CN110617466A - Supercritical hydrothermal combustion type steam generator for ultra-deep underground heavy oil thermal recovery - Google Patents

Abstract

The invention discloses a supercritical hydrothermal combustion type steam generator for thermal recovery of heavy oil in an ultra-deep well, comprising three parts: a generator head, a generator upper part and a generator lower part. The head of the generator is equipped with an electric heating rod to ensure the occurrence of supercritical hydrothermal combustion reaction; the upper part of the generator includes a primary combustion chamber and a secondary combustion chamber to ensure sufficient supercritical hydrothermal combustion reaction of fuel and oxidant; the nozzle at the lower part of the generator And the tapering port ensures that the parameters of the reaction product meet the requirements of heavy oil production in the oil field; the cooling water in the generator is used to ensure that the generator does not overheat to protect the safe operation of the generator. The device reduces the cost of heavy oil exploitation, improves heat utilization efficiency, prevents the discharge of pollutants, and realizes efficient exploitation of deep and offshore oil reservoirs.

Description

A supercritical hydrothermal combustion steam generator for thermal recovery of heavy oil in ultra-deep wells

technical field

The invention belongs to the technical field of heavy oil exploitation and supercritical water, and relates to a steam generator, in particular to a supercritical hydrothermal combustion steam generator used for thermal recovery of heavy oil in an ultra-deep well.

Background technique

Supercritical Water (SCW for short) refers to water in a special state whose temperature and pressure are both higher than its critical point (T=374.15°C, P=22.12MPa). In this state, only a small amount of hydrogen bonds exist in water, the dielectric constant is close to that of organic solvents, and it has low viscosity and high diffusion coefficient. Make organic matter and oxygen miscible with supercritical water in any proportion, so that the heterogeneous reaction becomes a homogeneous reaction, and the mass transfer and heat transfer resistance between substances are greatly reduced.

Supercritical Hydrothermal Combustion (SCHC) technology refers to a new type of combustion method in which fuel and oxidant undergo violent oxidation reactions in a supercritical water environment to produce a hydrothermal flame (Hydrothermal Flame). Compared with conventional combustion technologies , Supercritical hydrothermal combustion technology has significant advantages such as low combustion core temperature, clean reaction products, and small reactor.

At present, heavy oil production methods in oilfields mainly use steam injection boilers on the ground to generate steam, which is injected downhole and combined with steam huff and puff, steam flooding and steam-assisted gravity drainage to recover heavy oil. The above methods mainly have the following bottlenecks: Ground steam generators occupy a large area and cannot be arranged on offshore oil exploration platforms with limited space, which limits the exploitation of heavy oil at sea; the heat loss is large. The exhaust gas loss of the surface steam generator is about 20%, the heat loss of the surface gas pipeline is about 15%, the heat loss of the injection wellbore is about 10% per kilometer, and the overall thermal efficiency is low; the gas injection boiler inevitably produces exhaust gas containing SOx and NOx It will cause environmental pollution; the depth of recoverable oil reservoirs is limited. Among the discovered heavy oil reservoirs, the reserves of heavy oil with a reservoir depth greater than 1700m account for about 40% of the proven reserves. In addition to the application depth of steam huff and puff up to 1800 meters, steam flooding and steam-assisted gravity drainage technology with high recovery rate are mainly applied in oil reservoirs with a depth of less than 1200 meters.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art, and solve the problems of huge heat loss, environmental pollution, mining cost higher than the limited mining depth and other problems existing in the existing gas injection boiler steam production technology for mining heavy oil, the purpose of the present invention is to provide a method for The supercritical hydrothermal combustion steam generator for thermal recovery of heavy oil in ultra-deep wells can be ignited and burned directly in the well to generate steam and carbon dioxide, reducing the high cost of heat loss caused by conventional ground-generated steam transportation, and the reactor is relatively injected The small size of the gas boiler can reduce a lot of material costs and land costs, and can automatically adjust the pressure to the pressure required for the thermal recovery of heavy oil in the well. Exploitation of ultra-deep oil reservoir resources.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A supercritical hydrothermal combustion steam generator for thermal recovery of heavy oil in an ultra-deep well, comprising a generator head 18, a generator upper part 19 and a generator lower part 25 connected and assembled in sequence, the generator head 18 It is an end cover structure, on which a nozzle opening 5 is arranged, and a nozzle passing through the generator head 18 is installed in the nozzle opening 5. The nozzle includes a nozzle liner 3, a nozzle shell 4 and an ignition rod 1, and the nozzle liner 3 sides There is a primary fuel inlet 2 on the wall, several atomizing nozzles on the bottom, the ignition rod 1 is inserted into the nozzle liner 3, the upper part of the nozzle shell 4 is provided with a primary oxidant inlet 15, and the outside of the nozzle shell 4 is a nozzle single spiral structure.

The inner area of the upper part 19 of the generator is formed by connecting the primary combustion chamber 10 above and the secondary combustion chamber 11 below through the throat assembly 23, and the nozzle 13 located at the lower part 25 of the generator is connected to the bottom of the secondary combustion chamber 11, wherein Both the atomizing nozzle and the single spiral structure of the nozzle are located at the upper part of the primary combustion chamber 10 .

The generator head 18 is provided with a pressure measuring port 17, a flame detection port 6 and a temperature measuring port 16 communicating with the primary combustion chamber 10, and the generator upper part 19 or the generator lower part 25 is provided with a communication secondary The temperature measuring port 2 24 of the combustion chamber 11 and the lower part 25 of the generator are provided with a pressure measuring port 2 14 and a temperature measuring port 3 26 communicating with the area below the nozzle 13 .

Described shower head 13 has some obliquely downward spouts of 45-80° with the horizontal plane.

The primary combustion chamber 10 is surrounded by a refractory component 20, and the material of the refractory component 20 includes, but is not limited to, one or more inorganic metals or non-metals available on the market such as silicon carbide, cermets, and silicon nitride. Material.

The side wall of the upper part 19 of the generator is provided with a secondary fuel/oxidant dual channel 22, and the generator head 18 is provided with a secondary fuel inlet 8 and a secondary oxidant which communicate with the secondary fuel/oxidant dual channel 22 Inlet 17, the lower end of the secondary fuel/oxidant dual channel 22 is provided with several rows of secondary fuel/oxidant mixing outlets that are inclined downward and communicate with the secondary combustion chamber 11.

The nozzle 13 is arranged in the lower part 25 of the generator, and the side wall of the upper part 19 of the generator is provided with a cooling water channel 21, and the cooling water channel 21 is located outside the secondary fuel/oxidant dual channel 22, and the generator head 18 A cooling water inlet 9 communicating with the cooling water upper channel 21 is provided on the top, and a cooling water lower channel 12 communicating with the cooling water upper channel 21 is provided on the upper side wall of the lower part 25 of the generator. There is a cooling water outlet connected to the spray nozzle 13.

The secondary fuel/oxidant double channel 22 is a double spiral descending structure, and the cooling water upper channel 21 and the cooling water lower channel 12 are a single spiral descending structure.

The spiral planes of the secondary fuel/oxidant double channel 22, the cooling water upper channel 21 and the cooling underwater channel 12 are all at 10-45° to the horizontal plane, and the secondary fuel/oxidant mixing outlet is at 45-80° to the horizontal plane .

The bottom end of the lower part 25 of the generator is a shrinking nozzle structure as a whole.

Compared with prior art, the beneficial effect of the present invention is:

(1) The invention discloses a supercritical hydrothermal combustion steam generator for thermal recovery of ultra-deep downhole heavy oil, which can avoid smoke exhaust and steam transportation of steam boilers by using supercritical hydrothermal combustion technology to generate steam underground More than 45% of the heat loss generated by the pipeline improves the overall thermal efficiency, and the device is compact in structure and can be placed underground, so that the process of generating steam does not need to be generated on the ground using a huge gas injection boiler, effectively reducing investment costs and land costs, thereby improving the economics of the system.

(2) The invention discloses a supercritical hydrothermal combustion type steam generator for thermal recovery of ultra-deep downhole heavy oil. The supercritical hydrothermal combustion technology is used to generate steam in the downhole, and the products are all injected into the downhole without going to the atmosphere. The inevitable toxic exhaust SOx and NOx of medium-emission gas injection boilers protect the environment.

(3) A supercritical hydrothermal combustion type steam generator for thermal recovery of ultra-deep downhole heavy oil disclosed by the present invention is not limited by well depth, and can be used in deep oil reservoirs and ultra-deep oil reservoirs that are difficult to utilize by conventional oil recovery techniques As well as offshore reservoirs, improving the utilization rate of oilfield reservoirs.

Therefore, the present invention discloses a supercritical hydrothermal combustion steam generator for thermal recovery of heavy oil in ultra-deep wells, which reduces the cost of heavy oil production, improves heat utilization efficiency, reduces pollutant discharge, and is not subject to exploitation. The well depth is limited, and the efficient exploitation of deep and offshore oil reservoirs is realized.

Description of drawings

Fig. 1 is a structural schematic diagram of the device of the present invention.

Among them, 1 is the ignition rod, 2 is the primary fuel inlet, 3 is the nozzle inner tank, 4 is the nozzle shell, 5 is the nozzle mouth, 6 is the flame detector mouth, 7 is the pressure measuring port, 8 is the secondary fuel inlet, 9 10 is the primary combustion chamber, 11 is the secondary combustion chamber, 12 is the cooling water channel, 13 is the nozzle, 14 is the pressure measuring port, 15 is the primary oxidant inlet, 16 is the temperature measuring port, 17 is the secondary The secondary oxidant inlet, 18 is the generator head, 19 is the upper part of the generator, 20 is the refractory material, 21 is the cooling water channel, 22 is the secondary fuel/oxidant dual channel, 23 is the throat assembly, 24 is the temperature measuring port, 25 is the lower part of the generator, and 26 is the temperature measuring port.

Detailed ways

The implementation of the present invention will be described in detail below in conjunction with the drawings and examples.

As shown in Figure 1, a supercritical hydrothermal combustion steam generator for thermal recovery of heavy oil in an ultra-deep well, its main part includes a generator head 18, a generator upper part 19 and a generator lower part that are sequentially connected and assembled 25, wherein, the interior of the upper part 19 of the generator is the main reaction zone, which can be formed by connecting the upper primary combustion chamber 10 and the lower secondary combustion chamber 11 through the throat assembly 23, and the primary combustion chamber 10 can be formed by surrounding the refractory assembly 20, The material of the refractory component 20 includes, but is not limited to, one or more commercially available inorganic metal or non-metal materials such as silicon carbide, cermet, and silicon nitride. Generator bottom 25 can be provided with sprinkler head 13, has some spouts that become 45-80 ° with the horizontal plane on the shower nozzle 13, and the bottom of generator lower portion 25 can be a contraction nozzle structure as a whole.

Generator head 18 is the important structure of the present invention, takes the form of end cap, and the core structure on it is mouth 5, and longitudinal penetration generator head 18 is housed in nozzle mouth 5 and stretches into main reaction zone (in being divided into When primary combustion chamber 10 and secondary combustion chamber 11, then stretch into the nozzle of primary combustion chamber 10). Wherein the mouth 5 preferably can be arranged on the central position of generator head 18, and nozzle comprises nozzle liner 3, nozzle shell 4 and ignition rod 1, and nozzle liner 3 side walls have primary fuel inlet 2, and bottom end has A number of atomizing nozzles, the ignition rod 1 is inserted into the nozzle liner 3, the upper part of the nozzle shell 4 is provided with a primary oxidant inlet 15, and the outside of the nozzle shell 4 is a nozzle single spiral structure. The bottom of the secondary combustion chamber 11 is connected to the spray nozzle 13 located at the lower part 25 of the generator, wherein the atomization nozzle and the single spiral structure of the nozzle are all at the top of the main reaction zone (when divided into the primary combustion chamber 10 and the secondary combustion chamber 11, then in the upper part of the primary combustion chamber 10).

The side wall of the upper part 19 of the generator can be provided with a secondary fuel/oxidant dual channel 22, and the secondary fuel/oxidant dual channel 22 can be a double spiral descending structure, and the spiral plane is 10-45° from the horizontal plane, while the generator head The part 18 is provided with a secondary fuel inlet 8 and a secondary oxidant inlet 17 communicating with the secondary fuel/oxidant dual channel 22, and the lower end of the secondary fuel/oxidant dual channel 22 is inwardly opened with several rows of obliquely downward and secondary The secondary fuel/oxidant mixing hole communicated with the combustion chamber 11 has an angle of 45-80° to the horizontal plane.

Further, the side wall of the upper part of the generator 19 is provided with a cooling water upper channel 21, the cooling water upper channel 21 is located outside the secondary fuel/oxidant double channel 22, and the generator head 18 is provided with a cooling water inlet communicating with the cooling water upper channel 21 9. The upper side wall of the generator lower part 25 is provided with a cooling water channel 12 connected to the cooling water upper channel 21 through a vertical hole, and a cooling water outlet connected to the nozzle 13 is opened below the cooling water channel 12 . Both the cooling water upper channel 21 and the cooling water lower channel 12 can be of a single spiral descending structure, and the spiral plane is 10-45° from the horizontal plane.

Further, the present invention also includes some monitoring means, that is, the generator head 18 is provided with a pressure measuring port-7, a flame detection port 6 and a temperature measuring port-16 communicating with the primary combustion chamber 10, and The upper part 19 of the generator or the lower part 25 of the generator is provided with a temperature measuring port 2 24 which communicates with the secondary combustion chamber 11, and the lower part 25 of the generator is provided with a pressure measuring port 2 14 and a temperature measuring port 3 26 which are connected to the area below the nozzle 13, so as to realize the Monitoring of pressure and temperature of corresponding parts.

According to above structure, technological process of the present invention is as follows:

The fuel aqueous solution of a certain concentration under supercritical pressure enters the nozzle liner 3 through the primary fuel inlet 2, is sprayed into the primary combustion chamber 10 through the atomizing nozzle at the bottom after being heated by the heating rod 1; the oxidant under supercritical pressure passes through the primary oxidant inlet 15 enters the annular cavity of the nozzle shell 4 and the nozzle liner 3, spins through the lower spiral channel, enters the primary combustion chamber 10, mixes with the primary fuel, ignites and burns stably, and the high-temperature product of the reaction passes through the throat assembly 23 and enters the secondary combustion chamber 11.

Another stream of fuel aqueous solution with a certain concentration under supercritical pressure enters the secondary fuel/oxidizer double channel 22 of the double helix through the secondary fuel inlet 8, and another stream of oxidant under supercritical pressure enters the secondary fuel through the secondary oxidizer inlet 17. Fuel/oxidant double channel 22, two streams of fluids flow through the spiral channel through different layers to the lower end of secondary fuel/oxidant dual channel 22, and two streams of fluid flow into secondary combustion chamber 11 through secondary fuel/oxidant mixing outlet hole for secondary combustion Secondary combustion, the reaction product is sprayed into the lower part 25 of the generator through the nozzle 13 inclined downward.

One stream of cooling water under supercritical pressure enters the cooling water upper channel 21 of the single helix through the cooling water inlet 9, flows down through the single helix, and flows into the single channel of the cooling water lower channel through some vertical holes opened in the cooling water channel 12. The spiral channel then enters the lower part 25 of the generator to mix with the reaction product, and then the mixture flows out of the steam generator through the converging nozzle.

In summary, the present invention discloses a supercritical hydrothermal combustion steam generator for thermal recovery of heavy oil in an ultra-deep well, including three parts: a generator head, an upper part of the generator and a lower part of the generator. The head of the generator is equipped with an electric heating rod to ensure the occurrence of supercritical hydrothermal combustion reaction; the upper part of the generator includes a primary combustion chamber and a secondary combustion chamber to ensure sufficient supercritical hydrothermal combustion reaction of fuel and oxidant; the nozzle at the lower part of the generator And the tapering port ensures that the parameters of the reaction product meet the requirements of heavy oil production in the oil field; the cooling water in the generator is used to ensure that the generator does not overheat to protect the safe operation of the generator. The device reduces the cost of heavy oil exploitation, improves heat utilization efficiency, prevents the discharge of pollutants, and realizes efficient exploitation of deep and offshore oil reservoirs.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in this document. within the scope of protection of the invention.

Claims (10)

1. A supercritical hydrothermal combustion steam generator for thermal recovery of heavy oil in an ultra-deep well, comprising a generator head (18), a generator upper part (19) and a generator lower part (25) connected in sequence , the generator head (18) is an end cap structure, on which a nozzle opening (5) is provided, and a nozzle passing through the generator head (18) is installed in the nozzle opening (5), it is characterized in that the The nozzle includes a nozzle liner (3), a nozzle shell (4) and an ignition rod (1). The side wall of the nozzle liner (3) has a primary fuel inlet (2), and a number of atomization nozzles are opened at the bottom end. The ignition rod ( 1) The nozzle liner (3) is inserted inside, the primary oxidant inlet (15) is provided on the upper part of the nozzle shell (4), and the outer part of the nozzle shell (4) has a single nozzle helical structure. 2. according to the described supercritical hydrothermal combustion type steam generator that is used for the thermal recovery of ultra-deep downhole heavy oil according to claim 1, it is characterized in that, the inner region of the generator top (19) is formed by the primary combustion chamber ( 10) and the secondary combustion chamber (11) below are connected through the throat assembly (23). Both the spout and the single helix structure of the nozzle are in the upper part of the primary combustion chamber (10). 3. The supercritical hydrothermal combustion type steam generator for thermal recovery of ultra-deep downhole heavy oil according to claim 2, characterized in that, the generator head (18) is provided with a combustion chamber (10 ) connected pressure measuring port one (7), flame detection port (6) and temperature measuring port one (16), the upper part of the generator (19) or the lower part of the generator (25) is provided with a secondary combustion chamber (11 ), the lower part of the generator (25) is provided with pressure measuring port two (14) and temperature measuring port three (26) connected to the area below the nozzle (13). 4. The supercritical hydrothermal combustion steam generator for thermal recovery of ultra-deep downhole heavy oil according to claim 2, characterized in that, the nozzle (13) is provided with a number of nozzles at an angle of 45-80° to the horizontal plane. The slanted downward spout. 5. The supercritical hydrothermal combustion steam generator for thermal recovery of ultra-deep downhole heavy oil according to claim 2, characterized in that the primary combustion chamber (10) is surrounded by refractory components (20). 6. The supercritical hydrothermal combustion type steam generator for thermal recovery of ultra-deep downhole heavy oil according to claim 2, characterized in that, the side wall of the upper part (19) of the generator is provided with a secondary fuel/oxidant Dual channels (22), the generator head (18) is provided with a secondary fuel inlet (8) and a secondary oxidant inlet (17) communicated with the secondary fuel/oxidant dual channel (22), the two The lower end of the secondary fuel/oxidant dual channel (22) is inwardly provided with several rows of secondary fuel/oxidant mixing outlet holes that are inclined downward and communicate with the secondary combustion chamber (11). 7. The supercritical hydrothermal combustion type steam generator for thermal recovery of ultra-deep downhole heavy oil according to claim 6, characterized in that, the nozzle (13) is arranged in the lower part (25) of the generator, and the The side wall of the upper part of the generator (19) is provided with a cooling water passage (21), and the cooling water passage (21) is located outside the secondary fuel/oxidant double passage (22), and the generator head (18) is provided with a A cooling water inlet (9) connected to the cooling water upper channel (21), the upper side wall of the generator lower part (25) is provided with a cooling water lower channel (12) communicating with the cooling water upper channel (21), the cooling A cooling water outlet connected to the shower head (13) is provided below the underwater channel (12). 8. The supercritical hydrothermal combustion type steam generator for thermal recovery of ultra-deep downhole heavy oil according to claim 7, characterized in that, the secondary fuel/oxidant dual channel (22) is a double-helix descending structure, The cooling water upper channel (21) and the cooling water lower channel (12) have a single spiral descending structure. 9. The supercritical hydrothermal combustion type steam generator for thermal recovery of ultra-deep downhole heavy oil according to claim 8, characterized in that, the secondary fuel/oxidant dual channel (22), the cooling water upper channel (21 ) and the spiral plane of the cooling underwater passage (12) are 10-45° with the horizontal plane, and the secondary fuel/oxidant mixing outlet is 45-80° with the horizontal plane. 10. The supercritical hydrothermal combustion steam generator for thermal recovery of ultra-deep downhole heavy oil according to any one of claims 1 to 9, characterized in that the bottom end of the lower part (25) of the generator is as a whole Shrink the nozzle structure.