Medicament for treating collapse of electric field of electric dehydrator and preparation method of medicament

Abstract

The invention belongs to the field of oil field united station produced liquid treatment, and particularly discloses an electric dehydrator collapse electric field treatment agent and a preparation method thereof, and the electric dehydrator collapse electric field treatment agent comprises deionized water, a current stabilizer and an oil washing agent; the current stabilizer is one or more of penta (methylene diphosphonic acid), diethylene triamine penta (methylene phosphonic acid) and bis (1, 6-hexylidene triamine penta (methylene phosphonic acid); the oil washing agent is one or more of fatty alcohol polyoxyethylene ether AEO-9 and a fatty alcohol polyoxyethylene ether AEO-7 demulsifying agent; and the corrosion inhibitor is imidazoline. The invention also comprises a corrosion inhibitor, which is imidazoline. Compared with the prior art, the electric field collapse treatment agent for the electric dehydrator integrates the functions of oil-water separation and electric field stabilization, the electric dehydrator can run stably and does not collapse the electric field by adding one agent, and the water content in oil subjected to electric dehydration reaches the standard; the problem that the electric field of the electric dehydrator collapses can be solved by adding a small amount of chemicals, the workload of workers is reduced, and meanwhile production is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of treating produced liquid in oilfield gathering stations, and particularly to a chemical agent for treating the collapsed electric field of an electro-dehydrator and a preparation method thereof. Background Art

[0002] A certain gathering station in a certain block of Daqing Oilfield receives polymer flooding produced liquid, heavy oil, fracturing fluid and waste liquid, resulting in complex components of the incoming liquid at the inlet of the electro-dehydrator, serious emulsification, incomplete separation of asphaltene and impurities in the incoming liquid from the oil and water, thus causing their enrichment in the middle of the oil and water, forming an "intermediate transition layer" between the oil and water. Since the transition layer has a high water content and strong conductivity, when the transition layer between the electrode plates accumulates to a certain extent, it will cause electric breakdown of the electrode plates, resulting in the problem of collapsed electric field. The frequency of the collapsed electric field of the electro-dehydrator in this block of the gathering station is 2 - 3 times per day, and the water content of the exported oil does not meet the standard, seriously affecting the production operation.

[0003] Currently, the treatment method for the collapsed electric field is to transfer the transition layer and bottom water to the accident tank, and after sedimentation, pump it back into the electro-dehydration system. This method can temporarily alleviate the problem of the collapsed electric field, but it often causes three problems. First, the frequency of the collapsed electric field is 3 - 10 times per day. Frequent discharging of bottom water to the accident tank increases the workload of workers. Second, the oil produced after sedimentation of the discharged bottom water is pumped back into the gathering and transportation process and finally enters the electro-dehydrator. The transition layer in the electro-dehydrator accumulates in the electric field all the time, resulting in frequent occurrence of the collapsed electric field and inability to completely solve the problem of the collapsed electric field. Third, when the frequency of the collapsed electric field is too high, it will lead to poor treatment effect of the equipment, and the water content in the oil after electro-dehydration does not meet the standard, being higher than 0.5%. It is necessary to develop a new chemical agent which can make the electro-dehydrator operate stably for a long time after being added. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a chemical agent for treating the collapsed electric field of an electro-dehydrator and a preparation method thereof.

[0005] To achieve the above object, the present invention is implemented according to the following technical solution:

[0006] One object of the present invention is to provide a chemical agent for treating the collapsed electric field of an electro-dehydrator, which includes deionized water, a current stabilizer and an oil washing agent; the current stabilizer is one or more of pentamethylenediphosphonic acid, diethylenetriamine pentamethylenephosphonic acid and bis(1,6-hexamethylenetriamine) pentamethylenephosphonic acid; the oil washing agent is one or more of fatty alcohol polyoxyethylene ether AEO-9 and fatty alcohol polyoxyethylene ether AEO-7.

[0007] Further, it also includes a corrosion inhibitor, and the corrosion inhibitor is imidazoline.

[0008] Further, the chemical agent for treating the collapsed electric field of the electro-dehydrator is composed of diethylenetriamine pentamethylenephosphonic acid, fatty alcohol polyoxyethylene ether AEO-9, imidazoline and deionized water in a volume ratio of 15:55:10:80.

[0009] The second object of the present invention is to provide a preparation method of a chemical agent for treating the collapsed electric field of an electro-dehydrator, comprising the following steps: First, add deionized water to a reaction kettle, and while stirring, add a current stabilizer. After it is fully dissolved, add a washing oil agent and a corrosion inhibitor at one time. After stirring evenly, it can be discharged and canned to obtain the chemical agent for treating the collapsed electric field of the electro-dehydrator; or first add deionized water to the reaction kettle, and while stirring, add the current stabilizer. After it is fully dissolved, add the washing oil agent at one time. After stirring evenly, it can be discharged and canned to obtain the chemical agent for treating the collapsed electric field of the electro-dehydrator.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] (1) The chemical agent for treating the collapsed electric field of the electro-dehydrator of the present invention combines the functions of oil-water separation and stable electric field. Adding one chemical agent can achieve the stable operation of the electro-dehydrator, without the collapse of the electric field, and the water content in the oil after electro-dehydration meets the standard.

[0012] (2) The dosage of the chemical agent of the present invention is only 50-300 mg / L. Adding a small amount of the chemical agent can solve the problem of the collapse of the electric field of the electro-dehydrator, reducing the workload of workers and ensuring production at the same time.

[0013] (3) The present invention does not require special equipment and can be continuously added at the inlet of the electro-dehydrator, meeting the production requirements of combined stations of different scales. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the electro-dehydration process of the electro-dehydrator to which the chemical agent of Example 1 is added.

[0015] Figure 2 It is the physical diagram after electro-dehydration of the transition layer after adding the chemical agent of Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the objects, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the embodiments. The specific embodiments described here are only used to explain the present invention and are not used to limit the invention.

[0017] Example 1

[0018] Take diethylenetriamine pentamethylene phosphonic acid, fatty alcohol polyoxyethylene ether AEO-9, imidazoline and deionized water according to the volume ratio of 15:55:10:80. First, add deionized water to a reaction kettle, and while stirring, add diethylenetriamine pentamethylene phosphonic acid. After it is fully dissolved, add fatty alcohol polyoxyethylene ether AEO-9 and imidazoline at one time. After stirring evenly, it can be discharged and canned to obtain Sample 1 of the chemical agent for treating the collapsed electric field of the electro-dehydrator.

[0019] To verify the feasibility of the agent of the present invention, an agent for treating the collapsed electric field of the electro-dehydrator is added at the inlet of the electro-dehydrator, and the electric dewatering current, operating status and water content of the oil outlet of the electro-dehydrator are monitored. The specific operation steps are as follows:

[0020] Step 1: Add 300 mL of the transition layer into the electro-decanter. After tightening the lid, connect it to the high-voltage wire and the ground wire respectively. The electro-dehydration parameters are set as voltage 1 kV, frequency 1 kHz, duty cycle 35%, and constant current value 10 A. Click the start button to perform the electro-dehydration characteristic detection.

[0021] Step 2: The electro-dehydration lasts for 1 h, and the voltage and current are recorded every 30 s.

[0022] Step 3: After the electro-dehydration experiment is completed, detect the water content of the oil.

[0023] Step 4: Add the agent for treating the collapsed electric field of the electro-dehydrator into the transition layer, mix evenly, and the dosing concentration is 300 mg / L. Click the start button to perform the electro-dehydration characteristic detection.

[0024] Step 5: The electro-dehydration lasts for 1 h, and the voltage and current are recorded every 30 s.

[0025] Step 6: After the electro-dehydration experiment is completed, detect the water content of the oil.

[0026] Step 7: Compare the current during the electro-dehydration process in the transition layer with the electro-dehydration current after adding the agent for treating the collapsed electric field of the electro-dehydrator, and calculate the current decline rate.

[0027] Step 8: Compare the water content after electro-dehydration in the transition layer with the water content after electro-dehydration with the agent for treating the collapsed electric field of the electro-dehydrator, and check whether the requirement of water content < 0.5% is met.

[0028] The electro-dehydration process of the electro-dehydrator with the addition of Sample 1 of the agent for treating the collapsed electric field of the electro-dehydrator is as Figure 1 shown, and the physical diagram after electro-dehydration of the transition layer after adding Sample 1 of the agent for treating the collapsed electric field of the electro-dehydrator is as Figure 2 shown. From Figure 1 , Figure 2 it can be seen that after the electro-dehydration is started, the electro-dehydration current gradually rises to 10 A, and after 10 min, the current gradually decreases and finally stabilizes at 0.5 A. The voltage gradually rises and stabilizes at 1 kV. During the 1 h of electro-dehydration, there is no boiling phenomenon in the oil product, and the electro-dehydration operation is stable. After electro-dehydration, obvious water separation can be seen in the tank. Take the upper-layer oil for water content detection in the oil, and the water content is 0.29%, which meets the standard of water content < 0.5%. It shows that the agent for treating the collapsed electric field of the heavy oil electro-dehydrator can solve the problem of unstable electro-dehydration operation and can make the water content of the oil product at the electro-dehydration outlet lower than 0.5%.

[0029] Application Example 1

[0030] (1) Add the sample 1 of the electric dehydration unit cross - electric - field treatment agent at the inlet of the on - site electric dehydration unit, starting from October 2. In the first week of the initial dosing period, the dosing amount is 650 - 800 kg per day. After stabilizing through large - dose treatment, the frequency of cross - electric - field drops from 2 - 3 times per day to basically no cross - electric - field, and the asphaltene content drops from 8% to 2.6%. In the second week of dosing, the amount is gradually reduced to 750 kg per day, 600 kg per day, and 200 kg per day. On October 23, the dosing amount is reduced to 175 kg and the dosing stops on the 24th, as shown in Table 1.

[0031] Table 1

[0032]

[0033]

[0034] (2) After nearly a month of agent treatment, the electric dehydration has achieved stable operation, and there has been no serious cross - electric - field situation for 15 consecutive days. During the dosing period of the agent, the front - end production system operates normally, and there is no situation of heavy oil production suspension or reduction of external output. After the dosing ends, the electric field remains stable within one week.

[0035] (3) When the original demulsifier on - site is redosed, the cross - site phenomenon appears again.

[0036] As can be seen from Table 1, the on - site electric dehydration unit still has the problem of cross - electric - field every day at the initial stage of adding the cross - electric - field treatment agent for heavy oil electric dehydration. With the dosing of the agent and the increase of the effective concentration of the agent, the electric field gradually stabilizes, and cross - electric - field no longer occurs. The water content at the oil outlet also gradually drops from the original 2.95% to 0.09%. After the dosing of the cross - electric - field treatment agent for heavy oil electric dehydration stops, there is no cross - electric - field for 7 consecutive days, and then cross - electric - field appears. When the original on - site agent is added, the cross - electric - field problem is not alleviated, and the water content at the oil outlet also increases. It shows that the cross - electric - field treatment agent for heavy oil electric dehydration can effectively solve the problem of cross - electric - field of heavy oil electric dehydration units, and at the same time ensure that the water content at the oil outlet of the electric dehydration unit is <0.5%.

[0037] In summary, the cross - electric - field treatment agent of the electric dehydration unit of the present invention combines the functions of oil - water separation and stable electric field. Adding one agent can achieve the stable operation of the electric dehydration unit, no cross - electric - field, and the water content in the oil after electric dehydration meets the standard; and adding a small amount of the agent can solve the problem of cross - electric - field of the electric dehydration unit.

[0038] The technical solution of the present invention is not limited to the limitations of the above - mentioned specific embodiments. Any technical deformation made according to the technical solution of the present invention falls within the protection scope of the present invention.

Claims

1. A chemical for treating electric field collapse in an electric dehydrator, characterized in that: It includes deionized water, a current stabilizer and an oil washing agent; the current stabilizer is one or more of penta (methylene diphosphonic acid), diethylene triamine penta (methylene phosphoric acid) and di-1,6-hexamethylene triamine penta (methylene phosphonic acid); the oil washing agent is one or more of fatty alcohol polyoxyethylene ether AEO-9 and fatty alcohol polyoxyethylene ether AEO-7.

2. The electric field collapse treatment agent for electric dehydrators according to claim 1, characterized in that: The invention also comprises a corrosion inhibitor, wherein the corrosion inhibitor is imidazoline.

3. The electric field collapse treatment agent for electric dehydrators according to claim 2, characterized in that: It is composed of diethylenetriamine penta (methylene phosphoric acid), fatty alcohol polyoxyethylene ether AEO-9, imidazoline and deionized water in a volume ratio of 15:55:10:

80.

4. A method for preparing the electric field collapse treatment agent for electric dehydrators as claimed in claim 3, characterized in that: The following steps are involved: First add deionized water into the reactor, add the current stabilizer while stirring, add the oil remover and corrosion inhibitor at once after they are fully dissolved, and after stirring evenly, discharge the material into the tank to obtain the electric dehydrator electric field collapse control agent.

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