Treatment method of bottom-hole formation zone. RU patent 2494244.

FIELD: oil and gas industry.

SUBSTANCE: in a treatment method of a bottom-hole formation zone, which involves pumping to the formation of acid-oil emulsion of reverse type and acid, as acid-oil emulsion of reverse type there used is emulsion containing the following components, wt %: dispersion medium - hydrocarbon liquid 31-38, emulsifier - reaction products of aliphatic amines of fat acids of hydrated tall oil with hydrochloric acid in terms of amines 0.02-0.08, dispersion medium - synthetic, inhibited hydrochloric acid (10-18%) is the rest.

EFFECT: enlarging application area of the proposed method, use in wider range of formation temperature, use for well any water content of the extracted product, including increased water content, shortening of time required for treatment process, improving efficiency of influence on low-permeability productive zones of the formation, preventing secondary formation of emulsions under formation conditions after treatment, and reducing emulsifier consumption and use of a more technological method of emulsion preparation on a well.

7 cl, 21 tbl, 1 dwg

Field : oil producing industry and may be used for intensification of oil production from inhomogeneous permeability carbonate or terrigenous reservoirs by the acid treatment of bottomhole formation zone.

There is a method of treatment of bottomhole formation zone, including injection into the reservoir acid. (1) ( .., «Reference book on oil», M, «Nedra», 1974, ..420-432).

A well-known method is effective only when processing homogeneous on the permeability of the reservoir. During the processing of inhomogeneous reservoir chemical exposure are mainly high-permeability zones is practically not produced impact on the low permeability layer zones. Therefore, in the result of its implementation, is increased heterogeneity of the reservoir permeability. Method cannot be used in wells with high water cut of the extracted products.

A method of processing the well bottom zone, including injection into the reservoir material, resistant to acid, and acid solution. Injection material are under increasing pressure pumping, and acid solution - with lowering the pressure of injection. The initial pressure of the subsequent injection of the solution is planned at the level of the final pressure of the previous injection. Injection material is produced in larger quantities than acid solution. Injection material and acid solution to produce a cycle. After injection of solutions produce the technological holding. As an isolation material using the gel-forming solution of polyacrylamide, mud or other materials. Lower intervals overlap cement bridge. If necessary, the isolation of several intervals within the uncovered part of the layer, covering the whole interval cement bridge with its subsequent and opening of perforation of productive horizons. (2) (Patent RU №2114296, cl. 21 43/27, publ. 1998).

Disadvantages of this method are complex and difficult. When carrying out work on the isolation of high-permeability intervals (reservoirs) with recommended plugging materials and it is not excluded simultaneous irreversible loss of permeability tight productive formation zones. In addition, during the subsequent operation of the wells, for example, when translating the production well under pressure, will require an additional labour-intensive works on opening the previously isolated areas of the reservoir (e.g. opening their perforation with subsequent acid treatment). However, these works generally do not provide the complete restoration of permeability isolated intervals.

A method of processing the well bottom zone, including sequential injection into the reservoir material, resistant to acid in reservoir conditions and acid. Previously conducted research with the definition of injectivity of the insulated reservoir (interval), the results of which are prepared by plugging material appropriate concentration. As material, resistant to acids, use the material on the basis of clay. After isolation treated interval using two packers, is pumped into the reservoir plugging material is forced its fresh water with the subsequent technological exposure. Operation repeat until there is a significant increase of discharge pressure (reduction of water injection wells). Then, sequentially isolated with the help of two packers low-permeability productive intervals and spend acid treatment. (3) (Patent RU №2208150, cl. 21 43/27, publ. 2003).

Disadvantages of this method are complex and difficult. In the method will require further lowering and lifting operations with the use of packers. Moreover, the application for isolation of high-permeability zones material on the basis of clay can lead to almost complete loss of their permeability.

A method of processing well bottom-hole zone in multilayer oil Deposit, including sequential injection of all layers of the reverse oil emulsion injection at intervals of productive layers of the material, the solvent and the oil component of the oil emulsion and, after technological extracts, - processing each of the productive layers, isolated from the other layers by means of packers. (4) (Patent RU №2092686, cl. 21 43/27, publ. 1997).

Disadvantages of this method are primarily due to the complexity and the complexity of its implementation, requiring the holding of the repeated lowering and lifting operations with the use of packers and special material, the solvent oil component emulsion - waste production of isoprene.

In addition, the inverse emulsion has high viscosity, which limits the depth of penetration of it into the reservoir thus lowering the quality of the insulation of high permeability intervals. Not substantiates the possibility of full recovery of reservoir properties of low-permeability of productive layers after exposure to the material, the solvent and the oil component of the emulsion.

Closest to the invention of the technical nature of a way of processing of bottom-hole formation zone, including injection into the reservoir reverse oil emulsion and water solution acid, and as the inverse emulsion use emulsion, which contains the following components,%:

Hydrocarbon liquid

from 26 till 40

emulsifier

9601 or 9701

from 0.4 to 5

Aqueous solution of inhibited 10%

hydrochloric acid or or

aqueous solution 1-10%calcium chloride

or sodium

the rest of it.

As hydrocarbon liquids use diesel fuel, and liquid petroleum hydrocarbons paraffin series, or unstable natural gasoline, or light oil.

Inverse emulsion is stable for 6 to 35 hour at a temperature of 60 to 100 degrees C.

Download time inverse emulsion when filtering into the reservoir must not exceed the time of preservation of stability of the emulsion.

Emulsifiers (-9601 or -9701) are the products of reaction of amines and fatty acids of tall oil with solvents and additives. As additives in their composition includes nonionic surfactants (AF 9 -6 or AF 9 -12). (5) (Patent RU №2255215, cl. 21 43/27, publ. 2005).

The disadvantages of the prototype are:

- limited area of application: recommended interval reservoir temperatures is narrow range: from 60 to 100 degrees C. Does not apply at lower temperatures;

- periods of stability of emulsions prototype - from 6 to 35 hours cannot be considered optimal. Duration of process of processing of low-permeability formation zones usually does not exceed 1,5 hours. Therefore, the use of emulsions with periods of stability of the prototype (from 6 to 35 hours) leads to a significant delay the entry into operation temporarily isolated intervals and, consequently, improve the terms of completion of wells after treatment;

- applied on a prototype of the inverse emulsion can be effectively used for temporary isolation of high flow formation zones only at low water cut. When processing, for wells with high water cut crude production, simultaneously with the intensification of oil production may increase and of temporarily isolated zones the result of their processing released after the collapse of the emulsion hydrochloric acid;

- for the processing of low-permeability formation zones of the prototype is used only water solutions of acids, which is normally not efficient enough. It is well known that the chemical is affected only directly adjacent to the well bottomhole formation zone. This is due to the rapid neutralization with hydrochloric acid interacts with the carbonate rocks;

- applied on a prototype of emulsifiers stabilize the inverse emulsion not only when used as a disperse phase acid solutions, but also aqueous solutions of salts. This can create certain problems during the development of boreholes after processing associated with the possibility of secondary education emulsions in the bottom hole formation zone;

- for the preparation of emulsion on a prototype have a very large amount of emulsifier, to 5% (by volume). For cooking, for example, 10 m 3 emulsion required 0,5 m 3 or over 450 kg emulsifier. In addition, the use of special technical means (special mixer or installation -1).

The objective of the present invention is to increase the efficiency of the method by:

- application way over a wider range of reservoir temperatures: from 30 to 110 C;

- reduction of terms of treatment;

- application of the method for wells with anyone, including, with high water cut crude production, with the collateral, along with the intensification of oil production, reduction of water flow in well;

- improving the effectiveness of impact on the productive zones of low permeability of the reservoir;

- prevent secondary education emulsions in situ after treatment;

- to reduce consumption of emulsifier and the use of more sophisticated method of preparation of emulsion on a well.

Essence the present invention is that in the known method of treatment of bottomhole formation zone, which includes the injection into the reservoir emulsion reverse type and acid, according to the invention, as emulsion reverse type use emulsion, which contains the following components, mass%:

Dispersion medium - hydrocarbon liquid

Emulsifier - products of the reactions of aliphatic

amines hydrogenated fatty acids of tall

oil with the hydrochloric acid,

per amines

from 0.02 to 0.08

Dispersed phase - synthetic,

inhibited 10-18%hydrochloric acid

the rest of it.

The inverse emulsion at temperatures from 30 to 110 C has an adjustable period of stability within 0.5 to 5.0 hours.

Moreover, the inverse emulsion is used for the limitation of the water in the well.

In addition, the inverse emulsion is used for the impact on low-permeability formation range.

As the dispersive environment use of light oil with a small content of asphaltenes and resins, diesel fuel or other light petroleum products.

hole treatment spend many times.

In the proposed method, in contrast to the known method, emulsion reverse type stabilizes more effective emulsifier - products of the reaction of aliphatic amines hydrogenated fatty acids of tall oil with hydrochloric acid.

It is known that the main properties of amines are due to the atom N free pair of electrons. With mineral acids amines form salts, for example (hydrochloric acid) - RNH 3 Cl - . (6) («Chemical encyclopedic dictionary». Moscow, «Soviet encyclopedia», 1983, p.41, «Amina»). This reaction is realized in the process of preparation of emulsion on the claimed method: preliminary dissolved in hydrocarbon liquid dispersion medium) aliphatic amines hydrogenated fatty acids of tall oil react with dispersed by hydrochloric acid (dispersed phase). The product of this reaction and the actual emulsifier inverse emulsion for the claimed method are chloramines - RNH 3 Cl - .

The application of this emulsifier provides obtaining reverse emulsion type while minimizing the use of amines in the range of 0.02 to 0.08% in may. By the method prototype consumption emulsifiers (-9601 or -9701) is much higher than the 0.4 to 5% vol. Important the quality of the applied reagent-emulsifier is the fact that it is formed and is an effective emulsifier only when used as a disperse phase acid solutions. When this prevents secondary education emulsions in reservoir conditions after the neutralization of the acid and contributes to a more complete extraction of the formation of reaction products after processing.

Used emulsifier has a surface activity, decreases the value of the phase of the surface tension on the boundary of «hydrocarbon liquid acid solution and reduces the size of globules dispersed phase (acid solution).

Viscosity of used emulsions relatively low: under normal conditions of 250 to 350 MPa·C. With increasing temperature viscosity of emulsions greatly reduced. Therefore emulsion heating during discharge it to the bottom of the borehole, to the processed object has a low viscosity.

All this allows for deeper penetration emulsion not only in high-permeability isolated zone of formation, but also, which is very important for further processing in low-permeability productive intervals.

In the proposed method, in contrast to the known method used in temperatures ranging from 30 to 110 C inverse emulsion with the adjustable period of stability in a range from 30 minutes to 5 hours, and emulsions, which are not destroyed (keep stability) in the reservoir temperature. The duration of the period of stability of the emulsion at a certain temperature is regulated by the concentration of emulsifier. The regulated acid content in emulsion and concentration of the acid.

In the proposed method, in contrast to the known method, use the inverse emulsion not only for temporary isolation of high flow formation zones, but for the limitation of the water in the well and the subsequent (after isolation) deeper chemical effect on the productive zones of low permeability of the reservoir. The duration of stability of used emulsions change depending on their destination during the processing of bottom-hole formation zone:

- for temporary isolation of high flow formation zones use emulsion with elevated periods of stability, for example, from 1.5 to 5 hours.

The duration of these periods, as practice shows, not only provides a single impact on low-permeability productive zone of formation, but also to conduct drilling with large intervals of the opened part of the layer multiple treatments with the expansion of the scope of layer chemical exposure. Thus, in contrast to the known method, which is used for temporary isolation emulsion with unreasonably long period of stability - from 6 to 35 hours, significantly reduces the time of entry into operation temporarily isolated intervals;

isolation highly permeable formation zones apply emulsion, which is when the reservoir temperature is not destroyed (stable); later, if necessary, the use of separate intervals, for example, when translating well under pressure, permeability these intervals can be fully recovered by heating of a layer to temperature not less than 20 C exceed formation temperature. The emulsion loses stability and completely destroyed and its components can be easily removed from the bottomhole formation zone;

- for the processing of low-permeability productive formation zones (after isolation of high permeability zones) is used not just hydrochloric acid, and inverse emulsion with relatively small periods of stability in reservoir conditions, for example, 30 minutes to 1 hour; this greatly increases the effectiveness of treatment by active delivery acid into the reservoir.

The process of preparation of the emulsion, well before the holding of technological processing and does not require special equipment. Work is conducted according to the developed regulations, defining the modes of the discharge of the main components of emulsion (hydrochloric acid, hydrocarbon liquid) through camera with a fitting diameter of 8-10 mm

To implement the method uses the following reagents and commodity products. As the dispersive environment is used light crude oil with a low content of natural emulsifiers - asphaltenes and resins. It is allowed to use synthetic light oil products: diesel fuel, gasoline, kerosene and other.

As an emulsifier used products of the reactions of aliphatic amines hydrogenated fatty acids of tall oil and hydrochloric acid, obtained during the preparation of the emulsion. Amines hydrogenated fatty acids of tall oil are produced in the form of paste density 790 kg/m 3 , which at temperatures from 45 to 55 C to liquid state. Highly soluble in hydrocarbon liquids during heating up to temperature 50-60°C. Practically does not dissolve in water and aqueous solutions of salts.

As a disperse phase using synthetic technical hydrochloric acid, designed for the oil industry. It is recommended to use, for example, hydrochloric acid synthetic technical on GOST 857-95 additionally (inhibitor-2, 0,5%). Produced voao Khimprom, (, Volgograd) or hydrochloric acid manufactured by JSC «caustic», (, Volgograd) TU 2122-066-53501222-2007 (inhibitor Soling, 0,45%). Not allowed to use hydrochloric acid, derived from the portion of exhaust gases are industrial production, as it usually contains significant amounts of different admixtures, including solids (soot and others.), the number of which is not regulated. This complicates the preparation of inverse emulsions with adjustable periods of stability in reservoir conditions.

For machining of collectors with a low content of carbonate rocks (less than 20%) as a disperse phase apply a so-called «» - an aqueous solution, containing in its composition mixture of hydrochloric and hydrofluoric acids. The concentration of these acids usually is, respectively, within,% Mas.: from 12 to 13 and from 3 to 2.

The purpose of a substantiation of optimal compositions of used emulsions and estimation of their technological properties, laboratory studies and research testing in the wells. Using a primary amines hydrogenated fatty acids of tall oil, containing in its staff With 18 -82%and 16 -13%.

Laboratory studies conducted in the laboratory of OOO Scientific and production company (SPC) «Technoservice», a licensed laboratory OOO «Scientific - production center» (G. Kotovo, Volgograd region) and in the laboratory of the chair of physical, colloid chemistry and quality management of the Kuban state technological University, Krasnodar).

All the studies were conducted with the same methodology. If this were determined: sustainability emulsion reverse type when staying at temperatures from 30 to 110 C , surface tension on the boundary «acid - hydrocarbon liquid» and viscosity at different temperatures.

emulsion prepared in the following way. Heated estimated number of hydrocarbon liquid used as a dispersion medium, from 50 to 60 OC and dissolved in it estimated number of aliphatic amines hydrogenated fatty acids of tall oil in the process of mixing the solution for 15 minutes, this solution was injected into submerged jet estimated amount of hydrochloric acid, which is used as a disperse phase. Then prepared emulsion by mixing with a paddle mixer with the speed of 3000 rpm for 15 minutes.

Evaluation period of stability of the emulsion at a certain temperature conducted at the beginning of the allocation of acid in the lower layer. Simultaneously evaluated emulsion with the help of semi-automatic installation of -1, designed to assess the sustainability of hydrophobically-emulsion drilling fluid. In these tests, recorded the value of breakdown voltage between the two lowered in emulsion electrodes.

surface tension on the boundary «acid - hydrocarbon liquid with an emulsifier» was determined by the account drops by instrument design equipped with medical syringe and micrometric screw. In each experience of measurements made 20 times (formed 20 drops).

The magnitude of the phase surface tension is calculated by the formula

where V is the total volume drops, cm 3 ;

n is the number of droplets;

ρ 1 , ρ 2 - the density of solutions of acids and diesel fuel, g/cm 3 ;

g - acceleration of free fall, cm/2 ;

a - constant of the instrument;

b - the ratio V/n. The coefficient b (ratio V/n) was determined experimentally.

All of the following laboratory results obtained after the processing of the data obtained by the method of least squares.

The first series of experiments conducted with the purpose of substantiation of the optimum content of acid in the emulsion and the concentration of the acid to produce stable emulsions reverse type. Experiments were carried out at a temperature of 80 C with hydrochloric acid synthetic technical on GOST 857-95 additionally inhibited (- 2, 0.5%) and diesel fuel according to GOST 305-82.

The number of amines in all the experiments, it was constant and was, mg 100 ml emulsion: 40,42,44,45,47,48,50.

In tables 1-5 shows the results of experiments on the justification of optimal content of acid in the emulsion. The experiments were used hydrochloric acid 15% concentration. Volume content of acid in the emulsion was: 55,0; 57,5; 60,0; 62,5 and 65,0%.

Stability of the emulsion when 55% of the content of 15% hydrochloric acid by volume

The number of amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

Note: UTS. * - acid is not allocated, stable emulsion.

Stability of the emulsion when 57.5% of the content of 15%hydrochloric acid by volume

The number of amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

Note: UTS. * - acid is not allocated, stable emulsion

Stability of the emulsion at 60% of the content of 15%hydrochloric acid by volume

Number amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

Note: UTS * . - acid is not allocated, emulsion stable

Stability of the emulsion at 62.5% content of 15%hydrochloric acid by volume

The number of amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

Note: UTS * . - acid is not allocated, stable emulsion

Stability of the emulsion when 65.0% of the content of 15%hydrochloric acid by volume

The number of amines, mg/100 ml

Acid secretion from the emulsion when sludge within, h:

promotional.*

promotional.*

promotional.*

promotional.*

promotional.*

promotional.*

promotional.*

Note: promotional.* - acid secretion from the emulsion emulsion unstable

From the above data it can be concluded that stable emulsion reverse type can be obtained with a volumetric content of acid in the 55 to 62.5%. The higher the content of acid emulsion loses stability and quickly destroyed. Application of emulsion with low acid content inappropriate according to technological requirements.

In tables 6-10 shows the results of experiments on the justification of optimal concentrations of hydrochloric acid to produce stable emulsions reverse type. Volume content of acid in the emulsion in all the experiments, it was constant and amounted to 60%. Concentration of the acid changed in limits from 10 to 22.5%. Stability of the emulsion with a 10%hydrochloric acid

The number of amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

Note: UTS.* - acid is not allocated, stable emulsion. Stability of the emulsion with 15%hydrochloric acid

The number of amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

Note: UTS. * - acid is not allocated, stable emulsion

Stability of the emulsion with 18%hydrochloric acid

The number of amines, mg/100 ml

Acid secretion from the emulsion when sludge within, h:

Note: UTS. * - acid is not allocated, stable emulsion

Stability of the emulsion with a 20%hydrochloric acid

The number of amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

promotional. *

promotional. *

promotional *

promotional. *

promotional. *

promotional. *

Notes: promotional. * - acid secretion, unstable emulsion;

UTS. * - acid is not allocated, stable emulsion.

Stability of the emulsion from 22.5%hydrochloric acid

The number of amines, mg/100 ml

Acid secretion from the emulsion when staying within, h:

promotional. *

promotional. *

promotional *

promotional. *

promotional. *

promotional. *

promotional. *

Note: promotional. * - acid secretion from the emulsion emulsion unstable

The data in tables 6-10 data show that stable emulsions reverse type can be obtained at a concentration of acid in the range from 10.0 to 18%. When 20% of the acid concentration stable emulsion can be received only at high concentrations emulsifier per amines - not less than 50 mg per 100 ml of emulsion. At higher concentrations acid emulsion loses stability and quickly destroyed.

Based on the above data (table 1-10) in further studies acid content in emulsion was on the volume of 60%, and the concentration of the acid - 15%, falls within the established limits. The mass acid content in emulsion was about 67%.

Table 11 shows the results of experiments to determine the stability of the inverse emulsion depending on the number of amines (used for production of emulsifier). Experiments were carried out at temperatures from 30 to 110 degrees. emulsion used hydrochloric acid (inhibitor Soling, 0,45%) produced by JSC «caustic» (Volgograd) and diesel fuel according to GOST 305-82. Table 11 shows also the results of experiments with the use as the dispersive environment light crude oil with a low content of asphaltenes and resins. In experiments at 60C used oil sample Kotovsky field and at 80 C - sample oil Pamyatno-sasovskoye field. Data about these oil samples are given in table 12.

The data used in the experiments oil samples

No. well, mine

Density, kg/m 3

Content of asphaltenes, wt.%

Tar content, wt.%

№98,

№9, Memorably-Sasovo

№120, -Б

From the results of our experiments (table 1-11) followed by conclusions:

1. Emulsion with diesel fuel or oil are approximately the same stability; it shows a slightly higher stability of emulsions obtained with the use of light oil that is confirmed by the results of experiments on the evaluation of these emulsions are listed below in table 13.

2. Minimum concentration of amines to obtain inverse emulsion at different temperatures.

4. Recommended periods of stability of emulsions is in the range from 30 minutes to 5 hours. Emulsion with a smaller period of stability not meet the technological requirements of the way, and getting emulsions with large periods of stability, is difficult due to the fact that when further increase of the concentration of amines, dramatically increases the stability of emulsions with the formation of stable emulsions (not collapsing) at a given temperature.

5. The emulsion is not collapsing (preserving stability) at a given temperature recommended for the conduct of operations to control water flow into the well.

emulsions when using diesel and (or) oil

Dispersion medium

The number of amines, mg/100 ml emulsion/ breakdown voltage

Diesel fuel

Note: oil* - sample oil field Kotovsky.

Table 14 the results of field trials assessing the stability of emulsions at different temperatures depending on the number of amines. Data received in the course of treatment under the wells. Duration of stability of emulsions in reservoir conditions were assessed at the beginning of the growth of water injection wells in the process of discharge of the emulsion layer and testified to the beginning of the collapse of the emulsion with the release of the free acid and its interaction with the reservoir rocks. In this table for comparison of results of laboratory and field studies, the number of amines are described not only in kg/m 3 , and, accordingly, in mg/100 ml, as was the practice in the laboratory.

Field tests for assessment of stability of emulsions

Reservoir temperature, C

The number of amines,

Period of stability, min

mg/100 ml

Pamyatno-Sasovo

---«»---

-Б

Fig.1 presents, received by the results of laboratory and field tests (data in tables 11 and 14) the dependence of the stability of emulsions at various temperatures and concentration of amines. Conducted researches permit to conclude a pretty good comparability. The increased stability of emulsions from production data, compared with the results of laboratory researches, connected with the decline in the value of reservoir temperature in result of cooling the bottomhole formation zone in the process of discharge of the emulsion into the reservoir.

Carried out laboratory and field researches allowed to substantiate concentration amines to obtain inverse emulsions at temperatures from 30 to 110 C with periods of stability of 0.5 to 5 hours. They are: for laboratory studies ranged from 20 to 80 mg per 100 ml emulsion, and to fishing operations, respectively, from 0.2 to 0.8 kg/m 3 .

For producing emulsions remain stable (not collapsing) when the reservoir temperature used for the limitation of the water in the well, the recommended concentration of amines should be not less than 20% exceed the value of concentration amines, necessary for getting the emulsion with a period of stability during 5 hours. These emulsions have increased the value of breakdown voltage on these emulsions exceed 150 volts.

The ability to restore permeability of isolated zones of the layer with the use of emulsion, preserving the stability of the reservoir temperature, confirmed by the following experiments. Have two sample 100 ml emulsion containing by volume: 60% hydrochloric acid 15% concentration and 40% of oil Kotovsky deposits with amines in the amount of 40 mg of One of the samples put on crap at 40 degrees C. the Emulsion is stable for 5 hours. Then the two samples emulsion placed on crap at 60 C. After 80 minutes noted a violation of stability of emulsions. Then emulsion quickly collapsed with the release of acid. Repeated these experiments at 70 degrees C. Violation of stability of emulsions was noted in 15 minutes. Experiments indicate the possibility of destruction of emulsions, stable when the reservoir temperature, and the full restoration of permeability isolated areas of the layer by their warm-up to a temperature of not less than 20 C higher than the value of reservoir temperature. At higher temperatures the process of the disintegration of the emulsion is accelerated.

In tables 15-17 results of experiments to assess the possibility of formation emulsii in reservoir conditions after the neutralization of the acid. In these experiments, in contrast to the experiences with the hydrochloric acid, as a disperse phase used a main product of the reaction hydrochloric acid carbonate rocks-an aqueous solution of calcium chloride. The concentration of calcium chloride amounted to 2, 5 and 10% (mass). Stability of the emulsion with a solution of calcium chloride 2% concentration

The number of amines, mg/100 ml

Selection of a solution of emulsions in the sludge during, h

promotional. *

promotional. *

promotional *

promotional. *

promotional. *

promotional. *

promotional. *

Note: promotional. * - separation solution, unstable emulsion

Stability of the emulsion with a solution of calcium chloride 10% concentration

The number of amines, mg/100 ml

Selection of a solution of emulsions in the sludge during, h

promotional. *

promotional. *

promotional *

promotional. *

promotional. *

promotional. *

promotional. *

Note: promotional. * - separation solution, unstable emulsion

Tables 15-17 data confirm previous conclusion that used emulsifier is the product of the reaction of amines with hydrochloric acid and is therefore not a stabilizer emulsy with solutions of calcium chloride.

Table 18 shows the results of experiments on estimation of the value of phase surface tension on the boundary of «a hydrochloric acid diesel fuel with amines». During experiments used a hydrochloric acid of production of JSC «Kaustik» and diesel fuel according to GOST 305-82.

The number of amines, mg/100 ml emulsion

surface tension mn/m

From the table 18 data suggests that the applied emulsifier allows to reduce the magnitude of the phase surface tension more than twice.

Table 19 shows the results of experiments to determine the dependence of viscosity for the emulsion to the number of amines. The experiments were performed with the hydrochloric acid of production of JSC «Kaustik» and a sample of the oil Kotovsky field. The dependence of the viscosity of the emulsion from the number of amines

The number of amines, mg/100 ml

Viscosity of emulsions, MPa·s

The figures in table 19 data it can be concluded that with increasing concentration of the amines viscosity of emulsions . creates favorable conditions for the implementation of method: isolation of high permeability zones use emulsion with large periods of stability and, therefore, with higher concentrations emulsifier and with a relatively high viscosity, and for processing of low-permeability formation zones use emulsion with small periods of stability and , therefore, with small concentrations of emulsifier with lower viscosity.

Table 20 shows the results of experiments on estimation of the changes in the viscosity of emulsions, depending on the temperature. For the formation of emulsion used hydrochloric acid of production of JSC «Kaustik» and a sample of oil Pamyatno-sasovskoye field.

The number of amines to 40 mg per 100 ml of emulsion.

Viscosity of emulsions at different temperatures

Temperature, C

Viscosity, MPa·s

It can be concluded that, emulsion viscosity with increasing temperature in the process of its discharge to the bottom of the borehole repeatedly reduced.

In practice the claimed method is realized through the following operations.

Before processing the conduct preparatory work:

- design processing technology with the substantiation of the quantity and quality of used emulsions, as well as modes of discharge them into the reservoir, conduct laboratory experiments with samples of hydrochloric acid and light oil on the justification of the number of amines to prepare necessary emulsions;

- washed well before slaughter;

- establish a column of pump-compressor pipes (NKT) in the middle of the interval reservoir or in the upper part;

- determine the acceleration of the well;

- deliver for wells: oil for the preparation of emulsions and forcing them into the reservoir, hydrochloric acid, two storage tanks for receiving prepared emulsions, two pumping units, acid unit, mobile unit (PPU), «mixer-disperser» in the form of a camera rig fitting diameter from 8 to 10 mm; necessary for the preparation of emulsions amines;

- dissolved in oil, warmed with foam to 50-60°, the estimated number of amines in the process of mixing (pump works «for oneself») within 15 minutes;

- dilute hydrochloric acid with water to form a solution of 15% concentration;

- prepare the necessary emulsion according to the regulations of the applicant: simultaneously pump through the «mixer-disperser» acid and oil with amines, the ratio of expenditure acid and oil is 3:2, the General flow rate of liquids in the range of 0.3 to 0.5 m3 /min, pressure discharge - from 8 up to 10 MPa;

- prepared emulsion referred to a separate vessel;

- tie a pump and acid units with the mouth of the well a hard line and produce their hydrostatic into account the allowable pressure on the production casing.

In the course of processing consistently perform the following operations:

for an open annulus of the well consistently pump in the volume of tubing emulsion for temporary isolation of high flow formation zones and part of the emulsion for the impact on low-permeability productive intervals;

- close the annulus of the well and continue injection tubing in the remainder of the emulsion and liquid;

- close the hole and produce technological holding, usually within 3 to 5 hours.

Process control block of high flow formation zones and impacts on low-permeability zones carry out the change of water injection wells in the process of treatment.

Low intake capacity wells, is injected into the reservoir to the injection of the first portion of the emulsion and after each portion of a small emulsion amount of hydrochloric acid from approximately 1 to 1.5 m 3 .

Then learn well with the removal of the formation of reaction products and explore

the inflow for the evaluation of the results of processing and a substantiation of the optimum modes of operation.

The industrial testing of a claimed method. Works were conducted confidentially - without publication data applied for the emulsifier. The claimed method was called «the Way of processing of bottom-hole formation zone hydrophobic acid emulsions with managed stability ()».

For the treatments used synthetic technical hydrochloric acid of production of JSC «Kaustik» (inhibitor Soling, 0,45%) JSC «Khimprom» (inhibitor-2, 0,5%). Before processing acid is diluted with water up to 15% concentration. Volume content of acid in the emulsion was 60%.

As a dispersion medium used oil Kotovsky, Memorably-Sasovo or -Б fields.

At OAO « LUKOIL-» (now a branch of OJSC «RITEK» volgogradneftegaz TPP) were carried out industrial tests of the declared method with the purpose of limitation of the water in the well and the impact on low-permeability zone of the reservoir for well # 126 Kotovsky field.

Operational object: - horizon, outdoor barrel 2506-2494 m, reservoir temperature 75? C, reservoir pressure 24,95 MPa. Watering of the extracted products 86%.

Using a 10 m 3 emulsion. The number of amines - 6.5 kg (0.65 kg/m 3 ).

For the impact on the productive zones of low permeability of the reservoir is also used 10 m 3 emulsion. The number of amines - 4.5 kg (0.45 kg/m 3 ).

During the processing of the prepared emulsion consistently pumped into the reservoir.

At the beginning of discharge, there was a decrease of water injection wells up to 9 m 3 /day.·MPa. Then, after the collapse of the emulsion designed for processing of low-permeability formation zones and allocation of the free acid for interaction with formation rocks, pick-up wells increased to 283 m 3 /day.·MPa. After processing oil production increased from 3 tonnes. up to 20 t/day. The bore went on to gush waterless oil Well worked with a high production rate for 2 years, additional production amounted to over 8 thousand tons of oil. (A copy of the certificate №1 attached).

Also were carried out industrial tests of the declared method to improve the productivity of well №78 -Б LUKOIL-» (now a branch of OJSC «RITEK» CCI «Volgograd-Neftegaz»).

Operational object: - horizon, perforation interval 4747-4753 m, reservoir temperature 110 C reservoir pressure 39,1 MPa. Used to process 10 m 3 emulsion. The number of amines -7,35 kg (0,735 kg/m 3 ), which provided the emulsion with a two hour period of stability in reservoir conditions.

Before processing, a well weakly overflow with average daily flow rate amounted to 0.03 tonnes. After processing the well has moved on to gush with a rate of 17.9 t/day. A well worked for 2 years with a high production rate, additional oil production amounted to 10 thousand tons of oil. (A copy of the certificate №2 attached).

In JV «» were also carried out industrial tests of the declared method of 5 wells Pamyatno-sasovskoye field (№3, 6, 8, 12 and 15 ). All wells were performed per-interval treatment of bottomhole formation zone.

The volume of each portion of the emulsion used for formation treatment, depending on specific conditions, was changed within 5 to 10 m 3 . The number of amines in emulsions for temporary isolation of high flow formation zones through these holes with the reservoir temperatures from 74 to 77°C was from 0.48 to 0.49 kg/m 3 , and emulsions for impact the low permeability layer zones - from 0.44 to 0.46 kg/m 3 .

Analysis of the performed treatments showed that they have higher efficiency and are characterized by: a significant increase in the rates of productivity and permeability to a decrease in depression on the reservoir in the work of wells in various modes operation, increasing of the capacity of drained intervals.

Comparative characteristics of results of gas-dynamic surveys conducted before and after repair and isolation works are presented in table 21. (A copy of the certificate №3 attached).

This suggests high efficiency of the claimed process.

Sources of information:

1. .., «Reference book on oil», M, «Nedra», 1974, .420-432).

2. Patent RU №2114296, cl. 21 43/27, publ. 1998

3. Patent RU №2208150, cl. 21 43/27, publ. 2003

1. Way of processing of bottom-hole formation zone, including injection into the reservoir emulsion reverse type and acid, wherein as emulsion reverse type use emulsion, which contains the following components, mass%:

Dispersion medium - hydrocarbon liquid

Emulsifier - products of the reactions of aliphatic

amines hydrogenated fatty acids of tall

oil hydrochloric acid per amines

from 0.02 to 0.08

Dispersed phase - synthetic

inhibited 10-18%hydrochloric acid

2. The method according to claim 1, characterized in that the inverse emulsion at temperatures from 30 to 110 C has an adjustable period of stability within 0.5 to 5.0 hours

3. The method according to claim 1, characterized in that the inverse emulsion is used for the limitation of the water in the well.

4. The method according to claim 1, characterized in that the inverse emulsion is used for the impact on low-permeability formation range.

5. The method according to claim 1, characterized in that, as the dispersive environment use of light oil with a small content of asphaltenes and resins, diesel fuel or other light petroleum products.

6. The method according to claim 1, wherein the conduct hole treatment.

7. The method according to claim 1, characterized in that hole treatment spend many times.