Crushing and salvaging device and crushing and salvaging method for underground fallen blocks

Abstract

The invention provides a crushing and salvaging device for underground fallen pieces, which comprises a crushing mechanism and a salvaging mechanism, the crushing mechanism comprises a jet flow pipe column and a jet flow channel which is formed in the jet flow pipe column and allows drilling fluid to pass through, and the salvaging mechanism comprises a salvaging cylinder which is arranged outside the jet flow pipe column in a sleeving manner, the bottom end of the jet flow pipe column is provided with a jar used for enabling underground falling blocks to be shattered into broken blocks, and the broken blocks can enter the fishing barrel under the pushing effect of the drilling fluid.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration, and more specifically to a crushing and retrieval device for downhole rock fragments, and a crushing and retrieval method. Background Technology

[0002] As oil and gas exploration and development moves towards deeper and ultra-deeper reservoirs, the geological conditions become increasingly complex, with structural fault zones, faults and fractures developing, stress concentrations in the ground, and formation fracturing. Drilling faces the risks of well leakage, wellbore instability, and even stuck drill bits.

[0003] Under current drilling conditions, the main approach to dealing with blockages caused by wellbore instability is to enhance the properties of the drilling fluid and carry them out during drilling. However, if the wellbore collapses severely and the blockages are large, they may not be able to be carried out, which can easily lead to stuck drill bits or even drill string getting stuck.

[0004] Given the limited rock-carrying capacity of existing drilling fluids, there is a need in the art to provide a crushing and retrieval device for downhole rock, which can effectively clean the wellbore. Summary of the Invention

[0005] The purpose of this invention is to provide a crushing and retrieval device for downhole rock fragments, which can be used for specialized retrieval work under conditions where the drilling fluid has insufficient rock-carrying capacity.

[0006] According to a first aspect of the invention, a fracturing and retrieval device for downhole rock fragments is provided, comprising a fracturing mechanism, the fracturing mechanism including a jet string and a jet channel formed within the jet string and allowing drilling fluid to pass through, and

[0007] The retrieval mechanism includes a retrieval cylinder sleeved outside the jet column.

[0008] The jet string is equipped with a shocker at the bottom end to break downhole rocks into smaller pieces, which can then enter the retrieval cylinder under the propulsion of the drilling fluid.

[0009] In one embodiment, the shock absorber includes a vibrating portion configured in a columnar shape and connected to the jet column, and a plurality of crushing heads fixed to the vibrating portion.

[0010] In one embodiment, the crushing mechanism further includes a plurality of jet holes inclinedly arranged on the vibrating part, the jet holes and the crushing head being alternately arranged circumferentially at the lower end face of the vibrating part.

[0011] In one embodiment, the diameter of the shocker is smaller than the diameter of the jet column, and a plurality of spaced jet holes are provided at the lower end face of the jet column, the jet holes being arranged around the shocker.

[0012] In one embodiment, an annular cavity is formed between the retrieval tube and the jet column, and the retrieval mechanism includes a cover plate for sealing the annular cavity, the cover plate being composed of a plurality of anti-drop segments hinged to the lower end face of the retrieval tube and for abutting against the jet column.

[0013] In one embodiment, a check valve is provided on the retrieval cylinder for controlling the movement path of the anti-drop segment.

[0014] The crushing and salvage device also includes a switching valve connected to the jet orifice, and a controller connected to the check valve and the switching valve respectively, for causing the anti-drop segment to work synchronously with the jet orifice.

[0015] In one embodiment, the crushing and salvage device further includes a sensor for measuring the weight of the salvage cylinder.

[0016] In one embodiment, the upper end face of the retrieval cylinder is provided with circulation holes that allow only the drilling fluid to pass through. A plurality of circulation holes are distributed equidistantly along the circumference, and the diameter of the circulation holes is 10-20 mm.

[0017] According to a second aspect of the present invention, a crushing and retrieval method using a crushing and retrieval device according to the above description is provided, comprising the following steps:

[0018] S1. Pull up the drill string and lower the crushing and salvage device;

[0019] S2. The downhole rock is broken into smaller pieces by the shock absorber; the check valve and the on / off valve are opened simultaneously by the controller, and the smaller pieces enter the retrieval cylinder under the pushing action of the drilling fluid; the weight of the retrieval cylinder is measured by the sensor.

[0020] S3. Determine whether the retrieval tube is full. If it is full, remove the crushing and retrieval device. If it is not full, repeat step S2.

[0021] In one embodiment, S3 further includes:

[0022] If the weight detected by the sensor does not change during the repeated process of step S2, it is considered that the broken pieces at the bottom of the well have been retrieved, and the broken retrieval device is then removed.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] Firstly, this invention is a specialized retrieval operation performed under conditions where the drilling fluid's rock-carrying capacity is insufficient. Specifically, downhole rock is first broken into smaller pieces using a shock absorber, and then the broken pieces are pushed into a retrieval cylinder by high-pressure drilling fluid ejected from the jet orifice, thus completing the breaking and retrieval process. This method not only helps to purify wellbore conditions but also prevents further drilling and stuck pipe.

[0025] In addition, compared with the conventional method of carrying rock with drilling fluid, this device can remove large rock fragments at the bottom of the well, and has the characteristics of convenient construction and safety and reliability.

[0026] Secondly, the present invention can synchronously open the check valve and the switching valve through the controller, thereby ensuring that the anti-fall fragment and the jet hole can work synchronously (i.e., the opening and closing of the two). Therefore, the jet hole is always open whenever the cover plate is in the unfolded state, thereby ensuring that the broken piece always moves upward under the action of the drilling fluid when the cover plate is in the unfolded state, so as to further prevent the broken piece from falling back. Attached Figure Description

[0027] The invention will now be described in detail with reference to the accompanying drawings, in which:

[0028] Figure 1 The schematic diagram illustrates the structure of a crushing and salvage device for downhole debris according to the present invention;

[0029] Figure 2 for Figure 1 The partial view in the image shows both the unfolded and closed states of the cover.

[0030] Figure 3 This is an embodiment of the crushing and retrieval device for downhole debris according to the present invention.

[0031] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0032] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0033] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation", "connection", "linking", "fixing", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components.

[0035] Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] The invention will now be further described with reference to the accompanying drawings.

[0037] Figure 1 The schematic diagram shows the structure of the crushing and salvage device 100 for downhole debris according to the present invention;

[0038] Figure 2 for Figure 1 The partial view in the image shows both the unfolded and closed states of the cover.

[0039] Figure 3 This is an embodiment of the crushing and retrieval device 100 for downhole rock falling according to the present invention.

[0040] like Figure 1 As shown, according to a first aspect of the present invention, a breakage and retrieval device 100 for downhole debris is provided, comprising a breakage mechanism and a retrieval structure. The breakage mechanism includes a jet string 11 and a jet channel formed within the jet string 11. Preferably, the jet channel allows drilling fluid to pass through for effective guiding. The retrieval mechanism includes a retrieval cylinder 20 sleeved outside the jet string 11. Preferably, the retrieval cylinder 20 is used to retrieve the broken debris 101 (described below) and can smoothly bring it out of the wellbore (not shown in the drawings).

[0041] In one embodiment of the present invention, such as Figure 1 As shown, a shock absorber 12 is provided at the bottom end of the jet string 11. Preferably, the shock absorber 12 can break the downhole rock into fragments 101, and the jet orifice (201 / 202, described below) can pressurize the drilling fluid from the jet channel and eject it towards the fragments 101. Thus, the fragments 101 can smoothly enter the retrieval cylinder 20 under the propulsion of the drilling fluid, so as to further complete the retrieval of the fragments 101.

[0042] Preferably, the thickness of the downhole block in this invention is usually greater than or equal to the annular cross-sectional area; the weight of the downhole block usually exceeds the rock-carrying capacity; and the size of the broken block 101 is usually 3cm × 3cm ±.

[0043] In one embodiment, such as Figure 1 As shown, the vibrator 12 includes a vibrating portion 121 connected to the jet string 11, and a breaker head fixed to the vibrating portion 121. Preferably, the vibrating portion 121 is constructed in a columnar form, and its end face is made of cemented carbide. In this invention, the vibrating portion 121 includes, but is not limited to, cylindrical, square prism, and hexagonal prism structures. In this invention, multiple breaker heads are provided and fixedly installed at the lower end face of the vibrating portion 121, and the breaker heads are typically constructed as small-sized two- or three-bladed fan-shaped drill bits.

[0044] In one embodiment, the crushing mechanism includes a drive power module (not shown) connected to the shock absorber 12. In this invention, the drive power module is a drive motor. Preferably, the drive motor is connected to the shock absorber 12 to ensure stable operation of the shock absorber 12 downhole.

[0045] In one embodiment of the present invention, such as Figure 1 As shown, the crushing mechanism also includes a plurality of jet holes 201 inclinedly arranged on the vibrating part 121. Preferably, the jet holes 201 and the crushing head are arranged alternately along the circumferential direction at the lower end face of the vibrating part 121.

[0046] Therefore, while the breaker head is performing its breaking work, high-pressure drilling fluid is also ejected from the jet hole 201. In this way, on the one hand, the breaker head and the high-pressure drilling fluid ejected from the jet hole 201 can simultaneously contribute to breaking the downhole rock into fragments 101, thereby ensuring that the fragments 101 meet the size requirements for entering the retrieval cylinder 20; on the other hand, the drilling fluid can also play a cooling role when the breaker head is working, further improving the breaking efficiency. Thus, under the propulsion of the high-pressure drilling fluid, the fragments 101 can smoothly enter the retrieval cylinder 20 to further complete the retrieval work of the fragments 101.

[0047] In other embodiments, the diameter of the shock absorber 12 is smaller than the diameter of the jet column 11. Therefore, as... Figure 3 As shown, multiple jet holes 202 are provided at intervals on the lower end face of the jet column 11. Preferably, the multiple jet holes 202 are arranged around the shock absorber 12.

[0048] In this embodiment, since the jet orifice 202 is vertically aligned with the broken piece 101 at the bottom of the well, the breaking ability of the drilling fluid can be improved in this way, ensuring that the broken piece 101 meets the size requirements for entering the retrieval cylinder 20. In addition, since the high-pressure drilling fluid ejected from the jet orifice 202 moves in a straight line and can be more easily aligned with the broken piece 101, it ensures that the broken piece 101 can smoothly enter the retrieval cylinder 20, which facilitates subsequent retrieval work.

[0049] In one embodiment, the flow velocity of the drilling fluid flowing out through the jet holes 201 / 202 is typically high. For example, the jet velocity for a Φ215.9mm wellbore with a 30L displacement is typically 150-300L / s. In this invention, because the flow velocity of the drilling fluid flowing out through the jet holes 201 / 202 is high, the drilling fluid will have a certain crushing effect when it impacts the broken block 101. Furthermore, when used with the crushing head, it can minimize the size of the broken block 101, thereby increasing the success rate of the broken block 101 entering the retrieval cylinder 20 and thus improving the crushing and retrieval efficiency of the crushing and retrieval device 100 for downhole block dropping.

[0050] In one embodiment, such as Figure 1 and 2 As shown, an annular cavity is formed between the retrieval cylinder 20 and the jet string 11, and the retrieval mechanism also includes a cover plate for sealing the annular cavity. Preferably, the cover plate can switch between an extended state and a closed state under the action of a check valve (described below), thereby ensuring that the broken piece 101 is prevented from falling back during repeated retrieval, thus further improving the working efficiency of the broken piece retrieval device 100 for downhole block dropping.

[0051] In this invention, such as Figure 1 and 2 As shown, the cover plate is composed of multiple anti-drop segments 22. Preferably, the first end of the anti-drop segment 22 is hinged to the lower end face of the retrieval cylinder 20, so the anti-drop segment 22 can rotate on the retrieval cylinder 20 through the first end. The second end of the anti-drop segment 22 can selectively abut against the jet column 11. In other words, when the cover plate is in the closed state, the anti-drop segment 22 can abut against the jet column 11 through the second end; and when the cover plate is in the unfolded state, the anti-drop segment 22 can separate from the jet column 11.

[0052] Therefore, by changing the movement path of the anti-falling segment 22, the state of the cover plate (open state and closed state) can be adjusted, thereby enabling the retrieval cylinder 20 to open and close. This not only allows for the successful retrieval of the broken piece 101, but also prevents the broken piece 101 from falling back during repeated retrieval.

[0053] In one embodiment, a sealing sleeve (not shown in the drawings) is provided at the junction of the anti-drop segment 22 and the jet string 11. Therefore, when the cover is closed, the anti-drop segment 22 can form a sealed connection with the jet string 11 through the sealing sleeve to ensure that the broken piece 101 that has entered the retrieval cylinder 20 can be successfully retrieved from the well.

[0054] According to the present invention, the break-and-retrieve device 100 for downhole block falling also includes a switching valve (not shown) connected to the jet orifice 201 / 202, and a controller (not shown) connected to the check valve and the switching valve respectively. Preferably, the controller is configured to ensure that the anti-fall segment 22 and the jet orifice 201 / 202 work synchronously (i.e., their opening and closing). Therefore, whenever the cover plate is in the unfolded state, the jet orifice 201 / 202 is in the open state, thereby ensuring that the broken block 101 always moves upward under the action of the drilling fluid when the cover plate is in the unfolded state, so as to further prevent the broken block 101 from falling back.

[0055] In one embodiment, the break-and-retrieve device 100 for downhole debris further includes a sensor (not shown) for measuring the weight of the retrieval cylinder 20. Preferably, the present invention can more easily determine whether the retrieval cylinder 20 is full based on the change in the weight of the retrieval cylinder 20 measured by the sensor.

[0056] In this invention, when the data measured by the sensor indicates that the retrieval cylinder 20 is full, a crushing and retrieval device 100 for downhole debris is provided; when the data measured by the sensor indicates that the retrieval cylinder 20 is not full, the crushing and retrieval work needs to be repeated until the retrieval cylinder 20 is determined to be full.

[0057] It is worth noting that if the data detected by the sensor does not change after repeated breaking and retrieval operations, it is considered that all the broken pieces 101 at the bottom of the well have been retrieved, and thus the breaking and retrieval device 100 for downhole blocks can be proposed.

[0058] In one embodiment, such as Figure 1 As shown, a circulation hole 23 is provided on the upper end face of the retrieval cylinder 20, allowing only drilling fluid to pass through. In this way, excess drilling fluid during the retrieval process is discharged outward through the circulation hole 23 for recycling, and then used again for breaking and retrieval through the jet channel and jet holes 201 / 202.

[0059] Preferably, a plurality of circulation holes 23 are provided, and the plurality of circulation holes 23 are equidistantly distributed along the circumference. In this invention, a total of six circulation holes 23 are provided, and adjacent circulation holes 23 form a 60° included angle, and the diameter of the circulation holes 23 is 10-20 mm.

[0060] According to a second aspect of the present invention, a method for retrieving fragmented rock using a fragmentation and retrieval device 100 for downhole rock as described above is provided, comprising the following steps:

[0061] Step 1: Raise the drill string assembly and lower the crushing and salvage device;

[0062] Step 2: The downhole rock is broken into fragments 101 by the shock absorber 12. At the same time, the check valve and the on / off valve are opened synchronously by the controller. The fragments 101 enter the retrieval cylinder 20 under the pushing action of the drilling fluid. The weight of the retrieval cylinder 20 is measured by the sensor.

[0063] Step 3: Determine if the retrieval cylinder 20 is full. If it is full, remove the crushing and retrieval device 100 used for downhole debris. If it is not full, repeat step 2.

[0064] It is worth noting that if the weight detected by the sensor does not change during the repeated steps two to four, it is considered that all the broken pieces 101 at the bottom of the well have been retrieved, and the crushing and retrieval device 100 for the broken pieces falling down the well can be taken out.

[0065] In this invention, when wellbore instability, large chunks falling from the vibrating screen (not shown), frequent blockages or jamming of the drill string occur during drilling, the drill string assembly needs to be retrieved.

[0066] After confirming that all the broken pieces 101 at the bottom of the well have been retrieved, the drill string assembly can be lowered back in to resume normal drilling operations.

[0067] Compared with existing technologies, the advantages of this invention are:

[0068] Firstly, this invention is a specialized retrieval operation performed under conditions where the drilling fluid's rock-carrying capacity is insufficient. Specifically, downhole rock is first broken into fragments 101 by a shock absorber 12. Then, high-pressure drilling fluid ejected from jet holes 201 / 202 pushes the fragments 101 into the retrieval cylinder 20, thus completing the breaking and retrieval process. This method not only helps to purify wellbore conditions but also prevents further drilling and stuck pipe.

[0069] In addition, compared with the conventional method of carrying rock with drilling fluid, this device can remove large rock fragments at the bottom of the well, and has the characteristics of convenient construction and safety and reliability.

[0070] Secondly, the present invention can synchronously open the check valve and the switching valve through the controller, thereby ensuring that the anti-fall segment 22 and the jet orifice 201 / 202 can work synchronously (i.e., the opening and closing of the two). Therefore, whenever the cover plate is in the unfolded state, the jet orifice 201 / 202 is in the open state, thereby ensuring that the broken block 101 always moves upward under the action of the drilling fluid when the cover plate is in the unfolded state, so as to further prevent the broken block 101 from falling back.

[0071] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the scope of the present invention, and such changes or modifications should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A crushing and salvage device for downhole rock spills, comprising: The breaking mechanism includes a jet string (11) and a jet channel formed within the jet string (11) that allows drilling fluid to pass through. The retrieval mechanism includes a retrieval cylinder (20) sleeved outside the jet column (11). The jet string (11) is provided with a shocker (12) at the bottom end for breaking downhole blocks into fragments (101), which can enter the retrieval cylinder (20) under the pushing action of the drilling fluid.

2. The crushing and retrieval device for downhole debris according to claim 1, characterized in that, The shock absorber (12) includes a vibrating part (121) configured in a columnar shape and connected to the jet column (11), and a plurality of crushing heads fixed to the vibrating part (121).

3. The crushing and retrieval device for downhole debris according to claim 2, characterized in that, The crushing mechanism also includes a plurality of jet holes that are inclinedly arranged on the vibrating part (121), and the jet holes and the crushing head are alternately arranged circumferentially on the lower end face of the vibrating part (121).

4. The crushing and retrieval device for downhole debris according to claim 2, characterized in that, The diameter of the shocker (12) is smaller than the diameter of the jet column (11), and a plurality of jet holes are provided at intervals on the lower end face of the jet column (11), the jet holes being arranged around the shocker (12).

5. The crushing and retrieval device for downhole debris according to claim 3 or 4, characterized in that, An annular cavity is formed between the retrieval cylinder (20) and the jet column (11). The retrieval mechanism includes a cover plate for sealing the annular cavity. The cover plate consists of a plurality of anti-drop segments (22) hinged to the lower end face of the retrieval cylinder (20) and used to abut against the jet column (11).

6. The crushing and retrieval device for downhole debris according to claim 5, characterized in that, A check valve is provided on the retrieval cylinder (20) to control the movement path of the anti-drop segment (22). The crushing and salvage device also includes a switching valve connected to the jet hole, and a controller connected to the check valve and the switching valve respectively, for causing the anti-drop segment (22) to work synchronously with the jet hole.

7. The crushing and retrieval device for downhole debris according to any one of claims 1 to 6, characterized in that, The crushing and retrieval device also includes a sensor for measuring the weight of the retrieval cylinder (20).

8. The crushing and retrieval device for downhole debris according to claim 7, characterized in that, The upper end face of the retrieval cylinder (20) is provided with circulation holes (23) that allow only the drilling fluid to pass through. Multiple circulation holes (23) are distributed equidistantly along the circumference, and the diameter of the circulation holes (23) is 10-20 mm.

9. A method for crushing and retrieving objects using the crushing and retrieving device according to any one of claims 1 to 8, comprising the following steps: S1. Pull up the drill string and lower the crushing and salvage device; S2. The downhole rock is broken into fragments (101) by the shocker (12); the check valve and the switch valve are opened synchronously by the controller, and the fragments (101) enter the retrieval cylinder (20) under the pushing action of the drilling fluid; the weight of the retrieval cylinder (20) is measured by the sensor. S3. Determine whether the scooping cylinder (20) is full. If it is full, remove the crushing and scooping device. If it is not full, repeat step S2.

10. The crushing and retrieving method according to claim 9, characterized in that, S3 further includes: If the weight detected by the sensor does not change during the repeated process of step S2, it is considered that the broken block (101) at the bottom of the well has been retrieved, and the broken retrieval device is then removed.

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