Ultra-heavy oil circulation series production method and device under SAGD production mode

Abstract

The present invention relates to the technical field of oilfield production and production, and is a method and apparatus for circulating and serially producing super-heavy oil under a SAGD production model. The method and apparatus are as follows: superheated steam from a boiler is injected into well P of well group A via a boiler steam main line and a main steam injection line of well group A, heating the heavy oil in well P of well group A; high-temperature produced fluid from well P of well group A is injected into well P of well group B via a first liquid outlet line, a main steam injection line of well group B, and a third steam injection line, heating the heavy oil in well P of well group B; and produced fluid from well P of well group B is discharged and sent to a processing station for treatment, the processing station comprising well P of well group A, well I of well group A, well P of well group B, well I of well group B, and a boiler steam main line. The method can effectively increase the number of wells in operation, crude oil production, and boiler steam utilization, while reducing steam injection costs. Furthermore, the method can lower the temperature of produced fluid from SAGD wells during the circulation phase, thereby reducing the cost of cooling and heat exchange loads at the terminal processing station.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield exploitation and production, and is a method and device for producing super-heavy oil in a SAGD production mode through a circulating series connection. Background Art

[0002] SAGD is an oil production method used to exploit heavy oil reservoirs, especially the development of extra-heavy oil reservoirs. SAGD production wells usually adopt a double horizontal well layout. The horizontal sections of the double horizontal wells are spaced 5 to 8 meters apart in the vertical direction. The upper horizontal well is used for steam injection, which heats the heavy oil in the reservoir near the horizontal section to reduce its viscosity. The steam flows to the lower horizontal well under the action of gravity. The lower horizontal well extracts the crude oil from the ground by means of self-flowing or mechanical extraction.

[0003] The SAGD production model will be in a circulation preheating stage for a period of time in the early stages of production. Its function is to connect the channels between the two horizontal wells to the greatest extent possible, so as to maximize the output during the normal production stage. During the circulation preheating stage, because the oil flow channel has not yet been formed, the output of the lower horizontal well contains steam injected from the well and a large number of upper horizontal wells. Since the injected steam is usually superheated steam, this steam has a high temperature and high enthalpy value. About 90% of the injected superheated steam is produced to the ground along with the oil fluid after circulation. The produced fluid temperature is above 200°C, and the residual enthalpy value is high. This output brings great problems to the terminal oil and gas processing. Not only does it require a large amount of water for heat exchange and cooling of the produced fluid, but it is also difficult to separate the oil and water emulsification under high saturation conditions. Therefore, it is necessary to develop a new production process to improve the production capacity and speed of oilfield production. Summary of the Invention

[0004] The present invention provides a method and apparatus for producing super-heavy oil in a circulating series under the SAGD production mode, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the existing problems in SAGD production of super-heavy oil fields, such as high temperature of the produced fluid in the circulating preheating stage, difficulty in oil-water separation at the end of the produced fluid, and high steam consumption cost.

[0005] One of the technical solutions of the present invention is achieved through the following measures: a super-heavy oil circulation series production method under the SAGD production mode is carried out according to the following steps: first, superheated steam from the boiler is injected into well P and well I of the A well group through the boiler steam main pipeline and the A well group main steam injection pipeline to heat the heavy oil in well P of the A well group; second, high-temperature produced fluid from well P of the A well group is injected into well P and well I of the B well group through the first liquid outlet pipeline, the B well group main steam injection pipeline and the third steam injection pipeline to heat the heavy oil in well P of the B well group; third, the produced fluid from well P of the B well group is discharged and sent to a processing station for treatment.

[0006] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions:

[0007] In the above two steps, the temperature of the high-temperature produced fluid from well P of well group A is 200°C to 300°C.

[0008] The second technical solution of the present invention is achieved by the following measures: a device for implementing the super-heavy oil circulation series production method under the SAGD production mode, comprising a well P of the A well group, a well I of the A well group, a well P of the B well group, a well I of the B well group, and a boiler steam main pipeline, the boiler steam main pipeline is fixedly connected with the A well group total steam injection pipeline and the B well group total steam injection pipeline from top to bottom, a first steam injection pipeline is fixedly connected between the outlet of the A well group total steam injection pipeline and the inlet of the P well of the A well group, a first liquid outlet pipeline is fixedly connected between the outlet of the P well of the A well group and the total steam injection pipeline of the B well group, the first steam injection pipeline and the boiler steam main pipeline are fixedly connected. A second steam injection pipeline is fixedly connected between the total steam injection line of the A well group and the inlet of the I well of the A well group between the steam main pipelines, a second liquid outlet pipeline is fixedly connected between the outlet of the I well of the A well group and the first liquid outlet pipeline, a third steam injection pipeline is fixedly connected between the outlet of the total steam injection line of the B well group and the inlet of the P well of the B well group, the outlet of the P well of the B well group is fixedly connected to the third liquid outlet pipeline, a fourth steam injection pipeline is fixedly connected between the total steam injection pipeline of the B well group and the inlet of the I well of the B well group between the third steam injection pipeline and the first liquid outlet pipeline, and a fourth liquid outlet pipeline is fixedly connected between the outlet of the I well of the B well group and the third liquid outlet pipeline.

[0009] The following is a further optimization and / or improvement of the second technical solution of the above invention:

[0010] A first connecting pipeline is fixedly connected between the first steam injection pipeline and the second liquid outlet pipeline and the first liquid outlet pipeline between the P well of the A well group, and a second connecting pipeline is fixedly connected between the fourth liquid outlet pipeline and the third liquid outlet pipeline between the P well of the B well group and the third steam injection pipeline.

[0011] A first bypass line is fixedly connected between the first connecting pipeline and the total steam injection line of the A well group and the first steam injection line between the first connecting pipeline and the P well of the A well group. A second bypass line is fixedly connected between the second steam injection line and the second liquid outlet line. A third bypass line is fixedly connected between the third steam injection line between the second connecting pipeline and the total steam injection line of the B well group and the third steam injection line between the second connecting pipeline and the P well of the B well group. A fourth bypass line is fixedly connected between the fourth steam injection line and the fourth liquid outlet line.

[0012] A first two-well connecting pipeline is fixedly connected between the second steam injection pipeline between the second bypass pipeline and well I of well group A and the first steam injection pipeline between the first bypass pipeline and well P of well group A; a second two-well connecting pipeline is fixedly connected between the fourth steam injection pipeline between the fourth bypass line and well I of well group B and the third steam injection pipeline between the third bypass line and well P of well group B.

[0013] A third connecting pipeline is fixedly connected between the first two-well connecting pipeline and the first steam injection pipeline between the P well of the A well group and the first liquid outlet pipeline between the first connecting pipeline and the second liquid outlet pipeline. A fourth connecting pipeline is fixedly connected between the second two-well connecting pipeline and the third steam injection pipeline between the P well of the B well group and the third liquid outlet pipeline between the second connecting pipeline and the fourth liquid outlet pipeline. A fifth connecting pipeline is fixedly connected between the first two-well connecting pipeline and the second steam injection pipeline between the I well of the A well group and the first liquid outlet pipeline between the second liquid outlet pipeline and the total steam injection pipeline of the B well group. A sixth connecting pipeline is fixedly connected between the second two-well connecting pipeline and the I well of the B well group and the fourth steam injection pipeline and the third liquid outlet pipeline between the outlet of the third liquid outlet pipeline.

[0014] The above-mentioned A well group main steam injection pipeline is fixedly installed with the A well group main steam injection valve, and the B well group main steam injection pipeline is fixedly installed with the B well group main steam injection valve.

[0015] The first steam injection pipeline between the above-mentioned first bypass pipeline and the P well of the A well group, the third steam injection pipeline between the third bypass pipeline and the P well of the B well group are all fixedly installed with the P well flowmeter inlet valve, P well flowmeter, P well flowmeter outlet valve, P well auxiliary pipe steam injection valve, pressure monitor and temperature monitor from left to right. The first connecting pipeline and the second connecting pipeline are both fixedly installed with the P well main pipe steam injection valve. The first bypass pipeline and the third bypass pipeline are both fixedly installed with the P well flowmeter bypass valve. The second bypass pipeline and the fourth bypass pipeline are both fixedly installed with the I well flowmeter bypass valve and the I well main pipe steam injection valve from left to right. The second steam injection pipeline between the second bypass pipeline and the I well of the A well group, and the fourth steam injection pipeline between the fourth bypass pipeline and the I well of the B well group are all fixedly installed from left to right. The I-well flowmeter inlet valve, I-well flowmeter, I-well flowmeter outlet valve, I-well auxiliary pipe steam injection valve, pressure monitor and temperature monitor are fixedly installed; the first two-well connecting pipeline and the second two-well connecting pipeline are fixedly installed with two-well connecting valves; the first liquid outlet pipeline and the third liquid outlet pipeline between the first connecting pipeline and the second liquid outlet pipeline are fixedly installed with temperature monitors, pressure monitors and P-well main pipe back-pressure valves from right to left; the third connecting pipeline and the fourth connecting pipeline are fixedly installed with P-well auxiliary pipe back-pressure valves; the second liquid outlet pipeline and the fourth liquid outlet pipeline between the second bypass pipeline and the first liquid outlet pipeline are fixedly installed with temperature monitors, pressure monitors and I-well main pipe back-pressure valves from right to left; the fifth connecting pipeline and the sixth connecting pipeline are fixedly installed with I-well auxiliary pipe back-pressure valves.

[0016] An atmospheric vent line is fixedly connected to the A well group main steam injection pipeline between the A well group steam injection main valve and the boiler steam main pipeline, and a vent valve is fixedly installed on the atmospheric vent pipeline. A first valve is fixedly installed on the boiler steam main pipeline between the boiler steam main pipeline inlet and the A well group main steam injection pipeline. A second valve and a third valve are fixedly installed in sequence from top to bottom on the boiler steam main pipeline between the A well group main steam injection pipeline and the B well group main steam injection pipeline. A fourth valve is fixed on the A well group main steam injection pipeline between the atmospheric vent line and the boiler steam main pipeline. A fifth valve is fixed on the B well group main steam injection pipeline between the first liquid outlet pipeline and the boiler steam main pipeline. A sixth valve and a seventh valve are fixedly installed in sequence from top to bottom on the first liquid outlet pipeline between the fifth connecting pipeline and the B well group main steam injection pipeline.

[0017] The present invention can effectively increase the number of wells opened, crude oil production and boiler steam utilization, reduce steam injection costs, and simultaneously reduce the temperature of the produced fluid in the SAGD well circulation stage, thereby reducing the cost of cooling and heat exchange loads at the terminal processing station. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attachment Figure 1 This is a schematic diagram of the process flow of Example 3 of the present invention.

[0019] Attachment Figure 2 This is a downhole schematic diagram of the SAGD well group in the present invention.

[0020] Attachment Figure 1The codes are as follows: 1 for P well of A well group, 2 for I well of A well group, 3 for P well of B well group, 4 for I well of B well group, 5 for main steam pipeline of boiler, 6 for total steam injection pipeline of A well group, 7 for total steam injection pipeline of B well group, 8 for first steam injection pipeline, 9 for first liquid discharge pipeline, 10 for second steam injection pipeline, 11 for second liquid discharge pipeline, 12 for third steam injection pipeline, 13 for third liquid discharge pipeline, 14 for fourth steam injection pipeline, 15 for fourth liquid discharge pipeline, 16 for fifth liquid discharge pipeline, 17 for sixth liquid discharge pipeline, 18 for eighth liquid discharge pipeline, 19 for eighth liquid discharge pipeline, 20 for eighth liquid discharge pipeline, 21 for eighth liquid discharge pipeline, 22 for eighth liquid discharge pipeline, 23 for eighth liquid discharge pipeline, 24 for eighth liquid discharge pipeline, 25 for eighth liquid discharge pipeline, 26 for eighth liquid discharge pipeline, 27 for eighth liquid discharge pipeline, 28 for eighth liquid discharge pipeline, 29 for eighth liquid discharge pipeline, 30 for eighth liquid discharge pipeline, 31 for eighth liquid discharge pipeline, 32 for eighth liquid discharge pipeline, 33 for eighth liquid discharge pipeline, 34 for eighth liquid discharge pipeline, 35 for eighth liquid discharge pipeline, 36 for eighth liquid discharge pipeline, 37 for eighth liquid discharge pipeline, 38 for eighth liquid discharge pipeline, 39 for eighth liquid discharge pipeline, 40 for eighth liquid discharge pipeline, 41 for eighth liquid discharge pipeline, 42 for eighth liquid discharge pipeline, 43 for eighth liquid discharge pipeline, 44 for eighth liquid discharge pipeline, 45 for eighth liquid discharge pipeline, 46 for eighth liquid discharge pipeline, 47 for eighth liquid discharge pipeline, 48 for eighth liquid discharge pipeline, 49 for eighth liquid discharge pipeline, 50 for eighth liquid discharge pipeline, 51 for eighth liquid discharge pipeline, 52 for eighth liquid discharge pipeline, 53 for eighth liquid discharge pipeline, 54 for eighth liquid discharge pipeline, 55 for eighth liquid discharge pipeline, 5 There are four liquid outlet pipelines, 16 is the first connecting pipeline, 17 is the second connecting pipeline, 18 is the first bypass pipeline, 19 is the second bypass pipeline, 20 is the third bypass pipeline, 21 is the fourth bypass pipeline, 22 is the first two-well connecting pipeline, 23 is the second two-well connecting pipeline, 24 is the third connecting pipeline, 25 is the fourth connecting pipeline, 26 is the fifth connecting pipeline, 27 is the sixth connecting pipeline, 28 is the main steam injection valve of well group A, 29 is the main injection valve of well group B. Steam main valve, 30 is the P well flow meter inlet valve, 31 is the P well flow meter, 32 is the P well flow meter outlet valve, 33 is the P well auxiliary pipe steam injection valve, 34 is the pressure monitor, 35 is the temperature monitor, 36 is the P well main pipe steam injection valve, 37 is the P well flow meter bypass valve, 38 is the I well flow meter bypass valve, 39 is the I well flow meter inlet valve, 40 is the I well flow meter, 41 is the I well flow meter outlet valve, 42 is the I well auxiliary pipe Steam injection valve, 43 is the two-well connecting valve, 44 is the P well main pipe back pressure valve, 45 is the P well auxiliary pipe back pressure valve, 46 is the I well main pipe back pressure valve, 47 is the I well auxiliary pipe back pressure valve, 48 is the atmospheric venting pipeline, 49 is the venting valve, 50 is the first valve, 51 is the second valve, 52 is the third valve, 53 is the fourth valve, 54 is the fifth valve, 55 is the sixth valve, 56 is the seventh valve, and 57 is the I well main pipe steam injection valve. DETAILED DESCRIPTION

[0021] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0022] The present invention will be further described below in conjunction with the embodiments:

[0023] Example 1: As shown in the attached Figure 1 As shown, the super-heavy oil circulation series production method under the SAGD production mode is carried out according to the following steps: First, superheated steam from the boiler is injected into well P1 and well I2 of the A-well group through the boiler steam main pipeline 5 and the A-well group main steam injection pipeline 6 to heat the heavy oil in well P1 of the A-well group; Second, the high-temperature produced fluid from well P1 of the A-well group is injected into well P3 and well I4 of the B-well group through the first liquid outlet pipeline 9, the B-well group main steam injection pipeline 7 and the third steam injection pipeline 12 to heat the heavy oil in well P3 of the B-well group; Third, the produced fluid from well P3 of the B-well group is discharged and sent to a processing station for treatment.

[0024] Example 2: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, in the second step, the temperature of the high-temperature produced fluid from well P1 of well group A is 200°C to 300°C.

[0025] The present invention utilizes the characteristics of high temperature, high pressure and high residual heat enthalpy of the produced fluid in the SAGD circulation preheating stage to inject the produced fluid into other wells for circulation preheating, thereby improving the commissioning progress and production speed of the newly built production capacity without adding new production capacity investment.

[0026] Example 3: The device for implementing the super-heavy oil circulation series production method under the SAGD production mode includes: A well group P well 1, A well group I well 2, B well group P well 3, B well group I well 4, and a boiler steam main pipeline 5. The boiler steam main pipeline 5 is fixedly connected to the A well group main steam injection pipeline 6 and the B well group main steam injection pipeline 7 from top to bottom. A first steam injection pipeline 8 is fixedly connected between the outlet of the A well group main steam injection pipeline 6 and the inlet of the A well group P well 1. A first liquid outlet pipeline 9 is fixedly connected between the outlet of the A well group P well 1 and the B well group main steam injection pipeline 7. The A well group main steam injection pipeline between the first steam injection pipeline 8 and the boiler steam main pipeline 5 is fixedly connected. A second steam injection pipeline 10 is fixedly connected between line 6 and the inlet of well 12 of group A wells, a second liquid outlet pipeline 11 is fixedly connected between the outlet of well 12 of group A wells and the first liquid outlet pipeline 9, a third steam injection pipeline 12 is fixedly connected between the outlet of the total steam injection pipeline 7 of group B wells and the inlet of well 3 of group B wells P, a third liquid outlet pipeline 13 is fixedly connected to the outlet of well 3 of group B wells P, a fourth steam injection pipeline 14 is fixedly connected between the third steam injection pipeline 12 and the first liquid outlet pipeline 9, and a fourth liquid outlet pipeline 15 is fixedly connected between the outlet of well 14 of group B wells I and the third liquid outlet pipeline 13.

[0027] Example 4: As an optimization of the above example 3, as shown in the attached Figure 1 As shown, a first connecting pipeline 16 is fixedly connected between the first steam injection pipeline 8 and the second liquid outlet pipeline 11 and the first liquid outlet pipeline 9 between the A well group P well 1, and a second connecting pipeline 17 is fixedly connected between the fourth liquid outlet pipeline 15 and the third liquid outlet pipeline 13 between the B well group P well 3 and the third steam injection pipeline 12.

[0028] Example 5: As an optimization of the above embodiment, as shown in the attached Figure 1As shown, a first bypass line 18 is fixedly connected between the first connecting line 16 and the first steam injection line 8 between the total steam injection line 6 of the A well group and the first steam injection line 8 between the first connecting line 16 and the P well 1 of the A well group, a second bypass line 19 is fixedly connected between the second steam injection line 10 and the second liquid outlet line 11, a third bypass line 20 is fixedly connected between the third steam injection line 12 between the second connecting line 17 and the total steam injection line 7 of the B well group and the third steam injection line 12 between the second connecting line 17 and the P well 3 of the B well group, and a fourth bypass line 21 is fixedly connected between the fourth steam injection line 14 and the fourth liquid outlet line 15.

[0029] According to the actual needs of the production site, whether well group A and well group B need additional steam injection and the amount of additional steam injection can be checked, and the valves on the first bypass line 18, the second bypass line 19, the third bypass line 20 and the fourth bypass line 21 can be flexibly adjusted to ensure the circulation effect of the SAGD well.

[0030] Example 6: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a first two-well connecting pipeline 22 is fixedly connected between the second bypass line 19 and the second steam injection pipeline 10 between the well I 2 of the well group A and the first steam injection pipeline 8 between the first bypass line 18 and the well P 1 of the well group A, and a second two-well connecting pipeline 23 is fixedly connected between the fourth bypass line 21 and the fourth steam injection pipeline 14 between the well I 4 of the well group B and the third bypass line 20 and the third steam injection pipeline 12 between the well P 3 of the well group B.

[0031] Example 7: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a third connecting pipeline 24 is fixedly connected between the first two-well connecting pipeline 22 and the first steam injection pipeline 8 between P well 1 of the A well group and the first connecting pipeline 16 and the first liquid outlet pipeline 9 between the second liquid outlet pipeline 11; a fourth connecting pipeline 25 is fixedly connected between the second two-well connecting pipeline 23 and the third steam injection pipeline 12 between P well 3 of the B well group and the second connecting pipeline 17 and the third liquid outlet pipeline 13 between the fourth liquid outlet pipeline 15; a fifth connecting pipeline 26 is fixedly connected between the first two-well connecting pipeline 22 and the second steam injection pipeline 10 between I well 2 of the A well group and the second liquid outlet pipeline 11 and the first liquid outlet pipeline 9 between the total steam injection pipeline 7 of the B well group; a sixth connecting pipeline 27 is fixedly connected between the second two-well connecting pipeline 23 and the fourth steam injection pipeline 14 between I well 4 of the B well group and the third liquid outlet pipeline 13 between the fourth liquid outlet pipeline 15 and the outlet of the third liquid outlet pipeline 13.

[0032] Example 8: As an optimization of the above embodiment, as shown in the attached Figure 1As shown, the A well group main steam injection valve 28 is fixedly installed on the A well group main steam injection pipeline 6, and the B well group main steam injection valve 29 is fixedly installed on the B well group main steam injection pipeline 7.

[0033] Example 9: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the first steam injection pipeline 8 between the first bypass pipeline 18 and the P well 1 of the A well group, and the third steam injection pipeline 12 between the third bypass pipeline 20 and the P well 3 of the B well group are fixedly installed with the P well flow meter inlet valve 30, the P well flow meter 31, the P well flow meter outlet valve 32, the P well auxiliary pipe steam injection valve 33, the pressure monitor 34 and the temperature monitor 35 from left to right. The first connecting pipeline 16 and the second connecting pipeline 17 are fixedly installed with the P well main pipe steam injection valve The first bypass line 18 and the third bypass line 20 are both fixedly installed with a P well flow meter bypass valve 37. The second bypass line 19 and the fourth bypass line 21 are both fixedly installed with a I well flow meter bypass valve 38 and an I well main steam injection valve 57 from left to right. The second bypass line 19 and the second steam injection line 10 between the second bypass line 19 and the well 2 of the A well group, and the fourth bypass line 21 and the fourth steam injection line 14 between the well 4 of the B well group are both fixedly installed from left to right. Equipped with a well flow meter inlet valve 39, a well flow meter 40, a well flow meter outlet valve 41, a well auxiliary pipe steam injection valve 42, a pressure monitor 34 and a temperature monitor 35. The first two-well connecting pipeline 22 and the second two-well connecting pipeline 23 are both fixedly installed with a two-well connecting valve 43. The first liquid outlet pipeline 9 and the third liquid outlet pipeline 13 between the first connecting pipeline 16 and the second liquid outlet pipeline 11 are fixedly installed with a temperature monitor 35, a pressure monitor 35 and a pressure monitor 35 in sequence from right to left. 34 and the P well main pipe back pressure valve 44, the third connecting pipeline 24 and the fourth connecting pipeline 25 are both fixedly installed with the P well auxiliary pipe back pressure valve 45, the second liquid outlet pipeline 11 and the fourth liquid outlet pipeline 15 between the second bypass pipeline 19 and the first liquid outlet pipeline 9 are both fixedly installed with a temperature monitor 35, a pressure monitor 34 and the I well main pipe back pressure valve 46, and the fifth connecting pipeline 26 and the sixth connecting pipeline 27 are both fixedly installed with the I well auxiliary pipe back pressure valve 47.

[0034] Example 10: As an optimization of the above embodiment, as shown in the attached Figure 1As shown, an atmospheric vent line 48 is fixedly connected to the A-well group main steam injection pipeline 6 between the A-well group steam injection main valve 28 and the boiler steam main pipeline 5, and a vent valve 49 is fixedly installed on the atmospheric vent pipeline 48. A first valve 50 is fixedly installed on the boiler steam main pipeline 5 between the boiler steam main pipeline 5 inlet and the A-well group main steam injection pipeline 6. From top to bottom, the boiler steam main pipeline 5 between the A-well group main steam injection pipeline 6 and the B-well group main steam injection pipeline 7 is connected to the atmospheric vent line 48. A second valve 51 and a third valve 52 are fixedly installed, a fourth valve 53 is fixed on the A well group total steam injection pipeline 6 between the atmospheric venting pipeline 48 and the boiler steam main pipeline 5, a fifth valve 54 is fixed on the B well group total steam injection pipeline 7 between the first liquid outlet pipeline 9 and the boiler steam main pipeline 5, and a sixth valve 55 and a seventh valve 56 are fixedly installed in sequence from top to bottom on the first liquid outlet pipeline 9 between the fifth connecting pipeline 26 and the B well group total steam injection pipeline 7.

[0035] In the present invention, unless otherwise specified, the equipment and devices used are all publicly known equipment and devices in the art.

[0036] As needed, conventional valves, thermometers, pressure gauges, etc. known and used in the art may be installed on the pipelines and equipment of the device implementing the super-heavy oil circulation serial production method under the SAGD production mode according to production needs.

[0037] In the present invention, the method for using the device for implementing the super-heavy oil circulation series production method under the SAGD production mode is as follows:

[0038] First, close the second valve 51, the third valve 52 on the boiler steam main line 5 and the fifth valve 54 on the B well group main steam injection line 7, close the P well main steam injection valve 36 on the first connecting line 16, close the P well flow meter bypass valve 37 on the first bypass line 18, close the I well flow meter bypass valve 38 and the I well main steam injection valve 57 on the second bypass line 19, close the P well auxiliary pipe back pressure valve 45 on the third connecting line 24 and the fourth connecting line 25, close the I well auxiliary pipe back pressure valve 47 on the fifth connecting line 26 and the sixth connecting line 27, and the steam from the boiler A portion of the superheated steam from the boiler steam main line 5 is injected into well I 2 of the A well group through the A well group main steam injection line 6 and the second steam injection line 10, and the other portion is injected into well P 1 of the A well group through the A well group main steam injection line 6 and the first steam injection line 8 (i.e., through the A well group steam injection main valve 28, the P well flow meter inlet valve 30, the P well flow meter 31, the P well flow meter outlet valve 32 and the P well auxiliary pipe steam injection valve 33 in sequence); then, the P well main steam injection valve 36 on the second connecting line 17 is closed, the P well flow meter bypass valve 37 on the third bypass line 20 is closed, and the fourth bypass line 2 is closed. 1. The bypass valve 38 of the flow meter of well I and the steam injection valve 57 of the main pipe of well I are connected. The produced liquid of well I 2 in the A well group is sent to the first liquid outlet line 9 through the second liquid outlet line 11 (i.e., it passes through the temperature monitor 35, the pressure monitor 34 and the back pressure valve 46 of the main pipe of well I in sequence). It is then combined with the produced liquid of well P 1 in the A well group (i.e., it passes through the temperature monitor 35, the pressure monitor 34 and the back pressure valve 44 of the main pipe of well P in sequence) and then enters the main steam injection line 7 of the B well group. Then, part of the produced liquid in the main steam injection line 7 of the B well group is injected into well I 4 in the B well group through the fourth steam injection line 14, and the other part is injected into the main steam injection line 7 of the B well group through the third steam injection line 14. Steam is injected into Well P3 of the B well group through the steam pipeline 12 (i.e., sequentially through the B well group steam injection main valve 29, the P well flowmeter inlet valve 30, the P well flowmeter 31, the P well flowmeter outlet valve 32, and the P well auxiliary pipe steam injection valve 33). Finally, the produced fluid from Well I4 of the B well group is sent to the third liquid outlet pipeline 13 through the fourth liquid outlet pipeline 15 (i.e., sequentially through the temperature monitor 35, the pressure monitor 34, and the I well main pipe back-pressure valve 46), where it is combined with the produced fluid from Well P3 of the B well group (i.e., sequentially through the temperature monitor 35, the pressure monitor 34, and the P well main pipe back-pressure valve 44) and sent to the processing station for treatment.

[0039] Example 11: As shown in the attached Figure 1 As shown, the super-heavy oil circulation series production method under the SAGD production mode is carried out according to the following steps:

[0040] Step 1: After wells are laid out in the SAGD block, two adjacent well groups are selected as a series of wells, and the design numbers are well group A and well group B (the downhole schematic diagram of SAGD well group A and well group B is shown in the figure below). Figure 2 As shown, the upper one is the steam injection well, i.e., well I, and the lower one is the oil production well, i.e., well P);

[0041] Step 2: Connect the serial connection process (the process needs to have inlet and outlet valves that control the A and B well groups respectively). Through the serial connection process, the circulating produced fluid of the A well group is connected to the inlet of the third steam injection pipeline 12 of the B well group through the first liquid outlet pipeline 9 and the main steam injection pipeline 7 of the B well group;

[0042] Step 3: First, steam is injected into the A-well group for circulation. After the A-well group circulation system is established and the outlet liquid temperature reaches the injection requirement, the established series connection process is opened, and the first outlet liquid pipeline 9 of the A-well group is connected to the third steam injection pipeline 12 of the B-well group. The high-temperature output liquid of the A-well enters the horizontal section of the B-well group, is mixed with the output liquid of the B-well group, and is transported to the processing station through the third outlet liquid pipeline 13 of the B-well group for treatment.

[0043] Step 4: After the circulation system is established in the B well group, the circulation quality of the A and B well groups is continuously monitored, and the downhole temperature is used to timely determine the downhole connectivity status of the SAGD during the circulation phase;

[0044] Step 5: After Wells A and B are confirmed to be connected, they will enter the next mechanical mining stage respectively. The established serial connection process can be dismantled at any time and retained until the next time the serial connection process is needed.

[0045] In the present invention's method and apparatus for producing ultra-heavy oil in a cascaded, circulating SAGD production mode, it is crucial to ensure that the steam injected from the boiler is superheated, maintaining a certain level of superheat. After the superheated steam enters the A well group circulation, the produced fluid carries a relatively high enthalpy, allowing it to maintain a high temperature after injection into the B well group. This is the only way to achieve a preheating effect on the B well circulation. If the heat output of the produced fluid from the A well group does not meet the B well circulation requirements, the second and third valves 51 and 52 on the boiler steam main line 5 and the fifth valve 54 on the B well group main steam injection line 7 can be opened as needed, and a small amount of additional steam can be injected through a flow meter to ensure effective B well circulation.

[0046] In summary, the present invention can effectively increase the number of wells opened, crude oil production and boiler steam utilization, reduce the cost of steam injection, and at the same time lower the temperature of the produced fluid in the circulation stage of the SAGD well, thereby reducing the cost of cooling and heat exchange loads at the terminal processing station.

[0047] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

Claims

1. A super heavy oil circulation series production method under SAGD production mode, characterized in that Follow the steps below: In the first step, superheated steam from the boiler is injected into well P and well I of well group A through the boiler steam main pipeline and the main steam injection pipeline of well group A to heat the heavy oil in well P of well group A. In the second step, the high-temperature produced fluid from well P of group A is injected into well P of group B and well I of group B via the first liquid outlet pipeline, the main steam injection pipeline of group B, the third steam injection pipeline, and the fourth steam injection pipeline, respectively, to heat the heavy oil in well P of group B. Taking advantage of the high temperature, high pressure, and high residual enthalpy of the produced fluid during the SAGD cycle preheating stage, the produced fluid is injected into well P of group A and well P of group B for circulation preheating. The temperature of the high-temperature produced fluid from well P of group A is between 200°C and 300°C. In the third step, the produced fluid from well P in group B is discharged and sent to the processing station for treatment. Well I is a steam injection well and well P is an oil production well. The apparatus for implementing the ultra-heavy oil circulating serial production method under the SAGD production mode includes P well of the A well group, I well of the A well group, P well of the B well group, I well of the B well group, a boiler steam main pipeline, and a first liquid outlet pipeline. The boiler steam main pipeline is directly connected to the A well group main steam injection pipeline and the B well group main steam injection pipeline, respectively. The first liquid outlet pipeline is directly connected to the B well group main steam injection pipeline, and the B well group main steam injection pipeline is directly connected to the third steam injection pipeline and the fourth steam injection pipeline, respectively.

2. The super-heavy oil circulation series production method under the SAGD production mode according to claim 1 is characterized in that The boiler steam main pipeline is fixedly connected with the A well group A main steam injection pipeline and the B well group B main steam injection pipeline from top to bottom. The first steam injection pipeline is fixedly connected between the outlet of the A well group A main steam injection pipeline and the inlet of well P of well group A. The first liquid outlet pipeline is fixedly connected between the outlet of well P of well group A and the main steam injection pipeline of well group B. The second steam injection pipeline is fixedly connected between the main steam injection pipeline of well group A and the inlet of well I of well group A between the first steam injection pipeline and the boiler steam main pipeline. The second liquid outlet pipeline is fixedly connected between the outlet of well I of well group A and the first liquid outlet pipeline. The third steam injection pipeline is fixedly connected between the outlet of the B well group B main steam injection pipeline and the inlet of well P of well group B. The third liquid outlet pipeline is fixedly connected with the outlet of well P of well group B. The fourth steam injection pipeline is fixedly connected between the third steam injection pipeline and the first liquid outlet pipeline between the main steam injection pipeline of well group B and the inlet of well I of well group B. The fourth liquid outlet pipeline is fixedly connected between the outlet of well I of well group B and the third liquid outlet pipeline.

3. The super-heavy oil circulation series production method under the SAGD production mode according to claim 2, characterized in that A first connecting pipeline is fixedly connected between the first steam injection pipeline and the second liquid outlet pipeline and the first liquid outlet pipeline between the P well of the A well group, and a second connecting pipeline is fixedly connected between the fourth liquid outlet pipeline and the third liquid outlet pipeline between the P well of the B well group and the third steam injection pipeline.

4. The method for producing super-heavy oil in a SAGD production mode according to claim 3, characterized in that A first bypass pipeline is fixedly connected between the first connecting pipeline and the total steam injection pipeline of the A well group and the first steam injection pipeline between the first connecting pipeline and the P well of the A well group. A second bypass pipeline is fixedly connected between the second steam injection pipeline and the second liquid outlet pipeline. A third bypass pipeline is fixedly connected between the third steam injection pipeline between the second connecting pipeline and the total steam injection pipeline of the B well group and the third steam injection pipeline between the second connecting pipeline and the P well of the B well group. A fourth bypass pipeline is fixedly connected between the fourth steam injection pipeline and the fourth liquid outlet pipeline.

5. The method for producing super-heavy oil in a SAGD production mode according to claim 4, characterized in that A first two-well connecting pipeline is fixedly connected between the second bypass line and the second steam injection pipeline between well I of well group A and the first steam injection pipeline between the first bypass line and well P of well group A. A second two-well connecting pipeline is fixedly connected between the fourth bypass line and well I of well group B and the third steam injection pipeline between the third bypass line and well P of well group B.

6. The method for producing super-heavy oil in a SAGD production mode according to claim 5, characterized in that A third connecting pipeline is fixedly connected between the first two-well connecting pipeline and the first steam injection pipeline between the P well of the A well group and the first liquid outlet pipeline between the first connecting pipeline and the second liquid outlet pipeline. A fourth connecting pipeline is fixedly connected between the second two-well connecting pipeline and the third steam injection pipeline between the P well of the B well group and the third liquid outlet pipeline between the second connecting pipeline and the fourth liquid outlet pipeline. A fifth connecting pipeline is fixedly connected between the first two-well connecting pipeline and the second steam injection pipeline between the I well of the A well group and the first liquid outlet pipeline between the second liquid outlet pipeline and the total steam injection pipeline of the B well group. A sixth connecting pipeline is fixedly connected between the second two-well connecting pipeline and the I well of the B well group and the fourth steam injection pipeline and the third liquid outlet pipeline between the fourth liquid outlet pipeline and the outlet of the third liquid outlet pipeline.

7. The method for producing super-heavy oil in a SAGD production mode in a circulating series manner according to any one of claims 1 to 6, characterized in that The A well group A steam injection main valve is fixedly installed on the A well group A steam injection pipeline, and the B well group B steam injection main valve is fixedly installed on the B well group B steam injection pipeline.

8. The method for producing super-heavy oil in a SAGD production mode according to claim 7, characterized in that The first steam injection pipeline between the first bypass pipeline and the P well of the A well group, the third steam injection pipeline between the third bypass pipeline and the P well of the B well group are all fixedly installed with the P well flow meter inlet valve, P well flow meter, P well flow meter outlet valve, P well auxiliary pipe steam injection valve, pressure monitor and temperature monitor from left to right. The first connecting pipeline and the second connecting pipeline are both fixedly installed with the P well main pipe steam injection valve. The first bypass pipeline and the third bypass pipeline are both fixedly installed with the P well flow meter bypass valve. The second bypass pipeline and the fourth bypass pipeline are both fixedly installed with the I well flow meter bypass valve and the I well main pipe steam injection valve from left to right. The second steam injection pipeline between the second bypass pipeline and the I well of the A well group, and the fourth steam injection pipeline between the fourth bypass pipeline and the I well of the B well group are all fixedly installed from left to right. It is equipped with an inlet valve of the I-well flowmeter, an I-well flowmeter, an outlet valve of the I-well flowmeter, a steam injection valve of the I-well auxiliary pipe, a pressure monitor and a temperature monitor. The first two-well connecting pipeline and the second two-well connecting pipeline are both fixedly installed with two-well connecting valves. The first liquid outlet pipeline and the third liquid outlet pipeline between the first connecting pipeline and the second liquid outlet pipeline are both fixedly installed with a temperature monitor, a pressure monitor and a P-well main pipe back-pressure valve from right to left. The third connecting pipeline and the fourth connecting pipeline are both fixedly installed with a P-well auxiliary pipe back-pressure valve. The second liquid outlet pipeline and the fourth liquid outlet pipeline between the second bypass pipeline and the first liquid outlet pipeline are both fixedly installed with a temperature monitor, a pressure monitor and a I-well main pipe back-pressure valve from right to left. The fifth connecting pipeline and the sixth connecting pipeline are both fixedly installed with an I-well auxiliary pipe back-pressure valve.

9. The method for producing super-heavy oil in a SAGD production mode according to claim 8, characterized in that An atmospheric vent line is fixedly connected to the A well group main steam injection pipeline between the A well group steam injection main valve and the boiler steam main pipeline, and a vent valve is fixedly installed on the atmospheric vent pipeline. A first valve is fixedly installed on the boiler steam main pipeline between the boiler steam main pipeline inlet and the A well group main steam injection pipeline. A second valve and a third valve are fixedly installed in sequence from top to bottom on the boiler steam main pipeline between the A well group main steam injection pipeline and the B well group main steam injection pipeline. A fourth valve is fixed on the A well group main steam injection pipeline between the atmospheric vent line and the boiler steam main pipeline. A fifth valve is fixed on the B well group main steam injection pipeline between the first liquid outlet pipeline and the boiler steam main pipeline. A sixth valve and a seventh valve are fixedly installed in sequence from top to bottom on the first liquid outlet pipeline between the fifth connecting pipeline and the B well group main steam injection pipeline.

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