Oil-based reverse cuttings extractant, preparation and use thereof

Abstract

The application discloses a countercurrent extractant, which comprises the following components in a mass ratio: 40-60 of target oil, 10-20 of methyl ethyl ketone, 0.2-0.5 of sodium silicate and 20-30 of water. The application also discloses preparation and application thereof. The application provides an oil extraction process by low-temperature countercurrent extraction, a flotation method for extracting barite minerals from oil-based drilling cuttings, a method for processing oil-based drilling cuttings by using flotation tailings to prepare proppants, and development of high-efficiency extractants and flotation agents. After countercurrent extraction, the oil content of the oil-based drilling cuttings can be reduced to below 0.3%.

Description

TECHNICAL FIELD

[0001] The present application relates to oil-based drilling debris counter-current extractant and its preparation and application. BACKGROUND

[0002] Oil-based drilling fluid is widely used in shale gas, tight gas and other unconventional oil and gas resource development field, which is composed of mineral oil, water, weighting agent, organic clay and various oil-soluble chemical treatment agent, has the advantages of high temperature resistance, salt and calcium corrosion resistance, is conducive to wellbore stability, good lubricity, small damage to oil and gas layer, etc. In drilling operation, the oil-based drilling fluid carries the drilling debris drilled from the formation back to the ground, and after being treated by the solid control system on the well site, the upper phase is retained and the lower phase is recycled. The main components of the oil-based drilling debris are mineral oil, organic compounds such as phenol and various inorganic minerals. If the mineral oil and organic compounds contained therein are not properly treated and discharged, they will pollute the soil, surface and groundwater, and directly or indirectly cause harm to plants, animals, human health and the surrounding ecological environment.

[0003] The oil-based drilling debris has an average oil content of about 25-40%, which has considerable economic value. The existing technology mainly uses high-temperature energy-consuming heat treatment to collect the oil in the oil-based drilling debris. The oil content of the oil-removed 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

[0004] In order to further improve the environmental protection treatment and resource comprehensive utilization of oil-based drilling debris, the present application is made.

[0005] The target oil referred to in the present application is the type of base oil extracted from the oil-based drilling debris by the counter-current extractant, such as diesel oil for diesel oil-based drilling debris and white oil for white oil-based drilling debris.

[0006] As an aspect of the present application, the counter-current extractant comprises the following components in the mass ratio: 40-60:10-20:0.2-0.5:20-30 of the target oil (diesel oil or white oil), methyl ethyl ketone, sodium silicate and water, preferably 45-55:15-20:0.2-0.3:20-25.

[0007] As another aspect of the present application, the method for preparing the above-mentioned counter-current extractant is to mix the target oil (diesel oil or white oil), methyl ethyl ketone, sodium silicate and water in the mass ratio.

[0008] As another aspect of the present application, the method for extracting oil from oil-based drilling debris comprises using the above-mentioned counter-current extractant to extract the oil-based drilling debris.

[0009] In specific embodiments, the method comprises the following steps:

[0010] The oil-based cuttings and the countercurrent extractant are added in a ratio of 3-5:1 liquid to solid, and extraction is carried out at 15-40°C.

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

[0012] In specific embodiments, the method further comprises 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 specific embodiments, the method further comprises recycling the aqueous phase obtained after oil-water separation to the countercurrent extraction step, and 80-90% of the oil phase obtained is introduced into the countercurrent extraction step.

[0014] As another aspect of the present application, a comprehensive utilization process for oil-based cuttings is provided, which comprises the oil extraction method described above.

[0015] In specific embodiments, the oil extraction method described above uses the barite extraction method to extract the solid phase obtained by centrifugation, and the residual flotation tailings. The barite extraction method uses a flotation system comprising a barite-targeting collector, an inhibitor, a dispersant, and a frother; the inhibitor is a mixture of sodium phosphate, water glass, and tannic acid in a mass ratio of 1:1-2:1-3, and the amount used is 800-1200 g / t; the frother is pine oil, and the amount used is 5-15 g / t; the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1-2:1-3:1, and the amount used is 0.25-1%; the barite-targeting collector comprises a mixture of any one or more of the following:

[0016]

[0017]

[0018] and any one or more of the following: a mixture; 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 bipyridinium salt to the carboxylic acid is 1:2-2:1.

[0019] In specific embodiments, the comprehensive utilization process for oil-based cuttings uses the barite extraction method described above to extract the solid phase obtained by centrifugation in the oil extraction method described above, and the residual flotation tailings.

[0020] In specific embodiments, the comprehensive utilization process for oil-based cuttings further comprises using the flotation tailings to prepare proppants.

[0021] In specific embodiments, the preparation of proppant from the flotation tailings refers to: drying the flotation tailings at 105 DEG C for 3-4h, mixing the tailings, bauxite and potassium feldspar after drying in a mass ratio of 2-3:5-7:1-2, ball milling and sieving to obtain a mixture below 45 μm, adding polyvinyl alcohol solution (3-5wt%) to the mixture in a mass ratio of 1:7-10, fully mixing and granulating, sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) after natural drying to obtain proppant raw material, and sintering in an electric resistance furnace, with a sintering temperature of 1150-1300 DEG C, a heating rate of 5-10 DEG C / min, a residence time of 2-3h after reaching the temperature, and a corresponding mesh size (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant product obtained after cooling.

[0022] The present application provides a low-temperature countercurrent extraction process for oil extraction, and a flotation method for extracting barite minerals from oil-free solid phase, and an oil-based rock debris resource processing method using flotation tailings to prepare proppant, and the development of high-efficiency extractants and flotation agents. After countercurrent extraction, the oil content of the oil-based rock debris tailings can be reduced to below 0.3%; further extracted by flotation method, the recovery rate of barite can reach more than 95%, and the proppant prepared from the flotation tailings meets the requirements of 35MPa specification products in SY / T5108-2014, realizing the full resource utilization of oil-based rock debris.

[0023] The process of the present application is proposed in view of the characteristics of oil-based rock debris rich in white oil or diesel oil (collectively referred to as base oil), barite minerals and other useful components, and adopts the technical route of "countercurrent extraction of base oil - flotation extraction of barite - tailings sintering of proppant", realizing the deep resource utilization of oil-based rock debris. The recovered base oil can be used for back-mixing drilling fluid, the extracted barite can be used as a weighting agent for drilling fluid, and the remaining flotation tailings can be used as raw material for preparing fracturing proppant, achieving the dual goals of harmlessness and resource utilization, and solving the environmental protection problem that has plagued oil and gas field development enterprises. The present application provides a resource processing method for low-temperature countercurrent extraction of oil and flotation extraction of barite, and uses the flotation tailings to prepare fracturing proppant, and develops high-efficiency countercurrent extractants for base oil and targeted barite collectors, which better realizes the extraction of oil and minerals from oil-based rock debris, and the preparation of proppant from tailings, and more thoroughly realizes the resource utilization of oil-based rock debris. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is the oil-based drilling waste resource processing method flow chart provided by the present application.

[0025] Figure 2 is the operation schematic diagram of the countercurrent extraction unit in the oil-based drilling waste resource processing flow chart provided by the present application. DETAILED DESCRIPTION

[0026] The embodiments of the present application are described in detail as follows: The embodiments of the present application are implemented on the premise of the technical solutions of the present application, and detailed implementation manners and processes are given, but the protection scope of the present application is not limited to the following embodiments. The process parameters not specified in the following embodiments are usually according to conventional conditions.

[0027] The endpoints of the ranges and any numerical values included in the disclosure are not limited to the precise values stated. These ranges and values should be construed as being approximate. Any numerical value, however, can include only one value, or a range between two values, which values include any value between the two endpoints. Any numerical value can include only one value, or a range between two values, which values include any value between the two endpoints.

[0028] The corresponding operation steps of the following embodiments can refer to the attached Figure 1 and the attached Figure 2 for implementation.

[0029] The structure formula of the bipyridinium salt used in the embodiments of the present application is as follows:

[0030]

[0031]

[0032] Embodiment 1

[0033] The diesel-based drilling waste is crushed to below 75 μm, transported to a three-stage countercurrent extraction system, and a countercurrent extraction agent is added in a liquid-solid ratio of 3:1, the countercurrent extraction agent is obtained by compounding diesel, methyl ethyl ketone, sodium silicate and water in a mass ratio of 45:15:0.3:25, the extraction temperature is 25℃, the single-stage extraction time is 25 min, and the stirring speed is 450 r / min. After extraction, solid-liquid separation is performed by centrifugation, the centrifugal rate is 3000 r·min -1 The liquid phase is further subjected to oil-water separation, the obtained water phase is recycled to the countercurrent extraction link. The obtained oil phase, 90% enters the countercurrent extraction link, and 10% is used for re-compounding drilling fluid. The oil content of the solid phase obtained by centrifugation is 0.25%, which enters the flotation link for extraction of barite.

[0034] The solid phase obtained by centrifugation is ground to below 50 μm and added to a flotation system of beneficiation reagents with the addition of inhibitors (sodium phosphate, water glass and tannic acid compounded in a mass ratio of 1:1:2, with a dosage of 900 g / t), targeted barite collector (dissolution of bipyridinium salt (a) in solvent N,N-dimethylformamide to obtain a 5 wt% solution 1, dissolution of oxalate in solvent ethanol to obtain a 5 wt% solution 2, mixing solution 1 and solution 2 in a molar ratio of bipyridinium salt (a) to oxalate of 1:1.5 to obtain a targeted barite collector, with a dosage of 500 g / t), dispersant (sodium pyrophosphate, sodium hexametaphosphate and water glass compounded in a mass ratio of 1:2:1, with a dosage of 0.35%), foaming agent (pine oil, with a dosage of 10 g / t), with the control of the flotation temperature at 35℃, the flotation time of 60 min and the pulp concentration of 15%, after flotation, the recovery rate of barite is 96%, the density is 4.2 g·cm -3 , and the flotation tailings enter the proppant preparation link.

[0035] The flotation tailings are dried at 105℃ for 3 h, 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 (4 wt%) is added to the mixture in a mass ratio of 1:7, mixed, granulated, naturally air-dried and sieved (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, which is sent into an electric resistance furnace for sintering, with a sintering temperature of 1280℃, a heating rate of 5℃ / min, a residence time of 2.5 h after reaching the temperature, and the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker is obtained after the furnace is stopped and cooled. Among them, the volume density of the 20 / 40 mesh product is 1.26 g·cm -3 , the breakage rate at 35 MPa is 9.24%; the volume density of the 30 / 50 mesh product is 1.30 g·cm -3 , the breakage rate at 35 MPa is 7.86%; the volume density of the 40 / 70 mesh product is 1.40 g·cm -3 , the breakage rate at 35 MPa is 6.31%.

[0036] Example 2

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

[0038] Example 3

[0039] The processing object in the embodiment is diesel-based drill cuttings, and the processing method refers to embodiment 2, and the difference from embodiment 2 is that the extraction temperature is 15 ℃, the single-stage extraction time is 20 min, the stirring speed is 350 r / min, and the oil content of the tailings after extraction is 0.5%.

[0040] Embodiment 4

[0041] The processing object in the embodiment is diesel-based drill cuttings, and the processing method refers to embodiment 2, and the difference from embodiment 2 is that the extraction temperature is 15 ℃, the single-stage extraction time is 20 min, the stirring speed is 350 r / min, and the oil content of the tailings after extraction is 0.5%.

[0042] Embodiment 5

[0043] The processing object in the embodiment is diesel-based drill cuttings, and the processing method refers to embodiment 2, and the difference from embodiment 2 is that the extraction temperature is 15 ℃, the single-stage extraction time is 20 min, the stirring speed is 350 r / min, and the oil content of the tailings after extraction is 0.5%.

[0044] Embodiment 6

[0045] The processing object in the embodiment is diesel-based drill cuttings, and the processing method refers to embodiment 2, and the difference from embodiment 2 is that the extraction temperature is 15 ℃, the single-stage extraction time is 20 min, the stirring speed is 350 r / min, and the oil content of the tailings after extraction is 0.5%.

[0046] Embodiment 7

[0047] The processing object in the embodiment is diesel-based drill cuttings, and the processing method refers to embodiment 1, and the difference from embodiment 1 is that the inhibitor is a mixture of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, the dosage is 800 g / t, the target barite collector is a 5wt% solution 1 obtained by dissolving bipyridinium salt (b) in solvent N,N-dimethylformamide, a 5wt% solution 2 obtained by dissolving p-hydroxybenzoic acid in solvent ethanol, the mixture of solution 1 and solution 2 is obtained by mixing bipyridinium salt (b) and p-hydroxybenzoic acid in a molar ratio of 2:1, the dosage is 400 g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:1:3, the dosage is 0.25%, and the foaming agent is pine oil, the dosage is 8 g / t. After flotation, the recovery rate of barite is 95%, and the density is 4.0 g·cm -3 .

[0048] Example 8

[0049] The processing object in the example is diesel-based drill cuttings, and the processing method is referred to Example 1, with the difference from Example 1 being that the depressant is a mixture of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1:1, the dosage being 1200 g / t, the targeted barite collector is a solution 1 of 5wt% of bipyridinium salt (c) dissolved in solvent N,N-dimethylformamide, a solution 2 of 5wt% of trimesic acid dissolved in solvent ethanol, the mixing of solution 1 and solution 2 being in a molar ratio of 1:2, the dosage being 600 g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:1:1, the dosage being 0.25%, and the frother is pine oil, the dosage being 5 g / t. After flotation, the recovery rate of barite is 90%, and the density is 4.1 g·cm -3 .

[0050] Example 9

[0051] The processing object in the example is diesel-based drill cuttings, and the processing method is referred to Example 1, with the difference from Example 1 being that the depressant is a mixture of sodium phosphate, water glass and tannic acid in a mass ratio of 1:2:3, the dosage being 1200 g / t, the targeted barite collector is a solution 1 of 5wt% of bipyridinium salt (d) dissolved in solvent N,N-dimethylformamide, a solution 2 of 5wt% of nicotinic acid dissolved in solvent ethanol, the mixing of solution 1 and solution 2 being in a molar ratio of 2:1, the dosage being 600 g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 2:3:1, the dosage being 1%, and the frother is pine oil, the dosage being 15 g / t. After flotation, the recovery rate of barite is 95%, and the density is 4.3 g·cm -3 .

[0052] Example 10

[0053] The processing object in the embodiment is diesel-based cuttings, and the processing method refers to embodiment 1. The difference from embodiment 1 is that the depressant is a mixture of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, the dosage is 800 g / t, the targeted barite collector is 5wt% solution 1 obtained by dissolving bipyridinium salt (e) in solvent N,N-dimethylformamide, 5wt% solution 2 obtained by dissolving 6-chloronicotinic acid in solvent ethanol, and the mixture of solution 1 and solution 2 obtained by mixing bipyridinium salt (e) and 6-chloronicotinic acid in a molar ratio of 2:1, the dosage is 400 g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, the dosage is 0.25%, the foaming agent is pine oil, and the dosage is 10 g / t. After flotation, the recovery rate of barite is 93%, and the density is 4.4 g·cm -3 .

[0054] Embodiment 11

[0055] The processing object in the embodiment is diesel-based cuttings, and the processing method refers to embodiment 1. The difference from embodiment 1 is that the depressant is a mixture of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, the dosage is 800 g / t, the targeted barite collector is 5wt% solution 1 obtained by dissolving bipyridinium salt (e) in solvent N,N-dimethylformamide, 5wt% solution 2 obtained by dissolving 6-chloronicotinic acid in solvent ethanol, and the mixture of solution 1 and solution 2 obtained by mixing bipyridinium salt (e) and 6-chloronicotinic acid in a molar ratio of 2:1, the dosage is 400 g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, the dosage is 0.25%, the foaming agent is pine oil, and the dosage is 10 g / t. After flotation, the recovery rate of barite is 93%, and the density is 4.4 g·cm -3 .

[0056] Embodiment 12

[0057] The treatment object in the embodiment is diesel-based drill cuttings, and the treatment method refers to that in Embodiment 1, except that: the depressant is a mixture of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, the dosage is 900 g / t, the targeted barite collector is a solution 1 obtained by dissolving bipyridinium salt (a) and bipyridinium salt (f) in solvent N,N-dimethylformamide to obtain a 5wt% solution, dissolving 6-chloronicotinic acid in solvent ethanol to obtain a 5wt% solution 2, mixing solution 1 and solution 2 in a molar ratio of 1:1:1 of bipyridinium salt (a), bipyridinium salt (f) and 6-chloronicotinic acid, the dosage is 400 g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, the dosage is 0.25%, the frother is pine oil, the dosage is 5 g / t, and the recovery rate of barite after flotation is 98%, the density is 4.4 g·cm -3 .

[0058] Embodiment 13

[0059] The treatment object in the embodiment is diesel-based drill cuttings, and the treatment method refers to that in Embodiment 1, except that: the depressant is a mixture of sodium phosphate, water glass and tannic acid in a mass ratio of 1:1.5:3, the dosage is 900 g / t, the targeted barite collector is a solution 1 obtained by dissolving bipyridinium salt (a) and bipyridinium salt (f) in solvent N,N-dimethylformamide to obtain a 5wt% solution, dissolving 6-chloronicotinic acid in solvent ethanol to obtain a 5wt% solution 2, mixing solution 1 and solution 2 in a molar ratio of 1:1:1 of bipyridinium salt (a), bipyridinium salt (f) and 6-chloronicotinic acid, the dosage is 400 g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1:3:1, the dosage is 0.25%, the frother is pine oil, the dosage is 5 g / t, and the recovery rate of barite after flotation is 98%, the density is 4.4 g·cm -3 .

[0060] Embodiment 14

[0061] The processing object in this embodiment is diesel-based drill cuttings, and the processing method refers to that in Embodiment 1, except that the tailings remaining after flotation are dried at 105℃ for 4h, and then mixed with bauxite and potassium feldspar at a mass ratio of 2:5:1, followed by ball milling, sieving, and obtaining a mixture below 45μm, adding polyvinyl alcohol solution (3wt%) to the mixture at a mass ratio of 1:7, fully mixing and granulating, and then sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) after natural drying to obtain proppant raw material, which is sent into an electric resistance furnace for sintering at a sintering temperature of 1150℃ and a heating rate of 5℃ / min, and then kept for 2h after reaching the temperature, and then cooled after stopping the furnace to obtain corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker. The volume density of the 20 / 40 mesh product is 1.30g·cm -3 , the breakage rate at 35MPa is 10.2%, the volume density of the 30 / 50 mesh product is 1.28g·cm -3 , the breakage rate at 35MPa is 8.25%, and the volume density of the 40 / 70 mesh product is 1.42g·cm -3 , the breakage rate at 35MPa is 7.24%.

[0062] Embodiment 15

[0063] The processing object in this embodiment is diesel-based drill cuttings, and the processing method refers to that in Embodiment 1, except that the tailings remaining after flotation are dried at 105℃ for 4h, and then mixed with bauxite and potassium feldspar at a mass ratio of 2:5:1, followed by ball milling, sieving, and obtaining a mixture below 45μm, adding polyvinyl alcohol solution (3wt%) to the mixture at a mass ratio of 1:7, fully mixing and granulating, and then sieving (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) after natural drying to obtain proppant raw material, which is sent into an electric resistance furnace for sintering at a sintering temperature of 1150℃ and a heating rate of 5℃ / min, and then kept for 2h after reaching the temperature, and then cooled after stopping the furnace to obtain corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker. The volume density of the 20 / 40 mesh product is 1.30g·cm -3 , the breakage rate at 35MPa is 6.30%; the volume density of the 30 / 50 mesh product is 1.38g·cm -3 , the breakage rate at 35MPa is 6.92%; and the volume density of the 40 / 70 mesh product is 1.32g·cm -3 , the breakage rate at 35MPa is 6.54%.

[0064] Embodiment 16

[0065] The processing object in this embodiment is diesel-based cuttings, and the processing method is as described in Embodiment 1, except that the tailings remaining after the flotation are dried at 105℃ for 4h, and then mixed with bauxite and potassium feldspar at a mass ratio of 3:7:2, ball-milled, sieved, and mixed with polyvinyl alcohol solution (5wt%) at a mass ratio of 1:10, and then granulated, naturally dried, sieved (15 / 30 mesh, 25 / 40 mesh, and 30 / 50 mesh), and then sintered in an electric resistance furnace at a sintering temperature of 1200℃ and a heating rate of 10℃ / min, and then cooled after 3h of residence at the sintering temperature, to obtain the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, and 40 / 70 mesh) proppant clinker. The volume density of the 20 / 40 mesh product is 1.29g·cm -3 , the breakage rate at 35MPa is 7.25%; the volume density of the 30 / 50 mesh product is 1.33g·cm -3 , the breakage rate at 35MPa is 7.08%; and the volume density of the 40 / 70 mesh product is 1.23g·cm -3 , the breakage rate at 35MPa is 7.36%.

[0066] Embodiment 17

[0067] The white oil-based cuttings are broken to 75μm or less, and then transported to a 3-stage countercurrent extraction system, and a countercurrent extraction agent is added at a liquid-solid ratio of 3:1, the extraction agent being compounded from white oil, methyl ethyl ketone, sodium silicate, and water at a mass ratio of 45:15:0.3:25, the extraction temperature being 25℃, the single-stage extraction time being 25min, and the stirring speed being 450r / min. After the extraction, the solid-liquid separation is performed by centrifugation at a centrifugal speed of 3000r·min -1 . The obtained water phase is reused in the countercurrent extraction step. 90% of the obtained oil phase is used in the countercurrent extraction step, and 10% is used to reconfigure the drilling fluid. The oil content of the solid phase obtained by centrifugation is 0.27%, which is used in the flotation step for extraction of barite.

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

[0069] The flotation tailings are dried at 105℃ for 3 h, and then mixed with bauxite and potassium feldspar at a mass ratio of 2:5:2. The mixture is ball milled and sieved to obtain a mixture below 45 μm. Polyvinyl alcohol solution (4 wt%) is added to the mixture at a mass ratio of 1:7, and then mixed, granulated, naturally dried, and sieved (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant green material. The proppant green material is sent into an electric resistance furnace for sintering at a sintering temperature of 1280℃ and a heating rate of 5℃ / min. After reaching the temperature, the proppant green material is kept for 2.5 h, and then cooled to obtain corresponding mesh proppant clinker (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh). The volume density of the 20 / 40 mesh product is 1.26 g·cm -3 , the breakage rate at 35 MPa is 9.24%; the volume density of the 30 / 50 mesh product is 1.30 g·cm -3 , the breakage rate at 35 MPa is 7.86%; and the volume density of the 40 / 70 mesh product is 1.40 g·cm -3 , the breakage rate at 35 MPa is 6.31%.

[0070] Example 18

[0071] In this example, the treatment object is white oil-based cuttings, and the treatment method is the same as that in Example 17, except that the extractant is compounded from white oil, methyl ethyl ketone, sodium silicate, and water at a mass ratio of 40:10:0.2:20, the extraction temperature is 35℃, the single-stage extraction time is 20 min, and the stirring speed is 400 r / min. After extraction, the oil content of the tailings is 0.25%.

[0072] Example 19

[0073] The processing object in the embodiment is white oil-based drill cuttings, and the processing method refers to embodiment 18. Different from embodiment 18, the extractant is compounded by white oil, methyl ethyl ketone, sodium silicate and water according to a mass ratio of 60:20:0.5:30, the extraction temperature is 40 DEG C, the single-stage extraction time is 35 min, the stirring speed is 500 r / min, and the tailings oil content after extraction is 0.20%.

[0074] Embodiment 20

[0075] The processing object in the embodiment is white oil-based drill cuttings, and the processing method refers to embodiment 18. Different from embodiment 18, the extractant is compounded by white oil, methyl ethyl ketone, sodium silicate and water according to a mass ratio of 45:15:0.3:25, the extraction temperature is 10 DEG C, the single-stage extraction time is 25 min, the stirring speed is 500 r / min, and the tailings oil content after extraction is 0.35%.

[0076] Embodiment 21

[0077] The processing object in the embodiment is white oil-based drill cuttings, and the processing method refers to embodiment 17. Different from embodiment 17, the inhibitor is compounded by sodium phosphate, water glass and tannic acid according to a mass ratio of 1:1.5:3, the dosage is 800 g / t, the targeted barite collector is a solution 1 of 5 wt% obtained by dissolving bipyridinium salt (f) in solvent N, N-dimethylformamide, a solution 2 of 5 wt% obtained by dissolving oxalic acid in solvent ethanol, and the solution 1 and the solution 2 are mixed according to a molar ratio of bipyridinium salt (f) to oxalic acid of 2:1, the dosage is 400 g / t, the dispersant is compounded by sodium pyrophosphate, sodium hexametaphosphate and water glass according to a mass ratio of 1:1:3, the dosage is 0.25%, and the frother is pine oil, the dosage is 8 g / t. After flotation, the recovery rate of barite is 96%, and the density is 4.2 g·cm -3 .

[0078] Embodiment 22

[0079] The processing object in the embodiment is white oil-based drill cuttings, and the processing method refers to embodiment 17. Different from embodiment 17, the targeted barite collector is a solution 1 of 5 wt% obtained by dissolving bipyridinium salt (a) and bipyridinium salt (f) in solvent N, N-dimethylformamide, a solution 2 of 5 wt% obtained by dissolving 6-chloronicotinic acid in solvent ethanol, and the solution 1 and the solution 2 are mixed according to a molar ratio of bipyridinium salt (a), bipyridinium salt (f) to 6-chloronicotinic acid of 0.5:1:1, the dosage is 500 g / t, the dispersant is compounded by sodium pyrophosphate, sodium hexametaphosphate and water glass according to a mass ratio of 1.5:1:2, the dosage is 0.75%, and the frother is pine oil, the dosage is 12 g / t. After flotation, the recovery rate of barite is 98%, and the density is 4.4 g·cm-3 .

[0080] Example 23

[0081] The processing object in this example is white oil-based cuttings, and the processing method refers to Example 17. The difference between Example 17 and this example is that the targeted barite collector is that bipyridinium salt (a) and bipyridinium salt (f) are dissolved in solvent N,N-dimethylformamide to obtain a 5wt% solution 1, and trimesic acid is dissolved in solvent ethanol to obtain a 5wt% solution 2. Solution 1 and solution 2 are mixed according to the molar ratio of bipyridinium salt (a), bipyridinium salt (f) and trimesic acid 1:1:2, and the obtained mixture is used in an amount of 600g / 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 obtained compound is used in an amount of 0.75%. The foaming agent is pine oil, and the amount used is 15g / t. After flotation, the recovery rate of barite is 97%, and the density is 4.3g·cm -3 .

[0082] Example 24

[0083] The processing object in this example is white oil-based cuttings, and the processing method refers to Example 17. The difference between Example 17 and this example is that the targeted barite collector is that bipyridinium salt (a) and bipyridinium salt (c) are dissolved in solvent N,N-dimethylformamide to obtain a 5wt% solution 1, and trimesic acid is dissolved in solvent ethanol to obtain a 5wt% solution 2. Solution 1 and solution 2 are mixed according to the molar ratio of bipyridinium salt (a), bipyridinium salt (c) and trimesic acid 1:1:2, and the obtained mixture is used in an amount of 600g / 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 obtained compound is used in an amount of 0.75%. The foaming agent is pine oil, and the amount used is 15g / t. After flotation, the recovery rate of barite is 93%, and the density is 4.0g·cm -3 .

[0084] Example 25

[0085] The processing object in this embodiment is white oil-based cuttings, and the processing method refers to embodiment 17. The difference between this embodiment and embodiment 17 is that the targeted barite collector is obtained by dissolving bipyridinium salt (a) and bipyridinium salt (e) in solvent N,N-dimethylformamide to obtain a 5wt% solution 1, dissolving trimesic acid in solvent ethanol to obtain a 5wt% solution 2, mixing solution 1 and solution 2 in a molar ratio of 1:1:2 of bipyridinium salt (a), bipyridinium salt (e) and trimesic acid, and using the obtained mixture in an amount of 600g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1.5:1:2, the amount is 0.75%, and the foaming agent is pine oil, the amount is 5g / t. After flotation, the recovery rate of barite is 92%, and the density is 4.1g·cm -3 .

[0086] Example 26

[0087] The processing object in this embodiment is white oil-based cuttings, and the processing method refers to embodiment 17. The difference between this embodiment and embodiment 17 is that the targeted barite collector is obtained by dissolving bipyridinium salt (a) and bipyridinium salt (e) in solvent N,N-dimethylformamide to obtain a 5wt% solution 1, dissolving trimesic acid in solvent ethanol to obtain a 5wt% solution 2, mixing solution 1 and solution 2 in a molar ratio of 1:1:2 of bipyridinium salt (a), bipyridinium salt (e) and trimesic acid, and using the obtained mixture in an amount of 600g / t, the dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate and water glass in a mass ratio of 1.5:1:2, the amount is 0.75%, and the foaming agent is pine oil, the amount is 5g / t. After flotation, the recovery rate of barite is 92%, and the density is 4.1g·cm -3 .

[0088] Example 27

[0089] The processing object in this embodiment is white oil-based cuttings, and the processing method refers to embodiment 17. The difference between this embodiment and embodiment 17 is that the flotation tailings are dried at 105℃ for 4h, and then mixed with bauxite and potassium feldspar in a mass ratio of 3:5:1, ball milled and sieved to obtain a mixture below 45μm, polyvinyl alcohol solution (4wt%) is added to the mixture in a mass ratio of 1:8, mixed and granulated, naturally air-dried and sieved (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain raw proppant, which is sent into an electric resistance furnace for sintering, the sintering temperature is 1200℃, the heating rate is 10℃ / min, and the temperature is kept for 3h after reaching the temperature, and the corresponding mesh proppant clinker is obtained after the furnace is stopped and cooled. The bulk density of the 20 / 40 mesh product is 1.33g·cm -3, the crushing rate at 35 MPa was 9.8%, the volume density of 30 / 50 mesh product was 1.25 g·cm -3 , the crushing rate at 35 MPa was 8.74%, the volume density of 40 / 70 mesh product was 1.36 g·cm -3 , the crushing rate at 35 MPa was 9.12%.

[0090] Example 28

[0091] The processing object in this example was white oil-based debris, and the processing method referred to Example 17, except that the flotation tailings were dried at 105℃ for 4h, and after drying, the tailings, bauxite and potassium feldspar were mixed at a mass ratio of 1.5:7:2, ball milled, sieved to obtain a mixture below 45μm, polyvinyl alcohol solution (4wt%) was added to the mixture at a mass ratio of 1:8, mixed, granulated, naturally air-dried and sieved (15 / 30 mesh, 25 / 40 mesh, 30 / 50 mesh) to obtain proppant raw material, which was sent into an electric resistance furnace for sintering, the sintering temperature was 1300℃, the heating rate was 8℃ / min, and after reaching the temperature, it was kept for 2h, and after stopping the furnace and cooling, the corresponding mesh (20 / 40 mesh, 30 / 50 mesh, 40 / 70 mesh) proppant clinker was obtained. The volume density of 20 / 40 mesh product was 1.38 g·cm -3 , the crushing rate at 35 MPa was 7.22%, the volume density of 30 / 50 mesh product was 1.35 g·cm -3 , the crushing rate at 35 MPa was 7.06%, the volume density of 40 / 70 mesh product was 1.41 g·cm -3 , the crushing rate at 35 MPa was 7.98%.

[0092] As can be seen from the above Examples 1-28, the developed oil-based debris efficient oil removal agent can effectively reduce the oil content of oil-based debris to below 1% at room temperature of 15-40℃, and Example 6 further proves that after being treated by the invented oil removal agent, the oil content can still be below 1% at low temperature of 10℃. Comparing Example 2, Example 4 and Example 5, it can be seen that temperature has a certain influence on the oil removal effect of the oil removal agent, and the oil removal effect is better in the temperature range of 35-40℃. 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 oil removal agent increases, the oil removal effect increases, but as the proportion of water decreases, the subsequent centrifugal difficulty increases. Considering the oil removal and centrifugal effect, the best use range of the oil removal agent is to compound diesel or white oil, methyl ethyl ketone, sodium silicate and water at 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 collectors can achieve a barite recovery rate of ≥90%, a density of ≥4.0 g·cm -3 , and can meet the requirements of well site recycling. It can be seen from comparative example 1, example 7, example 8, example 9, example 10, and example 11 that the targeted collector prepared by using bipyridinium salt (a) and bipyridinium salt (f) is better than the targeted collector prepared by using bipyridinium salt (b), bipyridinium salt (c), bipyridinium salt (d), and bipyridinium salt (a). It can be seen from example 12 and example 13 that the targeted collector prepared by using two or more bipyridinium salts is better than the targeted collector prepared by using a single bipyridinium salt.

Claims

1. A comprehensive utilization process for oil-based rock cuttings, characterized in that, include: Oil-based rock fragments were extracted using a countercurrent extractant, which contained the following components in the following mass ratio: target oil, methyl ethyl ketone, sodium silicate, and water in the mass ratio of 40-60:10-20:0.2-0.5:20-30. The solid phase obtained after centrifugation was extracted using a barite extraction method, with residual flotation tailings remaining. The barite extraction method uses a flotation system comprising a targeted barite collector, an inhibitor, a dispersant, and a frother. The inhibitor is a mixture of sodium phosphate, water glass, and tannic acid in a mass ratio of 1:1-2:1-3, used at a dosage of 800-1200 g / t. The frother is pine oil, used at a dosage of 5-15 g / t. The dispersant is a mixture of sodium pyrophosphate, sodium hexametaphosphate, and water glass in a mass ratio of 1-2:1-3:1, used at a dosage of 0.25-1%. The targeted barite collector comprises a bipyridinium salt and a carboxylic acid, wherein the bipyridinium salt is: ， The carboxylic acid is any one or more of the following: oxalic acid, p-hydroxybenzoic acid, trimesic acid, nicotinic acid, and 6-chloronicotinic acid; the molar ratio of the bipyridinium salt to the carboxylic acid is 1:2 to 2:

1.

2. The comprehensive utilization process of oil-based rock cuttings as described in claim 1, characterized in that, In the countercurrent extractant, the mass ratio of the target oil, methyl ethyl ketone, sodium silicate, and water is 45-55:15-20:0.2-0.3:20-25.

3. The comprehensive utilization process of oil-based rock cuttings as described in claim 1, characterized in that, The target oil to be extracted is diesel or white oil.

4. The comprehensive utilization process of oil-based rock cuttings as described in claim 1, characterized in that, The countercurrent extractant is prepared by mixing the target oil, methyl ethyl ketone, sodium silicate, and water in a specific mass ratio.

5. The comprehensive utilization process of oil-based rock cuttings as described in claim 1, characterized in that, The extraction of oil-based rock cuttings using a countercurrent extractant includes: Add oil-based rock cuttings and the countercurrent extractant at a liquid-to-solid ratio of 3-5:1, and extract at 15-40℃.

6. The comprehensive utilization process of oil-based rock cuttings as described in claim 5, characterized in that, The extraction is a 3-stage countercurrent extraction, with a single-stage extraction time of 20-35 min and a stirring speed of 350-500 r / min.

7. The comprehensive utilization process of oil-based rock cuttings as described in claim 1, characterized in that, After the extraction step, liquid-solid separation is performed to obtain a solid phase and a liquid phase, and the liquid phase is then subjected to oil-water separation.

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