Method of treatment of well bottomhole zone with low bed pressure

FIELD: oil-and-gas industry.

SUBSTANCE: method of treatment of the well bottomhole zone with low bed pressure means well washing with fresh water, renewal of the production formation perforation on the basis 10 holes per running meter of well, formations saturation with fresh water to 6MPa. The first portion of hydrochloric acid solution is injected to the well in amount 2.0m3 and is held under bath mode for 2 h. Injection to the formation is performed by four stages. At first stage 6 times pulse injection to the formation of specified first portion of hydrochloric acid solution is performed under cycle mode, including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection of the specified portion is completed under continuous mode until complete release of the well bore from the hydrochloric acid solution. At the second stage 6 times pulse injection to the formation of the second portion of the hydrochloric acid solution is performed in volume 3.0m3 under cycle mode, including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection is completed under continuous mode. Then process holding for 3 h is performed for reaction. At the third stage the third portion of the hydrochloric acid solution on the basis 0.5m3 per running meter of the production formation is performed under continuous mode at pressure 1-6MPa, and holding for reaction for 3 h is performed. At the forth stage the 6 times pulse injection to the formation of the second portion of the hydrochloric acid solution is performed on the basis 1.0m3 per running meter of the production formation under cycle mode including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection is completed under continuous mode. Holding for 3 h for reaction is performed, then reaction products are removed by swabbing.

EFFECT: improving treatment efficiency of the well bottom-hole zone.

1 ex

 

The invention relates to the oil industry and can be used at bottomhole zone treatment wells.

A method of processing bottom-hole zone of the well, including the injection of the acid solution [W. K. Gimatdinov. Reference book on oil production. M., "Nedra". 1974, S. 420-432].

The known method does not have sufficient efficacy in the treatment of bottom-hole zone of the well without additional operations.

Also known way [EN 2483201 C1, E21B 43/20, 27.05.2013], based on the periodic discharge of the working agent in injection wells, which use part of the production wells at a late stage of development of deposits by converting them in the discharge, and the discharge of the working agent is carried out at a gradual, over several months, the increase in pressure, precluding its breakthrough in the neighboring wells and up to values exceeding twice the pressure at the time of producing wells in injection and after as the volume of the injected working agent becomes equal to the volume extracted from the production well fluid during the entire period of development prior to the transfer of production wells into injection dramatically, from a condition of closing cracks layers of deposits, stop the injection of the working agent into the injection well, as a slave is what agent is used produced water formed during operation of producing wells.

The disadvantage of a relatively narrow scope.

The closest to the proposed invention the technical essence is a way of formation treatment [EN 2135760 C1, E21B 43/25, 27.08.1999], including injection interval in the bottom zone of the reagent, while pre-record the volume of the processing interval relative to the borehole bottom, the injection of the reagent is produced in pulsed mode: injection when the pressure receiving reagent perforation interval technological exposure at atmospheric pressure, hold repeat mode at low pressure injection of the reagent to reach the pressure of the working capacity of the well, perform the injection of the remaining amount of the reagent at the steady state pressure, conduct technology exposure and removing the reaction products and contaminants swabbing to the fluid withdrawal in the amount of not less than three times the volume of the injected reagent.

A known method can improve the permeability of the bottom zone of the well, but the method is not sufficiently effective when processing heavily kolmat bottom zones.

It is known that the productivity of the well is largely determined by the permeability of the bottom zone. Existing methods, including wybrany as the closest technical solution method means of hydrochloric acid BH treatment of wells with low formation pressure, especially in carbonate reservoirs, ineffective or are of a temporary nature.

The problem addressed by the invention is to improve the efficiency of processing bottom-hole zone of the well.

The required technical result is to increase the efficiency of processing bottom-hole zone of the well.

The problem is solved, and the required technical result is achieved in that in the processing method of the bottomhole zone wells with low formation pressures, including the phased injection into the bottom zone of the reagent, which is used as a solution of hydrochloric acid, technological shutter speed to respond and removing the reaction products swabbing, according to the invention before the injection of hydrochloric acid do rinse well with fresh water, update perforation of the productive formation is based on 10 openings per linear meter of the well and carry out the saturation of the reservoir with fresh water to 6 MPa, then carry out the injection of hydrochloric acid into the well in a volume of 2.0 m3and process exposure mode bath for 2 h and subsequent injection of the reagent consistently perform in four stages, the first of which is the injection of hydrochloric acid produced by 6-fold pulse injection of the first portion in the amount of 2.0 m3in the region of the press cycle, includes a 1 min injection at a pressure of 1-6 MPa, exposure 5 min to respond, and the final injection volume of hydrochloric acid in a continuous mode, in the second stage produces 6 times the pulse injection into the reservoir of the second portion of the hydrochloric acid in the amount of 3.0 m3in cycle mode, including a 1 min injection at a pressure of 1-6 MPa, exposure 5 min to respond and complete the injection volume of acid in continuous mode, then perform technological exposure 3 h reaction in the third stage are injected into the third layer portions of a solution of hydrochloric acid at the rate of 0.5 m3per linear metre of a productive formation in a continuous mode at a pressure of 1-6 MPa and perform technological shutter speed for reaction 3 h, and the fourth step are carried out in 6-fold pulse injection of the fourth portion of the hydrochloric acid solution is based 1,0 m3per linear metre of the productive formation in cycle mode, including a 1 min injection at a pressure of 1-6 MPa and endurance 5 min to respond, and then complete the download in continuous mode, perform technological shutter speed for reaction 3 h and transferred to the extraction of the reaction products swabbing.

- Implemented method of processing bottom-hole zone wells with low formation pressure, as follows.

The proposed method direction of the County to increase the pressure in the bottomhole formation zone and the slow penetration in the pore microtrading space carbonate rocks of hydrochloric acid in multi-cycle mode. This allows the most complete and high-quality to restore or increase the permeability of the bottom zone of the well due to the coverage layer processing in the depth and power. As a result, the efficiency of the method increases, resulting in increased productivity of the well.

- Implemented method of processing bottom-hole zone wells with low formation pressures sequential execution of the following operations.

1. The well is washed with fresh water (brine) water. Update the perforation of the reservoir, for example, perform cumulative perforation rate of 10 holes per linear meter of the well. Additional perforation holes contribute to the coverage of the entire thickness of the reservoir by means of hydrochloric acid treatment. After perforation saturate the treated reservoir freshwater reservoir (reservoir) water to a pressure of 6 MPa.

2. In the well by circulation when neposredno the packer pump 12% solution of hydrochloric acid in the amount of 2.0 m3and conduct technology exposure mode baths to respond within 2,0 o'clock This contributes to the slow penetration of the acid solution in the bottom zone and the dissolution of clogging compounds and particles of rock. After completion of the reaction time spend 6 times the pulse displacement of hydrochloric acid into the formation, which is done in cycle mode, containing the th 1 min injection at a pressure of 1-6 MPa inefficient pump, exposure 5 min to respond and post-injection in continuous mode until the complete liberation of the wellbore from the acid solution.

3. Bring up the layer and make the injection of the second portion of a 12% aqueous solution of hydrochloric acid in the amount of 3.0 m3conducted first pulse in mode 6 time: 1 min injection at a pressure of 1-6 MPa extract, 5 min to respond. Inject the remaining amount of acid still in continuous mode. Perform technological restraint to respond within a 3.0 hours

Pulse injection delay for the response, change the length of cycles allows the acid to penetrate into the low permeability zones of the reservoir, a series of "injection - discharge creates processes drainage layer zones, leads to the partial release of then collector from insoluble particles.

4. Lead up to the reservoir and produce the displacement of oil in a continuous mode at a pressure injection 1-6 MPa third portion of a 12% aqueous solution of hydrochloric acid at the rate of 0.5 m3per linear metre of the reservoir, technological restraint to respond within a 3.0 hours

5. Bring up the layer and are injected into the reservoir of the fourth portion of a 12% aqueous solution of hydrochloric acid at a rate of 1 m3per linear metre of the productive formation. First injection is produced in the pulse is lissom mode 6 times in cycle mode: 1 min injection at a pressure of 1 to 6 MPa, excerpt 5 min to respond. The remaining part of the hydrochloric acid solution is pumped in a continuous mode at a pressure of 1 to 6 MPa. Perform technological restraint to respond within 3 hours

6. Spend removing the reaction products and contaminants swabbing when planted the packer.

All downloads are performing inefficient pump with a flow rate of 20-80 m3day.

As a working agent for communication to the reservoir and the injection of the acid solution used in fresh water or marketable oil.

The proposed sequence of operations of the method and modes of operation tested in practice on real objects and presented in the most optimal option.

A specific example of the processing method of the bottomhole zone wells with low formation pressure.

Handle the bottomhole zone of the oil well depth 1173 m reservoir perforated at depths from 1111 to 1123 m the Density of the existing perforation is 10 holes per linear meter of the well. The collector of the bottomhole zone - carbonate, porous fractured. Well decommissioned at the current rate of 0.8 m3day.

Stop well and rinsed with fresh water. Update the perforation of the productive formation by performing cumulative perforation rate of 10 resp is RSTI per linear meter of the productive formation. Pumped into the well of fresh water to establish the pressure at the wellhead 6 MPa, the volume of the injected fluid was 435 m3. In the well by circulation pump solution of hydrochloric acid in a volume of 2 m3and bring it to the roof of the reservoir and conduct technology exposure mode bath for 2 hours Spend pulsed injection of a 12% aqueous solution of hydrochloric acid, which is done 6 times in cycle mode: 1 min injection at a pressure of 3 MPa, excerpt 5 minutes Then a solution of the acid cut through the oil in the amount of 1.6 m3in continuous mode.

Then produce a displacement in the layer of the second portion of a 12% aqueous solution of hydrochloric acid in a volume of 3 m3first 6 times in a pulse mode: 1 min injection, 5 min exposure. Inject the remaining amount of acid is continued at a pressure of 3.5 MPa in a continuous mode. Perform technological restraint to respond within 3 hours

Lead up to the reservoir and produce the displacement of oil in a continuous mode at a pressure of 4 MPa injection of the third portion of a 12% aqueous solution of hydrochloric acid in an amount of 6 m3(0.5 m3per linear metre of the productive formation). Perform technological restraint to respond within 3 hours

Next, bring up the layer and are injected into the reservoir of the fourth portion of a 12% aqueous solution of hydrochloric acid in a volume of 12 m3(1 m3on pogo the Ter m of the productive formation). First injection is produced in a pulsed mode 6 times in cycle mode: 5 min injection at a pressure of 4 MPa, excerpt 5 min to respond. The remaining part of the hydrochloric acid solution is pumped in a continuous mode at a pressure of 6 MPa. Perform technological restraint to respond within 3 hours

Spend removing the reaction products and contaminants swabbing.

As a result of processing under the proposed method, the growth rate in wells with low formation pressure was 3-5 m3/day with a duration of more than 7 months. When performing the traditional treatment of bottom-hole zone of the well in similar conditions increase the flow rate was not more than 1.0-2 m3/day and not longer than 1-2 months.

Thus, the application of the proposed method allows to achieve the desired technical result and to improve the processing efficiency of the reservoir to increase the productivity of the well planted with pressure.

The processing method of the bottomhole zone wells with low formation pressures, including injection into the bottom zone of the reagent, which is used as a solution of hydrochloric acid, technological shutter speed to respond and removing the reaction products swabbing, characterized in that before sakacc the second hydrochloric acid solution performs well wash with fresh water, update perforation of the productive formation is based on 10 openings per linear meter of the well and carry out the saturation of the reservoir with fresh water to 6 MPa, and then carry out the injection of hydrochloric acid into the well in a volume of 2.0 m3and process exposure mode bath for 2 h and subsequent injection of the reagent consistently perform in four stages, the first of which is the injection of hydrochloric acid produced by 6-fold pulse injection of the first portion in the amount of 2.0 m3in cycle mode, including a 1 min injection at a pressure of 1-6 MPa, exposure 5 min to respond, and the final injection volume of hydrochloric acid in a continuous mode, in the second stage produces 6 times the pulse injection into the reservoir of the second portion of the hydrochloric acid in the amount of 3.0 m3in cycle mode, including a 1 min injection at a pressure of 1-6 MPa, exposure 5 min to respond and complete the injection volume of acid in continuous mode, then perform technological exposure 3 h reaction in the third stage are injected into the third layer portions of a solution of hydrochloric acid at the rate of 0.5 m3per linear metre of a productive formation in a continuous mode at a pressure of 1-6 MPa and perform technological shutter speed for reaction 3 h, and the fourth step are carried out in 6-fold impulsesaut in the formation of the fourth portion of the hydrochloric acid solution is based 1,0 m 3per linear metre of the productive formation in cycle mode, including a 1 min injection at a pressure of 1-6 MPa and endurance 5 min to respond, and then complete the download in continuous mode, perform technological shutter speed for reaction 3 h and transferred to the extraction of the reaction products swabbing.



 

Same patents:

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises recovery of core, making of core specimens and their analysis at electronic scanning microscope. Chemical reagent is forced through prepared specimens and sections are made at entry and exit of said chemical reagent. X-ray tomography is used to analyse the core specimens after forcing though of said chemical reagent. Images are compared to isolate the most efficient forms of solution channels. Numerical value of acid processing efficiency is calculated by computer processing of characteristics of images produced with the help of tomographic scanner. Minimum numerical value of said efficiency is selected as a criterion of the highest efficiency of acid processing. Note here that magnitude of stimulation is used as the numerical value of acid processing efficiency. Note here that, first, software is used for automatic determination of bored hole propagation volume. Then, acid solution penetration depth is computed. Now, stimulation magnitude is calculated by mathematical formula.

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FIELD: oil-and-gas industry.

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2 tbl, 4 ex

FIELD: oil and gas industry.

SUBSTANCE: method of oil formation treatment includes running of a string with a packer to the well, setting of the packer above the oil formation and subsequent injecting and flushing through the string to the oil formation of hydrocarbon solvent and acid agent in volumes exceeding filtration resistance in the formation zone remote from the well over the same value in the bottomhole zone, process withheld and removal of waste reaction products from the treated area by depression impact on the well. Then the pipe string at the well mouth below the packer is equipped with impulse liquid pulsator. At that a valve is mounted between the packer and liquid pulsator. An ejector pump with a feedthrough accessory is mounted above the packer. The string is run in to the well so that the packer is placed above the formation. Hydrocarbon solvent is injected to the string in pulsed mode, the packer is set, and hydrocarbon solvent is flushed to the formation by process fluid under pressure not exceeding the permitted pressure to the formation. The packer is released and the well remains under exposure. Then the well is washed out and acid solution is injected to the well, the packer is set, acid solution is flushed to the formation by process fluid under pressure not exceeding the permitted pressure to the formation. The packer is released and the well remains under exposure. After exposure period the valve is actuated and impulse liquid pulsator is cut off. The packer is released, the string is run in additionally so that radial openings of the valve are opposite the formation; the feedthrough accessory is removed from the ejector pump and a blind plus is installed instead. Then the packer is set, and reaction products are extracted by process fluid injecting along the string through the ejector pump and the well is completed through its tubing-casing annulus above the packer.

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4 dwg

FIELD: oil and gas industry.

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3 ex, 3 dwg

FIELD: oil and gas industry.

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2 ex, 2 dwg

FIELD: oil-and-gas industry.

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3 ex, 1 dwg

FIELD: oil-and-gas industry.

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3 ex

FIELD: oil-and-gas industry.

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EFFECT: increased processing depth, higher efficiency.

1 ex

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises lowering of flexible pipe into gas well production tubing to well bottom and its cleaning of water and impurities by service water treated with surfactant and water-repellent and thickened by two-percent solution of carboxymethyl cellulose. Then, flexible pipe is lifted to lower holes of perforation interval. Then, acid solution is injected in said pipe into perforation interval at slow lifting of said pipe at the rate of 2 m/s. Said acid solution contains the following components in wt %: citric acid 10-20; non-ionic surfactant "ОП"-10 1-2; Trilon "Б" 0.2-0.5; water making the rest, in the volume of 0.2-0.5 m3 of effective perforated depth. Buffer gas or inert gas is used to force acid solution in the bed. Flexible pipe is, then, lifted to keep the well for axis solution reaction with mid compounds.

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1 dwg, 3 ex

FIELD: oil and gas industry.

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EFFECT: improving treatment efficiency of a bore-hole zone.

3 dwg

FIELD: oil and gas production.

SUBSTANCE: invention aims at increasing productivity of oil- and gas-producing and injecting wells exposing high-temperature low-permeable oil reservoirs. In the treatment method according to invention including forcing enzyme substrate and separate enzyme into formation and creating conditions to enzymatically convert substrate into acid, geologic and productive characteristics for each interval of bottom zone are determined in order to pick out low-permeable intervals of oil reservoir for treatment, whereupon properties of enzyme substrate and separate enzyme as well as conditions for their pumping are chosen. Substrate utilized in the method is head fraction of methyl- and/or ethyl-, and/or butyl acetate production, to which aliphatic alcohols are added, and enzyme is an acid solution. Substrate is pumped simultaneously and/or before, and/or after pumping of enzyme, after which well is closed for some time and then opened and placed under predetermined operational conditions.

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25 cl, 1 tbl, 3 ex

FIELD: oil and gas extractive industry.

SUBSTANCE: device has pipe-like body with detachable upper and lower sleeves. Concentrically to body, with possible rotation relatively to it, a cover is mounted with blades with scrapers placed spirally on its surface. To lower sleeve a reactive end piece is connected with slit apertures. End piece hollow is filled with granulated material engaging in exothermal reaction with acid. Lower portion of end piece is provided with check valve. Upper sleeve is provided with check valve having locking element in form of sphere with shelf and centering elements, to be dropped from well mouth. Base of saddle of check valve is made in form of disc having diameter equal to diameter of body. Pass aperture of saddle in lower portion is overlapped with easily destructible and easily removed element. Length of sphere shelf is greater than height of pass aperture of saddle of check valve of upper sleeve.

EFFECT: higher reliability, higher efficiency, broader functional capabilities of device.

3 cl, 4 dwg, 1 tbl

FIELD: oil and gas production.

SUBSTANCE: invention relates to compositions used for intensifying wells owing to increasing permeability of rocks forming well bottom zones. Composition of invention contains 7.0 to 30.0% ethanol, 0.1 to 0.3% cupric chloride, 0.1 to 0.5% alkylbenzenesulfonate, and trichloroacetic acid (to 100%).

EFFECT: increased dissolving capacity of composition with respect to asphaltene-tar and paraffin deposits filling crack and pore space of rocks forming well bottom zones.

1 tbl

FIELD: oil and gas production.

SUBSTANCE: invention provides composition that can be used to intensify oil inflow and to develop well by means of acid treatment of terrigenous oil reservoir as well as to intensify oil inflow and to increase oil recovery of formations with the aid of hydraulic rupture of formation assisted by acid solutions. Composition contains borohydrofluoric acid needed to create borosilicate films prohibiting migration of particles during acid treatment. In addition, composition is characterized by lowered rate of reaction with rock at formation temperature in order to extend coverage of formation by treatment and to diminish deposit formation risk, low surface tension, low corrosion rate, and compatibility with inhibitors added to commercial acid, which will enhance efficiency of acid treatment using composition of invention. Composition is made up of, wt %: inhibited hydrochloric acid 8.0-15.0, fluorine-containing reagent (hydrofluoric acid, ammonium bifluoride, or ammonium fluoride) 1.5-10.0, boric acid 1.0-3.0, additionally isopropyl alcohol 5.0-10.0, and "Alkylfosfat-Khimeko" or "Efiroks-7", or "Fosfol-10" 0.5-2.0, and fresh water to 100%. In a method of acid treatment of the bottom area of terrigenous formation comprising consecutively pumping flushing fluid and acid composition into borehole, forcing the latter into formation by the aid of flushing fluid, giving time (up to 8 h) for reaction and subsequent removal of reaction products. Acid composition is used as it is or in the form of aqueous solution obtained by diluting composition with fresh water at water-to-composition ratio (1-5):1 in amount corresponding to 0.5-2.0 m3 per 1 m of perforated thickness of the formation. As flushing fluid, 1.5-3.0% ammonium chloride solution is used in amount 0.5-1.5 m3/m before pumping of acid composition or in amount 1.0-5.0 m3/m when used to force acid composition.

EFFECT: expanded useful possibilities of acid composition.

2 cl, 1 dwg, 2 tbl, 4 ex

FIELD: oil recovery industry, in particular buildup of reservoir recovery of low permeable, clay-containing beds.

SUBSTANCE: declaying composition contains clay dispersing reagent, peroxide compound and water, wherein as peroxide compound potassium fluoride peroxysolvate in activated form, comprising 1-3 mass % of oxalic or salicylic acid; and includes two sequential technological solutions. More specifically claimed composition contains (mass %): technological solutions 1: potassium fluoride peroxysolvate 1-2.5; hydrochloric acid as clay dispersing reagent 3-8.0; and balance: water; technological solutions 2: potassium fluoride peroxysolvate 1-2.5; sodium hydroxide as clay dispersing reagent 4-6.0; and balance: water. In addition said solution contain 0.1-1.0 mass % of water soluble surfactant. After treatment with disclosed solutions and well exposure dispersed reaction products are removed from bottom-hole formation zone.

EFFECT: bottom-hole formation zone of improved permeability due to effective removing of clayish and other mudding materials.

3 cl, 19 ex, 3 tbl

FIELD: oil and gas industry.

SUBSTANCE: method includes acidic treatment of bed, calculation of hardness decrease and pressure of rocks tearing and pressure for pressing working solution into bed, completion of well and the actual hydraulic tear. Pressure for pressing is determined from formula Pht=(2μ·Pm/(1-μ)+(1-3μ)·Pb/(1-μ), where Pht - rocks tear pressure, Pm - mountain pressure, Pb - bed pressure, μ - Poisson coefficient.

EFFECT: higher yields.

1 ex, 1 tbl

FIELD: oil industry.

SUBSTANCE: method includes treatment of face area of oil bed by hydrophobic powder in organic and pushing oil away from collector with following delivery of oil from face-adjacent area of extraction well for processing of oil-containing terrigenic bed into organic solvent additionally inserted is copolymer of ethylene with vinylacetate, well treatment is performed with relation of components in percents of mass: said powder 0.05-2, said copolymer 0,05-2, organic solvent - the rest.

EFFECT: higher efficiency.

2 tbl, 2 ex

FIELD: oil extractive industry.

SUBSTANCE: method includes determining porosity, penetrability and oil saturation level of shaft-adjacent area along whole length of deflected shaft. On basis of these ranges with low penetrability are detected, caverns presence level and diameters of shaft on ends thereof are determined. With consideration of characteristics of detected ranges at surface a pipe assembly is assembled, at end of which a ring saddle is mounted for locking ball, on both ends - hydraulic packers. Between these in assembly pipe a radial through calibrated channel is made. Pipe assembly is fixed at end of pipes column and these are lowered into chamber to level of deflected shaft mouth. With unpacked packers straight and backward washing of shaft is performed. After that acid is pumped into well in amount, equal to amount of first treatment range. Locking ball is dropped, first from the face shaft range with low penetrability is packed and concurrently acid is pressed therein, after that well is left for reaction. Then both packers are unpacked, backward washing of shaft is performed. By raising pipe column, pipe assembly with packers is transferred in backward, from face, direction into area of second, from face, range with low penetrability and above-mentioned operations are repeated. In turns, operations with each treatment range are performed.

EFFECT: higher efficiency.

2 cl, 6 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes serial pumping of film-forming hydrocarbon liquid and hydrochloric acid with adding of salt-acidic corrosion inhibitor to these, as said inhibitor a special paraffin deposits inhibitor is used, in form of composition of surfactants and aromatic solvents, while hydrochloric acid with addition of inhibitor before pumping is dispersed with gas to receive foam.

EFFECT: higher efficiency.

3 ex, 3 tbl

FIELD: oil and gas industry.

SUBSTANCE: method includes injection of processing liquid into bed, which liquid contains solved or dispersed in water complicated ether and polymer destructor, selected from oxidizing destructor and ferment destructor in such a way, that complicated ether is hydrolyzed with production of organic acid for solution of material soluble in acid, present in filtering layer or adjacent to it or in other damage in productive bed, and polymer destructor destroys polymer material, present in filtering layer or bio-film in productive bed.

EFFECT: higher efficiency, simplified method, higher productiveness, higher ecological safety.

31 cl, 1 tbl, 1 ex

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