Oil-based rock debris counter-current extraction agent and preparation and application thereof

Abstract

The invention discloses a counter-current extraction agent which comprises the following components: extraction target oil, methyl ethyl ketone, sodium silicate and water in a mass ratio of (40-60): (10-20): (0.2-0.5): (20-30). The invention also discloses a preparation method and application thereof. According to the oil-based rock debris resourceful treatment method, oil is extracted through a low-temperature counter-current extraction technology, barite minerals are extracted from deoiled solid phases through a flotation method, a propping agent is prepared from flotation tailings, and development of an efficient extraction agent and a flotation agent is carried out. After counter-current extraction, the oil content of the oil-based rock debris tailings can be reduced to 0.3% or below.

Description

Technical Field

[0001] The invention relates to an oil-based rock cuttings countercurrent extractant and a preparation method and application thereof. Background Art

[0002] Oil-based drilling fluid is widely used in the development of unconventional oil and gas resources such as shale gas and tight gas. It is composed of mineral oil, water, weighting agent, organic clay and a variety of oil-soluble chemical treatment agents. It has the advantages of high temperature resistance, salt and calcium corrosion resistance, good well wall stability, good lubricity and little damage to oil and gas layers. During drilling operations, oil-based drilling fluid carries the cuttings drilled out of the formation back to the ground. After being treated by the well site solid control system, the lower phase drilling fluid is recycled, and the upper phase remains are oil-based cuttings. The main components of oil-based cuttings are mineral oil, organic compounds such as phenols and a variety of inorganic minerals. If the mineral oil and organic compounds contained in them are not properly treated and discharged, they will pollute the soil, surface and groundwater, and directly or indirectly harm plants, animals, human health and the surrounding ecological environment.

[0003] The average oil content of oil-based rock cuttings is about 25-40%, which has a very considerable economic value. The existing technology mainly uses high-temperature and energy-consuming heat treatment to collect the oil in oil-based rock cuttings. The oil content of de-oiled tailings is still higher than 2%, and the barite minerals in the tailings are not effectively utilized, which is still not environmentally friendly as waste disposal. Summary of the invention

[0004] The present invention is made in order to further improve the environmental protection treatment of oil-based cuttings and the comprehensive utilization of resources.

[0005] The extraction target oil referred to in the present invention refers to the target oil determined based on the type of base oil in the oil-based rock cuttings extracted by the countercurrent extractant. For example, the base oil corresponding to diesel-based rock cuttings is diesel, and the base oil corresponding to white oil-based rock cuttings is white oil.

[0006] As one aspect of the present invention, it relates to a countercurrent extractant, which comprises components in the following mass ratio: the mass ratio of extraction target oil (diesel or white oil), methyl ethyl ketone, sodium silicate and water is 40-60:10-20:0.2-0.5:20-30, and the preferred mass ratio is 45-55:15-20:0.2-0.3:20-25.

[0007] As another aspect of the present invention, it relates to a method for preparing the above countercurrent extractant: the extraction target oil (diesel or white oil), methyl ethyl ketone, sodium silicate and water are mixed according to a mass ratio.

[0008] As another aspect of the present invention, it relates to a method for extracting oil from oil-based rock cuttings, comprising: extracting the oil-based rock cuttings using the above-mentioned countercurrent extractant.

[0009] In a specific embodiment, the above method comprises the following steps:

[0010] Add oil-based rock cuttings and the above countercurrent extractant in a liquid-to-solid ratio of 3-5:1, and extract at 15-40°C.

[0011] In a specific embodiment, the extraction is a three-stage countercurrent extraction, the single-stage extraction time is 20-35 minutes, and the stirring speed is 350-500 r / min.

[0012] In a specific embodiment, the method performs liquid-solid separation after the extraction step to obtain a solid phase and a liquid phase, and the liquid phase is subjected to oil-water separation.

[0013] In a specific embodiment, after oil-water separation in the method, the obtained water phase is recycled to the countercurrent extraction step, and 80-90% of the obtained oil phase enters the countercurrent extraction step.

[0014] As another aspect of the present invention, it relates to a comprehensive utilization process of oil-based rock cuttings, including the above-mentioned method for extracting oil from the oil-based rock cuttings.

[0015] In a specific embodiment, the solid phase obtained by centrifugation of the oil-containing oil-based cuttings is extracted using a barite extraction method, and the residual flotation tailings. The barite extraction method uses a flotation system comprising a targeted barite collector, an inhibitor, a dispersant and a frother for flotation; the inhibitor is a compound of sodium phosphate, water glass, and tannic acid in a mass ratio of 1:1-2:1-3, and the dosage is 800-1200g / t; the frother is pine oil, and the dosage is 5-15g / t; the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1-2:1-3:1, and the dosage is 0.25-1%; the targeted barite collector comprises a bipyridylium salt and a carboxylic acid, and the bipyridylium salt is:

[0016]

[0017]

[0018] The carboxylic acid is a mixture of any one or more of oxalic acid, p-hydroxybenzoic acid, trimesic acid, nicotinic acid, and 6-chloronicotinic acid, and the molar ratio of the bipyridylium salt to the carboxylic acid is 1:2-2:1.

[0019] In a specific embodiment, the comprehensive utilization process of oil-based rock cuttings is to extract the solid phase obtained by centrifugation from the above oil-based rock cuttings using the above barite extraction method, and the remaining flotation tailings.

[0020] In a specific embodiment, the comprehensive utilization process of the oil-based rock cuttings further includes: preparing a proppant using the flotation tailings.

[0021] In a specific embodiment, the preparation of proppant using the flotation tailings refers to: drying the flotation tailings at 105°C for 3-4h, mixing the tailings, bauxite and potassium feldspar in a mass ratio of 2-3:5-7:1-2 after drying, ball milling and sieving to obtain a mixture below 45μm, adding polyvinyl alcohol solution to the mixture in a mass ratio of polyvinyl alcohol solution (3-5wt%) to the mixture of 1:7-10, mixing and granulating, naturally drying and sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, and sending it into a resistance furnace for sintering, the sintering temperature is 1150-1300°C, the heating rate is 5-10°C / min, and the temperature is kept for 2-3h after reaching the temperature. After stopping the furnace for cooling, the corresponding mesh number (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant products are obtained.

[0022] The present invention provides a method for processing oil-based rock cuttings resources, which is centered on extracting oil by low-temperature countercurrent extraction, extracting barite minerals from deoiled solid phase by flotation, and preparing proppant by flotation tailings, and develops high-efficiency extractants and flotation agents. After countercurrent extraction, the oil content of oil-based rock cuttings tailings can be reduced to less than 0.3%; further extraction by flotation, the recovery rate of barite can reach more than 95%, and the proppant fired by flotation tailings meets the requirements of 35MPa specification products in SY / T5108-2014, realizing full resource utilization of oil-based rock cuttings.

[0023] The process of the present invention is proposed for the characteristics of oil-based cuttings rich in useful components such as white oil or diesel (collectively referred to as base oil), barite minerals, etc., and adopts the technical route of "countercurrent extraction to remove base oil - flotation extraction of barite - tailings burning proppant" to achieve deep resource disposal of oil-based cuttings. The recovered base oil can be used to mix drilling fluid, the extracted barite can be used as a weighting agent to be reused in drilling fluid, and the remaining flotation tailings can be used as a raw material for preparing fracturing proppants, achieving the dual goals of harmlessness and resource utilization, solving the environmental protection problems that plague oil and gas field development companies, and escorting the clean and harmless production of shale gas. At present, the field of oil-based cuttings processing focuses on oil and light solids, and high-temperature and energy-consuming thermal treatment is mostly used to recover oil. In addition, the oil content of de-oiled tailings is higher than 2%, and 40-60% of barite minerals in the tailings have not been effectively utilized. In response to this situation, a resource processing method of low-temperature countercurrent extraction of oil and flotation extraction of barite has been developed, and the tailings after flotation are used to prepare fracturing proppants. At the same time, high-efficiency countercurrent extraction agents for base oils and targeted barite collectors have been developed, which better achieve the purpose of extracting oil and minerals from oil-based cuttings and using tailings to prepare proppants, and more thoroughly realize the resource utilization of oil-based cuttings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of the method for resource processing of oil-based rock cuttings provided by the present invention.

[0025] Figure 2 It is an operation schematic diagram of the countercurrent extraction unit in the oil-based rock cuttings resource processing flow chart provided by the present invention. DETAILED DESCRIPTION

[0026] The following is a detailed description of the embodiments of the present invention: The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are given, but the protection scope of the present invention is not limited to the following embodiments. The process parameters for which specific conditions are not specified in the following embodiments are generally based on conventional conditions.

[0027] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0028] The corresponding operation steps of the following embodiments can be referred to in the attached Figure 1 and attached Figure 2 to achieve.

[0029] The bipyridylium salt structural formula used in the embodiments of the present invention is as follows:

[0030]

[0031]

[0032] Example 1

[0033] The diesel-based rock cuttings were crushed to less than 75 μm and transported to a three-stage countercurrent extraction system, and a countercurrent extractant was added at a liquid-solid ratio of 3:1. The countercurrent extractant was prepared by mixing diesel, methyl ethyl ketone, sodium silicate and water at a mass ratio of 45:15:0.3:25. The extraction temperature was 25°C, the single-stage extraction time was 25 minutes, and the stirring speed was 450 r / min. After extraction, solid-liquid separation was performed by centrifugation at a centrifugal speed of 3000 r·min -1 The liquid phase is further separated into oil and water, and the obtained water phase is reused in the countercurrent extraction stage. 90% of the obtained oil phase enters the countercurrent extraction stage, and 10% is used to mix drilling fluid. The solid phase obtained by centrifugation has an oil content of 0.25%, which enters the flotation stage for the extraction of barite.

[0034] The solid phase obtained by centrifugation was ground to less than 50 μm, and added to a mixture containing an inhibitor (sodium phosphate, water glass and tannic acid were mixed in a mass ratio of 1:1:2, with an amount of 900 g / t) and a targeted barite collector (a 5 wt% solution 1 was obtained by dissolving bipyridylium salt (a) in solvent N,N-dimethylformamide, and a 5 wt% solution 2 was obtained by dissolving oxalic acid in solvent ethanol, and the solution was stirred at a molar ratio of bipyridylium salt (a) to oxalic acid of 1:1.5). The flotation system of the ore dressing agent was prepared by mixing 1 with solution 2 to obtain a targeted barite collector, with a dosage of 500 g / t), a dispersant (sodium pyrophosphate, sodium hexametaphosphate and water glass mixed in a mass ratio of 1:2:1, with a dosage of 0.35%), and a frother (pine oil, with a dosage of 10 g / t). The flotation temperature was controlled at 35°C, the flotation time was 60 min, and the pulp concentration was 15%. After flotation, the recovery rate of barite was 96%, and the density was 4.2 g cm -3 , the flotation tailings enter the proppant preparation stage.

[0035] The flotation tailings are dried at 105°C for 3 hours. After drying, the tailings, bauxite and potassium feldspar are mixed in a mass ratio of 2:5:2, ball milled and sieved to obtain a mixture below 45 μm. Polyvinyl alcohol solution is added to the mixture in a mass ratio of 1:7 of polyvinyl alcohol solution (4wt%) to the mixture, mixed and granulated, dried naturally, sieved (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh), and the raw material of the proppant is obtained, which is sent to a resistance furnace for sintering at a sintering temperature of 1280°C and a heating rate of 5°C / min. After reaching the temperature, it is kept for 2.5 hours. After the furnace is stopped and cooled, the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) of the proppant clinker is obtained. Among them, the volume density of the 20 / 40 mesh product is 1.26g·cm -3 , the crushing rate at 35MPa is 9.24%; the volume density of 30 / 50 mesh product is 1.30g·cm -3 , the crushing rate at 35MPa is 7.86%; the volume density of 40 / 70 mesh product is 1.40g·cm -3 , the crushing rate is 6.31% at 35MPa.

[0036] Example 2

[0037] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method refers to Example 1. The difference from Example 1 is that the extractant is obtained by compounding diesel, methyl ethyl ketone, sodium silicate and water in a mass ratio of 40:10:0.2:20, the extraction temperature is 35°C, the single-stage extraction time is 20min, the stirring speed is 400r / min, and the oil content of the tailings after extraction is 0.28%.

[0038] Example 3

[0039] In this embodiment, the treatment object is diesel-based rock chips, and the treatment method refers to Example 2. The difference from Example 2 is that the extraction temperature is 15°C, the single-stage extraction time is 20 minutes, the stirring speed is 350r / min, and the oil content of the tailings after extraction is 0.5%.

[0040] Example 4

[0041] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method refers to Example 2. The difference from Example 2 is that the extractant is obtained by compounding diesel, methyl ethyl ketone, sodium silicate and water in a mass ratio of 60:20:0.5:30, the extraction temperature is 40°C, the single-stage extraction time is 35min, the stirring speed is 500r / min, and the oil content of the tailings after extraction is 0.16%.

[0042] Example 5

[0043] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method refers to Example 2. The difference from Example 2 is that the extractant is obtained by compounding diesel, methyl ethyl ketone, sodium silicate and water in a mass ratio of 60:20:0.5:30, the extraction temperature is 50°C, the single-stage extraction time is 40min, the stirring speed is 550r / min, and the oil content of the tailings after extraction is 0.45%.

[0044] Example 6

[0045] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method refers to Example 2. The difference from Example 2 is that the extractant is obtained by compounding diesel, methyl ethyl ketone, sodium silicate and water in a mass ratio of 60:20:0.5:30, the extraction temperature is 10°C, the single-stage extraction time is 15min, the stirring speed is 300r / min, and the oil content of the tailings after extraction is 0.85%.

[0046] Example 7

[0047] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method is referred to Example 1. The difference from Example 1 is that the inhibitor is a compound of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, and the dosage is 800g / t. The targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (b) in solvent N,N-dimethylformamide, and a solution 2 obtained by dissolving p-hydroxybenzoic acid in solvent ethanol. The solution 1 and the solution 2 are mixed in a molar ratio of bipyridylium salt (b) to p-hydroxybenzoic acid of 2:1, and the dosage is 400g / t. The dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:1:3, and the dosage is 0.25%. The foaming agent is pine oil, and the dosage is 8g / t. The recovery rate of barite after flotation is 95%, and the density is 4.0g·cm -3 .

[0048] Example 8

[0049] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method is referred to Example 1. The difference from Example 1 is that the inhibitor is a compound of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1:1, and the dosage is 1200g / t. The targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (c) in solvent N,N-dimethylformamide, and a solution 2 obtained by dissolving trimesic acid in solvent ethanol. The solution 1 and the solution 2 are mixed in a molar ratio of bipyridylium salt (c) and trimesic acid of 1:2, and the dosage is 600g / t. The dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:1:1, and the dosage is 0.25%. The foaming agent is pine oil, and the dosage is 5g / t. The recovery rate of barite after flotation is 90%, and the density is 4.1g·cm -3 .

[0050] Example 9

[0051] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method is referred to Example 1. The difference from Example 1 is that the inhibitor is a compound of sodium phosphate, water glass and tannic acid in a mass ratio of 1:2:3, and the dosage is 1200g / t. The targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (d) in solvent N,N-dimethylformamide, and nicotinic acid is dissolved in solvent ethanol to obtain a 5wt% solution 2, and the solution 1 and solution 2 are mixed in a molar ratio of bipyridylium salt (b) to p-hydroxybenzoic acid of 2:1, and the dosage is 600g / t. The dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 2:3:1, and the dosage is 1%. The foaming agent is pine oil, and the dosage is 15g / t. The recovery rate of barite after flotation is 95%, and the density is 4.3g·cm -3 .

[0052] Example 10

[0053] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method is referred to Example 1. The difference from Example 1 is that the inhibitor is a compound of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, and the dosage is 800g / t. The targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (e) in solvent N, N-dimethylformamide, and 6-chloronicotinic acid is dissolved in solvent ethanol to obtain a 5wt% solution 2, and the bipyridylium salt (e) and 6-chloronicotinic acid are mixed with solution 1 and solution 2 in a molar ratio of 2:1, and the dosage is 400g / t. The dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, and the dosage is 0.25%. The foaming agent is pine oil, and the dosage is 10g / t. The recovery rate of barite after flotation is 93%, and the density is 4.4g·cm -3 .

[0054] Embodiment 11

[0055] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method is referred to Example 1. The difference from Example 1 is that the inhibitor is a compound of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, and the dosage is 800g / t. The targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (f) in solvent N,N-dimethylformamide, and 6-chloronicotinic acid is dissolved in solvent ethanol to obtain a 5wt% solution 2, and the bipyridylium salt (f) and 6-chloronicotinic acid are mixed with solution 1 and solution 2 in a molar ratio of 2:1, and the dosage is 400g / t. The dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, and the dosage is 0.25%. The foaming agent is pine oil, and the dosage is 5g / t. The recovery rate of barite after flotation is 96%, and the density is 4.4g·cm -3 .

[0056] Example 12

[0057] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method is referred to Example 1. The difference from Example 1 is that the inhibitor is a compound obtained by mixing sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, and the dosage is 900g / t; the targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (a) and bipyridylium salt (f) in a solvent N,N-dimethylformamide to obtain a 5wt% solution; 6-chloronicotinic acid is dissolved in a solvent ethanol to obtain The solution 2 is prepared by mixing solution 1 and solution 2 in a molar ratio of 1:1:1 of bipyridylium salt (a), bipyridylium salt (f) and 6-chloronicotinic acid, with a dosage of 400 g / t; the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, with a dosage of 0.25%; the foaming agent is pine oil, with a dosage of 5 g / t; the recovery rate of barite after flotation is 98%, and the density is 4.4 g·cm -3 .

[0058] Example 13

[0059] In this embodiment, the treatment object is diesel-based rock cuttings, and the treatment method is referred to Example 1. The difference from Example 1 is that the inhibitor is a compound obtained by mixing sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, and the dosage is 900g / t; the targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (c) and bipyridylium salt (f) in a solvent N,N-dimethylformamide to obtain a 5wt% solution; 6-chloronicotinic acid is dissolved in a solvent ethanol to obtain The solution 2 is prepared by mixing solution 1 and solution 2 in a molar ratio of 1:1:1 of bipyridylium salt (c), bipyridylium salt (f) and 6-chloronicotinic acid, with a dosage of 400 g / t; the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, with a dosage of 0.25%; the foaming agent is pine oil, with a dosage of 10 g / t; the recovery rate of barite after flotation is 95%, and the density is 4.2 g·cm -3 .

[0060] Embodiment 14

[0061] In this embodiment, the treatment object is diesel-based rock chips. The treatment method refers to Example 1, which is different from Example 1 in that: the tailings remaining after flotation are dried at 105°C for 4 hours, and after drying, the tailings, bauxite and potassium feldspar are mixed in a mass ratio of 2:5:1, ball milled and sieved to obtain a mixture below 45 μm, and polyvinyl alcohol solution is added to the mixture in a mass ratio of polyvinyl alcohol solution (3wt%) to the mixture of 1:7, fully mixed and granulated, and naturally dried and sieved (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, which is sent to a resistance furnace for sintering at a sintering temperature of 1150°C and a heating rate of 5°C / min. After reaching the temperature, it is kept for 2 hours, and the furnace is stopped for cooling to obtain proppant clinker with corresponding mesh numbers (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh), wherein the volume density of the 20 / 40 mesh product is 1.30 g·cm -3 The crushing rate at 35MPa is 10.2%, and the volume density of 30 / 50 mesh product is 1.28g·cm -3 The crushing rate is 8.25% at 35MPa, and the volume density of 40 / 70 mesh product is 1.42g·cm -3 , the crushing rate is 7.24% at 35MPa.

[0062] Embodiment 15

[0063] In this embodiment, the treatment object is diesel-based rock chips. The treatment method is referred to Example 1. The difference from Example 1 is that the tailings remaining after flotation are dried at 105°C for 4 hours. After drying, the tailings, bauxite, and potassium feldspar are mixed in a mass ratio of 1.5:7:2, ball milled, and sieved to obtain a mixture below 45μm. Polyvinyl alcohol solution is added to the mixture in a mass ratio of 1:8 of polyvinyl alcohol solution (4wt%) to the mixture, fully mixed, granulated, and naturally dried. After sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, which is sent to a resistance furnace for sintering. The sintering temperature is 1300°C, the heating rate is 8°C / min, and the temperature is kept for 2 hours after reaching the temperature. After stopping the furnace for cooling, the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker is obtained. Among them, the volume density of the 20 / 40 mesh product is 1.34g·cm -3 , the crushing rate at 35MPa is 6.30%; the volume density of 30 / 50 mesh product is 1.38g·cm -3 , the crushing rate at 35MPa is 6.92%; the volume density of 40 / 70 mesh product is 1.32g·cm -3 , the crushing rate is 6.54% at 35MPa.

[0064] Example 16

[0065] In this embodiment, the treatment object is diesel-based rock chips. The treatment method is referred to Example 1. The difference from Example 1 is that the tailings remaining after flotation are dried at 105°C for 4 hours. After drying, the tailings, bauxite, and potassium feldspar are mixed in a mass ratio of 3:7:2, ball milled, and sieved to obtain a mixture below 45μm. Polyvinyl alcohol solution is added to the mixture in a mass ratio of 1:10 of polyvinyl alcohol solution (5wt%) to the mixture, fully mixed, granulated, and naturally dried. After sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, which is sent to a resistance furnace for sintering. The sintering temperature is 1200°C, the heating rate is 10°C / min, and the temperature is kept for 3 hours after reaching the temperature. After stopping the furnace and cooling, the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker is obtained. Among them, the volume density of the 20 / 40 mesh product is 1.29g·cm -3 , the crushing rate is 7.25% at 35MPa; the volume density of 30 / 50 mesh product is 1.33g·cm -3 , the crushing rate at 35MPa is 7.08%; the volume density of 40 / 70 mesh product is 1.23g·cm -3 , the crushing rate is 7.36% at 35MPa.

[0066] Embodiment 17

[0067] The white oil-based cuttings were crushed to less than 75 μm and transported to a three-stage countercurrent extraction system, and a countercurrent extractant was added at a liquid-solid ratio of 3:1. The extractant was prepared by compounding white oil, methyl ethyl ketone, sodium silicate and water at a mass ratio of 45:15:0.3:25. The extraction temperature was 25°C, the single-stage extraction time was 25 minutes, and the stirring speed was 450 r / min. After extraction, solid-liquid separation was performed by centrifugation at a centrifugal speed of 3000 r·min -1 The obtained water phase is recycled to the countercurrent extraction stage. 90% of the obtained oil phase enters the countercurrent extraction stage, and 10% is used to mix the drilling fluid. The solid phase obtained by centrifugation has an oil content of 0.27% and enters the flotation stage for the extraction of barite.

[0068] The solid phase obtained by centrifugation was ground to less than 50 μm, and added to an aqueous solution containing an inhibitor (sodium phosphate, water glass, and tannic acid were mixed in a mass ratio of 1:1:2, with an amount of 900 g / t), a targeted barite collector (a 5 wt% solution 1 was obtained by dissolving bipyridylium salt (a) in solvent N,N-dimethylformamide, and a 5 wt% solution 2 was obtained by dissolving 6-chloronicotinic acid in solvent ethanol, and a molar ratio of bipyridylium salt (a) to 6-chloronicotinic acid was 1:1.5). Solution 1 and solution 2 were mixed to obtain a flotation system of a targeted barite collector (dosage is 500 g / t), a dispersant (sodium pyrophosphate, sodium hexametaphosphate, and water glass are compounded in a mass ratio of 1:2:1, with a dosage of 0.35%), and a frother (pine oil, with a dosage of 10 g / t). The flotation temperature was controlled at 35 °C, the flotation time was 60 min, and the pulp concentration was 15%. After flotation, the recovery rate of barite was 95%, and the density was 4.0 g cm -3 , the flotation tailings enter the proppant preparation stage.

[0069] The flotation tailings are dried at 105°C for 3 hours, and after drying, the tailings, bauxite, and potassium feldspar are mixed in a mass ratio of 2:5:2, ball milled, and sieved to obtain a mixture below 45 μm, and polyvinyl alcohol solution is added to the mixture in a mass ratio of polyvinyl alcohol solution (4wt%) to the mixture of 1:7, mixed, granulated, naturally dried, sieved (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh), and the raw material of the proppant is obtained, and sent to the resistance furnace for sintering, the sintering temperature is 1280°C, the heating rate is 5°C / min, and the temperature is kept for 2.5 hours after reaching the temperature. After stopping the furnace for cooling, the corresponding mesh number (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) of the proppant clinker is obtained. Among them, the volume density of the 20 / 40 mesh product is 1.26g·cm -3 , the crushing rate at 35MPa is 9.24%; the volume density of 30 / 50 mesh product is 1.30g·cm -3 , the crushing rate at 35MPa is 7.86%; the volume density of 40 / 70 mesh product is 1.40g·cm -3 , the crushing rate is 6.31% at 35MPa.

[0070] Embodiment 18

[0071] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method refers to Example 17. The difference from Example 17 is that the extractant is obtained by compounding white oil, methyl ethyl ketone, sodium silicate, and water in a mass ratio of 40:10:0.2:20, the extraction temperature is 35°C, the single-stage extraction time is 20min, the stirring speed is 400r / min, and the oil content of the tailings after extraction is 0.25%.

[0072] Embodiment 19

[0073] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method refers to Example 18. The difference from Example 18 is that the extractant is obtained by compounding white oil, methyl ethyl ketone, sodium silicate, and water in a mass ratio of 60:20:0.5:30, the extraction temperature is 40°C, the single-stage extraction time is 35min, the stirring speed is 500r / min, and the oil content of the tailings after extraction is 0.20%.

[0074] Embodiment 20

[0075] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method refers to Example 18. The difference from Example 18 is that the extractant is obtained by compounding white oil, methyl ethyl ketone, sodium silicate, and water in a mass ratio of 45:15:0.3:25, the extraction temperature is 10°C, the single-stage extraction time is 25min, the stirring speed is 500r / min, and the oil content of the tailings after extraction is 0.35%.

[0076] Embodiment 21

[0077] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method is referred to Example 17, which is different from Example 17 in that: the inhibitor is a compound of sodium phosphate, water glass, and tannic acid in a mass ratio of 1:1.5:3, and the dosage is 800g / t; the targeted barite collector is a solution 1 obtained by dissolving bipyridylium salt (f) in solvent N,N-dimethylformamide, and oxalic acid is dissolved in solvent ethanol to obtain a 5wt% solution 2, and the bipyridylium salt (f) and oxalic acid are mixed with solution 1 and solution 2 in a molar ratio of 2:1, and the dosage is 400g / t; the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1:1:3, and the dosage is 0.25%; the foaming agent is pine oil, and the dosage is 8g / t. The recovery rate of barite after flotation is 96%, and the density is 4.2g·cm -3 .

[0078] Embodiment 22

[0079] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method is referred to Example 17, which is different from Example 17 in that: the targeted barite collector is a solution 1 of 5 wt% obtained by dissolving bipyridylium salt (a) and bipyridylium salt (f) in solvent N, N-dimethylformamide, and 6-chloronicotinic acid is dissolved in solvent ethanol to obtain a solution 2 of 5 wt%, bipyridylium salt (a), bipyridylium salt (f) and 6-chloronicotinic acid are mixed with solution 1 and solution 2 in a molar ratio of 0.5:1:1, and the dosage is 500 g / t, the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1.5:1:2, and the dosage is 0.75%, and the foaming agent is pine oil, and the dosage is 12 g / t. The recovery rate of barite after flotation is 98%, and the density is 4.4 g·cm-3 .

[0080] Embodiment 23

[0081] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method refers to Example 17, which is different from Example 17 in that: the targeted barite collector is a solution 1 of 5 wt% obtained by dissolving bipyridylium salt (a) and bipyridylium salt (f) in solvent N, N-dimethylformamide, and a solution 2 of 5 wt% obtained by dissolving trimesic acid in solvent ethanol, and the solution 1 and the solution 2 are mixed in a molar ratio of bipyridylium salt (a), bipyridylium salt (f) and trimesic acid of 1:1:2, and the dosage is 600 g / t, the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1.5:1:2, and the dosage is 0.75%, and the foaming agent is pine oil, and the dosage is 15 g / t. The recovery rate of barite after flotation is 97%, and the density is 4.3 g·cm -3 .

[0082] Embodiment 24

[0083] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method is referred to Example 17. The difference from Example 17 is that: the targeted barite collector is a solution 1 of 5 wt% obtained by dissolving bipyridylium salt (a) and bipyridylium salt (c) in solvent N, N-dimethylformamide, and a solution 2 of 5 wt% obtained by dissolving trimesic acid in solvent ethanol, and the solution 1 and the solution 2 are mixed in a molar ratio of bipyridylium salt (a), bipyridylium salt (c) and trimesic acid of 1:1:2, and the dosage is 600 g / t, the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1.5:1:2, and the dosage is 0.75%, and the foaming agent is pine oil, and the dosage is 15 g / t. The recovery rate of barite after flotation is 93%, and the density is 4.0 g·cm -3 .

[0084] Embodiment 25

[0085] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method refers to Example 17, which is different from Example 17 in that: the targeted barite collector is a solution 1 of 5 wt% obtained by dissolving bipyridylium salt (a) and bipyridylium salt (e) in solvent N, N-dimethylformamide, and a solution 2 of 5 wt% obtained by dissolving trimesic acid in solvent ethanol, and the solution 1 and the solution 2 are mixed in a molar ratio of bipyridylium salt (a), bipyridylium salt (e) and trimesic acid of 1:1:2, and the dosage is 600 g / t, the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1.5:1:2, and the dosage is 0.75%, and the foaming agent is pine oil, and the dosage is 5 g / t. The recovery rate of barite after flotation is 92%, and the density is 4.1 g·cm -3 .

[0086] Embodiment 26

[0087] In this embodiment, the treatment object is white oil-based rock cuttings, and the treatment method refers to Example 17, which is different from Example 17 in that: the targeted barite collector is a solution 1 of 5 wt% obtained by dissolving bipyridylium salt (b) and bipyridylium salt (f) in solvent N, N-dimethylformamide, and p-hydroxybenzoic acid is dissolved in solvent ethanol to obtain a solution 2 of 5 wt%, and bipyridylium salt (b), bipyridylium salt (f) and p-hydroxybenzoic acid are mixed with solution 1 and solution 2 in a molar ratio of 1:1:2, and the dosage is 600 g / t, the dispersant is a compound of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1:1:1, and the dosage is 1%, and the foaming agent is pine oil, and the dosage is 10 g / t. The recovery rate of barite after flotation is 90%, and the density is 4.2 g·cm -3 .

[0088] Embodiment 27

[0089] In this embodiment, the treatment object is white oil-based rock cuttings. The treatment method is referred to Example 17, and the difference from Example 17 is that: the flotation tailings are dried at 105°C for 4 hours, and after drying, the tailings, bauxite, and potassium feldspar are mixed in a mass ratio of 3:5:1, ball milled, and sieved to obtain a mixture below 45μm, and polyvinyl alcohol solution is added to the mixture in a mass ratio of polyvinyl alcohol solution (4wt%) to the mixture of 1:8, mixed, granulated, and naturally dried. After sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, which is sent to a resistance furnace for sintering. The sintering temperature is 1200°C, the heating rate is 10°C / min, and the temperature is kept for 3 hours after reaching the temperature. After stopping the furnace for cooling, the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker is obtained. Among them. The volume density of the 20 / 40 mesh product is 1.33g·cm -3, the crushing rate is 9.8% at 35MPa; the volume density of 30 / 50 mesh product is 1.25g·cm -3 , the crushing rate is 8.74% at 35MPa; the volume density of 40 / 70 mesh product is 1.36g·cm -3 , the crushing rate is 9.12% at 35MPa.

[0090] Embodiment 28

[0091] In this embodiment, the treatment object is white oil-based rock cuttings. The treatment method is referred to Example 17, and the difference from Example 17 is that: the flotation tailings are dried at 105°C for 4 hours, and after drying, the tailings, bauxite, and potassium feldspar are mixed in a mass ratio of 1.5:7:2, ball milled, and sieved to obtain a mixture below 45μm, and polyvinyl alcohol solution is added to the mixture in a mass ratio of 1:8 of polyvinyl alcohol solution (4wt%) to the mixture, mixed, granulated, and naturally dried. After sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, which is sent to a resistance furnace for sintering, the sintering temperature is 1300°C, the heating rate is 8°C / min, and the temperature is kept for 2 hours after reaching the temperature. After stopping the furnace for cooling, the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker is obtained. Among them, the volume density of the 20 / 40 mesh product is 1.38g·cm -3 , the crushing rate at 35MPa is 7.22%; the volume density of 30 / 50 mesh product is 1.35g·cm -3 , the crushing rate at 35MPa is 7.06%; the volume density of 40 / 70 mesh product is 1.41g·cm -3 , the crushing rate is 7.98% at 35MPa.

[0092] It can be seen from the above examples 1-28 that the developed oil-based rock cuttings high-efficiency degreasing agent can effectively reduce the oil content of oil-based rock cuttings to less than 1% under normal temperature conditions of 15-40°C. Example 6 further proves that under a low temperature environment of 10°C, the oil content can still be lower than 1% after being treated with the invented degreasing agent. Comparing Example 2, Example 4 and Example 5, it can be seen that temperature has a certain influence on the degreasing effect of the degreasing agent, and its degreasing effect is better in the temperature range of 35-40°C. Further comparing Example 1, Example 2 and Example 4, and Example 19 and Example 20, it can be seen that as the proportion of diesel or white oil and methyl ethyl ketone in the degreasing agent increases, the degreasing effect increases accordingly, but as the proportion of water decreases, the difficulty of subsequent centrifugation increases. Taking into account both degreasing and centrifugal effects, the best use range of the degreasing agent is diesel or white oil, methyl ethyl ketone, sodium silicate, and water are compounded according to a mass ratio of 45-55:15-20:0.2-0.3:20-25.

[0093] It can be seen from the above examples 1-28 that the developed targeted barite collector can achieve a barite recovery rate of ≥90% and a density of ≥4.0 g·cm -3 , which can meet the requirements of well site reuse. By comparing Example 1, Example 7, Example 8, Example 9, Example 10, and Example 11, it can be seen that the effect of the targeted collector prepared by the participation of bipyridylium salt (a) and bipyridylium salt (f) is better than the effect of the targeted collector prepared by the participation of bipyridylium salt (b), bipyridylium salt (c), bipyridylium salt (d), and bipyridylium salt (a). It can be seen from Example 12 and Example 13 that the effect of the targeted collector obtained by compounding two or more bipyridylium salts is better than the effect of the targeted collector prepared by the participation of a single bipyridylium salt.

Claims

1. A countercurrent extractant, characterized in that The invention comprises components in the following mass ratio: the mass ratio of the extraction target oil, methyl ethyl ketone, sodium silicate and water is 40-60:10-20:0.2-0.5:20-30.

2. The countercurrent extractant according to claim 1, characterized in that The mass ratio of the extraction target oil, methyl ethyl ketone, sodium silicate and water is 45-55:15-20:0.2-0.3:20-25.

3. The countercurrent extractant according to claim 1, characterized in that The extraction target oil is diesel or white oil.

4. A method for preparing a countercurrent extractant according to any one of claims 1 to 3, characterized in that: The extraction target oil, methyl ethyl ketone, sodium silicate and water are mixed according to a mass ratio.

5. A method for extracting oil from oil-based rock cuttings, characterized in that: include: The oil-based rock cuttings are extracted using the countercurrent extractant described in any one of claims 1 to 3.

6. The method for extracting oil from oil-based rock cuttings according to claim 5, characterized in that: include: Add oil-based rock cuttings and the above countercurrent extractant in a liquid-to-solid ratio of 3-5:1, and extract at 15-40°C.

7. The method for extracting oil from oil-based rock cuttings according to claim 6, characterized in that: The extraction is a three-stage countercurrent extraction, the single-stage extraction time is 20-35 minutes, and the stirring speed is 350-500 r / min.

8. The method for extracting oil from oil-based rock cuttings according to claim 5, characterized in that: include: After the extraction step, liquid-solid separation is performed to obtain a solid phase and a liquid phase, and the liquid phase is subjected to oil-water separation.

9. A comprehensive utilization process of oil-based rock cuttings, characterized in that: A method for extracting oil from oil-based rock cuttings comprising any one of claims 5-8.

10. The comprehensive utilization process of oil-based rock cuttings according to claim 9, characterized in that: The solid phase obtained by centrifuging the oil-containing oil extraction method of the oil-based rock cuttings according to any one of claims 5 to 8 is extracted using a barite extraction method, and the remaining flotation tailings.

11. The comprehensive utilization process of oil-based rock cuttings according to claim 10, characterized in that: The barite extraction method uses a flotation system comprising a targeted barite collector, an inhibitor, a dispersant and a frother for flotation; the inhibitor is sodium phosphate, water glass and tannic acid mixed in a mass ratio of 1:1-2:1-3, and the dosage is 800-1200 g / t; the frother is pine oil, and the dosage is 5-15 g / t; the dispersant is sodium pyrophosphate, sodium hexametaphosphate and water glass mixed in a mass ratio of 1-2:1-3:1, and the dosage is 0.25-1%; the targeted barite collector comprises bipyridylium salt and carboxylic acid, and the bipyridylium salt is: The carboxylic acid is a mixture of any one or more of oxalic acid, p-hydroxybenzoic acid, trimesic acid, nicotinic acid, and 6-chloronicotinic acid, and the molar ratio of the bipyridylium salt to the carboxylic acid is 1:2-2:1.

Images