A composite treatment system for produced water in a gas well

Abstract

The present application discloses a composite treatment system for gas well produced water. During the pre-treatment period, the injection amounts of the first chemical agent and the second chemical agent and the temperature parameter are detected, and the temperature is monitored in real time throughout the pre-treatment period. Based on the judgment relationship of the magnitudes of the set thresholds, the magnitude relationship between the initial injection value and the reference injection threshold is determined, and the injection amount of the flocculant is reasonably selected according to the determined magnitude relationship. Thus, the composite treatment system comprehensively considers the injection amounts of the first chemical agent and the second chemical agent and the temperature range to reasonably select the flocculant that needs to be increased subsequently, thereby realizing the reasonable selection of chemicals during the composite chemical precipitation treatment of gas well produced water, and further realizing the composite treatment of different chemical precipitation agents, improving the precipitation treatment performance of gas well produced water.

Description

Technical Field

[0001] This application relates to the technical field of the treatment of produced water from gas wells, and particularly to a composite treatment system for produced water from gas wells. Background Art

[0002] The composite treatment of produced water from gas wells is an important process aimed at effectively treating the water produced from gas wells to meet environmental protection requirements and improve resource utilization efficiency. The produced water from gas wells usually has the following characteristics: High salinity: It contains a large amount of dissolved salts, such as sodium chloride, calcium chloride, etc. It contains harmful substances: It may contain harmful substances to the environment such as hydrogen sulfide, heavy metal ions, etc. Complexity: The water quality components are complex, and the water quality of the produced water from different gas wells varies greatly.

[0003] The produced water from gas wells usually contains various harmful substances, such as heavy metals (such as mercury, cadmium, lead, etc.), salts, and a small amount of petroleum substances, etc. If directly discharged without treatment, it will cause serious pollution to soil, surface water, groundwater, etc., and damage the ecological environment. Treating the produced water from gas wells can effectively remove these harmful substances and reduce the harm to the environment. Moreover, substances such as salts in the produced water accumulate in pipelines and equipment, which will cause corrosion and scaling. Corrosion will reduce the service life of pipelines and equipment, increase maintenance costs, and may even cause safety accidents such as leakage. Scaling will reduce the flow cross-sectional area of pipelines and reduce the production efficiency of gas wells. Treating the produced water can remove these corrosive and scaling substances and protect the production equipment.

[0004] For the produced water from gas wells, chemical precipitation methods are usually used for treatment. Among them, by adding chemical agents to the produced water, harmful substances in the water form precipitates, thereby realizing the separation of water and pollutants.

[0005] However, when using different chemical agents for composite treatment, if the usage sequence or usage method of different chemical agents is not adjusted, it will seriously affect the precipitation effect of the produced water from gas wells, and even produce more serious or complex compounds, and increase the waste and side effects of chemical precipitation agents. Summary of the Invention

[0006] In an exemplary embodiment of this application, a composite treatment system for produced water from gas wells is provided to achieve the composite treatment of different chemical precipitation agents and improve the precipitation treatment performance of the produced water from gas wells.

[0007] The present application provides a composite treatment system for gas well produced water, comprising: a pre-treatment unit: configured to obtain a first chemical injection amount within a first time period during a pre-treatment cycle, obtain a second chemical injection amount within a second time period during the pre-treatment cycle, the first time period being prior to the second time period within the pre-treatment cycle, and obtain a plurality of temperature parameters within the first time period and the second time period, and take the average value of the plurality of temperature parameters as the average temperature parameter;

[0008] A judgment processing unit: configured to judge the magnitude relationship between the first chemical injection amount and a first chemical threshold, judge the magnitude relationship between the second chemical injection amount and a second chemical threshold, and judge the magnitude relationship between the average temperature parameter and a temperature parameter threshold;

[0009] A flocculant judgment unit: configured to, if the first chemical injection amount is greater than the first chemical threshold, increase an initial injection value with a first injection parameter, otherwise maintain the initial injection value unchanged; if the second chemical injection amount is greater than the second chemical threshold, increase the initial injection value with the first injection parameter, otherwise maintain the initial injection value unchanged; if the average temperature parameter is less than the temperature parameter threshold, increase the initial injection value with a second injection parameter, otherwise maintain the initial injection value unchanged, wherein the second injection parameter is greater than the first injection parameter;

[0010] A flocculant injection unit: after comparing the first chemical injection amount, the second chemical injection amount, and the average temperature parameter with the first chemical threshold, the second chemical threshold, and the temperature parameter threshold respectively, judge the magnitude relationship between the initial injection value and a reference injection threshold. If the initial injection value is greater than the reference injection threshold, inject with a first flocculant injection amount, otherwise, inject with a second flocculant injection amount, and the first flocculant injection amount is greater than the second flocculant injection amount.

[0011] Further, after comparing the first chemical injection amount, the second chemical injection amount, and the average temperature parameter with the first chemical threshold, the second chemical threshold, and the temperature parameter threshold respectively, the initial injection value is determined by the cumulative value of the second injection parameter or the first injection parameter.

[0012] Further, the second injection parameter is twice the first injection parameter.

[0013] Further, the initial injection value is 0, and both the first injection parameter and the second injection parameter are greater than 0.

[0014] Further, the first chemical injection amount is the injection amount of a first chemical, and the first chemical is sodium hydroxide or calcium hydroxide.

[0015] Further, the injection amount of the second agent is the injection amount of the second agent, and the second agent is sodium carbonate.

[0016] Further, the first agent threshold, the second agent threshold, the temperature parameter threshold, and the reference injection threshold are stored in the controller.

[0017] The embodiments of the present application have the following beneficial effects: During the pre-treatment period, the injection amounts of the first agent and the second agent and the temperature parameters are detected, and the temperature is monitored in real time throughout the pre-treatment period. Based on the magnitude judgment relationship of the set thresholds, the magnitude relationship between the initial injection value and the reference injection threshold is determined, and the injection amount of the flocculant is reasonably selected according to the determined magnitude relationship. Thus, the composite treatment system comprehensively considers the injection amounts of the first agent and the second agent and the temperature range to reasonably select the flocculant to be added subsequently, thereby realizing the reasonable selection of chemicals for the composite chemical precipitation treatment of the produced water from the gas well, and further realizing the composite treatment of different chemical precipitation agents, and improving the precipitation treatment performance of the produced water from the gas well. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 Exemplarily shows a system schematic diagram of a composite treatment system for the produced water from a gas well provided by an embodiment of the present application. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application.

[0021] To further illustrate the technical solutions provided by the embodiments of the present application, the following will describe them in detail with reference to the drawings and specific embodiments. Although the embodiments of the present application provide the operation steps of the composite treatment system as shown in the following embodiments or drawings, based on routine or non-creative efforts, the composite treatment system may include more or fewer operation steps. In the steps where there is no necessary causal relationship logically, the execution order of these steps is not limited to the execution order provided by the embodiments of the present application.

[0022] Reference Figure 1As shown in the figure, the present application provides a composite treatment system for gas well produced water, including a pre-treatment unit 100, a judgment and treatment unit 200, a flocculant judgment unit 300, and a flocculant injection unit 400.

[0023] The pre-treatment unit 100 is used to obtain the injection amount of the first chemical agent in the first time period within the pre-treatment cycle, and obtain the injection amount of the second chemical agent in the second time period within the pre-treatment cycle.

[0024] Among them, the injection amount of the first chemical agent is the injection amount of the first chemical agent, and the first chemical agent is sodium hydroxide or calcium hydroxide. When treating gas well produced water, sodium hydroxide or calcium hydroxide can be added first to adjust the pH value, so that some heavy metal ions form hydroxide precipitates.

[0025] The injection amount of the second chemical agent is the injection amount of the second chemical agent, and the second chemical agent is sodium carbonate. Sodium carbonate is added to remove the hardness ions in the gas well produced water.

[0026] The first time period is in the pre-order of the second time period within the pre-treatment cycle. That is to say, when pre-treating the gas well produced water, the first chemical agent is first injected in the first time period to adjust the acidity and alkalinity. After injecting the first chemical agent, when the pH of the gas well produced water reaches 7, the injection of the first chemical agent is stopped and the injection amount of the first chemical agent that has been injected at this time is used as the injection amount of the first chemical agent.

[0027] After completing the injection of the first chemical agent, enter the second time period of the pre-treatment cycle, and start injecting the second chemical agent. When determining the injection amount of the second chemical agent, a comprehensive water quality analysis of the gas well produced water can be carried out to determine the concentration of the hardness ions (such as calcium and magnesium ions) that need to be removed therein. This is the basis for calculating the injection amount of sodium carbonate, that is, the basis for calculating the injection amount of the second chemical agent, and the injection amount of the second chemical agent is determined.

[0028] Obtain multiple temperature parameters in the first time period and the second time period, and use the average value of the multiple temperature parameters as the average temperature parameter. The temperature parameter is the temperature of the gas well produced water that needs to be subjected to composite treatment. The multiple temperature parameters can be determined by performing multi-point interval detection in the first time period and the second time period.

[0029] The judgment processing unit 200 is used to judge the magnitude relationship between the first chemical injection amount and the first chemical threshold, judge the magnitude relationship between the second chemical injection amount and the second chemical threshold, and judge the magnitude relationship between the average temperature parameter and the temperature parameter threshold. The first chemical threshold, the second chemical threshold, the temperature parameter threshold, and the reference injection threshold are stored in the controller. By judging the magnitude relationships between the first chemical injection amount and the first chemical threshold, the second chemical injection amount and the second chemical threshold, and the average temperature parameter and the temperature parameter threshold, the injection amount of the flocculant in the subsequent processing stage can be determined, providing theoretical guidance for the injection of the flocculant and avoiding operational problems such as low efficiency or inaccurate injection amount caused by determining the injection of the flocculant through experience.

[0030] The flocculant judgment unit 300 is used to increase the initial injection value with the first injection parameter if the first chemical injection amount is greater than the first chemical threshold, otherwise maintain the initial injection value unchanged. If the second chemical injection amount is greater than the second chemical threshold, increase the initial injection value with the first injection parameter, otherwise maintain the initial injection value unchanged.

[0031] If the average temperature parameter is less than the temperature parameter threshold, increase the initial injection value with the second injection parameter, otherwise maintain the initial injection value unchanged, where the second injection parameter is greater than the first injection parameter.

[0032] Specifically, the initial injection value is the judgment basis for evaluating the subsequent increase of the flocculant. By accumulating the initial injection value, its magnitude relationship with the reference injection threshold is judged, and the first flocculant injection amount or the second flocculant injection amount is selected for effective injection. Among them, both the first flocculant injection amount and the second flocculant injection amount are the initial injection amounts of the flocculant. The user can selectively increase the flocculant or stop increasing the flocculant according to the flocculation precipitation situation after adding the flocculant. By reasonably selecting the injection amount of the initial flocculant, the processing efficiency of the flocculant during injection can be effectively improved, preventing the failure to achieve effective precipitation after multiple increases of the flocculant, or the generation of large precipitation when the flocculant is increased for the first time.

[0033] After comparing the first chemical injection amount, the second chemical injection amount, and the average temperature parameter with the first chemical threshold, the second chemical threshold, and the temperature parameter threshold respectively, the flocculant injection unit 400 judges the magnitude relationship between the initial injection value and the reference injection threshold. After comparing the first chemical injection amount, the second chemical injection amount, and the average temperature parameter with the first chemical threshold, the second chemical threshold, and the temperature parameter threshold respectively, the initial injection value is determined by the cumulative value of the second injection parameter or the first injection parameter.

[0034] If the initial injection value is greater than the reference injection threshold, injection is carried out at the first flocculant injection rate. This indicates that either the injection rate of the first chemical or the second chemical is relatively high, or the current temperature is relatively low, and more flocculant is required for injection to improve the flocculation effect. Specifically, a relatively low current temperature indicates that the temperature of the gas well produced water to be mixed and treated is relatively low, and a smaller amount of flocculant may result in a lower flocculation precipitation effect. Therefore, it is necessary to increase the amount of flocculant used and carry out injection at the first flocculant injection rate.

[0035] If the initial injection value is less than or equal to the reference injection threshold, injection is carried out at the second flocculant injection rate, and the first flocculant injection rate is greater than the second flocculant injection rate. This indicates that either the injection rate of the first chemical or the second chemical is relatively low, or the current temperature is relatively high, and less flocculant is required for injection to improve the flocculation effect. Specifically, a relatively high current temperature indicates that the temperature of the gas well produced water to be mixed and treated is relatively high. Therefore, only a smaller amount of flocculant is required to achieve a better flocculation effect under the current relatively high temperature condition, without causing waste of flocculant.

[0036] When adding the flocculant, it is added after the reaction of other precipitants is basically completed. This can avoid unnecessary reactions between the flocculant and other precipitants, and at the same time ensure that the flocculant can effectively aggregate the already formed precipitates into larger particles, facilitating subsequent solid-liquid separation, and preventing the formation of more complex compounds by some ions that could originally be removed by hydroxide or carbonate precipitation, which may affect the precipitation effect.

[0037] The second injection parameter is twice the first injection parameter. The initial injection value is 0, and both the first injection parameter and the second injection parameter are greater than 0.

[0038] Specifically, the initial injection value is 0, both the first injection parameter and the second injection parameter are greater than 0, and the second injection parameter is twice the first injection parameter.

[0039] For example, if the first injection parameter is 2 and the second injection parameter is 4, and if the injection rate of the first chemical is greater than the first chemical threshold, the injection rate of the second chemical is less than the second chemical threshold, and the average temperature parameter is greater than the temperature parameter threshold, then the initial injection value is determined to be 2 based on one first injection parameter.

[0040] If the injection rate of the first chemical is less than the first chemical threshold, the injection rate of the second chemical is greater than the second chemical threshold, and the average temperature parameter is less than the temperature parameter threshold, then the initial injection value is determined to be 6 by adding one first injection parameter and one second injection parameter.

[0041] If the injection amount of the first agent is greater than the first agent threshold, the injection amount of the second agent is greater than the second agent threshold, and the average temperature parameter is less than the temperature parameter threshold, then the initial injection value is determined as 8 by accumulating two first injection parameters and one second injection parameter.

[0042] If the injection amount of the first agent is less than the first agent threshold, the injection amount of the second agent is less than the second agent threshold, and the average temperature parameter is less than the temperature parameter threshold, then the initial injection value is determined as 4 by accumulating only one second injection parameter.

[0043] During the pre-treatment period, the injection amount of the first agent, the injection amount of the second agent, and the temperature parameter are detected, and the temperature is monitored in real time throughout the pre-treatment period. Based on the comparison relationship of the set thresholds, the size relationship between the initial injection value and the reference injection threshold is determined, and the injection amount of the flocculant is reasonably selected according to the determined size relationship. Thus, the composite treatment system comprehensively considers the injection amounts of the first agent and the second agent and the temperature range to reasonably select the flocculant to be added subsequently, thereby realizing the reasonable selection of agents during the composite chemical precipitation treatment of the gas well produced water, and further realizing the composite treatment of different chemical precipitation agents, improving the precipitation treatment performance of the gas well produced water.

[0044] Those skilled in the art should understand that the embodiments of the present application can be provided as a composite treatment system, a system, or a computer program product. Therefore, the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0045] The present application is described with reference to the flowcharts and / or block diagrams of the composite treatment system, device (system), and computer program product according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0046] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions specified in one or more processes and / or blocks Figure 1 one or more processes and / or blocks Figure 1 specified in one or more blocks or blocks.

[0047] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more processes and / or blocks Figure 1 one or more processes and / or blocks Figure 1 specified in one or more blocks or blocks.

[0048] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these modifications and variations.

Claims

1. A composite treatment system for the produced water of a gas well, characterized in that Including: Pre-treatment unit: used to obtain the first chemical injection amount within the first time period during the pre-treatment cycle, obtain the second chemical injection amount within the second time period during the pre-treatment cycle, the first time period is in the pre-order of the second time period within the pre-treatment cycle, obtain multiple temperature parameters within the first time period and the second time period, and take the average value of the multiple temperature parameters as the average temperature parameter. Wherein, the first chemical injection amount is the injection amount of the first chemical, the first chemical is sodium hydroxide or calcium hydroxide, the second chemical injection amount is the injection amount of the second chemical, and the second chemical is sodium carbonate; Judgment processing unit: used to judge the size relationship between the first chemical injection amount and the first chemical threshold, judge the size relationship between the second chemical injection amount and the second chemical threshold, and judge the size relationship between the average temperature parameter and the temperature parameter threshold; Flocculant judgment unit: if the first chemical injection amount is greater than the first chemical threshold, increase the initial injection value with the first injection parameter, otherwise keep the initial injection value unchanged; if the second chemical injection amount is greater than the second chemical threshold, increase the initial injection value with the first injection parameter, otherwise keep the initial injection value unchanged; if the average temperature parameter is less than the temperature parameter threshold, increase the initial injection value with the second injection parameter, otherwise keep the initial injection value unchanged, wherein the second injection parameter is greater than the first injection parameter; Flocculant injection unit: after comparing the first chemical injection amount, the second chemical injection amount and the average temperature parameter with the first chemical threshold, the second chemical threshold and the temperature parameter threshold respectively, judge the size relationship between the initial injection value and the reference injection threshold. If the initial injection value is greater than the reference injection threshold, inject with the first flocculant injection amount, otherwise, inject with the second flocculant injection amount. The first flocculant injection amount is greater than the second flocculant injection amount.

2. The composite processing system according to claim 1, wherein After comparing the first chemical injection amount, the second chemical injection amount and the average temperature parameter with the first chemical threshold, the second chemical threshold and the temperature parameter threshold respectively, the initial injection value is determined by the cumulative value of the second injection parameter or the first injection parameter.

3. The composite processing system according to claim 2, characterized in that, The second injection parameter is twice the first injection parameter.

4. The composite processing system according to claim 3, characterized in that, The initial injection value is 0, and both the first injection parameter and the second injection parameter are greater than 0.

5. The composite processing system according to claim 1, wherein The first chemical threshold, the second chemical threshold, the temperature parameter threshold and the reference injection threshold are stored in the controller.

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