RU2313560C1 - Composition for leveling injectivity profile of injection wells and limiting water inflow in production wells - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: composition contains more than 60-70% of heavy asphaltic-resinous crude oil having density 900 kg/m³, 5-13% of nonionic surfactant OP-7 or Neonol Af_9-6, and balancing amount of "fusel oil" as regulator-solvent.

EFFECT: achieved high efficiency of composition al low cost.

3 dwg, 5 tbl

Description

The invention relates to the oil industry, in particular to compositions for leveling the injectivity profile of injection wells and limiting the flow of water in production wells.

A known composition and method of preparing inverse emulsions for regulating the injectivity profile of injection wells and / or isolation of water inflow in producing wells (Patent RU No. 2126082 C1, bull. No. 4 of 1999).

The lack of composition and method - requires the use of special dispersing devices for the preparation of finely dispersed (globule size no more than 10 microns) emulsions of the inverse type and the high viscosity of the resulting concentrated emulsion, which limits the scope of this composition only for the treatment of highly permeable and fractured reservoirs.

Known compositions for oil production based on hydrocarbon and / or oil solutions of surface-active substances (surfactants) having ultra-low interfacial tension at the oil-water interface, which determines their ability to spontaneously form emulsions of the inverse type, such as "water in oil", and direct type, such as "oil in water". Such formulations, called “soluble oil” (Holm Le Roy W. “Solube oilcomposition”, Union Oil Co of CoI California, US Patent 252-8.55 D, E21B 43/16, No. 3691072), contain, wt.%: Liquid hydrocarbon ( oil with a density of 750-850 kg / m ³ ) 45-90, surfactants (alkylarylsulfonates) 4-30, polar solvent (secondary butyl alcohol) 0.5-0.8 and the salt of the monovalent cation (NaCI or KCI) 0.01- 0.15. Upon contact with water in such a composition, up to 40 vol.% Water can be “dissolved” in the form of a water-in-oil microemulsion. At a higher water content, spontaneous phase reversal occurs with the formation of a finely dispersed oil-in-water microemulsion in water.

Such microemulsions, known as maraflud or micellar systems, have oil-displacing properties and the ability to equalize the injectivity profile of injection wells.

The largest project carried out in the USA by Maraton to pump such a microemulsion into a reservoir at the Illinois oil fields allowed an additional 40,000 m ^{3 of} oil to be produced.

However, the high cost of carrying out these treatments, primarily due to the high costs of expensive surfactants and polar solvent, as well as the low efficiency of these compositions in aligning the injectivity profile of injection wells forced the company to look for more economical and comprehensively effective compositions, i.e. formulations that, along with oil-displacing properties, would have the ability to equalize the injectivity profile of injection wells and limit water production in production wells.

The aim of this invention is to develop a composition for aligning the injectivity profile of injection wells and limiting water inflow in producing wells using affordable and inexpensive components and using standard oilfield equipment for the preparation and application of the proposed composition.

Closest to the proposed composition is a composition for oil production and a method for its preparation, containing, wt.%: Heavy asphalt oil with a density of 900 kg / m ³ and more than 50-70, nonionic surface-active substance (nonionic surfactant) 15-25 and tetrachloride carbon (CCL ₄ ) - solvent regulator that increases the solubility in oil of nonionic surfactants and asphalt-resinous components (Patent RU 2125647 C1, bull. No. 3.1999).

This composition has the properties of "soluble oil", ie It has an ultra-low interfacial tension at the oil-water interface, which determines its ability to spontaneously form stable, finely dispersed emulsions of heavy asphalt-resinous oil in water when mixed with water.

The injection into the reservoir of such an emulsion with a high content of nonionic surfactants and asphalt-resinous oil components not only enhances the oil-displacing properties of the water injected into the formation, but also leads to hydrophobization of the surface of highly permeable, water-saturated sections of the formation with asphalt-resinous oil components, thereby reducing their water filtering performance, at at the same time “improving the flow of oil to these hydrophobized areas from low-permeability oil-saturated sections of the reservoir, as a result of a change (inversion) in the reservoir those capillary pressure at the interface of the oil-water in the desired direction "(P.A.Rebinder -. Surface phenomena in disperse systems, colloid chemistry, because of" Nauka ", M.1978, s.364-366).

The disadvantage of this composition, taken as a prototype, is low waterproofing properties, because when using CCL4 as a solvent-regulator, the asphalt-resinous components of the oil from the colloidal-dispersed state in the oil volume go into the molecular-dissolved state, which reduces the likelihood of formation of hydrophobic barriers from multilayers and colloidal particles of asphalt-resinous oil components, which are known to be in highly permeable sections of the formation the most effective natural waterproofing substances.

In addition, the composition for oil production, taken as a prototype, due to the presence of CCL4 in it, cannot be used in the oil industry due to the introduction in 2000 of a ban on the use of organochlorine compounds in oil production processes.

The proposed composition for leveling the injectivity profile of injection wells and limiting water inflow in production wells contains heavy asphalt resin oil with a density of 900 kg / m ³ or more, nonionic surfactants and a solvent-regulator, where polyglycol ethers of alkyl phenols having better solubility in the oil phase are used as nonionic surfactants than in water - OP-7 (GOST 8433-81) or neonol Af _9-6 (TU 2483-00770576680-93), and “fusel oil” is used as a solvent regulator that increases the solubility of nonionic surfactants in the oil phase, at the next m ratio of components, wt.%:

Indicated oil 60-70 Indicated nonionic surfactants 5-13 Specified Solvent Regulator Rest

“Fusel oil” is a by-product of rectification of crude ethyl alcohol obtained by fermentation of grain, or potato, or molasses, produced according to GOST 17071-91, is a mixture of higher alcohols (isopropyl, iso-butyl, amyl, etc.) with an admixture of vinegar aldehyde and acetic acid.

"Fusel oil" is a clear liquid from light yellow to red-brown in color with a density of 830-840 kg / m ³ , with a distillation temperature of 80 to 120 ° C, does not freeze at -30 ° C, mixes well with water and light petroleum products, it has (Table 1) noticeable surface-active properties, with respect to resins and asphaltenes it exhibits a coagulating effect, i.e. when dissolved in oil, it promotes the transition of asphalt-resinous oil components from a molecularly dissolved to a colloidal-dispersed state, which, in turn, increases their water-insulating properties.

“Fusel oil” is used as a raw material for the production of technical fatty alcohols and has a 20-fold lower cost compared to nonionic surfactants and a 2-fold lower cost.

From the analysis of patent technical literature, the use of “fusel oil” in the compositions for aligning the injectivity profile of injection wells and limiting water inflow in producing wells was not found, which allows us to conclude that the claimed composition meets the criteria of “novelty” and “inventive step”.

The feasibility of using “fusel oil” in the proposed composition is determined by the fact that when “fusel oil” is added to heavy asphalt resin oil, the interfacial tension of the oil at the interface with water begins to decrease and, as follows from the data given in Table 1, with the content of “fusel oil” oils ”in heavy asphalt-resinous oil of 25 wt.% and more interfacial tension, even without the addition of expensive nonionic surfactants, has an ultralow value, i.e. such systems form finely divided oil-in-water microemulsions. However, as filtration studies have shown, such microemulsion systems, without adding a certain amount of oil-soluble nonionic surfactants to them — oil-water-type emulsion stabilizers, because of their low aggregate stability and high adhesion (adhesion) to a solid surface, have little filterability deep into the reservoir .

Therefore, for a system containing 25 wt.% “Fusel oil” in heavy asphalt-resinous oil, studies were carried out on the filtration properties of microemulsions formed by this system when it contained a given amount of oil-soluble nonionic surfactants (OP-7 or neonol Af _9-6 ) and mixing it with water in a volume ratio of 1: 1.

All other things being equal, the filtration properties of the formed microemulsions were evaluated by their filtration rate through a dense white ribbon paper filter (pore size not more than 10 microns).

In a generalized form, the results of these studies are shown in Fig. 1 in the form of curves of (ΣV) - the total volume of the microemulsion that passed through the white ribbon filter for the total filtering time (Στ), depending on the duration (time) of continuous filtering (τ) min

Curve 1 refers to filtering water through a paper filter (blank experiment). Curve 2 refers to filtering through a paper filter a 50% microemulsion formed by mixing in a ratio of 1: 1 volumes of water and a 25% solution of fusel oil in heavy asphalt resin (without the addition of nonionic surfactants), curves 3-6 to filtering 50 % of microemulsions formed by a similar mixing of water and a solution of fusel oil (25 wt.%) and nonionic surfactants in heavy asphalt resin oil: 5.0 wt.% nonionic surfactants (OP-7) - curve 3, 10 wt.% nonionic surfactants (neonol Af _9-6 ) - curve 4, 13 wt.% Nonionic surfactants (OP-7) - curve 5, 25 wt.% Nonionic surfactants (neonol Af _9-6 ) - curve 6.

Curve 7 and curve 8 relate to the filtration of 50% of microemulsions generated by mixing water in a volume ratio of 1: 1 with the prototype composition containing 15 wt.% Nonionic surfactants (OP-10) and 25 wt.% Nonionic surfactants (OP-10), respectively .

If we take the rate of water filtration (curve 1) through the filter for a time τ = 60 min — const for 100%, then for a microemulsion system formed by mixing equal volumes of water and a solution of heavy asphalt-resinous oil with 25 wt.% “Fusel oil” content, the value (ΣV / Στ) for the specified filtering time reaches zero, i.e. after 60 min, the filtration of this system through the pores of the filter ceases, because the pores of the filter turn out to be completely clogged with coagulated asphalt-resinous oil particles, which is clearly visible on the paper filter.

Curve 3 shows that 25 wt.% “Fusel oil” and 5.0 wt.% Nonionic surfactants (OP-7) are added to heavy asphalt resin oil, a composition is formed, when mixed with water, the aggregate stability of the microemulsion increases significantly, its adhesion decreases sharply (sticking) to a solid surface, which is manifested in the ability to filter this microemulsion through a paper filter. The latter is proved by the fact that the filtrate is a microemulsion system with a dispersion close to the original system, and there is no precipitate of asphalt-resinous oil components on the paper filter. However, as it follows from figure 1, the filtration rate of this microemulsion system compared with water is sharply (4 times) reduced, which indicates its certain waterproofing properties.

Given that the volume of pore space in the filter paper is very small, it should be expected that when such a microemulsion system is injected into the pores of the formation at a distance measured by meters, its leveling properties and water-insulating properties will be manifested with even greater efficiency.

Curves 4, 5, and 6, characterizing the effect of an increase in the concentration of nonionic surfactants in the solution, show that if, at 10 wt.% The content of nonionic surfactants, curve 4 (neonol Af _9-6 ) shows the filtration rate of a 50% emulsion as compared to water, is 38%, at 13 wt.% nonionic surfactants - curve 5 (OP-7) - 50%, then at 25 wt.% the content of nonionic surfactants (OP-7) in the composition - curve 6 practically coincides with the course of curves 7 and 8, characterizing the filtering ability of 50% microemulsions formed by the prototype composition containing 15 wt.% and 25 wt.% nonionic surfactants, the filtration rate of which for the specified filtration time composition It is about 85-90%, i.e. approaching the rate of water filtration. Therefore, in the proposed composition, the content of nonionic surfactants of more than 15 wt.% Was considered impractical, and the limit of 5-13 wt.% Was taken as the optimal content of nonionic surfactants in the composition, providing the necessary aggregative stability of microemulsions.

Moreover, if in the proposed composition the content of nonionic surfactants (OP-7 or neonol Af _9-6 ) is taken in the range of 5-10 wt.%, Then such a composition should be used to isolate water inflow in production wells, and if the content of nonionic surfactants in the composition increases to 10-13 wt.% Composition it is advisable to apply to align the profile of the injectivity of injection wells and increase the coverage of the formation by water flooding.

To prove the conformity of the claimed technical solution to the criterion of "industrial applicability", we present the results of experiments to determine the water-insulating and oil-displacing properties of the proposed composition with a nonionic surfactant content of 5.0 wt.% (Experiment 1), 10 wt.% (Experiment 2) and 13 wt.% ( experiment 3) in comparison with the known composition of the prototype, with a nonionic surfactant content of 15 wt.% (experiment 4) and 25.0 wt.% (experiment 5).

Comparative assessment of water shutoff and oil-displacing properties of the analyzed compositions was carried out under laboratory conditions on a bulk pattern inhomogeneous reservoir, wherein the estimation water shutoff properties was performed to the measurement of initial and final water filtration rate through high permeability and low permeability interlayers and oil-displacing properties of the compositions was determined by the change in the oil displacement coefficient b _drawing :

b _stretch = (H _n - H _k): H _n,

where H _n is the initial (before treatment), and N _to is the final (after treatment) oil saturation for the heterogeneous model of the reservoir as a whole (either high permeability or low permeability layers).

As a reservoir model, we used (Fig. 2) two columns 100 cm long with an internal diameter of 2.6 cm, filled with quartz sand with monmorilonite clay for column 1 with a permeability of 1.5 darsi (high permeability interlayer model) and column 2 with a permeability of 0, 15 darcy (low permeability model).

The columns are equipped with a single input system 3 and separate conclusions 4 and 5 from the columns of liquids filtered through them, and with the help of taps 6 and 7, the analyzed stream can be directed simultaneously through two columns or only through one of the columns, while disconnecting the other column.

Before the start of each of the experiments of the reservoir model with a constant pressure drop (0.2 atm) and open taps 6 and 7, the initial water filtration rate was determined as a whole for the heterogeneous reservoir model (column 1 + column 2). Then, with the closed valve 7 and the open valve 6, the initial filtration rate of water for the high permeability layer (column 1) was determined, and with the closed valve 6 and the open valve 7, the initial filtration rate for the low permeability layer (column 2) was determined.

Further, in accordance with STP 0148070-013-91 “Methodology for laboratory studies on the displacement of oil by reagents,” column 1 and column 2 were saturated with anhydrous oil (density 840 kg / m ³ , viscosity 5.1 MPa · s at 20 ° C). In this case, the initial oil saturation of the heterogeneous reservoir model H _n (in relative% of the pore volume) and the distribution of this oil saturation in the high permeability (column 1) and low permeability (column 2) interlayers were recorded.

An oil-saturated heterogeneous reservoir model prepared in this way was subjected to treatment by injection into it of a 50% microemulsion formed with water of one composition or another in a volume equal to 2 pore volumes. After that, the system with shut-off valves 5 and 6 was kept at a pressure of 0.2 atm in a static state for 24 hours. Then, with open cranes 5 and 6, water was pumped through a heterogeneous reservoir model until constant final filtration rates were established as through highly permeable (column 1) and low permeability (column 2) interlayers of a heterogeneous reservoir model. At the same time, for each experiment, the residual oil saturation was determined, as a whole according to the heterogeneous reservoir model, in relate. % of the pore volume, and the distribution of residual oil saturation in highly permeable and low permeability layers.

In a generalized form, the results of these experiments are presented in table 2 and table 3.

As follows from the data of table 2, the injection into a heterogeneous permeability layer of 50% of the microemulsion formed by the proposed composition, when it is mixed with water (experiment 1, the content of nonionic surfactants in the composition of 5.0 wt.%) In a volume equal to two pore volumes, allowed to reduce the initial rate of water filtration as a whole by an inhomogeneous reservoir model by almost 5 times (from 1620 to 350 cm ³ / h), including in highly permeable layers from 1390 to 300 cm ³ / h, i.e. 4.63 times, and for low-permeability layers from 320 to 150 cm ³ / h, i.e. 2.1 times, while the injection of 50% microemulsions formed by the composition of the prototype (experiments 4 and 5) reduces the rate of water filtration as a whole according to the heterogeneous reservoir model from 1590-1640 cm ³ / h to 1050-1110 m ³ / h, i.e. no more than 1.5 times.

Therefore, a 50% oil-in-water microemulsion formed by the proposed composition containing nonionic surfactants (type OP-7 or neonol Af _9-6 no more than 5.0 wt.%) Is an effective tool for the selective isolation of water inflow in mining wells and alignment of the injectivity profile of injection wells.

From a comparison of the data of experiments 2-3, where in the proposed composition the content of nonionic surfactants was increased to 10.0 wt.% (Experiment 2) and up to 13 wt.% (Experiment 3), the water filtration rate in highly permeable interlayers decreased from 1610-1630 to 400 -580 m ³ / h, which also indicates the possibility of using the proposed composition with a given content of nonionic surfactants, both for aligning the injectivity profile of injection wells, and for selective isolation of water inflow in production wells. Furthermore, as it follows from the data of Table 3, which shows the comparable values oil displacement coefficients (b _drawing) for all 5 experiments, the use of the proposed compositions waterflood system oil layers can significantly improve the coefficient of oil displacement developed nonuniform reservoir permeability.

So, if in general for a heterogeneous reservoir model using the proposed composition with a content of 13 wt.% Nonionic surfactants (experiment 3), the coefficient _bout is 0.72, and for a highly permeable interlayer is 0.77, then for a prototype composition with a similar content of nonionic surfactant b _drawing for inhomogeneous formation model is 0.56, and 0.47 for highly permeable seam, i.e. 1.3-1.4 times lower, and for low-permeability layers, the coefficient _bout using the proposed composition (experiments 1-3) exceeds the same coefficient for the composition of the prototype in 1, 2 times.

The following examples illustrate the method of preparing the proposed composition for leveling the injectivity profile of injection wells and the selective isolation of water inflow in production wells.

To prepare the proposed composition, commercial oil was taken as a heavy asphalt-resinous oil (density 940 kg / m ³ , content, wt.%: Asphaltenes 5.7, silica gels 21.3, paraffin 2.7 and water no more than 1.0) , as nonionic surfactants: reagents OP-7 (GOST 8433-81) and neonol AF _9-6 (TU 2483-00770576680-93) - yellowish viscous liquids with a density close to 1000 kg / m ³ , and "fusel oil" ( GOST 17071-91), a low-viscous, light brown liquid with a sharp specific odor, with a density of 830 kg / m ³ (waste from the production of Pervomaisk Distillery, OAO Tatspirtprom).

A schematic diagram of the preparation of the proposed composition using readily available equipment and materials is shown in Fig. 3, where 1 is a horizontal tank with a volume of 6 m ³ , 2 is a centrifugal pump with an adjustable capacity of 100 to 1000 l / min, 3 is a pipeline, 4 is a sampling valve 5 and 6 are gate valves.

As an example, we consider a method of preparing the proposed composition for leveling the injectivity profile of injection wells in an amount of 5.0 tons, containing, wt.%: Heavy asphalt resin oil 62, nonionic surfactants (OP-7) 13, fusel oil 25.

Given the above differences in the density of the components used in the tank 1 with a closed gate valve 5 and 6 were loaded simultaneously (5000 × 0.6): 0.94 = 3192 liters of heavy asphalt resin oil (V ₁ ), (5000 × 0.15): 1 , 0 = 750 kg of OP-7 (V ₂ ) and (5000 × 0.25): 0.83 = 1506 l of fusel oil (V ₃ ). Then, with the shutter 6 closed, the shutter 5 open, turning on pump 2, the contents were mixed in the tank 1 due to dispersion in the pump 2, flow turbulence in the pipeline 3, and the energy of the liquid jet returned by the pump 2 to the tank 1.

Such mixing is performed until at least three times pumping through the pump 2 of the total volume of the prepared composition mixed in the tank 1 (ΣV = V ₁ + V ₂ + V ₃ ), l.

The time (duration) of mixing (t, min) required to fulfill this condition, based on the given performance of the centrifugal pump 2 (Q, l / min) was determined by the formula: τ = (ΣV × 3): Q.

So, for the preparation of 5.0 t (or 5448 l) of the above composition with a pump capacity of 600 l / min, the duration (time) of mixing the system was 27.0 minutes.

In order to make sure that the proposed composition for equalizing the injectivity of injection wells prepared in this way corresponds in its properties to a sample of a similar composition used as a “standard” (prepared from the above components in advance in laboratory conditions), a sample is taken from sampling cock 4 prepared composition, from which by mixing it with fresh water in a volume ratio of 1: 1 prepare 100 ml of a 50% microemulsion and determine the filter time tion of this volume through a white ribbon paper filter.

In parallel with this, the filtration time of 100 ml of a 50% microemulsion prepared from a laboratory sample of the composition used as a “standard” is similarly determined. With the successful preparation of the proposed composition, the time difference between the filtration of 50% microemulsions with a “standard” should not exceed 1-2 minutes.

If the filtration rate of 50% microemulsions of the prepared composition deviates more from the filtration rate of the 50% microemulsion formed by the “reference” composition, an increase in the filtration rate of the 50% emulsion of the prepared composition can be achieved due to a slight increase in the content of the nonionic surfactants in the prepared composition, and a decrease in the filtration rate of this composition can be achieved by a slight increase in the content of “fusel oil” in it. Then, closing the valve 5 and opening the valve 6, pump out from the tank 1 composition to align the injectivity profile of injection wells prepared in this way.

Similarly, from the above components, 5 tons (5479 l) of the proposed composition for the selective isolation of water inflow in producing wells were prepared, containing, wt.%: Heavy asphalt resin oil 70, nonionic surfactants (neonol Af _9-6 ) 5.0, “fusel oil” 25.0. For this, 3723 liters of heavy asphalt resin oil, 250 kg of nonionic surfactants and 1506 liters of fusel oil were loaded into the tank, after which the contents of the tank 1 were continuously mixed according to the scheme shown in Fig. 3 for 30 min. Table 4 shows the data on the composition of laboratory ("reference") samples of the proposed composition and compositions prepared by the proposed method according to the scheme shown in figure 3, as well as such properties of the prepared composition, as its density and filtration time of 100 ml 50% - microemulsion formed during mixing in a ratio of 1: 1 volumes of water and a sample of the composition taken from the sampling cock 4 immediately after completion of the mixing system. For comparison, Table 4 shows similar data for “reference” samples of the composition with the same ratio of components. A satisfactory similarity in the properties of the analyzed compositions proves the "industrial applicability" of the proposed method for preparing the developed composition for leveling the injectivity profile of injection wells and limiting the water inflow in production wells in quantities necessary for its practical implementation.

Table 5 shows the results of field tests of the proposed composition with 13 wt.% The content of nonionic surfactants (OP-7) in the amount of 5 tons, used in the reservoir pressure maintenance system (RPM) to align the injectivity profile of injection wells, and a similar amount of the proposed composition from 5 wt.% the content of nonionic surfactants (neonol Af _9-6 ) to limit water inflow in the producing well.

Field tests were carried out on the multilayer oil reservoir of the Orlyanskoye field (Samara region), the oil-bearing terrigenous reservoirs of which are represented by different-grained sandstones with porosity from 10 to 30%.

This oil field, discovered back in 1959, is in the final stages of development. The development of the field is carried out with the maintenance of reservoir pressure by flooding the oil reservoir. The average injection rate of injection wells in the field is about 100-115 m ³ / day, the water cut of produced products in the reservoir as a whole has reached 98%, the average production rate of the producing well (in oil) ranges from 1.5-3 m ³ / day.

Two injection wells were selected for treatment, the injection rate of which ranged from 180-200 m ³ / day before treatment, i.e. approximately two times higher than the average injection rate of injection wells in the reservoir, and one production well with an average daily production rate of 1.5-2 m ³ for oil and 10-15 m ^{3 for} water.

Before the treatment, injection wells were equipped with magnetic water flow meters of the SVEM type (TU 39-1233-87) and pressure gauges for recording the injectivity and injection pressure of the well before and after treatment. The proposed composition in each of the injection wells was pumped in 100% form without stopping the injection of water into the well from the RPM system using a metering pump at a pressure higher than the pressure of water injection into the well, and the flow rate of the composition was in the range of 3.0-3.5 l / min which ensured at the initial (before treatment) injection rate of injection wells in the volumes indicated in Table 5, the ability to pump a 2.0-2.5% oil-in-water microemulsion spontaneously formed in the well into the formation.

In total, 2.5 tons of the proposed composition with 13 wt.% Nonionic surfactants were pumped into each of the injection wells during continuous operation of the metering pump for 14 hours, which corresponded to about 110-115 m of 2.0-2.5 vol. .% microemulsions of the type "oil in water" and led (Table 5) to a decrease in the injectivity of the treated injection by almost 2 times, i.e. alignment of their injectivity to the average injectivity of injection wells in the field as a whole.

The treatment of the producing well by the proposed composition in order to limit the water content of the products produced in it was carried out in the following sequence. Initially, using the Azinmash 300 A unit (Tu 26-16-33-75) on an idle production well with an open flow line using a filling fluid (oil), the well was displaced into the receiving reservoir in a volume equal to the volume of the well. Further, in the tank of the Azinmash 300 A unit, by mixing for 10-15 minutes equal volumes of the proposed composition with 5.0 wt.% Nonionic surfactants (neonol Af _9-6 ) and water, a 50 vol.% Oil-in-water microemulsion was prepared in it ", which then, with a closed flow line, was pumped through the annulus into the well under pressure not exceeding the pressure of the gyro-fracturing. After 10 m ^{3 of a} 50% microemulsion prepared from 5 tons of the proposed composition was injected into the well, the well was closed and held for 24 hours to complete the coagulation and adsorption processes of asphalt-resinous oil components in the formation, after which the well was put into operation.

From the data given in Table 5, it follows that after the above treatment of the producing well, a day after putting it into operation, the liquid flow rate of the well stabilized at 6.0-8.0 m ³ per day, while the water cut of production decreased from 87 -88 to 50-55%, and oil production rate increased from 1.5-2.0 m ³ per day to 3.0-4.0 m ³ per day, i.e. almost 2 times.

Field tests have shown the high efficiency of the proposed composition for leveling the injectivity profile of injection wells and limiting the flow of production wells.

Table 1 No. p.p. The content of "fusel oil" in oil, wt.% The value of interfacial tension at the border with water (erg / cm ² ) one 0,0 32,5 2 0.5 29.5 3 1,0 25.0 four 2,5 18.0 5 5,0 12.5 6 10.0 6.5 7 15.0 3,5 8 20,0 1,0 9 25.0 0.5 10 30,0 out ^{*) *)} Molecular solution + microemulsion of insoluble higher alcohols

table 2 No. Defined parameters heterogeneous reservoir model (interlayers) Analyzed formulations: Proposed Famous (prototype) Experience 1 Experience 2 Experience 3 Experience 4 Experience 5 The content of nonionic surfactants in the composition, wt.%: 5,0 10.0 13.0 15.0 25.0 Solvent, wt.% 25 25 25 25 25 Oil, wt.% 70 65 62 60 fifty 1. The initial rate of water filtration for a heterogeneous reservoir model, cm ³ / h 1620 1610 1630 1640 1590 1.1 - for highly permeable interlayers, cm ³ / h 1390 1290 1305 1270 1250 1.2 - for low permeability interlayers, cm ³ / h 310 320 315 320 315 2. The initial oil saturation of the heterogeneous reservoir model, (relative%) 57 56 54 56 57 2.1 - for highly permeable interlayers, (rel.%) 74 76 75 76 78 2.2 - for low permeability interlayers (rel.%) 24 24 25 25 24 3. The final rate of water filtration through an inhomogeneous reservoir model after its treatment with one or another composition, cm ³ / h 350 400 580 1110 1050 3.1 - through a highly permeable layer, cm ³ / h 300 350 415 907 915 3.2 - through a low permeability layer, cm ³ / h 120 150 175 280 300 4. Residual oil saturation of the heterogeneous reservoir model, (relative%) 25 twenty fifteen 25 25 4.1 - for highly permeable interlayers, (rel.%) twenty 19 17 35 41 4.2 - for low permeability interlayers, (rel.%) fifteen fifteen fifteen 17 16

Table 3 No. Parameters p.p. comparisons Analyzed formulations: Proposed Famous (prototype) Experience 1 Experience 2 Experience 3 Experience 4 Experience 5 The content of nonionic surfactants in the composition, wt.%: 5,0 10.0 13.0 15.0 25.0 Solvent, wt.% 25 25 25 25 25 Oil, wt.% 70 65 62 60 fifty 1. The ratio of the initial (before treatment) water filtration rates for a heterogeneous reservoir model 4.63 4.03 2.81 1.48 1.51 2. The ratio of water filtration rates for highly permeable interlayers before and after treatment 4.63 3.69 3.14 1.40 1.37 3. The ratio of water filtration rates for low permeability interlayers before and after treatment 2,58 2.13 1.80 1.14 1.05 4 - Coefficient of oil displacement in a heterogeneous reservoir model (b _drawing) 0.56 0.64 0.72 0.55 0.56 - for highly permeable - seam (b _drawing) 0.72 0.75 0.77 0.54 0.47 - for low-permeability - seam (b _drawing) 0.37 0.38 0.40 0.32 0.33

Table 4 Appointment of the composition Try Content, wt.% Sample density Filtration time 100 ml 50% ME, min TN Nonionic surfactants CM Composition for leveling 1. "Standard" 60 13 27 922 67 injection well profile 2. Experimental batch 60 13 27 925 65 Composition for the selective isolation of water production wells 3. "Standard" 60 5 35 916 23 4. Experimental batch 60 5 35 915 21 Designations: ТН - heavy bituminous oil,
Nonionic surfactants - nonionic surfactant,
S / M - "fusel oil",
ME - microemulsion

Table 5 Type of the processed well analyzed parameters The values of the analyzed parameters Before processing After processing 1. Injection well No. 1
- throttle response, m ³ / day 180 95 - discharge pressure, atm 87 87 2. Injection well No. 2
- throttle response, m ³ / day 200 105 - discharge pressure, atm 87 87 3. Production well
- well flow rate, m ³ / day 11.5-17.0 6.0-8.8 - oil flow rate, m ³ / day 1.5-2.0 3.0-4.0 - water cut,% 87-88 50-55

Claims (1)

Composition for leveling the injectivity profile of injection wells and limiting water inflow in producing wells, containing heavy asphalt-resinous oil with a density of 900 kg / m ³ or more, a nonionic surfactant, nonionic surfactants and a solvent-regulator, characterized in that polyglycolic ones are used as nonionic surfactants esters of alkyl phenols with better solubility in the oil phase than in water — OP-7 or neonol Af _9-6 , and “fusel” is used as a solvent regulator to increase the solubility of nonionic surfactants in the oil phase oil ”, in the following ratio of components, wt.%: Indicated oil 60-70 Indicated nonionic surfactants 5-13 Specified Solvent Regulator rest

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