Annular cement squeezing device

Abstract

The invention relates to the technical field of petroleum underground well cementation, in particular to an annular cement squeezing device. The problems that according to an existing cement squeezing method, replacement time is long, replacement is not thorough, and the well cementation quality of the height returning section is poor are solved. The invention provides an annular cement squeezing device. The annular cement squeezing device comprises a conveying mechanism. The conveying mechanism comprises a hose, an insertion pipe and a balancing weight; the intubation tube is connected below the hose, the bottom of the intubation tube is closed, and circulating holes are formed around the intubation tube; the balancing weight is connected to the insertion pipe and used for applying force in the vertical direction to the hose and the insertion pipe so that the hose and the insertion pipe can be always kept in the unfolded state in the vertical direction, the insertion pipe can sink into the cement slurry through the balancing weight arranged below the insertion pipe, and the cement slurry directly flows out of the circulation hole to directly reach an original cement layer. The device does not need to wait for replacement of cement paste and mud sediment, the problem that the cement paste is polluted due to incomplete replacement is avoided, the working time of squeezing and injecting cement is shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum downhole cementing, in particular to an annulus cement squeezing device. Background Art

[0002] In the cementing process, cement return height is often insufficient due to various reasons such as well leakage and insufficient cement usage, thus failing to meet cementing quality requirements. If cement return height is insufficient and cementing quality is unqualified, the well cannot be delivered, and the remedy is usually completed by squeezing cement.

[0003] At present, the commonly used cement squeeze method is to directly inject cement slurry from the wellhead, and use the replacement of cement slurry and mud to increase the cement return height. However, this method has the problem that cement slurry replacement needs to wait for the cement slurry to settle to the bottom of the mud, and the replacement time is long. Incomplete replacement will contaminate the cement slurry, resulting in poor cementing quality in the return height section of the squeeze injection. Summary of the invention

[0004] The invention provides an annular cement squeezing device and an annular cement squeezing method to solve the problems of the prior cement squeezing method, such as long replacement time, incomplete replacement and poor cementing quality in the high return section.

[0005] In order to alleviate the above technical problems, the technical solution provided by the present invention is:

[0006] An annular cement squeezing device comprises a conveying mechanism;

[0007] The delivery mechanism includes a hose, a cannula and a counterweight;

[0008] The cannula is connected to the bottom of the hose, the bottom of the cannula is closed, and flow holes are arranged around it;

[0009] The counterweight is connected to the cannula, and is used to apply a vertical force to the hose and the cannula, so that the hose and the cannula always maintain an expanded state in the vertical direction.

[0010] Furthermore,

[0011] The cannula is inserted into the flexible tube.

[0012] Furthermore,

[0013] The hose is provided with an opening, and when the flow hole and the opening on the hose are in an overlapping state, the medium in the hose can flow out.

[0014] Furthermore,

[0015] A drawstring assembly is arranged below the hose, and a counterweight block is connected to the drawstring assembly.

[0016] Furthermore,

[0017] The pull rope assembly includes a first pull rope and a second pull rope that are symmetrically arranged;

[0018] The first pull rope and the second pull rope are connected below to form a contact point, and the counterweight is connected to the contact point.

[0019] Furthermore,

[0020] At least one counterweight is provided.

[0021] Furthermore,

[0022] Also includes a connecting mechanism;

[0023] The connecting mechanism is detachably connected to the upper part of the conveying mechanism;

[0024] The top of the connecting mechanism is used to connect with external grouting equipment.

[0025] Furthermore,

[0026] The connection mechanism includes a union and a reducer;

[0027] The union and the reducer are detachably connected.

[0028] Furthermore,

[0029] The reducer is detachably connected to the hose.

[0030] A grouting system comprises the annular space cement squeezing device mentioned above.

[0031] Based on the above technical solutions, the technical effects that can be achieved by the present invention are:

[0032] The present invention provides an annular cement squeezing device, comprising a conveying mechanism; the conveying mechanism comprises a hose, a plug and a counterweight; the plug is connected below the hose, the bottom of the plug is closed, and flow holes are arranged around it; the counterweight is connected to the plug, and the counterweight is used to apply vertical force to the hose and the plug, so that the hose and the plug always maintain an expanded state in the vertical direction.

[0033] Since the annular cement squeezing device provided by the present invention replaces the original method of directly injecting cement slurry from the wellhead, the conveying mechanism directly enters the mud, and the counterweight block arranged below the plug tube makes the plug tube sink into the mud instead of floating up due to the high density of the mud. The cement slurry directly flows out from the flow hole to the original cement layer. When using the device, there is no need to wait for the cement slurry to be replaced by the mud sedimentation, thus avoiding the problem of cement slurry being contaminated by incomplete replacement, shortening the working time of cement squeezing, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a structural schematic diagram of the annulus cement squeezing device of the present invention;

[0036] Figure 2 Schematic diagram of the flow path of cement slurry.

[0037] icon:

[0038] 100-transport mechanism; 110-hose; 120-cannula; 130-weight block; 140-flow hole; 150-pull rope assembly;

[0039] 200-connecting mechanism; 210-union joint; 220-reducing joint.

[0040] 300-original cement layer;

[0041] 400 - Mud. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0043] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 indirectly connected 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.

[0045] Embodiment 1

[0046] In the cementing process, the commonly used cement squeeze method is to directly inject cement slurry from the wellhead and increase the cement return height by replacing cement slurry with mud. However, this method has the problem that cement slurry replacement needs to wait for the cement slurry to settle to the bottom of the mud, and the replacement time is long. Incomplete replacement will contaminate the cement slurry, resulting in poor cementing quality in the return height section of the squeeze injection.

[0047] In view of this, the present invention provides an annulus cement squeezing device, including a conveying mechanism 100; the conveying mechanism 100 includes a hose 110, a plug 120 and a counterweight 130; the plug 120 is connected to the bottom of the hose 110, the bottom of the plug 120 is closed, and flow holes 140 are arranged around it; the counterweight 130 is connected to the plug 120, and the counterweight 130 is used to apply vertical force to the hose 110 and the plug 120, so that the hose 110 and the plug 120 always maintain an expanded state in the vertical direction.

[0048] Since the annular cement squeezing device provided by the present invention replaces the original method of directly injecting cement slurry from the wellhead, the conveying mechanism 110 directly enters the mud 400, and the counterweight block 130 arranged below the insert tube 120 allows the insert tube 120 to sink into the mud 400 instead of floating due to the high density of the mud 400. The cement slurry directly flows out from the flow hole 140 to the original cement layer 300. When using the device, there is no need to wait for the cement slurry and the mud 300 to settle and replace, thus avoiding the problem of cement slurry contamination caused by incomplete replacement, shortening the working time of cement squeezing, and improving production efficiency.

[0049] The following is combined with Figure 1-2 The structure and shape of the annular cement squeezing device provided in this embodiment are described in detail:

[0050] like Figure 1 As shown, the annular cement squeezing device provided in this embodiment includes a conveying mechanism 100; the conveying mechanism 100 includes a hose 110, a plug 120 and a counterweight 130, the plug 120 is connected to the bottom of the hose 110, the bottom of the plug 120 is closed, and flow holes 140 are arranged around it; the counterweight 130 is connected to the plug 120.

[0051] During cementing work, the conveying mechanism 100 will enter the well. Due to the complex environment in the well, in order to prevent the hose 110 and the insert tube 120 from being damaged by wear of external foreign objects, the hose 110 is made of tough plastic material and the surface is wrapped with wear-resistant stainless steel, and the insert tube 120 is made of wear-resistant stainless steel pipe with a certain thickness.

[0052] like Figure 1 As shown, the cannula 120 is inserted into the hose 110, and the hose 110 is provided with an opening. When the flow hole 140 and the opening on the hose 110 are in an overlapping state, the medium in the hose 110 can flow out;

[0053] like Figure 2 As shown, when cement slurry enters the hose 110 at a certain pressure through the external cement injection equipment and then flows out from the flow hole 140 on the insert tube 120, because the size of the flow hole 140 is much smaller than the insert tube 120, and because the pressure remains unchanged, the cement slurry will flow out in the form of a jet;

[0054] The purpose of doing this is that since there is mud 400 on the upper part of the original cement layer 300, under the pressure of the upper mud 400, the fluidity of the cement slurry at the lower part is poor. If the bottom is not provided with a plug 120, the cement slurry is directly injected using a hose 110. After a period of injection, the cement slurry will accumulate near the hose 110 and gradually wrap the hose 110, resulting in problems such as increased squeezing time or clogging of the hose 110. By using a plug 120 and setting a flow hole 140, the cement slurry is squeezed outward in the form of a jet, so that the squeezed cement slurry can cover the original cement layer 300 more evenly, which can effectively shorten the time of cement squeezing and avoid the problem of clogging.

[0055] like Figure 1 As shown, a pull rope assembly 150 is arranged below the hose 110, and the counterweight 130 is connected to the pull rope assembly 150; the pull rope assembly 150 includes a first pull rope and a second pull rope that are symmetrically arranged; the first pull rope and the second pull rope are connected below to form a contact point, and the counterweight 130 is connected to the contact point.

[0056] In order to ensure that the hose 110 can pass through irregular channels and smoothly descend into the mud 400 when entering the well, the lower end of the tube 120 is connected to the counterweight 130 using a pull rope assembly 150. In order to prevent the pull rope assembly 150 from being damaged and broken due to the complex environment in the well, causing the counterweight 130 to fall off, the pull rope assembly 150 is preferably made of wear-resistant and high-tensile-strength steel wire.

[0057] Furthermore, at least one counterweight 130 is provided according to the different well depths and the different heights of the mud 400 .

[0058] like Figure 1As shown, it also includes a connecting mechanism 200; the connecting mechanism 200 is detachably connected to the upper part of the conveying mechanism 100; the top of the connecting mechanism 200 is used to connect with an external grouting device; the connecting mechanism 200 includes a union 210 and a reducer 220; the union 210 is detachably connected to the reducer 220; the reducer 220 is detachably connected to the hose 110.

[0059] The hose 110 is connected to the external cementing equipment in a detachable manner, and a connecting mechanism 200 of a suitable size can be selected according to different interfaces of the external cementing equipment to connect the external cementing equipment to the conveying mechanism 100.

[0060] The specific operation steps of the present invention are as follows:

[0061] The first step is to connect the external cementing equipment to the conveying mechanism 100 through the connecting mechanism 200;

[0062] The second step is to put the conveying mechanism 100 into the wellhead so that the counterweight 130 enters the mud 300;

[0063] The third step is to start the external cementing equipment;

[0064] The fourth step is that after a period of squeezing, the mud gradually returns from the wellhead. When the cement slurry overflows from the wellhead, the squeezing is completed and the external cementing equipment is closed.

[0065] The present invention can achieve the following beneficial effects:

[0066] When the conveying mechanism 100 is sunk to the bottom of the mud 400 by the counterweight block 130, the cement slurry is discharged through the flow hole 140 arranged on the insert pipe 120, so that the cement slurry directly contacts the original cement layer 300. The cement slurry can achieve the purpose of squeezing without replacing the mud 400, thereby shortening the squeezing operation time and improving the cementing quality and work efficiency.

[0067] Embodiment 2

[0068] This embodiment includes the annular space cement squeezing device described in the first embodiment, and therefore has all the beneficial effects of the annular space cement squeezing device in the first embodiment, which will not be described in detail here.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An annular cement squeezing device, characterized in that: It comprises a conveying mechanism (100); The conveying mechanism (100) comprises a hose (110), a cannula (120) and a counterweight (130); The insert tube (120) is connected to the bottom of the hose (110), the bottom of the insert tube (120) is closed, and flow holes (140) are arranged around it; The counterweight (130) is connected to the cannula (120), and the counterweight (130) is used to apply a vertical force to the hose (110) and the cannula (120), so that the hose (110) and the cannula (120) always maintain a vertically expanded state.

2. The annulus cement squeezing device according to claim 1, characterized in that: The cannula (120) is inserted into the hose (110).

3. The annulus cement squeezing device according to claim 2, characterized in that: The hose (110) is provided with an opening, and when the flow hole (140) and the opening on the hose (110) are in an overlapping state, the medium in the hose (110) can flow out.

4. The annulus cement squeezing device according to claim 3, characterized in that: A pull rope assembly (150) is arranged below the hose (110), and the counterweight (130) is connected to the pull rope assembly (150).

5. The annulus cement squeezing device according to claim 4, characterized in that: The pull rope assembly (150) comprises a first pull rope and a second pull rope which are symmetrically arranged; The first pull rope and the second pull rope are connected below to form a contact point, and the counterweight (130) is connected to the contact point.

6. The annulus cement squeezing device according to claim 5, characterized in that: At least one counterweight block (130) is provided.

7. The annulus cement squeezing device according to claim 6, characterized in that: Also includes a connecting mechanism (200); The connecting mechanism (200) is detachably connected to the upper part of the conveying mechanism (100); The top of the connecting mechanism (200) is used to connect with external grouting equipment.

8. The annulus cement squeezing device according to claim 7, characterized in that: The connecting mechanism (200) comprises a union joint (210) and a reducer joint (220); The union joint (210) is detachably connected to the reducer joint (220).

9. The annulus cement squeezing device according to claim 8, characterized in that: The reducer (220) is detachably connected to the hose (110).

10. A grouting system, characterized in that: It comprises the annulus cement squeezing device as described in any one of claims 1-9.

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