection into the double rubber packer below.

7. The method of claim 4, wherein, The arrangement of at least one of the single control valve over-cable water injector, the double control valve over-cable water injector and the single rubber over-cable packer at the position corresponding to other thick oil layers according to the combination of thin and thick oil layers comprises: If the uppermost oil layer is a thick oil layer, a single rubber over-cable packer is arranged above the position corresponding to the thick oil layer; If two thick oil layers are adjacent to each other, a single rubber over-cable packer is arranged at the position corresponding to the two thick oil layers. If the water injector at the position corresponding to the thick oil layer needs to inject water into the double rubber packer below, a double control valve over-cable water injector is arranged at the position corresponding to the thick oil layer for water injection into the thick oil layer and for water injection into the double rubber packer; if not, a single control valve over-cable water injector is arranged at the position corresponding to the thick oil layer for water injection into the thick oil layer.

8. The method of any one of claims 4 to 7, wherein, The thickness limit between the thick oil layer and the thin oil layer is determined according to the sum of the thickness of the water injector and the single rubber over-cable packer.

9. The method of any one of claims 4 to 7, wherein, The thickness limit between the thick oil layer and the thin oil layer is 1.5 meters.

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