Method of cementing, cementing pipe string, and cementing apparatus

Abstract

The application provides a method for supplementing cement slurry for a cementing void section, a cement slurry supplementing pipe string and a cement slurry supplementing device. The cement slurry supplementing pipe string comprises a packer, and a perforating device connected with the bottom of the packer and in communication with the packer. The perforating device determines the position of the cementing void section by perforating in the casing, and the perforating device cooperates with the packer to supplement cement slurry for the cementing void section. According to the technical scheme of the application, the cementing void section is accurately found by the perforating device, and the cementing void section is quickly filled with cement slurry by cooperation of the perforating device and the packer, thereby avoiding the problems of poor cementing quality and low cementing operation efficiency of the cementing void section caused by the cement supplementing process and equipment in the related art, and improving the cementing quality and the cementing operation efficiency of the cementing void section.

Description

Technical Field

[0001] This invention relates to the field of equipment for replenishing cement slurry in the cementing displacement section, and particularly to a method for replenishing cement slurry in the cementing displacement section, a cement slurry replenishment pipe string, and a cement slurry replenishment device. Background Technology

[0002] As my country's oil and gas resource development accelerates, oil and gas wells are becoming increasingly deeper vertically and longer horizontally. The quality of cementing directly affects the smooth execution of subsequent processes such as fracturing. However, issues like premature opening of the toe sleeve or failure of the cement plug can lead to runoff accidents during cementing operations. This results in the annulus at the end of the well section being unfilled with cement slurry, affecting subsequent drilling, testing, and completion operations, and in severe cases, even causing the well to be scrapped, resulting in significant economic losses.

[0003] In related technologies, cementing slurry injection into the cementing displacement section is typically completed using bare drill pipe cementing and bridge plug cementing processes. However, this process and related equipment are difficult to implement, take a long time, and make it difficult to guarantee the cementing quality and operational efficiency of the cementing displacement section.

[0004] In other words, the cement filling process and equipment in related technologies can easily lead to poor cementing quality and low operational efficiency in the cementing replacement section. Summary of the Invention

[0005] To address the problems in the prior art, this application proposes a method, a cement slurry injection string, and a cement slurry injection device for injecting cement slurry into the cementing displacement section, which solves the problem that the cementing process and equipment in the related technologies easily lead to poor cementing quality and low operating efficiency in the cementing displacement section.

[0006] The present invention relates to a cement slurry injection string, a method for injecting cement slurry, and a cement slurry injection device for cementing displacement sections.

[0007] One aspect of this invention provides a method for injecting cement slurry, comprising: step S1, assembling a cement slurry injection pipe string; step S2, connecting the assembled cement slurry injection pipe string to an upper feed pipe string; step S3, lowering the cement slurry injection pipe string to the bottom of the well and circulating and flushing the well; step S4, performing perforation on the inner wall of the casing until the location of the cementing displacement section is determined; step S5, injecting cement slurry into the cementing displacement section; step S6, disconnecting the cement slurry injection pipe string from the upper feed pipe string; and step S7, raising the upper feed pipe string and pressurizing it for solidification.

[0008] In one embodiment, before step S3, the method further includes: step S1, assembling the cement grout injection pipe string; and step S2, connecting the assembled cement grout injection pipe string to the upper feed pipe string. Through this embodiment, the perforating device and the packer can be correctly connected to complete the connection between the cement grout injection pipe string and the upper feed pipe string, thereby ensuring that the cement grout injection pipe string can subsequently operate normally.

[0009] In one embodiment, step S4 includes: step S401, determining the lower hole perforation position based on logging data; step S402, lowering the perforation device of the cement slurry injection string to the lower hole perforation position; step S403, pumping in abrasive to perform hydraulic blasting perforation to form the lower hole perforation; step S404, determining the upper hole perforation position based on logging data; step S405, raising the perforation device to the upper hole perforation position; step S406, pumping in abrasive to perform hydraulic blasting perforation to form the upper hole perforation; step S407, checking whether the lower hole perforation and the upper hole perforation are connected; if yes, proceeding to step S5; if no, repeating steps S404 to S406 until the lower hole perforation and the upper hole perforation are connected. In this implementation method, the upper perforations are sequentially ejected from the farthest point towards the lower perforation until they connect with each other. This means the perforation locations of the lower and upper perforations are situated within the cementing displacement section, facilitating subsequent cement slurry injection. This ensures the smooth execution of subsequent injection operations.

[0010] In one embodiment, the method for determining whether the lower perforation and the upper perforation are connected includes: pumping fluid into the wellhead; checking for pressure buildup at the wellhead; if yes, the lower perforation and the upper perforation are connected; if no, the lower perforation and the upper perforation are not connected. This embodiment indirectly determines whether the lower perforation and the upper perforation are connected by judging whether there is pressure buildup at the wellhead. This indirect determination method avoids the difficulty of directly determining whether the lower perforation and the upper perforation are connected. Therefore, it can accurately determine whether the lower perforation and the upper perforation are connected.

[0011] In one embodiment, step S5 includes: step S501, adjusting the lowering position of the cement slurry injection pipe string to ensure it is between the lower perforation and the upper perforation connected to the lower perforation; step S502, setting the packer of the cement slurry injection pipe string and cleaning the cementing displacement section; step S503, opening the packer and cleaning the wellbore; and step S504, pumping cement slurry until the designed volume is reached. Through this embodiment, the perforation device and packer working together can achieve cement slurry injection into the cementing displacement section, thus meeting the field requirements for cement slurry injection into the cementing displacement section.

[0012] In one embodiment, step S6 includes: step S601, inserting a small ball from the top of the upper feed string; step S602, pumping displacement fluid until the small ball reaches the position of the packer in the cement slurry injection string; step S603, starting to pressurize the packer; step S604, continuing to pressurize until the packer's shear pin breaks. Through this embodiment, the cement slurry injection string can be smoothly separated from the upper feed string, leaving the packer and perforation device at the bottom of the well, thereby facilitating the replacement of upper feed strings with other functions and ensuring that subsequent downhole operations can be carried out normally.

[0013] Another method of the present invention provides a cement slurry injection string, which is used in conjunction with the above-mentioned cement slurry injection method, including: a packer; a perforation device connected to the bottom of the packer and communicating with the packer; wherein, the perforation device determines the position of the cementing displacement section by perforating inside the casing, and the perforation device works in conjunction with the packer to inject cement slurry into the cementing displacement section.

[0014] In one embodiment, the perforation device includes a water jet gun.

[0015] In one embodiment, the packer has a one-way flow function to prevent cement slurry from flowing back into the replenishment cement slurry string. This embodiment ensures that the replenishment cement slurry in the cementing displacement section can be pressurized and allowed to solidify, thereby improving the cementing quality of the displacement section and meeting its cementing requirements.

[0016] Another aspect of the present invention provides a cement injection device, comprising: a cement injection slurry string for cementing displacement section as described above; and an upper feed string connected to the top end of the cement injection slurry string.

[0017] The above-mentioned technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0018] The present invention provides a method, a cement slurry injection string, and a cement slurry injection device for injecting cement slurry into the cementing displacement section, which, compared with the prior art, have at least the following advantages:

[0019] (1) This application accurately locates the cementing displacement section through the perforation device. By working in conjunction with the perforation device and packer, the cementing displacement section can be quickly filled with cement slurry. This avoids the problem of poor cementing quality and low cementing efficiency in the cementing displacement section caused by the cementing process and equipment used in related technologies. This improves the cementing quality and cementing efficiency of the cementing displacement section.

[0020] (2) The cement slurry injection string combines the perforation device and packer in the manner described above and operates in conjunction with them according to the construction process. This gives the cement slurry injection string the dual functions of perforation and cement injection. Thus, the next run of the tubing can complete multiple operations (including perforation, pressure testing, well washing, and cement slurry injection), thereby significantly saving downhole operation time and improving the efficiency of the operation. Attached Figure Description

[0021] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0022] Figure 1 This shows a schematic diagram of the structure of a cement grouting string for cementing displacement section according to Embodiment 1 of the present invention;

[0023] Figure 2 This shows a schematic diagram of the structure of a second embodiment of the cement grouting string for cementing displacement sections according to the present invention;

[0024] Figure 3 This shows a flowchart of the cement slurry injection method for a cement slurry injection string for a cementing displacement section according to Embodiment 3 of the present invention;

[0025] Figure 4 Showing Figure 3 The flowchart of the specific method for step S4 in the process;

[0026] Figure 5 Showing Figure 3 The flowchart of the specific method for step S5 in the process;

[0027] Figure 6 Showing Figure 3 The flowchart of the specific method for step S6 in the process.

[0028] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0029] Figure label:

[0030] 10. Packer; 20. Perforation device; 30. Casing; 40. Cementing displacement section; 50. Lower hole perforation; 60. Upper hole perforation. Detailed Implementation

[0031] The invention will now be further described with reference to the accompanying drawings.

[0032] It should be noted that the cement slurry injection method, cement slurry injection pipe string, and cement slurry injection device in this application are applied after cementing operations and before perforation testing operations.

[0033] The cement slurry injection string in this application is used to inject cement slurry into the cementing displacement section 40 formed during cementing operations, followed by perforation testing. The top of the cement slurry injection string is connected to the upper feed string, and its position downhole can be adjusted by raising or lowering the feed string. The upper feed string in this application can be tubing, drill pipe, or coiled tubing, but is not limited to these; other types of feed strings are also possible.

[0034] like Figure 1 As shown, the present invention provides a cement slurry injection string for a cementing displacement section 40, including a packer 10 and a perforation device 20. The perforation device 20 is connected to and communicates with the bottom of the packer 10. The perforation device 20 determines the position of the cementing displacement section 40 by perforating within the casing 30. The perforation device 20 works in conjunction with the packer 10 to inject cement slurry into the cementing displacement section 40.

[0035] It should be noted that in this application, a perforation device 20 is used to perforate at the bottom of the well to form a lower perforation 50, and a perforation is made at a position closer to the wellhead than the lower perforation 50 to form an upper perforation 60. If the lower perforation 50 and the upper perforation 60 are connected, it proves that the cementing displacement section 40 has been found. Thus, the specific location of the cementing displacement section 40 is determined by perforation, thereby ensuring that cement slurry can be injected into the cementing displacement section 40 subsequently. At this time, the lower perforation 50 serves as the inlet for cement slurry injection, and the upper perforation 60 serves as the outlet for cement slurry injection. The packer 10 is set between the upper perforation 60 and the lower perforation 50 to isolate the annular space formed between the casing 30 and the cement slurry injection string that connects the upper perforation 60 and the lower perforation 50. Then, cement slurry is injected into the cementing displacement section 40 through the perforation device 20 via the lower perforation 50. After the cement slurry fills the cementing displacement section 40, it returns through the upper perforation 60 and finally exits the wellhead. Thus, by working in conjunction with the packer 10, the perforation device 20 achieves the function of injecting cement slurry into the cementing displacement section 40, thereby improving the cementing quality of the cementing displacement section 40.

[0036] In the above setup, the cement slurry injection string accurately locates the cementing displacement section 40 through the perforation device 20. By working in conjunction with the perforation device 20 and the packer 10, the cementing displacement section 40 can be quickly filled with cement slurry. This avoids the problem of poor cementing quality and low cementing efficiency in the cementing displacement section 40 caused by the cementing process and equipment used in related technologies, thereby improving the cementing quality and cementing efficiency of the cementing displacement section 40.

[0037] Furthermore, the cement slurry injection string combines the perforation device 20 and the packer 10 in the manner described above, and operates in conjunction with the construction process. This gives the cement slurry injection string the dual functions of perforation and cement injection. Thus, a single run of the tubing can complete multiple operations (including perforation, pressure testing, well flushing, and cement slurry injection), significantly saving downhole operation time and improving operational efficiency.

[0038] Specifically, such as Figure 1 As shown, in one embodiment, the perforating device 20 sequentially perforates the casing 30 and the cementing displacement section 40. The perforating device 20 perforates an upper perforation 60 and a lower perforation 50 within the casing 30. There are multiple upper perforations 60 and lower perforations 50, all spaced apart circumferentially along the casing 30. The specific diameter and number of upper perforations 60 and lower perforations 50 need to be designed based on the logging data of the specific well section.

[0039] Example 1

[0040] like Figure 1 As shown, this invention provides a cement slurry injection string for the cementing displacement section 40 of a horizontal well, including a packer 10 and a hydraulic spray gun. The hydraulic spray gun is threadedly connected to the bottom of the packer 10 and communicates with it. The hydraulic spray gun locates the cementing displacement section 40 by perforating within the casing 30. The hydraulic spray gun and packer 10 work together to inject cement slurry into the cementing displacement section 40. The hydraulic spray gun performs hydraulic perforation, and the combined operation of the hydraulic spray gun and packer 10 achieves the cement slurry injection operation, completing the cement slurry injection operation into the cementing displacement section 40.

[0041] In this embodiment, a hydraulic spray gun is used to perforate in the horizontal well section. Specifically, a perforation is made at the bottom of the well to form a lower perforation 50, and a perforation is made to the left of the lower perforation 50 to form an upper perforation 60. If the lower perforation 50 and the upper perforation 60 are connected, it proves that the cementing displacement section 40 has been found. The lower perforation 50 serves as the inlet for cement slurry injection, and the upper perforation 60 serves as the outlet for cement slurry injection. The packer 10 is set between the upper perforation 60 and the lower perforation 50. Cement slurry is then injected into the cementing displacement section 40 from the lower perforation 50 using a hydraulic spray gun. After the cement slurry fills the cementing displacement section 40, it returns from the upper perforation 60 and enters the annulus between the cement slurry injection tubing string and the casing 30, and finally returns to the wellhead.

[0042] Specifically, such as Figure 1 As shown, in Embodiment 1, the packer 10 has a one-way conduction function to prevent cement slurry from flowing back into the cement slurry replenishment string. This ensures that the replenishment cement slurry in the cementing displacement section 40 can be pressurized and solidified, thereby improving the cementing quality of the cementing displacement section 40 and meeting the cementing requirements of the cementing displacement section 40.

[0043] Specifically, such as Figure 1 As shown, in Embodiment 1, a one-way valve may be integrated into the packer 10. The direction of the one-way valve is set to allow fluid to be injected into the well from the wellhead and not to allow the fluid to flow in the reverse direction.

[0044] It should be noted that the cement slurry injected into the cementing displacement section 40 may flow back into the cement slurry injection pipe string under its own gravity, which may easily lead to the problem of incomplete filling in the cementing displacement section 40, thus affecting the cementing quality of the cementing displacement section 40. Therefore, the installation of a one-way valve can avoid this problem.

[0045] Example 2

[0046] like Figure 2 As shown, this invention provides a cement slurry injection string for the cementing displacement section 40 of a vertical well, including a packer 10 and a hydraulic spray gun. The hydraulic spray gun is threadedly connected to the bottom of the packer 10 and communicates with it. The hydraulic spray gun locates the cementing displacement section 40 by perforating within the casing 30. The hydraulic spray gun and packer 10 work together to inject cement slurry into the cementing displacement section 40. The hydraulic spray gun performs hydraulic sandblasting perforation, and the combined operation of the hydraulic spray gun and packer 10 achieves the cement slurry injection operation, completing the cement slurry injection operation into the cementing displacement section 40.

[0047] In this embodiment, a hydraulic spray gun is used to perforate at the bottom of the well to form a lower perforation 50, and a perforation is made above the lower perforation 50 to form an upper perforation 60. If the lower perforation 50 and the upper perforation 60 are connected, it proves that the cementing displacement section 40 has been found. The lower perforation 50 serves as the inlet for cement slurry injection, and the upper perforation 60 serves as the outlet for cement slurry injection. The packer 10 is set between the upper perforation 60 and the lower perforation 50. Cement slurry is then injected into the cementing displacement section 40 from the lower perforation 50 using a hydraulic spray gun. After the cement slurry fills the cementing displacement section 40, it returns from the upper perforation 60 and enters the annulus between the cement slurry injection tubing and the casing 30, and finally returns to the wellhead.

[0048] Specifically, such as Figure 2 As shown, in Embodiment 2, the packer 10 has a one-way conduction function to prevent cement slurry from flowing back into the cement slurry replenishment pipe string.

[0049] Specifically, such as Figure 2 As shown, in Embodiment 2, a one-way valve may be integrated into the packer 10. The direction of the one-way valve is set to allow fluid to be injected into the well from the wellhead only.

[0050] It should be noted that the cement slurry injected into the cementing displacement section 40 may flow back into the cement slurry injection pipe string under its own gravity, which may easily lead to the problem of insufficient filling in the cementing displacement section 40, thus affecting the cementing quality of the cementing displacement section 40.

[0051] Example 3

[0052] like Figure 3 As shown, this application also provides a method for injecting cement grout, which can use the cement grout injection string for the cementing displacement section as described in Example 1 or Example 2. Specifically, it includes the following steps:

[0053] Step S1: Complete the assembly of the cement grout injection pipe string;

[0054] Step S2: Connect the assembled cement grout injection pipe string to the upper feed pipe string;

[0055] Step S3: Lower the cement grout injection pipe string to the bottom of the well and circulate it to flush the well;

[0056] Step S4: Perform perforation on the inner wall of the casing until the location of the cementing displacement section is determined;

[0057] Step S5: Inject cement slurry into the cementing displacement section;

[0058] Step S6: Disconnect the cement grout injection pipe string from the upper feed pipe string;

[0059] Step S7: Lift the upper part of the feed pipe string and pressurize it until it solidifies.

[0060] It should be noted that in this application, the perforation operation, pressure testing operation, well washing, and cement slurry injection operation can be completed in one run of tubing, thereby significantly saving downhole operation time and improving operation efficiency. In addition, this method can accurately locate the cementing displacement section 40, and by working in conjunction with the perforation device 20 and the packer 10, the cementing displacement section 40 can be quickly filled with cement slurry, thereby improving the cementing quality and cementing operation efficiency of the cementing displacement section 40.

[0061] Specifically, in Embodiment 3, step S1 includes:

[0062] Step S101: Move the perforation device to the bottom of the packer;

[0063] Step S102: Fix the perforation device to the bottom of the packer.

[0064] According to the above steps, the perforation device 20 and the packer 10 can be properly connected together, thereby ensuring that the subsequent cement grouting pipe string can work normally.

[0065] Specifically, such as Figure 4As shown, in Embodiment 3, step S4 includes:

[0066] Step S401: Determine the perforation location based on the logging data;

[0067] Step S402: Lower the perforation device of the cement grout injection pipe string to the lower hole perforation position;

[0068] Step S403: Pump in abrasive and perform water jet blasting to form a lower hole.

[0069] Step S404: Determine the perforation location of the upper hole based on the logging data;

[0070] Step S405: Raise the perforation device to the upper perforation position;

[0071] Step S406: Pump in abrasive and perform water jet blasting to form an upper hole.

[0072] Step S407: Whether the lower perforation hole and the upper perforation hole are connected;

[0073] If so, proceed to step S5;

[0074] If not, then repeat steps S404 to S406 until the lower hole and the upper hole are connected.

[0075] According to the above steps, the upper perforations 60 are sequentially injected from far to near the lower perforation 50 until the lower perforation 50 and the upper perforation 60 are connected. That is, the perforation positions of the lower perforation 50 and the upper perforation 60 are located on the cementing displacement section 40. In this way, the cementing displacement section 40 is found, which facilitates the subsequent injection of cement slurry into it. This ensures that the subsequent injection operation can be carried out smoothly.

[0076] Specifically, in Embodiment 3, the method for determining whether the lower perforation and the upper perforation are connected includes:

[0077] Fluid is pumped in from the wellhead;

[0078] Is there pressure buildup at the wellhead?

[0079] If so, the lower perforation hole is connected to the upper perforation hole;

[0080] If not, the lower perforation hole and the upper perforation hole are not connected.

[0081] Based on the above steps, the connection between the lower perforation 50 and the upper perforation 60 is indirectly determined by assessing whether there is pressure buildup at the wellhead. This indirect method avoids the difficulty of directly determining the connection between the lower perforation 50 and the upper perforation 60, thus enabling accurate determination of their connectivity.

[0082] It should be noted that the method for determining whether the lower perforation 50 and the upper perforation 60 are connected is not limited to the indirect determination method in this embodiment; other methods can also be used. For example, a sensor can be installed downhole, and the determination can be made based on the sensor's feedback information.

[0083] Specifically, such as Figure 5 As shown, in Embodiment 3, step S5 includes:

[0084] Step S501: Adjust the lowering position of the cement grout injection pipe string to ensure that it is between the lower perforation hole and the upper perforation hole connected to the lower perforation hole.

[0085] Step S502: Set the packer of the cement grout injection string and clean the cementing displacement section;

[0086] Step S503: Open the packer and clean the wellbore;

[0087] Step S504: Pump in cement slurry until the designed volume is reached.

[0088] According to the above steps, the perforation device 20, in conjunction with the packer 10, can inject cement slurry into the cementing displacement section 40, thereby meeting the on-site requirements for injecting cement slurry into the cementing displacement section 40.

[0089] It should be noted that displacement fluid needs to be injected before the cement slurry is pumped in. This ensures better cementing quality in the 40-section cementing displacement section.

[0090] Specifically, such as Figure 6 As shown, in Embodiment 3, step S6 includes:

[0091] Step S601: Insert a small ball from the top of the upper feed tube string;

[0092] Step S602: Pump in displacement fluid until the ball reaches the position of the packer in the cement grouting string;

[0093] Step S603: Begin pressurizing the packer;

[0094] Step S604: Continue pressurizing until the packer's shear pins break.

[0095] According to the above steps, the cement grout injection pipe string can be smoothly separated from the upper feed pipe string, leaving the packer 10 and the perforation device 20 at the bottom of the well, thereby facilitating the replacement of the upper pipe string with other functions, and ensuring that subsequent downhole operations can be carried out normally.

[0096] It should be noted that the packer 10 in this application can be released by lifting the tubing string and set by pressing the tubing string down. The packer 10 is released from the upper feed tubing string by throwing a ball. At the same time, the packer 10 also has the function of a one-way valve to ensure that cement slurry backflow does not occur after release.

[0097] Example 4

[0098] The present invention also provides a cement injection device, comprising a cement slurry injection pipe string and an upper feed pipe string. The upper feed pipe string is connected to the top end of the cement slurry injection pipe string.

[0099] Specifically, in Embodiment 4, the cement grout injection string includes a packer 10 and a perforation device 20. The perforation device 20 is connected to and communicates with the bottom of the packer 10. The perforation device 20 sequentially perforates the casing 30 and the cementing displacement section 40.

[0100] Specifically, in Embodiment 4, the perforation device 20 perforates an upper perforation 60 and a lower perforation 50 on the inner wall of the sleeve. There are multiple upper perforations 60 and lower perforations 50, all spaced apart circumferentially along the sleeve 30.

[0101] Specifically, in embodiment four, the perforation device 20 is a water jet gun. Of course, the perforation device 20 is not limited to a water jet gun and can also be other types of perforation devices.

[0102] Specifically, in embodiment four, a one-way valve is integrated inside the packer 10, and the direction of the one-way valve is set to allow fluid to be injected into the well from the wellhead only.

[0103] Specifically, in Example 4, the upper feed string is made of tubing, drill pipe, or coiled tubing.

[0104] Specifically, in Embodiment 4, the cementing replenishment device can be applied to the cementing displacement section 40 of a vertical well, or to the cementing displacement section 40 of a horizontal well. Furthermore, the cementing replenishment device can also be applied to the deviated well section.

[0105] Example 5

[0106] The present invention also provides a cement replenishment method, which employs the cement replenishment device described in Example 4. It includes:

[0107] Step 1: Complete the assembly of the cement grout injection pipe string;

[0108] Step one specifically includes:

[0109] The first step is to move the water jet gun to the bottom of the packer;

[0110] The second step is to securely connect the water jet gun to the bottom thread of the packer.

[0111] Step 2: Connect the assembled cement grouting pipe string to the continuous tubing;

[0112] Step 3: Lower the cement grout injection pipe string to the bottom of the well and circulate it to flush the well;

[0113] Step 4: Perform perforation operations on the inner wall of the casing until the location of the cementing displacement section is determined;

[0114] Step four specifically includes:

[0115] The first step is to determine the location of the perforation in the downhole based on the logging data;

[0116] The second step is to lower the hydraulic spray gun of the cement grout injection pipe string to the position of the lower hole injection hole;

[0117] The third step is to pump in abrasive and perform water jet blasting to create a lower hole.

[0118] The fourth step is to determine the perforation location of the upper hole based on the logging data;

[0119] Fifth step, raise the water jet gun to the upper nozzle position;

[0120] Step 6: Pump in abrasive and perform water jet blasting to create upper hole perforations;

[0121] Step 7: Check if the lower perforation hole and the upper perforation hole are connected;

[0122] If so, proceed to step S5;

[0123] If not, then repeat steps S404 to S406 until the lower hole and the upper hole are connected.

[0124] It should be noted that the method to verify whether the lower perforation 50 and the upper perforation 60 are connected is to pump fluid into the wellhead and then pressurize the wellhead. If the pressurization is successful, it means that the two are connected; if the pressurization is unsuccessful, it means that the two are not connected.

[0125] Step 5: Inject cement slurry into the cementing displacement section;

[0126] Step five specifically includes:

[0127] The first step is to adjust the lowering position of the cement grouting pipe string to ensure that it is between the lower perforation hole and the upper perforation hole connected to the lower perforation hole;

[0128] The second step is to set the packer of the cement grout injection string and clean the cementing displacement section.

[0129] The third step is to open the packer and clean the wellbore.

[0130] The fourth step is to pump in cement slurry until the designed volume is reached.

[0131] Step 6: Disconnect the cement grout injection pipe string from the coiled tubing;

[0132] Step six specifically includes:

[0133] The first step is to drop a small ball from the top of the coiled tubing;

[0134] The second step is to pump in the displacement fluid until the small ball reaches the position of the packer of the cement grouting string.

[0135] The third step is to begin pressurizing the packer;

[0136] Fourth, continue pressurizing until the packer's shear pins break.

[0137] Fifth step: Raise the coiled tubing and pressurize it until it solidifies.

[0138] It should be noted that the construction techniques employed in related technologies result in severe pressure build-up in the horizontal sections of the wellbore, leading to high construction risks when tools such as bridge plugs are run into highly deviated or horizontal sections, making it difficult to ensure smooth operation. Furthermore, using small-sized bridge plugs for cement injection can easily cause problems such as difficulty in retrieving the tubing string, potentially leading to secondary accidents. However, using the device and process method described in this application for downhole operations significantly reduces the construction risks when the tubing string is run into highly deviated or horizontal sections, ensuring smooth operation. Moreover, the cement slurry injection tubing string can easily uncouple and disengage from the upper-feed tubing string, allowing the tubing string to be smoothly retrieved from the wellbore, reducing the probability of downhole accidents.

[0139] It should be noted that the technical solution of this invention mainly addresses, but is not limited to, situations where a large section of the annulus is missing cement slurry after cementing a long horizontal section of well. This application employs a special packer and hydraulic spray gun string combination to achieve simultaneous perforation and cementing, significantly improving operational efficiency and shortening operation time. The core of this application lies in the design and implementation of a special functional packer structure. This application offers significant advantages in remedial operations after cementing a long horizontal section of well.

[0140] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects: the cement slurry injection string accurately locates the cementing displacement section through the perforation device, and the cementing displacement section can be quickly filled with cement slurry through the cooperation of the perforation device and the packer. This avoids the problems of poor cementing quality and low cementing efficiency in the cementing displacement section caused by the cementing displacement process and equipment in related technologies, thereby improving the cementing quality and cementing efficiency of the cementing displacement section. In addition, the cement slurry injection string combines the perforation device and the packer in the above manner and cooperates with them according to the construction process. This gives the cement slurry injection string the dual functions of perforation and cementing displacement. Thus, multiple operations (including perforation, pressure testing, well washing, and cement slurry injection) can be completed in the next run of the tubing string, thereby significantly saving downhole operation time and improving the efficiency of the operation.

[0141] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0142] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A method of supplementing a cement slurry, characterized in that, include: Packer; A perforation device is connected to the bottom of the packer and communicates with the packer; The perforation device determines the location of the cementing displacement section by perforating inside the casing. The perforation device works in conjunction with the packer to inject cement slurry into the cementing displacement section. It also includes the following steps: Step S3: Lower the cement grout injection pipe string to the bottom of the well and circulate it to flush the well; Step S4: Perform perforation on the inner wall of the casing until the location of the cementing displacement section is determined; Step S5: Inject cement slurry into the cementing displacement section; Step S6: Disconnect the cement grout injection pipe string from the upper feed pipe string; Step S7: Lift the upper part of the feeding pipe string and pressurize it until it solidifies; Step S4 includes: Step S401: Determine the perforation location based on the logging data; Step S402: Lower the perforation device of the cement grout injection pipe string to the lower hole perforation position; Step S403: Pump in abrasive and perform water jet blasting to form a lower hole. Step S404: Determine the perforation location of the upper hole based on the logging data; Step S405: Raise the perforation device to the upper perforation position; Step S406: Pump in abrasive and perform water jet blasting to form an upper hole. Step S407: Whether the lower perforation and the upper perforation are connected; If so, proceed to step S5; If not, then repeat steps S404 to S406 until the lower hole perforation is connected to the upper hole perforation. The method for determining whether the lower perforation hole and the upper perforation hole are connected includes: Fluid is pumped in from the wellhead; Is the wellhead pressurized? If so, the lower perforation hole is connected to the upper perforation hole; If not, then the lower perforation hole and the upper perforation hole are not connected.

2. The method for injecting cement grout according to claim 1, characterized in that, Prior to step S3, the method further includes: Step S1: Complete the assembly of the cement grout injection pipe string; Step S2: Connect the assembled cement grout injection pipe string to the upper feed pipe string.

3. The method for injecting cement grout according to claim 1, characterized in that, Step S5 includes: Step S501: Adjust the lowering position of the cement grout injection pipe string to ensure that it is between the lower perforation hole and the upper perforation hole connected to the lower perforation hole; Step S502: Set the packer of the cement grout injection string and clean the cementing displacement section; Step S503: Open the packer and clean the wellbore; Step S504: Pump in cement slurry until the designed volume is reached.

4. The method for injecting cement grout according to claim 1, characterized in that, Step S6 includes: Step S601: Insert a small ball from the top of the upper feed tube string; Step S602: Pump in displacement fluid until the ball reaches the position of the packer of the cement grouting string; Step S603: Begin pressurizing the packer; Step S604: Continue to pressurize until the packer's shear pin breaks.

5. The method for injecting cement grout according to claim 1, characterized in that, The perforation device includes a water jet gun.

6. The method for injecting cement grout according to claim 1, characterized in that, The packer has a one-way flow function to prevent the cement slurry from flowing back into the cement slurry replenishment pipe string.

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