High-sulfur heavy oil thermal recovery gathering and transportation treatment method and device

Abstract

The present application relates to the technical field of high-sulfur heavy oil development, and is a kind of high-sulfur heavy oil thermal recovery gathering and transportation treatment method and device, the former is carried out according to the following method: first, multi-element thermal fluid is injected into a single well through a pipeline, the single well is shut in for production, the produced liquid is subjected to gas-liquid separation and pressure boosting, associated gas and water-containing crude oil are separated, the water-containing crude oil is subjected to one-time temperature and pressure boosting and then gathered and transported to a treatment station, the associated gas enters an associated gas incinerator, high-temperature flue gas generated by incineration of the associated gas enters a waste heat recovery boiler to generate high-temperature steam; second, the water-containing crude oil enters the treatment station and is subjected to one-time dehydration, two-time temperature and pressure boosting, two-time dehydration and flash dehydration in sequence, and finally purified crude oil and produced water are separated. The present application realizes closed gathering and transportation and treatment process, reduces heat energy loss in the development process, and realizes high-temperature gathering and transportation and treatment by using heat energy recovered from self-produced associated gas of an oilfield.

Description

Technical Field

[0001] This invention relates to the field of high-sulfur heavy oil development technology, and is a gathering and transportation processing method and apparatus for the thermal recovery of high-sulfur heavy oil. Background Technology

[0002] High-sulfur heavy oil generally has a high sulfur content (4% to 6%) and a high density (1.02 g / cm³). 3 Up to 1.05 g / cm 3 It has the characteristics of high mineralization (>15000mg / L) and very close oil-water density. At present, cold production development is mostly adopted, and the process of "dilution reduction and viscosity reduction gathering and transportation at the wellhead, and dilution reduction and viscosity reduction dehydration at the treatment station" is selected.

[0003] As the dissolved gas content in the formation decreases and the viscosity of degassed crude oil increases, single-well production tends to decline, making it difficult to achieve stable production. Furthermore, the high operating costs of dilution blending, gathering, and processing technologies, coupled with high system energy consumption, lead to a sharp drop in overall oilfield development efficiency due to the combined effects of declining production and falling oil prices. After comparing various development methods, using thermal recovery to increase single-well production and achieve large-scale oilfield development has become the most important means of stabilizing and increasing production of sulfur-containing heavy oil.

[0004] Multi-element thermal fluid technology is a novel development method distinct from conventional steam thermal recovery. Utilizing rocket engine principles, fuel, air, and water undergo high-pressure combustion in a sealed combustion chamber, generating a multi-element fluid which is then injected into the formation, achieving more efficient development. However, multi-element thermal fluid development technology has not yet entered the stage of large-scale development, mainly due to the following constraints: First, the close proximity of oil and water densities in heavy oil makes gathering, transportation, and dehydration difficult. The high costs of dilution, gathering, and processing, along with the issue of diluent sourcing, are major factors restricting the large-scale and efficient development of heavy oil. Second, under high-temperature conditions during multi-component thermal recovery, hydrothermal cracking occurs, causing the breakage of CS bonds. This results in associated gas containing up to 80,000 ppm of hydrogen sulfide, 10% to 30% carbon dioxide, and a large amount of nitrogen, making the associated gas composition more complex and hindering its compliant treatment and resource utilization. Finally, the comprehensive utilization of thermal energy during the development, gathering, transportation, and processing of heavy oil presents significant challenges. On one hand, the gathering, transportation, and dehydration processes of heavy oil require substantial amounts of heat. While heavy oil has a high gas-to-oil ratio, the immature technologies for compliant treatment and resource utilization of complex sulfur-containing associated gas prevent its direct use as fuel in heating furnaces. Currently, it can only be ineffectively burned and released, failing to provide a heat source for heavy oil thermal recovery. Summary of the Invention

[0005] This invention provides a gathering and transportation processing method and apparatus for thermal recovery of high-sulfur heavy oil, which overcomes the shortcomings of the prior art and can effectively solve the problems of difficult gathering, transportation and dehydration, and excessively high processing costs in the development of multi-element thermal fluid heavy oil.

[0006] One of the technical solutions of this invention is achieved through the following measures: a gathering and transportation method for high-sulfur heavy oil thermal recovery, carried out according to the following method: The first step involves injecting a multi-component thermal fluid into a single well via pipeline. After the well is shut down, production begins. The produced fluid undergoes gas-liquid separation and pressurization to separate associated gas and water-bearing crude oil. The water-bearing crude oil is then transported to the processing station after a second heating and pressurization. The associated gas enters the associated gas incinerator, where it is incinerated to produce high-temperature flue gas, which then enters the waste heat recovery boiler to generate high-temperature steam. The second step involves the water-bearing crude oil undergoing a series of processes at the processing station: primary dehydration, secondary heating and pressurization, secondary dehydration, and flash dehydration. This process ultimately separates the purified crude oil and produced water. The primary heating and pressurization is achieved by adding high-temperature steam generated by the waste heat recovery boiler into the water-bearing crude oil.

[0007] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions: The aforementioned secondary heating and pressurization is carried out by adding high-temperature steam generated by a waste heat recovery boiler into the water-containing crude oil.

[0008] In the first step above, the pressure of the multi-element heat fluid is 8 MPa to 12 MPa, and the temperature is 320°C to 370°C.

[0009] The water in the aforementioned multi-component thermal fluid is provided by the produced water separated in the second step.

[0010] In the first step above, the water-containing crude oil is heated and pressurized once, and the temperature is 160°C to 200°C, and the pressure is 1.8MPa to 2.5MPa.

[0011] In the first step above, the water content of the crude oil is 25% to 35% after one dehydration.

[0012] In the second step mentioned above, the water-containing crude oil is heated and pressurized twice, with a temperature of 210°C to 230°C and a pressure of 1.8MPa to 2.5MPa.

[0013] In the second step mentioned above, the water content of the crude oil after secondary dehydration is 6% to 9%.

[0014] In the second step above, the water content of the purified crude oil that is finally separated after flash evaporation and dehydration is 0.5%.

[0015] The aforementioned high-temperature steam pressure is 2.5 to 5.0 MPa, and the temperature is 230°C to 260°C.

[0016] The second technical solution of the present invention is achieved through the following measures: an apparatus for a method of gathering and processing high-sulfur heavy oil thermal recovery, comprising a single well, a multi-element thermal fluid generator, a gas-liquid separation booster skid, an associated gas incinerator, a waste heat recovery boiler, and a high-temperature reverse-phase dehydrator. A multi-element thermal fluid pipeline is fixedly connected between the discharge end of the multi-element thermal fluid generator and the feed end of the single well. A single-well pipeline is fixedly connected between the discharge end of the single well and the first feed end of the gas-liquid separation booster skid. An oil pipeline is fixedly connected between the liquid outlet end of the gas-liquid separation booster skid and the feed end of the high-temperature reverse-phase dehydrator. A water supply pipeline is fixedly connected between the first discharge end of the reverse phase dehydrator and the feed end of the multi-element hot fluid generator. A purified crude oil export pipeline is fixedly connected between the second discharge end of the high-temperature reverse phase dehydrator. A gas transmission pipeline is fixedly connected between the gas outlet end of the gas-liquid separation booster skid and the feed end of the associated gas incinerator. A high-temperature flue gas pipeline is fixedly connected between the associated gas incinerator and the waste heat recovery boiler. A well site steam mixing pipeline is fixedly connected between the first discharge end of the waste heat recovery boiler and the oil transmission pipeline. A crude oil steam mixing pipeline is fixedly connected between the second discharge end of the waste heat recovery boiler and the high-temperature reverse phase dehydrator.

[0017] The following are further optimizations and / or improvements to the second technical solution of the above invention: The aforementioned gathering and processing unit for high-sulfur heavy oil thermal recovery also includes a desulfurization tower, and a desulfurization pipeline is fixedly connected between the associated gas incinerator and the desulfurization tower.

[0018] The gathering and processing method for high-sulfur heavy oil thermal recovery of the present invention realizes a closed-loop process for gathering, transportation and processing, reduces heat energy loss during development, and utilizes the heat energy recovered from associated gas produced by the oilfield to achieve high-temperature gathering, transportation and processing. While ensuring that the associated gas is discharged in compliance with standards, it reduces the overall energy consumption of oilfield development and meets the needs of green oilfield development under the new situation. Attached Figure Description

[0019] Appendix Figure 1 This is a schematic diagram of the process flow according to an embodiment of the present invention.

[0020] Appendix Figure 1 The codes are as follows: 1 for single well, 2 for multi-element thermal fluid generator, 3 for gas-liquid separation pressurization skid, 4 for associated gas incinerator, 5 for waste heat recovery boiler, 6 for high-temperature reverse phase dehydrator, 7 for multi-element thermal fluid pipeline, 8 for single well pipeline, 9 for oil pipeline, 10 for water supply pipeline, 11 for purified crude oil export pipeline, 12 for gas pipeline, 13 for high-temperature flue gas pipeline, 14 for well site steam blending pipeline, 15 for crude oil steam blending pipeline, 16 for desulfurization tower, and 17 for desulfurization pipeline. Detailed Implementation

[0021] This invention is not limited to the following embodiments; specific implementation methods can be determined according to the technical solution of this invention and actual conditions. Unless otherwise specified, all chemical reagents and chemical products mentioned in this invention are well-known and commonly used chemical reagents and chemical products in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent.

[0022] Unless otherwise specified, all equipment and devices used in this invention are existing and commonly known in the art.

[0023] The present invention will be further described below with reference to embodiments: Example 1: The gathering and transportation method for high-sulfur heavy oil thermal recovery is carried out according to the following steps: The first step involves injecting a multi-component thermal fluid into a single well (1) via pipeline. After well 1 is shut down, production commences. The produced fluid undergoes gas-liquid separation and pressurization to separate associated gas and water-bearing crude oil. The water-bearing crude oil undergoes a first heating and pressurization process before being transported to the processing station. The associated gas enters the associated gas incinerator (4), where it is incinerated to produce high-temperature flue gas, which then enters the waste heat recovery boiler (5) to generate high-temperature steam. The second step involves the water-bearing crude oil undergoing a first dehydration, a second heating and pressurization process, a second dehydration, and a flash dehydration process at the processing station, ultimately separating purified crude oil and produced water. The first heating and pressurization process is achieved by adding high-temperature steam generated by the waste heat recovery boiler (5) into the water-bearing crude oil.

[0024] Example 2: As an optimization of the above example, in the second step, the secondary heating and pressurization is carried out by adding high-temperature steam generated by the waste heat recovery boiler 5 into the water-containing crude oil.

[0025] Example 3: As an optimization of the above example, in the first step, the pressure of the multi-element heat fluid is 8MPa to 12MPa, and the temperature is 320°C to 370°C.

[0026] Example 4: As an optimization of the above example, the water in the multi-element thermal fluid is provided by the produced water separated in the second step.

[0027] Example 5: As an optimization of the above example, in the first step, the water-containing crude oil is heated and pressurized once, and the temperature is 160°C to 200°C, and the pressure is 1.8MPa to 2.5MPa.

[0028] Example 6: As an optimization of the above example, in the first step, the water content of the water-containing crude oil is 25% to 35% after one dehydration.

[0029] Example 7: As an optimization of the above example, in the second step, the water-containing crude oil is heated and pressurized twice to a temperature of 210°C to 230°C and a pressure of 1.8MPa to 2.5MPa.

[0030] Example 8: As an optimization of the above example, in the second step, the water content of the water-containing crude oil after secondary dehydration is 6% to 9%.

[0031] Example 9: As an optimization of the above example, in the second step, the water content of the purified crude oil that is finally separated after flash dehydration of the water-containing crude oil is 0.5%.

[0032] Example 10: As an optimization of the above example, the high-temperature steam pressure is 2.5 to 5.0 MPa and the temperature is 230°C to 260°C.

[0033] In this invention, the associated gas separated from the produced fluid (associated gas pressure is 1.2 MPa, temperature is 80 to 120°C) can be transported under pressure (gathering and transmission radius is 10 km to 15 km) through the gas transmission pipeline 12 to the associated gas incinerator 4 of the treatment station. When the gathering and transmission radius is greater than 15 km, the associated gas can be pressurized and transported to the associated gas incinerator 4 of the treatment station.

[0034] This invention has the following advantages: First, the heat energy required for gathering, transportation, and dehydration is provided by the combustion of associated gas, and the produced water is reused through the multi-element thermal fluid generator 2, realizing internal heating and water supply circulation within the gathering, transportation, and processing system. Second, this invention utilizes the system's waste heat to achieve high-temperature gathering and transportation without dilution, and high-temperature reverse-phase separation and dehydration, making it highly adaptable to heavy oil fields lacking diluents. Finally, through associated gas combustion and waste heat recovery, this invention achieves compliant discharge of complex associated gas with high sulfur content obtained through multi-element thermal fluid thermal recovery, reduces the heating load of the gathering, transportation, and processing system, reduces fuel gas consumption, and achieves energy reduction and carbon emission reduction.

[0035] Example 11: As Figure 1As shown, the apparatus for the gathering and processing method of high-sulfur heavy oil thermal recovery includes a single well 1, a multi-element thermal fluid generator 2, a gas-liquid separation booster skid 3, an associated gas incinerator 4, a waste heat recovery boiler 5, and a high-temperature reverse-phase dehydrator 6. A multi-element thermal fluid pipeline 7 is fixedly connected between the discharge end of the multi-element thermal fluid generator 2 and the feed end of the single well 1. A single well pipeline 8 is fixedly connected between the discharge end of the single well 1 and the first feed end of the gas-liquid separation booster skid 3. An oil pipeline 9 is fixedly connected between the liquid outlet end of the gas-liquid separation booster skid 3 and the feed end of the high-temperature reverse-phase dehydrator 6. The first discharge end of the high-temperature reverse-phase dehydrator 6 is connected to the multi-element thermal fluid generator 2. A water supply pipe 10 is fixedly connected to the feed end of the thermal fluid generator 2. A purified crude oil export pipe 11 is fixedly connected to the second discharge end of the high-temperature reverse phase dehydrator 6. A gas transmission pipe 12 is fixedly connected to the gas outlet end of the gas-liquid separation booster skid 3 and the feed end of the associated gas incinerator 4. A high-temperature flue gas pipeline 13 is fixedly connected to the associated gas incinerator 4 and the waste heat recovery boiler 5. A well site steam mixing pipeline 14 is fixedly connected to the first discharge end of the waste heat recovery boiler 5 and the oil transmission pipeline 9. A crude oil steam mixing pipeline 15 is fixedly connected to the second discharge end of the waste heat recovery boiler 5 and the high-temperature reverse phase dehydrator 6.

[0036] Example 12: As Figure 1 As shown, the gathering and processing device for high-sulfur heavy oil thermal recovery also includes a desulfurization tower 16, and a desulfurization pipeline 17 is fixedly connected between the associated gas incinerator 4 and the desulfurization tower 16.

[0037] Example 13: The gathering and transportation method for the thermal recovery of high-sulfur heavy oil is carried out according to the following steps: In the first step, the high-temperature, high-pressure multi-element thermal fluid (10MPa pressure, 350℃) generated by the multi-element thermal fluid generator 2 is injected into the single well 1 through the single well pipeline 8. After the single well 1 is shut down, production begins. The produced fluid (1.2MPa pressure, 80℃ to 120℃) enters the gas-liquid separation and pressurization skid 3 through the single well pipeline 8 for gas-liquid separation and pressurization. The separated associated gas (1.2MPa, 80℃ to 120℃) is transported by its own pressure through the gas transmission pipeline 12 to the associated gas incinerator 4 of the processing station. The separated water-containing crude oil (1.2MPa pressure, 80℃ to 120℃) is mixed with high-temperature steam (1.2MPa, 180℃) through the well site steam mixing pipeline 14, and the temperature and pressure are increased to 1.8 to 2.5MPa and 180℃ in one step.

[0038] The associated gas separated from the produced fluid (pressure 0.3 MPa, temperature 50℃) enters the associated gas incinerator 4 through the gas pipeline 12. After combustion, the associated gas produces high-temperature flue gas (pressure 0.3 MPa, temperature 800℃). The high-temperature flue gas enters the waste heat recovery boiler 5 to produce high-temperature steam (2.5 to 5.0 MPa, 250℃). Part of the high-temperature steam is transported to the well site through the well site steam blending pipeline 14 to heat the water-bearing crude oil to 180℃, ensuring high-temperature gathering and transportation of the water-bearing crude oil. The other part of the high-temperature steam is transported to the high-temperature reverse phase dehydrator 6 through the crude oil steam blending pipeline 15.

[0039] The second step involves transporting the water-containing crude oil through pipeline 9 to the processing station. After initial dehydration to a water content of 30%, it is then introduced into the crude oil via steam blending pipeline 15, where it is further heated and pressurized to a pressure of 1.8 to 2.5 MPa and a temperature of 220°C. This second pressurized and heated crude oil undergoes a second dehydration process in a high-temperature reverse-phase dehydrator 6, reducing the water content to 8%. It then enters a flash separator, where it is depressurized (1.0 to 0.5 MPa) and flash-dehydrated to a water content of 0.5%, yielding qualified purified crude oil (purified crude oil temperature 150°C) and produced water (produced water temperature 200°C). Heat is recovered through a heat exchange system to preheat the incoming water-containing crude oil.

[0040] Third, the extracted water separated in the second step enters the multi-element heat fluid generator 2 to generate multi-element heat fluid. In addition, the flue gas (0.2MPa, 120℃) generated by the waste heat boiler enters the desulfurization tower 16, and is discharged after being treated to meet the requirements.

[0041] The method of this invention achieves high-temperature gathering and transportation, expanding the gathering and transportation radius. Currently, domestic heavy oil thermal recovery has a low gas-oil ratio, and all methods use ambient temperature gathering and transportation, resulting in short gathering and transportation radii. Taking the development of heavy oil in Xinjiang Oilfield as an example, the gas-oil ratio is below 5:1, and the maximum self-pressurized gathering and transportation radius of a single well is 5km. Using multi-component thermal fluid development, the gas-oil ratio can reach 50:1, and the direct self-pressurized gathering and transportation radius of the produced fluid from a single well is no more than 1km. This invention achieves high-temperature gathering and transportation, which can expand the self-pressurized gathering and transportation radius to 10km. In addition, in existing processes, the dehydration time for domestic heavy oil large tank settling process is 96 hours, the dehydration time for high-temperature sealed process is 4 hours, and the dehydration time for foreign dilution process is 2 to 4 hours. The method of this invention, without dilution, achieves a dehydration time of 2 hours, which is a significant reduction compared to existing processes.

[0042] In summary, the gathering, transportation, and processing method for high-sulfur heavy oil thermal recovery of this invention achieves a closed-loop process throughout the entire process, reducing heat energy loss during development. It utilizes the heat energy recovered from associated gas produced in the oilfield to achieve high-temperature gathering, transportation, and processing. While ensuring the associated gas meets emission standards, it also reduces the overall energy consumption of oilfield development, meeting the demands of green oilfield development under the new circumstances. This invention represents a breakthrough in the field of gathering, transportation, and processing technology for multi-element thermal fluid recovery surface engineering, filling the technological gap in multi-element thermal fluid recovery surface engineering for high-sulfur heavy oil both domestically and internationally, and providing strong technical support for the large-scale application and promotion of high-sulfur heavy oil field development.

[0043] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A method for gathering, transporting, and processing high-sulfur heavy oil during thermal recovery, characterized in that... The process is as follows: First, a multi-component thermal fluid is injected into a single well through a pipeline. After the well is shut down, production begins. The produced fluid undergoes gas-liquid separation and pressurization to separate associated gas and water-bearing crude oil. The water-bearing crude oil is then transported to the processing station after a first heating and pressurization. The associated gas enters the associated gas incinerator, where it is incinerated to produce high-temperature flue gas, which then enters the waste heat recovery boiler to generate high-temperature steam. Second, the water-bearing crude oil undergoes a first dehydration, a second heating and pressurization, a second dehydration, and a flash dehydration process at the processing station, ultimately separating purified crude oil and produced water. The first heating and pressurization is achieved by adding high-temperature steam generated by the waste heat recovery boiler into the water-bearing crude oil. The secondary heating and pressurization is carried out by adding high-temperature steam generated by a waste heat recovery boiler into the water-containing crude oil; the water in the multi-element thermal fluid is provided by the produced water separated in the second step. The implementation apparatus for the gathering and transportation of high-sulfur heavy oil thermal recovery includes a single well, a multi-element thermal fluid generator, a gas-liquid separation booster skid, an associated gas incinerator, a waste heat recovery boiler, and a high-temperature reverse-phase dehydrator. A multi-element thermal fluid pipeline is fixedly connected between the discharge end of the multi-element thermal fluid generator and the feed end of the single well. A single-well pipeline is fixedly connected between the discharge end of the single well and the first feed end of the gas-liquid separation booster skid. An oil pipeline is fixedly connected between the liquid outlet end of the gas-liquid separation booster skid and the feed end of the high-temperature reverse-phase dehydrator. The first discharge end of the high-temperature reverse-phase dehydrator... A water supply pipeline is fixedly connected to the feed end of the multi-element hot fluid generator; a purified crude oil export pipeline is fixedly connected to the second discharge end of the high-temperature reverse phase dehydrator; a gas transmission pipeline is fixedly connected to the gas outlet end of the gas-liquid separation booster skid and the feed end of the associated gas incinerator; a high-temperature flue gas pipeline is fixedly connected to the associated gas incinerator and the waste heat recovery boiler; a well site steam mixing pipeline is fixedly connected to the first discharge end of the waste heat recovery boiler and the oil transmission pipeline; and a crude oil steam mixing pipeline is fixedly connected to the second discharge end of the waste heat recovery boiler and the high-temperature reverse phase dehydrator.

2. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 1, characterized in that... In the first step, the pressure of the multi-element heat fluid is 8 MPa to 12 MPa, and the temperature is 320°C to 370°C.

3. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 1 or 2, characterized in that... In the first step, the water-containing crude oil is heated and pressurized once to a temperature of 160°C to 200°C and a pressure of 1.8MPa to 2.5MPa; or / and, in the first step, the water-containing crude oil is dehydrated once to a water content of 25% to 35%.

4. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 1 or 2, characterized in that... In the second step, the water-containing crude oil is heated and pressurized twice to a temperature of 210°C to 230°C and a pressure of 1.8MPa to 2.5MPa; or / and, in the second step, the water-containing crude oil is dehydrated twice to a water content of 6% to 9%.

5. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 3, characterized in that... In the second step, the water-containing crude oil is heated and pressurized twice to a temperature of 210°C to 230°C and a pressure of 1.8MPa to 2.5MPa; or / and, in the second step, the water-containing crude oil is dehydrated twice to a water content of 6% to 9%.

6. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 1, 2, or 5, characterized in that... In the second step, the water-containing crude oil is flash-dehydrated and finally separated into purified crude oil with a water content of 0.5%; or / and, the high-temperature steam pressure is 2.5 to 5.0 MPa and the temperature is 230°C to 260°C.

7. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 3, characterized in that... In the second step, the water-containing crude oil is flash-dehydrated and finally separated into purified crude oil with a water content of 0.5%; or / and, the high-temperature steam pressure is 2.5 to 5.0 MPa and the temperature is 230°C to 260°C.

8. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 4, characterized in that... In the second step, the water-containing crude oil is flash-dehydrated and finally separated into purified crude oil with a water content of 0.5%; or / and, the high-temperature steam pressure is 2.5 to 5.0 MPa and the temperature is 230°C to 260°C.

9. The gathering and transportation method for high-sulfur heavy oil thermal recovery according to claim 1, characterized in that... The implementation device also includes a desulfurization tower, and a desulfurization pipeline is fixedly connected between the associated gas incinerator and the desulfurization tower.

Images