Cement cleaning device and method

Abstract

The present application discloses a cleaning device and method for cementing cement, and relates to the field of oilfield well repair operations. The device comprises: a sand mixing liquid delivery pipe and a hydraulic cement cutting ring tool for conveying sand mixing liquid; the sand mixing liquid delivery pipe is connected to the hydraulic cement cutting ring tool, and the sand mixing liquid delivery pipe is used to convey the sand mixing liquid to the hydraulic cement cutting ring tool; the hydraulic cement cutting ring tool comprises a nozzle base assembly and a nozzle, and the nozzle is arranged on the bottom surface of the nozzle base assembly; the radial thickness of the nozzle base assembly matches the annular space where the cementing cement is located between two layers of completion casings. The cementing cement is cut by setting the sand mixing liquid delivery pipe and the hydraulic cement cutting ring tool, and the cementing cement is cut into fragments of different sizes, and the cementing cement is cleaned by using the sand mixing liquid as an impact, so as to avoid mechanical damage to the completion casing, improve the safety and cleaning efficiency in the cementing cement cleaning process, and improve the cleaning effect.

Description

Technical Field

[0001] The disclosed embodiments relate to the field of oilfield well repair operations, and in particular to a device and method for cleaning cement. Background Art

[0002] During oilfield production, when the oil layer casing of an oil or water well is damaged, it can be repaired by removing and replacing the damaged casing. Usually, oil or water wells are structures in which the surface casing is sleeved on the outer periphery of the oil layer casing, and the annular space between the surface casing and the oil layer casing of some wells is filled with cement. The cement must be processed before removing the oil layer casing.

[0003] In the related art, the process commonly used in cement processing is milling, which is a mechanical crushing method, that is, the milling tool is inserted and then the pipe column is rotated to grind the cement to achieve the purpose of cleaning the cement.

[0004] However, when cement is cleaned in the above manner, since the cleaning means adopted is mechanical crushing means, there are prominent disadvantages such as damage to the surface casing and drill jamming, and the workload during the cleaning process is large and the operation cycle is long. Summary of the invention

[0005] The embodiment of the present disclosure provides a cement cleaning device and method, which can improve the safety and cleaning efficiency of cement cleaning. The technical solution is as follows:

[0006] On the one hand, a cleaning device for cementing is provided, the cleaning device comprising: a sand mixing liquid delivery pipe for delivering the sand mixing liquid and a hydraulic cutting cement ring tool;

[0007] The sand mixing liquid delivery pipe is in communication with the hydraulic cement cutting tool, and the sand mixing liquid delivery pipe is used to deliver the sand mixing liquid to the hydraulic cement cutting tool;

[0008] The hydraulic cutting cement ring tool comprises a nozzle base assembly and a nozzle, wherein the nozzle is arranged on the bottom surface of the nozzle base assembly;

[0009] The radial thickness of the nozzle base assembly matches the annular space between two layers of completion casing where the cementing cement is located.

[0010] In an optional embodiment, the two layers of completion casing include a first completion casing and a second completion casing, the first completion casing is sleeved on the periphery of the second completion casing, and the cementing cement is poured between the first completion casing and the second completion casing.

[0011] In an optional embodiment, the radial thickness of the nozzle base assembly is less than half of the radial thickness difference between the first completion casing and the second completion casing, wherein the radial thickness difference is the difference between the completion casing inner diameter of the first completion casing and the completion casing outer diameter of the second completion casing.

[0012] In an optional embodiment, the second completion casing includes a coupling pipe section and a deformed pipe section;

[0013] The outer diameter of the coupling pipe section is greater than the outer diameter of the deformed pipe section, and the radial thickness difference is the difference between the inner diameter of the completion casing of the first completion casing and the outer diameter of the coupling pipe section;

[0014] The outer diameter of the coupling pipe section is less than or equal to the outer diameter of the deformed pipe section, and the radial thickness difference is the difference between the inner diameter of the first completion casing and the outer diameter of the deformed pipe section.

[0015] In an optional embodiment, the first completion casing is a surface casing;

[0016] The second completion casing is an oil layer casing.

[0017] In an optional embodiment, the hydraulic cutting cement ring tool includes a fixed nozzle and a rotating nozzle;

[0018] The fixed nozzle is fixed vertically to the nozzle base assembly;

[0019] The spraying direction of the rotary nozzle changes in rotation during the spraying process of the sand mixing liquid.

[0020] In an optional embodiment, the nozzle base assembly is in a circular ring shape or a crescent shape.

[0021] In an optional embodiment, the sand mixing liquid is obtained by mixing ground liquid and quartz sand in a preset ratio.

[0022] In an optional embodiment, an eccentric liquid inlet is provided on the upper plane of the nozzle base assembly, and the liquid inlet is connected to the hollow sand mixing liquid delivery pipe;

[0023] Each nozzle on the nozzle base assembly has a separate liquid inlet channel.

[0024] On the other hand, a method for cleaning cement is provided, the method comprising:

[0025] A cleaning device for controlling cementing cement is inserted into the annular space between two layers of completion casings, wherein the cleaning device includes a sand mixing fluid delivery pipe and a hydraulic cement ring cutting tool;

[0026] The sand-mixing liquid is delivered to the hydraulic cement ring cutting tool through the sand-mixing liquid delivery pipe, wherein the hydraulic cement ring cutting tool comprises a nozzle base assembly and a nozzle;

[0027] Controlling the nozzle base assembly to a position within a preset distance range from the cementing cement;

[0028] The sand mixing liquid is sprayed through the nozzle.

[0029] The beneficial effects brought by the technical solution provided by the embodiments of the present disclosure include at least:

[0030] By arranging a sand mixing liquid delivery pipe and a hydraulic cement ring cutting tool, the sand mixing liquid is delivered to the hydraulic cement ring cutting tool through the sand mixing liquid delivery pipe, and the sand mixing liquid is sprayed to the position where the cementing cement is located through the hydraulic cement ring cutting tool to cut the cementing cement into fragments, and the cementing cement is cleaned by the impact of the sand mixing liquid to avoid drill sticking, thereby improving the safety and cleaning efficiency in the cementing cement cleaning process and improving the cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is a structural block diagram of a cleaning device for cementing cement provided by an exemplary embodiment of the present disclosure;

[0033] Figure 2 is a structural block diagram of a cleaning device for cementing cement provided by another exemplary embodiment of the present disclosure;

[0034] Figure 3 The figure is a flow chart of a method for cleaning cement provided by an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0036] During oilfield production, when the shallow oil layer casing of an oil or water well is damaged, it can be repaired by removing and replacing the damaged casing. Usually, oil or water wells have a structure in which the surface casing is sleeved on the outer periphery of the oil layer casing, and the annular space between the surface casing and the oil layer casing of some wells is filled with cement. The cement must be processed before removing the oil layer casing.

[0037] In the related art, the process commonly used in cement processing is milling, which is a mechanical crushing method, that is, the milling tool is inserted and then the pipe column is rotated to grind the cement to achieve the purpose of cleaning the cement.

[0038] Schematically, in some embodiments, a casing milling head for well repair is provided, including a casing milling head body, one end of the casing milling head body is a cutting head, the casing milling head body is a hollow cylinder, the inner wall of the cutting head is an inverted cone hole, the outer side of the upper surface of the cutting head is provided with a first cutting component for cutting well wall rock, and the inverted cone hole of the cutting head is provided with a second cutting component for cutting cement ring, casing external packer and stabilizer.

[0039] Therefore, the cementing cement is mechanically destroyed by the first cutting assembly and the second cutting assembly, and the cementing cement is removed from the environmental space.

[0040] However, if Figure 1 As shown, the cleaning device 100 for cementing cement provided in the embodiment of the present disclosure includes a sand mixing liquid delivery pipe 110 for delivering the sand mixing liquid and a hydraulic cutting cement ring tool 120 .

[0041] Among them, the sand mixing liquid delivery pipe 110 is connected to the hydraulic cutting cement ring tool 120, and the sand mixing liquid delivery pipe 110 is used to deliver the sand mixing liquid to the hydraulic cutting cement ring tool 120, that is, the sand mixing liquid delivery pipe 110 is used to deliver the sand mixing liquid to the hydraulic cutting cement ring tool 120, so that the hydraulic cutting cement ring tool 120 sprays the sand mixing liquid to the location of the cementing cement, cuts the cement consolidated outside the damaged casing, cuts the cement into pieces, and realizes cement crushing and removal.

[0042] In some embodiments, Figure 2 As shown, the hydraulic cutting cement ring tool 120 includes a nozzle base assembly 121 and a nozzle 122. The nozzle 122 is arranged on the bottom surface of the nozzle base assembly 121, that is, the nozzle 122 is arranged on the side of the nozzle base assembly 121 facing the cementing cement.

[0043] The radial thickness of the nozzle base assembly 121 matches the annular space where the cement is located between two layers of completion casing.

[0044] Combined with the structural description of the above cleaning device, the principle of the cleaning device for cementing cement provided in the embodiment of the present disclosure is first introduced:

[0045] The sand-mixing liquid is transported to the hydraulic cement ring cutting tool through the sand-mixing liquid delivery pipe. Since the hydraulic cement ring cutting tool includes a nozzle base assembly and a nozzle, the sand-mixing liquid is divided into each nozzle in the nozzle base assembly and sprayed through the nozzle. After the cleaning device is placed in the annular space between two layers of completion casings, the sand-mixing liquid sprayed from the nozzle cuts the cementing cement and cuts the cementing cement into fragments, thereby realizing a method of crushing the cement and thus removing it.

[0046] In summary, the cement cleaning device provided in the embodiment of the present disclosure provides a sand mixing liquid delivery pipe and a hydraulic cement cutting ring tool, delivers sand mixing liquid to the hydraulic cement cutting ring tool through the sand mixing liquid delivery pipe, and sprays sand mixing liquid to the position where the cementing cement is located through the hydraulic cement cutting ring tool, so as to cut the cementing cement into pieces of different sizes, and cleans the cementing cement by using the sand mixing liquid as an impact to avoid drill sticking, thereby improving the safety and cleaning efficiency in the cementing cement cleaning process and improving the cleaning effect.

[0047] In some embodiments, the above-mentioned two layers of completion casing include a first completion casing 131 and a second completion casing 132. The first completion casing 131 is sleeved on the periphery of the second completion casing 132, and cementing cement is poured between the first completion casing 131 and the second completion casing 132. In some embodiments, the first completion casing 131 is a surface casing, and the second completion casing 132 is an oil layer casing, that is, the second completion casing 132 is used to transport oil and water resources, and the first completion casing 131 is used to be sleeved on the periphery of the second completion casing 132 to protect the second completion casing 132.

[0048] Since it is necessary to ensure that the nozzle base assembly 121 can smoothly enter the annular space between the first completion casing 131 and the second completion casing 132 , it is necessary to ensure that the radial thickness of the nozzle base assembly 121 meets the size limit of the annular space.

[0049] In some embodiments, the radial thickness of the nozzle base assembly 121 is less than half of the radial thickness difference between the first completion casing 131 and the second completion casing 132 , where the radial thickness difference is the difference between the inner diameter of the first completion casing 131 and the outer diameter of the second completion casing 132 .

[0050] That is, the radial thickness difference is obtained by subtracting the outer diameter of the second completion casing 132 from the inner diameter of the first completion casing 131, and the radial thickness of the nozzle base assembly 121 needs to be less than half of the radial thickness difference. The radial thickness of the nozzle base assembly 121 needs to be less than half of the radial thickness difference.

[0051] In some embodiments, the second completion casing 132 includes a coupling pipe section and a deformed pipe section. The coupling pipe section refers to a connecting pipe section used to connect two pipe sections, and the two pipe sections are connected by a coupling; the deformed pipe section refers to a pipe section on the second completion casing 132 that has been deformed, such as: a pipe section on the second completion casing 132 that has a change in outer diameter is a deformed pipe section. Since the deformed pipe section may increase the maximum outer diameter of the second completion casing 132 and the coupling pipe section is usually the area with the largest outer diameter on the second completion casing 132, when the second completion casing 132 includes a coupling pipe section and a deformed pipe section, the following size determination is required:

[0052] First, in response to the outer diameter of the first pipe section being greater than the outer diameter of the second pipe section, the radial thickness difference is the difference between the inner diameter of the completion casing of the first completion casing 131 and the outer diameter of the first pipe section;

[0053] When the outer diameter of the coupling pipe section is greater than the outer diameter of the deformed pipe section, the radial thickness difference is determined by the difference between the inner diameter of the completion casing of the first completion casing 131 and the outer diameter of the coupling pipe section, thereby obtaining a region with the minimum radial thickness difference.

[0054] Schematically, Dsc is used to indicate the inner diameter of the surface casing, Dbc is used to indicate the outer diameter of the oil layer casing coupling, and Dde is used to indicate the outer diameter of the deformation section of the oil layer casing. Then, when Dbc>Dde, W<(Dsc-Dbc) / 2.

[0055] Second, in response to the outer diameter of the first pipe section being less than or equal to the outer diameter of the second pipe section, the radial thickness difference is the difference between the completion casing inner diameter of the first completion casing 131 and the outer diameter of the second pipe section.

[0056] Among them, the outer diameter of the first pipe section is the outer diameter of the coupling pipe section, and the outer diameter of the second pipe section is the outer diameter of the deformed pipe section. That is, when the outer diameter of the coupling pipe section is less than or equal to the outer diameter of the deformed pipe section, the radial thickness difference is determined by the difference between the inner diameter of the completion casing of the first completion casing 131 and the outer diameter of the deformed pipe section, thereby obtaining the area with the smallest radial thickness difference.

[0057] Schematically, Dsc is used to represent the inner diameter of the surface casing, Dbc is used to represent the outer diameter of the oil layer casing coupling, and Dde is used to represent the outer diameter of the deformation section of the oil layer casing. Then, when Dbc≤Dde, W<(Dsc-Dde) / 2.

[0058] In some embodiments, the maximum outer diameter of the sand mixing fluid delivery pipe 110 also needs to be smaller than half of the radial thickness difference, so that the sand mixing fluid delivery pipe 110 can also be normally inserted into the annular space between the first completion casing 131 and the second completion casing 132 .

[0059] In summary, the cement cleaning device provided in the embodiments of the present invention provides a sand mixing liquid delivery pipe and a hydraulic cement cutting ring tool, delivers sand mixing liquid to the hydraulic cement cutting ring tool through the sand mixing liquid delivery pipe, and sprays sand mixing liquid to the position where the cementing cement is located through the hydraulic cement cutting ring tool, so as to cut the cementing cement into fragments, and clean the cementing cement by using the sand mixing liquid as an impact to avoid drill sticking, thereby improving the safety and cleaning efficiency in the cementing cement cleaning process and improving the cleaning effect.

[0060] The device provided in this embodiment limits the radial thickness of the nozzle base assembly according to the size of the annular space between the first completion casing and the second completion casing when determining the radial thickness of the nozzle base assembly, and determines the maximum radial thickness of the nozzle base assembly that can be accommodated in the annular space according to the coupling pipe section and the deformed pipe section on the second completion casing, thereby avoiding the problem of the cleaning device of the cementing cement being stuck in the annular space.

[0061] In some embodiments, the nozzle base assembly 121 is in a circular ring or a crescent shape. When the nozzle base assembly 121 is in a circular ring shape, the nozzle base assembly 121 is a circular ring shape that surrounds the second completion casing 132 in a complete circle, and the nozzle base assembly 121 only needs to move up and down in the annular space between the completion casings, wherein the nozzles 122 are evenly distributed on the circular ring of the nozzle base assembly 121, that is, a nozzle 122 is arranged at a preset distance on the circular ring; when the nozzle base assembly 121 is in a crescent shape, the nozzle base assembly 121 is a base assembly that semi-surrounds the second completion casing 132 in a crescent shape, and the nozzle base assembly 121 needs to move up and down in the annular space between the completion casings, and in some embodiments, the nozzle base assembly 121 also needs to rotate in the annular space between the completion casings, so as to ensure that the cementing cement in the annular space can be fully cleaned.

[0062] Optionally, the hydraulic cutting cement ring tool 120 includes a fixed nozzle and a rotating nozzle, wherein the fixed nozzle is fixed vertically to the nozzle base assembly 121, and the spraying mode of the rotating nozzle changes in rotation during the spraying process of the sand mixing liquid.

[0063] A fixed nozzle refers to a nozzle that is fixed on the nozzle base assembly 121 and has a fixed injection direction. In some embodiments, the injection direction of the fixed nozzle is perpendicular to the nozzle base assembly 121; a rotating nozzle refers to a nozzle that is fixed in position on the nozzle base assembly 121 and has a dynamically changing injection direction, or a rotating nozzle refers to a nozzle that has a constant injection direction for the sand mixing liquid relative to the nozzle itself, but changes direction relative to the nozzle base assembly 121.

[0064] Among them, when the rotating nozzle is fixed on the nozzle base assembly 121, the rotating nozzle is fixed in the slot on the nozzle base assembly 121, and can be rotated in the slot, thereby realizing the rotation of the spraying direction; when the rotating nozzle moves on the nozzle base assembly 121, an annular or semi-annular track is provided on the nozzle base assembly 121, and the nozzle is clamped in the track and moves in the track; or, the nozzle is clamped in the track and moves with the rotation of the track.

[0065] In some embodiments, the nozzle base assembly 121 is traced through the oil layer casing (i.e., the second completion casing mentioned above), and the jet direction of the straightening nozzle 122 is always downward along the oil layer casing. An eccentric liquid inlet is arranged on the plane of the nozzle base assembly 121, and the liquid inlet is connected to the hollow sand mixing liquid delivery pipe. Each nozzle 122 on the nozzle base assembly 121 has a separate liquid inlet channel.

[0066] The sand mixing liquid is obtained by mixing the surface liquid and quartz sand in a preset ratio. In some embodiments, the sand mixing liquid is a sand mixing liquid having a viscosity greater than 70 mPa.s after the quartz sand and the liquid are mixed.

[0067] Schematically, quartz sand and liquid (viscosity greater than 70mPa.s) are pressurized by a high-pressure pumping device, and after passing through a hydraulic cutting cement ring tool, they become high-pressure (pressure greater than 18MPa) and high-speed (flow rate greater than 150m / s) fluids, which cut the cement solidified outside the damaged casing and cut the cement into pieces of different sizes, thereby achieving the crushing and removal of cementing cement.

[0068] Figure 3 is a flow chart of a method for cleaning cement provided by an exemplary embodiment of the present disclosure, such as Figure 3 As shown, the method includes:

[0069] Step 301, controlling a cleaning device for cementing cement to penetrate into an annular space between two layers of completion casings.

[0070] The cleaning device includes a sand mixing liquid delivery pipe and a hydraulic cutting cement ring tool.

[0071] In an optional embodiment, the process of inserting the cleaning device into the annular space is manually controlled by the cleaning personnel, or the insertion process is automatically controlled by a control device; or the insertion process is electrically controlled by the cleaning personnel through a control device, such as: when the cleaning personnel presses a physical button, the cleaning device is inserted at a preset speed, and when the cleaning personnel stops pressing the physical button, the cleaning device is paused from continuing to insert.

[0072] The sand-mixing liquid delivery pipe is used to deliver the sand-mixing liquid to the hydraulic cutting cement ring tool, that is, the sand-mixing liquid delivery pipe is used to deliver the sand-mixing liquid to the hydraulic cutting cement ring tool, so that the hydraulic cutting cement ring tool sprays the sand-mixing liquid to the location of the cementing cement, cuts the cement consolidated outside the damaged casing, cuts the cement into pieces, and realizes cement crushing and removal.

[0073] The two-layer completion casing includes a first completion casing and a second completion casing, an annular space is formed between the first completion casing and the second completion casing, and the cleaning device is inserted into the annular space between the first completion casing and the second completion casing. The first completion casing is a surface casing, and the second completion casing is an oil layer casing.

[0074] In an optional embodiment, an annular hydraulic cutting cement ring tool is connected to a sand mixing fluid delivery pipe and lowered into the annular space between the oil layer casing and the surface casing to a position where cementing cement needs to be cleaned.

[0075] The radial thickness of the nozzle base assembly is less than half of the radial thickness difference between the first completion casing and the second completion casing, wherein the radial thickness difference is the difference between the inner diameter of the first completion casing and the outer diameter of the second completion casing.

[0076] In some embodiments, the second completion casing includes a coupling pipe section and a deformed pipe section, wherein the coupling pipe section refers to a connecting pipe section used to connect two pipe sections, and the two pipe sections are connected by means of a coupling; the deformed pipe section refers to a pipe section on the second completion casing that has been deformed, such as: a pipe section on the second completion casing whose outer diameter has changed is a deformed pipe section.

[0077] First, in response to the outer diameter of the first pipe section being greater than the outer diameter of the second pipe section, the radial thickness difference is the difference between the completion casing inner diameter of the first completion casing and the outer diameter of the first pipe section;

[0078] When the outer diameter of the coupling pipe section is greater than the outer diameter of the deformed pipe section, the radial thickness difference is determined by the difference between the completion casing inner diameter of the first completion casing and the outer diameter of the coupling pipe section, thereby obtaining a region with the minimum radial thickness difference.

[0079] Second, when the outer diameter of the coupling pipe section is less than or equal to the outer diameter of the deformed pipe section, the radial thickness difference is determined by the difference between the inner diameter of the completion casing of the first completion casing and the outer diameter of the deformed pipe section, thereby obtaining a region with the minimum radial thickness difference.

[0080] Step 302: conveying the sand-mixing liquid to the hydraulic cutting cement ring tool through the sand-mixing liquid conveying pipe.

[0081] The hydraulic cutting cement ring tool comprises a nozzle base assembly and a nozzle.

[0082] The radial thickness of the nozzle base assembly is less than half of the radial thickness difference between the first completion casing and the second completion casing, wherein the radial thickness difference is the difference between the inner diameter of the first completion casing and the outer diameter of the second completion casing.

[0083] That is, the radial thickness difference is obtained by subtracting the completion casing outer diameter of the second completion casing from the completion casing inner diameter of the first completion casing, and the radial thickness of the nozzle base assembly needs to be less than half of the radial thickness difference. The radial thickness difference includes the difference in diameter between the completion casing inner diameter of the first completion casing and the completion casing outer diameter of the second completion casing, and includes twice the thickness of the annular space. Therefore, the radial thickness of the nozzle base assembly needs to be less than half of the radial thickness difference.

[0084] Sand mixing liquid is a liquid obtained by mixing a certain sand ratio using a ground sand mixing device.

[0085] Step 303, controlling the nozzle base assembly to a position within a preset distance range from the cementing cement.

[0086] Optionally, when the cementing cement is at a first distance position from the top of the completion casing, the nozzle base assembly is controlled to be lowered to a second distance position from the top of the completion casing, wherein the distance difference between the first distance position and the second distance position is less than a preset distance range.

[0087] Step 304: spray the sand-mixing liquid through the nozzle.

[0088] Optionally, a high-pressure pump is provided on the ground, and the pump is turned on for circulation to inject the sand-mixing liquid into the hydraulic cutting cement ring tool through the sand-mixing liquid delivery pipe, thereby generating a high-speed jet distributed along the annular space to break the cementing cement in the annular space.

[0089] Furthermore, as the fixed cement is broken, the hydraulic cutting cement ring tool is continuously lowered vertically to process the remaining cement.

[0090] Schematically, in a production oil well, the second oil layer casing below the wellhead is damaged and needs to be replaced. The well is completed with two-open casing. The outer diameter of the surface casing is 339.7mm, the inner diameter (Dsc) is 315.3mm, the outer diameter of the oil layer casing is 139.7mm, the outer diameter of the coupling (Dbc) is 156mm, and the oil layer casing is deformed, with the maximum deformed outer diameter (Dde) being 148mm.

[0091] There is cementing cement outside the oil layer casing, and the depth of the cement top surface is 15m.

[0092] An annular nozzle base assembly is provided. Since Dbc>Dde, the radial thickness W of the nozzle base assembly is required to satisfy: W<(Dsc-Dbc) / 2.

[0093] The radial thickness W of the nozzle base assembly is 60 mm.

[0094] There are 6 fixed nozzles, which are vertically downward and evenly distributed in a circle on the lower plane of the nozzle base assembly.

[0095] A liquid inlet is arranged on the upper plane of the nozzle base assembly, the mid-vertical line of the liquid inlet is located on the circumference of the center of each nozzle, and the inner diameter of the liquid inlet is 35 mm.

[0096] The delivery tube is hollow, with an outer diameter of 35 mm and an inner diameter of 25 mm, and is connected to the liquid inlet by a thread.

[0097] The nozzle base assembly is lowered into the cementing position by connecting a plurality of delivery pipes through threads.

[0098] The ground sand mixing device mixes guar gum and quartz sand into a 5% sand mixing liquid with a displacement of 200L / min, which is injected into the nozzle base assembly through the delivery pipe. High-speed water jets are generated through 6 nozzles. The sand particles carried by the water grind the cementing cement and are carried out by the circulating liquid.

[0099] The nozzle base assembly is traced through the oil layer casing, and the jet direction of the straightening nozzle is always vertical. The nozzle base assembly is deepened along the annular space between the oil layer casing and the surface casing, and the cyclic jet is continued after encountering resistance, and so on, the cementing cement outside the oil layer casing is processed vertically.

[0100] Schematically, high-pressure sand-mixed liquid is used to cut cement cement at high speed, including the following steps:

[0101] (1) Use a ground sand mixing device to prepare a sand mixing liquid with a certain sand ratio.

[0102] (2) Connect the annular hydraulic cutting cement ring tool to the delivery pipe and lower it into the annular space between the oil layer casing and the surface casing to the position where the cementing cement needs to be cleaned.

[0103] (3) Start the pump circulation and inject the sand-mixing liquid into the hydraulic cutting cement ring tool through the delivery pipe, generating a high-speed jet distributed along the annular space to break the cement in the annular space.

[0104] (4) Vertically lower the hydraulic cutting tool to handle the remaining cement.

[0105] In summary, the cementing cement cleaning method provided in the embodiments of the present invention provides a sand mixing liquid delivery pipe and a hydraulic cement cutting ring tool, delivers the sand mixing liquid to the hydraulic cement cutting ring tool through the sand mixing liquid delivery pipe, and sprays the sand mixing liquid to the position where the cementing cement is located through the hydraulic cement cutting ring tool to cut the cementing cement into pieces of different sizes, and cleans the cementing cement by using the sand mixing liquid as an impact to avoid drill sticking, thereby improving the safety and cleaning efficiency in the cementing cement cleaning process and improving the cleaning effect.

[0106] The method provided in this embodiment limits the radial thickness of the nozzle base assembly according to the size of the annular space between the first completion casing and the second completion casing when determining the radial thickness of the nozzle base assembly, and determines the maximum radial thickness of the nozzle base assembly that can be accommodated in the annular space according to the coupling pipe section and the deformed pipe section on the second completion casing, thereby avoiding the problem of the cleaning device of the cementing cement being stuck in the annular space.

[0107] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for cleaning cement, characterized in that: The method comprises: A cleaning device for controlling cementing cement is inserted into the annular space between two layers of completion casings, the cleaning device comprising a sand mixing liquid delivery pipe and a hydraulic cement ring cutting tool, the two layers of completion casings comprising a first completion casing and a second completion casing, the first completion casing being sleeved on the periphery of the second completion casing, and an annular space being formed between the first completion casing and the second completion casing and filled with the cementing cement; The sand mixing fluid is conveyed to the hydraulic cutting cement ring tool through the sand mixing fluid conveying pipe, the hydraulic cutting cement ring tool includes a nozzle base assembly and a nozzle, the nozzle base assembly is provided with an annular or semi-annular track, the nozzle is clamped in the annular or semi-annular track and moves with the rotation of the annular or semi-annular track, the nozzle base assembly is traced by the second completion casing, the nozzle jet direction is straightened to be always vertical, and the nozzle base assembly is deepened along the annular space, the sand mixing fluid includes quartz sand, ground liquid and guar gum; Controlling the nozzle base assembly to a position within a preset distance range from the cementing cement; The sand mixing fluid is sprayed through the nozzle, wherein the second completion casing includes a coupling pipe section and a deformed pipe section, in response to the outer diameter of the first pipe section being greater than the outer diameter of the second pipe section, the radial thickness difference of the nozzle base assembly is the difference between the inner diameter of the completion casing of the first completion casing and the outer diameter of the first pipe section; in response to the outer diameter of the first pipe section being less than or equal to the outer diameter of the second pipe section, the radial thickness difference is the difference between the inner diameter of the completion casing of the first completion casing and the outer diameter of the second pipe section, the outer diameter of the first pipe section is the outer diameter of the coupling pipe section, and the outer diameter of the second pipe section is the outer diameter of the deformed pipe section.

2. A cleaning device for cementing, characterized in that: The cleaning device comprises: a sand mixing liquid delivery pipe for delivering the sand mixing liquid and a hydraulic cement ring cutting tool; The sand mixing liquid delivery pipe is in communication with the hydraulic cement cutting tool, and the sand mixing liquid delivery pipe is used to deliver the sand mixing liquid to the hydraulic cement cutting tool; The hydraulic cutting cement ring tool comprises a nozzle base assembly and a nozzle, wherein the radial thickness of the nozzle base assembly matches the annular space where the cementing cement is located between two layers of completion casings; The two layers of completion casings include a first completion casing and a second completion casing, the first completion casing is sleeved on the periphery of the second completion casing, and an annular space is formed between the first completion casing and the second completion casing, and the cementing cement is poured therein; The second completion casing includes a coupling pipe section and a deformed pipe section. In response to the outer diameter of the first pipe section being greater than the outer diameter of the second pipe section, the radial thickness difference of the nozzle base assembly is the difference between the inner diameter of the completion casing of the first completion casing and the outer diameter of the first pipe section. In response to the outer diameter of the first pipe section being less than or equal to the outer diameter of the second pipe section, the radial thickness difference is the difference between the inner diameter of the completion casing of the first completion casing and the outer diameter of the second pipe section, the outer diameter of the first pipe section is the outer diameter of the coupling pipe section, and the outer diameter of the second pipe section is the outer diameter of the deformed pipe section. The nozzle is arranged on the bottom surface of the nozzle base assembly, and an annular or semi-annular track is arranged on the nozzle base assembly. The nozzle is clamped in the annular or semi-annular track and moves with the rotation of the annular or semi-annular track. The nozzle base assembly is traced by the second completion casing to straighten the nozzle so that the jet direction is always vertical, and the nozzle base assembly is deepened along the annular space. The sand mixing fluid includes quartz sand, ground liquid and guar gum.

3. The device according to claim 2, characterized in that The first completion casing is a surface casing; The second completion casing is an oil layer casing.

4. The cleaning device according to claim 2, characterized in that: The hydraulic cement ring cutting tool comprises a fixed nozzle and a rotating nozzle; The fixed nozzle is fixed vertically to the nozzle base assembly; The spraying direction of the rotary nozzle changes in rotation during the spraying process of the sand mixing liquid.

5. The cleaning device according to claim 2, characterized in that: The nozzle base assembly is in a circular ring shape or a crescent shape.

6. The cleaning device according to claim 2, characterized in that: The sand mixing liquid is obtained by mixing ground liquid and quartz sand in a preset ratio.

7. The cleaning device according to claim 2, characterized in that: An eccentric liquid inlet is provided on the upper plane of the nozzle base assembly, and the liquid inlet is connected to the hollow sand mixing liquid delivery pipe; Each nozzle on the nozzle base assembly has a separate liquid inlet channel.

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