Device for removing hydrogen sulfide from oilfield produced water

Abstract

The utility model discloses a device for removing hydrogen sulfide from oilfield produced water, which can reliably remove hydrogen sulfide gas dissolved in the water, is low in operation energy consumption and reduces the cost. The device comprises a water inlet pipeline; a nitrogen purging pipeline; an exhaust gas emission main pipeline; treated water flows out of the pipeline; each group of hydrogen sulfide removal membrane contactors comprises a contactor body, a water inlet, a water outlet, a purge gas inlet and a waste gas outlet, and the water inlets and the water outlets of all the hydrogen sulfide removal membrane contactors are sequentially connected in series to form a total water inlet and a total water outlet corresponding to the water inlet pipeline; a lifting pump is integrated at an inlet of the water inlet pipeline, and a water inlet flow meter and a plurality of security filters are arranged on the water inlet pipeline in the water flowing direction.

Description

Technical Field

[0001] This utility model relates to the technical field of oilfield produced water treatment, specifically to a device for removing hydrogen sulfide from oilfield produced water. Background Technology

[0002] The produced water from existing oil fields contains dissolved hydrogen sulfide, which needs to be removed before the produced water can be used. Currently, the produced water is produced by removing the dissolved hydrogen sulfide from the water through a degassing tower. The degassing tower consumes a lot of energy to remove the dissolved hydrogen sulfide from the water, and the gas-to-water ratio of the degassing tower is usually greater than 35:1, which leads to high cost for hydrogen sulfide removal. Utility Model Content

[0003] To address the aforementioned problems, this invention provides a device for removing hydrogen sulfide from produced water in oil fields. This device reliably removes dissolved hydrogen sulfide gas from the produced water and has low operating energy consumption, thus reducing costs.

[0004] An apparatus for removing hydrogen sulfide from produced water from an oilfield, characterized in that it comprises:

[0005] Water inlet pipe;

[0006] Nitrogen purging lines;

[0007] Main exhaust pipe;

[0008] The treated water flows out of the pipe;

[0009] And at least one set of desulfurization membrane contactors, each set of desulfurization membrane contactors includes a contactor body, a water inlet, a water outlet, a purge gas inlet, and an exhaust gas outlet. The water inlets and water outlets of all the desulfurization membrane contactors are connected in series to form a total water inlet and a total water outlet corresponding to the water inlet pipe.

[0010] The inlet of the water inlet pipe is equipped with a booster pump, and the water inlet pipe is equipped with an inlet flow meter and several security filters along the water flow direction.

[0011] An external water inlet pipe is connected to the inlet of the booster pump. The outlet of the water inlet pipe is connected to the water inlet of the first hydrogen sulfide removal membrane contactor, i.e., the total water inlet. The water outlet of the last hydrogen sulfide removal membrane contactor, i.e., the total water outlet, is connected to the inlet of the treated water outflow pipe. Nitrogen purging pipes are connected in parallel to each of the purging gas inlets. Each of the exhaust gas outlets is connected in parallel to the inlet of the exhaust gas discharge main pipe. The outlet of the exhaust gas discharge main pipe is connected to an external exhaust gas treatment device.

[0012] Its further features are:

[0013] The number of hydrogen sulfide desulfurization membrane contactors is three sets, which are arranged vertically in parallel. The water inlet of each hydrogen sulfide desulfurization membrane contactor is located at the bottom, and the water outlet is located at the top. The three sets of hydrogen sulfide desulfurization membrane contactors are the first hydrogen sulfide desulfurization membrane contactor, the second hydrogen sulfide desulfurization membrane contactor, and the third hydrogen sulfide desulfurization membrane contactor. The top water outlet of the first hydrogen sulfide desulfurization membrane contactor is connected to the bottom water inlet of the second hydrogen sulfide desulfurization membrane contactor through a first bent connecting pipe. The top water outlet of the second hydrogen sulfide desulfurization membrane contactor is connected to the bottom water inlet of the third hydrogen sulfide desulfurization membrane contactor through a second bent connecting pipe, forming a series mechanism.

[0014] The nitrogen purging pipeline is equipped with a nitrogen inlet pressure gauge and a nitrogen inlet flow meter. The pressure of the nitrogen inlet pressure gauge is controlled to be less than 0.1 MPa by adjusting the valve, and the flow rate of the nitrogen inlet is controlled by the nitrogen inlet flow meter to ensure that the gas-water ratio is greater than 3:1.

[0015] The inlet pipe is connected to an inlet hydrogen sulfide content detector, and the treated water outlet pipe is also connected to an outlet hydrogen sulfide content detector. The inlet hydrogen sulfide content detector detects the hydrogen sulfide content of the inlet water, and the outlet hydrogen sulfide content detector detects the hydrogen sulfide content of the treated water. These two instruments are used to monitor the performance of the desulfurization membrane contactor.

[0016] The water inlet pipe includes a first lifting section, a first horizontal section, a second descending section, and a second horizontal section. A lifting pump is installed at the bottom inlet of the first lifting section, and a water inlet flow meter is integrated on the first lifting section. Several security filters are installed on the second descending section, and the outlet of the second horizontal section is connected to the water inlet of the first hydrogen sulfide desulfurization membrane contactor through a vertical connecting pipe.

[0017] It also includes a control cabinet containing electrical equipment and automatic control programs to ensure that the entire device can operate fully automatically.

[0018] The working principle of the desulfurization membrane contactor after adopting this utility model is as follows: Figure 2The gas transfer membrane material used is a selectively permeable material. The hydrogen sulfide removal membrane contactor contains a large number of hollow fibers with tiny pores on the fiber walls. Only gas molecules can pass through these micropores, allowing gas to permeate bidirectionally while liquids cannot. Gas-liquid contact is established on both sides of the material. Gas flow carries gas from the liquid into the liquid, thus reducing the gas content in the liquid. During operation, the hydrogen sulfide-containing wastewater is pressurized to 0.3 MPa by a booster pump and then filtered through a security filter. Impurities in the wastewater are removed, reducing the turbidity to less than 0.1 NTU. The wastewater then enters a hydrogen sulfide removal membrane contactor, where nitrogen gas is introduced into the nitrogen purging pipeline. By controlling the flow rate of the purging nitrogen, the gas-to-water ratio must be greater than 3:1. The hydrogen sulfide removal membrane contactor removes dissolved hydrogen sulfide gas from the oilfield produced water. The water is then discharged from the outlet of the main exhaust gas pipeline and enters the downstream exhaust gas treatment unit for further treatment. The water with hydrogen sulfide removed flows out from the treated wastewater outlet pipeline. The dissolved hydrogen sulfide gas content in the removed water is essentially zero, resulting in low operating energy consumption and reduced costs. Attached Figure Description

[0019] Figure 1 This is a schematic block diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the desulfurization membrane contactor used in this utility model;

[0021] The names corresponding to the serial numbers in the diagram are as follows:

[0022] 1. Contactor body; 2. Water inlet; 3. Water outlet; 4. Purge gas inlet; 5. Exhaust gas outlet; 6. First bend connecting pipe; 7. Second bend connecting pipe.

[0023] Water inlet pipe 10, lift pump 11, inlet flow meter 12, security filter 13, first lifting section 101, first horizontal section 102, second descending section 103, second horizontal section 104, vertical connecting pipe 105, nitrogen purging pipeline 20, nitrogen inlet pressure gauge 21, nitrogen inlet flow meter 22, exhaust gas discharge main pipeline 30, treated water outflow pipeline 40, first desulfurization membrane contactor 50, second desulfurization membrane contactor 60, third desulfurization membrane contactor 70, control cabinet 80, inlet water hydrogen sulfide content detection instrument 90, effluent water hydrogen sulfide content detection instrument 100. Detailed Implementation

[0024] An apparatus for removing hydrogen sulfide from produced water in oil fields, see Figure 1 and Figure 2 It includes

[0025] Water inlet pipe 10, nitrogen purging pipe 20, exhaust gas main pipe 30, treated water outflow pipe 40, and three sets of desulfurization membrane contactors;

[0026] Each set of hydrogen sulfide desulfurization membrane contactors includes a contactor body 1, a water inlet 2, a water outlet 3, a purge gas inlet 4, and an exhaust gas outlet 5. The three sets of hydrogen sulfide desulfurization membrane contactors are arranged vertically in parallel, with the water inlet of the hydrogen sulfide desulfurization membrane contactor located at the bottom and the water outlet located at the top. The three sets of hydrogen sulfide desulfurization membrane contactors are the first hydrogen sulfide desulfurization membrane contactor 50, the second hydrogen sulfide desulfurization membrane contactor 60, and the third hydrogen sulfide desulfurization membrane contactor 70. The water outlet 3 at the top of the first hydrogen sulfide desulfurization membrane contactor 50 is connected to the water inlet 2 at the bottom of the second hydrogen sulfide desulfurization membrane contactor 60 through the first bent connecting pipe 6. The water outlet 3 at the top of the second hydrogen sulfide desulfurization membrane contactor 60 is connected to the water inlet 2 at the bottom of the third hydrogen sulfide desulfurization membrane contactor 70 through the second bent connecting pipe 7, forming a series mechanism.

[0027] The inlet of the water inlet pipe 10 is integrated with a booster pump 11, and the water inlet pipe 10 is equipped with an inlet flow meter 12 and several security filters 13 along the water flow direction.

[0028] The external water inlet pipe is connected to the inlet of the booster pump 11. The outlet of the water inlet pipe 10 is connected to the water inlet 2 of the first desulfurization membrane contactor 50, i.e., the total water inlet. The water outlet 3 of the third desulfurization membrane contactor 70, i.e., the total water outlet, is connected to the inlet of the treated water outflow pipe 40. The nitrogen purging pipe 20 is connected in parallel to each purging gas inlet 4. Each exhaust gas outlet 5 is connected in parallel to the inlet of the exhaust gas discharge main pipe 30. The outlet of the exhaust gas discharge main pipe 30 is connected to the exhaust gas treatment device.

[0029] In practice: the nitrogen purging pipeline 20 is equipped with a nitrogen inlet pressure gauge 21 and a nitrogen inlet flow meter 22. The pressure of the nitrogen inlet pressure gauge 21 is controlled to be less than 0.1 MPa by adjusting the valve, and the flow rate of the nitrogen inlet is controlled by the nitrogen inlet flow meter 22 to make the gas-water ratio greater than 3:1.

[0030] The inlet pipe 10 is connected to an inlet hydrogen sulfide content detector 90, and the treated water outlet pipe 40 is also connected to an outlet hydrogen sulfide content detector 100. The inlet hydrogen sulfide content detector 90 detects the hydrogen sulfide content of the inlet water, and the outlet hydrogen sulfide content detector 100 detects the hydrogen sulfide content of the treated water. These two instruments are used to monitor the performance of the desulfurization membrane contactor.

[0031] The water inlet pipe 10 includes a first lifting section 101, a first horizontal section 102, a second descending section 103, and a second horizontal section 104. A lifting pump 11 is installed at the bottom inlet of the first lifting section 101. A water inlet flow meter 12 is integrated on the first lifting section 101. Several security filters 13 are installed on the second descending section 103. The outlet of the second horizontal section 104 is connected to the water inlet of the first hydrogen sulfide desulfurization membrane contactor 50 through a vertical connecting pipe 105.

[0032] It also includes a control cabinet 80, which contains electrical equipment and automatic control programs to ensure that the entire device can operate fully automatically.

[0033] During operation, the hydrogen sulfide-containing wastewater is pressurized to 0.3 MPa by a booster pump, then filtered through a security filter to remove impurities, reducing the turbidity to less than 0.1 NTU. The wastewater then enters three sets of desulfurization membrane contactors connected in series. Nitrogen gas enters the nitrogen purging pipeline, and the gas-to-water ratio is controlled to be greater than 3:1. The desulfurization membrane contactors remove dissolved hydrogen sulfide gas from the oilfield produced water, which is then discharged from the outlet of the main exhaust pipeline and enters the downstream exhaust gas treatment unit for further processing. The desulfurized water flows out from the treated wastewater outlet pipeline. Because of the three sets of desulfurization membrane contactors connected in series, the dissolved hydrogen sulfide gas content in the removed water is essentially zero, and the operating energy consumption is low, reducing costs.

[0034] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0035] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An apparatus for removing hydrogen sulfide from oilfield produced water, the apparatus comprising: It comprises: a water inlet pipe; a nitrogen purge pipe; an exhaust gas discharge main pipe; a treated water outlet pipe; and at least one group of hydrogen sulfide removal membrane contactors, each group of hydrogen sulfide removal membrane contactors comprising a contactor body, a water inlet, a water outlet, a purge gas inlet, an exhaust gas outlet, the water inlets and water outlets of all hydrogen sulfide removal membrane contactors being sequentially connected in series to form a total water inlet and a total water outlet corresponding to the water inlet pipe; the inlet of the water inlet pipe is integrated with a booster pump, and the water inlet pipe is provided with a water inlet flow meter and a plurality of safety filters along the water flow direction; an external water inlet pipe is connected to the inlet of the booster pump, the outlet of the water inlet pipe is connected to the water inlet, i.e. the total water inlet, of the first hydrogen sulfide removal membrane contactor, and the water outlet, i.e. the total water outlet, of the last hydrogen sulfide removal membrane contactor is externally connected to the inlet of the treated water outlet pipe, the nitrogen purge pipes are respectively connected in parallel to each purge gas inlet, and each exhaust gas outlet is respectively connected in parallel to the inlet of the exhaust gas discharge main pipe, and the outlet of the exhaust gas discharge main pipe is externally connected to an exhaust gas treatment device.

2. The apparatus for removing hydrogen sulfide from oilfield produced water of claim 1, wherein: The number of hydrogen sulfide removal membrane contactors is three groups, and the three groups of hydrogen sulfide removal membrane contactors are arranged vertically and in parallel, with the water inlets located below and the water outlets located above, and the three groups of hydrogen sulfide removal membrane contactors are respectively a first hydrogen sulfide removal membrane contactor, a second hydrogen sulfide removal membrane contactor, and a third hydrogen sulfide removal membrane contactor, the top water outlet of the first hydrogen sulfide removal membrane contactor is connected to the bottom water inlet of the second hydrogen sulfide removal membrane contactor through a first bending connection pipe, and the top water outlet of the second hydrogen sulfide removal membrane contactor is connected to the bottom water inlet of the third hydrogen sulfide removal membrane contactor through a second bending connection pipe, forming a series mechanism.

3. The apparatus for removing hydrogen sulfide from oilfield produced water of claim 1, wherein: A nitrogen inlet pressure gauge and a nitrogen inlet flow meter are integrated on the nitrogen purge pipe.

4. The apparatus for removing hydrogen sulfide from oilfield produced water of claim 1, wherein: A water inlet hydrogen sulfide content detection instrument is connected to the starting end of the water inlet pipe, and a treated water outlet pipe is also externally connected to a water outlet hydrogen sulfide content detection instrument.

5. The apparatus for removing hydrogen sulfide from oilfield produced water of claim 2, wherein: The water inlet pipe comprises a first lifting section, a first horizontal section, a second descending section, and a second horizontal section, the bottom inlet of the first lifting section is provided with a booster pump, the first lifting section is integrated with a water inlet flow meter, the second descending section is provided with a plurality of safety filters, and the outlet of the second horizontal section is connected to the water inlet of the first hydrogen sulfide removal membrane contactor through a vertical connection pipe.

6. The apparatus for removing hydrogen sulfide from oilfield produced water of claim 1, wherein: It further comprises a control electrical cabinet containing electrical equipment and automatic control programs.

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