Land optimization debugging method of ethylene glycol regeneration system for inhibiting natural gas hydrate in offshore oil and gas field engineering

Abstract

The invention provides a land optimization debugging method of an ethylene glycol regeneration system for natural gas hydrate inhibition in offshore oil and gas field engineering, which comprises the following steps: ensuring that an MRU is built and a mechanical completion certificate is obtained before testing; shore power or a temporary generator is used for supplying power to the MRU according to design parameters; hot oil stored in a temporary storage tank is connected into a heating device for circulation, and seawater is introduced into a cooling device for external discharge for circulation; recovering the pipeline after equipment installation and single machine debugging are completed; establishing a simulation process by taking water as a medium; calculating the mixing proportion of water, MEG, salt and the like in the rich MEG according to design parameters; according to the calculation result, temporary pipeline mixed materials are connected, and the flow is controlled by a delivery pump; alkali liquor and an organic solvent are respectively arranged at an acid gas discharge port and a light hydrocarbon discharge port for absorption; filling rich MEG, performing MRU thermal-state operation according to a standard first through the process, and verifying the separation effect of each unit after the operation is stable; and verifying the overall processing effect of the MRU. According to the method, problems can be found and solved in time, and it is guaranteed that production can be conducted as soon as possible after offshore installation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of offshore engineering, and particularly relates to a land optimization commissioning method for a mono-ethylene glycol recovery unit for hydrate inhibition of offshore oil and gas field engineering. BACKGROUND

[0002] An important problem of offshore natural gas production is that hydrate is easily formed when natural gas flows in long-distance low-temperature high-pressure pipelines, thereby causing ice blockage. Therefore, hydrate inhibition is extremely important for offshore natural gas production. At present, the most widely used hydrate inhibitor in offshore oil and gas development is mono-ethylene glycol (MEG). Correspondingly, a mono-ethylene glycol recovery unit (MRU) removes water, salt, hydrocarbons and acid gases in MEG rich liquid to obtain MEG lean liquid meeting the injection purity requirement, so as to realize recycling use of MEG. A typical process flow of MRU can refer to Figure 2 .

[0003] The MRU system is complex, and the related devices in the integrated system are numerous. In order to shorten the overall construction period of offshore engineering facilities, the MRU is generally designed as an integrated module, which is transported to the sea separately, connected with other main parts of offshore natural gas production facilities, and then overall commissioning is performed.

[0004] The MRU is an important part of offshore natural gas development. After installation on the sea, the MRU needs to be put into production as soon as possible to avoid affecting the production progress. In addition, if the MRU is commissioned on the sea, the commissioning conditions are limited, and there is a lack of sufficient manpower and material resources, so the commissioning efficiency is low. Therefore, it is important to start up and simulate test the MRU on land to the greatest extent, and there is no related simulation test technology published at present. SUMMARY

[0005] In order to solve the technical problem that there is no method for starting up and simulating test the MRU on land in the prior art, and the MRU cannot be put into production as soon as possible after installation on the sea, the present application provides a land optimization commissioning method for a mono-ethylene glycol recovery unit for hydrate inhibition of offshore oil and gas field engineering.

[0006] The land optimization commissioning method for a mono-ethylene glycol recovery unit for hydrate inhibition of offshore oil and gas field engineering provided by the present application adopts the following technical scheme: A land optimization commissioning method for a mono-ethylene glycol recovery unit for hydrate inhibition of offshore oil and gas field engineering, comprising the following steps: S1: ensuring that the MRU has been completed and the corresponding mechanical completion certificate has been obtained before formal test; S2: Power the MRU with shore power or temporary generator according to the specific design parameters of the MRU; S3: Set up a temporary storage tank to store hot oil and connect the flow to the corresponding MRU heating device and circulate, and connect the flow of seawater from the terminal to the corresponding MRU cooling device and circulate; S4: Ensure that all equipment has been installed on the MRU, and that all MRU equipment is debugged according to relevant specifications, and the corresponding pipelines are restored after single machine debugging; S5: Simulate the process with water as the medium to check the integrity and continuity of the MRU system process, and establish the same pressure and flow as in actual operation by adjusting pumps, valves, etc., while putting into as many pipelines, equipment and instruments as possible to simulate normal production conditions; S6: According to the design parameters of the MRU, calculate the mixing ratio of water, MEG, salt, hydrocarbon and acid gas in the rich MEG under actual working conditions; S7: According to the calculation results of S6, set up temporary pipelines at the rich MEG input end of the MRU system and the poor MEG output end of the MRU system, connect the pipelines in the order of "MRU poor MEG outlet-automatic dosing and stirring device-conveying pump-MRU rich MEG inlet" to mix water, salt, hydrocarbon, acid gas and poor MEG, and use the conveying pump to control the flow to meet the actual working conditions; S8: Set up alkali solution at the acid gas discharge port of the MRU for absorbing separated acid gas, and set up organic solvent at the light hydrocarbon gas discharge port of the MRU for absorbing separated light hydrocarbon; S9: Fill the rich MEG into the entire flow of the MRU, and start each device of the MRU in turn according to the operation specification of the MRU, which should be first guided through the flow, and then run in hot state; S10: After the MRU runs stably, collect the produced production water, salt and hydrocarbon respectively and calculate their MEG content to verify the separation effect of each unit, and if problems are found, they should be rectified in time; S11: Further verify the overall treatment effect of the MRU, specifically, collect the poor MEG at the outlet and test its salt content, hydrocarbon content and acid content, and further calculate the overall recovery rate of MEG according to the flow of the poor MEG at the outlet and the flow of the rich MEG at the inlet.

[0007] Further, in order to ensure that there is no problem when putting into production, the production simulation test time should be 45-60 days.

[0008] Further, in step S5, the simulation process test time should be at least 2 days.

[0009] Further, between steps S5 and S6, the control instruments and shutdown system should also be debugged at the same time during the simulation process test.

[0010] Furthermore, if problems arise between steps S7 and S8 where hydrocarbons and acidic gases are difficult to dissolve, the hydrocarbons can be pre-mixed with lean MEG, and the acidic gases can be pre-mixed with water.

[0011] Furthermore, between steps S7 and S8, a lean MEG sampling port should be set up near the MRU lean MEG outlet to check the overall treatment effect of the MRU, a sampling port should be set up after the automatic dosing and stirring device to check whether the content of each component of the rich MEG meets the actual working conditions, and a flow meter should be set up after the delivery pump to verify whether its flow rate meets the actual working conditions.

[0012] In summary, the beneficial effects of the present invention are as follows: 1. This method uses water as a medium to simulate and establish test conditions, thereby verifying the integrity and continuity of the process.

[0013] 2. This method converts the poor MEG generated by MRU treatment into rich MEG by establishing a temporary drug injection procedure.

[0014] 3. This method uses a pump at the MRU inlet to simulate the flow rate during actual production. Simulating the actual flow rate can verify the system's processing capacity under the design load and ensure that it can meet production needs after commissioning.

[0015] 4. This method verifies the treatment effect by detecting the content of each component in MEG-poor and MEG-rich environments.

[0016] 5. This method involves rigorous and meticulous testing, from individual equipment testing to process testing and production simulation testing. It ensures that any problems are identified and resolved promptly, guaranteeing that the equipment can be put into production as soon as possible after installation at sea without affecting the production schedule. Attached Figure Description

[0017] Figure 1 This is a flowchart of the debugging method of the present invention; Figure 2 This is a process flow diagram of the ethylene glycol regeneration system of the present invention; Figure 3 This is the temporary power distribution diagram for the MRU of this invention. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0019] Example: Figures 1-3 This paper presents a land-based optimization and commissioning method for an ethylene glycol regeneration system used to suppress natural gas hydrates in offshore oil and gas field engineering.

[0020] Reference Figures 1-3As shown, this invention discloses a land-based optimization and commissioning method for an ethylene glycol regeneration system used to suppress natural gas hydrates in offshore oil and gas field engineering, comprising the following steps: Step 1: Before formal testing, ensure that the MRU has been built and obtained the corresponding mechanical completion certificate to provide a qualified hardware foundation for subsequent commissioning and ensure that the commissioning object meets the basic requirements.

[0021] Step 2: Based on the specific design parameters of the MRU, supply power to the MRU using shore power or a temporary generator. Specific power distribution methods can be found in [reference needed]. Figure 3 ; Step 3: Set up temporary storage tanks to store hot oil and connect them to the corresponding MRU heating device in the process cycle; connect the seawater at the dock to the corresponding MRU cooling device in the process cycle and discharge it outwards in the circulation. Step 4: Ensure that all equipment has been installed on the MRU, perform individual commissioning of all MRU equipment according to relevant specifications, and restore the corresponding pipelines after individual commissioning to ensure that each equipment operates normally on its own.

[0022] Step 5: Establish a simulated process using water as the medium to check the integrity and continuity of the MRU system process. By adjusting pumps, valves, etc., establish the same pressure and flow as in actual operation. At the same time, put in as many pipelines, equipment and instruments as possible to simulate normal production conditions. The simulated process test time should be at least 2 days. By using water as the medium to simulate the test conditions, the integrity and continuity of the process can be verified, and problems in the process can be detected in a timely manner.

[0023] Step 6: During the simulated process test, simultaneously debug the control instruments and the shutdown system; Step 7: Based on the design parameters of the MRU, calculate the mixing ratio of water, MEG, salt, hydrocarbons and acidic gases in the MEG-rich solution under actual operating conditions; Step 8: Based on the calculation results in Step 7, temporary pipelines are set up at the lean MEG output end and the rich MEG input end of the MRU system. The pipelines are connected in the order of "MRU lean MEG outlet - automatic dosing and stirring device - transfer pump - MRU rich MEG inlet" to mix water, salt, hydrocarbons, acidic gases with lean MEG. At the same time, the flow rate is controlled by the transfer pump to conform to the actual working conditions. Step 9: If problems arise with the dissolution of hydrocarbons and acidic gases, the hydrocarbons can be pre-mixed with lean MEG and the acidic gases can be mixed with water to solve the mixing problem, ensure smooth commissioning, and guarantee the accuracy of the simulated operating conditions.

[0024] Step 10: Set up a lean MEG sampling port near the MRU lean MEG outlet to check the overall treatment effect of the MRU. Set up a sampling port after the automatic dosing and stirring device to check whether the content of each component of rich MEG meets the actual working conditions. Set up a flow meter after the delivery pump to verify whether its flow rate meets the actual working conditions. This method verifies the treatment effect by detecting the content of each component of lean MEG and rich MEG. Step 11: Set up an alkaline solution at the acid gas emission port of the MRU to absorb the separated acid gas, and set up an organic solvent at the light hydrocarbon emission port of the MRU to absorb the separated light hydrocarbon, thereby treating the harmful gases generated during the commissioning process, ensuring a safe commissioning environment, and avoiding environmental pollution and safety hazards.

[0025] Step 12: The entire process of filling the MRU with MEG should be carried out by starting each device of the MRU in sequence according to the MRU operating specifications. The process should be started first, and then the MRU should be run in hot state. Step 13: After the MRU is running smoothly, collect the production water, salt and hydrocarbons produced by the separation and calculate their MEG content to verify the separation effect of each unit. If any problems are found, they should be rectified in time. Step 14: Further verify the overall treatment effect of MRU. Specifically, collect lean MEG at the outlet and test its salt content, hydrocarbon content and acid content. Then, calculate the overall MEG recovery rate based on the flow rate of lean MEG at the outlet and the flow rate of rich MEG at the inlet. Step 15: To ensure that no problems occur during production, the production simulation test should last for 45-60 days. Through long-term simulation operation, the stability and reliability of the MRU during operation are fully verified to ensure that no problems occur during production.

[0026] This method verifies the integrity and continuity of the process by simulating test conditions using water as the medium; it converts lean MEG produced by MRU treatment into rich MEG by setting up a temporary reagent injection process; it simulates the actual production flow rate at the MRU inlet using a pump, and the simulated actual flow rate verifies the system's processing capacity under the design load, ensuring that it can meet production needs after commissioning; and it verifies the treatment effect by detecting the content of each component of lean and rich MEG. This method is rigorous and thorough in its testing process, from individual equipment testing to process testing and production simulation testing, ensuring that problems are identified and resolved in a timely manner.

[0027] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. The various components mentioned in the present application are common techniques in the prior art, and those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A land-based method of optimizing commissioning of an ethylene glycol regeneration system for natural gas hydrate inhibition in offshore oil and gas field engineering, characterized in that, The method comprises the following steps: S1: Ensure that the MRU has been built and completed and has obtained the corresponding mechanical completion certificate before formal testing; S2: According to the specific design parameters of the MRU, use shore power or a temporary generator to power the MRU; S3: Set up a temporary storage tank to store hot oil and connect the corresponding MRU heating device process and cycle, and connect the seawater of the wharf to the corresponding MRU cooling device process and cycle; S4: Ensure that all equipment has been installed on the MRU, and perform single machine debugging on all MRU equipment according to relevant specifications, and restore the corresponding pipelines after single machine debugging; S5: Simulate the process with water as the medium to check the integrity and continuity of the MRU system process, and establish the same pressure and flow as in actual operation by adjusting pumps, valves, etc., while putting into as many pipelines, equipment and instruments as possible to simulate normal production conditions; S6: According to the design parameters of the MRU, calculate the mixing ratio of water, MEG, salt, hydrocarbon and acid gas in the rich MEG under actual working conditions; S7: According to the calculation results of S6, set up temporary pipelines at the rich MEG input end of the MRU system and the poor MEG output end of the MRU system, connect the pipelines in the order of "MRU poor MEG outlet-automatic dosing and stirring device-conveying pump-MRU rich MEG inlet" to mix water, salt, hydrocarbon, acid gas and poor MEG, and use the conveying pump to control the flow to meet the actual working conditions; S8: Set up lye at the acid gas discharge port of the MRU for absorbing separated acid gas, and set up organic solvent at the light hydrocarbon gas discharge port of the MRU for absorbing separated light hydrocarbon; S9: Fill the rich MEG into the entire process of the MRU, and start the devices of the MRU in turn according to the operation specification of the MRU, which should be started in the order of process first and then hot state running of the MRU; S10: After the MRU runs stably, collect the produced production water, salt and hydrocarbon respectively and calculate their MEG content to verify the separation effect of each unit, and if problems are found, they should be timely rectified; S11: Further verify the overall treatment effect of the MRU, specifically, collect the poor MEG at the outlet and test its salt content, hydrocarbon content and acid content, and further calculate the overall recovery rate of MEG according to the flow of the poor MEG at the outlet and the flow of the rich MEG at the inlet.

2. The land-based optimization commissioning method of a glycol regeneration system for hydrate inhibition in offshore oil and gas field engineering according to claim 1, characterized in that, In order to ensure that there are no problems during production, the production simulation test time should be 45-60 days.

3. The land-based commissioning method of claim 1, wherein, In step S5, the simulation process test time should be at least 2 days.

4. The land-based commissioning method of claim 1, wherein, Between steps S5 and S6, the control instruments and shutdown system should also be debugged at the same time during the simulation process test.

5. The onshore commissioning method of an ethylene glycol regeneration system for hydrate inhibition in offshore oil and gas field engineering according to claim 1, characterized in that, If the hydrocarbon and acid gas are not easily dissolved between steps S7 and S8, the hydrocarbon and the poor MEG can be mixed in advance respectively, and the acid gas and water can be mixed in advance respectively.

6. The onshore commissioning method of an ethylene glycol regeneration system for hydrate inhibition in offshore oil and gas field engineering according to claim 1, characterized in that, Between steps S7 and S8, a poor MEG sampling port should also be set near the MRU poor MEG outlet for testing the overall treatment effect of the MRU, a sampling port should be set after the automatic dosing and stirring device for testing whether the component content of the rich MEG meets the actual working conditions, and a flow meter should be set after the conveying pump for verifying whether the flow meets the actual working conditions.

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