Pressure adjustment indicating nipple and oil and gas well construction method

Abstract

The invention belongs to the technical field of oil and gas well construction, and particularly relates to a pressure adjustment indication short section and an oil and gas well construction method. The pressure adjustment indicating short section is used for being connected with an underground pipe column to prevent the pressure of the underground pipe column from exceeding a preset pressure value, and comprises a body, a pressure adjusting rod and a pressure adjusting rod, the bypass pipe is connected with an inner cavity of the body; and the throttle valve is arranged on the bypass pipe, and when the pressure in the body exceeds a preset pressure value, the throttle valve is opened.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas well construction, and in particular relates to a pressure adjustment indicating nipple and an oil and gas well construction method. Background Art

[0002] During the liner cementing construction, in order to prevent the cement slurry from flowing back after cementing, a one-way valve is designed at the bottom of the liner string. The one-way valve can prevent the drilling fluid in the wellbore from flowing back into the liner and the drill bit. During the liner delivery process, in order to reduce the force on the one-way valve caused by the height difference of the liquid column inside and outside the pipe and reduce the risk of one-way valve failure, it is necessary to perform grouting operations inside the liner and the drill bit to balance the pressure of the liquid column inside and outside the pipe.

[0003] With the continuous improvement of safety requirements at oil field sites, the grouting method has been changed from open grouting to closed grouting. The disadvantage of closed grouting is that it is difficult to judge whether the drilling fluid is filled, and pressure is easily generated in the pipe column. The design sitting pressure of the liner hanger is generally around 10MPa. When the liner hanger is connected and grouting is carried out, if the pressure rises instantly and exceeds the sitting pressure of the liner hanger, the liner hanger will sit in advance, resulting in the failure of the liner cementing operation.

[0004] Therefore, it is necessary to invent a pressure adjustment indicating short joint and an oil and gas well construction method that can prevent the tail pipe hanger from hanging up prematurely. Summary of the invention

[0005] In view of the above-mentioned technical problems, the present invention aims to provide a pressure adjustment indicating nipple, which can solve at least one of the above-mentioned technical problems.

[0006] The present invention also proposes an oil and gas well construction method, which can solve at least one of the above technical problems.

[0007] According to the present invention, a pressure adjustment indicating nipple is provided, which is used to connect with a downhole tubular string to prevent the pressure of the downhole tubular string from exceeding a preset pressure value. The pressure adjustment indicating nipple comprises:

[0008] ontology;

[0009] a bypass tube connected to the inner cavity of the body;

[0010] The throttle valve arranged on the bypass pipe opens when the pressure in the body exceeds a preset pressure value.

[0011] In a specific embodiment, a pressure gauge is provided on the bypass pipe.

[0012] In a specific embodiment, a joint is provided at the end of the bypass pipe.

[0013] In a specific embodiment, the upper end of the body is connected to a grouting pipeline, and the lower end of the body is connected to a downhole pipe string.

[0014] In a specific embodiment, the pressure adjustment indicating nipple further includes:

[0015] A pressure sealing head arranged at the upper end of the main body, through which fluid can be pumped into the main body;

[0016] A blind plugging head is provided at the lower end of the body.

[0017] In a specific embodiment, the downhole tubular string includes a running drill, a liner hanger and a liner string which are sequentially connected from top to bottom.

[0018] In a specific embodiment, a liner rubber plug is arranged at the upper part of the liner string, and a ball seat, a float collar and a float shoe are arranged in sequence at the lower part of the liner string.

[0019] According to the present invention, there is also provided an oil and gas well construction method, comprising the following steps:

[0020] Step 1, setting a preset pressure value of the pressure adjustment indicating nipple provided by the present invention;

[0021] Step 2: Connect the upper end of the pressure adjustment indicating short joint to the grouting pipeline, and connect the lower end to the downhole pipe string;

[0022] Step three: pumping fluid into the downhole tubing string through the pressure adjustment indicating nipple.

[0023] In a specific embodiment, in the step one, a pressure seal head and a blind seal head are respectively provided at the upper and lower ends of the body of the pressure adjustment indicating short section, and fluid is pumped into the body through the pressure seal head to adjust the throttle valve until the overflow pressure of the throttle valve reaches a preset pressure value.

[0024] In a specific embodiment, in the step 2, the pressure seals and blind seals at the upper and lower ends of the body are removed, and then the upper end of the body is connected to the grouting pipeline, and the lower end is connected to the downhole tubing.

[0025] Compared with the prior art, the advantages of the present application are as follows.

[0026] The present invention provides a pressure adjustment indicating nipple, which has closed grouting, pressure adjustment and indication functions. The pressure adjustment indicating nipple is connected to the uppermost end of the downhole tubular at the wellhead. During grouting, the pressure adjustment indicating nipple cooperates with the top drive or grouting pipeline to perform grouting operations. A pressure gauge is provided on the side to clearly display the current tubular pressure. The throttle valve switch is adjusted to set the overflow pressure so that the overflow pressure is a preset pressure value. When the pressure in the downhole tubular reaches the overflow pressure, the throttle valve channel is opened, thereby preventing the pressure in the downhole tubular from exceeding the preset pressure value.

[0027] When the downhole tubing includes a liner hanger, the overflow pressure (preset pressure value) of the throttle valve is set to be 70% lower than the liner hanger sitting pressure. Under this setting, safe grouting operations are ensured to balance the liquid column pressure inside and outside the tubing, and the risk of liner hanger sitting is effectively eliminated, thereby improving the efficiency of liner cementing construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be described below with reference to the accompanying drawings.

[0029] Figure 1 A schematic diagram of an embodiment of a pressure adjustment indicating nipple provided according to the present invention;

[0030] Figure 2 A schematic diagram of setting a preset pressure value for the pressure adjustment indicating nipple provided by the present invention;

[0031] Figure 3 A schematic diagram of an embodiment of a downhole tubular string provided according to the present invention;

[0032] Figure 4 A schematic diagram of normal grouting of a pressure adjustment indicating short joint according to the present invention;

[0033] Figure 5 It is a schematic diagram of fluid flowing out of the overflow valve when the pressure in the downhole tubing exceeds the preset pressure value.

[0034] The reference numerals in the figures are as follows:

[0035] 20. Pressure adjustment indicating nipple; 21. Main body; 22. Pressure gauge; 23. Throttle valve; 24. Connector; 25. Bypass pipe;

[0036] 31. Pressure sealing head; 33. Blind sealing head;

[0037] 2. Send in drilling tools; 3. Tail pipe hanger; 4. Tail pipe plug; 5. Short casing; 6. Tail pipe string; 7. Ball seat; 8. First connecting tail pipe; 9. Floating hoop; 10. Second connecting tail pipe; 11. Floating shoe.

[0038] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0039] The present invention will be described below with reference to the accompanying drawings.

[0040] It should be noted that the directional terms or qualifiers "upper" and "lower" used in this application are all directed to the referenced Figure 1 They are not intended to define the absolute positions of the components involved, but may vary depending on the specific circumstances.

[0041] Figure 1 The structure of the pressure adjustment indicating short section 20 according to the present invention is shown. Figure 1 As shown, the pressure adjustment indicating nipple 20 mainly includes a body 21 , a bypass pipe 25 and a throttle valve 23 .

[0042] The body 21 is configured as a hollow cylindrical structure, and the fluid can enter the body 21 from the upper end of the body 21 and then flow out of the body 21 from the lower end of the body 21 .

[0043] The bypass tube 25 is disposed on the side wall of the body 21 , and the bypass tube 25 is communicated with the inner cavity of the body 21 , so that the pressure of the inner cavity of the body 21 can be transmitted to the bypass tube 25 .

[0044] The throttle valve 23 is arranged on the bypass pipe 25. When the pressure in the body 21 and the bypass pipe 25 exceeds the overflow pressure of the throttle valve 23, the throttle valve 23 can be automatically opened to make the bypass pipe 25 a passage. In this embodiment, the overflow pressure of the throttle valve 23 is adjusted to be equal to the preset pressure value of the pressure adjustment indicating nipple 20. When the pressure in the body 21 exceeds the preset pressure value, the fluid in the body 21 can be discharged through the bypass pipe 25, thereby preventing the pressure in the body 21 from exceeding the preset pressure value.

[0045] According to the present invention, a pressure response tool is provided on the downhole tubular, and the pressure response tool can be activated under a set pressure to perform a specific action. The preset pressure value is less than the relative set force of the pressure response tool of the downhole tubular. The lower end of the body 21 of the pressure adjustment indicating short section 20 is connected to the downhole tubular, and the upper end of the body 21 is connected to the top drive or grouting pipeline. The grouting operation is carried out through the top drive or grouting pipeline. When the pressure in the downhole tubular exceeds the preset pressure value, the throttle valve 23 can be automatically opened to make the bypass pipe 25 a passage, and the fluid in the body 21 can be discharged through the bypass pipe 25, thereby preventing the pressure in the downhole tubular from exceeding the preset pressure value, thereby preventing the pressure response tool of the downhole tubular from performing the action in advance.

[0046] It is easy to understand that the pressure response tool includes but is not limited to a differential pressure sleeve, a hanger, a packer, etc. The pressure response tool is well known to those skilled in the art and will not be described in detail here. In this embodiment, the pressure response tool is a liner hanger.

[0047] In a preferred embodiment, a pressure gauge 22 is provided on the bypass pipe 25, and the pressure gauge 22 is located between the throttle valve 23 and the body 21. The pressure in the body 21 can be measured in real time by the pressure gauge 22. On the one hand, during the grouting process, the pressure gauge 22 can detect the pressure in the downhole tubular string. On the other hand, when the preset pressure value of the pressure adjustment indicating nipple 20 is set, the pressure gauge 22 can measure the pressure in the body 21.

[0048] In a specific embodiment, a joint 24 is provided at the end of the bypass pipe 25. The joint 24 is used to connect with an overflow pipeline (not shown in the figure).

[0049] In a specific embodiment, Figure 2 As shown, the pressure adjustment indicating nipple 20 further includes a pressure seal 31 and a blind plug 33. When setting the preset pressure value of the pressure adjustment indicating nipple 20, the pressure seal 31 is arranged at the upper end of the body 21, and the blind plug 33 is arranged at the lower end of the body 21. The pressure seal 31 can be connected to a pressurizing device, and the blind plug 33 plugs the lower end of the body 21. After the pressurizing device is started, the body 21 can be pressurized through the pressure seal 31, thereby adjusting the overflow pressure of the throttle valve 23.

[0050] In a specific embodiment, Figure 3 As shown, the downhole tubular column includes a delivery drill 2, a liner hanger 3 and a liner string 6 connected in sequence from top to bottom, and the upper end of the delivery drill 2 is coaxially connected to the lower end of the body 21 of the pressure adjustment indicating short section 20. Further, a liner plug 4 is arranged at the upper part of the liner string 6, and the liner plug 4 is connected to the liner string 6 through a short casing 5. A ball seat 7, a floating collar 9 and a floating shoe 11 are arranged in sequence at the lower part of the liner string 6, and the ball seat 7 is coaxially arranged at the end of the liner string 6, the floating collar 9 is connected to the ball seat 7 through the first connecting liner 8, and the floating shoe 11 is connected to the floating collar 9 through the second connecting liner 10. The liner hanger 3 is the pressure response tool in this article. The overflow pressure of the throttle valve 23 of the pressure adjustment indicating short section 20 is less than the sitting pressure (set pressure) of the liner hanger 3.

[0051] Under this setting, when grouting is required in the downhole tubing, when the pressure in the downhole tubing exceeds the overflow pressure, the throttle valve 23 opens to allow the fluid to be discharged through the bypass pipe 25, thereby preventing the pressure in the downhole tubing from reaching the seating pressure of the liner hanger 3 and preventing the liner hanger 3 from seating prematurely.

[0052] According to the present invention, there is provided an oil and gas well construction method, comprising the following steps.

[0053] Step 1: setting a preset pressure value of the pressure adjustment indicating nipple 20 provided according to the present invention.

[0054] In a specific embodiment, the preset pressure value is less than 70% of the seating pressure of the liner hanger 3. In step 1, a pressure seal 31 and a blind seal 33 are respectively provided at the upper and lower ends of the body 21 of the pressure adjustment indicating nipple 20, and the overflow pressure of the throttle valve 23 is adjusted to the maximum. Then, the fluid is pumped into the body 21 through the pressure seal 31 until the reading of the pressure gauge 22 exceeds the preset pressure value, the throttle valve 23 is opened, and the excess fluid is discharged through the bypass pipe 25. Then, the overflow pressure of the throttle valve 23 is gradually reduced until the reading of the pressure gauge 22 is the preset pressure value, at which time the overflow pressure of the throttle valve 23 is the preset pressure value.

[0055] Step 2: Connect the upper end of the pressure adjustment indicating nipple 20 to the grouting pipeline, and connect the lower end to the downhole pipe string.

[0056] In a specific embodiment, after step 1 is completed, the pressure seals 31 and blind seals 33 at the upper and lower ends of the body 21 are first removed, and then the upper end of the body 21 is connected to the grouting pipeline, and the lower end is connected to the downhole pipe string.

[0057] Step three: pump fluid into the downhole tubing string through the pressure adjustment indicating nipple 20.

[0058] like Figure 4 As shown, when fluid is pumped into the downhole tubular column through the pressure adjustment indicating short joint 20, during the normal grouting process, the fluid is injected downward into the downhole tubular column through the body 21. Figure 5 As shown, when the pressure in the downhole tubing exceeds a preset pressure value, the fluid is discharged through the bypass pipe 25 .

[0059] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0060] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pressure adjustment indicating nipple, characterized in that: Used to connect with the downhole tubular string to prevent the pressure of the downhole tubular string from exceeding a preset pressure value, the pressure adjustment indicating nipple includes: Ontology(21); a bypass tube (25) connected to the inner cavity of the body (21); and A throttle valve (23) is arranged on the bypass pipe (25), and when the pressure in the body (21) exceeds a preset pressure value, the throttle valve (23) opens.

2. The pressure adjustment indicating nipple according to claim 1, characterized in that: A pressure gauge (22) is provided on the bypass pipe (25).

3. The pressure adjustment indicating nipple according to claim 1, characterized in that: A joint (24) is provided at the end of the bypass pipe (25).

4. The pressure adjustment indicating nipple according to any one of claims 1 to 3, characterized in that: The upper end of the body (21) is connected to a grouting pipeline, and the lower end of the body (21) is connected to a downhole pipe string.

5. The pressure adjustment indicating nipple according to any one of claims 1 to 3, characterized in that: The pressure adjustment indicating nipple also includes: a pressure sealing head (31) arranged at the upper end of the body (21), through which fluid can be pumped into the body (21); and A blind plugging head (33) is provided at the lower end of the body (21).

6. The pressure adjustment indicating nipple according to any one of claims 1 to 3, characterized in that: The downhole pipe string comprises a running drill tool (2), a liner hanger (3) and a liner string (6) which are connected in sequence from top to bottom.

7. The pressure adjustment indicating nipple according to claim 6, characterized in that: A tail pipe rubber plug (4) is arranged on the upper part of the tail pipe string (6), and a ball seat (7), a floating collar (9) and a floating shoe (11) are arranged in sequence on the lower part of the tail pipe string (6).

8. An oil and gas well construction method, characterized in that: The steps include: Step 1, setting a preset pressure value of the pressure adjustment indicating nipple according to any one of claims 1 to 7; Step 2: Connect the upper end of the pressure adjustment indicating short joint to the grouting pipeline, and connect the lower end to the downhole pipe string; Step three: pumping fluid into the downhole tubing string through the pressure adjustment indicating nipple.

9. The oil and gas well construction method according to claim 8, characterized in that: In the step 1, a pressure seal (31) and a blind seal (33) are respectively provided at the upper and lower ends of the body (21) of the pressure adjustment indicating short section, and fluid is pumped into the body (21) through the pressure seal (31) to adjust the throttle valve (23) until the overflow pressure of the throttle valve (23) reaches a preset pressure value.

10. The oil and gas well construction method according to claim 9, characterized in that: In the second step, the pressure sealing head (31) and the blind sealing head (33) at the upper and lower ends of the body (21) are removed, and then the upper end of the body (21) is connected to the grouting pipeline, and the lower end is connected to the downhole pipe string.

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