Low-temperature drilling waste treatment agent, preparation method and treatment method

Abstract

The invention belongs to the technical field of oil and gas field drilling environment protection, and particularly relates to a low-temperature drilling waste treatment agent, a preparation method and a treatment method. The treating agent is prepared from the following components in percentage by weight: 30 to 40 percent of a flocculating agent, 0.2 to 0.5 percent of a coagulant, 10 to 20 percent of calcined gypsum and 39.7 to 55 percent of diatomite. The method can be used for rapidly and harmlessly treating the drilling wastes in the high and cold environment.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field drilling environment protection, and in particular relates to a low-temperature drilling waste treatment agent, a preparation method and a treatment method. Background Art

[0002] The Qiangtang Basin is located in the hinterland of the Qinghai-Tibet Plateau, in a national nature reserve, covered with permafrost, and has high requirements for vegetation protection. The Qiangtang Basin has a high altitude (average 5,000m), low temperature (below -20℃ in winter), and an average altitude of more than 5,000m. The ecological environment system is fragile and has high requirements for environmental protection. The Qiangtang Basin is rich in oil and gas, rich in oil shale, oil sands, natural gas hydrates and other oil and gas resources. The new round of national capital assessment calculates the conventional oil and gas resources to be 5.1 billion tons. Due to limited natural conditions, exploration and development are extremely difficult. The strata in the Qiangtang Basin are complex and changeable. There are limestone layers, gypsum layers, large sections of mudstone layers, conglomerate layers, sandstone layers, coal seams and other lithologies developed in the shallow strata below 5,000m. In the absence of basic data and preliminary foundations, there are high requirements for the selection of drilling fluid systems and formulations. The mud performance not only needs to have good rheological properties, plugging properties, wall-building properties, and inhibition properties, but also needs to consider multiple factors such as frost resistance and pollution resistance to meet the requirements of complex drilling operations. However, this also makes the drilling waste composition more complex and more difficult to handle.

[0003] Existing drilling waste treatment agents are all for use in plain areas, low-altitude areas, etc., and are not suitable for high-altitude and cold environments.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a low-temperature drilling waste treatment agent, a preparation method and a treatment method. The present invention has the advantages of rapid and harmless treatment of drilling waste in a high-cold environment.

[0006] The present invention includes the following technical solutions:

[0007] The first aspect of the present invention provides a low-temperature drilling waste treatment agent, the treatment agent comprising: the treatment agent comprises the following components:

[0008] Flocculant 30wt%~40wt%

[0009] Coagulant 0.2wt%~0.5wt%

[0010] Plaster of Paris 10wt%~20wt%

[0011] Diatomaceous earth 39.7wt%~55wt%.

[0012] Furthermore, the flocculant includes one or more of polyaluminium chloride, polyferric sulfate and sulfuric acid.

[0013] Furthermore, the coagulant is one or two of potassium sulfate, calcium formate and magnesium oxychloride.

[0014] The second aspect of the present invention provides a method for preparing a low-temperature drilling waste treatment agent, comprising the following steps:

[0015] The flocculant, coagulant, plaster of Paris and diatomaceous earth are fully stirred and mixed;

[0016] crushing the mixed flocculant, coagulant, plaster of Paris and diatomaceous earth to obtain the treating agent;

[0017] Among them: flocculants, coagulants, plaster of Paris and diatomaceous earth are calculated by mass fraction:

[0018] The flocculant is 30 wt% to 40 wt%, the coagulant is 0.2 wt% to 0.5 wt%,

[0019] The plaster of Paris is 10 wt% to 20 wt%, and the diatomaceous earth is 39.7 wt% to 55 wt%.

[0020] Further, the mixed flocculant, coagulant, plaster of Paris and diatomaceous earth are pulverized in a dry environment.

[0021] Furthermore, the mixed flocculant, coagulant, plaster of Paris and diatomaceous earth are crushed to 80-100 meshes to obtain the treating agent.

[0022] A third aspect of the present invention provides a method for treating low-temperature drilling waste, using the above-mentioned treating agent to treat the drilling waste.

[0023] Further, the following steps are included:

[0024] S100: taking water-based drill cuttings, adding water-soluble monomers, stirring, and standing to obtain a mixture A;

[0025] S200: adding silicate cement to mixture A and mixing thoroughly to obtain mixture B;

[0026] S300: adding the treatment agent to the mixture B and mixing thoroughly to obtain a mixture C;

[0027] S400: adding water to the mixture C and stirring to obtain a mixture D;

[0028] S500: Let stand to obtain a solidified product and an extract.

[0029] Furthermore, in step S500: the obtained mixture D is poured into a mold, compacted, and allowed to stand to obtain a solidified product and an extract.

[0030] Furthermore, the standing time is 1-2 days; the solidified product after standing is cured and demoulded.

[0031] Furthermore, the curing time is 5-7 days.

[0032] Furthermore, in step S100: the stirring time is 10-60 min, and the standing time is 2-4 h.

[0033] Further, in step S400: the stirring time is 1-3h.

[0034] Further, water-based drill cuttings are taken, a water-soluble monomer is added, stirred for 10-60 minutes, and allowed to stand for 2-4 hours to obtain a mixture A;

[0035] Adding silicate cement to mixture A and mixing thoroughly to obtain mixture B;

[0036] Adding the treating agent to mixture B and mixing thoroughly to obtain mixture C;

[0037] Add water to mixture C and stir for 1-3 hours to obtain mixture D;

[0038] The mixture was allowed to stand to obtain a solidified product and an extract.

[0039] Furthermore, the silicate cement is 25wt% to 45wt% of the water-based drill cuttings.

[0040] Furthermore, the solid-liquid mass percentage of the mixture D is 2:1.

[0041] By adopting the above technical solution, the present invention has the following advantages:

[0042] 1. The pH, COD, chromaticity and petroleum indexes of the leaching solution after treatment by the present invention meet the first-level requirements of GB8978.

[0043] 2. The present invention can realize rapid bonding and demoulding in a low temperature environment of 0 to 20°C.

[0044] 3. The present invention realizes the harmlessness of drilling waste in high-altitude and cold areas. DETAILED DESCRIPTION

[0045] The following description provides many different embodiments or examples for implementing different features of the present invention. The components and arrangements described in the following specific examples are only used to simplify the present invention and are only used as examples, not to limit the present invention.

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] This embodiment provides a low-temperature drilling waste treatment agent, the treatment agent comprising: the treatment agent comprises the following components:

[0048] Flocculant 30wt%~40wt%

[0049] Coagulant 0.2wt%~0.5wt%

[0050] Plaster of Paris 10wt%~20wt%

[0051] Diatomaceous earth 39.7wt%~55wt%.

[0052] Drilling waste includes drilling fluid and drill cuttings, namely the water-containing drill cuttings mentioned in the present invention; the inventive concept of the present invention mainly lies in decomposing and solidifying the pollutants in the drilling waste (i.e. forming a cemented body); due to the particularity of the environment in high-altitude cold areas, it is necessary to consider the effect of temperature on the treatment agent when treating the drilling waste, that is, the formation speed of the cemented body is slow in a low temperature environment, resulting in a long treatment time and poor treatment effect, and the treatment agent of the present invention can increase the speed of cemented body formation, reduce the treatment time and improve the treatment effect.

[0053] The curing agent is mainly used to solidify pollutants, and fixes organic matter and other pollutants in the residue by cementing and solidifying the residue. At the same time, it is stably adsorbed on the surface of the hydrophilic residue through the carboxyl group, and has a stable energy minimum point, thereby maintaining a long-term stable solidification effect on pollutants; decomposition is reflected in the destruction of the electrical stability between the colloid particles.

[0054] In some embodiments, the flocculant includes one or more of polyaluminium chloride, polyferric sulfate and aluminium sulfate.

[0055] In some embodiments, the coagulant is one or two of potassium sulfate, calcium formate and magnesium oxychloride. Based on this, the coagulant is more suitable for use in a low temperature environment.

[0056] This embodiment also provides a method for preparing a low-temperature drilling waste treatment agent, comprising the following steps:

[0057] The flocculant, coagulant, plaster of Paris and diatomaceous earth are fully stirred and mixed;

[0058] crushing the mixed flocculant, coagulant, plaster of Paris and diatomaceous earth to obtain the treating agent;

[0059] Among them: flocculants, coagulants, plaster of Paris and diatomaceous earth are calculated by mass fraction:

[0060] The flocculant is 30 wt% to 40 wt%, the coagulant is 0.2 wt% to 0.5 wt%,

[0061] The plaster of Paris is 10 wt% to 20 wt%, and the diatomaceous earth is 39.7 wt% to 55 wt%.

[0062] In some embodiments, the mixed flocculant, coagulant, plaster of Paris and diatomaceous earth are pulverized in a dry environment.

[0063] In some embodiments, the mixed flocculant, coagulant, plaster of Paris and diatomaceous earth are crushed to 80-100 meshes to obtain the treating agent.

[0064] This embodiment also provides a method for treating low-temperature drilling waste, using the treatment agent as described in any one of claims 1-5 to treat the drilling waste.

[0065] In some embodiments, the steps include:

[0066] Take water-based drill cuttings, add water-soluble monomer, stir, and let stand to obtain mixture A;

[0067] Adding silicate cement to mixture A and mixing thoroughly to obtain mixture B;

[0068] Adding the treating agent to mixture B and mixing thoroughly to obtain mixture C;

[0069] Add water to mixture C and stir to obtain mixture D;

[0070] The mixture is allowed to stand to obtain a solidified product and an extract, wherein the pH, COD, chromaticity and petroleum indexes of the extract meet the first-level requirements of GB8978.

[0071] This method enables the pollutants to decompose and solidify (ie form a cemented mass).

[0072] In some embodiments, the obtained mixture D is poured into a mold, compacted, and allowed to stand to obtain a solidified product and an extract. The solidified product is shaped by the mold to support unburned bricks and can be used in other places, achieving harmless treatment and having economic benefits.

[0073] In some embodiments, the standing time is 1-2 days; the solidified product after standing is cured and demolded; preferably, the curing time is 5-7 days.

[0074] In some embodiments, water-based drill cuttings are taken, a water-soluble monomer is added, stirred for 10-60 min, and allowed to stand for 2-4 h to obtain a mixture A; wherein the water-soluble monomer is a drilling waste fluid decolorizer;

[0075] Adding silicate cement to mixture A and mixing thoroughly to obtain mixture B;

[0076] Adding the treating agent to mixture B and mixing thoroughly to obtain mixture C;

[0077] Add water to mixture C and stir for 1-3 hours to obtain mixture D;

[0078] The mixture is allowed to stand to obtain a solidified product and an extract, wherein the pH, COD, chromaticity and petroleum indexes of the extract meet the first-level requirements of GB8978.

[0079] By limiting the stirring time and the standing time, better treatment effects can be achieved and the speed of forming a cemented body in a low temperature environment can be increased.

[0080] In some embodiments, the silicate cement is 25wt% to 45wt% of the water-based drill cuttings, thereby achieving a better treatment effect.

[0081] In some embodiments, the solid-liquid mass percentage of the mixture D is 2:1. Based on this, it has the advantages of reducing the solidification time and improving the treatment effect.

[0082] The solidified body is the solidified material, and the pH, COD, chromaticity and petroleum indexes of the leachate of the solidified material meet the requirements of GB8978 standard, which means that the drilling waste has been treated.

[0083] The low-temperature drilling waste treatment method of the present invention shortens the treatment time to one day, which is shorter than the prior art.

[0084] Based on the above processing method, the following are specific examples:

[0085] Example 1:

[0086] Put polyaluminium chloride, potassium sulfate, plaster of Paris and diatomaceous earth into a dry and clean beaker in the mass ratio of 35%, 0.3%, 20% and 44.7% in turn, stir and mix thoroughly, and grind to 80 mesh in a dry environment to obtain a treatment agent;

[0087] 70 g of water-based drill cuttings from the Xiantang area were taken, water-soluble monomer A was added, stirred for 30 min, and allowed to stand for 2 hours to obtain mixture A;

[0088] Add 30 g of Portland cement to mixture A and mix thoroughly to obtain mixture B;

[0089] Add 10 g of the treatment agent to mixture B and mix thoroughly to obtain mixture C;

[0090] Water was added to mixture C to make the solid-liquid mass ratio 2:1, and stirring was continued for 2 hours to obtain mixture D;

[0091] Pour the mixture D into a mold, compact it, let it stand, and react for 2 days to obtain a solidified product and an extract;

[0092] The cured product is cured for 7 days and then demoulded.

[0093] As shown in Table 1, the leachate was tested for relevant indicators according to the requirements of GB8978-96 "National Integrated Wastewater Discharge Standard".

[0094] Example 2:

[0095] Put polyferric sulfate, calcium formate, magnesium oxychloride, plaster of Paris and diatomaceous earth in a dry and clean beaker in a mass ratio of 40%, 0.1%, 0.2%, 20% and 39.7% in turn, stir and mix thoroughly, and grind to 100 mesh in a dry environment to obtain a treatment agent;

[0096] 65 g of water-based drill cuttings from the Xiantang area were taken, water-soluble monomer A was added, stirred for 10 min, and allowed to stand for 3 hours to obtain mixture A;

[0097] Add 30 g of Portland cement to mixture A and mix thoroughly to obtain mixture B;

[0098] Add 5 g of the treatment agent to mixture B and mix thoroughly to obtain mixture C;

[0099] Add 50 g of water to mixture C to make the solid-liquid mass ratio 2:1, and continue stirring for 1 hour to obtain mixture D;

[0100] Pour the mixture D into a mold, compact it, let it stand, and react for 2 days to obtain a solidified product and an extract;

[0101] The cured product was cured for 5 days and then demoulded.

[0102] As shown in Table 1, the leachate was tested for relevant indicators according to the requirements of GB8978-96 "National Integrated Wastewater Discharge Standard".

[0103] Example 3:

[0104] Aluminum sulfate, calcium formate, plaster of Paris, and diatomaceous earth are placed in a dry and clean beaker in a mass ratio of 30%, 0.5%, 15%, and 54.5% in sequence, stirred and mixed thoroughly, and crushed to 100 mesh in a dry environment to obtain a treatment agent;

[0105] 70 g of drill cuttings from the Xiantang area were taken, water-soluble monomer A was added, stirred for 40 min, and allowed to stand for 4 hours to obtain mixture A;

[0106] Add 30 g of Portland cement to mixture A and mix thoroughly to obtain mixture B;

[0107] Add 10 g of the treatment agent to mixture B and mix thoroughly to obtain mixture C;

[0108] Add water to mixture C to make the solid-liquid mass ratio 2:1, and continue stirring for 3 hours to obtain mixture D;

[0109] Pour the mixture D into a mold, compact it, let it stand, and react for 1 day to obtain a solidified product and an extract;

[0110] The cured product is cured for 7 days and then demoulded.

[0111] As shown in Table 1, the leachate was tested for relevant indicators according to the requirements of GB8978-96 "National Integrated Wastewater Discharge Standard".

[0112] Table 1

[0113]

[0114] It can be seen from Table 1 that the pH, COD, chromaticity and petroleum indicators of the treated leaching solution meet the first-level requirements of GB8978.

[0115] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-temperature drilling waste treatment agent, characterized in that: The treatment agent includes: The treatment agent includes the following components: Flocculant 30wt%~40wt% Coagulant 0.2wt%~0.5wt% Plaster of Paris 10wt%~20wt% Diatomaceous earth 39.7wt%~55wt%.

2. A low-temperature drilling waste treatment agent as claimed in claim 1, characterized in that: The flocculant includes one or more of polyaluminium chloride, polyferric sulfate and sulfuric acid.

3. A low-temperature drilling waste treatment agent as claimed in claim 1, characterized in that: The coagulant is one or two of potassium sulfate, calcium formate and magnesium oxychloride.

4. A method for preparing a low-temperature drilling waste treatment agent, characterized in that: The steps include: The flocculant, coagulant, plaster of Paris and diatomaceous earth are fully stirred and mixed; crushing the mixed flocculant, coagulant, plaster of Paris and diatomaceous earth to obtain the treating agent; Among them: flocculants, coagulants, plaster of Paris and diatomaceous earth are calculated by mass fraction: The flocculant is 30 wt% to 40 wt%, the coagulant is 0.2 wt% to 0.5 wt%, The plaster of Paris is 10 wt% to 20 wt%, and the diatomaceous earth is 39.7 wt% to 55 wt%.

5. The method for preparing a low-temperature drilling waste treatment agent according to claim 4, characterized in that: The mixed flocculant, coagulant, plaster of Paris and diatomaceous earth are crushed and ground in a dry environment.

6. The method for preparing a low-temperature drilling waste treatment agent according to claim 5, characterized in that: The mixed flocculant, coagulant, plaster of Paris and diatomaceous earth are crushed to 80-100 meshes to obtain the treating agent.

7. A method for treating low-temperature drilling waste, characterized in that: Use the treating agent as described in any one of claims 1 to 3 to treat drilling waste.

8. A method for treating low-temperature drilling waste according to claim 7, characterized in that: The steps include: S100: taking water-based drill cuttings, adding water-soluble monomers, stirring, and standing to obtain a mixture A; S200: adding silicate cement to mixture A and mixing thoroughly to obtain mixture B; S300: adding the treatment agent to the mixture B and mixing thoroughly to obtain a mixture C; S400: adding water to the mixture C and stirring to obtain a mixture D; S500: Let stand to obtain a solidified product and an extract.

9. A method for treating low-temperature drilling waste according to claim 8, characterized in that: In step S500: pour the obtained mixture D into a mold, compact it, and let it stand to obtain a solidified product and an extract.

10. A method for treating low-temperature drilling waste according to claim 9, characterized in that: The standing time is 1-2 days; the solidified product after standing is cured and demoulded.

11. A method for treating low-temperature drilling waste according to claim 10, characterized in that: The curing time is 5-7 days.

12. A method for treating low-temperature drilling waste according to claim 8, characterized in that: In step S100: the stirring time is 10-60 minutes, and the standing time is 2-4 hours.

13. A method for treating low-temperature drilling waste according to claim 12, characterized in that: In step S400: the stirring time is 1-3 hours.

14. A method for treating low-temperature drilling waste according to any one of claims 7 to 13, characterized in that: The silicate cement is 25wt% to 45wt% of the water-based drill cuttings.

15. A method for treating low-temperature drilling waste according to any one of claims 7 to 13, wherein the solid-liquid mass percentage of the mixture D is 2:1.

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