Lightweight plugging material

FIELD: oil and gas industry.

SUBSTANCE: lightweight plugging material contains cement PTsT-I-100, lightweight - expanded vermiculite, technical salt, chemical agent Crep, at the following ratio in wt %: cement PTsT-I-100 - 84.75; vermiculite - 9.42; Crep - 1.13; NaCl - 4.7. During the cement slurry preparation - expanded vermiculite, technical salt.

EFFECT: exclusion of the hydraulic fracture during wells cementation due to improved parameters of the packing cement, increased strength of cement stone at low and moderate temperatures at early stage of solidification upon simultaneous density reduction of the cement slurry.

1 tbl

 

The invention relates to cement slurries used for cementing casing in oil, gas and gas condensate wells, complicated by the presence of reservoirs with low pressure hydraulic fracturing.

Known light-weight backfill material comprising Portland cement, expanded vermiculite sand, aluminosilicate microspheres, granulated sodium chloride. (Patent RU 2243358 CI EV 33/138, 2003). The technical result of the invention is to provide a lightweight cement slurry with high stability and low permeability.

Lightweight backfill material comprising Portland cement, expanded vermiculite, aluminum silicate microspheres further comprises a granulated calcium chloride as a stabilizing additive in the following content of components, wt. %:

Portland85 - 89,5
Exfoliated vermiculite2-5
Aluminosilicate microspheres2-5
Granulated calcium chlorideelse

Granulated calcium chloride is produced according to TU 609-4711-81 and consists of granules b�logo color with a content of active substance of at least 90%.

Known backfill material although it has good stability and low filtering, but its disadvantage is the low strength of cement stone in bending.

The closest in composition and purpose is light-weight backfill material comprising Portland cement, silica-alumina microspheres, and further comprises exfoliated vermiculite, patent RU No. 2187621, IPC EV 33/138. Development of lightweight backfill material with reduced water separation forms the cement stone, which are characterized by high strength of adhesion to the casing. Lightweight backfill material includes Portland cement, expanded vermiculite and inorganic aluminosilicate microspheres at the following content of components, wt. %:

Portland90-98
Exfoliated vermiculite1-5
Aluminosilicate microsphereselse

Aluminosilicate microspheres is a product separation evils CHP, is a lightweight loose gray powder composed of individual hollow spherical particles. Durability of membranes for destruction under hydrostatic compression up to 30 MPa.

And�known backfill material although it has a low filtering, however, its disadvantage is the low strength of cement stone with weight higher offer.

Object of the invention is improving the quality of cementing by increasing the strength of cement.

Lightweight backfill material includes Portland cement, expanded vermiculite, string sifted through sieves to the fine fraction with a grain size up to 0.6 mm (GOST 12865-67), reagent and technical Support salt in the following ratio of components, wt. %:

Portland84,0 - 85,2
Exfoliated vermiculite9,3 - 9,8
Support1,11-1,14
Technical Sol4,5 - 4,8

Exfoliated vermiculite is a product of thermal processing of natural hydromicas and subsequent grinding and fractionation. Produced according to GOST 12865-67. Is a large lamellar crystals of Golden-yellow or brown color. Upon heating of the plates are formed of worm-like posts or threads gold or silver color with a transverse division on finest scales (exfoliated vermiculite). Baked mass of exfoliated vermiculite� freely float on the water surface.

The chemical composition of exfoliated vermiculite corresponds to the formula (Mg+2Fe+2Fe+3)3[(AlSi4O10]·(OH)2·4H2O. However, exfoliated vermiculite rarely fits into the overall formula and usually contains impurities with the following properties:

- hardness on the mineralogical scale of 1-1,5;

is the density of exfoliated vermiculite - 0,065-0,130 g/cm3;

- the melting point of 1350°C;

- not susceptible to abrasion and lubricating properties similar to graphite;

- when heated to a temperature of 900-1000°C swells and increases in volume by 15-25 times.

Exfoliated vermiculite biologically resistant - not affected by decay and rot under the action of microorganisms and chemically inert - neutral to the action of alkalis and acids.

The lining is a complex reagent structurant, is a finely divided powder or powder with granules from yellow to creamy-brown. It is soluble in water. Produced by TU 2231-233-00147001-2001. Designed to produce high-quality cement slurries: normal density, light weight and ultra-light (for temperatures from 20 to 75°C).

Combined reagent as a structuring agent contains inorganic salt is a compound of aluminum from groups: hydroochloride, tetrahydrochloride, pentahydrochloride, AMO�MNLF aluminum oxide.

As fluid loss reducer is polyvinyl alcohol. As a defoamer - glyconutrient (http://www.freepatent.ru/patents/2259468; http://www.korund-ufa.ru/himreagent/himbur/40/good182.php; RU 2259468 C1).

Technical salt, chemical formula NaCl content with CaCl2, MgCl2, CaSO4and other impurities.

Specimen preparation grouting mixtures, determination of properties was made in accordance with GOST 1581-96 and 26798.1-96.

Light-weight backfill material comes on a rig in the form of prepared backfill mixture, where are poured into a mixing machine and other backfill materials.

Key indicators of the cement slurry density, flow, fluid loss, thickening time, the bending strength is determined in accordance with GOST 26798.1-96:

Density - pycnometer P-1;

Flow - on device CU-1;

The yield on the measuring cylinder;

The thickening time of the-on the consistometer "Obtained", model 130;

Flexural strength - on installation bend test (compression), Matest El60.

To conduct research prepare grouting solutions with component compositions:

Example 1: preparation of grouting mixture at 1000 g take dhe-1-100-84%, exfoliated vermiculite grade 300 - 8,5%, chemical reagent "Support" - 1%, industrial salt - 5%, water-solids ratio is 0.8. In tamping the mixture was added

water�. The resulting solution was stirred. The research is carried out according to GOST 1581-96.

Example 2: preparation of grouting mixture at 1000 g take dhe-1-100 - 84%, exfoliated vermiculite grade 300 - 9%, chemical reagent "Support" - 1.5 percent salt, technical salt 5%, water-solids ratio of 0.8. The solution was prepared and examined as in example 1. The data given in the table.

Example 3: preparation of grouting mixture at 1000 g take dhe-1-100 - 85%, exfoliated vermiculite grade 300 - 9,6%, chemical reagent "Support" - 1,2%, industrial salt 5%, water-solids ratio of 0.8. The solution was prepared and examined as in example 1. The data given in the table.

Example 4: preparation of grouting mixture at 1000 g take dhe-1-100 - 84,75%, exfoliated vermiculite grade 150 - 9,42%, chemical reagent "Support" of 1.13%, technical Sol 4.7%, and the water-solids ratio of 0.8. The solution was prepared and examined as in example 1. The data given in the table.

The data are shown in Table 1, indicate that the proposed backfill material has better strength properties than the known. In contrast to the known, the proposed light-weight backfill material is composed of a flexible and resilient filler - exfoliated vermiculite, which is not destroyed under the action of pressure and temperature.

When mixing cement slurry - exfoliated vermiculite, technical salt, "Kre�ü" and reducing the density of cement mortar to 1.52-1.53 g/cm 3high-tensile strength of cement stone in bending 3,2-3,4 MPa.

LIGHTWEIGHT BACKFILL MATERIAL

Lightweight backfill material containing Portland cement, expanded vermiculite, characterized in that it further comprises a reagent "Support" and technical salt in the following ratio of components, wt. %:

Portland cement grade PCT-1-10084,0 - 84,75
Exfoliated vermiculite9.3 to 9,42
Support1,11 - 1,13
Technical Sol4,5-4,7



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: before shank running-in horizontal ending is filled with clay mud of increased viscosity. The shank is equipped with centralisers in the densest parts in intervals of caving-in areas and is run-in at drill tubes with string disconnector up to interval of the horizontal ending commencement at low rate so that the string is moved constantly. During running-in of the shank the drill mud is levelled periodically. Upon running-in the process is withhold until the shank is set, setting of the shank is controlled, then the shank and borehole annulus are washed, drill tubes are screwed off from the shank, cement head is screwed on, cement solution is pumped through the shank to the borehole annulus and the shank borehole annulus is cemented. Upon running-out of drill tubes the process is withhold for the period of cement setting and hardening, cement remains in the shank and its fittings are drilled out, washed and the well is developed.

EFFECT: preventing accident rate at running-in of the shank in conditions of caving-in rocks in the well.

1 ex

FIELD: mining.

SUBSTANCE: in the process of construction of horizontal well, the deviated hole is drilled through the rocks, descending of the upper casing pipe, cementing the borehole annulus behind the upper casing pipe, drilling the horizontal shaft from the upper casing pipe to the lower oil reservoir, descending of the lower casing pipe with a partial placement of the latter in the lower part of the upper casing pipe, cementing the borehole annulus behind the lower casing pipe, perforation of the horizontal shaft, descending to the upper casing pipe of flow string with a packer with mounting of the packer and the shoe of the flow string in the upper casing pipe over the lower casing pipe, and performing the hydraulic fracturing in the horizontal shaft. As a part of the upper casing pipe in the interval of the upper producing layer the well casing of increased thickness are used, where the packer is placed. During the hydraulic fracturing of the lower oil reservoir the pressure is created over the packer, which is allowed on the upper casing pipe. Then the simultaneous release of pressure above and below the packer is carried out, perforating of the upper casing pipe is carried out in the interval of the upper oil reservoir, and development of the well. The height of the cement sheath between the packer top and the lower oil reservoir is determined from the ratio: LPHFLPOP2, where PHFL is pressure of hydraulic fracturing of the layer, MPa; POP is pressure in the over-packer space in the process of hydraulic fracturing of the layer, MPa; L is the height of the cement sheath between the packer top and the lower oil reservoir, m; 2 is the reliability coefficient of the cement sheath, MPa/m.

EFFECT: elimination of flows in the hydraulic fracturing crack, crushing the production casing above the place of the packer mounting, and reduction of water cut of the excavated product.

1 dwg, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: at stage cementing of the well cementing of the first stage is made, bottom plug is entered to the string in order to open circulating openings of cement collar for stage cementing, periodical washing of the borehole is arranged through circulating openings during waiting-on-cement time at the first stage, cementing of the second stage is arranged with entry of top plug to the string in order to close circulating openings of cement collar for stage cementing. At the first stage cementing oil-well cement is flushed by portions of drill mud, water and drill mud again, with setting of oil-well cement in annular space above the cement collar for stage cementing, and portions of water in the casing pipe within interval of the cement collar; during waiting-on-cement time at the first stage cyclic circulation of drill mud is arranged along the casing pipe through the cement collar with output to the wellhead through annular space until oil-well cement is removed completely within the interval of the cement collar for stage cementing; upon oil-well cement hardening at the first stage, at cementing of the second stage a portion of buffer solution and design volume of oil-well cement is pumped through the casing pipe, the top plug is placed and flushed by service water until it is set in the interval of the cement collar for stage cementing and openings of the latter are covered, pressure is increased in the casing pipe per 0.5-1.5 MPa above the operating pressure at pumping until openings of the cement collar are closed and waiting-on-cement time is started, and at well development the top plug is drilled out. Aqueous solution of surfactant and sodium tripolyphosphate is used as buffer solution.

EFFECT: developing simple and cheap method that guarantees performance of state cementing at high quality level.

2 cl, 3 ex

FIELD: oil and gas industry.

SUBSTANCE: device includes hollow casing with at least one top radial hole, at least one bottom radial hole, at least one outside longitudinal groove. The top radial hole is closed by the shear pin. The bottom radial hole is closed by ring spring-loaded sleeve with internal ring groove. From outside the casing there is enclosure creating with the casing the ring chamber. The device contains position switch with profiled groove, in which part of the hollow shear shift is inserted outside the casing. In the device bottom below the profiled groove of the casing the parker is installed. The ring sleeve ands position switch of the device are linked with each other using movable joint and are installed in the ring chamber with possibility of movement upon hydraulic connection of the casing cavity and profiled groove as per the switch code. One of these codes contains such device position when the casing cavity is hydraulically connected with the parker cavity via the bottom casing holes, internal ring groove of the ring sleeve and outside longitudinal casing groove.

EFFECT: increased reliability of device operation and extension of the scope of application.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: method of preparation of cement slurry using the cement mixing machine, cementing unit (CU) and cement surge tank comprises the cement mixing in grouting fluid. The obtained solution is pumped by the pump of the cementing unit through high-pressure injection hydroline into the cement surge tank. The obtained cement slurry solution is injected into the well through the high-pressure injection hydroline using another cementing unit. Meanwhile in one of the high-pressure injection hydrolines the hydromechanically acting cement slurry activator of the type "jet-to-jet" is connected. Jets flowing from two side conical hydromonitor attachments are facing to each other and form at contact the hydraulic shield. The central spray flowing from the conical attachment, equipped with insert, is directed perpendicularly to the hydraulic shield. Meanwhile the named hydromechanically acting cement slurry activator is connected to the high-pressure injection hydroline for pumping of cement slurry into the cement surge tank. And the insert of the central attachment of the hydromechanically acting cement slurry activator is selected with the possibility of forming of the centripetal flow. the subs equipped with the quick-detachable joint elements are screwed into connecting threads of the bushing and smaller stage of the housing.

EFFECT: increase of set strength, decrease of cement setting time.

3 cl, 4 dwg

FIELD: mining.

SUBSTANCE: in process of drilling in the area of impervious roof above the productive formation an extended annular chamber is created, which communicates with the intra-column space through openings of the special casing coupling. The chamber and the intra-column space are filled with hydro-sealing liquid which creates a constant excess of the hydrostatic pressure of the liquid column above the formation pressure of the gas.

EFFECT: improvement of efficiency and quality of creation of gas wells, the safety of their operation due to creation of reliable, more quality and permanently working hydro-sealing preventing the migration of gas through the borehole annulus.

4 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and may be used in construction of horizontal wells. The concept of the invention is as follows: horizontal well construction method includes drilling of a vertical section, a curved section and horizontal section, running of the casing pipe to the well and cementing. According to the invention drilling of a horizontal section is made with input to the productive stratum. Production string is run in with filtering lower part having length not less than the depth of input to the productive stratum. The packer is set above the filtering part of the string. A circulation valve is set above the packer and tubular annulus is cemented through the circulation valve. Upon cementing the packer is drilled out and drilling is continued with entry to the below stratum, rising to the productive stratum and drilling in the productive stratum.

EFFECT: improving increase of the production part of the well, area of its supply and increase of the well flow rate.

1 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: well completion method includes drilling, casing and cementing of the vertical borehole up to production horizon, drilling of a horizontal shaft. Water-saturated areas are identified. The perforated liner with open perforated holes is placed in the horizontal shaft, in the farthest part from the mouth with a cementing unit and perforated holes closed by acid-soluble plugs in the middle part and the whole part located closer to the mouth. Casing space of the liner middle part is cemented through the cementing unit with cement lifting up to the end to the whole part located closer to the mouth. The process is withheld for the period of cement hardening. Hydrostatic level is reduced and influx of reservoir fluid is obtained from the interval of the liner part farthest from the mouth. When influx is low, it is intensified in non-cemented part of the liner with shutoff of the remaining part by the packer with feedthrough hole. The plugged packer is set. Hydrochloric acid treatment is made for the middle part of the liner till magnesium plugs and part of the cement in casing annulus are dissolved. The well is flushed and influx is intensified from the medium part of the liner.

EFFECT: increase of well productivity.

1 dwg, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: disconnector contains a case 1 of the hanger, a supporting pipe 2, a nut 5, a coupling bushing 11 and a thrust bushing 7. The case 1 has step-like inner and outer surfaces. At the outer surface the nut 5 has a left-handed thread to interact with the case 1 of the hanger and a spline at inner surface to interact with the supporting pipe 2. The coupling bushing 11 is installed from inside at the end of the supporting pipe 2 and equipped with a suspended plug 13 and shear bypass plug 14. The thrust bushing 7 designed to fix a collar bearing 8 is installed at the end of the supporting pipe 2, which end is step-like. Outer diameter of the middle step is equal to inner diameter of the nut 5. Outer diameter of the low step is equal to inner diameter of the case 1 of the hanger and outside diameter of the collar bearing 8. The low step of the supporting pipe 2 is designed to unload the collar bearing 8 by its butt end and connected to the case 1 of the hanger with potential turn in regard towards each other and disconnection. The disconnector contains additionally a bushing 4 to connect the supporting piping to the case 1 of the hanger and to prevent turnout of the nut 5 during drilling, moreover the bushing 4 is spring-loaded and made with elements 9 for interaction with the case 1 of the hanger at butt end in order to prevent interaction during rotation. Outer diameter of the bushing 4 is less than outside diameter of the case 1 of the hanger in order to ensure rotation during disconnection. For the purpose of interaction elements 9 are made as male and female joint.

EFFECT: ensuring torque transfer to the right side of the bore bit.

4 cl, 7 dwg

FIELD: construction.

SUBSTANCE: circulation unit for a casing liner comprises a housing placed in the bottom part of a transport column above the unit of its coupling with the liner. The housing is made with a filling hole in the bottom part, overlapped by a shear sleeve and a circulation hole in the top part. A sealing member is placed on the housing. The circulation unit comprises an injector with a circulation hole placed on the housing above the sealing member and overlapping the circulation hole of the housing. There is a distribution sleeve with a radial opening, a peripheral axial channel and a catching baffle in its lower part. In this case the distribution sleeve is placed in the housing and designed with a possibility to provide the direct circulation of fluid through its axial channel with displacement of the fluid in space behind the liner, housing and above it - in the transport position of the device. Also, with a possibility of deformation of the sealing member by means of the injector and assurance of injection of a cement slurry through its axial channel, radial openings aligned with the filling opening, into the space behind the housing and below it, behind the liner according to the reverse circulation pattern with displacement of the fluid through the peripheral axial channel, space between the housing and the distribution sleeve, combined circulating openings of the housing and the injector into the space behind this injector and above it - in the operating position of the device.

EFFECT: increased reliability of the device operation.

2 dwg

FIELD: chemistry.

SUBSTANCE: reagent for treating drilling mud contains 94-96 wt % ferrochrome lignosulphonate and 4-6 wt % ammonium polyphosphate.

EFFECT: improved dilution properties of the reagent in salt mud, high thermal stability and environmental safety of the reagent.

3 tbl

FIELD: oil and gas industry.

SUBSTANCE: invention mainly relates to methods of hydrocarbons production from hydrocarbons containing reservoirs. Method of treatment of the reservoir containing crude oil including stages when: (a) composition is supplied to extract the hydrocarbons to at least part of the reservoir, at that the composition contains at least two internal olefin sulphonates selected from group comprising internal C15-18-olefin sulphonates, internal C19-23-olefin sulphonates, internal C20-24-olefin sulphonates and internal C24-28-olefin sulphonates, and at least one viscosity decreasing compound, that is isobutyl alcohol, ethoxylated C2-C12-alhohol, 2-butoxyethyl, butyl ether of diethylene glycol or their mixture, and (b) composition is provided with possibility to react with the reservoir hydrocarbons. Invention also relates to method of viscosity decreasing of composition of highly active surface-active substance and composition for hydrocarbons extraction.

EFFECT: result is creation of more effective method of hydrocarbons extraction from crude oil containing reservoir.

14 cl, 2 dwg, 2 tbl, 2 ex

FIELD: oil and gas industry.

SUBSTANCE: method of acid treatment of bottom-hole zone of carbonate reservoir includes injection of the acid composition containing in wt %: inorganic or organic acid, or their mixture 9.0-24.0; zwitterion surface-active substance - oleinamidopropylbetaine 1.0-10.0; hydrophobically-modified polyurethane polymer 0.05-3.0; water - rest, at that the acid composition is injected by single stage or by portions with holding between injections. The acid composition can additionally contain anionic surface-active substance in amount of 0.1-3.0 wt %. The above specified acid composition is injected alternating with injection of hydrochloric acid at 12-24% concentration.

EFFECT: alignment of profile of inflow of the production wells in carbonate reservoirs with non-uniform permeability, creation of new fluid conducting channels through entire perforated thickness of the reservoir, restoration of reservoir characteristics of bottom-hole zone due to its cleaning of mud solid particles.

3 cl, 1 tbl, 16 ex, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: method of water production zone isolation in a well involves sequential injection of coagulation agent (25% solution of calcium chloride), buffer layer of fresh water, and Givpan acrylic reagent. Additionally, polyethylene terephthalate production waste product, PET with low polymerisation degree, is added to Givpan as a filler in amount of 18-24 wt %.

EFFECT: reduced core permeability.

1 dwg, 7 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: lubricating additive for drilling mud, characterised by it is prepared by mixing polyglycol, a floatation agent - oxal, isopropyl alcohol and tall oil at 50-60°C for 2 hours, adding a mixture of a fatty acid methyl ether and diethanolamide of coconut oil, then triethanolamine, raising the temperature to 75-80°C and mixing for 2 hours, adding copper or copper-calcium stearate and oxyethylated nonylphenol, mixing for 1 hour and adding a neutralising agent to pH not lower than 6.5, with the following ratio of components, wt %: polyglycol 27.3, isopropyl alcohol 9.1, floatation agent - oxal 24.3, tall oil 24.3, copper or copper-calcium stearate 3, triethanolamine 4.5-5, fatty acid methyl ether 1-1.5, diethanolamide of coconut oil 1, oxyethylated nonylphenol 3-4.5, neutralising agent 0.5-2.

EFFECT: low friction of drilling mud in metal-metal and metal-filter cake pairs, low pipe and casing wear rate when drilling extended-reach and ultra-extended-reach wells.

2 tbl, 2 ex

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil-extracting industry, in particular to methods of insulation of inflow of formation waters and lining of the bottomhole zone of formation, and also to the methods for adjustment of profile of acceleration performance of injection wells, to the methods for formation treatment, to the methods for regulation of development of oil fields, and can be used for elimination of leakage of production strings and creation of behind-the-casing filter, for elimination of behind-the-casing gas-manifestations, tubing-casing pressure and inter-formation overflows in behind-the-casing space of a well. The method of insulation of inflow of formation waters and lining of the bottomhole zone of formation includes injection of mix of siliceous substance with high-disperse hydrophobic material. Also the alkaline drain of ShchSPK caprolactam production is injected. The siliceous substance are organic-silicon oil-soluble and water-soluble substances or organic-silicon substances with the following ratio of components, wt %: organic-silicon oil-soluble and water-soluble substances or organic-silicon substances 44.9-77.0; high-disperse hydrophobic materials 0.1-3.0; alkaline drain of caprolactam production 20.0-55.0.

EFFECT: increase of insulation of inflow of waters and lining of the bottomhole zone, increase in the oil-sweeping ability of injected compositions possessing plastic properties unlike a prototype, necessary for more effective elimination of the problem of sand production, elimination of leakage from production strings and creation of the behind-the-casing filter.

7 cl, 4 tbl, 5 ex

FIELD: oil and gas industry.

SUBSTANCE: acid composition for treatment of bottom-hole zone of carbonate reservoir contains in wt %: inorganic or organic acid, or their mixtures 9.0-24.0; zwitterion surface-active substance - alkyl betaine 1.0-10.0; hydrophobically-modified urethane polymer 0.05-3.0; water - rest. The acid composition can additionally contain anionic surface-active substance in amount of 0.1-3.0 wt %.

EFFECT: alignment of injectivity profile of injection or inflow profile of the production wells in carbonate reservoirs with non-uniform permeability, creation of new fluid conducting channels through entire perforated thickness of the reservoir, restoration of reservoir characteristics of bottom-hole zone due to its cleaning of mud solid particles, increased thermal stability of injected acid composition.

2 cl, 1 tbl, 16 ex, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: dry mixture comprises a copolymer of acrylamide and acrylic acid - 71.4-83.3 wt %, paraformaldehyde - 10.0-17.8 wt % and resorcinol - 6.3-11.4 wt % or copolymer of acrylamide and acrylic acid - 69.5-82.5 wt %, paraformaldehyde - 9.5-17.7 wt %, resorcinol - 6.1-10.6 wt %, and aerosil - 0.9-3.0 wt %. The gelling composition is prepared by dissolving any of the said compounds in water. At that the gelling composition without aerosil can also be obtained by the introduction of paraformaldehyde in water immediately after the copolymer of acrylamide and acrylic acid, and resorcinol - after complete dissolution of the copolymer of acrylamide and acrylic acid. The resulting gelling composition comprises a copolymer of acrylamide and acrylic acid - 0.17-0.80 wt %, paraformaldehyde - 0.03-0.20 wt %, resorcinol - 0.02-0.12 wt %, water - the rest, or a copolymer of acrylamide and acrylic acid - 0.17-0.80 wt %, paraformaldehyde - 0.03-0.20 wt %, resorcinol - 0.02-0.12 wt %, aerosil - 0.01-0.03 wt %, water - the rest.

EFFECT: increasing the efficiency and manufacturability of the gelling composition by ensuring the solubility in water used for its preparation of the dry mixture, simplifying of preparation of the composition at high mechanical and thermal resistance.

3 cl, 3 tbl, 5 dwg, 8 ex

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to inhibition of clay hydration during drilling and wells construction. Method of inhibition of clay hydration during drilling comprising use of water based mud containing from about 0.02 to about 5 wt % of bis-hexamethylenetetramine, salts of bis-hexamethylenetetramine or their mixtures as hydration inhibitor.

EFFECT: effective inhibition of clay hydration, stable inhibitor at ambient temperature, expansion of raw materials base due to wastes.

10 cl, 1 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to liquids for the hydraulic fracturing of subterranean formations in oil and gas extraction. The method of applying liquid for hydraulic fracturing in the formation of fracturing of subterranean formations includes the retardation of polymer splitting in the liquid for hydraulic fracturing at a temperature from 125 to 400°F, when the liquid for hydraulic fracturing contains a liquefier, by the combination of at least one radical acceptor with the liquid for hydraulic fracturing. The mixture for the application in the liquid for hydraulic fracturing contains a radical acceptor and a liquefier. The method of the hydraulic fracturing of subterranean formation includes the supply of the liquid for hydraulic fracturing, containing a propping means, a polymer and the liquefier, addition of the radical acceptor, supply of the liquid to a desired location in a subterranean formation to form at least one hydraulic fracturing, making it possible for the liquefier to split the polymer and reduce the viscosity of the liquid for hydraulic fracturing at a specified time or at a specified temperature. The invention is developed in dependent claims.

EFFECT: increase of viscosity control efficiency.

15 cl, 1 dwg, 1 ex

FIELD: construction.

SUBSTANCE: method of concrete mix preparation consists in preliminary mixing of 50% of rated amount of cement with tempering water containing superplasticiser - Relamix PK, and mechanical and chemical activation in a rotor-pulsation device with the number of rotations of the working organ of 5000 rpm for 2 min, with subsequent mixing of the remaining part of the cement and fillers.

EFFECT: increased strength, frost resistance and water impermeability.

2 cl, 1 tbl

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