EA041289B1 - CHARGE FOR MANUFACTURING MAGNESIUM-QUARTZ PROPPANT - Google Patents

Description

The invention relates to the oil and gas industry, and in particular to the production of ceramic proppants, in particular to the composition of the charge intended for the manufacture of lightweight and medium-density magnesia-quartz proppants with a bulk density of up to 1.75 g/cm ³ .

Proppants are strong spherical granules that keep hydraulic fractures from closing under high pressure and provide the required productivity of oil and gas wells by creating a conductive channel in the formation. Various organic and inorganic materials are used as proppants (proppants) - walnut shells, sand, polymer-coated sand, as well as synthetic ceramic granules. The main performance characteristics of proppants include degradability and resistance to acids. Ceramic proppants used in hydraulic fracturing are divided into high-density, medium-density, lightweight and ultra-lightweight. Given the price / quality ratio, medium-density and lightweight proppants are currently the most in demand.

Ceramic proppants presented on the Russian market are produced from aluminosilicate or magnesium silicate raw materials. The use of natural magnesium silicate raw materials, which are affordable and do not require significant processing costs, makes it possible to obtain a price-competitive product. Moreover, it is possible to manufacture both a dense proppant, completely made, for example, from serpentinite or dunite rock, and a lightweight, medium-density or lightweight proppant, made from a mixture of heat-treated magnesium silicate with quartz-feldspar sand, while the MgO content in the lightweight product is 8-30 wt.% , and the bulk density does not exceed 1.75 g/cm ³ .

It should be noted that proppants with a bulk density of more than 1.75 g/cm ³ belong to the category of dense products in the range of magnesium-containing proppants.

Traditionally, the preparation of the initial mixture for the manufacture of magnesium silicate proppants is carried out by mixing natural magnesium silicate (serpentinite, dunite, olivinite) fired at a temperature of 750-1450°C and a silica-containing component (quartz-feldspar sand and/or quartzite) and its subsequent grinding to a fraction of less than 100 microns. Next, the resulting mixture is fed to granulation. Granular raw proppant is subjected to high-temperature firing, which is performed to maximize the compaction of ceramics and optimize its chemical and phase composition.

Known compositions of the charge based on a mixture of heat-treated serpentinite with quartz feldspar sand (see RF patents No. 2446200, No. 2547033) and methods for manufacturing lightweight proppant from them. These technical solutions make it possible to obtain wedges with a bulk density of less than 1.4 g/cm ³ . The compositions of the mixture for obtaining medium-density magnesium silicate proppant based on natural magnesium silicates or their mixtures with natural quartz-feldspar sand are described in RF patents No. 2463329, No. 2588634, Eurasian patent No. 024901.

Also known charge for the manufacture of magnesium silicate proppant (see RF patent No. 2563853), containing crushed to a fraction of less than 8 μm a mixture of heat-treated serpentinite and quartz feldspar sand. As the specified sand, the mixture contains sand from the Yuzhno-Ilyinsky field of fraction less than 2 mm composition, wt.%: silicon dioxide 90.0-91.0, aluminum oxide 3.3-3.5, calcium oxide 0.9-1.0 , iron oxide 1.6-1.8, potassium oxide 1.2-1.3, sodium oxide 0.7-0.8, impurities - the rest, with the following ratio of charge components, wt.%: the specified serpentinite 61.0 -67.0 indicated sand 33.0-39.0. Magnesium silicate proppant is characterized by the fact that it is obtained from the specified charge.

Thus, the main components of the charge for large-scale production of magnesium silicate proppants are natural magnesium silicates and silica materials.

Also known from the prior art is the invention Sintered spheres, the method for their production and their use according to the patent of the Russian Federation 2750952 with a publication date of 07/06/2021, aimed at solving the problem of placing red mud waste. The purpose of this invention are sintered spheres obtained from red mud, which, as a starting material, is contained in the mixture for the manufacture of these spheres in an amount of at least 70% by weight, calculated on the dry weight. Red mud includes at least alumina, iron oxide, silicon oxide, and titanium oxide.

A preferred embodiment of the present invention are sintered spheres, which according to the claimed invention include additives from the groups containing feldspar, aluminum minerals, calcined aluminum minerals, clay minerals or silicate minerals, or mixtures thereof. The additives mentioned are additives commonly used in the manufacture of aggregates and proppants. Additives used in accordance with the claimed invention include minerals that contribute to such performance characteristics as the strength of the final product and its resistance to long-term load. Additives can be used in amounts up to 30% depending on the properties desired. In accordance with the claimed invention, the use of mineral additives affects the granulation process, which makes it possible to obtain sintered spheres that meet the requirements of the consumer, taking into account their use in various purposes.

Thus, the well-known invention is based on the use of red mud exclusively.

- 1 041289 with or without additives to obtain a wide range of products for various purposes.

Red mud is a waste from the Bayer process, an industrial process for processing bauxite to produce alumina. The sludge basically contains iron oxides in an amount of up to 60% of its mass. It also contains appreciable amounts of silica, unleached residual aluminum and titanium dioxide. Therefore, the spheres obtained in accordance with the known invention do not belong to the category of magnesia-quartz products. In addition, the use of red mud containing a high (up to 60 wt.%) amount of iron oxides in its composition leads to a sharp increase in the amount of the liquid phase in the proppant granules during sintering firing and the formation of a significant amount of cakes.

Recently, there has been a trend towards a gradual decrease in prices for natural hydrocarbons in the commodity markets. Consequently, it becomes quite obvious that it is necessary to reduce the cost of their production, including by reducing the cost of proppants used in the hydraulic fracturing operation. In this regard, specialists working in the field of production of magnesia-quartz proppants are studying the possibility of using non-traditional, cheap raw materials, for example, various technogenic materials, as part of the initial charge.

The technical problem to be solved by the claimed invention is the expansion of the raw material base for the production of magnesia-quartz proppants with a bulk density of up to 1.75 g/ ^cm the main operational characteristics of the corresponding requirements of GOST R 54571-2011 Magnesia-quartz proppants.

This problem is solved by the fact that the mixture for the manufacture of magnesia-quartz proppant contains 8-30 wt.% MgO in its composition and is a mixture of crushed magnesium silicate crushed stone and natural silica sand crushed to a fraction of less than 100 microns, moreover, this mixture additionally contains 1- 50 wt.% iron ore slurry of the Kachkanar Mining and Processing Plant. As magnesium silicate crushed stone, antigorite and/or antigorite-lizardite crushed stones are used. As antigorite magnesium silicate crushed stones, crushed stones of the Gornoshchitskoye and Shabrovsky deposits (RF, Sverdlovsk region) are used, and crushed stone of the Bazhenovskoye deposit (RF, Sverdlovsk region) is used as antigorite-lizardite magnesium silicate crushed stone. In addition, magnesia-quartz proppant is characterized by the fact that it is made from the specified charge.

Iron ore sludge from the Kachkanar Mining and Processing Plant (Russian Federation, Sverdlovsk region) is a by-product of wet magnetic separation during the enrichment of iron ore. Sludge is a low-iron fine-grained material, fractions less than 5 mm and is used in the production of concrete, ceramic tiles, bricks and is used in road and construction work.

Thus, the iron ore sludge of the Kachkanar Mining and Processing Plant is a large-tonnage and accessible technogenic raw material. Therefore, its involvement in the large-scale production of ceramic proppants is of great practical interest. It should be emphasized that the knowledge of the use of iron ore slurry from the Kachkanar Mining and Processing Plant as a charge component for the production of ceramic proppants for oil wells (proppants) does not follow from the prior art, which ensures that the claimed invention meets the conditions of novelty and inventive step.

The study of iron ore slurry from the Kachkanar Mining and Processing Plant shows that it is a low-magnesia and low-iron material containing calcium and aluminum oxides, as well as silicon dioxide. The sludge has the following average chemical composition, wt.%: MgO - 15, CaO - 24, Al ₂ O ₃ - 7, SiO ₂ - 42, Fe ₂ O ₃ - 9, impurities - the rest. The fluctuation of the content of the main components is ± 10% of the values of the average indicators. Weight loss on ignition up to 0.5 wt.%. Low weight loss during ignition allows you to enter the sludge into the mixture without pre-calcination.

Also, the authors experimentally found that the sludge has a low melting point - 1150-1200°C and its introduction into the mixture to obtain proppant allows to lower the firing temperature of raw proppant granules. In addition, during the firing of raw proppant obtained from a charge that combines a silica component, magnesium silicate crushed stone and low-melting sludge from the Kachkanar Mining and Processing Plant, an increased content of the liquid phase is formed, which contributes to the compaction and hardening of ceramics during firing. After the calcined proppant cools, said liquid phase transforms into a glass phase with reduced solubility in acids. The use of the proposed sludge in the charge in an amount of less than 1 wt.% impractical, since it clearly does not contribute to the solution of the technical problem - the expansion of the raw material base for the production of magnesia-quartz proppant. An increase in the sludge content in the charge above 50 wt.% leads to a sharp increase in the amount of liquid phase in the granules during sintering firing, which leads to the formation of a significant amount of sinter.

The choice of antigorite and/or antigorite as a magnesium silicate component of the charge

- 2 041289 lizardite crushed stones due to their higher grinding capacity in comparison with dunite, olivinite crushed stones. In addition, these crushed stones have low (up to 10 wt.%) losses during ignition, which allows them to be used both without pre-fired and in pre-fired form. It should be emphasized that the claimed magnesium silicate gravel does not contain harmful fibrous impurities (asbestos), which favorably affects the environmental situation in production units. Within the framework of the proposed technical solution, antigorite crushed stones of the Gornoshchitskoye and Shabrovsky deposits were used with an antigorite content of 87-98 wt.%, as well as antigorite-lizardite crushed stone of the Bazhenov deposit with a content of lizardite up to 20 wt.% and antigorite above 75 wt.% MgO content in these crushed stones fluctuates within 36-46 wt.%. It should be noted that antigorite and lizardite belong to the same group of minerals. In this regard, their ratio in crushed stone does not affect the solution of the technical problem. However, the claimed magnesium silicate rubble and iron ore sludge have some fluctuations in chemical composition. Therefore, it is advisable to control the ratio of the components of the mixture by the content of magnesium oxide (MgO) in it. In this case, the calculation of the charge composition is not difficult for a specialist in the field of chemical technology of ceramic and refractory materials.

The conducted studies have established that the quantitative and qualitative composition of impurities contained in the claimed components of the charge do not affect the possibility of obtaining a proppant that, according to the main operational characteristics, meets the requirements of GOST R 54571-2011 Magnesia-quartz proppants. It has also been experimentally established that with an increase in the MgO content in the charge of more than 30 wt.%, the bulk density of the proppant exceeds 1.75 g/cm ³ , while the requirements of GOST R 54571-2011 apply to proppant with a bulk density of less than 1.75 g /cm ³ . When the content of MgO in the raw mixture is less than 8 wt.%, the proppant obtained from it during firing has a bulk density of less than 1.3 g/ ^cm In addition, according to GOST R 54571-2011, the MgO content in the proppant should not be less than 8 wt.%.

Examples of the invention.

Example 1

kg (50 wt.%) dried at 150 ° sludge of the Kachkanar mining and processing plant with an MgO content of approximately 15 wt.%, 4 kg fired at 1130 ° C antigorite crushed stone of the Gornoshchitskoye deposit with an MgO content of approximately 40 wt.% and 1 kg dried at 150° natural quartz-feldspar sand was co-milled in a laboratory mill to a fraction of less than 100 microns to obtain a mixture containing approximately 23.5 wt.% MgO. Proppant was produced from the mixture obtained in a laboratory granulator - crude, which was fired at a temperature of 1200°C.

The 16/20 mesh calcined proppant was tested for compliance with the main performance characteristics of the requirements of GOST R 54571-2011:

destructibility, at a pressure of 68.9 MPa, wt.% - no more than 25.0;

solubility in a mixture of acids, wt.% - no more than 10.0.

In a similar way, a charge was prepared with different contents of the sludge from the Kachkanar mining and processing plant, burnt antigorite crushed stone and quartz-feldspar sand with a charge content of 8-30 wt.% MgO. The measurement results are given in table. 1.

Example 2

kg (50 wt.%) dried at 150 ° sludge of the Kachkanar mining and processing plant with an MgO content of approximately 15 wt.%, 4 kg fired at 1150 ° C antigorite-lizardite crushed stone of the Bazhenov deposit with an MgO content of approximately 40 wt.% and 1 kg dried at 150° natural quartz-feldspar sand was subjected to joint grinding in a laboratory mill to a fraction of less than 100 microns to obtain a charge containing approximately 23.5 wt.% MgO. Raw proppant was produced from the mixture obtained in a laboratory granulator, which was fired at a temperature of 1170°C.

The 16/20 mesh calcined proppant was tested for compliance with the main performance characteristics of the requirements of GOST R 54571-2011:

destructibility, at a pressure of 68.9 MPa, wt.% - no more than 25.0;

solubility in a mixture of acids, wt.% - no more than 10.0.

Similarly, a charge was prepared with different contents of the sludge of the Kachkanar mining and processing plant, burnt antigorite-lizardite crushed stone and quartz-feldspar sand with a charge content of 8-30 wt.% MgO. The measurement results are given in table. 2.

Example 3

0.1 kg (1 wt.%) dried at 150 ° sludge of the Kachkanar mining and processing plant with an MgO content of approximately 15 wt.%, 2.2 kg of unbaked antigorite crushed stone of the Shabrovsky deposit with an MgO content of approximately 36 wt.% and 7.7 kg of natural quartz-feldspar sand dried at 150° was subjected to joint grinding in a laboratory mill to a fraction of less than 100 μm to obtain a charge containing approximately 8 wt.% MgO. From the mixture obtained

- 3 041289 laboratory granulator produced raw proppant, which was fired at a temperature of 1250°C.

The 16/20 mesh calcined proppant was tested for compliance with the main performance characteristics of the requirements of GOST R 54571-2011:

destructibility, at a pressure of 68.9 MPa, wt.% - no more than 25.0;

solubility in a mixture of acids, wt.% - no more than 10.0.

Similarly, a charge was prepared with different contents of the sludge of the Kachkanar mining and processing plant, unburned antigorite crushed stone and quartz-feldspar sand with a charge content of 8-30 wt.% MgO. The measurement results are given in table. 3.

Example 4

2.0 kg (20 wt.%) dried at 150 ° sludge of the Kachkanar mining and processing plant with an MgO content of approximately 15 wt.%, 3.5 kg of antigorite-lizardite crushed stone of the Bazhenov deposit fired at 1150 ° C with an MgO content of approximately 40 wt. .%, 3.5 kg of unbaked antigorite crushed stone of the Shabrovsky deposit with an MgO content of approximately 36 wt.% and 1 kg of natural quartz-feldspar sand dried at 150 ° were subjected to joint grinding in a laboratory mill to a fraction of less than 100 μm to obtain a charge containing approximately 30 wt. % MgO. Raw proppant was produced from the mixture obtained in a laboratory granulator, which was fired at a temperature of 1200°C.

The 16/20 mesh calcined proppant was tested for compliance with the main performance characteristics of the requirements of GOST R 54571-2011:

destructibility, at a pressure of 68.9 MPa, wt.% - no more than 25.0;

solubility in a mixture of acids, wt.% - no more than 10.0.

In a similar way, a charge was prepared with different contents of sludge from the Kachkanar mining and processing plant, a mixture of burnt antigorite-lizardite and unburned antigorite crushed stone and quartz feldspar sand with a charge content of 8-30 wt.% MgO. The measurement results are given in table. 4.

An analysis of these tables shows that the use of the claimed mixture for the manufacture of magnesia-quartz proppant (examples 1-6, tables 1-4) expands the raw material base for the production of proppant and allows you to obtain a product that meets the requirements of GOST R 54571-2011 according to the main performance characteristics. At the same time, the problem of processing iron ore sludge from the Kachkanar Mining and Processing Plant is being solved. The authors confirm that the production of magnesia-quartz proppant that meets the requirements of GOST R 54571-2011 from a charge containing 8-30 wt.% MgO and containing 1-50 wt.% sludge from the Kachkanar mining and processing plant is possible using magnesium silicate crushed dunite, olivinite and other magnesium silicate rocks, providing the claimed content of magnesium oxide in the mixture.

Table 1

No. p / p The content of Kachkanar iron ore sludge, wt.% MgO content, wt.% Destructibility at a load of 68.9 MPa, wt.% Solubility in acids, wt.% Bulk density, g / cm ³ 1. 1.0 8.0 24.1 5.3 1.3 2. 1.0 30.0 19.1 6.4 1.69 3. 50.0 8.0 24.5 5.7 1.41 4. 50.0 30.0 23.1 6.5 1.58 5. 5.0 18.0 19.6 6.2 1.47 6. 25.0 30.0 19.4 7.2 1.63 7. 50.0 23.5 19.2 6.3 1.56 8. 53.0 22.1 During the roasting of the raw proppant, cakes are formed 6.3

table 2

No. p / p The content of Kachkanar iron ore sludge, wt.% MgO content, wt.% Destructibility at a load of 68.9 MPa, wt.% Solubility in acids, wt.% Bulk density, g / cm ³ 1. 1.0 8.0 24.7 5.1 1.32 2. 1.0 30.0 21.4 6.9 1.7 3. 50.0 8.0 24.5 5.3 1.39 4. 50.0 30.0 22.3 6.8 1.57 5. 5.0 18.0 20.5 6.7 1.49 6. 25.0 30.0 22.7 7.6 1.65 7. 50.0 23.5 23.2 6.7 1.58 8. 53.0 22.1 During the roasting of the raw proppant, cakes are formed 6.9

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Claims (5)

Table 3 No. Content of Kachkanar iron ore slurry, wt.% MgO content, wt.% Destructibility at a load of 68.9 MPa, wt.% Solubility in acids, wt.% Bulk density, g/cm3 1. Charge for the manufacture of magnesia-quartz proppant, containing in its composition 8-30 wt.% MgO and representing a mixture of crushed magnesium silicate crushed stone and natural silica sand, crushed to a fraction of less than 100 microns, characterized in that it additionally contains 1-50 wt.% iron ore sludge from the Kachkanar Mining and Processing Plant. 1. 1.0 8.0 21.1 5.0 1.33 1. 1.0 8.0 22.5 5.5 1.3 2. The charge according to claim 1, characterized in that antigorite and/or antigorite-lizardite crushed stones are used as magnesium silicate crushed stone. 2. 1.0 30.0 18.6 6.7 1.73 2. 1, oh 30.0 18.1 6.8 1.69 3. The charge according to claim 2, characterized in that crushed stones of the Gornoshchitskoye and Shabrovsky deposits are used as antigorite magnesium silicate crushed stones. 3. 50.0 8.0 24.7 5.1 1.42 3. 50.0 8.0 23.5 5.6 1.44 4. The mixture according to claim 2, characterized in that crushed stone of the Bazhenov deposit is used as antigorite-lizardite magnesium silicate crushed stone. 4. 50.0 30.0 21.1 7.5 1.56 5. 5.0 18.0 17.2 6.0 1.53 6. 20.0 30.0 22.4 7.3 1.65 7. 50.0 23.5 18.3 6.8 1.56 8. 53.0 22.1 During the roasting of the raw proppant, cakes are formed 6.8 CLAIM 4. 50.0 30.0 20.2 6.8 1.52 5. 5.0 18.0 18.1 6.0 1.5 6. 25.0 30.0 20.4 7.9 1.64 7. 50.0 23.5 17.8 6.9 1.51 8. 53.0 22.1 During the roasting of the raw proppant, cakes are formed 6.9 Table 4 No. Content of Kachkanar iron ore slurry, wt.% MgO content, wt.% Destructibility at a load of 68.9 MPa, wt.% Solubility in acids, wt.% Bulk density, g / cm ³ 5. Proppant, characterized in that it is made from the mixture according to claims 1-4. Eurasian Patent Organization, EAPO Russia, 109012, Moscow, Maly Cherkassky per., 2