CN-116624134-B - Supercritical hydrothermal combustion type underground multi-element hot fluid generation method and device

CN116624134BCN 116624134 BCN116624134 BCN 116624134BCN-116624134-B

Abstract

The invention discloses a supercritical hydrothermal combustion type underground multi-element hot fluid generating method and device, wherein an I-stage combustion area, an II-stage combustion area, an III-stage reaction area, an IV-stage reaction area and a V-stage blending area are arranged, cold-state incidence stable ignition of fuel in a starting stage is realized through a hot surface forced ignition mode, the ignition requirement of the cold-state fuel of an underground device is met, high-flow materials are axially graded, upper-stage combustion/reaction provides heat for the lower-stage reaction, stable supercritical hydrothermal combustion and rapid oxidation of all-stage materials are ensured in the underground device with limited radial space, large-flow quantification of the underground multi-element hot fluid generating device is realized, a hydraulic turbine is arranged at the bottom of the multi-element hot fluid generating device, pressure potential energy of the generated supercritical fluid is effectively utilized, and meanwhile, parameter self-adjustment of the multi-element hot fluid is realized, and the method and device can provide a feasible scheme and technical guidance for efficient and clean thick oil hot recovery technology.

Inventors

ZHANG JIE
Huang Rongpu
ZHANG TUO
ZHANG HAO
WANG KAI
DANG FANING

Assignees

西安理工大学

Dates

Publication Date: 20260508
Application Date: 20230516

Claims (7)

1. A supercritical hydrothermal combustion type underground multi-element hot fluid generating device is characterized by comprising a top end cover (1), an upper end cover (4), a pressure-bearing wall (7) and a bottom end cover (11) which are sequentially connected, wherein an I-stage fuel igniter is arranged in the top end cover (1), a reaction chamber three-stage spiral wall (6) and an I-stage combustion chamber spiral cooling wall (5) are sequentially arranged on the inner side of the upper end cover (4) from outside to inside, the reaction chamber three-stage spiral wall (6) is positioned on the inner side of the pressure-bearing wall (7), an area surrounded by the I-stage combustion chamber spiral cooling wall (5) is an I-stage combustion area A1, and a II-stage combustion area A2 is sequentially arranged below the I-stage combustion area A1, The III-level reaction zone A3, the IV-level reaction zone A4 and the V-level mixing zone A5, three spiral channels are arranged on the three-level spiral wall (6) of the reaction chamber and are respectively correspondingly communicated with the III-level reaction zone A3, the IV-level reaction zone A4 and the V-level mixing zone A5, a top end cover (1) is provided with a channel of I-level fuel and a I, II-level oxidant channel, I, The II-stage oxidant channel is communicated with an I-stage combustion zone A1, a fuel inlet which is respectively correspondingly communicated with three spiral channels is formed in an upper end cover (4), a multi-element hot fluid outlet is formed in a bottom end cover (11), a core tube (2) and an inner sleeve (3) are arranged on the outer side of an I-stage fuel igniter, the inner sleeve (3) is connected in the top end cover (1), a spiral cooling wall (5) of the I-stage combustion chamber is connected to the inner sleeve (3), a circle of inclined holes are formed in the side wall of the lower portion of the core tube (2) along the circumferential direction, a round hole with the diameter larger than that of an igniter binding post (14) is formed in the closed end of the bottom of the core tube (2), the round holes on the inclined holes and the closed end of the bottom are used as I-stage fuel to be sprayed into an I-stage fuel inlet (16) of the I-stage combustion zone A1, and I-stage fuel inlets N1 and I are respectively formed in the top end cover (1) The fuel gas-liquid mixing device comprises a II-level oxidant inlet N2, an annular gap between the inner wall of a core tube (2) and the outer wall of a binding post (14) of an igniter, a I, II-level oxidant channel formed by the annular gap between the outer wall of the core tube (2) and the inner wall of an inner sleeve (3), three mutually independent spiral channels which are arranged outside a three-level spiral wall (6) of a reaction chamber and are used as III-level fuel and oxidant spiral channels (6-1), IV-level fuel spiral channels (6-2) and V-level mixing water spiral channels (6-3), wherein the upper end cover (4) is provided with the II-level fuel inlet N3, the III-level fuel and oxidant inlet N4, The method comprises the steps of connecting a grade IV fuel inlet N5 and a grade V mixing water inlet N6, connecting a grade II fuel inlet N3 with a spiral channel on the outer wall of a grade I combustion chamber spiral cooling wall (5), forming a grade II fuel channel by the spiral channel on the outer wall of the grade I combustion chamber spiral cooling wall (5), connecting a grade III fuel and oxidant inlet N4 with a grade III fuel and oxidant spiral channel (6-1), connecting a grade IV fuel inlet N5 with a grade IV fuel spiral channel (6-2), connecting a grade V mixing water inlet N6 with a grade V mixing water spiral channel (6-3), opening a plurality of through holes on the last circle of the grade III fuel and oxidant spiral channel (6-1) as grade III fuel and oxidant inlet (18), stopping the grade III fuel and oxidant spiral channel (6-1) at the grade III fuel and oxidant inlet (18), connecting the area between the outlet of the grade I combustion chamber spiral cooling wall (5) and the grade III fuel and oxidant inlet (18) as grade II combustion zone A2, connecting a plurality of through holes on the surface of the grade III fuel and oxidant spiral channel (6-3) as a plurality of small holes on the surface of the grade III fuel and oxidant spiral channel (19) which are arranged at the bottom of the grade IV fuel and the grade IV fuel (19) of the grade IV mixing water inlet (19), the V-stage mixing water inlet (20) is used, an IV-stage reaction zone A4 is formed between the IV-stage fuel inlet (19) and the V-stage mixing water inlet (20), and the area between the V-stage mixing water inlet (20) and the hydraulic turbine inlet cover (9) is a V-stage mixing zone A5.
2. The supercritical hydrothermal combustion type underground multi-element hot fluid generating device according to claim 1, wherein a rotating shaft (12) and a hydraulic turbine inlet cover (9) are arranged at the lower portion of the pressure-bearing wall (7), the rotating shaft (12) penetrates through the center of the bottom end cover (11), the middle portion of the rotating shaft (12) penetrates through the hydraulic turbine inlet cover (9), a hydraulic turbine (10) is arranged at the lower portion of the rotating shaft (12), a hydraulic turbine fluid inlet N7 is arranged on the hydraulic turbine inlet cover (9), and the rotating shaft (12) is respectively connected with the hydraulic turbine inlet cover (9) and the bottom end cover (11) in a rotating mode through thrust bearings.
3. The supercritical hydrothermal combustion type downhole multi-element hot fluid generating device according to claim 1, wherein a rotary wiper (8) is installed on the upper portion of the rotary shaft (12).
4. The supercritical hydrothermal combustion type downhole multi-element hot fluid generating apparatus according to claim 1, wherein the fuel fed into the stage I combustion zone A1, the stage II combustion zone A2, the stage III reaction zone A3, the stage IV reaction zone A4 is the same, and the blending water fed into the stage V blending water inlet N6 is oil field wastewater or softened water.
5. A supercritical hydrothermal combustion type underground multi-element hot fluid generation method is characterized in that an I-stage combustion zone, an II-stage combustion zone, a III-stage reaction zone, an IV-stage reaction zone and a V-stage blending zone are arranged on the basis of the supercritical hydrothermal combustion type underground multi-element hot fluid generation device according to any one of claims 1-4, normal-temperature I-stage fuel is sprayed into the I-stage combustion zone A1, supercritical hydrothermal combustion reaction is carried out under the assistance of an oxidant, II-stage fuel is spirally sprayed into the II-stage combustion zone A2, high-temperature combustion products of the I-stage fuel and residual oxidant are quickly mixed, supercritical hydrothermal combustion reaction is carried out under the assistance of the oxidant, III-stage fuel is sprayed into the III-stage reaction zone A3, rapid supercritical hydrothermal oxidation reaction is carried out under the assistance of the oxidant, IV-stage fuel is sprayed into the IV-stage reaction zone A4, the rapid thermal oxidation reaction is carried out under the assistance of the oxidant, the rapid thermal oxidation reaction is carried out under the assistance of the upstream III-stage fuel and the residual oxidant, the rapid thermal oxidation reaction is carried out under the assistance of the oxidant, and the rapid thermal blending of the V-stage fuel is carried out under the assistance of the rapid thermal mixing of the upstream-stage, and the rapid thermal mixing of the supercritical fluid is carried out under the rapid thermal mixing of the upstream-stage III-stage fuel, and the rapid thermal mixing of the supercritical fluid is carried out under the rapid thermal mixing of the upstream III-stage.
6. The method for generating the supercritical hydrothermal combustion type underground multi-element hot fluid according to claim 5, wherein the supercritical water is generated in the I-stage combustion zone A1 by igniting in a forced ignition mode, then the downstream all-stage reaction zone is heated, the I-stage combustion zone A1, the II-stage combustion zone A2, the III-stage reaction zone A3 and the IV-stage reaction zone A4 are filled with supercritical water, after initial conditions of stable reactions of all-stage fuels are established, all-stage reaction fuels and oxidants are injected, the supercritical hydrothermal combustion reactions and the rapid supercritical water oxidation reactions are generated until the I-stage combustion zone A1, the II-stage combustion zone A2, the III-stage reaction zone A3 and the IV-stage reaction zone A4 reach the conditions of normal operation conditions, V-stage mixed water flows into the V-stage mixing zone A5 and is mixed with upstream high-temperature reaction fluid to generate the supercritical multi-element hot fluid, after stable operation, cold stable incident combustion of the I-stage fuels is realized by the thermal spontaneous combustion mode, and the stable reaction processes of all-stage fuels are maintained, and the multi-element hot fluid with large flow is continuously generated.
7. The supercritical hydrothermal combustion type downhole multi-element hot fluid generating method according to claim 5, wherein the hydraulic turbine (10) is used for reducing the supercritical multi-element hot fluid pressure in the reaction zone, and the hydraulic turbine (10) drives the scraping and brushing device to rotate and wash the inner wall of the reaction chamber.

Description

Supercritical hydrothermal combustion type underground multi-element hot fluid generation method and device Technical Field The invention belongs to the technical field of thickened oil exploitation, and particularly relates to a supercritical hydrothermal combustion type underground multi-element hot fluid generation method and device. Background It has been found that in heavy oil reservoirs, the heavy oil reserves with a reservoir depth of more than 800m account for about 80% of the ascertained reserves, and about half of the reservoirs are buried at 1300-1700 m. Compared with conventional oil gas, the thickened oil has high colloid and asphaltene content, high viscosity and solidifying point and poor fluidity, so that the exploitation technology is more complicated than the development of the conventional oil gas, and the recovery ratio is relatively smaller. However, thick oil is extremely sensitive to temperature, and the viscosity is reduced by half every 10 ℃ increase. At present, the oil field mainly generates steam through a ground steam injection boiler and is injected into the underground, and thick oil is extracted by combining steam huff and puff, steam flooding and steam assisted gravity drainage thermal recovery technologies. However, the existing exploitation mode has the problems of large heat loss (heat loss of a surface device and a pipeline, heat loss of steam injected into a shaft), limited depth of an oil reservoir, large occupied area of the surface device and the like. The multi-element hot fluid technology is a crude oil extraction technology utilizing the synergistic effect of gas (N 2、CO2) and steam, and can form foam oil underground to increase the expansion coefficient and flowability of crude oil. The multi-element hot fluid is characterized in that 1) the high-temperature multi-element hot fluid heats an oil layer to obviously reduce the viscosity of thick oil, 2) the multi-element hot fluid contains a large amount of N 2 and CO 2, the gas is dissolved in crude oil under higher pressure to further reduce the viscosity of the crude oil, improve the expansion coefficient of the crude oil and interact with the crude oil to form foam oil to increase the fluidity of the crude oil, 3) the multi-element fluid has obvious pressurizing effect, 4) the expansion volume is enlarged, the volume of a high-pressure area formed by gas diffusion after the multi-element hot fluid is injected is obviously larger than that of a high-pressure area injected with steam, the pressurizing effect is obvious, 5) the heat loss of the oil layer is reduced, N 2 and CO 2 in the multi-element hot fluid are suspended above the oil layer, the temperature of the oil layer is maintained, and the heat loss is reduced. In combination, the generated multi-element hot fluid (steam, N 2、CO2 and the like) has the functions of thermal viscosity reduction and gas mixing viscosity reduction, so that the recovery ratio of thick oil is effectively improved. The supercritical hydrothermal combustion is to mix fuel compounds with a certain concentration in supercritical water (T >374.1℃, P >22.1 MPa) environment and when the temperature is higher than the self-ignition temperature, the fuel compounds are mixed with oxidant and then are ignited in the supercritical water to release huge heat, so that a hydrothermal flame is formed. The supercritical hydrothermal combustion reaction rate is high, the hydrothermal flame temperature is high and can reach 700-1100 ℃, the combustion efficiency of fuel is high, the supercritical hydrothermal combustion reaction device can be used as an efficient energy acquisition means, and the combustion process of fuel in supercritical water is direct heat transfer among molecules and has high heat exchange efficiency, so that the supercritical hydrothermal combustion reaction device has a compact structure. The supercritical hydrothermal combustion and the multi-element hot fluid steam injection technology are combined, a low-temperature high-pressure fuel solution and an oxidant are injected into a combustion device, the fuel is ignited to generate supercritical hydrothermal flame, and the multi-element hot fluid containing CO 2、H2 O and N 2 is generated by reaction and directly injected into an oil layer for thick oil thermal recovery, so that 1) the generator device has compact geometrical structure and meets the requirement of limited space in a well, 2) the device in the well is not limited by well depth, the device is suitable for deep and ultra-deep thick oil development, 3) the supercritical hydrothermal combustion device has no smoke discharging loss, ground heat loss and shaft heat dissipation loss are avoided, the energy utilization efficiency is improved, and the fuel consumption is reduced. The supercritical hydrothermal combustion type underground multielement thermal fluid steam injection technology meets the requirements of energy conservation, emission reduction and energy saf