Organic weak acid type jam releasing working solution

Abstract

The invention discloses an organic weak acid type jam releasing working solution which comprises the following raw materials in percentage by mass: 5%-7% of hydrochloric acid, 7%-9% of hydrofluoric acid, 24%-26% of water, 0.9%-1.1% of a corrosion inhibitor, 1.9%-2.1% of plastic pellets and 57.5%-59.5% of acetic acid. The plugging agent mainly comprises hydrochloric acid, hydrofluoric acid, water, a corrosion inhibitor, plastic balls and acetic acid, acid liquor reacts with quartz, clay, calcareous substances and the like in rocks to dissolve obstructions near a sticking point or reduce the volume of the obstructions, and the inert solid plastic balls are utilized to avoid acid corrosion and can enter a drilling tool and a mud cake interface along with sticking releasing liquid, so that friction resistance is reduced, and the plugging effect is improved. Organic corrosion inhibitor molecules contain amino groups, hydroxyl groups, sulfydryl groups and other polar groups, a coordination chelate film is formed by the organic corrosion inhibitor molecules and metal surface ions to play a protection role, a stuck drilling tool is soaked in a stuck releasing working solution prepared by taking acetic acid as basic acid, and the purposes of dissolving mudstone falling blocks and releasing the drilling tool are achieved. Therefore, the organic weak acid type jam releasing working solution is used for releasing a stuck drilling tool.

Description

Technical Field

[0001] The present invention belongs to the technical field of pickling and pipe sticking release agents, and specifically relates to an organic weak acid type pipe sticking release working fluid. Background Art

[0002] Mudstone is a rock with strong plasticity, and there are many gaps and pores between its particles. When the drill bit enters the mudstone layer, due to the rotation and impact of the drill bit, the cuttings will be carried to the bottom of the well. These cuttings will combine with the mud and block the drill pipe and drilling equipment, resulting in the drill pipe being stuck and unable to continue the drilling operation. In order to enable the drilling equipment to smoothly get out of the stuck state, pickling and pipe sticking release operation needs to be carried out on the drilling equipment.

[0003] At present, hydrochloric acid systems are generally used for pickling and pipe sticking release operations at home and abroad. Usually, hydrochloric acid with a concentration of 15% is selected. However, in the process of acid pickling and pipe sticking release in many oilfields such as Tarim Oilfield in China, there are problems that the reaction rate of hydrochloric acid changes greatly with the change of concentration and temperature, and the temperature and concentration change constantly during the reaction. Therefore, the reaction progress cannot be predicted, and the best timing for pipe sticking release is often missed, resulting in the failure of pipe sticking release.

[0004] Therefore, in view of the geological conditions in the Songliao Basin and the Daqing area, when using acid pickling and pipe sticking release fluid for pipe sticking release, there are still problems to be solved, such as drill string corrosion, difficulty in controlling the reaction rate of the pipe sticking release fluid, and the need to optimize and improve the slow release and isolation ability of the pipe sticking release fluid. Therefore, we need to propose an organic weak acid type pipe sticking release working fluid to solve the problems of drill string corrosion, difficulty in controlling the reaction rate of the pipe sticking release fluid, and poor pipe sticking release effect mentioned above. Summary of the Invention

[0005] The purpose of the present invention is to provide an organic weak acid type pipe sticking release working fluid, which is an organic weak acid type pipe sticking release working fluid that soaks the stuck drill string with a pipe sticking release working fluid prepared with acetic acid as the base acid to dissolve the mudstone chips and thus release the stuck drill string, so as to solve the problems mentioned in the above background art.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The organic weak acid type pipe sticking release working fluid, by mass percentage, comprises the following raw materials: 5%-7% hydrochloric acid, 7%-9% hydrofluoric acid, 24%-26% water, 0.9%-1.1% corrosion inhibitor, 1.9%-2.1% plastic balls, 57.5%-59.5% acetic acid, and the corrosion inhibitor is set to be one of quaternary ammonium salts, Mannich bases, and imidazolines.

[0008] Preferably, by mass percentage, it comprises the following raw materials: 6% hydrochloric acid, 8% hydrofluoric acid, 25% water, 1% corrosion inhibitor, 2% plastic balls, and 58% acetic acid.

[0009] Preferably, the acetic acid is set to be one of calcium acetate, iron acetate and magnesium acetate.

[0010] Preferably, the hydrofluoric acid is generated by reacting bromine water with potassium fluoride or ammonium hydride as raw materials, and the reaction equation is HBr + KF → HF + KBr.

[0011] Preferably, the plastic balls are inert solids. The plastic balls are prepared from polyethylene or polypropylene as raw materials. The polyethylene and polypropylene materials are cut into small particles, and then the cut small particles are put into a special melting machine or melting furnace. The temperature and heating time are set to melt the small particles into a liquid state. Finally, at the outlet of the melting machine or above the melting liquid surface, the molten plastic liquid is dripped to form balls.

[0012] Preferably, the quaternary ammonium salt is a product obtained by reacting a quaternary ammonium reagent with an alcohol solvent to form a mixture, and then purifying the mixture by filtration.

[0013] Preferably, the quaternary ammonium reagent is set to be one of methylammonium iodide, methylammonium bromide, trimethylsulfonium bromide and bromoalkane.

[0014] Preferably, the Mannich base is synthesized by reacting an amine, a ketone or an aldehyde nucleophile under alkaline conditions. The lone pair electrons of the coordinating atoms in the Mannich base enter the hybrid empty orbitals of Fe 3+ to form a coordination bond, and a complexation reaction occurs to generate a stable cyclic chelate adsorbed on the metal surface, forming a stable hydrophobic protective film, thereby preventing the diffusion of Fe 3+ generated by corrosion into the solution to achieve the purpose of metal corrosion inhibition.

[0015] Preferably, the imidazoline is obtained by reacting an ethanolamine reagent and dimethylimidazole in a dry reaction chamber under nitrogen protection to obtain a reaction product, then purifying and crystallizing the reaction product to obtain crystalline particles, and finally drying the crystalline particles to obtain imidazoline.

[0016] Based on the above-described organic weak acid type pipe sticking release working fluid, the present invention also provides a preparation method of an organic weak acid type pipe sticking release working fluid, including the following steps:

[0017] S1. Place hydrochloric acid and hydrofluoric acid in a reaction vessel in proportion and mix them to react to obtain a mixture;

[0018] S2. Slowly add water to the mixture and stir it with a magnetic stirrer to obtain a mixed solution;

[0019] S3. Add an inhibitor and plastic balls to the mixed solution and continue to stir to obtain a reaction mixed solution;

[0020] S4. Add acetic acid to the reaction mixture for reaction to obtain a reaction mixture.

[0021] S5. Filter the reaction mixture to remove impurities and solid particles in the reaction mixture, and the obtained liquid is the pipe sticking release working fluid.

[0022] The organic weak acid type pipe sticking release working fluid proposed by the present invention has the following advantages compared with the prior art:

[0023] 1. The organic weak acid type pipe sticking release working fluid of the present invention is mainly composed of hydrochloric acid, hydrofluoric acid, water, corrosion inhibitor, plastic balls and acetic acid. It uses the acid solution to react with quartz, clay, calcareous substances, etc. in the rock to dissolve or reduce the volume of the blockage near the sticking point. The inert solid plastic balls are used to avoid being corroded by the acid and can enter the interface between the drill string and the mud cake together with the pipe sticking release fluid, reducing the friction resistance and increasing the torque. The organic corrosion inhibitor molecule contains polar groups such as amino, hydroxyl, and mercapto groups, and plays a protective role by forming a coordination chelate film with metal surface ions. By soaking the stuck drill string with the pipe sticking release working fluid configured with acetic acid as the base acid, it can dissolve the mudstone chips and thus release the stuck drill string, which is an organic weak acid type pipe sticking release working fluid.

[0024] 2. The organic weak acid type pipe sticking release working fluid of the present invention uses hydrochloric acid, hydrofluoric acid, water, corrosion inhibitor, plastic balls, and acetic acid as raw materials. First, hydrochloric acid and hydrofluoric acid are placed in a reaction vessel in proportion for mixing reaction to obtain a mixture. Water is slowly added to the mixture and stirred with a magnetic stirrer to obtain a mixed solution. A corrosion inhibitor and plastic balls are added to the mixed solution and stirred continuously to obtain a reaction mixture. Acetic acid is added to the reaction mixture for reaction to obtain a reaction mixture. The reaction mixture is filtered to remove impurities and solid particles in the reaction mixture, and the obtained liquid is the pipe sticking release working fluid. It has a unique and reasonable concept, strong applicability, high performance, economic and environmental protection, reliable construction, and a high pipe sticking release success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart for the preparation of the organic weak acid type pipe sticking release working fluid of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1

[0028] The present invention provides an organic weak acid type pipe sticking releasing working fluid, which comprises the following raw materials by mass percentage: 6% hydrochloric acid, 8% hydrofluoric acid, 25% water, 1% corrosion inhibitor, 2% plastic balls, and 58% acetic acid. The organic weak acid type pipe sticking releasing working fluid is mainly composed of hydrochloric acid, hydrofluoric acid, water, corrosion inhibitor, plastic balls and acetic acid. By reacting the acid solution with quartz, clay, calcareous substances, etc. in the rock, the blockage near the sticking point is dissolved or reduced in volume. The inert solid plastic balls can not only avoid being corroded by the acid, but also enter the interface between the drill tool and the mud cake together with the pipe sticking releasing fluid, reducing the friction resistance and increasing the torque. The organic corrosion inhibitor molecule contains polar groups such as amino, hydroxyl, mercapto, etc., and plays a protective role by forming a coordination chelate film with metal surface ions. By soaking the stuck drill tool with the pipe sticking releasing working fluid prepared with acetic acid as the base acid, the mudstone chips are dissolved, so as to release the stuck drill tool, which is an organic weak acid type pipe sticking releasing working fluid.

[0029] The corrosion inhibitor is set to be one of quaternary ammonium salts, Mannich bases and imidazolines. The acid solution and the corrosion inhibitor are added to a conventional corrosion bottle, and the test pieces that have been pretreated and weighed are placed in a constant temperature water bath. After placing at the test temperature, the test pieces are taken out, cleaned, dried, weighed, and the corrosion rate is calculated. In the composite acid solution, the corrosion temperature is 90 °C, the corrosion time is 4 h, and under normal pressure conditions, only the concentrations of Mannich base and quaternary ammonium salt corrosion inhibitors are changed to investigate the influence of the dosage of the corrosion inhibitor on the corrosion rate of the test pieces;

[0030] The acetic acid is set to be one of calcium acetate, iron acetate and magnesium acetate. The main components in the clay fabric are Na + 、Ca 2+ , followed by K + 、Li + etc. The metal components in these clays provide a material basis for the effectiveness of the acid type pipe sticking releasing agent. The purpose of the bath acid is to dissolve the section where the drill tool contacts the wellbore wall, so as to achieve the purpose of releasing the stuck pipe. At present, the reaction speed of the mainstream hydrochloric acid solution used is very fast. When the acid solution consumes all the surface reactive components, the acid solution can no longer produce an effect, which creates an illusion of ineffective acid solution. Therefore, appropriately slowing down the reaction speed of the acid solution is the key factor for the successful release of the acid type pipe sticking releasing agent. In order to effectively control the reaction rate, organic acids are used instead of strong acids. Acetic acid is cheap and easy to obtain. Calcium acetate, iron acetate and magnesium acetate are all easily soluble in water and can be used as the main components of the pipe sticking releasing fluid. By reacting the acid solution with quartz, clay, calcareous substances, etc. in the rock, the blockage near the sticking point is dissolved or reduced in volume,

[0031] Al4[Si4O 10 (OH)8 + 48H + →4H2Si 6 +4H34l 6+ +18H2O.

[0032] Hydrofluoric acid is produced by reacting bromine water with potassium fluoride or ammonium hydride. The reaction equation is HBr + KF → HF + KBr.

[0033] The plastic balls are inert solids, which are prepared from polyethylene or polypropylene. The polyethylene and polypropylene materials are cut into small particles, and then the cut small particles are put into a special melting machine or melting furnace. The temperature and heating time are set to melt the small particles into a liquid state. Finally, at the outlet of the melting machine or above the melting liquid surface, the molten plastic liquid is dripped to form balls. The plastic balls can be well dispersed and suspended in the composite acid solution, which is more suitable. By using the inert solid plastic balls, it can not only avoid being corroded by acid, but also enter the interface between the drill tool and the mud cake together with the pipe un-sticking fluid, reduce the friction resistance and increase the torque.

[0034] Quaternary ammonium salts are products obtained by mixing a quaternization reagent with an alcohol solvent to react to form a mixture, and then purifying the mixture by filtration.

[0035] The quaternization reagent is set as one of methylammonium iodide, methylammonium bromide, trimethylsulfonium bromide and bromoalkane.

[0036] Mannich base is synthesized by reacting an amine, a ketone or an aldehyde nucleophile under alkaline conditions. The lone pair electrons of the coordinating atoms in the Mannich base enter the hybrid empty orbitals of Fe 3+ to form a coordination bond, undergo a complexation reaction, generate a stable cyclic chelate adsorbed on the metal surface, form a stable hydrophobic protective film, thereby preventing the diffusion of Fe 3+ produced by corrosion into the solution to achieve the purpose of metal corrosion inhibition. Mannich base corrosion inhibitors have attracted much attention as corrosion inhibitors suitable for concentrated hydrochloric acid media under high temperature conditions due to their good corrosion inhibition performance, and are the current research hotspots of corrosion inhibitors; Mannich base is a class of corrosion inhibitors with excellent performance and is widely used as a corrosion inhibitor for high temperature concentrated hydrochloric acid in acidizing operations. By introducing a heterocyclic ring and an aromatic ring containing lone pair electrons into the molecular structure, not only the adsorption ability of the coordinating atoms can be improved, but also π-bond adsorption can be formed on the metal surface to further improve its corrosion inhibition performance, and it is commonly used as the main agent of acidizing corrosion inhibitors.

[0037] Imidazoline is obtained by reacting an ethanolamine reagent and dimethylimidazole in a dry reaction chamber under nitrogen protection to obtain a reaction product, then purifying and crystallizing the reaction product to obtain crystalline particles, and finally drying the crystalline particles to obtain imidazoline.

[0038] Based on the above-described organic weak acid type pipe un-sticking working fluid, the present invention also provides a preparation method of an organic weak acid type pipe un-sticking working fluid, as Figure 1 shown, which includes the following steps:

[0039] S1. Place hydrochloric acid and hydrofluoric acid in a reaction vessel in proportion and mix them to obtain a mixture.

[0040] S2. Slowly add water to the mixture and stir it with a magnetic stirrer to obtain a mixed solution.

[0041] S3. Add an inhibitor and plastic balls to the mixed solution and continue stirring to obtain a reaction mixed solution.

[0042] S4. Add acetic acid to the reaction mixed solution to react and obtain a reaction mixture.

[0043] S5. Filter the reaction mixture to remove impurities and solid particles in the reaction mixture, and the obtained liquid is the pipe sticking working fluid.

[0044] Example 2

[0045] The same parts will not be repeated. Different from Example 1, by mass percentage, it includes the following raw materials: 6.5% hydrochloric acid, 8.5% hydrofluoric acid, 24% water, 1% inhibitor, 1.9% plastic balls, 58.2% acetic acid. Soak the stuck drill pipe with the pipe sticking working fluid prepared with acetic acid as the base acid to dissolve the mudstone chips.

[0046] Example 3

[0047] The same parts will not be repeated. Different from Example 1, by mass percentage, it includes the following raw materials: 5% hydrochloric acid, 7% hydrofluoric acid, 26% water, 0.9% inhibitor, 1.9% plastic balls, 59.2% acetic acid. The organic weak acid type pipe sticking working fluid prepared with the above raw materials has strong applicability, high performance, economic environmental protection, reliable construction and high pipe sticking release success rate.

[0048] Example 4

[0049] Use an adhesion coefficient measuring instrument to evaluate the pipe sticking release ability of different pipe sticking release fluids, record the time required for pipe sticking release, and take the average value of three times as the basis to evaluate the pipe sticking release effect of various pipe sticking release fluids.

[0050] Serial number Organic weak acid pipe release fluid Environmentally friendly oil pipe release fluid Water-based inorganic salt pipe release fluid 1 15min 110min 80min 2 20min 105min 85min 3 15min 115min 90min Average 17min 110min 85min

[0051] Experiments show that the pipe sticking release time: organic weak acid pipe sticking release fluid < water-based inorganic salt < environmental protection oil.

[0052] Use the organic weak acid type pipe sticking working fluid provided by the present invention for actual application, and the application cases are as follows:

[0053] For the pipe sticking accidents in Well Saf 955-Ping 3 and Well Puf 208-Ping 3, when the grease type pipe sticking release agent and other pipe sticking release means are ineffective, use the organic weak acid pipe sticking working fluid to successfully release the pipe sticking accidents in the two wells. The test statistical results are as follows:

[0054]

[0055] It can be obtained from the tabular data that the pipe sticking release working fluid of the organic weak acid type provided by the present invention has a remarkable pipe sticking release effect, and the downhole rotary steerable instrument is not damaged. Through field application, the construction is reliable, and the pipe sticking release success rate is high. It is a relatively reliable, applicable, efficient and economical means to solve the pipe sticking accident caused by mudstone spalling at present.

[0056] In summary, the pipe sticking release working fluid of the organic weak acid type prepared from hydrochloric acid, hydrofluoric acid, water, corrosion inhibitor, plastic balls and acetic acid, and the pipe sticking release working fluid prepared with acetic acid as the base acid is used to soak the stuck drill pipe, achieving the dissolution of mudstone spalling. It has a unique and reasonable concept, strong applicability, high performance, economic and environmental protection, reliable construction, and a high pipe sticking release success rate.

[0057] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. Organic weak acid type pipe sticking release working fluid, characterized in that: By mass percentage, it includes the following raw materials: 5%-7% hydrochloric acid, 7%-9% hydrofluoric acid, 24%-26% water, 0.9%-1.1% corrosion inhibitor, 1.9%-2.1% plastic balls, and 57.5%-59.5% acetic acid. The corrosion inhibitor is set as one of quaternary ammonium salts, Mannich bases, and imidazolines.

2. The organic weak acid type pipe sticking release working fluid according to claim 1, characterized in that: By mass percentage, it includes the following raw materials: 6% hydrochloric acid, 8% hydrofluoric acid, 25% water, 1% corrosion inhibitor, 2% plastic balls, and 58% acetic acid.

3. The organic weak acid type pipe sticking release working fluid according to claim 1, characterized in that: The acetic acid is set as one of calcium acetate, iron acetate, and magnesium acetate.

4. The organic weak acid type pipe sticking release working fluid according to claim 2, characterized in that: The hydrofluoric acid is generated by reacting bromine water with potassium fluoride or ammonium hydride to produce hydrofluoric acid. The reaction equation is HBr + KF → HF + KBr.

5. The organic weak acid type pipe sticking release working fluid according to claim 1, characterized in that: The plastic balls are inert solids. The plastic balls are prepared from polyethylene or polypropylene. The polyethylene and polypropylene materials are cut into small particles, and then the cut small particles are put into a special melting machine or melting furnace. The temperature and heating time are set to melt the small particles into a liquid state. Finally, at the outlet of the melting machine or above the melting liquid surface, the molten plastic liquid is dropped to form balls.

6. The organic weak acid type pipe sticking release working fluid according to claim 5, characterized in that: The quaternary ammonium salt is a product obtained by mixing a quaternarization reagent with an alcohol solvent and reacting to form a mixture, and then purifying the mixture by filtration.

7. The organic weak acid type pipe sticking release working fluid according to claim 6, characterized in that: The quaternarization reagent is set as one of methylammonium iodide, methylammonium bromide, trimethylsulfonium bromide, and bromoalkanes.

8. The organic weak acid type pipe sticking release working fluid according to claim 1, characterized in that: The Mannich base is synthesized by reacting an amine, a ketone or an aldehyde nucleophile under alkaline conditions. The lone pair electrons of the coordinating atoms in the Mannich base enter the hybridized empty orbitals of Fe 3+ to form a coordination bond, and a complexation reaction occurs to generate a stable cyclic chelate that adsorbs on the metal surface, forming a stable hydrophobic protective film, thereby preventing the diffusion of Fe 3+ produced by corrosion into the solution to achieve the purpose of metal corrosion inhibition.

9. The organic weak acid type pipe sticking release working fluid according to claim 1, characterized in that: The imidazoline is obtained by reacting ethanolamine reagent and dimethylimidazole in a dry reaction chamber under nitrogen protection to obtain a reaction product, then purifying and crystallizing the reaction product to obtain crystalline particles, and finally drying the crystalline particles to obtain imidazoline.

10. A preparation method of an organic weak acid type pipe sticking release working fluid, based on the organic weak acid type pipe sticking release working fluid according to any one of claims 1-9, characterized in that: It includes the following steps: S1. Place hydrochloric acid and hydrofluoric acid in a reaction vessel in proportion and mix them to react to obtain a mixture. S2. Slowly add water to the mixture and stir it with a magnetic stirrer to obtain a mixed solution. S3. Add a corrosion inhibitor and plastic balls to the mixed solution and continue to stir to obtain a reaction mixed solution. S4. Add acetic acid to the reaction mixed solution to react to obtain a reaction mixture. S5. Filter the reaction mixture to remove impurities and solid particles in the reaction mixture, and the obtained liquid is the pipe sticking release working fluid.

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