A bottom fill tool, string structure and fill method

Abstract

The application relates to the technical field of oil exploitation, in particular to a bottom filling tool, a pipe column structure and a filling method. The bottom filling tool comprises an upper joint assembly, an assembling sleeve, a wireless control assembly and a pressure control assembly. One end of the assembling sleeve is connected with the upper joint assembly, the assembling sleeve and the upper joint assembly are coaxially arranged, and the other end of the assembling sleeve is provided with a switch valve used for closing or opening the hollow cavity. The wireless control assembly is arranged in the assembling sleeve and is in communication connection with the switch valve. When the wireless control assembly receives a switch signal, the switch valve can be controlled to be opened or closed. The pressure control assembly is arranged in the assembling sleeve and is in electric connection with the switch valve. The application can reduce the labor intensity of workers and the construction difficulty.

Description

Technical Field

[0001] This invention relates to the field of oil extraction technology, and in particular to a bottom filling tool, tubing structure, and filling method. Background Technology

[0002] In fracturing and sand control construction, the bottom filling tool is an important supporting tool in oil extraction. Through the bottom filling tool, sand particles can be filled into the predetermined oil layer to form a fracturing fracture with high conductivity. This can increase the permeability of the oil layer, reduce the oil flow resistance, and improve the recovery rate. At present, there are several ways to realize the downhole filling operation with the bottom filling tool: (1) After inserting the bottom filling tool into the sand control tubing through the filling sleeve, the sleeve opens to carry out the filling operation. After completion, the bottom filling tool is pulled out and the sleeve closes; (2) The tubing is inserted into the bottom filling tool. After filling, the tubing is pulled out by raising the high-pressure wellhead. The bottom filling tool is sealed by the float ball to prevent sand particles from entering the bottom filling tool from the reverse direction. However, the main disadvantages of this design are:

[0003] 1) The process is complex and has a low degree of automation, requiring actions such as throwing balls and inserting tubes;

[0004] 2) It requires supporting design tools to carry out filling construction, which is expensive and not easy to promote;

[0005] 3) Construction workers have a heavy workload and are prone to making mistakes;

[0006] 4) During construction, the pump pressure is high, there are many high-pressure devices at the wellhead, and frequent movement of tools can easily cause danger.

[0007] Therefore, a bottom filling tool, tubular structure, and filling method are needed to solve the above-mentioned technical problems. Summary of the Invention

[0008] The purpose of this invention is to provide a bottom filling tool, a tubular structure, and a filling method that can reduce the labor intensity of workers and reduce the difficulty of construction.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] An underfilling tool, comprising a hollow cavity formed within the tool along its axial direction, and including:

[0011] Upper connector assembly;

[0012] The assembly tube is connected at one end to the upper connector assembly and is coaxially arranged with the upper connector assembly. The other end of the assembly tube is provided with a switch valve for closing or opening the hollow cavity.

[0013] A wireless control component is disposed in the assembly pipe and is communicatively connected to the switching valve. When the wireless control component receives a switching signal, it can control the switching valve to open or close.

[0014] A pressure control component is disposed in the assembly pipe and electrically connected to the switching valve. When the pressure control component receives a pressure change signal, it can control the switching valve to open or close.

[0015] Furthermore, the upper connector assembly includes an upper connector, which is connected to one end of the assembly tube, and a sealing member is provided inside the upper connector.

[0016] Furthermore, the wireless control component includes a signal processing unit and a first switch execution unit that are communicatively connected to each other. The signal processing unit is capable of receiving and processing switch signals, and the first switch execution unit is capable of controlling the switch valve to open or close.

[0017] Furthermore, the signal processing unit includes a signal receiving unit and a control unit that are connected in communication, and the control unit is electrically connected to the first switch execution unit.

[0018] Furthermore, the pressure control component includes a pressure sensing unit, a power supply unit, and a second switch execution unit that are connected in sequence. The pressure sensing unit is used to receive pressure change signals, and the second switch execution unit can control the switch valve to open or close.

[0019] Furthermore, a guide head is provided at the end of the fitting tube away from the upper connector assembly.

[0020] A tubular structure includes a tubular body, a packer, a screen tube, and an underfilling tool as described above. The packer is disposed at the upper end of the screen tube, the tubular body passes through the packer and the screen tube, and the underfilling tool is disposed at the lower end of the tubular body. The tubular body communicates with the hollow cavity of the underfilling tool.

[0021] A filling method for fracturing and sand-controlling filling operations of oil reservoirs using the tubing string structure described above includes the following steps:

[0022] S1. Assemble the tubing structure and, after assembly, transport it downhole to the designated location using tubing.

[0023] S2. Insert the tag ball with the open signal through the oil pipe until it falls into the bottom filling tool;

[0024] S3. The wireless control component receives the opening signal and controls the switch valve to open, so that the hollow cavity is connected to the tubing body and the tubing. If the switch valve is not open, the fluid is pumped into the tubing structure using the wellhead pump. When the fluid pressure reaches the first set value, the pressure control component receives the pressure change signal and controls the switch valve to open.

[0025] S4. The packer is set to seal the gap between the tubing body and the well wall;

[0026] S5. The fracturing fluid is pumped into the tubing structure using the wellhead pump. The fracturing fluid flows out through the bottom filling tool to fracture the oil layer and form a flow guide fracture.

[0027] S6. The sand fluid is pumped in using the wellhead pump. After the sand fluid flows out, it squeezes the guide joint to complete the sand filling of the loose oil layer and form a high-conductivity joint.

[0028] S7. Insert the tag ball with the relevant signal through the oil pipe until it falls into the bottom filling tool;

[0029] S8. The wireless control component receives the closing signal and controls the switching valve to close, so that the hollow cavity, the tubing body, and the tubing are closed. If the switching valve is not closed, the fluid is pumped into the tubing structure using a wellhead pump, and the fluid pressure is gradually reduced to a second set value. Then, the pressure control component receives the pressure change signal and controls the switching valve to close.

[0030] S9. Pull out the oil pipe to complete the fracturing and sand-proofing filling operation of the oil layer.

[0031] Furthermore, before step S1, well cleaning operations need to be performed.

[0032] Furthermore, after the well cleaning operation is completed, wall-protecting mud needs to be applied to the well wall to keep the well wall surface smooth.

[0033] The beneficial effects of this invention are:

[0034] This invention provides a bottom filling tool, in which an upper connector assembly connects to a mounting pipe. The mounting pipe contains a wireless control component and a pressure control component. Upon receiving a switching signal, the wireless control component controls a switching valve to open or close, thereby opening or closing the hollow cavity. When the wireless control component is inoperable, the pressure control component receives a pressure change signal and controls the switching valve to open or close, again opening or closing the hollow cavity. When open, fracturing and sand-controlling filling operations can be performed on the oil layer. After the operation is completed, the switching valve is closed. This method reduces the labor intensity of workers and simplifies construction.

[0035] The present invention provides a tubular structure comprising a tubular body, a packer, a screen pipe, and a bottom filling tool as described above, enabling fracturing and sand-controlling filling operations via the tubular structure. Using this tubular structure reduces the labor intensity of workers while also simplifying construction.

[0036] The filling method provided by this invention, which uses the tubing structure described above for fracturing and sand-controlling filling operations in oil reservoirs, can reduce the labor intensity of workers and reduce the difficulty of construction. Attached Figure Description

[0037] Figure 1 This is a cross-sectional view of a bottom filling tool according to the present invention;

[0038] Figure 2 This is a schematic diagram of the label ball of the present invention entering the column structure.

[0039] In the picture:

[0040] 1. Bottom filling tool; 11. Upper connector assembly; 111. Upper connector; 112. Sealing component; 113. Adapter; 12. Assembly tubing; 13. Guide head; 14. Wireless control assembly; 141. Signal receiving unit; 142. Control unit; 143. First switch actuation unit; 15. Pressure control assembly; 151. Pressure sensing unit; 152. Power supply unit; 153. Second switch actuation unit; 16. Switch valve; 2. Tubing body; 3. Packer; 4. Screen tube; 5. Oil layer; 6. Tag ball. Detailed Implementation

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0043] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] To reduce the labor intensity and construction difficulty of workers during oil reservoir fracturing and sand control filling operations, such as... Figure 1 As shown, the present invention provides a bottom filling tool. The bottom filling tool 1 has a hollow cavity formed inside it along the axial direction of the bottom filling tool 1. The bottom filling tool 1 includes: an upper connector assembly 11, a mounting tube 12, a wireless control assembly 14, and a pressure control assembly 15.

[0045] One end of the mounting tube 12 is connected to the upper connector assembly 11, and the mounting tube 12 and the upper connector assembly 11 are coaxially arranged. The other end of the mounting tube 12 is provided with a switch valve 16 for closing or opening the hollow cavity. The wireless control component 14 is fixedly installed in the mounting tube 12 and is communicatively connected to the switch valve 16. When the wireless control component 14 receives a switch signal, it can control the switch valve 16 to open or close. The pressure control component 15 is fixedly installed in the mounting tube 12 and is electrically connected to the switch valve 16. When the pressure control component 15 receives a pressure change signal, it can control the switch valve 16 to open or close.

[0046] After receiving a switch signal, the wireless control component 14 can control the switch valve 16 to open or close, thereby opening or closing the hollow cavity. When the wireless control component 14 is not working, the pressure control component 15 can receive a pressure change signal and control the switch valve 16 to open or close, thereby opening or closing the hollow cavity. When open, fracturing and sand-controlling filling operations can be performed on the oil layer 5. After the operation is completed, the switch valve 16 can be closed. This method reduces the labor intensity of workers and simplifies construction.

[0047] Furthermore, the upper connector assembly 11 includes an upper connector 111, which is connected to one end of the mounting tube 12. A sealing member 112 is provided within the upper connector 111. Specifically, in other embodiments, the upper connector 111 and the mounting tube 12 are connected via an adapter 113, facilitating the installation and connection between the upper connector 111 and the mounting tube 12. By providing the sealing member 112, a seal is achieved between the mounting tube 2 and the upper connector 111 when the upper connector 111 is connected to the tubing body 2, thereby preventing liquid from flowing out through the gap between the tubing body 2 and the upper connector 111 during operation.

[0048] Furthermore, the wireless control component 14 includes a signal processing unit and a first switch execution unit 143 that are communicatively connected. The signal processing unit can receive and process switch signals, and the first switch execution unit 143 can control the switch valve 16 to open or close. Specifically, the signal processing unit includes a signal receiving unit 141 and a control unit 142 that are communicatively connected. The control unit 142 is electrically connected to the first switch execution unit 143. The signal receiving unit 141, the control unit 142, and the first switch execution unit 143 are connected via optical fiber communication. When it is necessary to control the switch valve 16 to open or close, the tag ball 6 needs to be inserted into the hollow cavity. When the tag ball 6 passes through the signal receiving unit 141, the signal receiving unit 141 receives the switch signal from the tag ball 6 and then transmits the signal to the control unit 142. The control unit 142 processes the signal and obtains the open or closed signal contained in the tag ball 6. The control unit 142 controls the first switch execution unit 143 to control the switch valve 16, thereby realizing the action of the switch valve 16. In this embodiment, the tag ball 6 and the signal receiving unit 141 adopt radio frequency identification (RFID) technology. RFID technology is an existing mature technology, and its working principle will not be described in detail here.

[0049] When filling is needed, a tag ball 6 containing the "open" command is dropped, and the wireless control component 14 can open the switch valve 16 to carry out filling or well washing operations. When the switch valve 16 needs to be closed after filling is completed, a tag ball 6 containing the "close" command is dropped. This makes the filling operation very convenient and avoids the previous cumbersome process and additional tools.

[0050] Furthermore, the pressure control component 15 includes a pressure sensing unit 151, a power supply unit 152, and a second switch execution unit 153, which are connected in sequence. The pressure sensing unit 151 receives pressure change signals, and the second switch execution unit 153 controls the opening or closing of the switch valve 16. Specifically, in this example, the pressure sensing unit 151, the power supply unit 152, and the second switch execution unit 153 are connected via optical fiber. This pressure control component 15 is activated when the wireless control component 14 cannot function, for example, when the pump cannot be started. In this case, the entire tubing is blocked, and the wireless control component 14 cannot be activated by inserting a command tag. The pressure sensing unit 151 can only be activated by pressure. After sensing a pressure change signal, the pressure sensing unit 151 transmits this signal to the power supply unit 152. After receiving the signal, the power supply unit 152 transmits this signal to the second switch execution unit 153. After receiving the "open" or "close" signal, the second switch execution unit 153 executes the signal, which can open or close the switch valve 16. The above settings ensure that the switch valve 16 can be opened or closed smoothly, thereby enabling the filling operation.

[0051] Furthermore, a guide head 13 is fixedly installed at the end of the fitting pipe 12 away from the upper connector assembly 11. The main function of the guide head 13 is to guide the bottom filling tool 1 during its lowering process, ensuring that the bottom filling tool 1 is smoothly lowered into the well.

[0052] like Figure 2 As shown, this embodiment also provides a tubing string structure, including a tubing string body 2, a packer 3, a screen pipe 4, and a bottom filling tool 1 as described above. The packer 3 is located at the upper end of the screen pipe 4. The tubing string body 2 passes through the packer 3 and the screen pipe 4. The bottom filling tool 1 is located at the lower end of the tubing string body 2, and the hollow cavity of the tubing string body 2 and the bottom filling tool 1 are connected. In use, this tubing string structure is placed into the well. The packer 3 seals the gap between the tubing string body 2 and the well wall, and the screen pipe 4 serves to prevent sand from entering the well.

[0053] like Figure 2 As shown, this embodiment also provides a filling method for fracturing and sand-controlling filling operations of oil layer 5 using the above-described tubing structure, including the following steps:

[0054] S1. Assemble the tubing structure and, after assembly, transport it downhole to the designated location using tubing.

[0055] S2. The tag ball 6 with the open signal is dropped into the oil pipe until it falls into the bottom filling tool 1; specifically, the open signal is written into the tag ball 6 using software.

[0056] S3. The wireless control component 14 receives the open signal and controls the switch valve 16 to open, making the hollow cavity connected to the tubing body 2 and the tubing. If the switch valve 16 does not open, the wellhead pump is used to pump fluid into the tubing structure. When the fluid pressure reaches the first set value, the pressure control component 15 receives the pressure change signal and controls the switch valve 16 to open. During this process, the filling channel is opened. If there is severe sand production or rapid sand production in the formation, and the tubing has not yet reached the bottom of the well, opening the filling channel can serve as a circulation channel to circulate the sand in the wellbore, keep the wellbore unobstructed, and allow the tubing to be successfully lowered to the predetermined position.

[0057] S4. Packer 3 is set to seal the gap between the tubing body 2 and the well wall. Specifically, after the tubing structure is lowered to the bottom of the well, the packer 3 is set by pressurizing the wellhead, in preparation for sand control and backfilling.

[0058] S5. The fracturing fluid is pumped into the tubing structure using a wellhead pump. The fracturing fluid flows out through the bottom filling tool 1 to fracture the oil layer 5 and form a flow guide fracture.

[0059] S6. Use the wellhead pump to pump in sand fluid. After the sand fluid flows out, it squeezes the guide fracture to complete the sand filling of the loose oil layer 5 and form a high guide fracture.

[0060] S7. Insert the tag ball 6 with the relevant signal through the oil pipe until it falls into the bottom filling tool 1;

[0061] S8. The wireless control component 14 receives the shutdown signal and controls the switch valve 16 to close, thereby closing the hollow cavity, tubing body 2, and tubing. If the switch valve 16 is not closed, the fluid is pumped into the tubing structure using the wellhead pump, and the fluid pressure is gradually reduced to the second set value. Then, the pressure control component 15 receives the pressure change signal and controls the switch valve 16 to close, thus completing the task of closing the filling channel.

[0062] S9. Pull out the tubing to complete the fracturing and sand-controlling filling operation of oil layer 5. Specifically, packer 3, screen pipe 4, and bottom filling tool 1 remain in the well, completing the entire construction process. After the oil pump is installed at the wellhead, the oil in oil layer 5 will enter the wellbore through screen pipe 4, forming the oil production process.

[0063] Furthermore, before step S1, a well cleaning operation is required. This is to prevent complex situations such as narrowing, sand bridging, or collapse in certain well sections from affecting the installation of the tubing string.

[0064] Furthermore, after the well cleaning operation is completed, wall-protecting mud needs to be applied to the well wall to keep the well wall surface smooth, thereby facilitating the lowering of the tubing structure.

[0065] The effect of this embodiment

[0066] This invention addresses the problems of complex structure, cumbersome process, and low automation in existing fracturing and sand control bottom filling tools 1. Based on radio frequency identification (RFID) and pressure pulse technology, this invention transforms the existing structure of fracturing and sand control bottom filling tools 1 by adopting an advanced method that combines RFID and pressure pulse, thereby improving the automation level of bottom filling tools 1 and realizing the intelligentization and digitalization of downhole tools.

[0067] This invention solves the problem that existing fracturing sand control tools require auxiliary design tools to achieve filling construction, which is expensive and inconvenient to promote. By adopting an advanced method that combines radio frequency identification and pressure pulse, the construction cost is reduced and the number and scale of auxiliary tools are reduced.

[0068] This invention addresses the challenges of current tools and processes that lead to heavy workloads and errors for construction workers. By employing an advanced method combining radio frequency identification and pressure pulses, the opening and closing functions can be achieved simply by dropping the tag ball 6 into the well or by applying different pressure levels, significantly reducing the number of operations and labor intensity required.

[0069] This method solves the problems of high pump pressure, numerous high-pressure devices at the wellhead, and the potential dangers of frequent tool movement during current construction processes. By adopting an advanced method combining radio frequency identification and pressure pulses, it changes the construction approach by using wellhead ball dropping and pressure adjustment to avoid the hazards of high pressure.

[0070] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A filling method, characterized in that, The fracturing and sand-controlling backfilling operation for oil layer (5) includes the following steps: S1. Assemble the tubing structure and, after assembly, transport it downhole to the designated location using tubing. S2. The tag ball (6) with the open signal is inserted through the oil pipe until it falls into the bottom filling tool (1). A hollow cavity is opened in the bottom filling tool (1) along the axial direction of the bottom filling tool (1). S3. The wireless control component (14) receives the opening signal and controls the switch valve (16) to open, so that the hollow cavity is connected to the tubing body (2) and the tubing. If the switch valve (16) is not opened, the fluid is pumped into the tubing structure using the wellhead pump. When the fluid pressure reaches the first set value, the pressure control component (15) receives the pressure change signal and controls the switch valve (16) to open. S4. The packer (3) is set to seal the gap between the tubing body (2) and the well wall; S5. The fracturing fluid is pumped into the tubing structure using the wellhead pump. The fracturing fluid flows out through the bottom filling tool (1) to fracture the oil layer (5) and form a flow guide. S6. Use the wellhead pump to pump in sand fluid. After the sand fluid flows out, it squeezes the guide joint to complete the sand filling of the loose oil layer (5) and form a high guide joint. S7. Insert the tag ball (6) with the relevant signal through the oil pipe until it falls into the bottom filling tool (1); S8. The wireless control component (14) receives the closing signal and controls the switch valve (16) to close, so that the hollow cavity, the tubing body (2), and the tubing are closed. If the switch valve (16) is not closed, the fluid is pumped into the tubing structure using a wellhead pump, and the fluid pressure is gradually reduced to the second set value. Then, the pressure control component (15) receives the pressure change signal and controls the switch valve (16) to close. S9. Remove the oil pipe and complete the fracturing and sand-proofing filling operation of the oil layer (5).

2. The filling method according to claim 1, characterized in that, Before step S1, well cleaning operations need to be performed.

3. The filling method according to claim 2, characterized in that, After the well cleaning operation is completed, protective mud is applied to the well wall to keep the well wall surface smooth.

4. A bottom filling tool, characterized in that, The filling method described in any one of claims 1-3 includes a hollow cavity formed within the bottom filling tool (1) along its axial direction, comprising: Upper connector assembly (11); A fitting tube (12) is installed, one end of which is connected to the upper connector assembly (11), and the fitting tube (12) and the upper connector assembly (11) are arranged on the same axis. The other end of the fitting tube (12) is provided with a switch valve (16) for closing or opening the hollow cavity. A wireless control component (14) is disposed in the assembly pipe (12) and is communicatively connected to the switch valve (16). When the wireless control component (14) receives a switch signal, it can control the switch valve (16) to open or close. Pressure control component (15) is disposed in the assembly pipe (12) and electrically connected to the switching valve (16). When the pressure control component (15) receives a pressure change signal, it can control the switching valve (16) to open or close.

5. A bottom filling tool according to claim 4, characterized in that, The upper connector assembly (11) includes an upper connector (111), which is connected to one end of the assembly tube (12), and a sealing member (112) is provided inside the upper connector (111).

6. A bottom filling tool according to claim 4, characterized in that, The wireless control component (14) includes a signal processing unit and a first switch execution unit (143) that are interconnected. The signal processing unit is able to receive and process switch signals, and the first switch execution unit (143) is able to control the switch valve (16) to open or close.

7. A bottom filling tool according to claim 6, characterized in that, The signal processing unit includes a signal receiving unit (141) and a control unit (142) connected in communication, and the control unit (142) is electrically connected to the first switch execution unit (143).

8. A bottom filling tool according to claim 4, characterized in that, The pressure control component (15) includes a pressure sensing unit (151), a power supply unit (152), and a second switch execution unit (153) connected in sequence. The pressure sensing unit (151) is used to receive pressure change signals, and the second switch execution unit (153) can control the switch valve (16) to open or close.

9. A bottom filling tool according to claim 4, characterized in that, A guide head (13) is provided at the end of the fitting tube (12) away from the upper connector assembly (11).

10. A tubular column structure, characterized in that, The device includes a tubular body (2), a packer (3), a screen tube (4), and a bottom filling tool as described in any one of claims 4-9. The packer (3) is disposed at the upper end of the screen tube (4), the tubular body (2) passes through the packer (3) and the screen tube (4), and the bottom filling tool (1) is disposed at the lower end of the tubular body (2). The tubular body (2) communicates with the hollow cavity of the bottom filling tool (1).

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