WO2012023881A1

WO2012023881A1 - Method and device for producing energy from petrothermal sources

Info

Publication number: WO2012023881A1
Application number: PCT/RU2011/000621
Authority: WO
Inventors: Вячеслав Васильевич ТРУШКИН
Original assignee: Trushkin Viacheslav Vasilievich
Priority date: 2010-08-17
Filing date: 2011-08-16
Publication date: 2012-02-23
Also published as: CH703613A1

Abstract

The group of inventions relates to the field of energy production and, more specifically, to the production of energy from geothermal sources, in particular, renewable sources of petrothermal resources, namely hard hot dry rock (HDR) from the earth's interior, and makes it possible to increase the volume of electrical and/or thermal energy produced while at the same time reducing production outlay. For this purpose, it is proposed to drill a deep well (1) from the earth's surface (4) at least until entry into a hot dry rock formation (5) and to create a petrothermal circulation system at the bottom (3) of the well (1) by boring at least one lateral hole (8) from the well (1) in the hot dry rock formation (5).

Description

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METHOD FOR PRODUCING ENERGY FROM PETROTHERMAL SOURCES AND DEVICE FOR ITS IMPLEMENTATION

Technical field

The group of inventions relates to the field of energy, namely, to obtain energy from geothermal sources, in particular, from renewable sources of petrothermal resources - solid “dry” hot rocks of the earth's interior.

The intensive extraction and use of non-renewable natural energy resources, such as oil, coal, natural gas, etc., gradually leads to their shortage.

An alternative source of energy is the heat of the Earth. The resources of internal heat - geothermal sources - are divided into hydrogeological (hydrothermal) and petrographic (petrothermal). Hydrogeological sources are represented by such coolants as hot groundwater, steam and steam-water mixtures. Petrographic - store the energy of red-hot dry rocks of the earth's crust. While hydrogeological sources are located unevenly in zones of volcanic activity, and, as a rule, are removed from the consumer, petrographic sources are distributed everywhere in close proximity to the consumer, while the petrographic reserves of the internal dry heat of the earth's interior are huge.

State of the art

Obtaining energy from petrothermal sources is possible almost anywhere in the world by drilling deep wells reaching hot dry rock formations (HDR - Hot Dry Rock), supplying coolant to them and removing the heated coolant to the earth's surface, where it is utilized by conversion into heat or electrical energy, while the heat carrier that has transferred heat can be re-fed into a deep well, thereby achieving the creation of a circulation system (closed loop).

Numerous methods are known for generating energy from petrothermal sources, as well as devices for their implementation.

So, according to the technical solution (DE 102005044352 B4, Е21В 43/1 16, F24J 3/08, 2007), in order to master rock formations with a temperature above 100 ° C using HDR heat exchangers, drilling of wells with a depth of 4000-6000 meters is required. To do this, first drill the first deep well to such a hot formation rocks through which water is pumped under high pressure so that cracks form in the formation. Then explosive material is pumped into these cracks and set on fire, so that as a result of detonation, the cracks expand. After that, at least one more well is drilled in the cracking zone of the rock, through which the water heated in the HDR heat exchanger enters the surface of the earth, where in the heat exchanger it transfers its heat, which is used to produce energy, and is sent to the accumulator, this cooled water is again sent to the first deep well.

The disadvantages of this method are the difficulty of creating a circulation system, as well as the high cost due to the need to drill two or more deep wells. In addition, the temperature of the hot rock formations at a well depth of 4000-6000 meters may not be enough to produce thermal and / or electrical energy.

A known method of using the heat of the earth and the extraction of minerals in the zone of weakened earth's crust to produce hot steam in hot dry rocks (RU 2068530 CI, F24J 3/08, 1996), according to which in the zone of weakened earth's crust at a depth of 13 to 30 km continental lithosphere, in which the shear strength of the rocks compared with the pressure applied from above suddenly decreases sharply, water is pumped into a well reaching to the zone of weakened earth's crust, made by fusion drilling and lined with steel pipes, while creating the water pressure that is obtained by the “hydra frack” for splitting a sufficiently large heating zone in hot rock with reduced shear strength, and the injected water after absorbing heat in the split rock is fed through at least one additional well located on the Earth’s surface at a distance of about 100 m from the first well, also performed by fusion drilling and acting as a transport shaft for supplying the medium to the Earth’s surface, where its heat is used and the minerals contained in it are mined, at the same time, the supply shafts at the upper end are hermetically connected to the cold water shaft under pressure in such a way that a geothermal water circulation loop is obtained in which the geothermal water is again fed into the underground reservoir after contacting the energy via heat exchangers without contacting the biosphere.

The disadvantages of this method are the unreasonably large depth of the drilled wells, as well as its high cost due to the need to drill two or more deep wells with their insufficiently high productivity.

A known method of downhole steam generation using the deep heat of the Earth (RU 2360095 C2, F24J 3/08, 2006), comprising pre-drilling with a continuous face by a mechanical rotary method using a drilling rig of the initial section of a vertical well with a specified diameter and at a given depth with the fastening of this well with the installation of the first and second casing strings - the direction and the conductor; in this case, after the conductor, the third casing string is lowered into the well until the bottom, and into the annulus between asbestos-cement solution is injected with it and the conductor and further drilling of the well is carried out by thermal drilling using a solid fuel drill with a gradual descent of the casing to the estimated bottom hole depth, at which the rock temperature is determined, which is sufficient to produce saturated and superheated steam, while the hole is lowered to the bottom, the bottom-hole part of which is a heat exchanger with heating surfaces and holes for spraying water into which water is supplied through the barrel to form ra, which is raised up to the trunk casing wellhead whence it is fed to customers.

The disadvantages of this invention are structural complexity, high material consumption of the structure and low productivity.

A known method of producing energy from petrothermal sources and a device for its implementation

According to the known method, water is supplied through the injection well, which, under the influence of the high temperature of the underground collector, acquires excess temperature, turns into steam or a two-phase steam-water mixture and enters the separator through the production well to the surface for further supplying steam to the turbines of the petro thermal power plant (Petro TPP) and water to the thermal network of petrothermal supply stations (PetroTS). The formed condensate and the spent coolant are chemically cleaned and again pumped into the injection well. With a well depth of 10,000 meters and a diameter of 200-500 mm, under favorable conditions for rock permeability, the heating capacity of the petrocirculation system (PCS) is about 200 Gcal / h.

The developed heat-exchange surface is possessed by layers of porous rocks and zones of natural fracturing, encountered at various depths, the permeability of which provides forced filtration of the coolant with efficient heat transfer and extraction of rock thermal energy, or heat transfer surfaces artificially created by hydraulic fracturing in low-permeable massifs.

The circulation system for extracting underground heat consists of the following main elements: injection (injection) well; underground boiler-collector, including a zone of natural or artificial fracturing; production well, through which the fluid is delivered to the surface, and the surface complex, which may include a turbine room, cooling towers, intermediate heat exchangers, pipelines, etc. (N. A. Gnatus, M. D. Khutorskoy “HEAT“ DRY ”ROCKS - AN INEXPENDABLE RENEWABLE SOURCE OF ENERGY.” Journal of Lithology and Minerals, M., 2010, N ° 6, p.1-9) .

A disadvantage of the known technical solutions is that the creation of a petrothermal circulation system is provided by two deep wells, which limits the area of heat exchange with the underground collector, and also significantly increases the cost of the system at low productivity.

SUMMARY OF THE INVENTION

The objective of the group of inventions is to obtain energy from petrothermal sources using the heat of solid "dry" hot rocks of the earth's interior from one deep well while making it possible to plan the amount of energy produced.

The technical result from the use of the proposed technical solutions is to increase the amount of energy received while reducing the cost of its receipt.

In terms of the method, the problem is solved, and the technical result is achieved due to the fact that in the method of obtaining energy from petrothermal sources, including drilling from the earth's surface of a deep well, at least until it enters a hot dry formation, followed by injection through the well as heat carrier of water with the formation in a hot dry layer of rock water vapor, the withdrawal of the formed vapor to the earth's surface and the creation of a petrothermal circulation system, water is pumped through a pump battening pipe positioned in the well annulus to form spaces, the withdrawal of the generated steam is conducted through the annulus, and the petrothermal circulation system is created by killing at least one side well from the well in a hot, dry rock formation.

And also due to the fact that the well is drilled to a depth of 7-9 km.

And also due to the fact that the lateral wellbores are cut horizontally and / or at an angle to the well.

And also due to the fact that water vapor enters at least one sidetrack that is cut from the well.

It is preferable that the generated steam is used to produce electric and / or thermal energy, and the used steam after condensation in the form of water is again fed into the well and injected to form a closed water circuit.

In the particular case of execution, water is pumped into a hot dry rock formation through a perforated section of the injection pipe installed in the well.

In terms of the device, the task is solved, and the technical result is achieved due to the fact that in the device for receiving energy from petrothermal sources, containing a deep well drilled from the earth's surface and reaching the zone of a hot dry rock formation, and a pumping station, the deep well is the main a well, which is equipped with at least one cut-in sidetrack in the area of the hot dry rock formation, and coaxially located inside the injection pipe with the formation of an annular space connected to the pumping station.

And also due to the fact that the sidetracks are cut horizontally and / or at an angle to the main well.

It is preferable that the discharge pipe in a hot dry formation is provided with a perforated portion.

Preferably, the main well, at least in an area close to the earth's surface, is provided with a casing.

And also due to the fact that the device is equipped with a surface complex connected to the annular space of the main well and containing a heat and / or power station and / or water treatment plant and pump station.

The method is as follows.

To develop a source of deep heat of a hot mountain mass of the earth's crust, a deep well is drilled from the earth's surface. Well drilling is a process of rock destruction with the help of special equipment and drilling equipment. There are three types of drilling: vertical, horizontal and directional. The beginning of a well on the earth's surface is called the mouth, the bottom is the bottom. In the process of drilling the well, geological complications can occur - collapses, in this case the well is equipped with a casing - a pipe, which serves to strengthen the walls and isolate the wellbore. The well may be partially equipped with a casing, since it is not economically feasible to use a casing in the zone of no geological complications.

A deep well is drilled at least before it enters a hot, dry rock formation. It is known that in order to generate energy at the PerOTES in the face, it is necessary to reach a temperature of 250-280 ° C (N. A. Gnatus, M. D. Khutorskoi “HEAT OF“ DRY ”ROCKS - INEXISABLE RENEWABLE SOURCE OF ENERGY.” Journal “Lithology and Useful Fossils ”, M., 2010, N ° 6, pp. 1-9)

The deep characteristics of the heat fluxes of the earth's interior on planet Earth are not the same. If we proceed from the average gradient of temperature increase by 100 meters of a + (2-5 °) C deep, then temperatures of 250 ° C and higher can be achieved with a drilling depth of 7-9 km. However, there are some limited zones of the earth's crust, for example Cooper Bassin in South Australia, where the indicated rock temperatures are already reached at a depth of 3.5 - 4 km.

As soon as the deep well reaches the zone where the rock temperature reaches about 250 ° C, geophysical studies are carried out to identify reservoir properties of the formation. In the absence of zones of natural fracturing, they are created artificially - by hydraulic fracturing (hydraulic fracturing), carried out in any known manner. In the presence of a developed heat-exchange surface in a red-hot dry mountain massif, at least one side trunk is slaughtered in order to create a petrothermal circulation system (PCS) in the uncased part of the borehole in a deep well. The length, diameter and number of slaughtered sidetracks are calculated values and determine the area of the heat exchange surface with a red-hot mountain range. Sidetracks can be killed, both during the drilling of the main well and after its completion.

Inside the drilled deep well, an injection pipe is installed with the formation of an annulus (annular gap), connected to a pump station, through which to a face under high pressure into deeply lying layers , „„ _{DO <}

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pump water. For uniform distribution of water at the bottom of the well, the end section of the injection pipe is perforated. In the near-wellbore zone in a hot mountain massif, under high pressure, water flows through the collector, the pore space of the entire bottomhole lottery, generated in water vapor, which, under high pressure, enters at least one lateral well, cut from the well, and then into the annular the space of the cased part of the wellbore. In the annulus, water vapor rises to the earth's surface (to the wellhead) with its subsequent use to produce electric and / or thermal energy. Used steam after condensation in the form of water is again fed into the injection pipe of a deep well and injected into deeply lying formations with the formation of a closed water circuit.

The volume of energy generated by a petrothermal well for generating thermal or electric energy is directly proportional to the heating area in the petrothermal circulation system of the bottomhole zone. The heating area is achieved by the number of slaughtered sidetracks.

An example implementation of the method.

The main well is drilled from the earth's surface with a call into a hot dry rock formation to a depth of 7,000 meters, where a temperature of + 250 ° C is provided at the bottom of the well. In the uncased part of the well in a hot dry formation, four sidetracks are cut at an angle to the main well. An injection pipe is installed in the well through which 280 cubic meters of water are pumped. Water under high pressure passes through the reservoir, the pore space of the entire bottomhole lottery, generated in water vapor, which, under high pressure, enters the cut sidetracks, and then into the annular space of the cased part of the wellbore. In the annulus, water vapor rises to the wellhead (to the earth's surface). At the wellhead, thermal energy of 246 Gcal steam is obtained. Then the steam is fed to the petroelectric power station and petrothermal station, where its energy is converted into electric and thermal. The used steam after condensation in the form of water enters the pumping station, from where it is again fed into the injection pipe of the deep well and injected into deeply lying formations with the formation of a closed water circuit. Water is made from an artesian well. Brief Description of the Drawings

In more detail, the group of inventions is illustrated by drawings.

Figure 1 conventionally depicts a flow diagram of a process for generating energy from petrothermal sources; figure 2 is a vertical section of the well with a straight bottom and sidetracks cut at an angle to the well; in FIG. 3 - the same with a horizontal bottom and a horizontally slaughtered sidetrack.

For clarity, the relationship between the geometric dimensions of the individual elements in the drawings is changed.

The technological scheme (Figure 1) contains the main well 1 with the mouth 2 and the bottom

3, drilled from the earth’s surface 4 into a hot dry formation of rock 5 and provided in the area close to the earth’s surface 4 with a casing 6, in a hot dry formation of rock 5, side trunks 8 cut in the uncased part 7 and coaxially installed inside the discharge pipe 9 with the formation of the annulus 10. The discharge pipe 9 is connected to the pumping station And, the input of which is also connected to the artesian well 12. The annulus 10 communicates with the power plant 13, with the removal of electricity to consumers 14, and etroteplostantsiey 15 with heat consumer 16, which in turn is connected to a pumping station 1 January.

The injection pipe 8 of the main well 1 with a direct face 3 (Figure 2) and a horizontal face 3 (Figure 3) in a hot dry formation of rock 5 with a zone of natural or artificial permeability 17 contains a perforated section 18.

The scheme works as follows.

To the main well 1 (Fig. 1), drilled from the earth's surface 4 into a hot dry layer of rock 5, from the mouth 2 through the injection pipe 9 through its perforated section 18 (Fig. 2 and Fig. 3) to the bottom 3 in a hot massif water is supplied under high pressure to the zone of natural or artificial permeability 17 of the hot dry formation 5 from the pump station 1 1. Due to the contact of water with hot rock at a temperature of about 250 ° C, water is converted into water vapor and through the pore space of the zone of natural or artificial permeability 17 rapidly under high pressure enters the lateral shafts 8 cut into the uncased part 7 of the main well 1 into the annulus 10 , limited including a casing 6. Then the steam enters the wellhead 2 and then to consumers for energy production: at the power plant 13 - electricity with a discharge to consumers 14 and to petroteplostation 15 - thermal energy with heat being supplied to consumers 16. The water generated during steam condensation is returned to pump station 11, thereby creating a closed water circuit. Losses of water in the process can be replenished from an artesian well 12 and / or other sources of water, which can be used as a coolant.

Industrial applicability

Thus, the proposed technical solutions make it possible to plan the productivity of a petrothermal well by the amount of energy extracted by calculating the required heat transfer surface in hot dry rock formations and ensuring it by cutting the estimated number of sidetracks.

Given the high cost of the drilling process, in order to create petrothermal wells, in particular, upgraded used oil and gas wells can be used.

The creation of a power system based on the use of the deep heat of the earth's interior makes it possible to provide the world’s population with fairly cheap heat and electricity through the use of fundamentally new solutions in the absence of any harmful emissions into the atmosphere, soil and water bodies that adversely affect human health and the environment

Claims

10 FORMULATION OF THE INVENTION

1. A method of obtaining energy from petrothermal sources, including drilling from the earth's surface of a deep well, at least until it enters a hot dry formation, followed by injection of water through the well as a heat transfer medium with the formation of water vapor in the hot dry formation, removing the generated steam to the earth's surface and the creation of a petrothermal circulation system, characterized in that the water is pumped through an injection pipe installed in the well with the formation of the annulus, the formed steam is discharged through the annulus, and the petrothermal circulation system is created by killing at least one sidetrack from the well in a hot, dry rock formation.

2. The method according to claim 1, characterized in that the well is drilled to a depth of 7-9 km.

3. The method according to claim 1 or claim 2, characterized in that the side wells are cut horizontally and / or at an angle to the well.

4. The method according to p. 3, characterized in that the water vapor enters at least one lateral well, cut from the well.

5. The method according to claim 4, characterized in that the generated steam is used to produce electrical and / or thermal energy.

6. The method according to claim 5, characterized in that the steam used after condensation in the form of water is again fed into the well and injected to form a closed water circuit.

7. The method according to p. 3, characterized in that the water is pumped into a hot dry rock formation through a perforated section of the injection pipe installed in the well.

8. Device for producing energy from petrothermal sources, containing a deep well drilled from the earth's surface and reaching the zone of a hot dry rock formation, and a pumping station, characterized in that the deep well is the main well, which is equipped with at least one cut lateral trunk in the zone of a hot dry rock formation, and coaxially located inside the discharge pipe with the formation of the annulus connected to the pumping station.

9. The device according to claim 8, characterized in that the sidetracks are cut horizontally and / or at an angle to the main well. eleven

10. The device according to claim 9, characterized in that the discharge pipe in a hot dry formation is provided with a perforated section.

1 1. The device according to claim 9 or claim 10, characterized in that the main well, at least in an area close to the earth's surface, is equipped with a casing.

12. The device according to claim P, characterized in that it is equipped with a surface complex connected to the annular space of the main well and containing a heat and / or power station and / or water treatment plant and pump station.