Preparation method of pentaerythritol and application thereof

Abstract

This invention provides a method for preparing pentaerythritol and its applications. The method includes the following steps: obtaining a pentaerythritol precursor from pentaerythritol tetrachloride via the Gabriel synthesis method. This method improves the yield of pentaerythritol and significantly simplifies the synthetic route. Furthermore, it can be applied to the preparation of MOF derivative-pentaerythritol type blocking-inhibitors, and the resulting MOF derivative-pentaerythritol type blocking-inhibitors exhibit good inhibitory performance and compatibility.

Description

Technical Field

[0001] This invention belongs to the field of drilling fluid reagent technology for petroleum drilling, specifically relating to a method for preparing and applying a MOF derivative inhibitor monomer, pentaerythritol. Background Technology

[0002] Wellbore instability is a common phenomenon during drilling. If not handled properly, it can lead to incalculable losses of manpower, financial resources, and time, and may cause accidents such as well collapse, stuck drill bit, blowout, or even wellbore abandonment, seriously affecting the development of oil and gas resources.

[0003] As exploration and development expands into deep, ultra-deep, unconventional, and green / clean areas, the use of efficient treatment agents to stabilize clay minerals in formations is essential for the smooth and effective operation of oil extraction during field operations. Currently, inorganic salt-based shale inhibitors, bituminous inhibitors, and polyol-based shale inhibitors are among the most mature and stable inhibitors in oilfield operations. However, these inhibitors all have various shortcomings and complex limitations. For example, inorganic salt inhibitors have unsatisfactory performance, bituminous inhibitors' fluorescence properties do not meet environmental protection requirements, and polyethylene glycol inhibitors perform poorly in addressing drilling problems involving reactive shale.

[0004] Therefore, with the increasing understanding and implementation of the concepts of green, clean, and sustainable energy development, and the increasing volume of deep and ultra-deep well drilling, amine-based treatment agents are becoming increasingly popular. Currently, amine inhibitors have become the most commonly used inhibitors in the petrochemical field. Compared with other types of inhibitors, amine inhibitors have many advantages. For example, their toxicity is lower than that of polymer inhibitors and asphalt inhibitors, resulting in less environmental pollution and less harm to human health during oilfield operations. Furthermore, compared to inorganic cationic and low-molecular-weight cationic polymer inhibitors, amine inhibitors have strong adaptability and high compatibility, which is beneficial for the exploitation of deep and ultra-deep wells and for reducing the economic and labor costs of on-site petrochemical applications. Aliphatic diamines and polyamines are a class of amine inhibitors, which can be further divided into linear and branched structures based on their molecular structure. Linear aliphatic diamines and polyamines have some effect, but it is difficult to balance the inhibitory and rheological properties of water-based drilling fluids. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a method for preparing pentaerythritol, which effectively improves the yield of pentaerythritol and significantly simplifies the synthetic route.

[0006] To achieve the above objectives, the present invention provides a method for preparing pentaerythritol tetramine, comprising the following steps:

[0007] The pentaerythritol tetrachloride precursor was obtained by the Gabriel synthesis method.

[0008] According to a specific embodiment of the present invention, preferably, in the above preparation method, the pentaerythritol tetrachloride can be obtained by the following steps:

[0009] Pentaerythritol was used as a raw material to generate pentaerythritol tetrachloride in the presence of thionyl chloride and a first catalyst.

[0010] According to a specific embodiment of the present invention, preferably, in the above preparation method, the pentaerythritol precursor is further hydrolyzed to obtain pentaerythritol.

[0011] According to a specific embodiment of the present invention, preferably, in the process of preparing pentaerythritol, thionyl chloride and a first catalyst are added dropwise to pentaerythritol, and the mixture is refluxed at 65°C-95°C for 4-7.5 hours, and then the solvent is removed to obtain pentaerythritol.

[0012] According to a specific embodiment of the present invention, preferably, in the process of preparing the pentaerythritol tetramine precursor, potassium phthalimide and pentaerythritol tetrachloride are dissolved in N,N-dimethylformamide, the reaction is controlled to be anhydrous, and the reaction is carried out at 85℃-115℃ for 45 min-2 h to obtain the pentaerythritol tetramine precursor.

[0013] According to a specific embodiment of the present invention, preferably, during the hydrolysis of the pentaerythritol precursor, the pentaerythritol precursor, ethanol and hydrazine hydrate are mixed, refluxed for 1-2 hours, filtered to obtain a filtrate, and the filtrate is adjusted to alkaline and extracted to obtain pentaerythritol.

[0014] According to a specific embodiment of the present invention, preferably, in the above-described preparation of pentaerythritol tetrachloride, the first catalyst is N,N-dimethylformamide.

[0015] According to a specific embodiment of the present invention, preferably, in the above-mentioned preparation of pentaerythritol tetrachloride, the molar ratio of pentaerythritol to thionyl chloride is 1:20-28.

[0016] According to a specific embodiment of the present invention, preferably, the reaction temperature is 70°C during the above-mentioned preparation of pentaerythritol tetrachloride.

[0017] According to a specific embodiment of the present invention, preferably, the reaction time in the above-mentioned preparation of pentaerythritol tetrachloride is 5 hours.

[0018] According to a specific embodiment of the present invention, preferably, in the process of preparing the pentaerythritol precursor, the method for preparing potassium phthalimide is as follows: reacting an ethanol solution of phthalimide with a methanol solution of potassium hydroxide at room temperature for 3-5 hours, and then filtering to obtain potassium phthalimide.

[0019] According to a specific embodiment of the present invention, preferably, in the above-mentioned method for preparing potassium phthalimide, the molar ratio of phthalimide to potassium hydroxide is 1:1.

[0020] According to a specific embodiment of the present invention, preferably, in the process of preparing the pentaerythritol tetrachloride precursor, the molar ratio of pentaerythritol tetrachloride to potassium phthalimide is 1:3-8, preferably 1:4.

[0021] According to a specific embodiment of the present invention, preferably, the reaction time in the above-mentioned preparation of pentaerythritol precursor is 1 hour.

[0022] According to a specific embodiment of the present invention, preferably, during the hydrolysis of the above-mentioned pentaerythritol precursor, the pH of the filtrate is adjusted to 7-10.

[0023] According to a specific embodiment of the present invention, preferably, the reflux temperature is 90°C during the hydrolysis of the above-mentioned pentaerythritol precursor.

[0024] According to a specific embodiment of the present invention, preferably, the reflux time is 1 hour during the hydrolysis of the above-mentioned pentaerythritol precursor.

[0025] The present invention also provides the application of the above preparation method in the preparation of drilling fluid inhibitors.

[0026] According to a specific embodiment of the present invention, preferably, in the above application, the drilling fluid inhibitor is a MOF derivative-pentaerythritol type plugging-inhibitor.

[0027] According to a specific embodiment of the present invention, preferably, in the above application, the preparation method of the MOF derivative-pentaerythritol type blocking-inhibitor includes the following steps:

[0028] Pentaerythritol, 2-methylimidazole and a second catalyst are mixed in a reaction solvent to obtain a MOF derivative-pentaerythritol type blocking-inhibitor. The molar ratio of pentaerythritol, 2-methylimidazole and the second catalyst is 1-5:10-20:5-13, more preferably 2-4:13-18:6-10.

[0029] According to a specific embodiment of the present invention, preferably, in the above-mentioned method for preparing MOF derivative-pentaerythritol-type blocking-inhibitor, the second catalyst is one or a combination of two or more of zinc nitrate hexahydrate, cobalt nitrate hexahydrate, zinc hexafluorosilicate hexahydrate, aluminum nitrate hydrate, and yttrium nitrate hexahydrate, and the reaction solvent is one or a combination of two or more of methanol, ethanol, and isopropanol.

[0030] According to a specific embodiment of the present invention, pentaerythritol is prepared by the following specific steps:

[0031] (1) Preparation of pentaerythritol tetrachloride (S1-S6)

[0032] Step S1: Construct a condensation reflux experimental apparatus with a drying tube;

[0033] Step S2: Add pentaerythritol to the three-necked flask. Except for the drying tube which is connected to the outside, all other outlets are sealed with rubber stoppers.

[0034] Step S3: Turn on the magnetic stirrer and slowly rotate the magnetic wand to slowly add thionyl chloride dropwise to pentaerythritol using a constant pressure dropping funnel;

[0035] Step S4: After adding DMF as a catalyst, slowly raise the temperature to about 70°C;

[0036] Step S5: Observe the reaction phenomenon, and continue reflux for about 5 hours after the solid has completely dissolved;

[0037] Step S6: After the reaction is complete, the reaction product is subjected to rotary evaporation under reduced pressure. During rotary evaporation, dichloromethane can be added to the rotary evaporation flask multiple times to carry the solvent until the product is dried to obtain pentaerythritol tetrachloride.

[0038] (2) Preparation of pentaerythritol precursor (S7-S14)

[0039] Step S7: Dissolve phthalimide in ethanol, then slowly add a methanol solution of KOH to the solution;

[0040] Step S8: The molar ratio of substances is fixed at n(phthalimide):n(potassium hydroxide) = 1:1, the reaction temperature is room temperature, and the reaction time is 3 hours.

[0041] Step S9: After the reaction is complete, the mixture is filtered and the resulting filtrate is washed with ethanol to obtain potassium phthalimide.

[0042] Step S10: Prepare pentaerythritol precursor. This process is strictly controlled to be anhydrous, and all instruments are dried in advance.

[0043] Step S11: Set up the reaction apparatus and add potassium phthalimide and an appropriate amount of DMF to the three-necked flask;

[0044] Step S12: Add pentaerythritol tetrachloride and slowly heat to 90°C to carry out the reaction. Stop the reaction after 45 minutes.

[0045] Step S13: Mix the mixture of chloroform and water with the reaction solution after the reaction is complete, and then separate the liquids.

[0046] Step S14: After separation, the organic phase is dried with anhydrous sodium sulfate, filtered, and then rotary evaporated under reduced pressure to obtain the pentaerythritol precursor.

[0047] (3) Hydrolysis of pentaerythritol precursor (S15-S18):

[0048] Step S15: Set up the stirring device, condenser reflux device, etc.;

[0049] Step S16: After thoroughly mixing the synthesized pentaerythritol precursor with an appropriate amount of ethanol and hydrazine hydrate, pour the mixture into a three-necked flask.

[0050] Step S17: Turn on the stirring device and raise the temperature to a certain level, while observing the condensation and reflux phenomenon and reacting for a period of time;

[0051] Step S18: After the reaction is complete, the hydrolyzed product is cooled and filtered under reduced pressure. Then, the pH of the filtrate is adjusted to alkaline and extracted to obtain the product pentaerythritol.

[0052] Beneficial effects:

[0053] (1) The present invention uses the Gabriel method to construct a synthetic route for synthesizing a monomeric pentaerythritol that constitutes a hyperbranched structure, which effectively improves the product yield and greatly simplifies the synthetic route, thus demonstrating good economic value. At the same time, the obtained pentaerythritol also has a special dendritic structure, which has a higher density of amino groups compared with the three most common aliphatic diamines and polyamines.

[0054] (2) Due to its special structural features and high density of amino groups, the branched pentaerythritol can increase the water solubility of the inhibitor and adhere to the adjacent clay crystal layer, thus playing a pulling effect and making the adsorption of the inhibitor stronger, thereby making the clay crystal layer more solid. This solves the problem of wellbore instability during drilling, effectively avoids the occurrence of wellbore instability, clay hydration and other problems, improves the overall inhibitory properties and compatibility of drilling fluid, and provides technical support for the exploration and development of oil and gas resources.

[0055] (3) As exploration and development expand into deep, ultra-deep, unconventional, and green / clean fields, drilling engineering faces increasingly demanding geological conditions, leading to a growing need for new high-energy-density materials and dendritic macromolecular monomers. This invention can efficiently support oil and gas resource exploration and development, and comprehensively improve the capacity and level of green, clean, and efficient energy. Detailed Implementation

[0056] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0057] Example 1

[0058] This embodiment provides a hyperbranched monomeric small molecule pentaerythritol, suitable for use as a drilling fluid inhibitor, which is prepared by the following method:

[0059] A reflux condensation apparatus with a drying tube was constructed. 0.01 mol of pentaerythritol was added to a three-necked flask. Except for the drying tube, which was connected to the outside, all other outlets were sealed with rubber stoppers. A magnetic stirrer was turned on and the magnetic stir bar was slowly rotated. 0.20 mol of thionyl chloride was slowly added dropwise to pentaerythritol using a constant pressure dropping funnel. Finally, DMF was added as a catalyst. After the addition was complete, the temperature was slowly raised to about 65°C, and the reaction was observed. After the solid was completely dissolved, reflux was continued for about 4.5 hours. After the reaction was completed, rotary evaporation under reduced pressure was performed until the solid was dried to obtain pentaerythritol tetrachloride.

[0060] An anhydrous reaction apparatus was set up. 0.04 mol of potassium phthalimide and an appropriate amount of DMF were added to a three-necked flask, followed by 0.01 mol of pentaerythritol tetrachloride. The temperature was slowly raised to 85°C for the reaction, which was stopped after 45 minutes. The reactants were then mixed with a mixture of chloroform and water and separated. After separation, the organic phase was dried with anhydrous sodium sulfate, filtered, and subjected to rotary evaporation under reduced pressure to obtain the pentaerythritol tetrachloride precursor. The pentaerythritol tetrachloride precursor was refluxed in an alcoholic solution of hydrazine for 2 hours or left at room temperature for 1-2 days. After the reaction was complete, the mixture was filtered under reduced pressure. The pH of the mother liquor was adjusted to alkaline, and the solvent was removed by extraction to obtain a gray-black solid product, which was pentaerythritol tetrachloride. The yield was tested to be 65%.

[0061] Example 2

[0062] This embodiment provides a hyperbranched monomeric small molecule pentaerythritol, suitable for use as a drilling fluid inhibitor, which is prepared by the following method:

[0063] A reflux condensation apparatus with a drying tube was constructed. 0.01 mol of pentaerythritol was added to a three-necked flask. Except for the drying tube, which was connected to the outside, all other outlets were sealed with rubber stoppers. A magnetic stirrer was turned on and the magnetic stir bar was rotated slowly. 0.20 mol of thionyl chloride was slowly added dropwise to pentaerythritol using a constant pressure dropping funnel. Finally, DMF was added as a catalyst. After the addition was complete, the temperature was slowly raised to about 70°C, and the reaction was observed. After the solid was completely dissolved, reflux was continued for about 5 hours. After the reaction was completed, rotary evaporation under reduced pressure was performed until the solid was dried to obtain pentaerythritol tetrachloride.

[0064] An anhydrous reaction apparatus was set up. 0.04 mol of potassium phthalimide and an appropriate amount of DMF were added to a three-necked flask, followed by 0.01 mol of pentaerythritol tetrachloride. The temperature was slowly raised to 85°C for the reaction, which was stopped after 45 min. The reactants were then mixed with a mixture of chloroform and water and separated. After separation, the organic phase was dried with anhydrous sodium sulfate, filtered, and subjected to rotary evaporation under reduced pressure to obtain the pentaerythritol tetrachloride precursor. The pentaerythritol tetrachloride precursor was refluxed in an alcoholic solution of hydrazine for 2 hours or left at room temperature for 1-2 days. After the reaction was complete, the mixture was filtered under reduced pressure. The pH of the mother liquor was adjusted to alkaline, and the solvent was removed by extraction to obtain a gray-black solid product, which was pentaerythritol tetrachloride. The yield was tested to be 75%.

[0065] Example 3

[0066] This embodiment provides a hyperbranched monomeric small molecule pentaerythritol, suitable for use as a drilling fluid inhibitor, which is prepared by the following method:

[0067] A reflux condensation apparatus with a drying tube was constructed. 0.01 mol of pentaerythritol was added to a three-necked flask. Except for the drying tube, which was connected to the outside, all other outlets were sealed with rubber stoppers. A magnetic stirrer was turned on and the magnetic stir bar was slowly rotated. 0.20 mol of thionyl chloride was slowly added dropwise to pentaerythritol using a constant pressure dropping funnel. Finally, DMF was added as a catalyst. After the addition was complete, the temperature was slowly raised to about 75°C, and the reaction was observed. After the solid was completely dissolved, reflux was continued for about 5 hours. After the reaction was completed, rotary evaporation under reduced pressure was performed until the solid was dried to obtain pentaerythritol tetrachloride.

[0068] An anhydrous reaction apparatus was set up. 0.04 mol of potassium phthalimide and an appropriate amount of DMF were added to a three-necked flask, followed by 0.01 mol of pentaerythritol tetrachloride. The temperature was slowly raised to 90°C for the reaction, which was stopped after 1 hour. The reactants were then mixed with a mixture of chloroform and water and separated. After separation, the organic phase was dried with anhydrous sodium sulfate, filtered, and subjected to rotary evaporation under reduced pressure to obtain the pentaerythritol tetrachloride precursor. The pentaerythritol tetrachloride precursor was refluxed in an alcoholic solution of hydrazine for 2 hours or left at room temperature for 1-2 days. After the reaction was complete, the mixture was filtered under reduced pressure. The pH of the mother liquor was adjusted to alkaline, and the solvent was removed by extraction to obtain a gray-black solid product, which was pentaerythritol tetrachloride. The yield was tested to be 80%.

[0069] Example 4

[0070] This embodiment provides a hyperbranched monomeric small molecule pentaerythritol, suitable for use as a drilling fluid inhibitor, which is prepared by the following method:

[0071] A reflux condensation apparatus with a drying tube was constructed. 0.01 mol of pentaerythritol was added to a three-necked flask. Except for the drying tube, which was connected to the outside, all other outlets were sealed with rubber stoppers. A magnetic stirrer was turned on and the magnetic stir bar was slowly rotated. 0.20 mol of thionyl chloride was slowly added dropwise to pentaerythritol using a constant pressure dropping funnel. Finally, DMF was added as a catalyst. After the addition was complete, the temperature was slowly raised to about 75°C, and the reaction was observed. After the solid was completely dissolved, reflux was continued for about 5 hours. After the reaction was completed, rotary evaporation under reduced pressure was performed until the solid was dried to obtain pentaerythritol tetrachloride.

[0072] An anhydrous reaction apparatus was set up. 0.04 mol of potassium phthalimide and an appropriate amount of DMF were added to a three-necked flask, followed by 0.01 mol of pentaerythritol tetrachloride. The temperature was slowly raised to 95°C for the reaction, which was stopped after 1 hour. The reactants were then mixed with a mixture of chloroform and water and separated. After separation, the organic phase was dried with anhydrous sodium sulfate, filtered, and subjected to rotary evaporation under reduced pressure to obtain the pentaerythritol tetrachloride precursor. After the reaction, the pentaerythritol tetrachloride precursor was refluxed in an alcoholic solution of hydrazine for 2 hours or left at room temperature for 1-2 days, followed by vacuum filtration. The pH of the mother liquor was adjusted to alkaline, and after extraction and solvent removal, a gray-black solid product was obtained, which was the product pentaerythritol tetrachloride. The yield was tested to be 80%.

[0073] Example 5

[0074] This embodiment provides a hyperbranched monomeric small molecule pentaerythritol, suitable for use as a drilling fluid inhibitor, which is prepared by the following method:

[0075] A reflux condensation apparatus with a drying tube was constructed. 0.01 mol of pentaerythritol was added to a three-necked flask. Except for the drying tube, which was connected to the outside, all other outlets were sealed with rubber stoppers. A magnetic stirrer was turned on and the magnetic stir bar was rotated slowly. 0.20 mol of thionyl chloride was slowly added dropwise to pentaerythritol using a constant pressure dropping funnel. Finally, DMF was added as a catalyst. After the addition was complete, the temperature was slowly raised to about 70°C, and the reaction was observed. After the solid was completely dissolved, reflux was continued for about 5 hours. After the reaction was completed, rotary evaporation under reduced pressure was performed until the solid was dried to obtain pentaerythritol tetrachloride.

[0076] An anhydrous reaction apparatus was set up. 0.04 mol of potassium phthalimide and an appropriate amount of DMF were added to a three-necked flask, followed by 0.01 mol of pentaerythritol tetrachloride. The temperature was slowly raised to 90°C for the reaction, which was stopped after 1 hour. The reactants were then mixed with a mixture of chloroform and water and separated. After separation, the organic phase was dried with anhydrous sodium sulfate, filtered, and subjected to rotary evaporation under reduced pressure to obtain the pentaerythritol tetrachloride precursor. The pentaerythritol tetrachloride precursor was refluxed in an alcoholic solution of hydrazine for 2 hours or left at room temperature for 1-2 days. After the reaction was complete, the mixture was filtered under reduced pressure. The pH of the mother liquor was adjusted to alkaline, and the solvent was removed by extraction to obtain a gray-black solid product, which was pentaerythritol tetrachloride. The yield was tested to be 90%.

[0077] Test Example 1

[0078] In this test example, the small molecule monomer pentaerythritol, which constitutes a hyperbranched structure, provided in Example 5, was thoroughly mixed with 2-methylimidazole and zinc nitrate hexahydrate in a molar ratio of 2-4:13-18:6-10 in a methanol solution to prepare a MOF derivative-pentaerythritol organic-inorganic hybrid material. After purification, the MOF derivative-pentaerythritol type blocking-inhibitor was obtained.

[0079] Blank sample: 6% sodium bentonite-based slurry;

[0080] Test Sample 1: The MOF derivative-pentaerythritol type blocking-inhibitor prepared by pentaerythritol provided in Example 5 of this invention was added to the blank sample to obtain Test Sample 1. The specific composition and blocking performance results are shown in Table 1.

[0081] The sealing performance here is mainly evaluated by the amount of filtration loss, which is measured by a medium-pressure filtration loss meter in mL. The filtration loss is measured at 30s, 5min, 10min, 15min, 25min and 30min.

[0082] Table 1. Plugging performance of MOF derivative-pentaerythritol type plugging-inhibitor

[0083]

[0084] As shown in Table 1, the synthesized MOF derivative-pentaerythritol-type plugging-inhibitor effectively reduced the filtrate loss of the substrate slurry, exhibiting excellent plugging performance. The total filtrate loss of the prepared MOF derivative-pentaerythritol-type plugging-inhibitor within 30 min was only 4.4 mL, representing a maximum reduction of 18.3%. The MOF derivative-pentaerythritol-type plugging-inhibitor mentioned below (such as Test Example 2) refers to the MOF derivative-pentaerythritol-type plugging-inhibitor of Test Example 1.

[0085] Test Example 2

[0086] Three typical drilling fluid systems were selected, and their specific compositions are as follows:

[0087] ① 2% sodium bentonite + 0.3% NaOH + 7% KCl + 3% anti-thermal emulsion polymer plugging agent + 6% filtration loss reducer SMP-3 + 6% viscosity reducer SMC + 4% plugging agent FT-1 + 2% viscosity reducer SMT + 4% ultrafine calcium carbonate + 1% lubricant DR-1;

[0088] ② 2% Sodium Bentonite + 0.3% NaOH + 7% KCl + 1% Filtration Loss Reducer PAC-LV + 8% Filtration Loss Reducer SMP-3 + 3% Blocking Agent FT-1 + 1% Organic Amine Inhibitor AP-1 + 1% Nanoemulsion Blocking Agent + 4% Ultrafine Calcium Carbonate + 0.5% Emulsifier OP-10 + 4% Lubricant HY-202;

[0089] ③ 2% sodium bentonite + 0.2% NaOH + 7% KCl + 1% filtration loss reducer PAC-LV + 5% filtration loss reducer SMP-3 + 1% polyamine inhibitor NH-1 + 0.3% coating agent KH-PAM + 4% nano-blocking agent NP-1 + 5.0% polyol + 2% lubricant HY-202;

[0090] All samples were weighted to 2.0 g / mL using barite.

[0091] The original plugging agent and organic inhibitor in the drilling fluid were replaced with 3% MOF derivative-pentaerythritol type plugging-inhibitor. The rheological and filtration properties of the three drilling fluids before and after replacement, and the rolling recovery rate of mudstone in the drilling fluid were determined according to the national standard GB / T 6783-2014 "Field Test Procedure for Water-based Drilling Fluids". The results are shown in Tables 2 and 3.

[0092] The original plugging agent and organic inhibitor in the drilling fluid were replaced with 3% MOF derivative-pentaerythritol type plugging-inhibitor, and the rheological properties of the fluid before and after aging (aging conditions: 150℃×16h) were measured using a six-speed viscometer.

[0093] "PV" refers to plastic viscosity, which is measured by a Pantheon six-speed viscometer and is measured in mPa·s.

[0094] PV = θ 600 -θ 300

[0095] "AV" refers to apparent viscosity, measured by a Pantheon six-speed viscometer, and the unit is mPa·s;

[0096]

[0097] “YP” refers to dynamic shear force, which is calculated from data measured by a Pantheon six-speed viscometer, and the unit is Pa.

[0098] YP = 0.511(θ) 300 -PV)

[0099] “G10” / G10’” refers to the gel strength initial shear / final shear, calculated from data measured by a Pantheon six-speed viscometer, and the unit is Pa;

[0100] Initial tangent = 0.511θ³(10s)

[0101] Final tangent = 0.511θ3 (10 min)

[0102] "API" refers to medium-pressure filtration loss, which is measured by a medium-pressure filtration loss meter and is measured in mL.

[0103] "HTHP" refers to high temperature and high pressure filtration loss, which is measured by a high temperature and high pressure filtration loss meter and is measured in mL.

[0104] The results are shown in Table 2.

[0105] Table 2. Effects of MOF derivative-pentaerythritol-type plugging-inhibitors on drilling fluid properties

[0106]

[0107]

[0108] As shown in Table 2, the experimental results of the effect of MOF derivative-pentaerythritol plugging-inhibitor on drilling fluid performance indicate that after replacing the original plugging agent and organic inhibitor with 3% MOF derivative-pentaerythritol plugging-inhibitor in all three drilling fluid systems, the rheological properties of the drilling fluid system before aging did not change significantly compared with those before replacement.

[0109] Table 3. Effects of MOF derivative-pentaerythritol-type plugging-inhibitors on drilling fluid rheological properties

[0110]

[0111] Table 3 shows that after aging at 150℃ for 16 hours, the rheological properties of the drilling fluid replaced by the plugging-inhibitor remained similar to those before replacement. API filtration loss also remained stable, with only a slight increase in HTHP filtration loss. The largest increase was observed in drilling fluid system ③, where HTHP filtration loss increased from 7.2 mL to 8.4 mL. The rolling recovery rate of shale in the replaced drilling fluid was superior to that of the original drilling fluid. The MOF derivative plugging-inhibitor dosage was only 3%, while the dosages of the original plugging agent and organic inhibitor in the replaced drilling fluid both exceeded 3%. These results indicate that the MOF derivative-pentaerythritol type plugging-inhibitor has no adverse effect on the rheological properties of the drilling fluid, and its inhibitory efficacy is outstanding. Even if its plugging performance is slightly weaker, it is expected that effective control of filtration loss can be achieved by appropriately adjusting its dosage and the ratio with other treatment agents. The compatibility test results of MOF derivative-pentaerythritol plugging-inhibitor with three drilling fluid systems show that it has good compatibility with different drilling fluid systems.

Claims

1. A method for preparing a MOF derivative-pentaerythritol-type blocking-inhibitor, comprising the following steps: Pentaerythritol, 2-methylimidazole, and a second catalyst are mixed in a reaction solvent to obtain a MOF derivative-pentaerythritol-type blocking-inhibitor. The molar ratio of pentaerythritol, 2-methylimidazole, and the second catalyst is 1-5 : 10-20 : 5-13. The second catalyst is one or a combination of two or more of zinc nitrate hexahydrate, cobalt nitrate hexahydrate, zinc hexafluorosilicate hexahydrate, aluminum nitrate hydrate, and yttrium nitrate hexahydrate. The reaction solvent is one or a combination of two or more of methanol, ethanol, and isopropanol.

2. The production method according to claim 1, wherein, The preparation method of the pentaerythritol tetramine includes the following steps: Potassium phthalimide and pentaerythritol tetrachloride were dissolved in N,N-dimethylformamide, and the reaction was carried out at 85℃-115℃ for 45 min-2 h to obtain the pentaerythritol tetraamine precursor.

3. The production method according to claim 2, wherein, The pentaerythritol tetrachloride is prepared by the following steps: Pentaerythritol was used as a raw material to generate pentaerythritol tetrachloride in the presence of thionyl chloride and a first catalyst. The first catalyst is N,N-dimethylformamide.

4. The production method according to claim 2, wherein, The pentaerythritol precursor was further hydrolyzed to obtain pentaerythritol.

5. The preparation method according to claim 3, wherein, Add thionyl chloride and a first catalyst dropwise to pentaerythritol, reflux at 65℃-95℃ for 4-7.5 hours, and then remove the solvent to obtain pentaerythritol tetrachloride.

6. The preparation method according to claim 4, wherein, The pentaerythritol precursor, ethanol, and hydrazine hydrate were mixed and refluxed for 1-2 hours. The mixture was then filtered to obtain a filtrate, which was adjusted to alkaline conditions and extracted to obtain pentaerythritol.

7. The preparation method according to claim 5, wherein, The molar ratio of pentaerythritol to thionyl chloride is 1:20-28.

8. The preparation method according to claim 2, wherein, The method for preparing potassium phthalimide is as follows: ethanol solution of phthalimide and methanol solution of potassium hydroxide are reacted at room temperature for 3-5 hours, and then filtered to obtain potassium phthalimide.

9. The preparation method according to claim 8, wherein, The molar ratio of phthalimide to potassium hydroxide is 1:

1.

10. The preparation method according to claim 2, wherein, The molar ratio of pentaerythritol tetrachloride to potassium phthalimide is 1:3-8.

11. The preparation method according to claim 6, wherein, Adjusting the filtrate to alkaline means adjusting the pH of the filtrate to 7-10.

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