A magnetic focusing hydraulic sandblasting perforation fracturing device and method

Abstract

The present invention discloses a magnetic focusing hydraulic sandblasting perforating and fracturing device and method. The device includes a pipe body, and a spray gun is arranged inside the pipe body, and an electromagnetic component is sleeved on the spray gun. When the electromagnetic component is powered on, the electromagnetic component generates a first magnetic field consistent with the axial direction of the spray gun. A plurality of nozzles are arranged on the side wall of the spray gun. A magnetic component is arranged at one end of the nozzle connected to the spray gun. The magnetic component generates a second magnetic field consistent with the axial direction of the nozzle. When using this device for sandblasting perforating and fracturing, magnetic fluid abrasive is arranged inside the spray gun. The device utilizes the acceleration effect of the magnetic field on the magnetic abrasive and the aggregation effect of the magnetic part on the fluid, effectively improving the jet impact performance and enhancing the jet aggregation degree, thereby achieving the reduction of the nozzle wear rate, improving the reliability of the nozzle, and realizing the precise perforating and fracturing effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil production equipment, and relates to a magnetic focusing hydraulic sandblasting perforating and fracturing device and method. Background Art

[0002] The hydraulic sandblasting perforating and fracturing technology is to pressurize a liquid mixed with a certain amount of abrasive through a fracturing truck and pump it to the formation through a tubing. The abrasive liquid forms a high-speed sand-containing jet at the perforating nozzle, impacting the casing, cement sheath, and near-well formation rock to form perforation holes with a certain diameter and depth. During subsequent fracturing, proppants can be filled into the fracture to complete the sand addition operation. Since the nozzles of the currently used perforators are usually directly fixed on the pipe string, during hydraulic sandblasting construction, the high-speed movement of the sand-containing liquid will inevitably cause accelerated erosion and wear of the nozzles, resulting in an increase in the nozzle aperture. The perforating pressure provided by the original pump unit cannot reach the range requirement, the jet diverges, and the perforation positioning is inaccurate, greatly reducing the reliability of the nozzles. Summary of the Invention

[0003] Aiming at the problems existing in the prior art, the present invention provides a magnetic focusing hydraulic sandblasting perforating and fracturing device and method, so as to reduce the nozzle wear rate, improve the jet impact performance, enhance the jet aggregation degree, and achieve the accurate perforating and fracturing effect.

[0004] The present invention is realized through the following technical solutions:

[0005] A magnetic focusing hydraulic sandblasting perforating and fracturing device includes a pipe body. An injection gun is arranged inside the pipe body, and an electromagnetic component is sleeved on the injection gun. When the electromagnetic component is powered on, the electromagnetic component generates a first magnetic field consistent with the axial direction of the injection gun.

[0006] A plurality of nozzles are arranged on the side wall of the injection gun. A magnetic component is arranged at one end of the nozzle connected to the injection gun. The magnetic component generates a second magnetic field consistent with the axial direction of the nozzle.

[0007] The inside of the injection gun is used to arrange magnetic fluid abrasive.

[0008] Preferably, the inside of the pipe body includes a first cavity part and a second cavity part. The electromagnetic component is arranged in the first cavity part, and the plurality of nozzles are arranged in the second cavity part.

[0009] Preferably, a threaded pipe is arranged in the first cavity part. The inner wall of the first cavity part is provided with internal threads, and the outer wall of the threaded pipe is provided with external threads. The first cavity part is threadedly connected to the threaded pipe. The electromagnetic component is arranged inside the threaded pipe.

[0010] Preferably, a plurality of nozzle supports are arranged at intervals along the axial direction of the second cavity portion; the plurality of nozzles are arranged inside the plurality of nozzle supports.

[0011] Preferably, the inner wall of the spray gun is provided with internal threads.

[0012] Preferably, at one end of the spray gun connected to the oil pipe, a flow guiding member is provided, and the flow guiding member is threadedly connected to the spray gun.

[0013] Preferably, the magnetic assembly is a combination of an axially magnetized permanent magnet and a radially magnetized permanent magnet.

[0014] Preferably, the magnetic assembly is made of neodymium iron boron.

[0015] Preferably, the inner wall of the nozzle is of a fish scale structure.

[0016] A magnetic focusing hydraulic sandblasting perforation and fracturing method uses any one of the above magnetic focusing hydraulic sandblasting perforation and fracturing devices and is carried out through the following steps:

[0017] S1: Lower the magnetic focusing hydraulic sandblasting perforation and fracturing device into the construction target reservoir;

[0018] S2: Pump magnetic fluid abrasive into the spray gun;

[0019] S3: Turn on the power supply of the electromagnetic assembly. The electromagnetic assembly generates a magnetic field consistent with the axial direction of the spray gun. When the magnetic fluid abrasive flows through the spray gun, the first magnetic field pushes the magnetic fluid abrasive to accelerate its transmission in the spray gun;

[0020] S4: When the magnetic fluid abrasive flows through the nozzle, under the action of the second magnetic field generated by the magnetic assembly, the jet flow beam is focused, and the perforation and fracturing process of the perforation layer is completed.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] A magnetic focusing hydraulic sandblasting perforation and fracturing device adds magnetic fluid abrasive to the jet flow. At the same time, an electromagnetic assembly capable of generating a magnetic field consistent with the axial direction of the spray gun is provided. The electromagnetic assembly can effectively apply an external magnetic field to the magnetic fluid abrasive in the spray gun to accelerate it, and the movement rate of the magnetic fluid abrasive in the nozzle can be assisted to be advanced by adjusting the magnetic field intensity. In addition, a magnetic assembly is provided at the inlet of the nozzle. The magnetic assembly can improve the jet flow aggregation degree, effectively relieve the wear of the abrasive on the spraying assembly. This device enables the spraying rate and aggregation degree of the jet flow to effectively meet the process requirements, improves the reliability of the nozzle, and achieves an accurate perforation and fracturing effect.

[0023] Furthermore, the inner cavity of the spray gun is a spiral channel, which intensifies the disturbance of the magnetic fluid abrasive in the spray gun and further increases its movement speed.

[0024] Furthermore, the flow guide member can smoothly convert the axial flow of the fluid into a rotational flow, reducing the erosion of the fluid on the spray gun.

[0025] Furthermore, the magnetic component is a combination of an axially magnetized permanent magnet and a radially magnetized permanent magnet, which effectively improves the aggregation degree of the fluid and reduces the erosion of the fluid on the nozzle.

[0026] Furthermore, the inner wall of the nozzle is a fish-scale structure. The fish-scale rough inner wall can improve the wear resistance and erosion resistance of the nozzle.

[0027] A magnetic focusing hydraulic sandblasting perforation fracturing method accelerates the magnetic fluid abrasive through the first magnetic field generated by the electromagnetic component, aggregates the magnetic fluid abrasive through the second magnetic field generated by the magnetic component, is convenient to use and operate, reduces the wear rate of the nozzle, improves the jet impact performance, enhances the jet aggregation degree, and achieves the accurate perforation fracturing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic structural diagram of the device of the present invention.

[0030] Wherein: 1, threaded pipe; 2, upper centralizer; 3, flow guide member; 4, spray gun; 5, electromagnetic component; 6, internal thread; 7, nozzle support; 8, nozzle; 9, nozzle cap; 10, shock-absorbing layer; 11, erosion-proof cover plate; 12, sealing ring; 13, magnetic component; 14, lower centralizer; 15, guide shoe; 16, magnetic fluid abrasive; 17, pipe body, 171, first cavity part; 172, second cavity part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0033] It should be noted that like reference numerals and letters denote like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

[0034] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0035] In addition, if the term "horizontal" is used, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0036] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "coupled" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The present invention will be further described in detail below with reference to the accompanying drawings:

[0038] A nano-magnetic fluid, also known as a magnetic liquid, is a stable colloidal solution in which magnetic nanoparticles are coated with surfactants or charged, enabling the nano-sized magnetic particles to be uniformly dispersed in a base liquid. Under the action of an external magnetic field, the magnetic particles in the magnetic fluid are rapidly magnetized, move, and aggregate or arrange into a chain-like structure under the magnetic force. When the magnetic field is removed, the magnetic dipole moments of the magnetic particles in the magnetic fluid are instantaneously randomly distributed, and the volume magnetization rapidly decreases to zero. At this time, the fluid has good fluidity. With the development of magnetic fluids, magnetic fluid propulsion technology has also made great progress. Some studies have shown that applying magnetic fluid propulsion technology to abrasive jets has a significant auxiliary effect on the jetting effect. When an alternating current is passed through a multi-phase excitation alternating current coil around a flow channel, when the magnetic fluid abrasive flows through the flow channel wound with the coil, a moving magnetic field will be generated on the magnetic fluid in the flow channel. The moving magnetic field will generate an induced current on the magnetic fluid. Through the dual action of the current and the magnetic field, the magnetic fluid will be forced to accelerate forward in the flow channel. In addition, the magnetic nanoparticles in the magnetic fluid also have good tribological properties such as special anti-wear, friction reduction, and high load-bearing capacity. Mixing the magnetic fluid into the abrasive can effectively alleviate the wear of the abrasive on the jetting components.

[0039] Therefore, in the present invention, a magnetic fluid is mixed into an abrasive to form a uniform suspension. Under the dual action of an external electric field and a magnetic field, the jet impact performance is assisted to be improved. At the same time, by controlling the magnetic field intensity, the jet aggregation degree is enhanced to achieve an accurate perforation fracturing effect.

[0040] As Figure 1 shown, a magnetic force focusing hydraulic sandblasting perforation fracturing device includes a threaded pipe 1, an upper centralizer 2, a flow guide member 3, a spray gun 4, an electromagnetic assembly 5, a nozzle support 7, a nozzle 8, a nozzle cap 9, a shock-absorbing layer 10, an erosion-proof cover plate 11, a sealing ring 12, a magnetic assembly 13, a lower centralizer 14, a guide shoe 15, a magnetic fluid abrasive 16, a pipe body 17, and a control device of the device. Among them, the flow guide member 3 can be a flow guide device, and the electromagnetic assembly 5 can be an electromagnet. The flow guide member 3 is arranged at one end of the spray gun 4 connected to the oil pipe. The flow guide member 3 is threadedly connected to the spray gun 4 to guide the magnetic fluid abrasive 16 to smoothly convert the axial flow into a rotational flow.

[0041] The interior of the pipe body 17 includes a first cavity portion 171 and a second cavity portion 172. The electromagnetic assembly 5 is arranged in the first cavity portion 171, and a plurality of nozzles 8 are arranged in the second cavity portion 172. The threaded pipe 1 is arranged in the first cavity portion 171. The inner wall of the first cavity portion 171 is provided with internal threads, and the outer wall of the threaded pipe 1 is provided with external threads. The first cavity portion 171 is threadedly connected to the threaded pipe 1; the electromagnetic assembly 5 is arranged inside the threaded pipe 1.

[0042] The interior of the spray gun 4 is a hollow inner spiral flow channel, which is provided with an internal thread 6. The pitch is preferably 60 mm, the groove depth is preferably 4 mm, and the groove width is preferably 10 mm. Magnetic nanoparticles are added to the fluid in the spiral channel to form a thermodynamically stable magnetic fluid abrasive. An axial driving force is generated by the dual action of the magnetic field on the magnetic fluid in the abrasive, so that the magnetic fluid abrasive is accelerated through the spiral channel, improving the impact rate and enhancing the jet collimation.

[0043] The electromagnetic assembly 5 is sleeved on the outer wall of the spray gun 4; the electromagnetic assembly 5 is electrically connected to the control device; when the electromagnetic assembly 5 is powered on, the electromagnetic assembly 5 generates a first magnetic field consistent with the axial direction of the spray gun 4; a plurality of nozzles 8 are arranged on the side wall of the spray gun 4, and the magnetic assembly 13 is arranged at one end of the nozzle 8 connected to the spray gun 4; the magnetic assembly 13 generates a second magnetic field consistent with the axial direction of the nozzle 8. The magnetic assembly 13 can be a permanent magnet ring, and the material is neodymium iron boron. Preferably, it is a combined structure of an axially magnetized permanent magnet ring and a radially magnetized permanent magnet ring, providing a uniform axial magnetic field for the magnetic fluid abrasive 16, improving the axial center aggregation degree of the abrasive flowing through the nozzle 8, and reducing the wall surface wear at the nozzle inlet.

[0044] The nozzle support 7 is embedded in the body of the pipe 17, preferably arranged in the second cavity 172, and evenly distributed along the circumferential and axial directions of the spray gun 4. The number can be 6. The nozzle 8 is threadedly connected to the nozzle support 7. When the nozzle is damaged, a new nozzle can be replaced in time. Preferably, it is an isochronous deformed nozzle with a phase angle of 180°. The nozzle material is preferably ceramic to improve the erosion resistance of the nozzle.

[0045] The nozzle 8 is preferably an isochronous deformed nozzle with a phase angle of 180°, and the inner wall surface of the nozzle has been surface-treated to form an approximately fish-scale-like rough inner wall, which can improve the wear and erosion resistance of the nozzle.

[0046] The nozzle cap 9 is arranged at the jet outlet of the nozzle 8, the shock-absorbing layer 10 is arranged between the nozzle cap 9 and the nozzle 8, and the shock-absorbing layer 10 is adhesively connected to the nozzle 8 to reduce the vibration generated by the nozzle during jetting. The erosion-proof cover plate 11 is arranged on the free side of the nozzle cap 9. The erosion-proof cover plate is made of hard alloy to prevent the cutting debris from flowing back and causing erosion damage to the nozzle.

[0047] Both the upper centralizer 2 and the lower centralizer 14 are selected as spiral centralizers to ensure the stability of the oil pipe.

[0048] The magnetic assembly 13 is a combination of an axially magnetized permanent magnetic part and a radially magnetized permanent magnetic part.

[0049] The guide shoe 15 is conical and is connected to the lower centralizer 14 at one end. Its function is to smoothly lower the sandblasting tool into the well and block the lower end of the spray gun.

[0050] The tube body 17 is sleeved on the outside of the spray gun 4. One end of the tube body 17 is provided with a cavity structure, and the electromagnetic component 5 is provided at the cavity structure. The threaded tube 1 is threadedly connected to the cavity structure, and the electromagnetic component 5 is provided inside the threaded tube 1.

[0051] When the device is used for sandblasting and perforating fracturing, magnetic fluid abrasive 16 is added to the fluid inside the spray gun 4 .

[0052] A magnetic focusing hydraulic sandblasting perforation fracturing method is performed using the above-mentioned device through the following steps:

[0053] S1: Use the oil pipe to lower the device and the cable connected to the electromagnet 5 into the construction target reservoir;

[0054] S2: The mixed suspended magnetic fluid abrasive 16 is pumped into the spiral spray gun 4 through the oil pipe and the deflector 3;

[0055] S3: Turn on the power supply of the electromagnetic assembly 5. When the magnetic fluid abrasive 16 flows through the inner spiral spray gun, the inner spiral channel intensifies the disturbance of the magnetic fluid abrasive 16 within the channel. The magnetic field generated by the electromagnet accelerates the magnetic fluid abrasive 16. By controlling the intensity of the magnetic field, the concentration and speed of the magnetic fluid abrasive 16 can be controlled.

[0056] S4: The magnetic fluid abrasive 16 passes through the nozzle 4 and is focused into a jet stream under the action of the axial uniform magnetic field of the magnetic component 13, impacting and crushing the casing, cement sheath and rock reservoir, completing the perforation of the first perforation layer;

[0057] S5: After the perforation operation is completed, the power is turned off, the magnetic field is removed, and the wellbore is flushed.

[0058] S6: After the well is flushed, the fracturing fluid is pumped into the first perforated layer to complete the sand fracturing of the first target reservoir;

[0059] S7: Move the tubing and send the jetting tool to the next target reservoir area, and repeat the above steps S2-S6 until all target layers are perforated and fracturing completed;

[0060] S8: After the perforation and fracturing operation is completed, the coiled tubing is pulled out from the well and wound onto a large-diameter drum for easy movement to the next reservoir area.

[0061] In the present invention, by adding nano-magnetic fluid, the abrasive is made magnetic, and an electromagnetic device is designed to apply an external magnetic field to the abrasive slurry. By regulating the magnetic field intensity, the movement rate of the magnetic fluid abrasive in the nozzle can be assisted and the jet aggregation degree can be increased, without the need to additionally install a high-pressure pump group. The sandblasting perforation fracturing tool provided by the present invention can be used for staged perforation. One trip string can perform multi-layer staged perforation simultaneously, reducing construction costs; the present invention does not require a packer or a bridge plug for mechanical sealing, and automatically seals with high-pressure hydrodynamic force, and can continuously perform multiple fracturing operations, reducing the probability of sand sticking; the internal flow channel of the spray gun of the present invention is set as an internal spiral channel, the nozzle structure and material are optimized, and the service life of the nozzle is increased, so as to achieve fracturing for enhanced production and injection, and improve the perforation accuracy and staged fracturing efficiency.

[0062] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A magnetic focusing hydraulic sandblasting perforation and fracturing device, characterized in that It includes a pipe body (17), inside which a spray gun (4) is arranged, and an electromagnetic component (5) is sleeved on the spray gun (4); when the electromagnetic component (5) is powered on, the electromagnetic component (5) generates a first magnetic field consistent with the axial direction of the spray gun (4). A plurality of nozzles (8) are arranged on the side wall of the spray gun (4); a magnetic component (13) is arranged at one end of the nozzle (8) connected to the spray gun (4); the magnetic component (13) generates a second magnetic field consistent with the axial direction of the nozzle (8). The inside of the spray gun (4) is used for arranging magnetic fluid abrasive (16). The inside of the pipe body (17) includes a first cavity part (171) and a second cavity part (172), the electromagnetic component (5) is arranged in the first cavity part (171), and the plurality of nozzles (8) are arranged in the second cavity part (172). The first cavity part (171) is provided with a threaded pipe (1), the inner wall of the first cavity part (171) is provided with internal threads, the outer wall of the threaded pipe (1) is provided with external threads, and the first cavity part (171) is threadedly connected with the threaded pipe (1); the electromagnetic component (5) is arranged inside the threaded pipe (1). The inner wall of the nozzle (8) is a fish-scale structure. The magnetic fluid abrasive (16) is magnetic nanoparticles.

2. The magnetically focused hydraulic sandblasting perforation fracturing device according to claim 1, wherein A plurality of nozzle supports (7) are arranged at intervals along the axial direction of the second cavity part (172); the plurality of nozzles (8) are arranged inside the plurality of nozzle supports (7).

3. The magnetically focused hydraulic sandblasting perforating and fracturing device according to claim 1, wherein Internal threads (6) are arranged on the inner wall of the spray gun (4).

4. A magnetic focusing hydraulic sandblasting perforation fracturing device according to claim 1, characterized in that A flow guide member (3) is arranged at one end of the spray gun (4) connected to an oil pipe, and the flow guide member (3) is threadedly connected with the spray gun (4).

5. A magnetic focusing hydraulic sandblasting perforating and fracturing device according to claim 1, characterized in that, The magnetic component (13) is a combination of an axially magnetized permanent magnet and a radially magnetized permanent magnet.

6. A magnetic focusing hydraulic sandblasting perforation fracturing device according to claim 1, characterized in that, The magnetic component (13) is made of neodymium iron boron.

7. A magnetic focusing hydraulic sandblasting perforation and fracturing method, characterized in that, Using the magnetic force focused hydraulic sandblasting perforation fracturing device according to any one of claims 1-6, it is carried out through the following steps: S1: Lower the magnetic force focused hydraulic sandblasting perforation fracturing device into the construction target reservoir. S2: Pump magnetic fluid abrasive (16) into the spray gun (4). S3: Power on the electromagnetic component (5), the electromagnetic component (5) generates a magnetic field consistent with the axial direction of the spray gun (4), when the magnetic fluid abrasive (16) flows through the spray gun (4), the first magnetic field pushes the magnetic fluid abrasive (16) to accelerate and transmit inside the spray gun (4). S4: When the magnetic fluid abrasive (16) flows through the nozzle (8), under the action of the second magnetic field generated by the magnetic component (13), the jet flow beam is focused, and the perforation fracturing process of this perforation layer is completed.

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