Petroleum fracturing high-strength and high-density ceramsite proppant and application

Abstract

The invention relates to a high-strength and high-density ceramsite proppant for petroleum fracturing and application, and the proppant is prepared from the following raw materials in parts by weight: 30-50 parts of kaolin, 10-16 parts of montmorillonite, 8-12 parts of basalt, 6-8 parts of coal gangue, 6-8 parts of diatomite, 4-6 parts of vesuvianite, 10-20 parts of potassium phosphate solution and 2-5 parts of aluminum powder. According to the proppant provided by the invention, the kaolin, the montmorillonite, the basalt, the coal gangue, the diatomite and the pelelith are matched, so that the strength of the proppant is ensured, the strength of the proppant is obviously improved to a certain extent due to the addition of the pelelith, the breakage rate of the proppant is reduced, and meanwhile, the high density of the proppant is also ensured.

Description

Technical Field

[0001] The invention relates to the technical field of oil extraction, and in particular to a high-strength and high-density ceramsite proppant for oil fracturing and an application thereof. Background Art

[0002] During the oil production process, hydraulic fractures will be generated. Under the condition that the reservoir characteristics and fracture geometry are the same, the production increase effect of the fracturing well and its production dynamics mainly depend on the conductivity of the hydraulic fractures, that is, the ability of the hydraulic fractures to conduct or transport reservoir fluids. The role of ceramsite proppants is to fill the hydraulic fractures generated by fracturing, so that the hydraulic fractures will not close again and form a flow channel with high conductivity. Therefore, the type of proppant, its physical properties, its distribution in the fractures, and the closing pressure of the fractures are the main factors controlling the fracture conductivity. Therefore, the properties of ceramsite proppants have a significant impact on oil fracturing production.

[0003] With the continuous increase in the depth of oil and gas wells, new requirements are put forward for the performance of ceramsite proppants. However, the breakage rate of existing ceramsite proppants is 8-10% at 100MPa, the anti-breakage ability is not strong, and the durability to acid and alkali is not good, which affects the use effect of ceramsite proppants and further affects oil extraction. Summary of the invention

[0004] The present invention provides a high-strength and high-density ceramsite proppant for petroleum fracturing and its application to solve the above problems.

[0005] The technical solution adopted by the present invention is: a high-strength and high-density ceramsite proppant for oil fracturing, which comprises the following raw materials by weight: 30-50 parts of kaolin, 10-16 parts of montmorillonite, 8-12 parts of basalt, 6-8 parts of coal gangue, 6-8 parts of diatomaceous earth, and 4-6 parts of volcanic rock.

[0006] Preferably, the proppant further comprises the following components by weight: 10-20 parts of potassium phosphate solution and 2-5 parts of aluminum powder.

[0007] Preferably, the proppant further comprises the following components by weight: 6-15 parts of water glass, 10-30 parts of phenolic resin, and 10-20 parts of epoxy resin.

[0008] Preferably, the method for preparing the proppant comprises the following steps:

[0009] S1: According to the weight ratio, kaolin, basalt, diatomaceous earth, and volcanic rock are weighed, and at the same time, montmorillonite of 3 / 4 of the total weight and coal gangue of 1 / 2 of the total weight are weighed, and mixed to obtain a mixed raw material;

[0010] S2: Weigh aluminum powder, take the remaining montmorillonite and coal gangue, mix them and add them into a ball mill for ball milling to obtain powder, add the obtained powder into potassium phosphate solution, stir and mix for 0.5-1h to obtain a preformulation;

[0011] S3: adding water to the mixed raw materials, placing them in a ball mill for stirring and wet grinding, adding the preformulation several times during the wet grinding process, and ball milling to obtain a slurry;

[0012] S4: drying the slurry obtained in step S3, granulating it, and obtaining pellets after screening and drying;

[0013] S5: The pellets obtained in step S4 are placed in a high-temperature kiln for calcination to obtain ceramsite.

[0014] Preferably, the method for preparing the proppant further comprises: coating water glass on the ceramsite obtained in step S5 by a spraying device to obtain coated pellets, then, mixing phenolic resin and epoxy resin evenly and coating them on the surface of the coated pellets by a spraying device, and drying and baking again after the spraying is completed.

[0015] Preferably, the ball milling time in step S3 is 4-6 hours, the ball-to-material ratio is 10:1, the rotation speed is 300-700 r / min, and the preformulation is added to the ball mill in equal amounts over 3-5 times.

[0016] Preferably, the calcination temperature is 800-1200° C. and the calcination time is 2-3 h.

[0017] Preferably, the potassium phosphate solution is an aqueous solution of potassium phosphate with a concentration of 0.2 mol / L.

[0018] Compared with the prior art, the present invention has the following advantages: (1) The present invention provides a proppant, which is prepared by combining kaolin, montmorillonite, basalt, coal gangue, diatomaceous earth and volcanic rock to ensure the strength of the proppant, wherein the addition of volcanic rock significantly improves the strength of the proppant to a certain extent, reduces its breakage rate, and also ensures the high density of the proppant; (2) The addition of aluminum powder further improves the compressive strength of the proppant; (3) The addition of montmorillonite as a raw material ensures the strength of the proppant, and at the same time, montmorillonite forms a colloid after contacting water and has a certain bonding property, thereby improving the properties of the various The addition of potassium phosphate solution facilitates the formation of composite materials through reaction, reduces cohesive force, and increases the bonding force of the bonding interface between particles, thereby increasing the bonding strength of the proppant, thereby improving the strength of the proppant; (5) The addition of water glass facilitates further improving the bonding strength between different particles inside the proppant, and at the same time, it also facilitates the bonding between phenolic resin and epoxy resin and the pellets to be more stable. The coating of phenolic resin and epoxy resin improves the acid and alkali corrosion resistance of the proppant to a certain extent, and improves the strength of the proppant to a certain extent. DETAILED DESCRIPTION

[0019] In order to better illustrate the present invention, it is further described in conjunction with examples.

[0020] A high-strength and high-density ceramsite proppant for petroleum fracturing. The proppant comprises the following raw materials in parts by weight: 30-50 parts of kaolin, 10-16 parts of montmorillonite, 8-12 parts of basalt, 6-8 parts of coal gangue, 6-8 parts of diatomaceous earth, 4-6 parts of volcanic rock, 10-20 parts of potassium phosphate aqueous solution, 2-5 parts of aluminum powder, 6-15 parts of water glass, 10-30 parts of phenolic resin and 10-20 parts of epoxy resin, wherein the concentration of the potassium phosphate aqueous solution is 0.2 mol / L.

[0021] The preparation method of the proppant comprises the following steps:

[0022] S1: According to the weight ratio, kaolin, basalt, diatomaceous earth, and volcanic rock are weighed, and at the same time, montmorillonite of 3 / 4 of the total weight and coal gangue of 1 / 2 of the total weight are weighed, and mixed to obtain a mixed raw material;

[0023] S2: Weigh aluminum powder, take the remaining montmorillonite and coal gangue, mix them and add them into a ball mill for ball milling. The ball milling time is 1-2 hours, the ball-to-material ratio is 8:1, and the rotation speed is 500r / min to obtain powder. The obtained powder is added into potassium phosphate solution and stirred for 0.5-1h to obtain a preformulation;

[0024] S3: adding water to the mixed raw materials, and placing them in a ball mill for stirring and wet grinding. During the wet grinding process, the preformulation is added in equal amounts in 3-5 times, and the slurry is obtained by ball milling. The ball milling time is 4-6 hours, the ball-to-material ratio is 10:1, and the rotation speed is 300-700r / min;

[0025] S4: drying the slurry obtained in step S3, granulating it, and obtaining pellets after screening and drying;

[0026] S5: placing the pellets obtained in step S4 in a high-temperature kiln for calcination at a temperature of 800-1200° C. for 2-3 hours to obtain ceramsite;

[0027] S6: coating water glass on the ceramsite obtained in step S5 by spraying equipment to obtain coated pellets, then mixing phenolic resin and epoxy resin evenly and coating them on the surface of the coated pellets by spraying equipment, and drying and baking again after spraying to obtain a proppant.

[0028] Example 1

[0029] A high-strength and high-density ceramsite proppant for petroleum fracturing. The proppant comprises the following raw materials, measured by weight: 30 parts of kaolin, 16 parts of montmorillonite, 8 parts of basalt, 8 parts of coal gangue, 6 parts of diatomaceous earth, 6 parts of volcanic rock, 10 parts of potassium phosphate aqueous solution, 5 parts of aluminum powder, 6 parts of water glass, 30 parts of phenolic resin, and 10 parts of epoxy resin, wherein the concentration of the potassium phosphate aqueous solution is 0.2 mol / L.

[0030] The preparation method of the proppant comprises the following steps:

[0031] S1: According to the weight ratio, kaolin, basalt, diatomaceous earth, and volcanic rock are weighed, and at the same time, 12 parts of montmorillonite and 4 parts of coal gangue are weighed, and mixed to obtain a mixed raw material;

[0032] S2: Weigh aluminum powder, 4 parts of montmorillonite and 4 parts of coal gangue, mix them and add them into a ball mill for ball milling. The ball milling time is 2 hours, the ball-to-material ratio is 8:1, and the rotation speed is 500 r / min to obtain a powder. The obtained powder is added into a potassium phosphate solution and stirred for 1 hour to obtain a preformulation.

[0033] S3: adding water to the mixed raw materials, and placing them in a ball mill for stirring and wet grinding. During the wet grinding process, the preformulation was added in equal amounts in 5 times, and the slurry was obtained by ball milling. The ball milling time was 6 hours, the ball-to-material ratio was 10:1, and the rotation speed was 700 r / min;

[0034] S4: drying the slurry obtained in step S3, granulating it, and obtaining pellets after screening and drying;

[0035] S5: placing the pellets obtained in step S4 in a high-temperature kiln for calcination at a temperature of 1200° C. for 2 h to obtain ceramsite.

[0036] S6: coating water glass on the ceramsite obtained in step S5 by spraying equipment to obtain coated pellets, then mixing phenolic resin and epoxy resin evenly and coating them on the surface of the coated pellets by spraying equipment, and drying and baking again after spraying to obtain proppant; after testing, the bulk density of the proppant is 1.95 g / cm 3 .

[0037] Example 2

[0038] A high-strength and high-density ceramsite proppant for petroleum fracturing. The proppant comprises the following raw materials, measured by weight: 50 parts of kaolin, 10 parts of montmorillonite, 12 parts of basalt, 6 parts of coal gangue, 8 parts of diatomaceous earth, 4 parts of volcanic rock, 20 parts of potassium phosphate aqueous solution, 2 parts of aluminum powder, 15 parts of water glass, 10 parts of phenolic resin, and 20 parts of epoxy resin, wherein the concentration of the potassium phosphate aqueous solution is 0.2 mol / L.

[0039] The preparation method of the proppant comprises the following steps:

[0040] S1: According to the weight ratio, kaolin, basalt, diatomaceous earth, and volcanic rock are weighed, and at the same time, 7.5 parts of montmorillonite and 3 parts of coal gangue are weighed, and mixed to obtain a mixed raw material;

[0041] S2: Weigh aluminum powder, take the remaining montmorillonite and coal gangue, mix them and add them into a ball mill for ball milling. The ball milling time is 1 hour, the ball-to-material ratio is 8:1, and the rotation speed is 500 r / min to obtain a powder. The obtained powder is added into the potassium phosphate solution and stirred for 40 minutes to obtain a preformulation;

[0042] S3: Add water to the mixed raw materials, and place them in a ball mill for stirring and wet grinding. During the wet grinding process, the preformulation is added in equal amounts three times, and the slurry is obtained by ball milling. The ball milling time is 4 hours, the ball-to-material ratio is 10:1, and the rotation speed is 300r / min;

[0043] S4: drying the slurry obtained in step S3, granulating it, and obtaining pellets after screening and drying;

[0044] S5: placing the pellets obtained in step S4 in a high-temperature kiln for calcining at a temperature of 1000° C. for 2 hours to obtain ceramsite;

[0045] S6: coating water glass on the ceramsite obtained in step S5 by spraying equipment to obtain coated pellets, then mixing phenolic resin and epoxy resin evenly and coating them on the surface of the coated pellets by spraying equipment, and drying and baking again after spraying to obtain proppant; after testing, the bulk density of the proppant is 1.97 g / cm 3 .

[0046] Example 3

[0047] A high-strength and high-density ceramsite proppant for petroleum fracturing. The proppant comprises the following raw materials in parts by weight: 40 parts of kaolin, 12 parts of montmorillonite, 10 parts of basalt, 7 parts of coal gangue, 7 parts of diatomaceous earth, 5 parts of volcanic rock, 15 parts of potassium phosphate aqueous solution, 4 parts of aluminum powder, 10 parts of water glass, 20 parts of phenolic resin, and 15 parts of epoxy resin, wherein the concentration of the potassium phosphate aqueous solution is 0.2 mol / L.

[0048] The preparation method of the proppant comprises the following steps:

[0049] S1: According to the weight ratio, kaolin, basalt, diatomaceous earth, and volcanic rock are weighed, and at the same time, 9 parts of montmorillonite and 3.5 parts of coal gangue are weighed, and mixed to obtain a mixed raw material;

[0050] S2: Weigh aluminum powder, take the remaining montmorillonite and coal gangue, mix them and add them into a ball mill for ball milling. The ball milling time is 1.5 hours, the ball-to-material ratio is 8:1, and the rotation speed is 500 r / min to obtain a powder. The obtained powder is added into the potassium phosphate solution and stirred for 1 hour to obtain a preformulation;

[0051] S3: adding water to the mixed raw materials, and placing them in a ball mill for stirring and wet grinding. During the wet grinding process, the preformulation was added in equal amounts in 4 times, and the slurry was obtained by ball milling. The ball milling time was 5 hours, the ball-to-material ratio was 10:1, and the rotation speed was 600 r / min;

[0052] S4: drying the slurry obtained in step S3, granulating it, and obtaining pellets after screening and drying;

[0053] S5: placing the pellets obtained in step S4 in a high-temperature kiln for calcining at a temperature of 1100° C. for 3 hours to obtain ceramsite;

[0054] S6: Spray water glass onto the ceramsite obtained in step S5 to obtain coated pellets. Then, mix phenolic resin and epoxy resin evenly and spray them onto the surface of the coated pellets. After spraying, dry and bake the pellets to obtain proppant. The bulk density of the proppant is 1.98 g / cm 3 .

[0055] Comparative Example 1

[0056] Compared with Example 3, the proppant in Comparative Example 1 does not include potassium phosphate aqueous solution, and is replaced by the same weight of deionized water.

[0057] Comparative Example 2

[0058] Compared with Example 3, the proppant in Comparative Example 2 does not contain water glass.

[0059] Comparative Example 3

[0060] A high-strength and high-density ceramsite proppant for oil fracturing comprises the following raw materials by weight: 40 parts of kaolin, 9 parts of montmorillonite, 10 parts of basalt, 3.5 parts of coal gangue, 7 parts of diatomaceous earth, 5 parts of volcanic rock, 20 parts of phenolic resin and 15 parts of epoxy resin.

[0061] The preparation method of the proppant comprises the following steps:

[0062] S1: weigh kaolin, basalt, diatomaceous earth, volcanic rock, montmorillonite, and coal gangue according to weight proportion, and mix them to obtain a mixed raw material;

[0063] S2: adding water to the mixed raw materials, and placing the mixed raw materials in a ball mill for stirring and wet grinding. During the wet grinding process, the same volume of deionized water as in Example 3 was added in equal amounts four times, and the slurry was obtained by ball milling. The ball milling time was 5 h, the ball-to-material ratio was 10:1, and the rotation speed was 600 r / min;

[0064] S3: drying the slurry obtained in step S2, granulating it, and obtaining pellets after screening and drying;

[0065] S4: placing the autumn deer obtained in step S3 in a high-temperature kiln for calcining at a temperature of 1100° C. for 3 hours to obtain ceramsite;

[0066] S5: coating water glass on the ceramsite obtained in step S4 by spraying equipment to obtain coated pellets, then mixing phenolic resin and epoxy resin evenly and coating them on the surface of the coated pellets by spraying equipment, and drying and baking again after spraying to obtain a proppant;

[0067] Comparative Example 4

[0068] A high-strength and high-density ceramsite proppant for oil fracturing comprises the following raw materials by weight: 40 parts of kaolin, 9 parts of montmorillonite, 10 parts of basalt, 3.5 parts of coal gangue, 7 parts of diatomaceous earth, 5 parts of volcanic rock, 20 parts of phenolic resin and 15 parts of epoxy resin.

[0069] The preparation method of the proppant comprises the following steps:

[0070] S1: weigh kaolin, basalt, diatomaceous earth, volcanic rock, montmorillonite, and coal gangue according to weight proportion, and mix them to obtain a mixed raw material;

[0071] S2: adding water to the mixed raw materials, and placing the mixed raw materials in a ball mill for stirring and wet grinding. During the wet grinding process, the same volume of deionized water as in Example 3 was added in equal amounts four times, and the slurry was obtained by ball milling. The ball milling time was 5 h, the ball-to-material ratio was 10:1, and the rotation speed was 600 r / min;

[0072] S3: drying the slurry obtained in step S2, granulating it, and obtaining pellets after screening and drying;

[0073] S4: placing the pellets obtained in step S3 in a high-temperature kiln for calcination at a temperature of 1100° C. for 3 hours to obtain ceramsite.

[0074] Comparative Example 5

[0075] Compared with Example 3, no volcanic rock was added in Comparative Example 5.

[0076] Performance Testing

[0077] The compressive strength of ceramsite proppant was tested using the SY / T5108 method. The test results are shown in Table 1:

[0078] Crushing rate (closing pressure 103MPa)% Example 1 4.84 Example 2 4.31 Example 3 3.78 Comparative Example 1 5.31 Comparative Example 2 4.97 Comparative Example 3 7.24 Comparative Example 4 10.51 Comparative Example 5 5.18

[0079] The above are only preferred embodiments of the present invention. It should be pointed out that those skilled in the art may make several changes and improvements without departing from the overall concept of the present invention, and these should also be regarded as the protection scope of the present invention.

Claims

1. A high-strength, high-density ceramsite proppant for oil fracturing, characterized by: The proppant comprises the following raw materials by weight: 30-50 parts of kaolin, 10-16 parts of montmorillonite, 8-12 parts of basalt, 6-8 parts of coal gangue, 6-8 parts of diatomaceous earth and 4-6 parts of volcanic rock.

2. The high-strength and high-density ceramsite proppant for oil fracturing according to claim 1, characterized in that: The proppant further comprises the following components by weight: 10-20 parts of potassium phosphate solution and 2-5 parts of aluminum powder.

3. The high-strength and high-density ceramsite proppant for oil fracturing according to claim 1, characterized in that: The proppant further comprises the following components by weight: 6-15 parts of water glass, 10-30 parts of phenolic resin and 10-20 parts of epoxy resin.

4. The high-strength and high-density ceramsite proppant for oil fracturing according to claim 1, characterized in that: The preparation method of the proppant comprises the following steps: S1: According to the weight ratio, kaolin, basalt, diatomaceous earth, and volcanic rock are weighed, and at the same time, montmorillonite of 3 / 4 of the total weight and coal gangue of 1 / 2 of the total weight are weighed, and mixed to obtain a mixed raw material; S2: Weigh aluminum powder, take the remaining montmorillonite and coal gangue, mix them and add them into a ball mill for ball milling to obtain powder, add the obtained powder into potassium phosphate solution, stir and mix for 0.5-1 h to obtain a preformulation; S3: adding water to the mixed raw materials, placing them in a ball mill for stirring and wet grinding, adding the preformulation several times during the wet grinding process, and ball milling to obtain a slurry; S4: drying the slurry obtained in step S3, granulating it, and obtaining pellets after screening and drying; S5: placing the pellets obtained in step S4 in a high-temperature kiln for calcining to obtain ceramsite.

5. The high-strength and high-density ceramsite proppant for oil fracturing according to claim 4, characterized in that: The method for preparing the proppant also includes: coating water glass on the ceramsite prepared in step S5 by a spraying device to obtain coated pellets, then, mixing phenolic resin and epoxy resin evenly and coating them on the surface of the coated pellets by a spraying device, and drying and baking again after the spraying is completed.

6. The high-strength and high-density ceramsite proppant for oil fracturing according to claim 4, characterized in that: In step S3, the ball milling time is 4-6 h, the ball-to-material ratio is 10:1, the rotation speed is 300-700 r / min, and the pre-preparation is added to the ball mill in equal amounts over 3-5 times.

7. The high-strength and high-density ceramsite proppant for oil fracturing according to claim 1, characterized in that: The calcination temperature is 800-1200 °C and the calcination time is 2-3 h.

8. The high-strength and high-density ceramsite proppant for oil fracturing according to claim 7, characterized in that: The potassium phosphate solution is an aqueous solution of potassium phosphate with a concentration of 0.2 mol / L.