Method of water production zone isolation in well

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

 

The invention relates to the oil and gas industry, in particular to methods used for isolation of water influx into the well.

Known methods of isolating zones of water inflow into the well by injection of compositions based on liquid glass (sodium silicate) with addition of various mineral and organic substances and water (patent RF №2494225, C09K 8/50, publ. 27.09.2013, bull. No. 27; No. 2494229, C09K 8/50, publ. 27.09.2013, bull. No. 27).

A common drawback of these methods is the low efficiency of isolation of water inflow due to low structural-mechanical properties of the compositions.

Known methods of isolating zones of water inflow through injection into the well of compositions based on cement (patent RF №2504640, E21B 33/138, publ. 20.01.2014, bull. No. 2; No. 2352766, E21B 33/138, publ. 20.04.2009, bull. No. 11; No. 2209928, E21B 33/13, publ. 10.08.2003).

The disadvantages of these methods are low filterability of cement mortars, small penetration depth into the formation, and insufficient mechanical strength, often leading to cracking of the stone during re-perforations, etc.

The closest in technical essence and the achieved result is a method of isolation zones of water inflow into the borehole, including a preliminary fix coagulant - 20% solution of calcium chloride, followed by pumping buffer layer of fresh water and hydrolysis�bathrooms in alkali waste fibers or fabrics of polyacrylonitrile (Gitana), then the pumping of fresh water and hydrochloric acid effect (patent RF №2270914, E21B 43/27, publ. 27.02.206, bull. No. 6). Polymer compositions based on Gaitana have a small density, good adhesion to metal and to the reservoir formation, corrosion resistant and have high filtration capacity [Shaidullin V. A. Application of polymer-acid treatment at low atmospheric temperatures // Engineering practice. - 7. - 2011. - P. 72-74].

The disadvantage of the prototype is the low efficiency associated with low initial concentration of coagulant that do not provide the full extent of the polymerization Gaitana due to dilution of the solution, a buffer, and a slight decrease in the permeability of the rocks in the method.

The task of the invention consists in increasing the efficiency of isolation of the zones of water inflow into the well.

The problem is solved in that in the method of isolation zones of water inflow into the borehole, comprising the sequential injection of the coagulant is calcium chloride solution, a buffer layer of fresh water and hydrolyzed in alkali waste fibers or fabrics of polyacrylonitrile (Gitana), as a coagulant using a 25% solution of calcium chloride, optionally the filler in Gaitan injected waste production of polyethylene terephthalate (PET) - PET with a low degree� polymerization rate of 18-24 wt.%.

Waste PET, which is a product of incomplete polymerization of PET, is non-toxic, water-insoluble and chemically neutral in relation to the applied reagents.

Hydrolyzed in alkali waste fibers or fabrics of polyacrylonitrile produced by THE 2216-001-04698227-99 under the trade name of "Gaitan". Physico-chemical parameters on the polymer givan given in table.1.

The mixture Gaitana with PET waste get with mechanical stirring in a stirrer for 10 minutes.

The effectiveness of the method was evaluated in the laboratory by filtering through the bulk samples and artificial cores.

To study the filtration process was designed to install, allowing to keep a constant differential pressure, a schematic diagram of which is shown in the drawing. The plant comprises a gas cylinder for pumping the investigated structures 1, a gas cylinder for side-crimping of the core 2, gears 3, 4 gauges, tank for pumped liquids 5, kindergaten 6, measuring cylinder 7, 8 valves.

The pressure on the side of the crimping of kindergaten and at the entrance to kindergaten through the intermediate tank 5 containing the studied compounds are created by using nitrogen from cylinders 1 and 2. The pressure at the outlet of kindergaten 6 is maintained at atmospheric. The number�tvo passed through the core liquid is measured with a graduated cylinder 7. If you want to create the high temperatures kindergaten can be placed in the oven. Filtering of fluids through the core sample can be performed in forward and reverse directions at a constant pressure drop across the core sample.

Bulk density cores were prepared as follows: at the output end of kindergaten welling tube with a tap to drain the fluid, then install the grille and mesh for holding sand, then stuffed river sand weight 118 g, thoroughly compacted and it is mesh with a lattice. In the empty space to the thrust ring is installed and welling inlet tube with valve for liquid supply.

Example 1. To conduct the study prepared samples of artificial cores with different porosity: 19, 24 and 27%. The bulk porosity of the cores was 34%. The water saturation of the cores was carried out in fresh water.

Through the cores consistently pumped 25 wt.% solutions of calcium chloride (33 ml), buffer (11 ml) and the mixture Gitana (33 ml) with different percentage of waste: 6, 18, 24, 30 wt.%. As the buffer used fresh water. The treatment efficiency was assessed by the decrease of the coefficient of permeability of the cores. The calculation was performed according to the Darcy formula [Gimatdinov S. K. Physics of oil and gas reservoir. - M.: Nedra, 1971]. The results of the study presented� in table.2 and 3.

As can be seen from table 2 and 3, the introduction of PET waste contributes to a significant reduction in the permeability of the cores due to mechanical clogging the pores. The optimal content of the waste in guitane is 18 - 24 wt.%.

Example 2. Experience were staged according to the scheme of example 1. Through the cores pumped sequentially solutions of calcium chloride, buffer and mixtures Gaitana with waste (24 wt.%). The concentration of calcium chloride in the solution was 20 and 25%. The results of the study are presented in table.4 and 5.

As can be seen from table 4 and 5, increasing the concentration of calcium chloride helps to reduce the permeability of the cores, due to more complete polymerization hispana.

Example 3. Experience were staged according to the scheme of example 1. Through the cores pumped sequentially solutions of calcium chloride, buffer and mixtures Gaitana with waste (24 wt.%). As a control, we have studied the samples of the cores treated according to the method specified in the prototype. The results of the study are presented in table.6 and 7.

As can be seen from table 6 and 7, the use of the claimed method of isolation zones of water inflow into the borehole allows to achieve higher values decrease�Oia permeability of cores in comparison with the prototype.

Thus, based on these data, we can draw conclusions about what is the most optimal method of isolation zones of water inflow into the borehole, comprising the sequential injection of the coagulant - 25% solution of calcium chloride, fresh water, and the mixture Gaitana with waste PET (18-24 wt.%).

Method of isolation zones of water inflow into the borehole, comprising the sequential injection of the coagulant is calcium chloride solution, a buffer layer of fresh water and Gaitana, characterized in that use 25% solution of calcium chloride, optionally the filler in Gaitan injected waste production of polyethylene terephthalate - PET resin with a low degree of polymerization rate of 18-24 wt.%.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: method for interval acidising of a horizontal well using a carbonate reservoir, which includes lowering a pipe string into a well; pumping acid compositions into the formation through the pipe string; conducting geophysical investigations in the horizontal well before treatment; selecting and separating intervals of the horizontal well into two groups; the first group includes intervals with permeability of 40-70 mD and water cut of the extracted product of 70-80%; the second group includes intervals with permeability of 5-39 mD and water cut of the extracted product of 50-69%; lowering into the horizontal well a pipe string plugged at the bottom and fitted with two packers with a perforated connecting pipe in between; performing consecutive treatment of the intervals of the horizontal well relating to the first group by sealed cut-off of each interval with subsequent alternating pumping into each interval in three cycles a temporary blocking composition at a rate of 6-12 m3/h, the temporary blocking composition used being a water-in-oil emulsion with dynamic viscosity of 120 mPa·s at 20°C, and an acid composition at a rate of 54-66 m3/h; after treatment of the intervals of the horizontal well relating to the first group, retrieving the pipe string from the horizontal well; at the mouth of the horizontal well, the pipe string is fitted with a liquid pulsator above the perforated connecting pipe and the pipe string which is plugged at the bottom and fitted with two packers with a perforated connecting pipe in between is once more lowered into the horizontal well; treating the intervals of the horizontal well of the second group by sealed cut-off of each interval with subsequent pulsed pumping into each interval a self-deviating acid composition based on a gelling agent at a rate of 24-36 m3/h.

EFFECT: intensifying oil extraction from a horizontal well, increasing oil yield and reducing the water cut of the extracted product.

3 dwg

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: 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: gas-cement grouting mortar contains, wt. pt.: grouting cement 100, aluminium powder 0.1-0.6, mix of a phosphanol and nitrilothrymetil phosphonic acid 0.02-0.05 at their ratio wt. pt. 1:1.5, water 50-53.

EFFECT: improvement of quality of cementation of wells and efficiency of works on cementing of loose weakly cemented rocks of bottomhole zone of formation during repair of wells due to use of gas-cement grouting mortar with improved process properties due to the lowered dynamic shear stress, increase of time of the beginning of gas emission and increased strength of cement stone formed at curing.

1 tbl, 4 ex

FIELD: oil and gas industry.

SUBSTANCE: invention relates to methods of current underground well workover. Method includes injection of silicon dioxide suspension that in itself does not have cementing properties, to cavities in the damaged cement enclosure or near it. At that silicon dioxide particles react with solidificated cement creating seals.

EFFECT: improved method.

8 cl, 12 dwg, 4 tbl

FIELD: mining.

SUBSTANCE: into the lower part of the impervious man-made screen containing dolerite rocks, the cement grouting is pumped, based on sulphate resistant or calcium aluminate cement with hardener (2% CaCl2) under pressure greater than hydrostatic, through the wells drilled from underground excavations. In the cement grouting the filler is used as mill tailings with a fraction of 0.1-0.25 mm, corresponding to fine sand. It is kept till hardening. After hardening the resulting rock-cement layer of the impervious screen is tamped with local injections of synthetic resins under pressure, less than the pressure of fracture of rock mass of mining protective pillar left under the screen. And the cement grouting is pumped under pressure of 0.7-0.8 MPa, and local injections of synthetic resin is carried out at a pressure of 0.5-0.6 MPa. The synthetic resin is used as hydro-active compositions based on LT-70 with the addition of a solvent - dimethylformamide in an amount of 20-25%.

EFFECT: increased strength and increased of impervious properties of the screen when filling the open pit.

6 cl, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: method of isolation of the water influxes to well comprises water isolation composition injection in the isolation zone, composition contains modified soluble glass, 3.6-10 or 1-3.5 parts by volume of ethyl acetate, and surface-active substance. At that in the water isolating composition 100 parts by volume of high-modulus soluble silicate with silica module 3.5-6 and density 1025-1200 kg/m3 is used as modified soluble silicate at temperatures exceeding 10°C. 0.2 parts by volume of detergent preparation with weight ratio of surface-active substances 30-38% and freezing temperature minus 30°C minimum are used as surface-active substance.

EFFECT: increased efficiency of water influx isolation and expansion of temperature range for the methods use.

2 cl, 2 ex, 2 tbl

FIELD: oil and gas industry.

SUBSTANCE: in method for elimination of behind-casing flows and inter-casing pressures, which involves preparation of aerated grouting mortars of light weight and normal density, their series delivery to a production string and squeezing to behind-casing and inter-casing spaces with squeezing liquid, as aerated grouting mortars of light weight and normal density there used are sedimentation stable fine-aerated solutions with densities of not higher than 1650 kg/m3 and not lower than 1800 kg/m3, which contain no extra Portland cement and heat-resistant plasticising and expanding additive including kaolin clay thermally activated at the temperature of 900÷1000°C with specific surface of 300÷400 m2/kg, aluminium sulphate, boric acid and an Aeroplast air-entraining additive excluding formation of stable foam, and mixing liquid at the following ratio of components, wt %: non-extra Portland cement 85-75, kaolin clay 10-18, aluminium sulphate 4.7-6.1, boric acid 0.2-0.5, Aeroplast air-entraining additive 0.1-0.4, mixing liquid over 100% till water-mixed ratios of 0.63÷0.65 m3/t and 0.40÷0.50 m3/t are obtained, with that, first, sedimentation stable aerated light-weight grouting mortar is delivered with controlled density of not more than 1650 kg/m3, then, aerated grouting mortar of normal density of not more than 1950 kg/m3 is delivered; with that, required densities of grouting mortars are provided by variation of a water-mixed ratio, intensity and duration of mixing, and squeezing is performed till partial displacement of aerated light-weight grouting mortar from behind-casing (inter-casing) space with squeezing liquid heated up to 50÷60°C during winter season and at cementing of low-temperature wells.

EFFECT: improving cementing quality.

2 tbl

Well treatment // 2549950

FIELD: textile, paper.

SUBSTANCE: method involves supply with a pump to a well shaft zone or to a bottom-hole zone of the well of a gel-forming material for protection against absorption of liquid mud (LCM) including a carrier liquid containing polymerising compounds. Material for protection against absorption also includes a polymerisation initiator and drops of an accelerator in covers, which is contained in them. Gel-forming material is subject to action sufficient for destruction of integrity of covers. Contact between polymerising compounds, the polymerisation initiator and the accelerator is provided.

EFFECT: improving absorption elimination efficiency.

20 cl, 3 dwg, 7 tbl, 5 ex

FIELD: oil and gas industry.

SUBSTANCE: invention is related to the technology intended for well productivity improvement. Large-volume selective acid treatment (LVSAT) for producers in carbonate reservoirs includes the injection to the well of an acid composite band with the specific volume of 1.5-3m3 per 1 m of an oil-saturated interval and non-linear viscous deflecting fluid before and/or upon the injection of the acid composite band, at that the injection of the acid composite is carried out with an optimal flow rate and an optimal ratio of a deflecting fluid volume to the acid composite volume, which are defined by mathematic modelling of the process considering changes in the wellhead and bottomhole pressure, type of the acid composite, type of the deflecting fluid, porosity and permeability of rock; at that for the purpose of the optimal flow rate optimisation for the acid composite injection dependencies of the optimal flow rate of injection on the specific volume of reagents injection are obtained with different constants of the reaction.

EFFECT: improved efficiency of large-volume selective acid treatment (LVSAT) for carbonate reservoirs.

2 cl, 5 tbl, 1 ex, 11 dwg

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: mining.

SUBSTANCE: plugging material comprises portland cement, microdispersed and expansion additives, fluid loss additive, the setting accelerator and water. The composition comprises the microdispersed and expansion additives as microdispersed cement complex MDCC consisting of: micro-cement or silica, or metakaolin and calcium hydrosulphoaluminate in a weight ratio of 2:1, respectively; the fluid loss additive - as water binding complex WBC consisting of a copolymer vinyl acetate and ethylene with vinyl acetate groups content of 18-20%, hydroxyethyl cellulose and modified organosilicon reagent in a weight ratio of 10:1:0.5, respectively; and the composition comprises the setting accelerator as calcium chloride or sodium chloride, in the following ratio of components, parts by weight: portland cement: 75-95; MDCC 5-25; WBC 2.0-3.5; the said setting accelerator 0.1-3.0; water 47-60.

EFFECT: increase in adhesion, strength characteristics, reduction of filtrate return and dynamic shear stress, improvement of indices of water and gas-blocking properties of the plugging material and formed cement stone.

2 tbl

FIELD: mining.

SUBSTANCE: insulating composition for protection from intensive absorption in the intervals of fissured rocks, comprising cement foam material CFM of grades A, B, C and D, water and setting accelerator, characterised in that the composition additionally comprises a plasticiser and a foam stabiliser, at that it comprises the setting accelerator as a mixture of potassium chloride and sodium carbonate in a weight ratio of 1:1, respectively, the foam stabiliser - as a mixture of low molecular weight hydroxyethyl cellulose and ethoxylated nonylphenol with 9 carbon atoms in the alkyl radical and 12 moles of ethylene oxide, attached to a mole of alkyl phenol, in a weight ratio of 0.4:1, respectively, and the plasticiser - as high-molecular anionic surfactant sodium polycarboxylate in the following ratio of components, mass parts: CFM - 100.0; the said setting accelerator - 8.0-12.0; the said foam stabiliser - 0.5-0.7; the said plasticiser - 0.5-0.9; water - 50.0-60.0.

EFFECT: increase in the insulating properties in elimination of absorption by reducing the setting time, increase in the strength and adhesion properties, increase in resistance to erosion.

2 tbl

FIELD: chemistry.

SUBSTANCE: method employs a polymer matrix based on metathesis-radically cross-linked mixture of oligocyclopentadienes. The polymer matrix has the following components, wt %: polymer stabiliser - 0.1-3.0, radical initiator - 0.1-4.0, ruthenium catalyst for metathesis polymerisation of dicyclopentadiene - 0.001-0.02, mixture of oligocyclopentadienes - the balance. After stirring at 0-35°C for 1-40 min, the mixture is added in the form of a laminar stream to an aqueous solution of a thickener. The thickener contains surfactants, has viscosity of 5-500 cP and temperature of 5-50°C. The formed microspheres are separated, heated in a medium of an inert liquid to 150-340°C and held for 1-360 min. The inert liquid used is heat-resistant silicone oil or synthetic mineral oil.

EFFECT: high output of microspheres and reduced swelling in oil.

5 cl, 32 ex

FIELD: oil and gas industry.

SUBSTANCE: composition for sediment removal from oil wells and bottomhole zone of reservoir includes aqueous solution A containing ammonium salt, surfactant and reaction trigger, and aqueous solution B of sodium nitrite, at volume ratio of the solutions 1:1. Solution A includes ammonium nitrate as ammonium salt, Netrol as reaction trigger, Nonoxynol as surfactant at the following component ratio, wt %: ammonium nitrate 10-40, Netrol 1-5, Nonoxynol 0.01-0.5, the rest is water; and solution B contains additionally Trilon B at the following component ratio, wt %: sodium nitrite 15-30, Trilon B 3-5, the rest is water.

EFFECT: improved efficiency of both organic and inorganic sediment removal and destruction in oil wells and bottomhole zone of reservoir, at low temperatures as well.

2 tbl, 9 ex

FIELD: production and exploratory well drilling, particularly foaming drilling fluids used during penetration through incompetent rock intervals and during primary productive oil and gas deposit opening in the case of abnormally low formation pressure.

SUBSTANCE: foam composition comprises surfactant, foam stabilizer, water, water hardness control additive and lubricant. The water hardness control additive is sodium silicate. The lubricant is VNIINP-117 emulsion. The foam stabilizer is polyacrylamide, the surfactant is sulphonole. All above components are taken in the following amounts (% by weight): sulphonole - 0.8-1.5, sodium silicate - 0.2-0.5, polyacrylamide - 0.1-0.5, VNIINP-117 - 0.5-2, remainder is water.

EFFECT: reduced power inputs for well drilling, as well as reduced coefficient of friction between drilling tool and well wall.

1 tbl

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