An online mixing device for dry powder fracturing fluid

Abstract

The utility model relates to a kind of dry powder fracturing fluid online mixing device, belong to oilfield chemical auxiliary agent mixing equipment technical field, to solve the problem of existing dry powder mixing device easy to produce fisheye particle, low mixing efficiency, cavity easy residual blockage. The device includes a mixing cavity, a circle annular spray pipe is arranged in the dry powder feed inlet of the top of mixing cavity just below, to form annular water curtain to the dry powder that falls and carry out pre-wetting;Dry powder is forced to disperse before entering vortex mixing area formed by tangential main water inlet, effectively avoid the formation of "fisheye". Preferably, the bottom of mixing cavity is designed as conical closing structure, can eliminate flow dead angle, ensure that viscous fracturing fluid is discharged smoothly. The device improves the dissolution efficiency of dry powder by first pre-wetting and then main mixing two-step method, ensures the quality of fracturing fluid, and the structure is simple, not easy to block, and practicality is strong.

Description

Technical Field

[0001] This utility model relates to the technical field of oilfield chemical additive mixing equipment, specifically to a device for online mixing of dry powder polymers with water to prepare fracturing fluid. Background Technology In fracturing operations during oil and gas field development, fracturing fluid is a crucial working fluid, typically composed of a mixture of water and dry powder polymers such as guar gum. Online mixing units are the core equipment for the real-time, continuous preparation of this fracturing fluid at the work site.

[0002] Existing dry powder mixing devices typically employ Venturi jetting or simple stirring methods, directly introducing the dry powder into a high-speed water flow. In this mixing method, once the dry powder (especially high-molecular polymers) comes into contact with water, a gel film rapidly forms on the surface of the particles, encapsulating the internal dry powder and forming insoluble, fish-eye-shaped particles. These fish-eye particles not only waste dry powder and reduce the performance of the fracturing fluid, but also easily clog subsequent pipelines and equipment, posing safety hazards to fracturing operations. Furthermore, the mixed fracturing fluid usually has a high viscosity, and traditional flat-bottomed or round-bottomed mixing chambers easily create dead zones, leading to residual and deteriorated fluid, affecting subsequent production and making cleaning difficult. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the defects of existing mixing devices, such as the easy generation of fish-eye particles when dry powder comes into contact with water, low mixing efficiency, and easy residue and blockage of viscous liquid due to unreasonable cavity structure. The present invention provides an online mixing device for dry powder fracturing fluid that can avoid the generation of fish-eye particles from the source, mix evenly, and leave no residue and blockage.

[0004] To solve the above-mentioned technical problems, this online dry powder fracturing fluid mixing device includes a mixing chamber, a dry powder inlet located at the top of the mixing chamber, a liquid outlet located at the bottom of the mixing chamber, and a main water inlet located on the side wall of the mixing chamber; wherein, an annular spray pipe is also fixed in the mixing chamber, and the annular spray pipe is located directly below the dry powder inlet; the annular spray pipe has several nozzles that spray water toward the center of the chamber to form an annular water curtain.

[0005] Furthermore, the main water inlet extends into the mixing chamber and is arranged tangentially along the inner wall of the mixing chamber.

[0006] Furthermore, the annular spray pipe is connected to an external water source through a separate spray inlet.

[0007] Furthermore, the lower part of the mixing chamber is a conical constriction structure, the liquid outlet is located at the bottom end of the conical constriction structure, and a discharge valve is provided at the liquid outlet.

[0008] Furthermore, the dry powder inlet is connected to a hopper for feeding dry powder.

[0009] Furthermore, the dry powder inlet is connected to a screw conveyor for quantitatively conveying the dry powder.

[0010] This invention relates to an online mixing device for dry powder fracturing fluid, which overcomes the shortcomings of existing mixing devices, such as the easy formation of fish-eye particles when dry powder comes into contact with water, low mixing efficiency, and easy residue and blockage of viscous liquid due to unreasonable cavity structure. By pre-wetting before main mixing, it improves the dissolution efficiency of dry powder, ensures the quality of fracturing fluid, and has a simple structure that is not prone to clogging. Attached Figure Description

[0011] The following description, in conjunction with the accompanying drawings, further illustrates the online mixing device for dry powder fracturing fluid according to this utility model: Figure 1 This is a schematic diagram of the main plan view of the online mixing device for dry powder fracturing fluid; Figure 2 yes Figure 1 The right view; Figure 3 This is a three-dimensional schematic diagram of the online mixing device for dry powder fracturing fluid; Figure 4 yes Figure 2 Sectional view along axis AA; Figure 5 This is a reference diagram showing one usage state of the online mixing device for dry powder fracturing fluid; Figure 6 This is a reference diagram showing another usage state of the online mixing device for dry powder fracturing fluid.

[0012] In the picture: 1-Mixing chamber; 11-Dry powder inlet; 12-Liquid outlet; 13-Main water inlet; 101-Conical constriction structure; 121-Discharge valve; 2- Annular spray pipe; 21- Nozzle; 22- Spray inlet; 3-Hopper; 4-Screw conveyor. Detailed Implementation

[0013] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0014] In the description of this utility model, it should be understood that the terms "left", "right", "front", "rear", "top", "bottom", "inner", "outer", 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 utility model 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 utility model.

[0015] The present invention will be further described below with specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0016] Implementation method 1: such as Figures 1 to 4 As shown, this online dry powder fracturing fluid mixing device consists of a vertically installed mixing chamber 1. The mixing chamber 1 has a dry powder inlet 11 at the top, a liquid outlet 12 at the bottom, and a main water inlet 13 on the side wall. Inside the mixing chamber 1, directly below the dry powder inlet 11, a ring-shaped spray pipe 2 is coaxially fixed. This ring-shaped spray pipe 2 is fixed to the inner wall of the chamber by multiple connecting rods. Several nozzles 21 are evenly distributed on the ring-shaped spray pipe 2, with all nozzles 21 spraying towards the central axis of the chamber. When the dry powder falls from the dry powder inlet 11, it must first pass through the 360° annular water curtain sprayed by the nozzles 21. The surface of the dry powder particles is forcibly and uniformly wetted, forming a thin water film. After pre-wetting, the powder particles with water on their surface, due to the change in surface properties, are no longer prone to sticking together, providing an effective basis for subsequent full dispersion and dissolution, thus avoiding the formation of fisheyes.

[0017] Implementation method 2: such as Figure 4As shown, the main inlet 13 of this dry powder fracturing fluid online mixing device extends into the mixing chamber 1 and is arranged tangentially to the inner wall of the chamber. The high-speed water flow entering from this inlet forms a strong rotating vortex within the cylindrical chamber, providing powerful mechanical stirring and shearing force for the main mixing stage, allowing the pre-wetted powder to be quickly and thoroughly dispersed. Simultaneously, the lower part of the mixing chamber 1 is designed as a downward-contracting conical structure 101. This funnel-shaped design effectively avoids dead zones caused by flat-bottomed structures, guiding the high-viscosity mixed liquid smoothly towards the central liquid outlet 12, ensuring thorough discharge without residue. A discharge valve 121 is also provided at the liquid outlet 12 to control the discharge of materials. To achieve precise process control, the annular spray pipe 2 is connected to an external water source through an independent spray inlet 22, and its pipeline can be equipped with an independent control valve (not shown in the figure), thereby enabling independent adjustment of the pre-wetting water volume and the main mixing water volume. The remaining structures and components are as described in Embodiment 1 and will not be described again.

[0018] Implementation method 3: such as Figure 5 As shown, a simple hopper 3 is connected to the dry powder inlet 11 of this online dry powder fracturing fluid mixing device. This method is suitable for small-batch, intermittent operations or operations requiring manual feeding, and has the advantages of simple equipment and low cost. The remaining structures and components are as described in Embodiment 2 and will not be described again.

[0019] Implementation method 4: such as Figure 6 As shown: A screw conveyor 4 is connected to the dry powder inlet 11 of this online dry powder fracturing fluid mixing device. The screw conveyor 4 enables continuous, stable, and quantitative supply of dry powder, suitable for industrial applications requiring large-scale, automated continuous production, and can ensure the accuracy and stability of the fracturing fluid ratio. The remaining structures and components are as described in Embodiment 2 and will not be repeated. In use: First, simultaneously open the valves of the main water inlet 13 and the spray water inlet 22 to supply water into the mixing chamber 1. The water from the main water inlet 13 forms a high-speed rotating vortex within the chamber; simultaneously, the water from the spray water inlet 22 passes through the nozzles 21 of the annular spray pipe 2, forming a stable and continuous 360° annular water curtain at the top of the chamber. Then, dry powder is fed into the dry powder inlet 11 through the hopper 3 or the screw conveyor 4. Before contacting the main vortex below, the falling dry powder must first pass through this annular water curtain. At this instant, the surface of each dry powder particle is forcibly and uniformly wetted. These pre-wetted powder particles continue to fall into the vortex mixing zone below, where they are rapidly and thoroughly dispersed and dissolved under the enormous shear force of the vortex, thus preventing the formation of fish eyes. The mixed high-viscosity fracturing fluid, under the combined action of gravity and eddy current, flows along the smooth conical constriction structure 101 and collects at the liquid outlet 12 at the bottom. It can then be smoothly discharged by opening the discharge valve 121.

[0020] This online dry powder fracturing fluid mixing device improves the dissolution efficiency of the dry powder and ensures the quality of the fracturing fluid by pre-wetting before main mixing. It also features a simple structure and is less prone to clogging. Specifically, (1) By setting an annular water curtain below the dry powder inlet, the falling dry powder is pre-wetted, so that a water film is formed on the surface of each powder before entering the vortex of the main mixing zone, thereby avoiding the possibility of powder clumping and fish eyes, and greatly improving the mixing efficiency and solubility.

[0021] (2) The conical bottom design utilizes gravity to guide the high-viscosity mixed liquid to flow smoothly to the central outlet, completely eliminating the dead flow corner at the bottom of the cavity, avoiding material residue and blockage, and ensuring the cleanliness and continuous stable operation of the device.

[0022] (3) The pre-wetting water circuit and the main mixing water circuit can be separated, and the flow rate can be adjusted independently through their respective valves to optimize the process parameters, making it more applicable.

[0023] The above description illustrates the main features, basic principles, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments or examples described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the above embodiments or examples should be considered exemplary and not restrictive. The scope of this utility model is defined by the appended claims rather than the foregoing description, and therefore all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0024] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An online mixing device for dry powder fracturing fluid, characterized in that: It includes a mixing chamber (1), a dry powder inlet (11) located at the top of the mixing chamber (1), a liquid outlet (12) located at the bottom of the mixing chamber (1), and a main water inlet (13) located on the side wall of the mixing chamber (1); wherein, The mixing chamber (1) is also fixed with an annular spray pipe (2), which is located directly below the dry powder inlet (11); the annular spray pipe (2) has several nozzles (21) that spray water toward the center of the chamber to form an annular water curtain.

2. The online mixing device for dry powder fracturing fluid according to claim 1, characterized in that: The main water inlet (13) extends into the mixing chamber (1) and is arranged tangentially along the inner wall of the mixing chamber (1).

3. The online mixing device for dry powder fracturing fluid according to claim 2, characterized in that: The annular spray pipe (2) is connected to an external water source through an independent spray inlet (22).

4. The online mixing device for dry powder fracturing fluid according to claim 3, characterized in that: The lower part of the mixing chamber (1) is a conical constriction structure (101), the liquid outlet (12) is located at the bottom end of the conical constriction structure (101), and a discharge valve (121) is provided at the liquid outlet (12).

5. The online mixing device for dry powder fracturing fluid according to claim 4, characterized in that: The dry powder inlet (11) is connected to a hopper (3) for feeding dry powder.

6. The online mixing device for dry powder fracturing fluid according to claim 4, characterized in that: The dry powder inlet (11) is connected to a screw conveyor (4) for quantitative conveying of dry powder.

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