A low-energy-consumption and low-pollution-discharge sulfur-containing gas field water treatment coupling system
By using air or inert stripping and resource utilization methods, the problems of high cost and high pollution in sulfur-containing gas field water treatment have been solved, achieving low-energy consumption and low-pollution gas field water treatment, meeting environmental protection standards, and utilizing sulfur and gypsum as resources.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM ENG & CONSTR
- Filing Date
- 2024-11-29
- Publication Date
- 2026-05-29
AI Technical Summary
Existing water treatment processes for sulfur-containing gas fields suffer from high treatment costs, difficulty in achieving H2S standards in treated water, and difficulty in controlling pollutant emissions. In particular, in the treatment of water from large-scale gas fields with high sulfur content, existing processes are inefficient, energy-intensive, and cause serious pollution.
The H2S in the gas field water is stripped out using air or inert stripping methods and converted into sulfur or gypsum through resource utilization. Combined with static mixers, pH adjustment tanks, stripping towers and hydrogen sulfide treatment units, the process achieves low energy consumption and low pollution emissions, including a multi-stage absorption tower and oxidation regeneration tower.
It significantly reduced the cost of desulfurization treatment of gas field water, reduced pollutant emissions, met environmental protection standards, achieved compliance with emission standards for H2S and SO2, utilized sulfur and gypsum resources, and protected the environment.
Smart Images
Figure CN122102347A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of environmental protection technology in oil and gas fields, and in particular relates to a low-energy-consumption and low-pollution-emission coupling system for treating sulfur-containing gas field water. Background Technology
[0002] With the expansion of national energy demand, energy companies have increased their exploitation of natural gas reservoirs, leading to the development of more and more sulfur-containing and high-sulfur gas fields. In these sulfur-containing gas fields, the residual acid, condensate water, and formation water (collectively referred to as gas field water in this application) all contain high levels of sulfides, making the treatment of sulfur-containing gas field water increasingly difficult. As many domestic oil and gas fields enter the later stages of exploitation, the amount of produced water is also increasing year by year. In recent years, the approval process for produced water reinjection wells has become increasingly stringent, and new wastewater discharge standards are constantly raising the requirements for the treatment of produced water from oil and gas fields. If gas field water cannot be effectively treated, it will severely restrict gas field development. Proper treatment of produced water is one of the bottlenecks in natural gas development and enhanced oil recovery, especially given the occupational health, safety, and environmental problems associated with produced water from sulfur-containing gas fields. Due to the complex composition, high hydrogen sulfide content, and high pollutant concentrations of produced water from sulfur-containing gas fields, its treatment is extremely difficult. To ensure the proper treatment of sulfur-containing water, effective treatment processes are necessary to reduce the sulfide content while minimizing waste gas and residue generation to reduce environmental pollution. Improper treatment can pollute the environment, damage the ecosystem, and even endanger public safety. Therefore, ensuring low-energy consumption and low-pollution discharge of sulfur-containing gas field water is crucial.
[0003] The main processes currently used for treating sulfur-containing gas field water are chemical treatment or stripping with fuel gas, nitrogen, or steam. Chemical treatment of sulfur-containing gas field water has a simple process flow and can be used in gas field water with low hydrogen sulfide content and small-scale treatment operations. However, it consumes a large amount of chemicals, resulting in high production costs. Typically, treating 1 ton of sulfur requires approximately 100,000 yuan in chemical costs. It is more economical when the sulfur concentration in the gas field water is below 50 kg / d. Stripping with fuel gas, nitrogen, or steam is characterized by low efficiency and high gas consumption (30-50 m³ / day). 3 gas / m 3 Wastewater treatment processes are characterized by low desulfurization efficiency (30-50%), long processing flows, high energy consumption (whether using fuel gas, nitrogen, or steam), and high production and operating costs. Furthermore, these processes are prone to scaling and clogging. For sulfur-containing gas field water treatment, especially large-scale gas field water with high sulfur content, none of the above processes are economical or effective.
[0004] The main problems with current water treatment in sulfur-containing gas fields are high treatment costs and difficulty in achieving H2S standards in the treated water. Summary of the Invention
[0005] The purpose of this application is to overcome the problems of the prior art and disclose a low-energy-consumption and low-pollution emission sulfur-containing gas field water treatment coupling system. This application uses air or other inert gas stripping stripping methods to strip H2S from the gas field water, and then uses the stripped gas for resource utilization, which greatly reduces pollutant emissions and lowers the treatment cost of gas field water desulfurization.
[0006] The objective of this application is achieved through the following technical solution:
[0007] A low-energy-consumption, low-pollution-emission sulfur-containing gas field water treatment coupling system, the sulfur-containing gas field water treatment coupling system comprising:
[0008] Static mixer, pH adjustment tank, stripping blower, gas field water stripping tower and hydrogen sulfide treatment unit;
[0009] The static mixer is connected to the pH adjustment tank, and the pH adjustment tank is connected to the gas field water stripping tower via the stripping tower inlet pump;
[0010] The gas field water stripping tower is also connected to a stripping blower upstream, and the gas field water stripping tower is connected to a downstream hydrogen sulfide treatment unit.
[0011] Produced water from upstream sulfur-containing oil and gas fields enters a static mixer, is premixed with hydrochloric acid, and then enters a pH adjustment tank for stirring. Once the mixture is homogeneous, the pH value is adjusted.
[0012] After the pH value is adjusted, the produced water from the oil and gas field is pumped to the upper part of the gas field water stripping tower via the stripping tower inlet pump. The stripping blower pressurizes the air and sends it to the gas field water stripping tower. The sulfur-containing gas field water and air come into countercurrent contact on the packing material inside the tower. The hydrogen sulfide in the sulfur-containing gas field water is stripped and replaced by the air. The desulfurized gas field water is then sent to the boundary area.
[0013] The hydrogen sulfide-containing air discharged from the top of the gas field water stripping tower enters the downstream hydrogen sulfide treatment unit for resource recovery and produces corresponding products.
[0014] According to a preferred embodiment, the pH adjustment tank adjusts the pH of the sulfur-containing gas field water to 3-5, so that the sulfur ions in the water exist in molecular form.
[0015] According to a preferred embodiment, the blower pressurizes the air to 20 kPa and sends it to the gas field water stripping tower, and the gas field water stripping tower is equipped with a 3-6 m packing layer.
[0016] According to a preferred embodiment, the hydrogen sulfide treatment unit includes: a primary absorption tower and a secondary absorption tower.
[0017] The air containing hydrogen sulfide, fed from the gas field's water stripping tower, first enters the lower part of the primary absorption tower, where it reacts with the lean absorption solution on the tower's trays, initially removing the hydrogen sulfide and converting it into solid sulfur particles.
[0018] The gas phase then enters the secondary absorption tower, where it reacts with the lean absorption solution on the packing material to remove hydrogen sulfide again. The gas after hydrogen sulfide removal meets the emission standards.
[0019] According to a preferred embodiment, the hydrogen sulfide treatment unit further includes: an oxidation regeneration tower, a sulfur filter, and a sulfur refining device;
[0020] The rich solution containing hydrogen sulfide oxidized in the primary and secondary absorption towers, along with the solid sulfur particles generated in the reaction, are pressurized by a solution circulation pump and then enter the oxidation regeneration tower. Inside the oxidation regeneration tower, external air is used to oxidize the solution into a lean solution. The solid sulfur particles settle to the bottom of the oxidation regeneration tower, and the slurry containing sulfur particles is pumped from the bottom of the regeneration tower to a sulfur filter. The filter forms a liquid sulfur paste, and the filtered filtrate is returned to the oxidation regeneration tower.
[0021] According to a preferred embodiment, when the sulfur filter is overloaded, the liquid phase at the bottom of the oxidation regeneration tower is pumped to the top of the oxidation regeneration tower via a bottom pump for internal circulation.
[0022] According to a preferred embodiment, the hydrogen sulfide treatment unit further includes: a sulfur refining device; the sulfur refining device receives liquid sulfur paste from a sulfur filter, liquefies the sulfur paste with steam, separates impurity ions, and obtains sulfur.
[0023] According to a preferred embodiment, the hydrogen sulfide treatment unit includes: a waste gas incinerator and a gypsum production device. The hydrogen sulfide-containing gas from the top of the gas field water stripping tower enters the waste gas incinerator, where the sulfur-containing gas is incinerated to 600-760°C, converting the hydrogen sulfide into sulfur dioxide. The gas then enters the gypsum production device, where calcium oxide or calcium hydroxide is added to absorb and convert the sulfur dioxide into calcium sulfate, thus producing gypsum products.
[0024] According to a preferred embodiment, in the gypsum production equipment, the gas from which sulfur dioxide has been removed is discharged through a chimney.
[0025] According to a preferred embodiment, the hydrogen sulfide treatment unit includes a waste heat boiler, wherein the gas after being burned in the waste gas incinerator enters the waste heat boiler for heat recovery, and the gas temperature is reduced to 220-300°C before being transported to the gypsum production equipment.
[0026] This system utilizes air or other inert gas stripping methods to remove H2S from gas field water. The stripped gas is then converted into sulfur or gypsum for resource utilization, significantly reducing pollutant emissions and lowering the cost of gas field water desulfurization. This system combines gas field water stripping technology with H2S treatment technology, greatly reducing SO2 (<100ppm) or H2S content (<10ppm) in exhaust gas, ensuring that exhaust emissions meet environmental standards such as the "Emission Standard of Air Pollutants for Onshore Oil and Gas Extraction Industry" (GB39728-2020) or the "Emission Standard of Odor Pollutants" (GB14554-1993). The process is simple, with low investment and low operating costs, and produces no solid waste, greatly protecting the environment.
[0027] The aforementioned main solution and its various further alternative solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application. Those skilled in the art, after understanding the solution of this application, will realize that there are many combinations based on the prior art and common general knowledge, all of which are technical solutions to be protected in this application, and will not be exhaustively listed here.
[0028] The beneficial effects of this application are:
[0029] This system should be used when the H2S content in gas field water is less than 3000 ppm and meets the following criteria:
[0030] 1) Adjust the pH value of the gas field water to 3-5 using hydrochloric acid for automatic adjustment and online pH control to achieve precise adjustment;
[0031] 2) The treated gas field water can achieve an H2S content of ≤10ppm, which meets the gas field water reinjection standards or other production needs;
[0032] 3) Air or other inert air stripping is used, and air is widely available and readily accessible, which greatly reduces production and operating costs;
[0033] 4) Using air to remove H2S from water at a lower pressure (~20 kPa.g) greatly saves power consumption and avoids leakage that may be caused by negative pressure air lifting.
[0034] 5) This system uses two sections of 3-6m high Pall ring random packing in the stripping tower to increase the gas-liquid contact area, resulting in high desulfurization efficiency and a gas-liquid ratio of only 20 Nm. 3 air / m 3 Water has low energy consumption;
[0035] 6) The gas stripped from this system can be treated using a liquid-phase oxidation-reduction process, which can convert H2S into sulfur, greatly reducing H2S emissions to <10 mg / Nm³. 3This greatly protects the environment; at the same time, it utilizes sulfur paste as a resource, refining it into qualified sulfur that meets national standards, which can be sold, reducing the difficulty of disposing of sulfur as solid waste.
[0036] 7) The gas stripped from this system can also be burned in a tail gas incinerator, then absorbed by limestone, and finally made into gypsum products, turning waste into treasure, while greatly reducing SO2 emissions, with SO2 emission concentration <100mg / Nm3. Attached Figure Description
[0037] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this application;
[0038] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of this application;
[0039] Among them, 1-static mixer, 2-pH adjustment tank, 3-stripping tower inlet pump, 4-stripping blower, 5-gas field water stripping tower, 6-primary absorption tower, 7-secondary absorption tower, 8-solution circulation pump, 9-oxidation regeneration tower, 10-regeneration tower bottom pump, 11-sulfur filter, 12-sulfur refining equipment, 13-waste gas incinerator, 14-waste heat boiler, 15-gypsum production equipment, 16-chimney. Detailed Implementation
[0040] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.
[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0042] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0043] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0044] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0045] Furthermore, it should be noted that unless otherwise specified in this application, the specific structures, connections, positions, power sources, etc. involved are all things that a person skilled in the art can know without creative effort based on the prior art.
[0046] Example 1:
[0047] refer to Figure 1 As shown, this embodiment discloses a low-energy-consumption, low-pollution-emission coupled system for treating sulfur-containing gas field water. Produced water from an upstream sulfur-containing oil and gas field enters a static mixer 1 and is pre-mixed with 30% hydrochloric acid. An online pH analyzer controls the amount of hydrochloric acid added. The water then enters a pH adjustment tank 2 for stirring and uniform mixing, adjusting the pH to 3-5 to reduce the sulfur content in the water. 2- It exists in molecular form, which facilitates stripping and separation.
[0048] After the pH is adjusted in pH tank 2, the produced water from the oil and gas field is pressurized to 0.3 MPa by the inlet pump 3 of the stripping tower and then sent to the top of the gas field water stripping tower 5. The stripping blower 4 pressurizes the air to ~20 kPa and then enters the gas field water stripping tower 5. The tower is filled with 6m of packing material. The sulfur-containing gas field water and air come into countercurrent contact. The H2S in the sulfur-containing gas field water is stripped and replaced by the air. After the desulfurization, the H2S in the gas field water is <10 ppm and then it is sent to the boundary area.
[0049] The air containing hydrogen sulfide from the top of the gas field water stripping tower 5 enters the lower part of the primary absorption tower 6. The lean solution enters the primary absorption tower 6 from the top and reacts with the lean solution on the trays (with 3 trays) to remove hydrogen sulfide. The hydrogen sulfide is converted into solid sulfur particles. The gas phase after coarse hydrogen sulfide removal enters the lower part of the secondary absorption tower 7 and reacts with the lean solution on the packing material in the secondary absorption tower 7 to further remove hydrogen sulfide. The gas after hydrogen sulfide removal meets the emission standards, and the H2S content in the gas is less than 10 ppm.
[0050] The rich solution containing hydrogen sulfide oxidized in the primary absorption tower 6 and the secondary absorption tower 7, along with the solid sulfur particles generated by the reaction, are pressurized to 0.6 MPa.g by the solution circulation pump 8 and then enter the oxidation regeneration tower 9. In the oxidation regeneration tower 9, the solution is oxidized to a lean solution using external air (~70 kPa.g). The solid sulfur particles settle to the bottom of the oxidation regeneration tower 9. The slurry containing sulfur particles is sent to the sulfur filter 11 by the bottom pump 10 of the regeneration tower. The filter forms a sulfur paste containing ~30% liquid. The filtrate is returned to the oxidation regeneration tower 9. When the filter does not allow the liquid to be filtered, the liquid phase at the bottom of the oxidation regeneration tower 9 is circulated by the bottom pump 10 of the regeneration tower.
[0051] The sulfur refining equipment 12 uses steam to liquefy sulfur paste containing 30% liquid from the sulfur filter 11, separates impurity ions, and obtains qualified sulfur products, which are then sold.
[0052] Example 2
[0053] refer to Figure 2 As shown, this embodiment discloses a low-energy-consumption, low-pollution-emission coupled system for treating sulfur-containing gas field water. Produced water from an upstream sulfur-containing oil and gas field enters a static mixer 1 and is pre-mixed with 30% hydrochloric acid. An online pH analyzer controls the amount of hydrochloric acid added. The water then enters a pH adjustment tank 2 for stirring and uniform mixing, adjusting the pH to 3-5 to reduce the sulfur content in the water. 2- It exists in molecular form, which facilitates stripping and separation.
[0054] After the pH is adjusted in pH tank 2, the produced water from the oil and gas field is pressurized to 0.3 MPa by the inlet pump 3 of the stripping tower and then sent to the top of the gas field water stripping tower 5. The stripping blower 4 pressurizes the air to ~20 kPa and then enters the gas field water stripping tower 5. The tower is filled with 3m of packing material. The sulfur-containing gas field water and air come into countercurrent contact. The H2S in the sulfur-containing gas field water is stripped and replaced by the air. After the desulfurization, the H2S in the gas field water is <10 ppm and then it is sent to the boundary area.
[0055] Hydrogen sulfide-containing gas from the top of the water stripping tower 5 in the gas field first enters the waste gas combustion furnace 13. Under the high temperature of fuel gas and air combustion, the sulfur-containing gas is burned to 600-760℃, almost completely converting H2S into SO2. The burned gas then enters the waste heat boiler 14 for heat recovery, reducing the waste gas temperature to 220-300℃. It then enters the gypsum production equipment 15, where calcium oxide or calcium hydroxide is added to absorb SO2 and convert it into calcium sulfate, producing gypsum products for sale. The gas, after SO2 removal, is discharged through the chimney 16, meeting emission standards, with an SO2 emission concentration of less than 100 mg / Nm³. 3 .
[0056] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A low-energy-consumption, low-pollution-emission coupled system for treating sulfur-containing gas field water, characterized in that, The sulfur-containing gas field water treatment coupling system includes: Static mixer (1), pH adjustment tank (2), stripping blower (4), gas field water stripping tower (5) and hydrogen sulfide treatment unit; The static mixer (1) is connected to the pH adjustment tank (2), and the pH adjustment tank (2) is connected to the gas field water stripping tower (5) via the stripping tower inlet pump (3); The gas field water stripping tower (5) is also connected to a stripping blower (4) upstream, and the gas field water stripping tower (5) is connected to a downstream hydrogen sulfide treatment unit. Produced water from upstream sulfur-containing oil and gas fields enters a static mixer (1) and is premixed with hydrochloric acid. Then it enters a pH adjustment tank (2) for stirring to complete pH adjustment. After adjusting the pH value, the produced water from the oil and gas field is sent to the upper part of the gas field water stripping tower (5) via the stripping tower inlet pump (3). The stripping blower (4) pressurizes the air and sends it to the gas field water stripping tower (5). The sulfur-containing gas field water and air come into countercurrent contact on the packing material inside the tower. The hydrogen sulfide in the sulfur-containing gas field water is stripped and replaced by the air. The desulfurized gas field water is sent to the boundary area. The air containing hydrogen sulfide discharged from the top of the gas field water stripping tower (5) enters the downstream hydrogen sulfide treatment unit for resource recovery and produces corresponding products.
2. The sulfur-containing gas field water treatment coupling system as described in claim 1, characterized in that, The pH adjustment tank (2) adjusts the pH of the sulfur-containing gas field water to 3-5, so that the sulfur ions in the water exist in the molecular form.
3. The sulfur-containing gas field water treatment coupling system as described in claim 1, characterized in that, The blower (4) pressurizes the air to 20 kPa and sends it to the gas field water stripping tower (5), and the gas field water stripping tower (5) is equipped with a 3-6 m packing layer.
4. The sulfur-containing gas field water treatment coupling system as described in claim 1, characterized in that, The hydrogen sulfide treatment unit includes: a primary absorption tower (6) and a secondary absorption tower (7). The air containing hydrogen sulfide, fed from the gas field water stripping tower (5), first enters the lower middle part of the primary absorption tower (6), where it reacts with the lean absorption solution on the tower trays to initially remove the hydrogen sulfide. The hydrogen sulfide is then converted into solid sulfur particles. The gas phase then enters the secondary absorption tower (7), where it reacts with the lean absorption solution on the packing material to remove hydrogen sulfide again. The gas after removing hydrogen sulfide is discharged in compliance with standards.
5. The sulfur-containing gas field water treatment coupling system as described in claim 4, characterized in that, The hydrogen sulfide treatment unit also includes: an oxidation regeneration tower (9), a sulfur filter (11), and a sulfur refining device (12); The hydrogen sulfide-rich solution and the solid sulfur particles generated by the reaction after being oxidized in the primary absorption tower (6) and the secondary absorption tower (7) are pressurized by the solution circulation pump (8) and then enter the oxidation regeneration tower (9). In the oxidation regeneration tower (9), the solution is oxidized into a lean solution by external air. The solid sulfur particles settle to the bottom of the oxidation regeneration tower (9). The slurry containing sulfur particles is sent to the sulfur filter (11) by the bottom pump (10) of the regeneration tower. The filtration forms a liquid sulfur paste. The filtrate after filtration is returned to the oxidation regeneration tower (9).
6. The sulfur-containing gas field water treatment coupling system as described in claim 5, characterized in that, When the sulfur filter (11) is overloaded, the liquid phase at the bottom of the oxidation regeneration tower (9) is transported to the top of the oxidation regeneration tower (9) via the bottom pump (10) for internal circulation.
7. The sulfur-containing gas field water treatment coupling system as described in claim 5, characterized in that, The hydrogen sulfide treatment unit also includes: sulfur refining equipment (12); The sulfur refining equipment (12) receives liquid sulfur paste from the sulfur filter (11), liquefies the sulfur paste with steam, separates impurity ions, and obtains sulfur.
8. The sulfur-containing gas field water treatment coupling system as described in claim 1, characterized in that, The hydrogen sulfide treatment unit includes: a waste gas incinerator (13) and a gypsum production device (15). The hydrogen sulfide-containing gas from the top of the gas field water stripping tower (5) enters the waste gas incinerator (13), where the sulfur-containing gas is incinerated to 600-760°C, converting the hydrogen sulfide into sulfur dioxide. The gas then enters the gypsum production equipment (15), where calcium oxide or calcium hydroxide is added to absorb and convert the sulfur dioxide into calcium sulfate, thus producing gypsum products.
9. The sulfur-containing gas field water treatment coupling system as described in claim 8, characterized in that, In the gypsum production equipment (15), the gas from which sulfur dioxide has been removed is discharged through the chimney (16).
10. The sulfur-containing gas field water treatment coupling system as described in claim 8, characterized in that, The hydrogen sulfide treatment unit includes: a waste heat boiler (14), The gas burned by the waste gas incinerator (13) enters the waste heat boiler (14) for heat recovery. After the gas temperature is reduced to 220-300℃, it is transported to the gypsum production equipment (15).