Slurry sediment purification method and device

Abstract

The invention relates to a mud sediment purification method and device, and belongs to the technical field of mud sediment purification. By adding a gel breaker and combining oxidation / acidolysis and thermochemical treatment, stable structures of colloidal particles are destroyed, wrapped fine particles are released, and a surfactant is further added in a partitioned manner by adopting a spiral path, so that the mud sediment purification effect is improved. And stirring is combined to ensure uniform diffusion of the agent, obviously reduce apparent viscosity of the slurry and improve fluidity. Afterwards, the centrifugal-shear synergistic effect of the high-speed centrifugal machine and the hydrocyclone is used for enhancing the particle separation efficiency, shortening the retention time and inhibiting the laminar flow blockage risk; meanwhile, an electric field is applied to drive charged particles to be enriched towards an electrode area. Finally, the water content of the slurry is greatly reduced through a deep dehydration process assisted by a filter aid, and the integrated process not only reduces the hydrodynamic resistance and treats volume expansion, but also remarkably relieves the problems of laminar flow retardation, abrasion and frequent blockage of pipelines and equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of mud sediment purification, and particularly relates to a mud sediment purification method and device. Background Art

[0002] As a key link in the fields of oil drilling, mine exploitation, and engineering construction, etc., the treatment efficiency of mud sediment directly determines the resource recovery rate, the service life of equipment, and the level of environmental protection cost control. The current mainstream technologies mainly rely on a triple process system of mechanical separation, chemical flocculation, and centrifugal dewatering: First, primary screening is carried out through a vibrating screen or a hydrocyclone to remove large particle solids; Subsequently, a flocculant is added to promote the aggregation of fine particles into clusters for sedimentation separation; Finally, a plate and frame filter press or a centrifuge is used for pressure filtration and dewatering to reduce the moisture content.

[0003] However, when facing complex-component mud with high oil content and strong colloidal stability, the existing technical system faces significant challenges - the stable dispersion system formed by colloidal particles in the mud due to the surface charge repulsion effect and the hydration layer protection effect, under the synergistic action of the oil phase wrapping and the high-viscosity medium, causes it difficult for the conventional flocculation process to effectively destroy the colloidal protection layer, resulting in the hindrance of the release of fine particles and low aggregation efficiency. At the same time, the high-viscosity characteristics lead to the deterioration of hydrodynamics, not only causing the treatment volume to expand, but also forming a laminar flow blockage effect in the pipeline system and separation equipment. The resulting problems of accelerated equipment wear rate and frequent blockage significantly push up the operation and maintenance costs. In view of this technical bottleneck, it is urgent to develop a new mud sediment purification method and device. Summary of the Invention

[0004] To solve the above problems existing in the prior art, the present invention provides a mud sediment purification method and device, which solves the problems in the prior art that high-viscosity mud easily causes the deterioration of hydrodynamics, not only expanding the treatment volume, but also forming a laminar flow blockage effect in the pipeline system and separation equipment, thereby resulting in an accelerated equipment wear rate and frequent blockage problems.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] A mud sediment purification method includes the following steps:

[0007] S1: First, destroy the colloidal stable structure, add a demulsifier, oxidize or acidify the organic matter or hydration layer on the surface of the colloid, adjust the pH to the isoelectric point to neutralize the surface charge of the particles, and then perform thermochemical treatment to promote the destabilization of the particles, disintegrate the colloidal protection layer, and release the encapsulated fine particles;

[0008] S2: Take an appropriate amount of mud sample from S1, place it in an environment with a known magnetic field intensity, and determine whether it has magnetism by observing whether the particles move towards the magnetic field direction. If the particles are magnetic, first add an inorganic flocculant to neutralize the charge, and then add a polymer flocculant to form large flocs through "bridging effect". If the particles are non-magnetic, add magnetite powder as a magnetic seed to copolymerize with the particles;

[0009] S3: Reduce the mud viscosity. From the edge of the mud pit to the center of the mud pit as the direction, divide the mud pit into the first annular region, the second annular region until the Nth annular region in concentric circles in sequence, and add surfactants to the first annular region, the second annular region until the Nth annular region respectively along a spiral path;

[0010] S4: Use a high-speed centrifuge and a hydrocyclone to separate particles through the synergistic action of shear force and centrifugal force;

[0011] S5: Apply an electric field to the charged particles to drive the particles to migrate directionally to the electrode region for aggregation through the electric field;

[0012] S6: Conduct filtration, and then use a pressure filtration device for deep dehydration.

[0013] As a further solution of the present invention, for each circular region of the first annular region, the second annular region until the Nth annular region in S3, the volume V i decreases with the decrease of the radius and decreases according to a quadratic function.

[0014] As a further solution of the present invention, after reducing the mud viscosity in S3, it is also necessary to heat up to improve the fluidity by utilizing the negative correlation between temperature and viscosity again.

[0015] As a further solution of the present invention, when adding surfactants to the first annular region, the second annular region until the Nth annular region respectively along a spiral path in S3, it is necessary to use a stirrer for radial and tangential stirring simultaneously.

[0016] As a further solution of the present invention, after adding surfactants to each annular region in S3, let it stand for a period of time to allow the surfactant to diffuse preliminarily, and before entering the next circle, detect the viscosity of the current region and dynamically adjust the subsequent addition amount.

[0017] As a further solution of the present invention, the volume of the Nth annular region in S3 is the smallest, and the addition amount needs to be reduced by 10% - 15%.

[0018] A mud sediment purification device includes a support cylinder, a mud-water separation component, a concentration and dehydration component, and a purification and recovery component respectively arranged in the support cylinder. The mud-water separation component, the concentration and dehydration component, and the purification and recovery component are arranged from top to bottom in the support cylinder.

[0019] As a further solution of the present invention, the mud-water separation component, the concentration and dehydration component, and the purification and recovery component all include filter meshes. The mesh holes of the filter meshes in the mud-water separation component, the concentration and dehydration component, and the purification and recovery component decrease in sequence, and the mesh holes on adjacent two filter meshes are arranged in a staggered manner.

[0020] As a further solution of the present invention, the mesh holes of the filter meshes in the mud-water separation component, the concentration and dehydration component, and the purification and recovery component are of a positive funnel structure.

[0021] The beneficial effects of the present invention are as follows:

[0022] The separation problem of high-viscosity mud is effectively solved through multi-step collaborative treatment. First, a gel breaker is added and combined with oxidation / acidolysis and thermochemical treatment to destroy the stable structure of colloidal particles and release the encapsulated fine particles. Subsequently, the magnetism of the particles is determined through magnetic field testing. If magnetic, inorganic coagulants and polymer flocculants are added to promote flocculation. If non-magnetic, magnetite powder is introduced as a magnetic seed to achieve copolymerization. Further, a surfactant is added in a spiral path partition manner, and stirring is combined to ensure uniform diffusion of the agent, significantly reducing the apparent viscosity of the mud and improving its fluidity. Thereafter, the centrifugal-shear synergistic effect of a high-speed centrifuge and a hydrocyclone is utilized to enhance the particle separation efficiency, shorten the residence time, and inhibit the risk of laminar flow blockage. At the same time, an electric field is applied to drive charged particles to enrich in the electrode region. Finally, through a deep dehydration process assisted by a filter aid, a significant reduction in the water content of the mud is achieved. This integrated process not only reduces the hydrodynamic resistance and the expansion of the treatment volume but also significantly alleviates the problems of laminar flow blockage, wear, and frequent blockage of pipelines and equipment. Description of the Drawings

[0023] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the drawings.

[0024] Figure 1 It is a flow chart of the mud sediment purification method of the present invention. Detailed Embodiments

[0025] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in conjunction with the drawings and preferred embodiments, details the specific embodiments, structures, features, and their effects according to the present invention are described in detail as follows.

[0026] Please refer to Figure 1 , this embodiment provides a mud sediment purification method, including the following steps:

[0027] S1: First, disrupt the stable structure of the colloid. Add a gel breaker to oxidize or acidolyze the organic matter or hydration layer on the surface of the colloid, adjust the pH to the isoelectric point to neutralize the charge on the particle surface, and then perform thermochemical treatment. Heat to 60–80 °C to reduce the colloid stability, promote particle destabilization, disintegrate the colloid protection layer, and release the encapsulated fine particles. By doing so, the charge on the particle surface can be neutralized, the stability of the colloid can be reduced, thereby reducing the mutual repulsion force between particles, making it easier for particles to aggregate and form flocs. This helps reduce the viscosity of the slurry and prevent the formation of laminar flow blockage effects in pipelines and equipment;

[0028] S2: Take an appropriate amount of slurry sample from S1 and place it in an environment with a known magnetic field strength. Determine whether it has magnetism by observing whether the particles move towards the magnetic field direction. If the particles are magnetic, first add an inorganic flocculant to neutralize the charge, and then add a polymer flocculant to form large flocs through "bridging action". If the particles are non-magnetic, add magnetite powder as a magnetic seed to copolymerize with the particles; convert micron-sized particles into millimeter-sized flocs, increase the sedimentation rate, reduce the residence time of the slurry in the pipeline, and reduce the risk of laminar flow;

[0029] S3: Reduce the slurry viscosity. Add a surfactant to disrupt the internal structure of the slurry and reduce the apparent viscosity. Divide the slurry pond into the first annular region, the second annular region until the Nth annular region in concentric circles from the edge of the slurry pond to the center of the slurry pond, and add the surfactant to the first annular region, the second annular region until the Nth annular region respectively along a spiral path;

[0030] S4: Use a high-speed centrifuge and a hydrocyclone. Compensate for the insufficient density difference through centrifugal force, and use the hydrocyclone to separate particles through the synergistic action of shear force and centrifugal force; improve the separation efficiency, reduce the residence time of the slurry in the equipment, and reduce the risk of laminar flow and blockage;

[0031] S5: Apply an electric field to charged particles to drive the particles to migrate directionally to the electrode region for aggregation through the electric field; this electrophoresis separation technology can further improve the separation efficiency of particles, reduce the content of fine particles in the slurry, thereby reducing the viscosity of the slurry, reducing pipeline blockage and equipment wear;

[0032] S6: Perform filtration, and then use a pressure filtration device for deep dehydration. The pressure filtration device is a plate and frame filter press or a belt filter press. Add a filter aid for deep dehydration, which can effectively remove the water in the slurry, reduce the volume of the slurry, reduce the hydrodynamic problems during the treatment process. At the same time, the slurry after deep dehydration is easier to handle and store, reducing the risk of equipment wear and blockage.

[0033] When faced with complex-component mud with high oil content and strong colloidal stability, the existing technical system faces significant challenges. The stable dispersion system formed by colloidal particles in the mud due to the surface charge repulsion effect and the hydration layer protection effect, under the combined action of the oil phase wrapping and the high-viscosity medium, makes it difficult for conventional flocculation processes to effectively destroy the colloidal protection layer. The release of fine particles is blocked, resulting in low agglomeration efficiency. At the same time, the high-viscosity characteristics lead to the deterioration of hydrodynamics, not only causing the treatment volume to expand, but also forming a laminar flow blockage effect in the pipeline system and separation equipment. The resulting problems of accelerated equipment wear rate and frequent blockages significantly increase the operation and maintenance costs.

[0034] To solve the above problems, this embodiment effectively solves the separation problem of high-viscosity mud through multi-step collaborative processing: First, a demulsifier is added and combined with oxidation / acidolysis and thermochemical treatment to destroy the stable structure of colloidal particles and release the encapsulated fine particles. Subsequently, the magnetic properties of the particles are determined through magnetic field testing. If they are magnetic, inorganic coagulants and polymer flocculants are added to promote flocculation. If they are non-magnetic, magnetite powder is introduced as a magnetic seed to achieve copolymerization. Further, a surfactant is added in a spiral path partition, and stirring is combined to ensure uniform diffusion of the reagent, significantly reducing the apparent viscosity of the mud and improving its fluidity. Thereafter, the centrifugal-shear synergistic action of a high-speed centrifuge and a hydrocyclone is used to enhance the particle separation efficiency, shorten the residence time, and inhibit the risk of laminar flow blockage. At the same time, an electric field is applied to drive charged particles to accumulate in the electrode region. Finally, through a deep dehydration process assisted by a filter aid, a significant reduction in the water content of the mud is achieved. This integrated process not only reduces the hydrodynamic resistance and the expansion of the treatment volume, but also significantly alleviates the laminar flow blockage, wear, and frequent blockage problems in pipelines and equipment.

[0035] It should be noted that when reducing the viscosity of the mud by adding surfactants in S3, the surfactant can reduce the surface tension of the mud, thereby reducing its viscosity. However, if too much surfactant is added, it may cause the mud to be over-diluted, lose its original stability, and affect the subsequent treatment process. The amount of surfactant added needs to match the properties of the mud to ensure the effectiveness and uniformity of the chemical reaction. In this regard, in one embodiment, a method for calculating the amount of surfactant required for the solution of the present application is given: first, use a rheometer or viscometer to measure the viscosity of the mud at different surfactant concentrations, draw a "viscosity-concentration" curve, and obtain the inflection point where the corresponding viscosity decrease rate significantly slows down, which is M. Then, calculate the theoretical amount of surfactant added according to the formula Q theory = V × ρ × M, where V is the volume of the mud, Q theory is the theoretical amount of surfactant added, ρ is the density of the mud, and M is the inflection point where the corresponding viscosity decrease rate significantly slows down. In addition, since the spiral path addition may cause uneven local mixing, it is necessary to determine the correction coefficient through experiments. Simulate the spiral addition process in the laboratory, measure the actual amount of surfactant Q actual required to reach the target viscosity, and calculate the mixing efficiency coefficient: k = Q theory / Q actual. If the stirring is sufficient, k ≈ 1.1 - 1.3; if manually stirred or the path coverage is uneven, k ≈ 1.5 - 2.0; divide the mud pool into N annular regions along the spiral path, and the volume of each region is V i = V / N, then the addition amount for the i-th time: Q i = k × V i × ρ × M × (1 + α(η0 - η)), where η is the target viscosity, η0 is the initial viscosity, and α is the viscosity correction factor, which is used to reflect the non-linear effect of the initial viscosity on the addition amount.

[0036] In order to improve the efficiency and uniformity of the mud sediment purification process and avoid the problems of uneven and excessive use of chemicals, in one embodiment, the volume V of each circular region from the first circular region to the Nth circular region in S3 i decreases with the decrease of the radius and decreases according to a quadratic function. By reducing the viscosity of the mud, the sedimentation speed of the solid particles in the mud can be accelerated, thereby improving the efficiency of the entire purification process. Using a spiral path to add surfactants can ensure that each annular region is evenly treated, effectively reducing the viscosity of the mud in the entire mud pool. Adjusting the surfactant dosage of each circular region according to the law of quadratic function decrease can more precisely control the reaction process, reduce the usage amount of chemical agents, and reduce costs.

[0037] Since it is aimed at high-viscosity mud, considering the influence of the external temperature, it is necessary to reasonably control the temperature of the mud in order to further optimize the fluidity of the mud. In one embodiment, after reducing the viscosity of the mud in S3, it is also necessary to heat it up to 50°C - 70°C. Then, the negative correlation between temperature and viscosity is used again to improve the fluidity. There is a negative correlation between the viscosity and temperature of the mud, that is, as the temperature rises, the viscosity of the mud will decrease. This is because the increase in temperature will cause the molecular movement in the mud to accelerate and the intermolecular force to weaken, making the mud flow more easily. Heating up can accelerate the reaction rate of the chemical additives in the mud, enabling them to play their roles faster and thus more effectively reduce the viscosity of the mud. And when adding surfactants to the first annular region, the second annular region until the Nth annular region respectively along the spiral path in S3, it is necessary to use a stirrer to perform radial and tangential stirring at the same time. The addition method of the spiral path and the radial and tangential stirring ensure the uniform distribution of the surfactant in the mud. In addition, after adding the surfactant to each annular region in S3, let it stand for a period of time to allow the surfactant to initially diffuse. Letting it stand for a period of time to initially diffuse helps to improve its contact efficiency and reaction efficiency with the mud. If it does not stand, the surfactant may not be able to fully contact the mud, thus reducing the purification effect. Since a fixed addition amount may lead to too much or too little surfactant in some areas, affecting the purification effect and cost, therefore, before entering the next circle, detect the viscosity of the current region and dynamically adjust the subsequent addition amount, which can accurately control the dosage of the surfactant and avoid waste. Finally, the volume of the Nth annular region in S3 is the smallest, and the addition amount needs to be reduced by 10% - 15%. The reduction of 10% - 15% can maximize the cost-effectiveness without sacrificing the product performance. The volume of the Nth annular region is the smallest, and reducing the addition amount of the surfactant can reduce the cost and avoid over-treatment.

[0038] A mud sediment purification device includes a support cylinder, a mud-water separation component, a concentration and dehydration component, and a purification and recovery component respectively arranged in the support cylinder. The mud-water separation component, the concentration and dehydration component, and the purification and recovery component are arranged from top to bottom in the support cylinder. The mud-water separation component, the concentration and dehydration component, and the purification and recovery component all include a filter screen. The mesh holes of the filter screens in the mud-water separation component, the concentration and dehydration component, and the purification and recovery component decrease in turn, and the mesh holes on adjacent two filter screens are arranged in a staggered manner. The mesh holes of the filter screens in the mud-water separation component, the concentration and dehydration component, and the purification and recovery component are in a positive funnel structure;

[0039] It is worth mentioning that the mesh holes of the filter screen from the mud-water separation to the concentration and dehydration to the purification and recovery components gradually decrease, forming a three-stage filtration gradient. Large particles are intercepted on the first layer, avoiding direct impact on the subsequent fine mesh and reducing the risk of instantaneous blockage. Different-sized particles are gradually intercepted through physical classification, preventing the fine mesh from being covered by large particles prematurely. In addition, the flow rate of the viscous fluid gradually adapts to the mesh size during progressive filtration, reducing the deterioration of laminar flow caused by sudden pressure changes. At the same time, the wear pressure is shared in stages, extending the service life of each component. In addition, the mesh holes of adjacent filter screens are designed with misalignment, and the mesh holes of adjacent filter screens do not overlap in the vertical direction, forcing the fluid path to change. Local turbulence is induced through path deviation, breaking the laminar flow blockage easily formed by highly viscous fluids and enhancing the internal shear force of the mud. The eddy current generated by the change in fluid direction can scour the edge of the mesh hole, preventing particle jamming, effectively alleviating the "boundary layer thickening" phenomenon of viscous mud, reducing the flow channel resistance, improving the processing efficiency, and reducing the static adhesion probability of particles at the mesh hole, inhibiting blockage from the root of the flow state design. Finally, the filter screen with a positive funnel structure has an inverted conical channel with a larger upper part and a smaller lower part. The intercepted particles are guided to slide down along the funnel wall by gravity and hydrodynamic force, avoiding horizontal retention. The funnel structure forms a local pressure difference, accelerating the fluid passing through the mesh hole and reducing the particle residence time. The conical channel expands the contact area when the particles pass through, reducing the probability of jamming.

[0040] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for purifying mud sediment, characterized in that, It includes the following steps: S1: First, destroy the stable structure of the colloid. Add a gel breaker to oxidize or acidolyze the organic matter or hydration layer on the surface of the colloid, adjust the pH to the isoelectric point to neutralize the charge on the particle surface, and then perform thermochemical treatment to promote the destabilization of the particles, disintegrate the colloid protection layer, and release the encapsulated fine particles; S2: Take an appropriate amount of the slurry sample from S1 and place it in an environment with a known magnetic field strength. Determine whether it has magnetism by observing whether the particles move towards the magnetic field direction. If the particles are magnetic, first add an inorganic flocculant to neutralize the charge, and then add a polymer flocculant to form large flocs through "bridging action". If the particles are non-magnetic, add magnetite powder as a magnetic seed to copolymerize with the particles; S3: Reduce the viscosity of the slurry. From the edge of the slurry pond to the center of the slurry pond, divide the slurry pond into the first annular area, the second annular area until the Nth annular area in concentric circles in sequence, and add surfactants to the first annular area, the second annular area until the Nth annular area respectively along a spiral path; S4: Use a high-speed centrifuge and a hydrocyclone to separate the particles through the synergistic action of shear force and centrifugal force; S5: Apply an electric field to the charged particles and drive the particles to migrate directionally to the electrode area for aggregation through the electric field; S6: Conduct filtration, and then use a pressure filtration device for deep dehydration.

2. A method for purifying mud sediment according to claim 1, characterized in that: The volume V of each circular region of the first circular region, the second circular region, and up to the Nth circular region in S3 i decreases with the decrease of the radius and decreases according to a quadratic function.

3. A method for purifying mud sediment according to claim 1, characterized in that, After reducing the viscosity of the slurry in S3, it is also necessary to heat up and use the negative correlation between temperature and viscosity to improve fluidity again.

4. A method for purifying mud sediment according to claim 1, characterized in that, When adding surfactants to the first annular area, the second annular area until the Nth annular area respectively along a spiral path in S3, it is necessary to use a stirrer to perform radial and tangential stirring simultaneously.

5. A method for purifying mud sediment according to claim 1, characterized in that, After adding surfactants to each annular area in S3, let it stand for a period of time to allow the surfactant to diffuse initially, and before entering the next circle, detect the viscosity of the current area and dynamically adjust the subsequent addition amount.

6. A method for purifying mud sediment according to claim 1, characterized in that: The volume of the Nth annular area in S3 is the smallest, and the addition amount needs to be reduced by 10% - 15%.

7. A mud sediment purification device, based on the mud sediment purification method according to any one of claims 1-6, characterized in that, It includes a support cylinder, a muddy water separation component, a concentration and dehydration component, and a purification and recovery component respectively arranged in the support cylinder. The muddy water separation component, the concentration and dehydration component, and the purification and recovery component are arranged from top to bottom in the support cylinder.

8. The mud sediment purification device according to claim 7, characterized in that, The muddy water separation component, the concentration and dehydration component, and the purification and recovery component all include a filter screen. The mesh holes of the filter screens in the muddy water separation component, the concentration and dehydration component, and the purification and recovery component decrease in sequence, and the mesh holes on adjacent two filter screens are arranged in a staggered manner.

9. The mud sediment purification device according to claim 8, characterized in that, The mesh holes of the filter screens in the muddy water separation component, the concentration and dehydration component, and the purification and recovery component are of a positive funnel structure.

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