CN111410346B - A kind of waste drilling fluid combined treatment device and method - Google Patents

Abstract

The invention belongs to the technical field of drilling fluid treatment, discloses a combined treatment device and method for waste drilling fluid, and solves the problem that the existing waste drilling fluid is poor in separation effect of metal salt ions and micro solid phases. The device comprises an electric adsorption and photocatalysis combined treatment device, wherein the electric adsorption and photocatalysis combined treatment device comprises an electric adsorption box, the left side and the right side of the electric adsorption box are respectively provided with an electrode plate, the electrode plates are respectively communicated with an external power supply, two sides of the electrode plates are respectively sleeved with a clamping plate, the upper end of the electric adsorption box is provided with an ultraviolet lamp tube, and the ultraviolet lamp tube is communicated with the external power supply.

Description

A kind of waste drilling fluid combined treatment device and method

technical field

The invention belongs to the technical field of drilling fluid treatment, and in particular relates to a combined treatment device and method for waste drilling fluid.

Background technique

Drilling fluid is the circulating flushing medium used in the hole during the drilling process. The main functions of the drilling fluid are: 1. Cool the drill bit, clean the bottom of the hole, and bring out the cuttings. ② Lubricate the drill. ③ Suspend cuttings when drilling stops, protect the hole wall from collapse, balance the formation pressure, and suppress the high-pressure oil and gas water layer. ④Conveying the core, and transmitting the power required for breaking the rock at the bottom of the hole for the power machine at the bottom of the hole. The waste drilling fluid is mainly composed of drilling mud, drilling sewage, drilling cuttings and fracturing flowback fluid, etc. It generally shows high COD value, high pH value, and contains a large amount of organic components and inorganic salts in the mud and fracturing fluid. And drilling fluid additives, etc., the pollutant concentration is high, and the treatment is difficult.

In the prior art, the treatment of waste drilling fluid generally adopts centrifugal separation to separate the solid phase in the drilling fluid. The device mainly consists of waste oil-based drilling fluid storage tanks, clean water storage tanks, valves, heating and stirring tanks, demulsifier storage tanks, three-phase cyclone separators, recovered oil storage tanks, sewage recovery tanks, waste sediment solidification tanks and solidification tanks. The waste oil-based drilling fluid storage tank, the clean water storage tank and the demulsifier storage tank are connected to the upper end of the heating and stirring tank through a pipeline, and the bottom end of the heating and stirring tank is equipped with a valve on the pipeline, which is connected to the three-phase rotary At the top of the flow separator, the recovered oil storage tank for recovering oil is connected to the middle of the three-phase cyclone separator, and the sewage recovery tank and waste sediment solidification tank for holding sewage are respectively connected with the lower end of the three-phase cyclone separator. Connected to the bottom end, the bottom end of the sewage recovery tank and the solidifying agent storage tank are respectively connected with the waste sediment solidification tank.

The patent application number 201610566660.5 discloses a solid-liquid separation method for waste water-based drilling fluid in oil and gas fields,

(1) Xinjiang region

In the first stage, the waste water-based drilling fluid of the bentonite system adopts the static settling method, so that the suspended solid phase substances in it are naturally settled to form sludge, and then the filtration method is used to realize the solid-liquid separation;

In the second stage, the polymer system waste water-based drilling fluid, 1m3 of waste water-based drilling fluid is added with flocculant PAC14~15kg, so that the solid phase material coagulates, and then the filtration method is used to filter out the solid phase material to achieve solid-liquid separation;

Three-stage and four-stage polysulfonic system waste water-based drilling fluid, 1m3 of waste water-based drilling fluid is added with flocculant PAC 14-15kg, and coagulant PAM 0.45-0.6kg; the solid phase material in it is coagulated, and then filtered method to filter out the solid phase material to achieve solid-liquid separation;

(2) East Sichuan area

In the first stage, the waste water-based drilling fluid of the bentonite system adopts the static settling method, so that the solid phase material in it is naturally settled to form sludge, and then the filtration method is used to realize the solid-liquid separation;

In the second stage, the polymer system waste water-based drilling fluid, 1m3 of waste water-based drilling fluid is added with flocculant PAC18～20kg, coagulant aid PAM0.05～0.06kg, stabilizer 2～2.5kg, so that the solid phase material in it coagulates , and then use the filtration method to filter out the solid phase material to achieve solid-liquid separation;

Three-stage polysulfonic system waste water-based drilling fluid, 1m3 of waste water-based drilling fluid is added with 30～35kg of compound breaker, 3～4kg of flocculant PAC, 0.05～0.06kg of coagulant aid PAM, and 2～2.5kg of stabilizer kg, the colloidal ions are broken, the liquid phase is released, the solid phase is condensed, and then the solid phase is filtered out by filtration to achieve solid-liquid separation;

(3) Western Sichuan area

In the first stage of the polymer system waste water-based drilling fluid, 1m3 of waste water-based drilling fluid is added with 10-11kg of gel breaker, 3-5kg of flocculant PAC, and 4-6kg of stabilizer to break the colloidal ions and release the liquid phase substances. , the solid phase material is condensed, and then the filtration method is used to filter out the solid phase material to achieve solid-liquid separation;

In the second stage and later stage, the waste water-based drilling fluid of the polysulfonic acid system, 1m3 of waste drilling fluid is added with 20kg breaker, 3~4kg flocculant PAC, and 10~12kg stabilizer to break the colloidal ions, and the liquid phase in it is released and solidified. The phase material is condensed, and then the solid phase material is filtered out by filtration to achieve solid-liquid separation.

The flocculant PAC is polyaluminum chloride, the coagulation aid PAM is polyacrylamide, the stabilizer is calcium oxide, the gel breaker is aluminum sulfate, and the compound gel breaker is aluminum sulfate and The mixture of sulfuric acid, its proportion is 30-35kg of aluminum sulfate: 0.02L of sulfuric acid of 2mol/L.

The coagulation aid PAM is a cationic polyacrylamide with a molecular weight of ≥6 million.

Another example is the invention patent with the application number of 201810283692.3, which discloses a method and application for solid-liquid separation of waste drilling fluid, including three steps of ultrasonic treatment, waste drilling fluid centrifugation, and solid-liquid phase separation. In the water tank of the ultrasonic treatment device, put the ultrasonic treatment vibration plates into the water tank of the ultrasonic treatment device at equal intervals, and ultrasonically treat the waste drilling fluid. The ultrasonic treatment time is 15min~60min respectively, and the ultrasonic treatment frequency is 18kHz~25kHz; Passing the ultrasonically treated waste drilling fluid into a centrifuge, and centrifuging the ultrasonically treated waste drilling fluid, the centrifugal time of the centrifuge is 10min-60min, and the centrifugal speed of the centrifuge is 2000r/min-4000r/min; Solid-liquid phase separation refers to the separation of waste drilling fluid after centrifugation.

As described above in the prior art, the treatment methods for the waste drilling fluid are mainly: solid-liquid separation by chemical treatment and centrifugation.

However, it is difficult to separate the metal salt ions and the micro solid phase in the waste drilling fluid by centrifugation, resulting in poor separation effect of the metal salt ions and the micro solid phase.

SUMMARY OF THE INVENTION

In order to solve the problem of poor separation effect of metal salt ions and tiny solid phases in the existing waste drilling fluid, the present invention provides a waste drilling fluid joint treatment device and method.

For solving the technical problem, the technical scheme adopted in the present invention is:

A combined treatment device for waste drilling fluid is characterized in that it includes an electro-adsorption-photocatalysis combined treatment device, the electro-adsorption-photocatalysis combined device includes an electro-adsorption box, and electrode plates are respectively provided on the left and right sides of the electro-adsorption box, The electrode plates are respectively connected with an external power source, the two sides of the electrode plates are respectively sleeved with splints, and the upper end of the electro-adsorption box is provided with an ultraviolet light tube, which is communicated with the external power source.

Further, a first control box is arranged outside the electro-adsorption box, a first power supply is arranged in the first control box, the first power supply is communicated with the electrode plate, and a first control box is arranged on the first control box for A first power supply controller for controlling the first power supply; a second control box is also arranged outside the electro-adsorption box, and a second power supply is arranged in the second control box, and the second power supply is communicated with the ultraviolet light tube , the second control box is provided with a second power supply controller for controlling the second power supply.

Further, two sides of the electro-adsorption box are respectively provided with a liquid discharge pipe and a liquid inlet pipe, and the liquid inlet pipe is connected with a second circulating pump.

Further, the feed end of the second circulating pump is provided with a filter box, the filter box is provided with a filter screen, the feed end of the second circulation pump is connected to the filter box at the lower end of the filter screen, the The filter box at the upper end of the filter screen is communicated with the waste drilling fluid through a pipeline and a first circulating pump.

A method for the joint treatment of waste drilling fluid, characterized in that it comprises a joint treatment device for waste drilling fluid, and the treatment of the waste drilling fluid by the joint treatment device for waste drilling fluid comprises the following steps:

(1) Preprocessing;

(2) filtering;

(3) Electrosorption and photocatalytic treatment.

Further, the pretreatment includes adding polyaluminum chloride to the waste drilling fluid first, and the polyaluminum chloride destabilizes the charge and colloid in the waste drilling fluid to form fine flocs, which are stirred with a stirrer; and then add The polyacrylamide was stirred again, and after stirring, it was left to stand and the supernatant was taken.

Further, the polyaluminum chloride is added in an amount of 8-12g per L of waste drilling fluid, and the polyacrylamide is added in an amount of 8-12g per L of discarded drilling fluid; The stirring time after aluminum chloride is 25-40min, the stirring time after adding polyacrylamide to the waste drilling fluid is 5-6.5h; the stirring time after adding polyacrylamide is 20-30h.

Further, the filtration is to filter out lumps and impurities in the supernatant by using the filter screen in the filter box.

Further, the electrosorption and photocatalytic treatment includes:

(1) The voltage between the two electrode plates in the electro-adsorption box is 20-40v, and the distance between the two electrode plates is 0.8-5cm; the time for applying the voltage to the two electrode plates is 25-60min;

(2) adding TIO ₂ -graphene composite photocatalyst to the supernatant liquid entering the electrosorption box, the addition amount of the TIO ₂ -graphene composite photocatalyst is to add 0.45-0.55mg per L of waste drilling fluid , the wavelength of the ultraviolet light emitted by the ultraviolet light tube is 350-370nm, and the power of the ultraviolet light tube is 10-20w.

Further, the irradiation time of the ultraviolet light tube is 50-70 min.

Compared with the prior art, the present invention has the following beneficial effects:

The waste drilling fluid combined treatment device of the present invention performs combined treatment on the waste drilling fluid through electro-adsorption and photocatalysis. During the treatment process, a voltage is applied between the two electrode plates to form an electric field, which is used to treat the metal salt ions and the metal salt ions in the waste drilling fluid. The micro-solid phase performs effective adsorption, and the adsorbed metal salt ions (Na ⁺ , Mg ²⁺ , Al ³⁺ , Ca ²⁺ , K ⁺ , Hg ²⁺ , Pb ²⁺ , Cu ²⁺ ) and the micro-solid phase stick to It is attached to the splint. When the metal salt ions and tiny lone stars on the splint need to be removed, the splint can be removed to clean it up or put on the splint again for continuous operation. The TIO ₂ -graphene composite photocatalyst is added and irradiated by an ultraviolet light tube. Under the action of ultraviolet light, the electrons in the valence band of TiO ₂ nanoparticles are excited and transition to the conduction band, the photogenerated electrons and holes are separated, and the electron flow Introduced into the graphene sheet structure, the good electrical conductivity of graphene inhibits the recombination probability of holes and electrons, and greatly improves the photocatalytic activity of _TiO2 semiconductors. On the other hand, graphene has a large surface area and abundant ∏-∏ conjugated bonds on the surface, which can adsorb organic substances containing benzene rings onto the surface, providing more photocatalytic sites, thereby increasing the concentration of metal salt ions, micro-solid phase and the adsorption capacity of organic matter. Tests show that the metal salt ion adsorption and removal rate of the present invention is 60-70%, and at the same time, the solid phase particle content in the waste drilling fluid can be reduced from 70% to 54.9-55.3%, thereby greatly improving the efficiency of waste drilling. The adsorption capacity of solid phase particles in drilling fluid; at the same time, it can also reduce the particle size of solid phase particles in waste drilling fluid.

Description of drawings

1 is a schematic structural diagram of an embodiment of the waste drilling fluid combined treatment device of the present invention;

Fig. 2 is the schematic sectional view of Fig. 1;

Fig. 3 is the particle size distribution table of the solid phase particles before being processed by the present invention; the curve on the left side of the graph represents the particle size point, and the curve on the right side represents the cumulative content of the solid phase particles;

Fig. 4 is the particle size distribution table of the solid phase particles after the treatment of the present invention; the curve on the left side of the graph represents the particle size point, and the curve on the right side represents the cumulative content of the solid phase particles;

Labels in the figure: 1, filter box, 2, frame, 3, filter screen, 4, first guide pipe, 5, first circulation pump, 6, first chassis, 7, liquid inlet pipe, 8, second Draft tube, 9, Second circulating pump, 10, Second chassis, 11, Third draft tube, 12, Electrosorption box, 13, Activated carbon fiber cloth, 14, Electrode plate, 15, First control box, 16 , the first power controller, 17, the first wire, 18, the drain pipe, 19, the drain valve, 20, the column, 21, the top plate, 22, the second wire, 23, the second control box, 24, the second Power controller 25, ultraviolet light tube.

Detailed ways

The present invention will be further described below with reference to the embodiments, and the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, other used embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention; the terms "first", "second", "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; furthermore, unless otherwise Clearly stipulated and defined, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or a Electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

With reference to the accompanying drawings, the combined treatment device for waste drilling fluid of the present invention includes an electro-adsorption photocatalysis combined treatment device, and the electro-adsorption photocatalysis combined device includes an electro-adsorption box 12, and the left and right sides of the electro-adsorption box 12 are respectively provided with Electrode plate 14, the electrode plate 14 is respectively connected with the external power supply, the two sides of the electrode plate 14 are respectively sleeved with splints 13, the upper end of the electro-adsorption box 12 is provided with an ultraviolet light tube 25, the ultraviolet light The light bulb 25 is connected to an external power source.

Further, a first control box 15 is arranged outside the electro-adsorption box 12 , a first power supply is arranged in the first control box 15 , the first power supply is communicated with the electrode plate 14 , and the first control box 15 is provided with a first power supply controller 16 for controlling the first power supply; a second control box 23 is also provided outside the electro-adsorption box 12, and a second power supply is arranged in the second control box 23, and the The second power supply is communicated with the ultraviolet light tube 25 , and the second control box 23 is provided with a second power supply controller 24 for controlling the second power supply.

The first control box 15 is used for installing and fixing the first power supply and the first power supply controller 16 , and the second control box 23 is used for installing and fixing the second power supply and the second power supply controller 24 . The first power supply controller and the second power supply controller both belong to the prior art products, which can be understood and understood by those skilled in the art, and will not be repeated here.

In some embodiments, the ultraviolet light tube 25 is connected to the second power controller 24 through the second wire 22 , and the electrode plate 14 is connected to the first power controller 16 through the first wire 17 .

For example, the power supply controller of the present invention adopts the BJW-51 model produced by Tianjin Rongxing Kaisheng Electric Heating Material Co., Ltd. and its related supporting power supply and circuit. The technical parameters of this type of power controller are: voltage 380v, controller temperature of BJW-51 0-200℃.

In some embodiments, the two opposite inner walls of the electro-adsorption box 12 are symmetrically fixed with eight identical clamping plates 13 , each of the two clamping plates 13 is a group, and the four groups of the clamping plates 13 are respectively clamped on The two sides of the two motor boards 14 are convenient for fixing the motor boards 14 . The motor plates 14 on the left and right inner walls of the electro-adsorption box 12 are symmetrically arranged according to the central axis of the electro-adsorption box 12 in the vertical direction.

In some embodiments, the splint 13 is made of activated carbon fiber cloth, and the splint 13 made of activated carbon fiber cloth can not only realize the clamping of the electrode sheet 14, but also facilitate the removal of the electrode sheet 14 from the electro-adsorption box 12 after the electro-adsorption is completed. The adsorbed solid phase and heavy metals are hung on the activated carbon fiber cloth.

In some embodiments, a column 20 is mounted on the upper part of the electro-adsorption box 12 , a top plate 21 is mounted on the upper end of the column 20 , and the ultraviolet light tube 25 is mounted on the top plate 21 , so that the ultraviolet rays emitted by the ultraviolet light tube 25 can affect the electricity The drilling fluid in the adsorption box 12 is irradiated.

Further, two sides of the electro-adsorption box 12 are respectively provided with a liquid discharge pipe 18 and a liquid inlet pipe, and the liquid inlet pipe is connected with a second circulating pump 9 . Among them, the liquid discharge pipe 18 is provided with a liquid discharge valve 19, and the liquid discharge valve 19 is used to control the opening and closing of the liquid discharge pipe 18; The flow pipe 11 communicates with the second circulation pump 9 , that is to say, the liquid inlet pipe of the electro-adsorption tank 12 communicates with the second circulation pump 9 through the third guide pipe 11 .

In some embodiments, the liquid inlet pipeline of the electro-adsorption tank 12 can also be directly communicated with the second circulating pump 9 .

Further, the feed end of the second circulating pump 9 is provided with a filter box 1, and the filter box 1 is provided with a filter screen 3, and the feed end of the second circulating pump 9 is connected to the lower end of the filter screen 3. In the filter box 1 , the filter box 1 at the upper end of the filter screen 3 is communicated with the waste drilling fluid through the pipeline and the first circulating pump 5 . That is to say, the feed end of the second circulating pump 9 is used to communicate with the filter box below the filter screen 3 , and the discharge end of the second circulating pump 9 is used to communicate with the electric adsorption box 12 . Wherein, the size of the mesh of the filter screen 3 determines the aperture of the filter screen. As a preferred method of the present invention, in order to improve the filtering effect of the filter screen 3, the mesh number of the filter screen 3 is 400 meshes (the filter screen aperture is 38 meshes). microns), so that the filter screen can filter out 1-2 microns of solid phase particles, so as to reduce the workload of the subsequent electro-adsorption box 1. The filter screen 3 is convenient for filtering the lumps, industrial waste and part of the solid phase in the drilling fluid.

In some embodiments, the feed end of the second circulation pump 9 is communicated with the second guide pipe 8 , one end of the second guide pipe 8 is communicated with the feed end of the second circulation pump 9 , and the second guide pipe 8 The other end is communicated with the filter box 1 below the filter screen 3.

In some embodiments, a frame body 2 is installed on the upper end of the filter box 1, and the filter screen 3 is installed in the frame body 2, and the filter screen 3 is fixed by the frame body.

In some embodiments, a first guide pipe 4 is installed on the filter box at the upper end of the filter screen 3, the first guide pipe 4 is used for communicating with the first circulating pump 5, and the feed end of the first circulating pump 5 is useful for communicating with In the liquid inlet pipe 7 extending into the waste drilling fluid. In some embodiments, in order to protect the first circulation pump 5 and the second circulation pump 9 in the field, and also to facilitate installation and transportation, the first circulation pump 5 is installed in the first chassis 6, and the second circulation pump 9 Installed in the second chassis 10 .

Among them, the first circulating pump 5 and the second circulating pump 9 belong to the prior art products, which can be understood and understood by those skilled in the art. For example, the first circulating pump 5 and the second circulating pump 9 are made of Co., Ltd. produces the ISG model and its related supporting power supply and circuit.

The description of the circulating pump model of this ISG model is as follows:

ISG50-160(I)A(B) 50----The diameter of the pump inlet and outlet is 50mm, 160----The nominal outer diameter of the impeller is 160mm, I---Flow classification, A---Impeller outer diameter cutting code , ISG-----single-stage single-suction pipeline centrifugal pump.

In order to correspond to the circulating pump of this model, the diameter of the liquid inlet pipe 7 and the liquid discharge pipe 18 is 50 mm. Diameter is 50mm.

The method for joint treatment of waste drilling fluid provided by the present invention includes a joint treatment device for waste drilling fluid. The structure of the joint treatment device for waste drilling fluid has been described above, and will not be repeated here. The treatment of the waste drilling fluid by the waste drilling fluid combined treatment device includes the following steps:

(1) Preprocessing;

(2) filtering;

(3) Electrosorption and photocatalytic treatment.

Further, the pretreatment includes adding polyaluminum chloride (PAC) to the waste drilling fluid first, and the PAC destabilizes the charge and colloid in the waste drilling fluid to form fine flocs, and stirs with a stirrer; Then, polyacrylamide (PAM) was added and the mixture was stirred. After stirring, the mixture was allowed to stand and the supernatant was collected.

Further, the polyaluminum chloride is added in an amount of 8-12g per L of waste drilling fluid, and the polyacrylamide is added in an amount of 8-12g per L of discarded drilling fluid; The stirring time after aluminum chloride is 25-40min, the stirring time after adding polyacrylamide to the waste drilling fluid is 5-6.5h; the stirring time after adding polyacrylamide is 20-30h.

Further, the filtration is to use the filter screen in the filter box to filter out lumps and impurities in the pretreated supernatant.

Further, the electrosorption and photocatalytic treatment includes:

(1) The voltage between the two electrode plates in the electro-adsorption box is 20-40v, and the distance between the two electrode plates is 0.8-5cm; the time for applying the voltage to the two electrode plates is 25-60min;

(2) adding TIO ₂ -graphene composite photocatalyst to the supernatant liquid entering the electrosorption box, the addition amount of the TIO ₂ -graphene composite photocatalyst is to add 0.45-0.55mg per L of waste drilling fluid , the wavelength of the ultraviolet light emitted by the ultraviolet light tube is 350-370nm, and the power of the ultraviolet light tube is 10-20w.

In some embodiments, the TIO ₂ -graphene composite photocatalyst is added in an amount of 0.5 mg per L of waste drilling fluid.

In some embodiments, the adding time of TIO ₂ -graphene composite photocatalyst can be directly added to the supernatant obtained after pretreatment in step (1), or directly added to the first adsorption inward.

Further, the step (3) of the electrosorption and photocatalytic treatment includes: firstly performing the photocatalytic treatment for a period of time, and then performing the photocatalytic treatment and the electrosorption treatment simultaneously for a period of time.

Further, in the step (3), the voltage between the two electrode plates in the electro-adsorption box is 30-36v, and the distance between the two electrode plates is 1-2.5cm; the time for applying the voltage to the two electrode plates for 30-35min. Under this condition, it can not only ensure the best electrosorption effect, but also make the activity of the photocatalyst reach the highest value, thereby improving the adsorption capacity of metal salt ions and tiny solid phases.

Further, the photocatalytic treatment is carried out for 25-35min first, then the photocatalytic treatment and the electrosorption are carried out together for 30-35min, and then the photocatalytic treatment and the electrosorption are carried out at the same time after being treated by an ultraviolet lamp for 25-35min. The photocatalyst and activity are maximized, thereby improving the adsorption capacity of metal salt ions and tiny solid phases.

Further, the irradiation time of the ultraviolet light tube is 50-70 min.

After the waste drilling fluid is pretreated, take a 50ml sample of the supernatant, and use a solid phase content analyzer to conduct an indoor test. It can be measured that the solid phase content in the pretreated supernatant is 70%. The experimental data table after electrosorption and photocatalytic treatment is as follows:

It can be seen intuitively from the above table that the present invention can greatly reduce the solid phase content in the drilling fluid after electrosorption and photocatalytic treatment, and the solid phase particle content can be reduced from the original 70% to 54.9-55.3%.

The solid phase content of the present invention is mainly calculated by the difference method to obtain the adsorption amount of the solid phase particles (that is, the tiny solid phase and heavy metal salt ions) under the corresponding conditions. Before the experiment, the solid phase content analyzer is used to measure the solid phase content. Percentage, after the experiment, the amount of each adsorption (including solid phase particles and heavy metal salt ions) is represented on the activated carbon fiber cloth, dried in an oven, weighed and accumulated, and the solid phase particles, that is, the removal of impurities, can be calculated. , and then calculate the removal rate. Because of this, the function of using the activated carbon fiber cloth for the splint of the present invention can not only play the role of clamping the electrode plate, but at the same time, due to the characteristics of the activated carbon fiber cloth, the adhesion of solid phase particles can be reduced as much as possible, thereby improving the accuracy of measurement. sex.

Before being processed by the device of the present invention, the particle size distribution of the pretreated waste drilling fluid is measured by using a laser particle size analyzer. The measured particle size distribution is shown in FIG. 3 , and the curve on the left side of the graph in FIG. 3 represents the particle size point, and the curve on the right represents the cumulative content of solid phase particles.

The particle size distribution after the treatment of the present invention is shown in FIG. 4 . The curve on the left side of the graph in FIG. 4 represents the particle size point, and the curve on the right side represents the cumulative content of solid phase particles.

It can be seen intuitively from the comparison of Fig. 3 and Fig. 4 that the present invention can reduce the particle size of the solid phase content in the waste drilling fluid, thereby facilitating the recycling of the waste drilling fluid in subsequent processing, and solving the problem of waste drilling fluid in the existing The problem that the drilling fluid cannot be reprocessed and recycled because the particle size of the solid phase content is not up to standard.

To sum up, the waste drilling fluid joint treatment device of the present invention performs combined treatment of waste drilling fluid through electro-adsorption and photocatalysis. During the treatment process, a voltage is applied between two electrode plates to form an electric field, which is used to treat the metals in the waste drilling fluid. The salt ions and the micro solid phase are effectively adsorbed, and the adsorbed metal salt ions (Na ⁺ , Mg ²⁺ , Al ³⁺ , Ca ²⁺ , K ⁺ , Hg ^{2 +} , Pb ²⁺ , Cu ²⁺ ) and micro The solid phase adheres to the splint. When it is necessary to remove the metal salt ions and tiny lone stars on the splint, the splint can be removed to clean it up or put on the splint again for continuous operation. The TIO ₂ -graphene composite photocatalyst is added to the drilling fluid and irradiated by an ultraviolet light tube. Under the action of ultraviolet light, the electrons in the valence band of TiO ₂ nanoparticles are excited and transition to the conduction band, and the photogenerated electrons and holes are separated. , the electron flow is introduced into the graphene sheet structure, and the good electrical conductivity of graphene inhibits the recombination probability of holes and electrons, which greatly improves the photocatalytic activity of TiO ₂ semiconductors. On the other hand, graphene has a large surface area and abundant ∏-∏ conjugated bonds on the surface, which can adsorb organic substances containing benzene rings onto the surface, providing more photocatalytic sites, thereby increasing the concentration of metal salt ions, micro-solid phase And the adsorption capacity of organic matter, after testing, the metal salt ion adsorption and removal rate of the present invention is 60-70%. Due to the high content, the waste drilling fluid cannot be recycled and reused. At the same time, the solid phase content in the waste drilling fluid can be reduced from 70% to 54.9-55.3%, which greatly improves the efficiency of the waste drilling fluid. The adsorption capacity of solid phase particle content; at the same time, it can also reduce the particle size of solid phase particles in the waste drilling fluid.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form or substance. It should be pointed out that those of ordinary skill in the art can make Several improvements and supplements should also be regarded as the protection scope of the present invention. All those skilled in the art, without departing from the spirit and scope of the present invention, can utilize the above-disclosed technical content to make some changes, modifications and equivalent changes of evolution, all belong to the present invention. Equivalent embodiments; at the same time, any modification, modification and evolution of any equivalent changes made to the above embodiments according to the essential technology of the present invention still fall within the scope of the technical solutions of the present invention.

Claims (8)

1. a waste drilling fluid combined treatment method, is characterized in that, comprises a waste drilling fluid combined treatment device, the waste drilling fluid combined treatment device comprises an electro-adsorption photocatalysis combined treatment device, and the electro-absorption photocatalysis combined device includes an electro-absorption photocatalysis combined device. The adsorption box, the left and right sides of the electro-adsorption box are respectively provided with electrode plates, the electrode plates are respectively connected with the external power supply, the two sides of the electrode plates are respectively sleeved with splints, and the upper end of the electro-adsorption box is provided with There is an ultraviolet light tube, and the ultraviolet light tube is connected with an external power supply; The treatment of the waste drilling fluid by the waste drilling fluid combined treatment device includes the following steps: (1) preprocessing; (2) filtering; (3) Electro-adsorption and photo-catalytic treatment; the electro-adsorption and photo-catalytic treatment includes: first photocatalytic treatment for a period of time, and then photo-catalytic treatment and electro-adsorption treatment for a period of time; the voltage between the two electrode plates in the electro-adsorption box is 20-40v, the distance between the two electrode plates is 0.8-5cm; the time for applying voltage to the two electrode plates is 25-60min; TIO ₂ -graphene composite is added to the supernatant entering the electrosorption box The photocatalyst, the TIO ₂ -graphene composite photocatalyst is added in an amount of 0.45-0.55 mg per L of waste drilling fluid, and the wavelength of the ultraviolet light emitted by the ultraviolet light tube is 350-370 nm, and the ultraviolet light The power of the lamp is 10-20w. 2. The method for combined treatment of waste drilling fluid according to claim 1, wherein the pretreatment comprises adding polyaluminum chloride to the waste drilling fluid first, and the polyaluminum chloride will remove the charge and colloid in the waste drilling fluid. Destabilize to form fine flocs, and stir with a stirrer; then add polyacrylamide and stir again, let it stand after stirring, and then take the supernatant. 3. The method for joint treatment of waste drilling fluid according to claim 2, wherein the addition of the polyaluminum chloride is 8-12 g per L of the waste drilling fluid, and the addition of the polyacrylamide is Add 8-12g per L of waste drilling fluid; add polyaluminum chloride to the waste drilling fluid and stir for 25-40min; add polyacrylamide to the waste drilling fluid for 5-6.5h; add polyacrylamide to stir The resting time is 20-30h. 4 . The method for joint treatment of waste drilling fluid according to claim 1 , wherein the filtering is to filter out lumps and impurities in the supernatant by using a filter screen in a filter box. 5 . 5. waste drilling fluid combined treatment method according to claim 1, is characterized in that, the irradiation time of described ultraviolet light tube is 50-70min. 6 . The method for combined treatment of waste drilling fluid according to claim 1 , wherein a first control box is arranged outside the electro-adsorption box, a first power supply is arranged in the first control box, and the first control box is arranged in the first control box. 7 . A power supply is communicated with the electrode plate, and a first power supply controller for controlling the first power supply is arranged on the first control box; a second control box is also arranged outside the electro-adsorption box, and the second control box is arranged inside the second control box. A second power supply is provided, the second power supply is communicated with the ultraviolet light tube, and a second power supply controller for controlling the second power supply is arranged on the second control box. 7 . The method for joint treatment of waste drilling fluid according to claim 6 , wherein a liquid discharge pipe and a liquid inlet pipe are respectively provided on both sides of the electric adsorption tank, and the liquid inlet pipe is connected with a second circulating pump. 8 . . 8 . The method for joint treatment of waste drilling fluid according to claim 7 , wherein a filter box is arranged at the feed end of the second circulating pump, and a filter screen is arranged in the filter box. The feeding end of the pump is communicated with the filter box at the lower end of the filter screen, and the filter box at the upper end of the filter screen is communicated with the waste drilling fluid through the pipeline and the first circulating pump.

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