Water-based annulus protection fluid and preparation method thereof

Abstract

The invention discloses a water-based annulus protection liquid and a preparation method thereof, the protection liquid comprises the following components: 21-31% of alkylene quinoline quaternary ammonium salt, 5-11% of a high temperature bactericide, 5-15% of amino trimethylene phosphonic acid, 5-21% of a high temperature surfactant, and 41-51% of a solvent, and the preparation method comprises the following steps: uniformly mixing quinoline and alkylene benzyl chloride with the same amount; forming a mixture; and heating the mixture to 111 DEG C, and reacting for 7.5-11.5 hours while stirring at the rotating speed of 551-151rp7 to obtain the alkylene quinoline quaternary ammonium salt. The preparation method comprises the following steps: respectively weighing 21-31% of alkylene quinoline quaternary ammonium salt, 5-11% of high-temperature bactericide, 5-15% of amino trimethylene phosphonic acid, 5-21% of high-temperature surfactant and 41-51% of solvent, and fully and uniformly stirring at normal temperature to obtain the water-based annulus protection liquid additive. The prepared annulus protection liquid auxiliary agent has good solubility in a test medium, the corrosion rate of each material in the test medium is 0.087 mm / a, pitting corrosion and pitting corrosion are avoided, and the anti-corrosion effect is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of metal material protection, relates to a water-based annular space protection liquid, and also relates to a preparation method of the protection liquid. Background Art

[0002] With the continuous exploitation of oil and gas fields in my country, CO2 corrosion, H2S corrosion, oxygen corrosion, Cl - The failure problems of oil casing and tubing fracture and perforation caused by corrosion and bacterial corrosion are becoming more and more serious, especially in the annular environment containing dissolved oxygen, CO2 and high mineralization, the failure of oil pipe and casing damage caused by corrosion often occur. Adding protective fluid to the annulus of oil casing is one of the main ways to effectively solve the corrosion of oil casing and tubing. Commonly used annular protective fluids are divided into water-based and oil-based. Water-based annular protective fluids have been widely used in recent years due to their wide sources, low prices, and green environmental protection.

[0003] The preservatives of water-based annular protection fluids in my country often use imidazoline and its derivatives as the main agent, compounded with other effective ingredients. This type of annular protection fluid has a good corrosion inhibition effect, but its disadvantages are that it has an unpleasant odor, is easily hydrolyzed, and has a short effective period. At present, there are also many new corrosion inhibitors being developed, such as thiourea, diethylenetriamine and fatty acid reactions as the main agent. However, when there are too many unreacted fatty acids and thiourea in the synthetic raw materials of this type of annular protection fluid, the corrosion rate will be accelerated.

[0004] The Qinghai Oilfield is located in the extremely water-scarce Qinghai Plateau. There is a shortage of water resources for water-based annular protection fluid. At the same time, the bottom hole temperature of the Qinghai Oilfield is as high as over 180°C. Therefore, it is necessary to develop an ultra-high temperature water-based annular protection fluid that can utilize the water from Qinghai Lake. Summary of the invention

[0005] The purpose of the present invention is to provide a water-based annulus protection fluid to solve the technical problems of corrosion, fracture, perforation and the like of oil casing caused by ultra-high temperature conditions in the annulus environment containing dissolved oxygen, CO2 and high mineralization in the existing oil and gas well exploitation process.

[0006] Another object of the present invention is to provide a method for preparing the protective solution.

[0007] The technical solution adopted by the present invention is that the water-based annular space protection liquid auxiliary agent is composed of the following components in mass percentage: 20% to 30% of olefin quinoline quaternary ammonium salt, 5% to 10% of high-temperature bactericide, 5% to 15% of aminotrimethylene phosphonic acid, 5% to 20% of high-temperature surfactant, and 40% to 50% of solvent, and the sum of the mass percentages of the above components is 100%.

[0008] The present invention is also characterized in that the structure of the olefin quinoline quaternary ammonium salt is as follows:

[0009]

[0010] Wherein the R group is a C10-C18 straight monoolefin group;

[0011] The high temperature fungicide is a mixture of any one or more of penfluanil, prochloraz, cyprodinil, and boscalid in any proportion;

[0012] The solvent is one of ethylene glycol and dimethylformamide or a mixture of the two in any proportion.

[0013] Another technical solution adopted by the present invention is a method for preparing a water-based annular space protection liquid additive, comprising the following steps:

[0014] Step 1: uniformly mix quinoline and olefinylbenzyl chloride in a molar ratio of 1:1 to form a mixture;

[0015] Step 2: heating the mixture to 160° C. at a heating rate of 7 to 9° C. / min, stirring at a speed of 550 to 650 rpm, and reacting for 9.5 to 10.5 hours to obtain an olefin quinoline quaternary ammonium salt;

[0016] Step 3: Weigh 20-30% of olefin quinoline quaternary ammonium salt, 5-10% of high-temperature bactericide, 5-15% of aminotrimethylene phosphonic acid, 5-20% of high-temperature surfactant, and 40-50% of solvent respectively, and the sum of the mass percentages of the above components is 100%. Stir the raw materials of each component at room temperature to obtain a water-based annular space protection liquid additive.

[0017] The present invention is also characterized in that the high temperature bactericide is a mixture of any one or more of penfluanil, prochloraz, cyprodinil and boscalid in any proportion;

[0018] The solvent is one of ethylene glycol and dimethylformamide or a mixture of the two in any proportion.

[0019] The beneficial effects of the present invention are:

[0020] (1) The annular space protection liquid additive prepared by the present invention is simple and quick to produce, has good solubility in the test medium, has a slow corrosion rate of each material, has a uniform and dense adsorption film, has an obvious anti-corrosion effect, and has no pitting or pitting corrosion on the material protection;

[0021] (2) The annulus protection fluid additive for ultra-high temperature gas wells prepared by the present invention is a water-soluble annulus protection fluid anti-corrosion additive, which can be widely used in the anti-corrosion of oil casing in an environment where dissolved oxygen, CO2 and high mineralization coexist in an oil and gas annulus system with Qinghai Lake water as the base fluid. Adding a small amount of annulus protection fluid corrosion inhibitor can effectively control the corrosion of oil casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the reaction equation for preparing olefin quinoline quaternary ammonium salt in the present invention. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The water-based annular space protection liquid auxiliary agent is characterized in that it is composed of the following components in mass percentage: 20% to 30% of olefin quinoline quaternary ammonium salt, 5% to 10% of high-temperature bactericide, 5% to 15% of aminotrimethylene phosphonic acid, 5% to 20% of high-temperature surfactant, and 40% to 50% of solvent, and the sum of the mass percentages of the above components is 100%, wherein the olefin quinoline quaternary ammonium salt is the main agent, and the bactericide, scale inhibitor, high-temperature surfactant, and solvent are compounding agents. In the present invention, aminotrimethylene phosphonic acid is used as the high-temperature scale inhibitor.

[0025] The structure of the quaternary ammonium salt of olefin quinoline is shown below, wherein the R group is a C10-C18 straight-linked monoolefin group;

[0026]

[0027] The high temperature fungicide is a mixture of one or more of penfluanid, prochloraz, cyprodinil and boscalid in any proportion.

[0028] The solvent is one of ethylene glycol and dimethylformamide or a mixture of the two in any proportion.

[0029] The preparation method of the water-based annular space protection liquid additive comprises the following steps:

[0030] Step 1: uniformly mix quinoline and olefinylbenzyl chloride in a molar ratio of 1:1 to form a mixture;

[0031] Step 2: The mixture is heated to 160°C at a heating rate of 7-9°C / min, stirred at a speed of 550-650 rpm, and reacted for 9.5-10.5 hours to obtain an olefin quinoline quaternary ammonium salt, as shown in the reaction formula: Figure 1 As shown, the olefinylquinoline quaternary ammonium salt is a dark red viscous liquid;

[0032] Step 3: Weigh 20-30% of olefin quinoline quaternary ammonium salt, 5-10% of high-temperature bactericide, 5-15% of aminotrimethylene phosphonic acid, 5-20% of high-temperature surfactant, and 40-50% of solvent respectively, and the sum of the mass percentages of the above components is 100%. Stir the raw materials of each component at room temperature to obtain a water-based annular space protection liquid additive.

[0033] Aminotrimethylenephosphonic acid is used as a high-temperature scale inhibitor; the high-temperature bactericide is a mixture of one or more of penfluanil, prochloraz, cyprodinil, and boscalid in any proportion; the solvent is a mixture of one or two of ethylene glycol and dimethylformamide in any proportion.

[0034] In order to test the protective effect of the prepared annulus protection fluid additive for ultra-high temperature gas wells, a high-temperature and high-pressure autoclave was used to simulate the oil and gas well system environment to evaluate its anti-corrosion effect.

[0035] The test conditions are shown in Table 1, the water sample is the analysis result of Qinghai Lake salt water, as shown in Table 2, and the material of the coupon sample used is N80.

[0036] Table 1. Experimental conditions for evaluating additives for annular protection fluids for ultra-high temperature gas wells

[0037]

[0038] Table 2. Analysis results of Qinghai Lake water samples

[0039]

[0040] Example 1

[0041] Prepare the water-based annular space protection fluid additive according to the following steps:

[0042] Step 1: fully mixing quinoline and olefin benzyl chloride to form a mixture, wherein the molar ratio of quinoline to olefin benzyl chloride is 1:1, and the R group of the olefin group is a C10 direct olefin group;

[0043] Step 2: The mixture was heated to 160°C at a heating rate of 7°C / min, stirred at a speed of 550 pm, and reacted for 9.5 hours to obtain a dark red viscous liquid olefin quinoline quaternary ammonium salt;

[0044] Step 3: Weigh 30% of olefin quinoline quaternary ammonium salt, 5% of penfluthionil, 10% of aminotrimethylene phosphonic acid, 5% of high-temperature surfactant, and 50% of ethylene glycol solvent respectively, and stir the raw materials of each component at room temperature to obtain a water-based annular space protection liquid additive A.

[0045] The annulus protection fluid additive A prepared in this embodiment has good solubility in the test medium, and the corrosion rate of each material in the test medium is 0.072 mm / a, without pitting and pitting. The additive for annulus protection fluid for oil and gas wells obtained in this embodiment has obvious anti-corrosion effect.

[0046] Example 2

[0047] Prepare the water-based annular protection fluid additive for ultra-high temperature gas wells by following the steps below:

[0048] Step 1: fully and uniformly mix quinoline and olefinyl benzyl chloride to form a mixture, wherein the molar ratio of quinoline to olefinyl benzyl chloride is 1:1, and the R group of the olefinyl is a C14 direct olefin group;

[0049] Step 2: The mixture was heated to 160°C at a heating rate of 9°C / min, stirred at a speed of 600 rpm, and reacted for 10.5 hours to obtain a dark red viscous liquid olefin quinoline quaternary ammonium salt;

[0050] Step 3: Weigh 20% of olefin quinoline quaternary ammonium salt, 10% of boscalid, 15% of aminotrimethylenephosphonic acid, 15% of high-temperature surfactant, and 40% of dimethylformamide solvent respectively, and stir the raw materials of each component at room temperature to obtain a water-based annular space protection liquid additive B.

[0051] The annulus protection fluid additive B prepared in this embodiment has good solubility in the test medium, and the corrosion rate of each material in the test medium is 0.095 mm / a, without pitting and pitting. The additive for annulus protection fluid for oil and gas wells obtained in this embodiment has obvious anti-corrosion effect.

[0052] Example 3

[0053] Prepare the water-based annular protection fluid additive for ultra-high temperature gas wells by following the steps below:

[0054] Step 1: fully and uniformly mix quinoline and olefinyl benzyl chloride to form a mixture, wherein the molar ratio of quinoline to olefinyl benzyl chloride is 1:1, and the R group of the olefinyl is a C18 straight olefin group;

[0055] Step 2: The mixture was heated to 160°C at a heating rate of 8°C / min, stirred at a speed of 650 rpm, and reacted for 10 hours to obtain a dark red viscous liquid olefin quinoline quaternary ammonium salt;

[0056] Step 3: Weigh 25% of olefin quinoline quaternary ammonium salt, 7% of prochloraz, 5% of aminotrimethylenephosphonic acid, 20% of high-temperature surfactant, and 43% of dimethylformamide solvent respectively, and stir the raw materials of each component at room temperature to obtain a water-based annular space protection liquid additive C.

[0057] The annulus protection fluid additive C prepared in this embodiment has good solubility in the test medium, and the corrosion rate of each material in the test medium is 0.087 mm / a, without pitting and pitting. The additive for annulus protection fluid for oil and gas wells obtained in this embodiment has obvious anti-corrosion effect.

[0058] Comparative Example

[0059] Without adding annular protection liquid additives, the corrosion rate of different N 80 is 1.38mm / a, and the corrosion is relatively large. It can be seen that the annular protection liquid additive has excellent anti-corrosion effect.

[0060] The annulus protection fluid additive for ultra-high temperature gas wells obtained by the present invention is an anti-corrosion additive for water-soluble annulus protection fluid, and can be widely used in the anti-corrosion of dissolved oxygen, CO2 and high mineralization coexistence environment of oil casing in the oil and gas annulus system with Qinghai Lake water as the base fluid. The corrosion of the oil casing can be effectively controlled by adding 5% annulus protection fluid corrosion inhibitor. The additive is simple and quick to produce, has good water-soluble dispersibility, and has a uniform and dense adsorption film, and has no pitting corrosion, pitting corrosion, etc. for the protection of materials.

Claims

1. A water-based annular space protection liquid additive, characterized in that: The invention is composed of the following components in percentage by mass: 20% to 30% of olefin quinoline quaternary ammonium salt, 5% to 10% of high-temperature bactericide, 5% to 15% of aminotrimethylenephosphonic acid, 5% to 20% of high-temperature surfactant and 40% to 50% of solvent, and the sum of the percentages by mass of the above components is 100%.

2. The water-based annular space protection liquid additive according to claim 1, characterized in that: The structure of the olefin quinoline quaternary ammonium salt is shown below, wherein the R group is a C10-C18 straight-linked monoolefin group.

3. The water-based annular space protection liquid additive according to claim 1, characterized in that: The high temperature bactericide is a mixture of any one or more of penfluanil, prochloraz, cyprodinil and boscalid in any proportion.

4. The water-based annular space protection liquid additive according to claim 1, characterized in that: The solvent is one of ethylene glycol and dimethylformamide or a mixture of the two in any proportion.

5. A method for preparing a water-based annular space protection liquid additive, characterized in that: The following steps are involved: Step 1: uniformly mix quinoline and olefinylbenzyl chloride in a molar ratio of 1:1 to form a mixture; Step 2: heating the mixture to 160° C. at a heating rate of 7 to 9° C. / min, stirring at a speed of 550 to 650 rpm, and reacting for 9.5 to 10.5 hours to obtain an olefin quinoline quaternary ammonium salt; Step 3: Weigh 20-30% of olefin quinoline quaternary ammonium salt, 5-10% of high-temperature bactericide, 5-15% of aminotrimethylene phosphonic acid, 5-20% of high-temperature surfactant, and 40-50% of solvent respectively, and the sum of the mass percentages of the above components is 100%. Stir the raw materials of each component at room temperature to obtain a water-based annular space protection liquid additive.

6. The method for preparing the water-based annular space protection liquid additive according to claim 5, characterized in that: The high temperature bactericide is a mixture of any one or more of penfluanil, prochloraz, cyprodinil and boscalid in any proportion.

7. The method for preparing the water-based annular space protection liquid additive according to claim 5, characterized in that: The solvent is one of ethylene glycol and dimethylformamide or a mixture of the two in any proportion.

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