RU2778919C1 - Method for the production of high-viscosity oil and thermal gas-chemical composition for its implementation - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: inventions group relates to the oil industry, in particular, to thermal gas chemical treatment of bottomhole and remote formation zones with heavy and high-viscosity oil. Thermogas-chemical composition for the production of high-viscosity oil contains, wt.%: sodium nitrite 27.8; ammonium nitrate 32.2; copper sulfate 0.12; water the rest. In the method for the production of high-viscosity oil, a well is used, which has the first and second open zones on a horizontal or inclined section, and the above-mentioned thermal gas-chemical composition for the production of high-viscosity oil.

EFFECT: increased coverage of the treatment zone, increased oil recovery, no need for equipment for preliminary heating of the reservoir, maintaining the concentration of the injected thermogas chemical composition, the ability to control the quality of mixing of the components of the thermogas chemical composition due to the fact that mixing occurs on the surface before injection into the well.

2 cl, 2 dwg, 2 ex

Description

The invention relates to the oil industry, in particular to a method and composition for thermal gas chemical treatment of bottomhole and remote formation zones with heavy and high-viscosity oil. The method and composition are applicable to horizontal or sloping multifunctional wells that combine the functions of production and injection.

First of all, the invention can be used in conditions of normal and low reservoir temperatures, to reduce the viscosity of oil, it can also be used in conditions of normal and low reservoir pressures, to increase the permeability of the bottomhole and remote zones of the reservoir by creating additional cracks and caverns. In addition to the above, the invention can be used to activate or renew oil wells, the productivity of which is reduced due to paraffin-hydrate and asphaltene-tar deposits that pollute the filtration channels.

Further in the text, the applicant provides a decoding of the terms that are necessary to facilitate an unambiguous understanding of the essence of the claimed materials and to exclude contradictions and / or controversial interpretations when performing an examination on the merits.

Tubing - tubing.

BR is a binary solution consisting of a mixture of aqueous solutions of inorganic salts of sodium nitrite and ammonium nitrate (ammonium nitrate).

IR - initiating solution - an aqueous solution of an initiating reagent.

TS - thermogas-chemical composition.

Light oil - under the specified term in the context of the present description, the applicant understands oil with a density of not more than 0.92 g/cm³.

From the investigated prior art, the applicant identified analogues of the claimed technical solution.

So, inventions are known according to patents of the Russian Federation, which are analogues in relation to the method.

From the level of technology studied by the applicant, an invention was revealed according to the patent of the Russian Federation No. which is wedged out or replaced by unsaturated rock, the well is driven vertically through the oil reservoir, the well is continued under the reservoir and at the required distance from the first intersection, the well is again drilled through the reservoir vertically and in the opposite direction, that is, from the bottom up, the well constructed in this way is cased with a production string , cemented along the entire length of the well and perforated at the intersection of the well with the reservoir, the development of the well is carried out sequentially - at the first stage, the remote zone is developed, and then the near zone of the first intersection of the well with the oil reservoir, the well is completed with two tubing columns x pipes - tubing, the first of which is brought to the bottom of the reservoir in the zone of the second - a distant intersection of the well with the reservoir and packer in the casing string below the reservoir, and the second tubing string is completed with a downhole pump, lowered into the well to the required depth above the reservoir in the zone of its first crossing, the development of the reservoir is carried out by pumping a displacing agent into the reservoir, in particular water, through the first tubing string, and oil is extracted from the reservoir using a downhole pump and the second tubing string.

From the state of the art investigated by the applicant, an invention was revealed according to the patent of the Russian Federation No. in which the horizontal part of the casing string is located directly in the section of the oil reservoir with uniform properties and has a C-shape, where in succession the first and third sections of the casing string have the same length and the required density of perforations and are located parallel to each other, and the second section connects them into a single casing, and the space between the casing of the second section and the formation rock is filled with cement mortar, a string of tubing or coiled tubing pipes is lowered into the well to the boundary of the second and third sections of the casing, and the annulus in this section the boundary zone between the casing string and this string of pipes is sealed with a packer, in the area of the oil reservoir, a plane-parallel filtration of the displacing agent and reservoir oil is organized by pumping the displacing agent into the reservoir using the tubing string or coiled tubing pipes through the perforations of the final - third horizontal section of the casing columns, and oil is extracted from the reservoir through the perforations of the first horizontal section of the casing string using a flow or artificial lift operation of the well, in which the rise of oil to the wellhead is carried out along the annulus - the annular space of the well, moreover, to organize real-time monitoring of the injection of the displacing agent and extraction of reservoir oil, the well in the zones of the first and third sections of the casing string is equipped with pressure and temperature sensors.

An invention is known according to the patent of the Russian Federation No. 2646902 "Method of developing a high-viscosity oil deposit", the essence is a method for developing a high-viscosity oil deposit, which consists in injecting a displacing agent into the reservoir through a horizontal section of a multifunctional well and selecting reservoir oil from a perforated section of the same well, located horizontally and in parallel agent injection zone, characterized in that along the length of the strip-shaped element (PE) of the oil deposit or the selected direction of the reservoir, multifunctional wells are located sequentially one after another so that two more sections of two adjacent wells are located in the formation zone between the agent injection and oil extraction sections of each well multifunctional wells: closer to the well oil recovery area, the neighboring well agent injection area is located on the left side, and closer to the agent injection area of the considered well, the oil recovery area of the second adjacent well is located on the right side along the length of the PE or a chosen direction, and the considered horizontal sections of all wells are located parallel to each other at the same distance from each other and across the length of the strip-like element, and the development of the oil deposit is carried out by dividing the deposit into strip-like elements over its entire area, each of which is developed using a system of multifunctional wells located within the boundaries of the PE according to the above principle.

The well-known inventions described above are combined in that they use multifunctional wells, where two pipes are located side by side in relation to each other in one casing string, one for supplying a displacing agent and/or heat carrier in the form of steam, and the displaced fluid is produced through another pipe.

The disadvantages of the inventions described above according to the patents of the Russian Federation No. 2580330, No. 2594027 and No. 2646902 are:

- high energy consumption for heating superheated steam;

- heat loss during the passage of steam through the wellbore;

- negative impact on the operation of submersible pumps during the passage of steam, which leads to their overheating and failure.

An invention is known according to RF patent No. 2637259 "Thermogas-chemical binary composition and method of application for processing the bottomhole and remote zones of an oil and gas reservoir", which is analogous in relation to the method and in relation to the composition. The essence is a thermal gas-chemical binary composition for treating the bottomhole and remote zones of an oil and gas reservoir containing equimolar solutions of ammonium salts of mineral acids and alkali metal nitrites with an initiating solution, characterized in that aldehyde solutions containing alcohols or acetone are used as an initiating solution, converting aldehyde groups into hemiacetals, which have a reduced reactivity, which provides an induction period sufficient for the safe injection of the initial reagents into the oil and gas reservoir. A method for treating the bottomhole and remote zones of an oil and gas reservoir, including injection into the reservoir of a thermal gas chemical binary composition - solutions of ammonium salts of mineral acids and alkali metal nitrites with an initiating solution, characterized in that the mixing of solutions of ammonium salts of mineral acids and alkali metal nitrites with an initiating solution is carried out in intensive mixing mode before the injection of a thermal gas-chemical binary composition into the oil and gas reservoir, and aldehyde solutions containing alcohols or acetone are used as an initiating solution, converting aldehyde groups into hemiacetals, which have a reduced reactivity, which provides an induction period sufficient for the safe injection of initial reagents into the oil and gas reservoir.

The disadvantage of the known technical solution in relation to the method is that:

production is carried out periodically, first, the injection of a thermal gas chemical binary composition, followed by lifting the tubing and then lowering the pumping equipment, the maximum possible pumping and then stopping and then tripping operations are repeated with the injection of a new portion of the thermal gas chemical binary composition;

there is no possibility to produce high-viscosity oil from inclined and horizontal wells;

it is not possible to change the perforation zone (opened zone) for fluid pumping and binary composition injection without lifting the pump to the surface;

decrease in the concentration of the binary composition as a result of dilution of the BS in the wellbore with water.

The disadvantage of the known technical solution in relation to the composition is that:

- difficult to implement temperature range for the preparation of initiating additives;

- impossibility of application in "cold" formations due to crystallization of the known composition and precipitation.

From the studied level of technology, the article "Numerical modeling of thermal effects in the treatment of wells with solutions of binary mixtures" was revealed [UDK 622.236; 622.276.6, Varavva A. I., Vershinin V. E. © Oil and gas business online publication. 2017. No. 6] [http://ogbus.ru/files/ogbus/issues/6_2017/ogbus_6_2017_p20-34_VaravvaAI_ru.pdf]. The essence is the question of the effectiveness of the method of increasing the productivity of wells when they are treated with aqueous solutions of binary mixtures. After injection of the solution into the formation, an exothermic reaction of interaction between the components of the binary mixture is initiated, accompanied by the release of gases. The impact on the bottomhole zone of oil wells of heated products of a chemical reaction is combined and comes down to three phenomena: heating of the rock and the oil in it; cleaning the bottomhole zone from paraffins, resins and clogging deposits; expansion of the system of natural cracks and the appearance of artificial cracks. As a result of treatment, two areas are formed near the well: increased conductivity and elevated temperature, where the oil viscosity decreases. The sizes of the regions may not match. Each area contributes to the increase in well productivity. In this work, the processes of thermal effects of chemical reaction products on the reservoir are studied by the methods of mathematical and numerical modeling and the increase in well production rate due to a decrease in oil viscosity is estimated. A mathematical model of the reaction process of binary mixture components, their filtration and influence on the reservoir system is proposed. The results of numerical simulation of the reaction process of a binary mixture and subsequent oil production from a heated reservoir are presented. Estimates are obtained for the increase in temperature and size of the heating region during an exothermic chemical reaction in the pore space, as well as the expected increase in oil production and the duration of the effect. The cases of different concentrations of salts of the binary system are investigated. The high economic efficiency of the method is shown in terms of thermal effects of production increment. Known technical solution used by the applicant as a mathematical model for the selection of the formulation of the claimed composition.

The disadvantage of the known technical solution is the use of a high concentration of the binary solution, which can lead to precipitation.

An invention is known according to the patent of the Russian Federation No. 2639003 "Method of producing high-viscosity oil". The essence is a method for producing high-viscosity oil from a well, including equipping a well with a casing pipe with two open zones on a horizontal or inclined section, lowering a lower tubing string with a heat-resistant packer into the casing pipe until it takes a position between the open zones, lowering a submersible pump on the upper tubing string to the first open zone, cyclic injection of the coolant through the lower tubing string and lifting the water-oil emulsion to the surface by a submersible pump, characterized in that before lowering the lower tubing string with a heat-resistant packer, the upper end is attached to the bypass pipe mounted on a submersible pump, and together they are lowered on the upper string of tubing, into which, upon completion of the descent, an additional pipe is inserted with an annular gap, for pumping the coolant into the lower string of tubing, it is delivered through the annular gap and bypass pipe, and the rise of the water-oil emulsion to the surface is carried out through an additional pipe hydraulically connected to the pump discharge.

The disadvantages of the known technical solution is:

- additional energy consumption for heating the coolant due to the fact that when the coolant (steam or hot water) is injected from the surface into the well while moving to the perforation zone (opened zone), the coolant loses its temperature;

- the need to install thermal insulation of the submersible pump from the coolant passing nearby, since the pump needs a heat sink during operation;

- insufficiently heated produced oil settles on the walls of the tubing, while moving to the surface, in the form of paraffin deposits, which over time impede the operation of the pump.

An invention is known according to the patent of the Russian Federation No. 2748098 "Method for the production of high-viscosity oil and a device for its implementation". The essence is a method for the production of high-viscosity oil, which consists in first equipping a well, for which it is cased with a casing pipe having the first and second open zones on a horizontal or inclined section, then lower and upper heat-resistant packers are lowered into the well, interconnected by an injection perforated pipe, connect the lower string, on top of which a coaxially perforated fluid extraction pipe is put on, then a separating heat-resistant packer is installed that limits the annular space, and a support with a built-in adjustable valve is screwed into the perforated fluid extraction pipe, a submersible pump is connected and a bypass pipe is inserted into the support from above, corresponding to length of the submersible pump, a tee is mounted on the free end of the bypass pipe and the discharge of the submersible pump, on the opposite side of which the upper column is screwed on and an additional pipe with a sealing element is inserted with an annular gap up to the tee, at the end of which ry attach a tee; then the annular space between the casing pipe and the upper string is filled with water, in the lower part the water movement is limited by a separating heat-resistant packer and a built-in adjustable valve in the support, then the binary composition is pumped, which is fed through the annular gap, bypass pipe and the lower string to the end section of the casing pipe , then the binary composition through the first opened zone or the second opened zone enters the preheated reservoir and then it is pressed with water, the estimated activation time of the exothermic chemical reaction and the heating time of high-viscosity oil in the reservoir are maintained, then the heated water-oil emulsion with unreacted reaction products flows down through the first the opened zone into the annular space between the lower string and the initial section of the casing pipe, then the heated water-oil emulsion enters through the built-in adjustable valve to the submersible pump intake, the heated water-oil emulsion is pumped out and the surface along an additional pipe; when the flow rate decreases, the pumping is stopped and the binary composition is re-injected into the productive zone of the reservoir along the lower column to increase the fluidity of the oil, then the pumping is carried out and the cycles are repeated. The method according to claim 1, characterized in that the treatment of the productive formation is carried out with an increased distance between the first and second exposed zones, but not more than the distance between the upper heat-resistant packer and the separating heat-resistant packer. A device for implementing the method according to claim 1 and claim 2, consisting of a lower string, a lower heat-resistant packer, an upper heat-resistant packer, a support, a submersible pump, a bypass pipe, a tee, an upper string, an additional pipe, a sealing element, a perforated fluid extraction pipe, a separating heat-resistant packer, an integrated adjustable valve, an injection perforated pipe, while the lower heat-resistant packer is connected to the injection perforated pipe; the injection perforated pipe is connected to the upper heat-resistant packer; the upper heat-resistant packer is connected to the lower string in such a way as to ensure the flow of fluid from the support into the injection perforated pipe; the lower column is connected to the support; the upper heat-resistant packer is connected to the perforated fluid extraction pipe in such a way as to allow the flow of liquid through the hole in the support, in which the built-in adjustable valve is installed; a separating heat-resistant packer is installed on top of the perforated fluid withdrawal pipe; a submersible pump is connected to the built-in adjustable valve, while the submersible pump is connected to the tee on the other side in such a way as to make a connection with the sealing element; while the sealing element is further connected to the additional pipe with the possibility of providing a free passage of the produced fluid to the surface; at the same time, a bypass pipe is installed parallel to the submersible pump, which connects the support to the tee in such a way as to allow liquid flow from the upper column to the lower column.

The disadvantages of the known technical solution in comparison with the claimed technical solution are:

insufficient time from the start of BS injection to the start of the reaction due to the use of a binary composition instead of a thermal gas chemical composition, which entails a smaller coverage of the treatment zone;

reduced oil recovery due to the fact that when the flow rate is reduced, the binary composition is re-injected instead of the thermal gas-chemical composition in the claimed technical solution;

additional energy costs and material costs for the installation of equipment due to the fact that pre-heating of the productive formation is carried out;

reducing the concentration of the injected BS, due to the fact that they are forced through with water, and not with light oil, as in the claimed technical solution;

the impossibility of controlling the quality of mixing of the BS components with the activator due to the fact that the mixing takes place directly in the well during movement along the tubing wellbore.

The technical result of the claimed technical solution is to eliminate the disadvantages of analogues in relation to the method and analogues in relation to the composition, namely:

1 - an increase in the time from the beginning of the injection of the TS to the start of the reaction due to the use of the TS instead of the BS, which entails an increase in the coverage of the treatment zone;

2 - increased oil recovery due to the fact that when the flow rate decreases, the TS is re-injected instead of the BS, which increases the coverage area;

3 - reduction of energy and material costs due to the lack of equipment for preliminary heating of the productive formation;

4 - maintaining the concentration of the injected TS, due to the fact that they are pressed with light oil, and not with water;

5 - easily implemented temperature range for the preparation of the claimed TS;

6 - the possibility of using the claimed TS in "cold" formations due to the absence of TS of crystallization and precipitation;

7 - the ability to control the quality of mixing of the TS components due to the fact that the mixing occurs on the surface before injection into the well.

The essence of the claimed technical solution is a thermal gas chemical composition for the extraction of high-viscosity oil, consisting of, wt. %: sodium nitrite - 27.8, ammonium nitrate - 32.2, copper sulfate - 0.12, water - the rest. A method for the production of high-viscosity oil, which consists in first equipping a well, for which it is cased with a casing pipe having the first and second open zones on a horizontal or inclined section, then lower and upper heat-resistant packers are lowered into the well, interconnected by an injection perforated pipe, the lower string is connected, on top of which a coaxially perforated fluid extraction pipe is put on, then a separating heat-resistant packer is installed that limits the annular space, and a support with a built-in adjustable valve is screwed into the perforated fluid extraction pipe, a submersible pump is connected and a bypass pipe is inserted into the support from above, corresponding to the length of the submersible pump, a tee is mounted on the free end of the bypass pipe and the outlet of the submersible pump, on the opposite side of which the upper column is wound and an additional pipe with a sealing element is inserted with an annular gap up to the tee, at the end of which the tee is fixed; then the annular space between the casing pipe and the upper string is filled with water, in the lower part the water movement is limited by a separating heat-resistant packer and a built-in adjustable valve in the support, then the thermogas-chemical composition is pumped according to claim 1, which is fed through the annular gap, the bypass pipe and the lower string into the end section of the casing pipe, then the thermogas-chemical composition through the first opened zone or the second opened zone enters the reservoir and then it is pressed with light oil, the activation time of the exothermic chemical reaction and the heating time of high-viscosity oil in the reservoir are maintained, then the heated water-oil emulsion with unreacted reaction products flows down through the first open zone into the annular space between the lower string and the initial section of the casing, then the heated water-oil emulsion enters through the built-in adjustable valve to the submersible pump intake, the heated water-oil emulsion is pumped out t to the surface through an additional pipe; when the flow rate decreases, the pumping is stopped and the thermogas-chemical composition is re-injected into the productive zone of the reservoir along the lower column to increase the fluidity of the oil, then the pumping is carried out and the cycles are repeated.

The claimed technical solution is illustrated in Fig. 1, Fig. 2.

On FIG. 1 shows a device on which the claimed method is carried out, where 1 is a casing pipe, 2 is the first opened zone, 3 is the second opened zone, 4 is the lower tubing string, 5n is the lower heat-resistant packer, 5c is the upper heat-resistant packer, 6 is the support, 7 - submersible pump outlet, 8 - bypass pipe, 9 - tee, 10 - upper string, 11 - annulus, 12 - additional pipe, 13 - sealing element, 14 - annulus, 15 - perforated fluid extraction pipe, 16 - separator heat-resistant packer, 17 - specially built-in adjustable valve,

18 - discharge perforated pipe.

On FIG. 2 shows the results of obtaining the claimed thermal gas chemical composition with four repetitions, where:

2a - shows a graph of the dependence of temperature on time, where along the X axis

the time is given (h:mm:ss), the Y-axis shows the temperature, °C.

2b - shows a graph of the dependence of pressure on time, where the X-axis shows the time (h:mm:ss), the Y-axis shows the pressure, atm.

Further, the applicant provides a description of the claimed technical solution.

The claimed group of inventions consists of a method and a thermal gas chemical composition, which are described in more detail below.

The claimed method is carried out on a known device described in RF patent No. 2748098 "Method for the production of high-viscosity oil and a device for its implementation" (Figure 1).

A known device for implementing the claimed method consists of a lower tubing string 4, a lower heat-resistant packer 5n, an upper heat-resistant packer 5b, a support 6, a submersible pump 7, a bypass pipe 8, a tee 9, an upper tubing string 10, an additional pipe 12, a sealing element 13, a perforated pipe for fluid extraction 15, a separating heat-resistant packer 16, a specially built-in adjustable valve 17, an injection perforated pipe 18. All components of the known device are interconnected by assembly operations, for example, by screwing. At the same time, the lower heat-resistant packer 5n is connected to the injection perforated pipe 18; the injection perforated pipe 18 is connected to the upper heat-resistant packer 5c; the packer 5b is connected to the lower tubing string 4 in such a way as to ensure the flow of fluid from the support 6 into the injection perforated pipe 18; the lower column of the tubing 4 is connected to the support 6; the packer 5b is connected to the perforated fluid extraction pipe 15 in such a way as to ensure the flow of fluid through the hole in the support 6, in which a specially built-in adjustable valve 17 is installed; a separating heat-resistant packer 16 is installed on top of the perforated fluid extraction pipe 15; a submersible pump 7 is connected to a special built-in adjustable valve 17, while the submersible pump 7 on the other hand is connected to a tee 9 in such a way as to make a connection with a sealing element 13; while the sealing element 13 is further connected to the additional pipe 12 with the possibility of providing a free passage of the produced fluid to the surface; at the same time, a bypass pipe 8 is installed parallel to the submersible pump 7, which connects the support 6 to the tee 9 in such a way as to ensure the possibility of fluid flow from the upper tubing string 10 to the lower tubing string 4.

Further, the applicant provides a description of the claimed thermal gas chemical composition.

The claimed composition for the implementation of the claimed method for the production of high-viscosity oil consists of:

- an aqueous solution of two inorganic salts (binary solution): sodium nitrite and ammonium nitrate with a total concentration of 60%, where the concentration of sodium nitrite is 27.8 wt.%, ammonium nitrate - 32.2 wt.%;

- an initiating additive representing an aqueous solution of copper sulfate with a specified concentration of 0.12% in relation to the total mass of the vehicle.

Thus, the claimed thermal gas chemical composition consists of, wt.%:

sodium nitrite 27.8

ammonium nitrate 32.2

copper sulfate 0.12

water the rest.

At the same time, the applicant explains that the concentration of copper sulfate is established empirically to ensure the conditions for the implementation of a two-hour delay in the start of the thermogas chemical reaction. It has been established that the implementation of a delay in the thermogas-chemical reaction for a period of about 2 hours is possible at a mass ratio of dry powder of copper sulfate: dry binary sodium nitrite and ammonium nitrate = 1: 500.

The implementation of a delay in the start of a thermal gas chemical reaction is necessary to increase the coverage of the treatment zone, as well as to be able to delay the start of injection to perform additional preparatory work.

Further, the applicant provides information about the used components of the claimed thermal gas chemical composition.

Sodium nitrite is a commercial product, for example, according to GOST 19906-74.

Ammonium nitrate (ammonium nitrate) is a marketable product, according to GOST 2-2013.

Copper sulfate (copper sulfate) is a commercial product, for example, according to

GOST 19347-2014.

Further, the applicant describes a method for preparing the claimed thermal gas chemical composition.

Stage 1. Preparation of the initiating solution.

To register the thermobaric characteristics of the thermogas-chemical composition, its production is carried out in a Parr HP high-pressure reactor, the reaction temperature and pressure are recorded at a frequency of ½ second. The initial pressure in the reactor is set to 50 atm. At the same time, the applicant explains that the initial pressure can be set to any, depending on the given initial reservoir conditions.

In the high pressure reactor is placed 0.12 wt.h. (for example, 0.12 g) dry powder of copper sulfate and 0.6 wt.h. (for example, 0.6 g) distilled water, stir until completely dissolved at a temperature of 20 ° C. Get 0.72 wt.h. (for example, 0.72 g) initiating solution.

Stage 2. Preparation of a binary solution.

Take 27.8 wt.h. (for example, 27.8 g) ammonium nitrate, dissolved in 40 wt.h. (for example, in 40 g) distilled water at a temperature of 20 ° C. The dissolution of ammonium nitrate occurs with decreasing temperature.

Next, 32.2 parts by weight are added to the cooled ammonium nitrate solution. (for example, 32.2 g) sodium nitrite and stirred until completely dissolved.

Get 100 wt.h. (for example, 100 g) binary solution.

Stage 3. Preparation of thermogas-chemical composition.

To 100 wt.h. (for example, 100 g) of the cooled binary mixture obtained in step 2, add 0.72 wt.h. (for example, 0.72 g) of the initiating solution obtained in step 1 is stirred until a homogeneous solution is obtained.

At the same time, thermobaric characteristics are recorded - time, temperature and pressure. Registration of thermobaric characteristics is carried out until the beginning of a steady decline in temperature and pressure, after the so-called "peak" of the reaction - a characteristic rapidly growing rise in temperature and pressure. As the “peak” of the reaction passes, a decrease in the values of thermobaric characteristics is observed.

Get the claimed thermogas chemical composition.

The results of experiments with the claimed thermogas chemical composition with four repetitions are shown in the graphs in Fig.2.

From the data shown in graph 2a, it can be seen that the maximum value of the temperature of the thermogas chemical reaction is reached (the smallest value of the delay in the start of the reaction) after 1 hour 58 minutes. The longest time was 2 hours 33 minutes.

From the data shown in graph 2b, it can be seen that the maximum value of the pressure of the thermogas chemical reaction is reached (the smallest value of the delay in the start of the reaction) after 1 hour 58 minutes. The longest time was 2 hours 33 minutes.

Next, the applicant provides a description of the claimed method (Figure 1).

First, a device is assembled for implementing the claimed method similarly to that described in RF patent No. 2748098 "Method of producing high-viscosity oil and a device for its implementation", namely: the well is cased with a casing pipe 1, which has the first and second open zones 2 and 3, respectively, on a horizontal or inclined section , then the lower 5n and upper 5v heat-resistant packers are lowered into the well, interconnected by an injection perforated pipe 18, the lower tubing string 4 is connected, on top of which a coaxially perforated fluid selection pipe 15 is put on, then a separating heat-resistant packer 16 is installed, limiting the annular space 14, and support 6 with a specially built-in adjustable valve 17 is screwed into the perforated fluid extraction pipe 15, the submersible pump 7 is connected and a bypass pipe 8 is inserted from above into the support 6, corresponding to the length of the submersible pump, a tee 9 is mounted on the free end of the bypass pipe 8 and the outlet of the submersible pump 7, with prot On the opposite side of which the upper tubing string 10 is screwed on and up to the tee 9, an additional pipe 12 with a sealing element 13 is inserted with the annular gap 11, at the end of which the tee 9 is attached.

Upon completion of the installation of the device and the operation of heat-resistant packers 5n, 5v and 16, uniting the annular space between the first and second opened zones 2 and 3, two hydraulic lines appear in the well. One line passes through the annular gap 11 between the additional pipe 12 and the upper tubing string 10, the bypass pipe 8 and the lower tubing string 4, ends with an injection perforated pipe 18 with a packer 5n at the end and exits to the second opened zone 3. Another line connects the first opened zone 2 annulus 14 between the lower tubing string 4, the perforated fluid extraction pipe 15 and the casing pipe 1 through a specially designed adjustable valve 17 and a submersible pump 7 with an additional pipe 12 going to the surface.

Further, the annular space between the casing pipe 1 and the upper tubing string 10 is filled with technical or formation water, in the lower part the water movement is limited by a separating heat-resistant packer 16 and a specially built-in adjustable valve 17 in the support 6, which is necessary for cooling the motor of the submersible pump 7 when working with hot water. water-oil emulsion and to control the growth of pressure in the well.

Next, injection or cyclic injection is performed from the surface of the claimed thermogas-chemical composition (TS) (arrows with an unfilled tip in Fig.1), which (TS) is fed through the annular gap 11, the bypass pipe 8 and the lower string of the tubing 4 into the end section of the casing pipe 1 TS through the open zone 2 or 3 enters the reservoir and then it is pressed with light oil, the estimated activation time of the exothermic chemical reaction and the heating time of high-viscosity oil in the reservoir are maintained.

The heated water-oil emulsion with unreacted reaction products flows through the first open zone 2 (arrows with a filled tip) into the annulus 14 between the lower tubing string 4 and the initial section of the casing 1. The heated water-oil emulsion enters through a specially built-in adjustable valve 17 to receive the submersible pump 7 and is pumped to the surface through an additional pipe 12. With a decrease in the flow rate, the pumping is stopped and the TS is pumped back into the productive zone of the reservoir through the lower string of the tubing 4 to increase the fluidity of the oil. This is followed by pumping and the cycles are repeated.

According to the applicant, the injection of "cold" (ambient temperature on the surface) TS solves the problem of heat loss during its transportation to the bottomhole formation zone. The thermogas-chemical composition, consisting of a binary solution and an initiating solution, is injected without further catalyst injection, while the initiating solution, after 2 hours from the moment of mixing with the binary solution, activates the reaction, during which heat is released (200 - 350 ° C) and pressure increases up to 50-100 atm. Next, a small calculated amount of light oil is injected to flush the tubing wellbore. The injection of a thermogas-chemical composition with a calculated time for the start of a chemical reaction proceeds with the release of a large amount of heat and gaseous reaction products, which easily penetrate into the reservoir and heat up high-viscosity oil, making it lighter. It is known that 1 kg of a binary composition (sodium nitrite and ammonium nitrate) in terms of dry matter forms 2,241 kJ of heat [UDK 622.276.65, Mikhailov A.V., Pchela K.V. Exposure Oil Gas. 2020. №6. pp. 56-61.] [https://cyberleninka.ru/perspektivy-razrabotki-tehnologii-termohimicheskogo-vozdeystviya-na-prizaboynuyu-zonu-plasta-skvazhin-dlya-intensifikatsii-dobychi/viewer]. Heated high-viscosity oil flows into the area of perforations, due to the pressure difference, a specially built-in adjustable valve is triggered, opening the fluid passage to the pump filter, and then the fluid rises to the earth's surface by submersible pumping equipment located in the lower part of the tubing string. Oil heated to 200-350 °C does not have time to cool down to the paraffin precipitation temperature and thereby facilitates the operation of submersible pumping equipment and transportation to the finished product collection tank. The technical or reservoir water flooded from the outer surface of the submersible pump solves the problem of heat removal from the engine surface and does not require expensive thermal insulation.

If necessary, water for cooling can be circulated and supplied from the surface through the power supply cable to the installation of an electric centrifugal pump (ECP) with an additional impulse tube manufactured by, for example, Inkomp-Neft LLC.

Further, the applicant provides examples of the implementation of the claimed technical solution (Figure 1).

Example 1. Treatment of a productive formation with a limited distance between the first and second exposed zones.

The well is cased with a casing pipe 1, which has open zones 2 and 3 (the first and second, but may be more) on a horizontal or inclined section. Then the lower injection perforated string 18 with the lower heat-resistant packer 5n at the end is lowered into the well, then the upper packer 5b is hung, then the lower tubing string 4 is connected (the length is chosen depending on the distance to the (extreme) second opening zone 3 on the casing pipe 1). A coaxially perforated fluid extraction pipe 15 of a larger diameter is put on top of the tubing 4, a separating heat-resistant packer 16 is installed on top. 8, corresponding to the length of the submersible pump, and continue to descend into the well. A tee 9 is mounted on the free end of the bypass pipe 8 and the discharge of the submersible pump 7, on the opposite side of which the upper tubing string 10 is screwed on and the assembled unit is lowered into the well. The descent is completed when the lower heat-resistant packer 5n installed on the injection perforated string 18 reaches a position behind the last second opening zone 3 in the casing 1, while the submersible pump 7 is on a horizontal or inclined section of the well. At the end of the descent into the upper tubing string 10 to the tee 9, an additional pipe 12 is introduced with an annular gap 11 with sealing elements 13 at the end, which is hydraulically connected to the outlet of the submersible pump 7. Due to the placement of the additional pipe 12 inside the upper tubing string 10, damage to both pipes is prevented, as well as the power cable of the pump 7. A specially built-in adjustable valve 17 protects the submersible pump 7 and the bypass pipe 8 from a sharp pressure surge resulting from a thermobaric chemical reaction with the release of a large amount of reaction products in the form of gases, which opens after pressure equalization with the reservoir and heat transfer reaction products of the bottomhole zone and the reservoir.

Upon completion of installation and operation of heat-resistant packers 5n, 5v and 16, uniting the annular space between the first and second opened zones 2 and 3, two hydraulic lines appear in the well. One line passes through the annulus 11 between the additional pipe 12 and the upper tubing string 10, the bypass pipe 8, the lower tubing string 4 and the injection perforated pipe 18. pipe 1 through a submersible pump 7 with an additional pipe 12 going to the surface.

Next, the annular space between the casing pipe 1 and the upper tubing string 10 is filled with technical or formation water, in the lower part the water movement is limited by a separating heat-resistant packer 16, this is necessary to cool the motor of the submersible pump 7 when working with a hot oil-water emulsion and to control the pressure increase in the well .

Then, along the annular gap 11, pumping or cyclic injection from the surface of the thermogas-chemical composition (arrows with an unfilled tip) is carried out, which is fed through the bypass pipe 8, the lower string of the tubing 4 and the injection perforated pipe 18 to the end section of the casing pipe 1 with the opened first and second zones perforation 2 and 3. TS through the first or second open zone 2 or 3 enters the reservoir and then it is pressed with light oil, the estimated activation time of the exothermic chemical reaction and the heating time of high-viscosity oil in the reservoir are maintained. The heated water-oil emulsion with unreacted reaction products flows through the open zone 2 (arrows with a filled tip) into the annulus 14 between the lower tubing string 4, the injection perforated pipe 18 and the initial section of the casing pipe 1. The heated water-oil emulsion enters through a specially built-in adjustable valve 17 on the submersible pump 7 is received and pumped to the surface through an additional pipe 12. When the flow rate decreases, the pumping is stopped and the vehicle is pumped back into the productive zone of the reservoir through the lower tubing string 4 to increase the fluidity of the oil. This is followed by pumping and the cycles are repeated.

Example 2: Treatment of a productive formation with increased distance between the first and second exposed zones.

The processing of a productive formation with an increased distance between the first and second opened zones 2 and 3, but not more than the distance between packers 5c and 16, is carried out in the following way: friend. Then, an injection perforated pipe 18 is lowered into the well with a lower heat-resistant packer 5n at the end and an upper heat-resistant packer 5v at the end of the opening zone 3. The length of the lower tubing string 4 is selected depending on the distance to the extreme opening zone 3 on the casing pipe 1. Over the tubing 4 on a distance slightly greater than the opened zone 3, a coaxially perforated fluid extraction pipe 15 of a larger diameter is put on, a separating heat-resistant packer 16 is installed on top. 6 bypass pipe 8, corresponding to the length of the submersible pump, and continue to descend into the well. A tee 9 is mounted on the free end of the bypass pipe 8 and the discharge of the submersible pump 7, on the opposite side of which the upper tubing string 10 is screwed on and the assembled unit is lowered into the well. The descent is completed when the heat-resistant packer 5c installed on the lower tubing string 4 reaches a position behind the last opening zone 3 in the casing 1, and the heat-resistant packer 16 is above the opened zone 3, but below the opened zone 2, while the submersible pump 7 is in a horizontal section wells. At the end of the descent into the upper tubing string 10 to the tee 9, an additional pipe 12 is introduced with an annular gap 11 with sealing elements 13 at the end, which is hydraulically connected to the outlet of the submersible pump 7. Due to the placement of the additional pipe 12 inside the upper tubing string 10, damage to both pipes is prevented, as well as cable.

Upon completion of installation and operation of heat-resistant packers 5n, 5v and 16, dividing the annular space between the opened zones 2 and 3, two hydraulic lines appear in the well. One line passes through the annulus 11 between the additional pipe 12 and the upper tubing string 10, the bypass pipe 8 and the lower tubing string 4. The other line connects the annulus 14 between the lower tubing string 4, perforated tubing string 15 and the casing pipe 1 through a submersible pump 7 with additional pipe 12, facing the surface.

Next, the annular space between the casing pipe 1 and the upper tubing string 10 is filled with water, in the lower part the water movement is limited by a heat-resistant packer 16, this is necessary to cool the pump when working with a hot oil-water emulsion and to control the pressure increase in the well.

Next, pumping is carried out from the surface of the TS (arrows with an unpainted tip), which is fed through the annular gap 11, the bypass pipe 8 and the lower string of the tubing 4 into the end section of the casing pipe 1. The coolant through the second opened zone 3 enters the productive formation and then it is forced through the water light oil solution, withstand the activation time of the exothermic chemical reaction and the heating time of high-viscosity oil in the reservoir. The heated water-oil emulsion with unreacted reaction products flows through the second open zone 3 (arrows with a shaded tip) into the annulus 13 between the lower tubing string 4 and the initial section of the casing 1. The heated water-oil emulsion enters through the valve 17 to the intake of the submersible pump 7 and is pumped out to surface through an additional pipe 12. When the flow rate decreases, the pumping is stopped and the TR is re-injected into the productive zone of the reservoir through the lower string of the tubing 4 to increase the fluidity of the oil. This is followed by pumping and the cycles are repeated.

When the flow rate drops below profitability, the pumping is stopped, the string is raised to the first opened zone 2 and all operations are repeated again, similarly to the treatment of the second opened zone 3, BR with an initiating solution is pumped into the productive zone of the formation along the lower tubing string 4 to increase the fluidity of oil. This is followed by evacuation by pump 7 and the cycles are repeated. When the flow rate drops below profitability, pumping is stopped, the string is raised to the next opened zone, and so on, until all open zones are processed.

Thus, from the above, we can conclude that the applicant has achieved the claimed technical result, namely:

1 - increased time from the beginning of the injection of the TS to the start of the reaction due to the use of the TS instead of the BS to 2 hours or more, which entails an increase in the coverage of the treatment area;

2 - increased oil recovery due to the fact that when the flow rate decreases, the TS is re-injected instead of the BS, which increased the coverage area;

3 - energy costs and material costs are reduced due to the absence of the need to install equipment for preliminary heating of the productive formation;

4 - the concentration of the injected TS is maintained, due to the fact that it is pressed with light oil, and not with water, that is, there is no dilution of the TS;

5 - easily realized temperature range for the preparation of the claimed TS;

6 - the possibility of using the claimed TS in "cold" formations due to the absence of TS of crystallization and precipitation;

7 - the ability to control the quality of mixing of the TS components due to the fact that the mixing occurs on the surface before injection into the well.

The claimed technical solution meets the "novelty" criterion for inventions, since the applicant has not identified technical solutions with the declared set of essential features from the studied state of the art.

The claimed technical solution meets the "inventive step" criterion for inventions, since no technical solutions have been identified that have features that coincide with the distinctive features of the claimed invention, and the influence of the distinctive features on the claimed technical result has not been established.

The claimed technical solution meets the criterion of "industrial applicability" for inventions, as it can be manufactured on standard equipment using known materials and parts.

Claims (3)

1. Thermogas-chemical composition for the production of high-viscosity oil, consisting of, wt.%: sodium nitrite
ammonium nitrate
copper sulfate
water 27.8
32.2
0.12
rest 2. A method for the production of high-viscosity oil, which consists in first equipping a well, for which it is cased with a casing pipe having the first and second open zones on a horizontal or inclined section, then lower and upper heat-resistant packers are lowered into the well, interconnected by an injection perforated pipe, connect the lower string, on top of which a coaxially perforated fluid extraction pipe is put on, then a separating heat-resistant packer is installed that limits the annular space, and a support with a built-in adjustable valve is screwed into the perforated fluid extraction pipe, a submersible pump is connected and a bypass pipe is inserted into the support from above, corresponding to length of the submersible pump, a tee is mounted on the free end of the bypass pipe and the outlet of the submersible pump, on the opposite side of which the upper column is wound and an additional pipe with a sealing element is inserted with an annular gap up to the tee, at the end of which a troy is fixed Nick; then the annular space between the casing pipe and the upper string is filled with water, in the lower part the water movement is limited by a separating heat-resistant packer and a built-in adjustable valve in the support, then the thermogas-chemical composition is pumped according to claim 1, which is fed through the annular gap, the bypass pipe and the lower string into the end section of the casing pipe, then the thermogas-chemical composition enters the reservoir through the first opened zone or the second opened zone and then it is pressed with light oil, the activation time of the exothermic chemical reaction and the heating time of high-viscosity oil in the reservoir are maintained, then the heated water-oil emulsion with unreacted reaction products flows down through the first open zone into the annular space between the lower string and the initial section of the casing, then the heated water-oil emulsion enters through the built-in adjustable valve to the submersible pump intake, the heated water-oil emulsion is pumped out t to the surface through an additional pipe; when the flow rate decreases, the pumping is stopped and the thermogas-chemical composition is re-injected into the productive zone of the reservoir along the lower column to increase the fluidity of the oil, then the pumping is carried out and the cycles are repeated.

Images