Under-pressure dragging sand washing pipe column for screen sleeve annulus and using method

Abstract

The invention discloses a screen sleeve annulus under-pressure dragging sand washing pipe column and a using method. A sand control pipe column comprises a top packer, a circulating sliding sleeve, an isolation packer and the like. The sand washing pipe column comprises an emergency releasing short section, an unlimited circulating short section, an upper clamping and sealing tool, a vibration unblocking tool, a centralizer, a sliding sleeve closing tool, a sliding sleeve opening and closing tool, an unlimited check valve and a ball supplementing device. By means of the process, annular dragging sand washing operation of the multi-layer sand control pipe column screen sleeve is achieved, sand washing operation from a bottom layer sand control section to an upper layer sand control section is achieved through one-time drilling, circulation channel switches can be established for infinite times, cutting and fishing can be conducted on the sand control pipe column in the later period or secondary sand control is conducted on the original pipe column, the single well treatment period is shortened, and the development cost is reduced; and a new means is provided for later reutilization of the shaft.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum development operations, in particular to a sand flushing pipe column for dragging a screen casing annulus under pressure and a use method thereof. Background Art

[0002] The cutting and processing of sand control pipe string, screen annulus sand flushing and packer during overhaul has always been a difficult and long-term operation. At present, multiple processes are required for processing separately, and cutting, salvaging, casing milling, grinding and milling and other processes, which leads to high cost and long cycle of well repair operation. Therefore, efforts are made to design more efficient well repair tools, which can complete the high-efficiency processing of screen annulus ceramsite under pressure dragging through one trip of pipe string, and then perform conventional cutting and salvaging operations or reuse the original well sand control pipe string. To this end, the present invention develops an efficient processing method for screen annulus under pressure dragging sand flushing pipe string and vibration unblocking. Summary of the invention

[0003] The purpose of the present application is to provide a sand flushing pipe string for dragging the screen casing annulus under pressure and a use method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above objectives, this application provides the following technical solutions:

[0005] A sand flushing pipe string for dragging the screen casing annulus under pressure, comprising:

[0006] A sand control string, wherein the sand control string is provided with a circulation sleeve and a screen sleeve corresponding to each sand control section, each of the circulation sleeves is arranged above each screen sleeve, and the circulation hole on the circulation sleeve is suitable for opening or closing. A top packer is arranged above the sand control string, and the sand control string isolates each sand control section through the isolation packer;

[0007] A sand flushing pipe string extends into the sand control pipe string, and the sand flushing pipe string includes an emergency release short section, an infinite circulation short section, a vibration unblocking tool, a sliding sleeve opening and closing assembly, an infinite check valve and a ball replenisher arranged from top to bottom;

[0008] The emergency release short section is suitable for dropping a ball to separate the drill string from the sand flushing pipe string; the infinite circulation short section is suitable for dropping a ball to open its side wall through hole, and the ball continues to be pressurized to fall into the ball replenisher, and the side wall through hole of the infinite circulation short section is closed; the sleeve opening and closing assembly is used to control the opening and closing of the circulation sleeve.

[0009] Furthermore, a centralizer is provided below the vibration deblocking tool.

[0010] Furthermore, the sleeve opening and closing assembly includes a sleeve closing tool and a sleeve switching tool. The sleeve closing tool is arranged above the sleeve closing tool, and the sleeve closing tool adopts an upward lifting method to close the circulation sleeve; the sleeve switching tool adopts an upward lifting method to close the circulation sleeve and adopts a downward lowering method to open the circulation sleeve.

[0011] Furthermore, an upper sealing tool is provided between the infinite circulation short joint and the vibration plugging removal tool, and the upper sealing tool is used for dragging the sand control pipe string under pressure.

[0012] Furthermore, the unlimited check valve is suitable for closing when the ball is dropped, and the ball continues to be pressurized and falls into the ball replenisher, and the unlimited check valve is opened.

[0013] A method for using the aforementioned screen casing annulus pressure-drag sand flushing pipe string comprises the following steps:

[0014] The sand flushing string is lowered for reverse circulation sand flushing: the circulation holes on each circulation sleeve are closed, and the completion fluid flows through the screen sleeve annulus, ball replenisher, unlimited check valve, sliding sleeve opening and closing assembly, stabilizer, vibration unblocking tool, upper sealing tool, unlimited circulation short section, emergency release short section, and sand flushing string annulus to return to the outside of the well;

[0015] Positive circulation sand flushing: positive circulation sand flushing is performed on each sand control section from bottom to top. When a sand control section is positively circulated and sand flushed, the circulating sleeve corresponding to the sand control section is opened, and the other circulating sleeves are closed. The ball is dropped into the infinite check valve, and the completion fluid flows through the vibration unblocking tool, the screen sleeve annulus, the circulating sleeve, the sand control string annulus, and the annulus returns to the outside of the well to complete the positive circulation sand flushing. The sand flushing string is repeated multiple times from top to bottom in each sand control section;

[0016] If the sand flushing string encounters obstruction, it is necessary to open the emergency circulation channel: drop the ball into the infinite circulation short joint, open the emergency circulation channel, and the completion fluid returns to the outside of the well through the infinite circulation short joint, the screen sleeve annulus, the sand control string annulus, and the annulus to establish an emergency circulation sand flushing channel. If the sand flushing string is unstuck and the sand flushing string is pressurized, the ball falls to the ball replenisher, and the positive circulation sand flushing channel is established again;

[0017] If the sand flushing string encounters resistance and needs to be released: throw a ball into the emergency release nipple to pressurize and separate the sand flushing string and the drilling tool to achieve emergency release;

[0018] Wellbore treatment: The sand control pipe string is processed by conventional cutting, fishing and casing milling;

[0019] Wellbore reuse: Under the premise of ensuring the integrity of the sand control string, secondary filling and sand control are used to reuse the sand control string.

[0020] In summary, the technical effects and advantages of the present invention are as follows:

[0021] The invention is connected with an infinite circulation short joint, an upper sealing tool, a vibration unblocking tool, an infinite check valve, a ball replenisher, etc., realizing infinite circulation channel switch operation, pressure dragging and vibration unblocking functions; the method of the invention realizes the multi-layer sand control pipe column screen sleeve annulus dragging sand flushing operation, realizes the sand flushing operation from the lower sand control section to the upper sand control section in one drilling trip, and can establish an infinite circulation channel switch, which is beneficial to the later cutting and salvaging of the sand control pipe column or the secondary sand control of the original sand control pipe column, shortens the single well processing cycle, reduces the development cost, and provides a new means for the later wellbore reuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a flow chart of a sand flushing string for dragging the screen casing annulus under pressure and a method of using the string in one embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the principle of the "two-step method" construction technology of reverse self-displacing and efficiency-enhancing fracturing of oil wells in one embodiment of the present invention;

[0025] Figure 3 This is a well location map of a certain block B13 well in one embodiment of the present invention;

[0026] Figure 4 This is a production curve diagram of a B13 well fault block in a certain block in one embodiment of the present invention.

[0027] Among them: 1. Emergency release short section; 2. Infinite circulation short section; 3. Upper sealing tool; 4. Vibration unblocking tool; 5. Centralizer; 6. Sleeve closing tool; 7. Sleeve switching tool; 8. Infinite check valve; 9. Ball replenisher; 10. Top packer; 11. Circulation sleeve; 12. Screen; 13. Isolation packer. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] This embodiment provides a method for dragging a sand flushing pipe string under pressure in the screen casing annulus, such as Figure 1-4 As shown, it includes a sand control column and a sand flushing column. The sand control column is an outer column, and the sand flushing column is an inner column. The sand flushing column extends into the sand control column. The sand control column is provided with a circulation sleeve 11 and a screen sleeve corresponding to each sand control section. The circulation sleeve 11 is arranged above the screen sleeve. The circulation hole on the circulation sleeve 11 is suitable for opening or closing. A top packer 10 is arranged above the sand control column. The sand control column isolates each sand control section through an isolation packer 13. Figure 1-4 As shown, this embodiment only shows the structure of the circulating sleeve 11 and the screen sleeve on the sand control pipe column corresponding to the upper sand control section, and the circulating sleeve 11 and the screen sleeve corresponding to the other sand control sections are the same as those of the upper layer.

[0031] The sand flushing pipe string includes an emergency release short section 1, an infinite circulation short section 2, an upper sealing tool 3, a vibration unblocking tool 4, a sliding sleeve opening and closing assembly, an infinite check valve 8 and a ball replenisher 9 arranged from top to bottom;

[0032] In special circumstances, a ball can be thrown into the emergency release short section 1 to separate the drill string from the sand flushing pipe column. The infinite circulation short section 2 is suitable for throwing a ball to open its side wall through hole, establish a local short circuit cycle, continue to pressurize the ball to fall to the ball replenisher 9, the spring thrust ball seat of the infinite circulation short section 2 returns to the initial position, the side wall through hole of the infinite circulation short section 2 is closed, and the infinite circulation short section 2 can be recycled indefinitely. The upper sealing tool 3 is used to drag the sand control pipe column under pressure to form a seal. The sleeve opening and closing assembly is used to control the opening and closing of the circulation sleeve 11.

[0033] In this embodiment, the emergency release short section 1, the infinite circulation short section 2, the upper sealing tool 3, the vibration unblocking tool 4, the sliding sleeve opening and closing assembly, the infinite check valve 8 and the ball replenisher 9 are all commercially available products.

[0034] Furthermore, a centralizer 5 is provided below the vibration plugging removal tool 4. In this embodiment, the centralizer 5 can be designed with a centralizing wing to ensure the centering of the sand flushing pipe string.

[0035] Furthermore, the vibration unblocking tool 4 improves the permeability and compaction degree of the ceramsite in the filling layer through the impact vibration of high-intensity hydraulic shock waves.

[0036] Further, the sleeve opening and closing assembly includes a sleeve closing tool 6 and a sleeve switching tool 7, and the sleeve closing tool 6 is arranged above the sleeve switching tool 7. The sleeve closing tool 6 closes the circulation sleeve 11 by lifting. The sleeve switching tool 7 closes the circulation sleeve 11 by lifting, and opens the circulation sleeve 11 by lowering. When the sand flushing pipe string is lowered, the sleeve switching tool 7 is lowered accordingly. When the sleeve switching tool 7 passes through the upper circulation sleeve, the upper circulation sleeve will be opened. Since the reverse circulation sand flushing requires the circulation sleeve to be closed, the positive circulation sand flushing first flushes the sand control section of the bottom layer, and the upper circulation sleeve needs to be closed. The purpose of setting the sleeve closing tool 6 is to close the upper circulation sleeve. The sleeve closing tool 6 is lifted to close the upper circulation sleeve, and the sand flushing pipe string is continuously lowered. If the lowering height of the sleeve switching tool 7 does not open the bottom circulation sleeve, the bottom circulation sleeve is in a closed state. If the bottom circulation sleeve needs to be opened, the sleeve switching tool 7 needs to be further lowered. For a two-layer sand control section, one sleeve closing tool 6 and one sleeve switching tool 7 are provided. For a multi-layer sand control section, multiple sleeve closing tools 6 and one sleeve switching tool 7 need to be provided, and the number of sleeve closing tools 6 is the number of circulating sleeves minus one. In this embodiment, both the sleeve closing tool 6 and the sleeve switching tool 7 are commercially available products.

[0037] Furthermore, the unlimited check valve 8 is suitable for closing when the ball is dropped, and the ball continues to be pressurized and falls into the ball replenisher 9, and the unlimited check valve 8 is opened.

[0038] This embodiment takes the upper and lower sand control sections as an example to specifically illustrate the method of use. The sand control pipe column is provided with an upper circulating sleeve and an upper screen sleeve corresponding to the upper sand control section, and is provided with a lower circulating sleeve and a lower screen sleeve corresponding to the lower sand control section. The method of use of other multi-layer sand control sections can refer to the method of this embodiment. Figure 1-Figure 4 The diagram only shows the use of the sand control string and the sand flushing string corresponding to the upper sand control section, and the use of the sand control string and the sand flushing string corresponding to the other sand control sections has the same principle as shown in the diagram.

[0039] This embodiment provides a method for using the aforementioned screen casing annulus pressure-drag sand flushing string, comprising the following steps:

[0040] (1) Lower the sand flushing string for reverse circulation sand flushing: The circulation holes on each circulation sleeve are closed. At this time, the sleeve closing tool closes the upper circulation sleeve. The lowering position of the sand flushing string does not cause the sleeve switch tool to open the lower circulation sleeve. Figure 1 As shown, the completion fluid flows through the screen sleeve annulus, ball filler, unlimited check valve, sleeve opening and closing assembly, stabilizer, vibration plugging removal tool, upper sealing tool, unlimited circulation short section, emergency release short section, and sand flushing string annulus and returns to the outside of the well;

[0041] (2) Closing the upper circulation sleeve: lift the sand flushing pipe string to make the sleeve closing tool 2m below the upper circulation sleeve, lift the sleeve closing tool to above the upper circulation sleeve, and use the sleeve closing tool to close the upper circulation sleeve, and ensure that the sleeve opening and closing tool does not pass the upper end surface of the lower circulation sleeve. At this time, the lower circulation sleeve is also closed;

[0042] (3) Opening the lower circulating sleeve: The sleeve closing tool is maintained at the designed height of the upper circulating sleeve, so that the upper circulating sleeve is in a closed state, and the sleeve opening and closing tool is lowered to open the lower circulating sleeve to establish a positive circulation channel; when the lower sand control section is positively circulated and sand is flushed, the lower circulating sleeve is opened and the upper circulating sleeve is closed; when used for multiple sand control sections, each sand control section needs to be positively circulated and sand is flushed from bottom to top. When a sand control section is positively circulated and sand is flushed, the circulating sleeve corresponding to the sand control section is opened, and the remaining circulating sleeves are closed;

[0043] (4) Positive circulation sand flushing: The ball is dropped into the infinite check valve, and the completion fluid flows through the vibration plugging removal tool, the screen sleeve annulus, the circulating sleeve, the sand control string annulus, and the annulus returns to the outside of the well to complete the positive circulation sand flushing; the sand flushing string is repeated multiple times from top to bottom in the lower sand control section;

[0044] (5) Closing the lower circulating sleeve: lift the sand flushing string according to the designed height, and the sleeve closing tool will be lifted accordingly to close the lower circulating sleeve;

[0045] (6) Open the upper circulation sleeve: Continue to lift the sand flushing string to make the sleeve switch tool 2m above the upper circulation sleeve, then lower the sand flushing string, and the sleeve closing tool is lowered accordingly. The sleeve closing tool passes downward through the upper circulation sleeve, and the sleeve closing tool opens the upper circulation sleeve to establish a positive circulation channel. The sand flushing string is lowered to a depth that the sleeve closing tool does not act on the lower circulation sleeve, so that the lower circulation sleeve is in a closed state;

[0046] (7) Positive cycle sand flushing: Figure 2 As shown, the completion fluid flows through the vibration plugging removal tool, the screen sleeve annulus, the circulating sleeve, the sand control string annulus, and the annulus returns to the outside of the well to complete the positive circulation sand flushing; the sand flushing string is repeated multiple times from top to bottom in the upper sand control section;

[0047] (8) If the sand flushing column encounters obstruction, it is necessary to open the emergency circulation channel: Figure 3 As shown, the ball is dropped into the infinite circulation sub, the emergency circulation channel is opened, and the completion fluid is returned to the outside of the well through the infinite circulation sub, the screen sleeve annulus, the sand control string annulus, and the annulus, and the emergency circulation sand flushing channel is established. If the sand flushing string is unstuck and the sand flushing string is pressurized, the ball falls to the ball replenisher, and the positive circulation sand flushing channel is established again;

[0048] (9) If the sand flushing column encounters resistance, it needs to be released: Figure 4As shown in the figure, the ball is thrown into the emergency release short joint to pressurize and separate the sand flushing pipe string and the drilling tool to achieve emergency release;

[0049] (10) Wellbore treatment: The original wellbore sand control pipe string is processed by conventional cutting, fishing and milling;

[0050] (11) Wellbore reuse: Under the premise of ensuring the integrity of the original wellbore sand control string, secondary filling and sand control are used to reuse the original sand control string.

[0051] In summary, the present embodiment is connected with an infinite circulation short joint, an upper sealing tool, a vibration unblocking tool, an infinite check valve, a ball replenisher, etc., realizing infinite circulation channel switch operation, pressure dragging and vibration unblocking functions; the method of the present embodiment realizes the multi-layer sand control pipe screen sleeve annulus dragging sand flushing operation, realizes the sand flushing operation from the lower sand control section to the upper sand control section in one drilling trip, and can establish an infinite circulation channel switch, which is beneficial to the later cutting and salvaging of the sand control pipe or the secondary sand control of the original sand control pipe, shortens the single well processing cycle, reduces the development cost, and provides a new means for the later wellbore reuse.

[0052] Although the preferred implementation cases of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the invention spirit and claims, which all fall within the scope of protection of the present invention.

Claims

1. A sand flushing string for dragging the screen annulus under pressure, characterized in that: include: A sand control string, wherein the sand control string is provided with a circulation sleeve and a screen sleeve corresponding to each sand control section, each of the circulation sleeves is arranged above each screen sleeve, and the circulation hole on the circulation sleeve is suitable for opening or closing. A top packer is arranged above the sand control string, and the sand control string isolates each sand control section through the isolation packer; A sand flushing pipe string extends into the sand control pipe string, and the sand flushing pipe string includes an emergency release short section, an infinite circulation short section, a vibration unblocking tool, a sliding sleeve opening and closing assembly, an infinite check valve and a ball replenisher arranged from top to bottom; The emergency release short section is suitable for dropping a ball to separate the drill string from the sand flushing pipe string; the infinite circulation short section is suitable for dropping a ball to open its side wall through hole, and the ball continues to be pressurized to fall into the ball replenisher, and the side wall through hole of the infinite circulation short section is closed; the sleeve opening and closing assembly is used to control the opening and closing of the circulation sleeve.

2. The sand flushing pipe string for screen casing annulus under pressure dragging according to claim 1, characterized in that: A centralizer is also provided below the vibrating plugging removal tool.

3. The sand flushing pipe string for screen casing annulus under pressure dragging according to claim 1, characterized in that: The sleeve opening and closing assembly includes a sleeve closing tool and a sleeve switching tool. The sleeve closing tool is arranged above the sleeve closing tool, and the sleeve closing tool adopts an upward lifting method to close the circulation sleeve; the sleeve switching tool adopts an upward lifting method to close the circulation sleeve and adopts a downward lowering method to open the circulation sleeve.

4. The sand flushing pipe string for screen casing annulus under pressure dragging according to claim 1, characterized in that: An upper sealing tool is also provided between the infinite circulation short joint and the vibration plugging removal tool, and the upper sealing tool is used for dragging the sand control pipe string under pressure.

5. The sand flushing pipe string for screen casing annulus under pressure dragging according to claim 1, characterized in that: The unlimited check valve is suitable for closing when the ball is dropped, and the ball continues to be pressurized and falls into the ball replenisher, and the unlimited check valve is opened.

6. A method for using the screen casing annulus pressure-drag sand flushing pipe string as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: The sand flushing string is lowered for reverse circulation sand flushing: the circulation holes on each circulation sleeve are closed, and the completion fluid flows through the screen sleeve annulus, ball replenisher, unlimited check valve, sliding sleeve opening and closing assembly, stabilizer, vibration unblocking tool, upper sealing tool, unlimited circulation short section, emergency release short section, and sand flushing string annulus to return to the outside of the well; Positive circulation sand flushing: positive circulation sand flushing is performed on each sand control section from bottom to top. When a sand control section is positively circulated and sand flushed, the circulating sleeve corresponding to the sand control section is opened, and the other circulating sleeves are closed. The ball is dropped into the infinite check valve, and the completion fluid flows through the vibration unblocking tool, the screen sleeve annulus, the circulating sleeve, the sand control string annulus, and the annulus returns to the outside of the well to complete the positive circulation sand flushing. The sand flushing string is repeated multiple times from top to bottom in each sand control section; If the sand flushing string encounters obstruction, it is necessary to open the emergency circulation channel: drop the ball into the infinite circulation short joint, open the emergency circulation channel, and the completion fluid returns to the outside of the well through the infinite circulation short joint, the screen sleeve annulus, the sand control string annulus, and the annulus to establish an emergency circulation sand flushing channel. If the sand flushing string is unstuck and the sand flushing string is pressurized, the ball falls to the ball replenisher, and the positive circulation sand flushing channel is established again; If the sand flushing string encounters resistance and needs to be released: throw a ball into the emergency release nipple to pressurize and separate the sand flushing string and the drilling tool to achieve emergency release; Wellbore treatment: The sand control pipe string is processed by conventional cutting, fishing and casing milling; Wellbore reuse: Under the premise of ensuring the integrity of the sand control string, secondary filling and sand control are used to reuse the sand control string.

Images