Method of hydrocarbons recovery increasing

FIELD: oil and gas industry.

SUBSTANCE: under method the first device is installed in the horizontal well. Firth fluid is injected in the first horizontal well via the first device. HCs production is ensured from the second horizontal well under the first well. Second fluid is injected to the third well shifted to side from the first and second wells to displace fluids in the reservoir to the second well. At that HC production from the second well is continued. Hydraulic connection is ensured between the first, the second and the third wells. Pressure in the first well is increased using the second fluid injected to the third well. First well is closed when its pressure is increased by the second fluid to pressure sufficient to displace HCs from the second well during HCs production.

EFFECT: increased method efficiency.

29 cl, 10 dwg

 

Background of the INVENTION

The technical field of the invention

Embodiments of the invention, in General, are ways of increasing the extraction of hydrocarbons from an underground reservoir.

Description of the prior art

Oil can, in General, be divided into classes or types according to its viscosity and density. Types of oil having a high viscosity and density, can provide greater complexity for extraction from the reservoir to the surface. In particular, high-viscosity heavy oil requires improved methods of extracting the oil for extraction. In the following description the generic term "oil" includes hydrocarbons, such as extra-heavy oil, but also less viscous grade of oil.

Most of the world's oil potential is heavy or extra-heavy oil in Orinoco Belt in Venezuela, oil Sands in Canada, and in the Ugnu reservoir in Northern Alaska. Currently, some existing oil reservoirs are exploited with the use of improved methods of extraction with the heat treatment or methods using solvents, providing the degree of extraction in the range of 20%-25%. The most common method of heat treatment is the injection of steam into the reservoir, whereby the enthalpy of heat from the vapor is transferred to the oil at con�ensutie. Heating reduces the viscosity of oil, providing gravity drainage and selection. Thus, the extraction of oil is high, if the temperature can be maintained close to the temperature of the injected steam. Well-known methods, such as stimulation of cyclic steam injection ("CSS"), injected into the well to displace (Push) and gravity drainage at the injection of steam ("SAGD"), can be used to extract oil mentioned above of potential reserves.

In the method of stimulating cyclic steam injection using a single vertical borehole. Steam is pumped into the well from promproizvodstva installation on the surface. After conditioning of the collector with steam for a predetermined time, the oil is then extracted from this well. When production is reduced, this process is simply repeated. Additionally, you may need a pump for pumping the heated oil to the surface. In this embodiment, the pump is often extracted, each time injected steam, and then descend to the place of work.

In the way to use the vertical displacement of the well known as well wipe or injection well, and posted with her in terms of neighbouring well known as a production well. Steam is continuously injected into the well forcing out of promproizvodstva installation on the surface d�I heat the oil in the surrounding reservoir. Front perenasysheny then displaces the heated oil in a second borehole for the extraction.

In the way that gravity drainage at the injection of steam use two horizontal wells parallel and arranged one above the other. Top well known as injection well and a lower well known as a production well. Each well may have a shaft with the annular filter. Steam is continuously injected into the upper wellbore to heat the oil in the surrounding reservoir. Steam and the force of gravity, cause the flow of oil and its drainage hole in the bottom. The oil is then lifted out of the bottom of the borehole to the surface.

These methods have many advantages and disadvantages. With the increasing number of potential petroleum reservoirs and complexity of the working conditions in these reservoirs, there is a need to develop more effective and improved methods of oil extraction.

Summary of the INVENTION

The invention relates to a method that combines gravity drainage by steam and the displacement of the extracted oil from the underground reservoir. Implementation option includes the use of downhole promproizvodstva installations or other downhole mixing devices to increase oil production. Additionally, an implementation option includes �you use excess carbon dioxide and oxygen to increase oil recovery.

BRIEF description of the DRAWINGS

For detailed understanding of the above aspects of the invention are given more specific description as summarized above, embodiments of the invention, some of which illustrate the accompanying drawings. It should be noted, however, that in the accompanying drawings show only typical embodiments of this invention, are not considered as limiting its scope as the invention may involve other equivalent effective implementation options.

Fig.1 shows the scheme of work gravity drainage at the injection of steam.

Fig.2 shows a diagram of the displacement.

Fig.3 gives the comparison of the schemes of work gravity drainage at the injection of steam and displacement.

Fig.4 shows the scheme of work gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation.

Fig.5 gives the comparison of the schemes of work gravity drainage at the injection of steam, the displacement of the joint scheme.

Fig.6 compares the action of excess carbon dioxide and oxygen when used in the gravity drainage at the injection of steam/wipe.

Fig.7 compares the action of excess carbon dioxide when used in the scheme of gravitation�th drainage at the injection of steam/wipe/downhole promproizvodstva installation.

Fig.8 a comparison of the action of the mesh density of wells at work gravity drainage at the injection of steam.

Fig.9 a comparison of the action of viscosity of oil in the gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation.

Fig.10 shows a graph of the density relative to the temperature of carbon dioxide.

DETAILED description of the INVENTION

Embodiments of the invention, in General, relate to methods of increasing oil recovery from the reservoir. According to one variant of implementation, provided the scheme of work with the Association of the action of gravity drainage at the injection of steam and displacement using downhole promproizvodstva units ("DHSG") or other downhole mixing devices, excess carbon dioxide and excess oxygen. As proposed in this document, the invention shall be described with reference to downhole paraprotein installations. It should be noted, however, that aspects of the invention are not restricted to using downhole promproizvodstva installations, but is equally applicable for use with other types of downhole mixing devices. To better understand the novelty of the invention and its application, made reference to the accompanying drawings.

Fig.1 shows �Hema 10 work gravity drainage at the injection of steam. Scheme 10 work gravity drainage at the injection of steam is the method used for extraction of oil with low mobility by reducing the viscosity of oil, sufficient for gravity drainage of oil down the sides of the collector 19 to the steam operating the well 13 placed in the bottom of the collector. Scheme 10 work gravity drainage steam injection includes an injection well 11 located above the operating bore 13, each of the wells, including horizontal part of the trajectory. The distance between the horizontal parts of the trajectory of each well can vary within a wide range depending on the conditions of the collector. In one embodiment, the implementation of a range of distances between the injection well 11 gravity drainage at the injection of steam and production bore 13 is from about 26 to about 38 ft (8-12 m). In an alternative embodiment of the range of distances between the wells is from about 15 to about 50 ft (5-15 m). Draining oil 15 obtained according to scheme 10 work gravity drainage at the injection of steam goes into the production well 13. Downhole steam-generating plant 17 (discussed in more detail below) can be placed on the bottom point of the vertical section on�metallinou wells 11. Advantage of the circuit 10 works gravity drainage at the injection of steam, in General, includes accelerated the initial rate of oil production.

As shown in Fig.1, the saturation (Soilcollectors directly surrounding the horizontal portion of the trajectory of the injection well 11, and above the horizontal part of the trajectory production well 13, is in the range from zero to about 9 percent. The saturation gradually increases with increasing distance from the circuit 10 works gravity drainage at the injection of steam; the range includes from about 9 percent in points, the closest to the wells 11 and 13, up to about 75 percent at the points most distant from the wells 11 and 13. Also, the range of oil saturation from about zero to about 30 percent goes further schemes 10 works gravity drainage at the injection of steam in the upper part of the reservoir, relative to the lower part, forming the downward slope of the saturation profile. Gravitational drainage affects the slope of the saturation profile, as draining the oil 15 is directed from the upper position to the lower position, where the production well 13.

Fig.2 shows a diagram 20 mode of displacement. Scheme 20 the mode displacement method is used to create oil increased mobility where couples injected into the reservoir, can go some distance, to form the collector 29 of the steam and to provide oil production by combining gravitational discharge from the collector 29 of steam and water flooding displacement of hot water (formed by the condensation of steam in the reservoir oil toward a production well 25, placed in the lower part of the manifold. Scheme 20 mode of displacement includes displacement or injection well 23, posted in plan with operational bore 25, each well comprising a horizontal part of the trajectory. In an alternative embodiment of the injection well 23 includes only the vertical part of the trajectory. The distance between the wells may vary within wide limits depending on the conditions of the collector. In one embodiment, the implementation of the distance in plan between the injection well 23 displacement and operating bore 25 is less than about 500 feet (153 m). In an alternative embodiment of the range of the distance in plan between the wells is from about 500 to about 700 feet (153-214 m). Downhole steam-generating plant 27 may be located at the bottom of the vertical section of the injection well 23. Advantage of the circuit 20 of the displacement, in General, includes took�increase the ultimate oil production.

As shown in Fig.2, the temperature directly surrounding an injection well 23, is in the range of about 239-262 degrees C, which forms a temperature gradient extending from the horizontal part of the trajectory of the injection well 23 to the horizontal part of the trajectory of the production well 25. The temperature gradient gradually decreases in temperature near the roof and, even faster, near the foot of the bed. Temperature range includes from about 262 degrees closest to an injection well 23 to below about 28 degrees C closest to operating the well 25. The lowest temperature in the reservoir is on the vertical part of the trajectory wells 25, ie. below about 52 degrees C. depending on the well conditions and the temperature of the fluids pumped into the well, the temperature range can pass over and under temperature range 28-262 degrees C.

Downhole steam-generating plant is designed to produce, release and injection of high temperature steam and also other gases such as carbon dioxide and excess oxygen in the well. A burner disposed in a downhole promproizvodstva installation, used for combustion and for heating fluids such as water, supplied to the burner surface. Sabinafarajova installation has the advantage consisting in the production of steam and other gases at the well bottom and not on the surface. This advantage can be shown by the example in which the reservoir contains a permafrost layer between the surface and the oil reservoir, or the reservoir is located under the bottom of the cold ocean water and the hot gases pumped from the surface, melting permafrost and gas hydrates in bottom sediments, causing their expansion and extension of the surrounding formation, and the potential collapse of the drilled wells. If the melting of permafrost or absorption of heat, are not considered, then consider several fluids can be mixed in downhole mixing device, such as a static mixer.

Carbon dioxide may be highly preferred additive to the steam injection into the oil reservoir. High concentrations of carbon dioxide can speed up the initial oil production in the work of gravity and can help to produce oil faster in the gravity drainage at the injection of steam or operations of displacement. Carbon dioxide can also be used for cooling a downhole burner in promproizvodstva installation. Finally, depending on the conditions of the oil reservoir, the carbon dioxide in the liquid state is highly soluble in oil low�of oratory.

Oxygen is also a very preferred ingredient in some schemes of work with heat to improve oil recovery. Excess oxygen can burn any hot residual oil near the downhole promproizvodstva installation and can remove all of the carbon monoxide, which is poorly soluble in oil, to form carbon dioxide, which is more easily soluble in cold oil, and prevent the formation of coke, which can clog the formation. In addition, oxygen can generate additional energy from the combustion of oil in the reservoir and the steam from the water in the collector.

Fig.3 shows a comparison of the initial extraction of oil reserves ("OOIP") between the circuit 30 works gravity drainage at the injection of steam and circuit 35 works of displacement. Scheme 35 the operation of the displacement includes the dressing to 165 feet (50 m) between the injection well of displacement and operating well. The initial rate of oil production under the scheme 30 work gravity drainage at the injection of steam is higher than that in the circuit 35 of the displacement, since oil is hot, has a low viscosity and should move to the short distance between the injection well and production well in comparison with displacement bore and production bore in the circuit 35 works of displacement. The spoil� oil circuit 30 works gravity drainage at the injection of steam more than according to the scheme of the displacement during the first 8-11 years of mining. In this period of time in each scheme of work can be extracted between about 30-40 percent of the initial stocks of oil. Outside the range 8-11 years ultimate oil production scheme 35 the work of displacement is higher than under the scheme 30 work gravity drainage at the injection of steam, as the ultimate extraction scheme 30 work gravity drainage at the injection of steam is limited by the speed of drainage of oil down around the edges of the collector 19 of steam and nearly horizontal fluid flow near the production well 13 under the scheme 30 work gravity drainage at the injection of steam, as shown in Fig.1. After about 15 years, according to the scheme 35 the work of displacement can produce 70-80 percent of the initial oil reserves and 30 work gravity drainage at the injection of steam can produce about 50-60 percent of the initial stocks of oil. For the less viscous oil according to the scheme 30 work gravity drainage at the injection of steam, it is possible initially to produce less oil than under the scheme 35 the work of displacement, due to quickly set a high ratio of steam and oil ("SOR") c more closely spaced injection and production wells. In one embodiment, the implementation of a threshold for the ratio of steam and oil is gradually increasing ratio�of 5:1. Gradually increasing the ratio of steam and oil can be calculated for a specific time period such as a month period of time. Thus, depending on the specific conditions of the collector, may be the preferred Association of two types of works with the use of downhole promproizvodstva plants, as well as carbon dioxide and oxygen.

For a start, should be described one example of the joint work gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation. Section gravity drainage at the injection of steam has a horizontal injection well and a horizontal production well located below the injection well, and the displacement section has a horizontal injection well spaced in terms of borehole gravity drainage at the injection of steam. Joint work can be initiated with the injection of steam into injection well gravity drainage at the injection of steam first face promproizvodstva installation. In an alternate embodiment, the implementation of the joint work can be initiated with the injection of carbon dioxide into an injection well gravity drainage at the injection of steam first face promproizvodstva installation. In an alternative embodiment of the �islord can be injected into an injection well gravity drainage at the injection of steam with steam and/or carbon dioxide. Since carbon dioxide could be quickly produced by the oxidation of oil in the reservoir and the extraction of other gases in the reservoir, it can be used repeatedly and may need a small additional amount of carbon dioxide. Also, recycled carbon dioxide can take a significant amount of natural gas produced from the reservoir, as well as carbon monoxide and hydrogen produced in the reactions in the reservoir. This gas mixture of re-use can be used as fuel for downhole promproizvodstva installation, and the mixture can give a significant amount of energy required for the entire work. Extraction from production wells according to the scheme gravity drainage at the injection of steam can be started after the injection borehole gravity drainage at the injection of steam. After the first predetermined time and the second downhole promproizvodstva installation can be integrated in an injection well of displacement through which vapor is pumped. In an alternative embodiment of the carbon dioxide is pumped into an injection well of displacement. In an alternative embodiment of the carbon dioxide is pumped into an injection well of displacement with steam. The injected carbon dioxide can move ahead front�and thepleasure, created steam, and to reduce the viscosity of oil in the reservoir to heat the oil vapor. Thus, the viscosity of the oil decreases as the heating and dilution. In an alternative embodiment of the oxygen can be injected into an injection well of displacement with steam and/or carbon dioxide. When steam and, if added, carbon dioxide and/or oxygen, from injection wells displacement establishes hydraulic communication with the operational borehole gravity drainage at the injection of steam injection well gravity drainage at the injection of steam, it is possible selectively to close. In one embodiment of the injection well gravity drainage at the injection of steam can be closed when the pressure in the injection well gravity drainage at the injection of steam reaches a specific threshold, such as the initial injection pressure of the injection well gravity drainage at the injection of steam (discussed further below), after the establishment of the fluid from the injection wells of the displacement fluid communication with the operational borehole gravity drainage at the injection of steam. After termination of the injection hole gravity drainage at the injection of steam injection well of vitess�tion can continue to work, while the ratio of steam and oil will not reach a particular threshold, such as gradually increasing the ratio of 5:1. Depending on the conditions of the reservoir, the carbon dioxide can exist in the liquid state, which is vysokochastotnoi in oil over low temperature. When working in this way with the unification of gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation may increase oil production and acceleration of the initial rate of production, higher than in other methods.

Must be described in an alternative implementation, with the unification of gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation. First the fluid may be pumped into an injection well gravity drainage at the injection of steam downhole promproizvodstva installation. Injection well gravity drainage at the injection of steam can get the initial injection pressure. In one embodiment, the implementation of the initial injection pressure of 1500 lb/in2(105 kg/cm2). Production from wells gravity drainage at the injection of steam may begin after the injection borehole gravity drainage at the injection of steam. Production well gravit�gravitational drainage at the injection of steam has a limit on volume and pressure, the volume helps to maintain operating pressure in the operating borehole gravity drainage at the injection of steam. In one embodiment, the implementation of the production well gravity drainage at the injection of steam has a working pressure on the mine, amounting to 800 pounds/inch2(56 kg/cm2). The second fluid may be pumped into the injection well through the mud displacement promproizvodstva installation. Injection well displacement may also receive an initial injection pressure. In one embodiment, the implementation in the injection well of the displacement of the initial injection pressure is 1750 lbs/inch2(123 kg/cm2). With the continuation of production from the production well gravity drainage steam injection bottomhole pressure in the injection well gravity drainage at the injection of steam may be reduced until you reach the limit on working operating pressure in the borehole gravity drainage at the injection of steam. After establishing fluid communication between the injection well of displacement and exploitation borehole gravity drainage steam injection bottomhole pressure in the injection well gravity drainage at the injection of steam may be increased initial pressure for�the entry of the injection wells of displacement, because the volume of fluids produced from a well production gravity drainage at the injection of steam is limited. Injection well gravity drainage at the injection of steam can be selectively closed when the bottomhole pressure in the injection well gravity drainage at the injection of steam is increased again to its initial pressure of injection. In an alternative embodiment of the injection well gravity drainage at the injection of steam can be selectively closed when the bottomhole pressure in the injection well gravity drainage at the injection of steam increases, exceeding its initial injection pressure. In the end, the bottomhole pressure in the injection well of displacement may over time be reduced to limit the operating pressure operating in a borehole gravity drainage at the injection of steam. The first and second fluids may contain vapor, carbon dioxide, oxygen or a combination thereof.

Fig.4 shows one variant of implementation of the scheme work 40 gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation. Scheme 40 of work includes the first circuit 41 of the work gravity drainage at the injection of steam from the injection well 42 located above operation�operating bore 43, the second scheme 45 work gravity drainage at the injection of steam from the discharge bore 46 located above the operating bore 47, and the discharge bore 49 of displacement, located on the side in between the first and second circuits 41 and 45 works gravity drainage at the injection of steam. Each of the wells includes a horizontal part of the trajectory. Downhole steam supply systems 44 similarly installed in the lowest point of the vertical sections of wells 42, 46 and 49. As shown, the oil saturation in the reservoir under the scheme 41 work gravity drainage at the injection of steam to the scheme 45 work gravity drainage at the injection of steam from the discharge bore 49 of displacement, located between them, is less than about 15 percent. Under operational wells 43 and 47 of the saturation is in the range from about 23 percent to about 60 percent. The saturation scheme 40 of work is much lower and comprises an area of greater magnitude compared to a single diagram 10 work gravity drainage at the injection of steam, as shown in Fig.1.

In one embodiment of the method of increasing the extraction of hydrocarbons from an underground reservoir may include two schemes of work gravity drainage at the injection of steam and one op�the radio displacement. Schemes gravity drainage at the injection of steam can be posted in the plan, and each of the schemes of work includes injection well gravity drainage at the injection of steam and a second borehole gravity drainage at the injection of steam. The fluid may be injected into the first injection well gravity drainage at the injection of steam. Hydrocarbon production can begin from the first production well gravity drainage at the injection of steam, which is located under the first injection wells. The second fluid can be injected into a second injection well gravity drainage at the injection of steam. Hydrocarbon production can start from the second production well gravity drainage at the injection of steam, which is located under the second injection wells. Steam can be injected into the borehole displacement, classified in terms of scheme of work gravity drainage at the injection of steam and located between them, continuing the production of hydrocarbons from wells. The injection into the injection well gravity drainage at the injection of steam can be stopped when the steam from the well displacement reaches each of the production wells, respectively. The first and second fluids moghtaderi pairs, carbon dioxide, oxygen, or combinations thereof. Downhole steam supply systems can be located in each injection well gravity drainage at the injection of steam in the wellbore displacement. In an alternative embodiment of the carbon dioxide and/or oxygen may be pumped into the borehole displacement with steam. In an alternative embodiment of the carbon dioxide and/or steam can be generated by the mine (through downhole promproizvodstva installation) in the injection well gravity drainage at the injection of steam and in the well of displacement.

In an alternative embodiment of the method of increasing the extraction of hydrocarbons from an underground reservoir may include pumping the first fluid into the first injection well gravity drainage at the injection of steam through a downhole promproizvodstva installation when you first start pumping pressure. The second fluid can be injected into a second injection well gravity drainage at the injection of steam through a downhole promproizvodstva install the second primary injection pressure. Production from the first and second production wells gravity drainage at the injection of steam can start with the first and second working pressure, respectively. Pressure on �a joy injection wells gravity drainage at the injection of steam can be reduced to the operating pressure of the respective production wells gravity drainage at the injection of steam. The third fluid may be pumped into an injection well of displacement in the third the initial injection pressure. In one embodiment of the implementation, after establishing fluid communication between the injection well of displacement and the first operational borehole gravity drainage steam injection, the first injection well gravity drainage at the injection of steam, it is possible to selectively close when needed no stirring. In alternative implementation, after establishing fluid communication between the injection well of displacement and each of the production wells gravity drainage at the injection of steam, each of the respective injection wells gravity drainage at the injection of steam, it is possible selectively to close. The first or second injection well gravity drainage at the injection of steam can be closed when the pressure at the wellhead in the first or second injection well gravity drainage at the injection of steam is greater than or equal to its initial injection pressure, respectively. First, second and third fluids may contain vapor, carbon dioxide, oxygen or a combination thereof.

Fig.5 shows a comparison of the following: (1) scheme 51 the work of the gravitational trenirovki� in the injection of steam, including an injection well, located above the operating bore, (2) the scheme of 53 works of displacement, including an injection well spaced in the plan to 165 feet (50 m) with an operating bore, (3) circuitry 55 work gravity drainage at the injection of steam/horizontal displacement, which includes the scheme of work gravity drainage at the injection of steam from the injection well, located above the operating well and an injection well of displacement, posted in plan to 165 feet (50 m) from the borehole gravity drainage at the injection of steam, in this case the injection well comprises a horizontal displacement of the trajectory, and (4) scheme 57 work gravity drainage at the injection of steam/vertical displacement, which includes the scheme of work gravity drainage at the injection of steam from the injection well, located above the operating wells, and injection wells ousting posted in plan to 165 feet (50 m) from the borehole gravity drainage at the injection of steam, injection well of displacement contains only the vertical part of the trajectory. Supplied pairs contains 5,65 mole percent carbon dioxide. The figure shows the acceleration from the initial production as for sh�55 we work gravity drainage at the injection of steam/horizontal displacement, and circuit 57 work gravity drainage at the injection of steam/vertical displacement, in the range of about 15-25 percent of the initial production of oil reserves after 3-6 years. The figure also shows that after about 10 years of oil production for circuits 55 and 57 work gravity drainage at the injection of steam/the displacement is twice the loot for the circuit 51 only gravity drainage at the injection of steam, about 75-85 percent of the initial production of oil, compared to 35-45 percent of production initial stocks of oil. The figure further shows that when the scheme 57 work gravity drainage at the injection of steam/vertical displacement oil is extracted faster than under scheme 55 work gravity drainage at the injection of steam/horizontal displacement; the result is obtained, since the pairs of vertical injection wells can quickly reach wells gravity drainage at the injection of steam. In one example, four vertical injection wells eviction may be required for the injection of steam, similar to the one horizontal injection well displacement, thus, the production of a single vertical well can be lower.

Fig.6 shows the effect of excess carbon dioxide and excess oxygen, �reminaing in the scheme of gravity drainage at the injection of steam/wipe, with downhole promproizvodstva installing or without her or with another downhole mixing device. The first is to work scheme 61 gravity drainage at the injection of steam/wipe spacing 330 ft (101 m) between the gravity drainage of steam injection and displacement, including the use of steam only with vacuum insulated pump-compressor pipe to reduce steam condensation. The second scheme is 63 works by gravity drainage at the injection of steam/wipe spacing 330 ft (101 m) between the gravity drainage of steam injection and displacement, including the use of steam and 20 mole percent carbon dioxide with vacuum insulated pump-compressor pipe to reduce steam condensation. The third scheme is 65 work gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation spacing 330 ft (101 m) between the gravity drainage of steam injection and displacement, including the use of steam, 20 mole percent carbon dioxide and 5 mole percent of oxygen. As shown, the third circuit 65 work using downhole promproizvodstva installation, oxygen and carbon dioxide accelerates oil production. Excess carbon dioxide can serve in Kutch�as refrigerant for downhole burner promproizvodstva installation. The second scheme 63 work shows that about 80 percent of the initial oil is extracted, when added to an excess of carbon dioxide with the use of vacuum insulated tubing over a period of 15 years. About 38 percent of the initial oil is extracted in the first scheme 61 work using steam only with vacuum insulated tubing pipe for the same period. In comparison with Fig.5, the third circuit 65 of the work, ie. gravity drainage at the injection of steam/wipe spacing 330 ft (101 m) and 20 mole percent excess of carbon dioxide and 5 mole percent of oxygen, indicates that the oil has been extracted as quickly as in scheme 55 work gravity drainage at the injection of steam/horizontal displacement spacing 165 feet (50 m) and the use of 5,65 mole percent carbon dioxide. Thus, a smaller number of steam injection can be used when capturing excess carbon dioxide and oxygen in downhole promproizvodstva the installation.

Fig.7 shows the effect of excessive carbon dioxide and oxygen in the injection of downhole promproizvodstva plant or other downhole mixing device in the scheme of gravity drainage at the injection of steam/wipe with a spacing of 330 feet (101 m) midproduction drainage at the injection of steam and displacement. The first circuit 71 work includes 5,65 mole percent carbon dioxide, ie. excess oxygen is absent. The second scheme 73 work includes 5,65 mole percent carbon dioxide, 5 mole percent of oxygen in the displacement and 3 molar percent in the gravity drainage at the injection of steam. The third circuit 75 work includes 15,65 mole percent carbon dioxide and 5 mole percent of oxygen. The fourth circuit 77 work includes 25,65 mole percent carbon dioxide and 5 mole percent of oxygen. The fifth circuit 79 work includes 35,65 mole percent carbon dioxide and 5 mole percent of oxygen. As shown, increasing the concentration of carbon dioxide and excess oxygen indicates accelerated oil production. Initial production may be delayed, because the downhole steam-generating plant included in the work with the stoichiometric flame, not containing excess oxygen, but containing carbon monoxide, so that the oxygen is not injected until the oil is heated to a temperature high enough for oxygen consumption. When administered excess carbon dioxide, the delay is reduced and the oil is accelerated. The fifth circuit 79 may be stopped for a few years before the second and first circuits 73 and 71 respectively, due to bystrogasjashchajasja high threshold of the ratio of steam and oil due to the addition of carbon dioxide and excess oxygen level.

In the above examples, it is shown that the extraction scheme with gravity drainage of steam injection/displacement can be accelerated with excess carbon dioxide and oxygen. As a result, the spacing of wells gravity drainage at the injection of steam and wells of displacement can be increased, thus requiring the drilling of fewer wells. Excess carbon dioxide is preferred since it dissolves well in unheated oil. The solubility of carbon dioxide in the oil can be even higher if oil temperature is less than 80 degrees F (27°C) and pressure in the reservoir is maintained above 800 pounds/inch2(56 kg/cm2). Under these conditions carbon dioxide is a dense liquid, soluble in oil, and behaves like a supercritical carbon dioxide at higher pressure and temperature. In addition, excess oxygen is also desirable because it helps to remove carbon oxide and produce carbon dioxide, creates more vapor and prevents the formation of coke.

Fig.8 shows the effect of the spacing between the injection well gravity drainage at the injection of steam and operating well. The first spacing 81 is 22 feet (7 m) between the injection well and operation�operating well. The second spacing 83 is 28 feet (9 m) between the injection well and production well. The third spacing is 85 33 ft (10 m) between the injection well and production well. The fourth spacing 87 is 43 feet (13 m) between the injection well and production well. As shown, the delay of oil production maximum is 2 years in the case where the injection well and a production well spaced on a 43 ft (13 m). This delay decreases with decreasing spacing of the wells, giving the prey within a year from the beginning of operation. According to this example, the optimal spacing between wells is 28 feet (9 m).

Fig.9 shows the effect of viscosity of oil when using schemes of work gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation spacing 330 ft (101 m) between the gravity drainage of steam injection and displacement and spacing of 28 feet (9 m) between the injection well and production well gravity drainage at the injection of steam. First job 91 is carried out with oil, having a viscosity 126000 SP. Second job 93 is carried out with oil, having a viscosity 238000 SP. The third work is carried out with 95 oil having a viscosity 497000 SP. The fourth work is carried out with 97 oil, having a viscosity 893000 SP. As pok�knit, there is a slight difference in production between oil viscosity 126000 JV and 497000 SP. Lower viscosity oil gives a rapid increase in oil production after about the third year of operation, with less than about 10 percent of production initial stocks of oil in the first two to four years to more than about 40 percent of production initial stocks of oil after the fifth year. If the oil has a viscosity 893000 SP, then spacing between all wells may need to be reduced. Conversely, if a lower viscosity oil may have larger spacing between all wells.

Fig.10 shows a graph of the density relative to the temperature of carbon dioxide. Carbon dioxide can be a dense liquid at lower manifold pressures, such as below 1000 lbs/inch2(70 kg/cm2), and temperatures below 88 ° F (31°C). As shown, carbon dioxide can exist in the liquid state 100 in the temperature range below 88 degrees F (31°C) and with a density in the range of about 1.2-0.7 g/cm3. Critical point 110 for carbon dioxide, e. the temperature and pressure at which the carbon dioxide passes into the gaseous state, is about 88 degrees F (31°C) and about 1100 lb/in2(77 kg/cm2). In the gaseous state 115 carbon dioxide can be at about 88 degrees F (31°C) with a density lower� 0.2 g/cm 3. At low viscosity oil, the carbon dioxide may be mixed with oil, although this is not supercritical. When high viscosity oil, carbon dioxide may be more soluble in oil than any other gas, which can improve schemes of work gravity drainage at the injection of steam/wipe/downhole promproizvodstva installation. Liquid carbon dioxide can be quite preferred in colder reservoirs, such as under a layer of permafrost, with temperatures between about 45-80 degrees F (7-27°C), as indicated by a shaded band 120 in Fig.10.

Although the above relates to variants of the invention, other and further embodiments of the invention can be developed without deviating from the basic scope and spirit of the invention and scope of the invention defined by the following claims.

1. A method of extracting hydrocarbons from an underground reservoir, comprising:
the installation of the first device for the first horizontal well;
the injection of the first fluid into a first horizontal well through the first device;
production of hydrocarbons from a second horizontal well, located below the first well;
the injection of the second fluid into the third hole, offset sideways �t each borehole, first and second, to displace fluid in the reservoir to the second bore with the continued production of hydrocarbons from the second well;
establishing fluid communication between first, second and third bores;
the increase in pressure in the first well, a second fluid injected into the third well; and
closing the first bore when the pressure in the first well is increased the second fluid to a pressure sufficient to maintain operation of the displacement for hydrocarbon production from the second well.

2. A method according to claim 1, wherein the first device is a downhole promproizvodstva installation.

3. A method according to claim 1, wherein the first fluid includes steam.

4. A method according to claim 3, wherein the first fluid further comprises one or both, carbon dioxide and oxygen.

5. A method according to claim 1, wherein the second fluid includes steam.

6. A method according to claim 5, in which the second fluid further comprises one or both, carbon dioxide and oxygen.

7. A method according to claim 1, wherein the second fluid is injected into the third well of the second device.

8. A method according to claim 1, further comprising the production of carbon dioxide in the third well of the second device.

9. A method according to claim 8, in which the second device is a downhole promproizvodstva installation�th.

10. A method according to claim 1, further comprising selective termination of the injection into the first well when the second well is hydraulically connected to the third bore, and the close of the first bore when the pressure in the first well reaches the initial pressure injection into the first well to support the work of displacement.

11. A method according to claim 1, further comprising selective termination of the injection into the first well when the second well is hydraulically connected to the third bore, and the close of the first bore when the pressure in the first well is higher than the initial pressure injection into the first well to support the work of displacement.

12. A method according to claim 1, further comprising increasing the pressure in the first well when the second well is hydraulically connected to the third bore.

13. A method according to claim 1, wherein the manifold is located under the zone containing a layer of permafrost.

14. A method of extracting hydrocarbons from an underground reservoir, comprising:
the injection of steam into the first horizontal well;
production of hydrocarbons from a second horizontal well, located below the first well;
the injection of steam, carbon dioxide and oxygen in the third hole, offset laterally from each borehole, first and second, with the continued production of hydrocarbons from the second well; a establishing fluid communication between first, second and third bores;
the increase in pressure in the first wellbore using at least one of the following: steam, carbon dioxide and oxygen, injected into the third well; and
closing the first bore when the pressure in the borehole is increased by at least one of the following: steam, carbon dioxide and oxygen to a pressure sufficient to maintain operation of the displacement for hydrocarbon production from the second well.

15. A method according to claim 14, further comprising selective termination of the injection into the first well when the second well is hydraulically connected to the third bore, and the close of the first bore when the pressure in the first well reaches the initial pressure injection into the first well to support the work of displacement.

16. A method according to claim 14, further comprising selective termination of the injection into the first well when the second well is hydraulically connected to the third bore, and the close of the first bore when the pressure in the first well is higher than the initial pressure injection into the first well to support the work of displacement.

17. A method according to claim 14, in which steam is injected into the first well downhole promproizvodstva installation.

18. A method according to claim 14, in which vapor, carbon dioxide and �islord are injected into the third hole downhole promproizvodstva installation.

19. A method according to claim 14, further comprising the injection of at least one of the following: carbon dioxide and oxygen by injecting steam into the first well.

20. A method according to claim 14, wherein at least one of the following: carbon dioxide and steam is generated in bottom-hole zone of the third well using burning oil in oxygen.

21. A method of extracting hydrocarbons from an underground reservoir, comprising:
the installation of the first device for the first horizontal well;
the injection of the first fluid medium under an initial pressure in the first horizontal well through the first device;
production of hydrocarbons from a second horizontal well, located below the first well;
the installation of the second unit in the third hole, offset laterally from each borehole, first and second;
the injection of the second fluid into the third hole through the second device to displace fluid in the reservoir to the second bore with the continued production of hydrocarbons from the second well;
establishing fluid communication between first, second and third bores;
the increase in pressure in the first well, a second fluid injected into the third well; and
closing the first bore when the pressure in the first well is increased the second fluid medium to the pressure to�sufficient to maintain the displacement for production of hydrocarbons from the second well.

22. A method according to claim 21, in which one or both of the first device and the second device are downhole paropronitsaemye installations.

23. A method according to claim 22, in which the first fluid and the second fluid contain pairs.

24. A method according to claim 23, in which the first fluid further comprises one or both, carbon dioxide and oxygen.

25. A method of extracting hydrocarbons from an underground reservoir, comprising:
installation of downhole promproizvodstva installation in the first horizontal well;
the injection of steam and one or both of carbon dioxide and oxygen, in the first well through the steam generator;
production of hydrocarbons from a second horizontal well, located below the first well;
injection of fluid into the third hole, offset sideways
from each borehole, the first and the second, to displace fluid in the reservoir to the second bore with the continued production of hydrocarbons from the second well;
establishing fluid communication between first, second and third bores;
the increase in pressure in the first well using a fluid injected into the third well; and
closing the first bore when the pressure in the well increases the fluid pumped into the third hole, to a pressure sufficient to maintain operation of the displacement for production �of glendorado from the second well.

26. A method according to claim 25, in which the fluid contains steam.

27. A method according to claim 26, in which the fluid further comprises one or both, carbon dioxide and oxygen.

28. A method according to claim 25, in which fluid is injected into the third well using downhole promproizvodstva installation.

29. A method according to claim 25, further comprising the production of carbon dioxide in the third borehole using a downhole promproizvodstva installation.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: during execution of the thermoshaft method of high viscous oil production including vapour injection in the oil reservoir, and oil extraction via the production wells, according to the invention the lower layer of the oil reservoir is developed by several horizontal wells drilled from the drilling level of the oil reservoir, steam injection in the lower layer of the reservoirs via the underground system of steam supply, at that the horizontal wells are developed under steam cycle mode, and the underground steam supply system of the further horizontal wells are connected after development of the previous and switching of part of the horizontal wells to the production mode.

EFFECT: creation of the method of high viscous oil production ensuring increased extraction coefficient of the crude oil due to uniform heating of the oil reservoir through height at minimum heat losses per oil production.

3 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves installation of oil-well tubing string with well sucker-rod pump in a well. Additionally, the string features a liner with filter, heating cable along external surface from wellhead to the well sucker-rod pump, capillary well pipeline from wellhead to a depth below the well sucker-rod pump, entering inner space of the liner. Well operation involves simultaneous product extraction through oil-well tubing string by the well sucker-rod pump. Electric current runs over the heating cable. Mix of Intat asphaltene, resin and paraffin sediment solvent and Rekod demulsifier is injected via capillary well pipeline. Demulsifier to solvent ratio is (1:18)-(1:22). Cable with maximum heating temperature up to 105°C and maximum power up to 60 kWh is used as the heating cable.

EFFECT: enhanced efficiency of viscous oil emulsion production.

1 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method of high-viscosity oil well development and operation involves landing of tubing string with well pump with power cable to the well, and landing of capillary tube parallel to the power cable and attached to external surface of the tubing string by clamps. Oil or oil-containing reservoir fluid is produced. Chemical reagent is injected to the well from a tank by a metering pump through the capillary tube. Power cable is inserted to the well through cable gland. Power cable and capillary tube are protected against direct contact with internal well surface by protectors. Electric heater with extension unit, well pump with power cable and sleeve with radial hole to which the capillary tube is connected are inserted into the tubing upwards from the bottom at the wellhead. Electric heater extension unit is connected to the power cable of well pump. The tubing is landed to the well so that its shoe is located at least 2 m lower than bottom of high-viscosity oil reservoir, and electric heater is facing perforation interval of the high-viscosity oil reservoir. At the wellhead, power cable is connected to well pump and electric heater control stations and inserted to the well through cable gland. Capillary tube is inserted to the well through sealed side tap of the well X-mas tree. Electric heater is actuated, and a process break is made for 8 hours to heat bottomhole zone of reservoir in the perforation interval and high-viscosity oil heating at the inlet of well pump. After the process break, well pump is launched simultaneously with the metering pump supplying high-viscosity oil flux via the capillary tube through the radial hole in the sleeve to inner space of the tubing above the well pump.

EFFECT: enhanced well yield, reduced load in the well pump.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method of high-viscosity oil or bitumen field development involves construction of two horizontal wells, one above the other, steam injection to the reservoir, reservoir heating by steam pocket formation, steam and hydrocarbon solvent injection to horizontal injector, and product sweeping from horizontal producer. Associated gas is used as hydrocarbon solvent. Steam and associated gas are injected in sequence in cycles. Steam is injected to the reservoir until extracted product viscosity is 3-5 times higher than initial viscosity at the cycle start, associated gas injection is started along with product extraction until extracted product temperature is reduced by 10-25%, then steam and associated gas injection cycles are repeated.

EFFECT: expanded reservoir coverage, higher level of high-viscosity oil and bitumen production along with material and power cost reduction.

1 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method of oil field development by a horizontal and vertical well system using thermal impact involves horizontal and vertical well drilling and equipment, so that vertical well bottom is located below horizontal well bottom at a design vertical distance of 3 to 7 m, formation of heating area by injection of combustible oxidising mixture (COM) and combustion initiator (CI) to ignite and warm-up the inter-well zone up to 100-200°C, depending on COM and CI type, and to establish hydrodynamic connection between wells; horizontal well is switched to liquid production by a pump, with continued supply of COM and CI to the vertical well to maintain burning and warming-up of the field to 250-350°C which is the temperature of independent burning of COM; afterwards, CI supply is stopped, and COM injection continues to maintain and promote burning along the horizontal wellbore. During construction, horizontal well is equipped with a filter with several zones along the horizontal section length. Before pump landing in the horizontal well, a liner with thermocouples installed inside it for temperature monitoring inside the well opposite to filter zones, that allows for serial opening of only one zone during turning and for shutting filter zones from bottomhole to wellhead. Zone adjoining the bottomhole is opened initially. After combustion initiation, if temperature in this zone falls down from the maximum achievable by combustion in the field conditions to 85-95°C, product pumping is stopped, the liner is turned from wellhead to a definite angle ensuring bottomhole zone shutoff and opening of the next zone used for further product extraction by pumping. After temperature in this zone changes from the maximum achievable by combustion in the field conditions to 85-95°C, this zone is closed by a turn of the liner opening the next zone from the bottomhole, and similarly zones are opened and shut in sequence till the last filter zone from the bottomhole.

EFFECT: optimised operation of horizontal well, reduced power cost of its operation, expanded effective coverage of horizontal producer effect, reduced content of gas in the product extracted, enhanced depletion of oil field stock.

1 ex, 3 tbl, 8 dwg

FIELD: oil and gas industry.

SUBSTANCE: as per the method, an oxidiser and fuel is supplied to a gas generator. Fuel is burnt in the gas generator so that there obtained is a flow of hot gases containing carbon dioxide and acting on gas hydrate so that displaced gas is obtained. Displaced gas is collected on the surface. Gas hydrate is dispersed. In order to obtain the flow of hot gases containing carbon dioxide, a system of gas generators is used. This system includes at least one pair of gas generators oriented anti-symmetrically relative to each other so that flows of hot gases leaving them in opposite directions and acting on the gas hydrate simultaneously bring into rotational movement a turbine with a gas hydrate dispersion device installed on the shaft common to it. There is a fan blade device. Its rotation is provided by transportation of displaced gas directed in an upward direction and non-decomposed dispersed gas hydrate. They are subject during transportation to decomposition so that an additional amount of displaced gas is formed.

EFFECT: improving efficiency of gas extraction due to reduction of power, material and financial costs for implementation of a technological process and minimisation of commercial product losses.

12 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the method capital mining operations are carried out on penetration and developing access channels to a productive formation of a deposit. Underground mining and development operations and field operations on the well production of shale oil and gas are performed using multistaged hydraulic fracturing or thermal effect on the formation. A shale oil- and gas-containing deposit is penetrated by vertical shafts. Preparation of the productive formation for hydrocarbon production is carried out by the underground mining and development openings placed below a water-bearing horizon covering the rock above the shale rock of the deposit. Hydrocarbon production is carried out by mining blocks of underground producing wells with horizontal sections protruded in the formation. The producing wells are drilled from underground cells constructed mainly in the mining and development openings. Before complete hydraulic fracturing of the formation small diagnostic hydraulic fracturing of the formation is made in the producing wells of a small diameter, which are drilled mainly from the mining and development openings to the whole thickness of the productive formation transversely to its course. The product of the producing wells is divided in the shaft bottom into shale gas and shale oil. The shale oil is outputted to the surface for further treatment before delivery to consumers. The shale gas is burnt in the boiler of a shaft bottom heat-generating plant to generate water steam or hot water used for the production of electricity or for the purpose of a thermal effect on the productive formation in order to increase intensity and the production rate.

EFFECT: reduced total volume of operations on drilling producing wells while developing shale deposits.

2 cl, 11 dwg

FIELD: oil and gas industry.

SUBSTANCE: method envisages the usage of aqueous solutions of binary mixtures - inorganic or organic nitrate or hydrate of alkali metals, which are injected through individual channels. The method includes the mounting of equipment in wells at the selected area of a deposit. Each well is equipped with devices to control the temperature, pressure and composition of reaction products in a real time mode. Formation areas in vicinity to the well with a volume of at least 20 m3 are heated preliminarily up to a temperature of at least 100°C by injection of at least 2 t of binary mixture reagents. Cyclic heating of the formation area in vicinity to the well with a volume of at least 100 m3 and weight of 250 t is made up to a temperature of at least 140°C due to a reaction of at least 12 t of the binary mixture reagents. At that the first level of explosion safety is ensured by the alternation of injection of saltpetre solution portions, 1 t each, with portions of industrial water of at least 0.05 t each. The second level of explosive safety in the borehole is ensured by the continuous control and monitoring of the reaction process with the temperature limitation in the well bore below the pre-blasting temperature. This temperature is determined against signs of the reaction self-acceleration at recorded charts of time-temperature and time-pressure curves. In case of these signs the injection of a saltpetre decomposition initiator is stopped to the well. Further injection of the saltpetre solution with the weight of at least 10 t is made to the preheated formation. At that the third level of explosive safety is implemented in the reaction process in the formation, which is catalysed by the heat accumulated during the previous cycles. The third level of explosive safety is ensured by a ratio of the weight of the saltpetre injected to the pores and fractures of the formation to the weight of the rock. The ratio is equal mainly to 1 to 20. Low explosive probability, close to zero, is ensured by a mixture of 95 wt % of rock and 5 wt % of saltpetre. The injection of reagents at all cycles is made at continuous temperature control in the reaction zone and pressure and temperature control in the zone near the packer and in the process of the reagents injection for the purpose of timely cessation of the reaction when the parameters of the reaction exceed limits of permitted modes.

EFFECT: improved efficiency of oil production at worked-out deposits with an increased production safety.

4 cl

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil production, particularly, to from underground oil deposits. In compliance with this invention, at least one production well and one injection well can be used. Temperature distribution in the zone between said wells is analysed. In case temperature is distributed between said zones so that minimum temperature makes at least 20°C, maximum temperature does not exceed 320°C, while their difference makes at least 20°C, aqueous gel-forming preparations are injected via injection well that contain one or several chemical components. These preparations after injection in the deposit form gels under the effects of deposit temperature. Said preparations differ in type and/or concentration of chemical components. Chemical components and/or their concentration are selected to make gel-forming temperature and/or geol-forming time of the second and, if required, any other injected portion, differ from portions injected there before.

EFFECT: higher efficiency of oil extraction due to levelling of injectivity.

19 cl, 4 tbl, 7 dwg

FIELD: oil and gas industry.

SUBSTANCE: development method of heavy oil or bitumen mine field with controlled production extraction includes construction of the top injector and bottom producer with horizontal sections placed one above the other, injection of heat carrier through the horizontal injector with bed heating by creation of steam chamber and extraction of the product through the bottom producer. Thermograms of steam chamber are taken, the chamber's warm-up state is analysed for uniform heating and available temperature peaks, and considering the obtained thermograms uniform heating of steam chamber is performed by changing zones of product extraction. Before start-up of extraction with permanent taking of thermograms heat carrier is injected to the below horizontal well until the layer between wells is heated. Thereafter thermograms are taken along horizontal boreholes of both wells with identification of interval with maximum temperature between the wells. Then measurement instruments are removed, heat carrier in injected to the injector and pump is run in to the above interval in the producer, product is produced by the pump till pressure communication is set between the wells. The pump is removed from the producer, a pump with fibre-optical cable is run in to the well in order to control thermogram along the whole length of producer and monitor pump movement to less heated intervals in process of oil or bitumen production.

EFFECT: usage of this method allows increase in oil recovery factor and open flow potential due to even heating of the steam chamber using standard equipment.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves construction of horizontal producers covering the field, and horizontal injectors. Displacement agent is injected through injectors, and products are swept by producers. Horizontal production wells are arranged parallel to each other. Horizontal injector is positioned between horizontal sections parallel to them. Injection starts from bottomhole. When intake capacity of reservoirs is decreased at the bottomhole of horizontal injector to minimum profitable level, non-operating section of horizontal shaft is isolated in series in direction from the bottomhole to the beginning of horizontal injector wellbore. Horizontal producers are drilled in permeable interlayer at 3-6 m distance below the reservoir bottom and at least at 10 m distance above oil-water interface. Horizontal injector is equally spaced from horizontal sections of producers by a design pattern distance. Displacement agent is injected with reservoir pressure rise by 10-20% compared to recovery zone. After time period sufficient to recover and stabilise frontal zone of liquid injected to the reservoir, operation may return to previous intervals. Horizontal sections of producers are broached in two intervals at a distance preventing hydrodynamic connection of the wells. Products are recovered in turns. Production intervals are switched when products reach minimum profitable water cut level.

EFFECT: increased oil recovery due to stabilisation of frontal zone of liquid injected to reservoir, extended application scope of horizontal wells in various field development conditions.

6 dwg, 1 ex

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to the oil-producing industry, in particular to oil field development with flooding. According to the method the displacement agent is injected and oil is withdrawn through the system of injection and production wells. The flooding mode is changed during the development. The displacement agent is injected into the injection well in intensive mode. Using the surface measuring instruments that are a part of an automated process control system the change of extracted oil volume growth depending on the displacement agent injection volume growth until the moment of fast drop of the extracted oil volume is monitored in real time. Then the displacement agent injection volume after which the named drop occurred is recorded. Further injection into the injection well is performed in the volume below this pre-set value.

EFFECT: decrease of labour input of control of oil field flooding process during injection of the displacement agent into injection wells.

1 ex, 6 dwg

FIELD: oil and gas industry.

SUBSTANCE: method provides for use of the production wells. One or several wells are equipped with pump unit with possibility of discharge change. For each production well the deposit or deposits used for production are known. At wellhead of each production well the produced crude oil and oil gas are measured, as well as crude oil watercut is determined. The product wells product is delivered to the gathering header of the wells cluster. The cluster contains one or more injection wells. For each injection well the deposit or deposits used for injection are known. Injectability of the injected water and required injection pressure are determined. Compatibility of the injected water and produced water is studied. Injection is performed upon compatibility of the injected and produced waters. Coordinates of all production and injection wells of the cluster using the same deposits are determined. For each production well time of the produced product lifting is determined from suction of the pump unit to wellhead at maximum discharge. Volume of produced crude oil and oil gas is measured with interval not exceeding half of measured time of fluid lifting for the given well. At wellhead of each well the injected water pressure and its volume are measured. Injected water volume and wellhead pressure are measured with interval not exceeding half of measured time of water supply to the wellhead of each injection well before parker. For each injection well the curve of injected water pressure and volume vs. time is plotted. For each production well using the plotted volume of produced crude oil and oil gas vs. time the relationship with the injected water volume and wellhead pressure is determined, as well as distances to each injection well ensuring injection to the same deposit. For the production wells equipped with pump units with possibility of discharge change such relationships are determined at different discharge. The wells cluster is controlled based on the obtained relationships for all production wells. At that the treated water supply system for injection is made with possibility to change water volume and wellhead pressure for one or more injection wells.

EFFECT: increased efficiency of clusters well control.

2 cl, 1 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: this process comprises measurement of injection well capacity, feed of products of one or several production wells for preliminary water disposal. Measured are density of green oil and gas, green oil water content are measured in the well. Here said products are divided into partially dewatered oil, gas and water. Partially dewatered oil and gas are fed in gathering main. Disposed water is fed into injection well. Compatibility of disposed water with water of seam wherefrom pumping from injection well is made is defined. If threes are compatible, injection well is equipped with the device to create water pressure sufficient for water injection into seam, for example, with electrically-driven rotary pump. Said device allows varying of feed capacity by frequency-controlled drive for said pump. It is set to minimum feed to define the compliance of disposed water quality with the seam geological properties. At poor water quality, it is directed to gathering main or, at sufficient quality, it is forced into injection well. Disposed water amount is defined. Then, device feed capacity is increased either continuously or in stepwise manner to create water pressure. It is increased unless disposed water quality satisfied the seam geological properties.

EFFECT: higher process efficiency.

3 cl, 1 dwg, 1 ex

FIELD: oil-and-gas industry.

SUBSTANCE: this device comprises hollow case with cover that has working fluid feed channels and bottom with discharge channel that features cross-section larger than that of working fluid feed channel for communication case inside with well bottom zone, moving working member that makes with said case the working chambers. Said working member is shaped to truncated ellipse fitted on the case at antifriction bearing and composed of axle with relationship between arms of top and bottom ends equal to 1:2. Aforesaid working member has the channel to communicate working chamber, antifriction bearing with the case bottom discharge channel. Nozzle is arranged under said bottom with communicating discharge channel and radial equal-cross-section area. Total cross-section area of said holes equals that of discharge channel. Cover bottom surface and bottom upper surface are composed of cylinder generatrix to allow displacement of working member top and bottom arms there over and isolation of working chambers.

EFFECT: higher efficiency of stationary pulse injection of fluid.

2 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: method comprises cyclic decrease and increase of pressure in a formation by pumping of water through injection wells and oil withdrawal through production wells. Into the formation through injection wells the mineralised water is pumped periodically in the volume of 0.1-5 of pore volume of the formation and fresh water in the volume of 0.1-5 of pore volume of the formation. The transition to fresh water pumping after mineralised water pumping is performed without gradual decrease in mineralisation. The structure and concentration of salts of the pumped mineralised water are remained at the level of the formation one. The cycle of pumping of waters with different mineralisation is repeated many times. Fresh water is pumped until the moment when decrease of intake capacity of the injection well exceeds the allowable production level - critical drop of reservoir pressure in target impact areas. The mineralised water is pumped until the moment when the injection well sets to initial or close to initial operating mode which depends from the flow rate of the injected liquid and well head pressure.

EFFECT: increase of oil recovery of formations due to increase of their coverage.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: method comprises run in the production well below fluid level of the pipes string with pumps, and with filters installed at pipe ends, product recovery from top production deposit, oil and water separation in the wellbore, water injection to the bottom deposit, oil lifting to surface. Two filters are run to well on separated pipe strings. Filters are pipes with capillary holes with diameter 2 mm max, and density 50 holes/m min. One filter has hydrophobic surface with hydrophobic degree 99% min, the another filter has hydrophilic surface with hydrophilic degree 99% min. Parker is installed above the top deposit to seal the annulus. Filters are made with length not below the bottom deposit roof. Filter with hydrophilic surface is made with large length then the filter with hydrophobic surface such that the parker installed between the production string and filter with hydrophilic surface will be above the bottom deposit roof, and end of the filter with hydrophobic surface will be above this parker. The parker does not permit the fluid from the top deposit flow to the bottom deposit via the annulus. Moving from the top production deposit to the wellbore the fluid enters the annulus, where it is filtered via the capillary holes of the appropriate filters with hydrophobic and hydrophilic coatings separating to oil, that entering via the filter with hydrophobic surface in the pipes string by the pump is lifted to surface, and to water that entering via the filter with hydrophilic surface in the another pipes string by the pump is pumped in the bottom deposit.

EFFECT: increased efficiency of oil and water separation in the wellbore, increased efficiency of waterflooding and increased oil recovery of the deposit.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method comprises run in the production well of the pipes string with filter below liquid level in well, product recovery from top deposit, oil and water separation in the wellbore, water injection to bottom deposit, oil lifting to surface. The filter is pipe in pipe, the internal pipe has hydrophilic surface with hydrophilic degree 99% min, capillary holes with diameter 2 mm min, and density 50 holes/m min. Outside pipe has hydrophobic surface with hydrophilic degree 99% min, capillary holes with diameter 2 mm max, and density 50 holes/m min. Pipes string diameter used for filter run is equal to diameter on internal filter pipe. Internal pipe has length exceeding length of outside pipe. Outside pipe is located not below the top deposit, and internal pipe - not below bottom deposit. Between the casing string and bottom of the outside pipe above the top deposit the parker is installed, ensuring fluid from top deposit ingress directly in space between the internal and outside pipes of the filter. Between the casing string and bottom of the internal pipe above the bottom deposit the parker is installed also, excluding fluid from bottom deposit ingress in space between the internal and outside pipes of the filter. Moving from top production deposit to the wellbore the fluid enters the space between the internal and outside pipes of the filter, where it is filtered via the capillary holes of the appropriate filter pipes with hydrophobic and hydrophilic coatings, separating to oil that entering in the outside pipe and then in annulus by the pump is lifted to surface, and to water that entering in the internal pipe by the pump is pumped in the bottom deposit.

EFFECT: increased efficiency of oil and water separation in the wellbore, increased efficiency of waterflooding and increased oil recovery of the deposit.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: system includes a group pumping station with a pump feeding water line with a pressure sensor, a water discharge line of the pump, a valve manifold, a system of distributing water lines downstream the pump with flow meters, shut-off and control valves, low-permeable injectors with return valves and high-permeable injectors. At that the system operates in a cyclic mode with cycles of pressure increase and decrease in the feeding water line. The high-permeable injectors are equipped with spring-operated flow controllers. At the water line feeding the pump there is a pressure controller bound with a bypass line with a flow controller and automatic gate. This gate is coupled functionally with a cluster controller. It ensures the collection of data from the flow meters and pressure sensor with the analysis of the performed task against pressure injected through the distributing water lines. The automatic gate is made so that at the r signal of the controller it provides the water flow through the bypass line in order to compensate water injection to the low-permeable injectors at the total deficiency in the injection volume to them.

EFFECT: excluding deficiency in the injection volume to the low-permeable injectors and pressure balancing in feeding water lines.

1 dwg, 1 tbl

FIELD: oil and gas industry.

SUBSTANCE: reservoir pressure maintenance system includes a water supply source, pumps, low-pressure water lines connecting the pump of the water supply source to booster pumps of injectors, which wellheads are equipped with shut-off and regulating valves. At that the low-pressure water lines are under maximum permissible pressure that exceeds the maximum permissible pressure at the input of the respective booster pump; the lines are equipped with pressure regulators. These pressure regulators ensure reduction of pressure at the input of the respective booster pump in the operation process up to a value lower that the maximum permissible pressure but not lower that the minimum permissible pressure for this pump. The pressure regulators are operating as downstream pressure controllers during limitation of the injection volume to one or several injectors or during their complete shut-down. The booster pump is designed for the input pressure as per the following formula.

EFFECT: improved reliability of the pumps operation and increase of their life between overhauls.

1 tbl, 1 dwg

FIELD: oil and gas production.

SUBSTANCE: groups of high intake- and low intake-capacity injecting wells are chosen in a single hydrodynamic system and, for each well, oil reservoir properties and permissible degree of pollution of fluid received by high intake-capacity wells are determined. When fluid from low-permeable oil reservoir flows off through high intake-capacity wells, this fluid is cleaned to permissible degree of pollution.

EFFECT: reduced losses in intake capacity of formations and increased time between treatments of wells.

1 dwg

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