CN111946278A - Harmless treatment method for geological core drilling waste flushing fluid - Google Patents

Abstract

The invention discloses a technical method for the harmless treatment of waste flushing fluid in geological core drilling, comprising the following contents: adding a gel breaking agent to the waste flushing fluid with a moisture content of ≥85%, stirring evenly, adding flocculation reagent and A coagulation aid agent, the coagulation aid agent includes hydrophilic nano-silica and talc; then solid-liquid separation is performed, an oxidizing agent is added to the separated liquid phase for oxidative decolorization treatment, and then discharged directly, and the separated solid phase is discharged directly. After adding curing agent, it is cured and formed. The harmless treatment method of the waste flushing liquid provided by the present invention greatly reduces the pollution indicators (such as COD, chromaticity, suspended solids, etc.) in the liquid phase after treatment, and the solid after solidification has high strength and reduces environmental pollution, and is especially suitable for It is suitable for the treatment of waste flushing fluid from geological drilling with high water content of pollutants, small particle size of solid particles of pollutants and high colloid rate.

Description

A harmless treatment method for waste flushing fluid from geological core drilling

technical field

The invention relates to the technical field of geological core drilling, in particular to a technical method for the harmless treatment of waste flushing fluid in geological core drilling.

Background technique

Waste flushing fluid is a kind of clay, chemical additives (various glue protection agents, fluid loss reducers, lubricants, weighting agents, etc.), sewage, sewage oil and Rock powder and other multiphase stable colloidal suspensions have complex components, and most of the pollution indicators such as heavy metal ions, COD, BOD, chroma, suspended solids, petroleum, and PH value are higher than the national comprehensive pollutant discharge standards. However, usually every time a drilling is completed, several or even hundreds of cubic meters of waste flushing fluid are generated. Due to the good stability of the waste flushing fluid, the difficulty of direct dehydration and the special properties of excellent water retention, the waste flushing fluid can be directly dehydrated without treatment. The discharge will cause serious pollution to the surrounding ecological environment.

The current research is mainly aimed at the harmless treatment of drilling waste in the oil and gas field, and there are complex treatment processes, high requirements for treatment equipment, high costs, and the treatment effect is greatly affected by environmental conditions. The stratum encountered and the type of flushing fluid are quite different from oil and gas drilling, and the waste flushing fluid produced is also quite different, which is mainly manifested in the high water content of the pollutants and the small particle size of the solid phase particles of the pollutants (solid phase). The median particle size D50 is 10-100 μm), and the colloid rate is high; the conventional gel breaking-flocculation treatment effect is not obvious, and the gel breaking efficiency is low. After solid-liquid separation, the pollution index in the liquid phase is still high, and the separated The solid phase is less effective for the next curing process.

Therefore, the present invention mainly studies a harmless treatment method for the waste flushing fluid of geological drilling, which can effectively improve the gel breaking efficiency after treatment, and at the same time, the pollution index in the liquid phase is greatly reduced after solid-liquid separation. When the solid phase is solidified after liquid separation, the strength of the solidified body can be significantly improved, the exudation of heavy metal ions and organic substances can be effectively prevented, and the harmless treatment of the waste rinsing liquid can be finally realized.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a kind of harmless treatment technical method of waste flushing liquid, to solve the problem that the waste flushing liquid produced in geological core drilling construction pollutes the environment.

The harmless treatment method of the waste flushing liquid of the present invention comprises the following contents:

The gel breaking reagent is added to the waste rinsing liquid with a moisture content of ≥85%, and the mixture is stirred evenly to obtain a mixture A; the gel breaking reagent includes: aluminum salt and dithiocyanomethane;

The flocculation reagent is added to the mixture A, and the mixture is stirred uniformly to obtain the mixture B; the flocculation reagent includes: polydimethyldiallyl ammonium chloride;

The coagulation aid is added to the mixture B, and the mixture is stirred uniformly to obtain the mixture C; the coagulation aid includes: hydrophilic nano-silica and talc;

The mixture C is subjected to solid-liquid separation to obtain liquid phase D and solid phase E;

The oxidizing reagent is added to the liquid phase D, and the oxidative decolorization treatment is carried out to directly discharge; the oxidizing reagent is selected from one or both of calcium hypochlorite and sodium hypochlorite;

The curing agent is added to the solid phase E, and the curing agent is formed after stirring evenly; the curing agent includes: PO42.5 ordinary Portland cement, polycarboxylate superplasticizer and sodium silicate.

Further, the gel breaking reagent includes: by weight, 8-14 parts of aluminum salt and 0.1-0.3 part of dithiocyanomethane; the aluminum salt is selected from one or more of aluminum sulfate, aluminum chloride, and polyaluminum chloride. The addition amount of the gel breaking reagent is as follows: the addition amount of aluminum salt is 8-14kg and the addition amount of dithiocyanomethane is 0.1-0.3kg per cubic meter of waste flushing solution.

Further, the method of adding the gel breaking reagent is as follows: the aluminum salt is prepared into an aqueous solution with a mass concentration of 5% and then added to the discarded flushing solution, and the dithiocyanomethane is prepared into an aqueous solution with a mass concentration of 1% and added to the discarded rinsing solution. in the rinse solution.

Among them, aluminum salt and dithiocyanomethane can be respectively prepared into aqueous solutions of different mass concentrations, and then added to the waste flushing solution. The solid aluminum salt and the solid dithiocyanomethane can also be mixed according to the ratio of 8 to 14 parts of aluminum salt and 0.1 to 0.3 part of dithiocyanomethane, and then prepared into an aqueous solution and added to the waste rinse solution.

In practical application, it is preferable to prepare aluminum salt and dithiocyanomethane into aqueous solutions of different mass concentrations (5% and 1%, respectively), and then carry out the process according to the actual situation (for example, the volume of the waste flushing liquid to be treated). Add to.

Moreover, the applicant found through research that it is necessary to pre-formulate aluminum salts and dithiocyanomethane into aqueous solutions of a certain mass concentration (5% and 1%, respectively), and then add them to the waste flushing liquid, which has better breaking capacity. glue effect. If the aluminum salt and dithiocyanomethane are directly added to the waste flushing solution in solid form or in the form of a higher concentration aqueous solution, the gel breaking effect is poor.

Further, the add-on of flocculation reagent is: the add-on of polydimethyldiallyl ammonium chloride in every cubic meter of waste flushing liquid is 0.5-1kg. In order to facilitate the on-site operation, the preferred method of adding the flocculation reagent is as follows: polydimethyldiallyl ammonium chloride is prepared into an aqueous solution with a mass concentration of 2% and then added to mixture A.

Further, the coagulation aids include: by weight, 1-2 parts of hydrophilic nano-silicon dioxide and 1 part of talc; the added amount of the coagulation aids per cubic meter of waste flushing liquid is 1-3kg. The method of adding the coagulation aid agent is as follows: the coagulation aid agent is prepared into an aqueous suspension with a mass concentration of 2% and then added to the mixture B.

Further, the oxidizing reagent is calcium hypochlorite; its addition amount is: 5-10 kg of calcium hypochlorite is added to each cubic liquid phase D.

Further, the curing agent includes: by weight, 25-40 parts of PO42.5 ordinary Portland cement, 0.1-0.2 parts of polycarboxylate superplasticizer and 3-5 parts of sodium silicate. The addition amount of the curing agent is: per 100g of solid phase D, add PO42.5 ordinary Portland cement 25-40g, polycarboxylate superplasticizer 0.1-0.2mL, and sodium silicate with a modulus of 2.2-2.5 3- 5g.

Compared with the prior art, the beneficial effects of the present invention are as follows:

The harmless treatment method for waste flushing liquid provided by the present invention adopts special coagulation aid reagent, which cooperates with gel breaking reagent, flocculation reagent, oxidizing reagent and curing reagent, and has high gel breaking efficiency, and the liquid phase after solid-liquid separation Pollution indicators (such as COD, chromaticity, suspended solids, etc.) are greatly reduced, the solid strength after solidification and molding is high, and the dissolution of harmful substances in waste rinse fluid and treatment reagents is avoided, and environmental pollution is reduced. The harmless treatment method of the invention is especially suitable for the waste flushing fluid of geological drilling with high water content of pollutants, small particle size of solid phase particles of pollutants (the median particle size of solid phase D50 is 10-100 μm) and high colloid rate processing.

Detailed ways

The present invention will be further described in detail below in conjunction with test examples and specific embodiments. But it should not be construed that the scope of the above-mentioned subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention all belong to the scope of the present invention.

Example 1

The harmless treatment method for the waste flushing fluid of geological drilling, including the following:

(1) Pretreatment: Use dilution method or conventional solid control equipment (such as vibrating screen or centrifuge, etc.) to pretreat the waste washing liquid, so that the water content of the waste washing liquid is ≥85%; among them, take 5 parts of 1 cubic meter The waste rinsing solution was subjected to subsequent harmless treatment tests respectively.

(2) Add gel breaking reagent: add gel breaking reagent to the waste rinse solution after pretreatment (wherein, 10kg of aluminum sulfate and 0.2kg of dithiocyanomethane are added to the waste rinse solution per cubic meter), and stir after adding. Breaking the gel to realize the breaking and destabilizing of the waste washing liquid; (wherein, aluminum sulfate is added in the form of an aqueous solution with a mass concentration of 5%; dithiocyanomethane is added in the form of an aqueous solution with a concentration of 1%)

(3) Add flocculation reagent: add flocculation reagent polydimethyldiallyl ammonium chloride (Aladdin, item number: P109721) to the waste rinse solution after gel breaking treatment, and add polydimethacrylate to every cubic meter of waste rinse solution. Methyldiallylammonium chloride 0.8kg. Specifically, the method for adding polydimethyldiallyl ammonium chloride is to dilute it into a solution with a mass concentration of 2%, add it slowly while stirring, and the stirring speed is 50-100 rpm;

(4) Add coagulation aid: mix hydrophilic nano-silica (particle size: 7-40nm) (Aladdin, item number: S104587) and talc (800 mesh) (Aladdin, item number: T109494) according to different weights The coagulation aids of different formulations were prepared (see Table 1 for details), and then the coagulation aids of different formulations were added to water to prepare a suspension with a mass concentration of 2%. In the waste rinse liquid of the agent, stir evenly; wherein, 2kg of coagulation aid reagent is added to each cubic meter of waste rinse liquid;

Table 1 Formulation of coagulation aid reagent

(5) Carry out solid-liquid separation on the waste washing liquid after gel breaking and flocculation treatment, and the separation method can be press filtration or centrifugal separation. For example, in the present embodiment, the pressure filtration separation method is used for separation, and the filtration pressure is 0.6 MPa;

(6) oxidizing reagent is added in the liquid phase after solid-liquid separation, this oxidizing reagent can select calcium hypochlorite or sodium hypochlorite or the mixture of both, adopt calcium hypochlorite in the present embodiment, in every cubic meter of liquid phase Add 8kg of calcium hypochlorite; the liquid phase after oxidation treatment can meet the national sewage discharge standard for direct discharge;

(7) Add a curing agent to the solid phase after the above-mentioned solid-liquid separation for curing and molding: add 25g PO42.5 ordinary Portland cement, 0.1ml polycarboxylate superplasticizer and 3g silicon to the 100g solid phase after separation Sodium (modulus is 2.2～2.5), of which sodium silicate and polycarboxylate superplasticizer are produced by Chengdu Yuekuai Trading Co., Ltd.

5 parts of the liquid phase treated in (6) and 5 parts of the solid phase cured and formed in (7) were respectively detected, and the obtained index results are shown in Table 2.

The detection result of table 2 embodiment 1

Among them, in Table 2,

Water yield: refers to the waste rinsing liquid after gel breaking and flocculation treatment in step (5), which is subjected to solid-liquid separation by gas pressure filtration (air pressure 0.6 MPa), and the volume of water pressure filtered and the volume of the rinsing liquid before pressure filtration Compare;

COD (mg/L): refers to the COD index value after testing the liquid phase treated in (6) according to the national environmental protection standard (HJ 828-2017 Determination of water chemical oxygen demand by dichromate method);

Chromaticity (dilution ratio): refers to the chromaticity index value after testing the liquid phase treated in (6) in accordance with the national standard (the measurement standard of water chromaticity GB 11903-1989);

Suspended solids (mg/L): refers to the suspended solids index value after testing the liquid phase treated in (6) according to the national standard (Grometric method for determination of suspended solids in water quality GB 11901-1989);

Compressive strength MPa of cured body 3d: refers to the compressive strength index value of the solid phase cured and formed in (7) after three days of conventional curing.

It can be seen from Table 2: when the ratio of hydrophilic nano-silica to talc is 2:1, the amount of water that can be separated is the highest, the COD and chromaticity indexes are the lowest, the 3d compressive strength of the solidified body is the highest, and the suspended solids index is the highest. There is no significant difference with other formulations.

Example 2

The harmless treatment method for the waste flushing fluid of geological drilling, including the following:

(1) Pretreatment: Use dilution method or conventional solid control equipment (such as vibrating screen or centrifuge, etc.) to pretreat the waste washing liquid, so that the water content of the waste washing liquid is ≥85%; among them, take 5 parts of 1 cubic meter The waste rinsing liquid is subjected to the subsequent harmless treatment test.

(2) Add gel breaking reagent: add gel breaking reagent to the waste rinse solution after pretreatment (wherein, 10kg of aluminum sulfate and 0.2kg of dithiocyanomethane are added to the waste rinse solution per cubic meter), and stir after adding. Breaking the gel to realize the breaking and destabilizing of the waste washing liquid; (wherein, aluminum sulfate is added in the form of an aqueous solution with a mass concentration of 5%; dithiocyanomethane is added in the form of an aqueous solution with a concentration of 1%)

(3) Add flocculation reagent: add flocculation reagent polydimethyldiallyl ammonium chloride (Aladdin, item number: P109721) to the waste rinse solution after gel breaking treatment, and add polydimethacrylate to every cubic meter of waste rinse solution. Methyldiallylammonium chloride 0.8kg. Specifically, the method for adding polydimethyldiallyl ammonium chloride is to dilute it into a solution with a mass concentration of 2%, add it slowly while stirring, and the stirring speed is 50-100 rpm;

(4) Add coagulation aid: mix hydrophilic nano-silica (particle size: 7-40nm) (Aladdin, item number: S104587) and talc (800 mesh) (Aladdin, item number: T109494) according to 2: The coagulation aid was prepared in a weight ratio of 1, and then added to 5 parts of the waste rinsing liquid that had been added with the flocculant according to different addition amounts (see Table 3 for the specific addition), and stirred evenly; the mass concentration of the coagulation aid was 2% was added as a suspension.

Table 3 Addition of coagulation aid reagent

(5) Carry out solid-liquid separation on the waste washing liquid after gel breaking and flocculation treatment, and the separation method can be press filtration or centrifugal separation. For example, in the present embodiment, the pressure filtration separation method is used for separation, and the filtration pressure is 0.6 MPa;

(6) adding the oxidizing reagent to the liquid phase after the solid-liquid separation, that is, adding 8kg of calcium hypochlorite in every cubic meter of the liquid phase; the liquid phase after the oxidation treatment can reach the national sewage discharge standard for direct discharge;

(7) Add a curing agent to the solid phase after the above-mentioned solid-liquid separation for curing and molding: add 25g PO42.5 ordinary Portland cement, 0.1ml polycarboxylate superplasticizer and 3g silicon to the 100g solid phase after separation Sodium (modulus is 2.2～2.5), of which sodium silicate and polycarboxylate superplasticizer are produced by Chengdu Yuekuai Trading Co., Ltd.

5 parts of the liquid phase treated in (6) and 5 parts of the solid phase cured and formed in (7) were respectively detected, and the index results obtained are shown in Table 4.

The detection result of table 4 embodiment 2

The meaning of each index in Table 4 is the same as that in Table 2.

It can be seen from Table 4: with the increasing amount of coagulation aid, the water yield and solid phase compressive strength show a trend of first increasing and then decreasing, while the chromaticity decreases with the increasing amount of coagulation aid; suspended solids Then, because the addition of coagulation aids shows a trend of increasing gradually, in general, the optimal amount of coagulation aids added is between 0.1% and 0.3% (mass concentration), that is, coagulation aids in every cubic meter of waste flushing solution. The amount of reagent added is 1-3kg.

Comparative ratio

The harmless treatment method for the waste flushing fluid of geological drilling, including the following:

(1) Pretreatment: Use dilution method or conventional solid control equipment (such as vibrating screen or centrifuge, etc.) to pretreat the waste washing liquid, so that the water content of the waste washing liquid is ≥85%; The waste rinsing liquid is subjected to the subsequent harmless treatment test.

(2) Add gel breaking reagent: add gel breaking reagent to the waste rinse solution after pretreatment (wherein, 10kg of aluminum sulfate and 0.2kg of dithiocyanomethane are added to the waste rinse solution per cubic meter), and stir after adding. Breaking the gel to realize the breaking and destabilizing of the waste washing liquid; (wherein, aluminum sulfate is added in the form of an aqueous solution with a mass concentration of 5%; dithiocyanomethane is added in the form of an aqueous solution with a concentration of 1%)

(3) Add flocculation reagent: add flocculation reagent polydimethyldiallyl ammonium chloride (Aladdin, item number: P109721) to the waste rinse solution after gel breaking treatment, and add polydimethacrylate to every cubic meter of waste rinse solution. Methyldiallylammonium chloride 0.8kg. Specifically, the method for adding polydimethyldiallyl ammonium chloride is to dilute it into a solution with a mass concentration of 2%, add it slowly while stirring, and the stirring speed is 50-100 rpm;

(4) Solid-liquid separation is carried out on the waste washing liquid after gel breaking and flocculation treatment, and the separation method can be press filtration or centrifugal separation. For example, in the present embodiment, the pressure filtration separation method is used for separation, and the filtration pressure is 0.6 MPa;

(5) adding the oxidizing reagent to the liquid phase after the solid-liquid separation, that is, adding 8kg of calcium hypochlorite to the liquid phase per cubic meter; the liquid phase after the oxidation treatment can reach the national sewage discharge standard and be directly discharged;

(6) Add a curing agent to the solid phase after the above-mentioned solid-liquid separation for solidification: add 25g PO42.5 ordinary Portland cement, 0.1ml polycarboxylate superplasticizer and 3g silicon to the 100g solid phase after separation Sodium (modulus is 2.2～2.5), of which sodium silicate and polycarboxylate superplasticizer are produced by Chengdu Yuekuai Trading Co., Ltd.

The liquid phase treated in (5) and the solid phase cured and formed in (6) were tested respectively, and the obtained index results are shown in Table 5.

The test results of the comparative example in Table 5

The meaning of each index in Table 4 is the same as that in Table 2.

It can be seen from Table 5 that since no coagulation aid is added in this comparative example, the water yield is low, and the COD, chromaticity and other pollution indicators in the liquid phase are poor, and the solidification strength in the solid phase needs to be further improved.

Claims (9)

1. A method for the harmless treatment of waste washing liquid comprises the following steps:

adding the gel breaking reagent into the waste flushing fluid with the water content of more than or equal to 85%, and uniformly stirring to obtain a mixture A; the gel breaking reagent comprises: aluminum salts and dithiocyanomethane;

adding a flocculating agent into the mixture A, and uniformly stirring to obtain a mixture B; the flocculating agent comprises: polydimethyldiallyl ammonium chloride;

adding the coagulation aid reagent into the mixture B, and uniformly stirring to obtain a mixture C; the coagulation aid reagent comprises: hydrophilic nano silicon dioxide and talcum powder;

carrying out solid-liquid separation on the mixture C to obtain a liquid phase D and a solid phase E;

adding an oxidizing reagent into the liquid phase D, and directly discharging after oxidation and decoloration treatment; the oxidizing agent is selected from one or two of calcium hypochlorite and sodium hypochlorite;

adding a curing reagent into the solid phase E, uniformly stirring, and curing and forming; the curing agent comprises: p042.5 ordinary Portland cement, a polycarboxylic acid high-efficiency water reducing agent and sodium silicate.

2. The method for detoxifying a waste rinse according to claim 1, wherein said gel breaking reagent comprises: 8-14 parts of aluminum salt and 0.1-0.3 part of dithiocyano-methane by weight; the aluminum salt is selected from one or more of aluminum sulfate, aluminum chloride and polyaluminum chloride; the addition amount of the gel breaking reagent is as follows: 8-14kg of aluminum salt and 0.1-0.3 kg of dithiocyano-methane are added into each cubic meter of waste flushing fluid.

3. The method for detoxifying a waste rinse solution according to claim 2, wherein the gel breaking agent is added in a manner that: preparing an aqueous solution with the mass concentration of 5% from aluminum salt, adding the aqueous solution into the waste flushing fluid, preparing an aqueous solution with the mass concentration of 1% from dithiocyano-methane, and adding the aqueous solution into the waste flushing fluid.

4. A method for detoxifying a waste rinse solution according to claim 1, wherein the amount of the flocculating agent added is: 0.5-1kg of poly dimethyl diallyl ammonium chloride is added into each cubic meter of waste flushing fluid.

5. A method of harmless treatment of a waste flushing liquid according to claim 4, wherein the flocculating agent is added in a manner that: the poly dimethyl diallyl ammonium chloride is prepared into an aqueous solution with the mass concentration of 2 percent and then added into the mixture A

In (1).

6. The method for detoxifying a waste rinse according to claim 1, wherein said coagulation aid comprises: 1-2 parts of hydrophilic nano silicon dioxide and 1 part of talcum powder by weight; the addition amount of the coagulation aid reagent is as follows: 1-3kg of coagulation aid reagent is added into each cubic of waste flushing liquid.

7. The method for detoxifying a waste rinse solution according to claim 6, wherein the coagulation aid is added in a manner that: and (3) preparing the coagulation aid reagent into an aqueous suspension with the mass concentration of 2%, and adding the aqueous suspension into the mixture B.

8. The method for detoxifying a waste rinse solution according to claim 1, wherein said oxidizing agent is calcium hypochlorite; the addition amount of the oxidizing reagent is as follows: 5-10kg of calcium hypochlorite is added into each cubic liquid phase D.

9. The method for detoxifying waste rinse solution according to claim 1, wherein said solidifying agent comprises: 25-40 parts of PO42.5 ordinary portland cement, 0.1-0.2 part of polycarboxylic acid high-efficiency water reducing agent and 3-5 parts of sodium silicate by weight; the addition amount of the curing agent is as follows: every 100g of the solid phase D is added with 25-40g of PO42.5 ordinary portland cement, 0.1-0.2mL of polycarboxylic acid high-efficiency water reducing agent and 3-5g of sodium silicate with the modulus of 2.2-2.5.