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CN-121990776-A - Well cementing cement slurry, high-temperature-resistant modified poly-p-phenylene terephthamide fiber toughening agent for well cementing and preparation method thereof

CN121990776ACN 121990776 ACN121990776 ACN 121990776ACN-121990776-A

Abstract

The invention belongs to the technical field of petroleum and natural gas exploration and development, and particularly discloses a high-temperature-resistant modified poly-p-phenylene terephthalamide fiber toughening agent for well cementation and a preparation method thereof, wherein the high-temperature-resistant modified poly-p-phenylene terephthalamide fiber toughening agent for well cementation comprises, by weight, 1-5 parts of p-phenylene diamine, 5-10 parts of terephthaloyl chloride, 5-30 parts of calcium chloride, 5-30 parts of N-methylpyrrolidone and 80-100 parts of deionized water, and the high-temperature-resistant modified poly-p-phenylene terephthalamide fiber toughening agent for well cementation comprises, by weight, 1-3 parts of cement 100 parts, 35-45 parts of quartz sand, 2-4 parts of high-temperature-resistant fading agent, 1-3 parts of retarder, 2-4 parts of suspension stabilizer, 2-4 parts of filtrate reducer and 44-48 parts of clear water. The invention obviously improves the mechanical property of the cement stone at the temperature of more than 180 ℃, particularly enhances the toughness and plasticity of the cement stone, and obviously reduces the elastic modulus of the cement stone, thereby achieving the purpose of enhancing the toughness of the cement stone.

Inventors

  • ZHENG YOUZHI
  • ZHAO JUN
  • HE LANG
  • SANG YU
  • Jing Xingsheng
  • ZHANG ZHANWU
  • HE YU

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241105

Claims (14)

  1. 1. The high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughening agent for well cementation is characterized by comprising, by weight, 1-5 parts of p-phenylene terephthalamide, 5-10 parts of terephthaloyl chloride, 5-30 parts of calcium chloride, 5-30 parts of N-methylpyrrolidone and 80-100 parts of deionized water.
  2. 2. The high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughening agent for well cementation, which is characterized by comprising the following raw materials, by weight, 5 parts of p-phenylene diamine, 5 parts of terephthaloyl chloride, 10 parts of calcium chloride, 10 parts of N-methylpyrrolidone and 100 parts of deionized water.
  3. 3. The high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughening agent for well cementation, which is characterized by comprising the following raw materials, by weight, 5 parts of p-phenylene diamine, 5 parts of terephthaloyl chloride, 20 parts of calcium chloride, 20 parts of N-methylpyrrolidone and 100 parts of deionized water.
  4. 4. The high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughening agent for well cementation, which is characterized by comprising the following raw materials, by weight, 5 parts of p-phenylene diamine, 5 parts of terephthaloyl chloride, 30 parts of calcium chloride, 30 parts of N-methylpyrrolidone and 100 parts of deionized water.
  5. 5. A method for preparing a high temperature resistant modified poly-paraphenylene terephthalamide fiber toughener for well cementation according to any one of claims 1-4, comprising the steps of: Step a, obtaining poly (p-phenylene terephthalamide) fibers; And b, improving the poly (p-phenylene terephthamide) fiber obtained in the step a to obtain a modified poly (p-phenylene terephthamide) fiber toughening agent, which comprises the following steps: Step b1, spreading the poly-p-phenylene terephthalamide fibers obtained in the step a under an ultraviolet lamp for irradiation for 8-12 min, and then shearing the poly-p-phenylene terephthalamide fibers into short fibers with the length of 1-5mm to obtain preliminary modified poly-p-phenylene terephthalamide fibers; Step b2, placing the primarily modified poly-p-phenylene terephthalamide fibers into a plasma instrument, and etching the surfaces of the primarily modified poly-p-phenylene terephthalamide fibers by utilizing high-energy particles in the plasma to form a coarse structure to obtain secondarily modified poly-p-phenylene terephthalamide fibers; And b3, placing the secondarily modified poly-p-phenylene terephthalamide fibers in a reaction kettle, introducing SO 3 gas into the kettle, and introducing sulfonic acid groups to the secondarily modified poly-p-phenylene terephthalamide fibers to obtain the modified poly-p-phenylene terephthalamide fiber toughening agent.
  6. 6. The method for preparing the high temperature resistant modified poly (p-phenylene terephthalamide) fiber toughener for well cementation according to claim 5, wherein the step a of obtaining the poly (p-phenylene terephthalamide) fiber comprises the following steps: And a step a1 of weighing the N-methyl pyrrolidone and the calcium chloride, dissolving the N-methyl pyrrolidone and the calcium chloride in a solvent, and uniformly stirring the mixture to obtain a composite solution, wherein the weight ratio of the total weight of the N-methyl pyrrolidone and the calcium chloride to the solvent is 1:10-20. Step a2, weighing the paraphthaloyl chloride and the p-phenylenediamine, adding the paraphthaloyl chloride and the p-phenylenediamine into the composite solution, placing the composite solution into a refrigeration circulation bath for cooling to-10 to-20 ℃, and stirring the mixture at a high speed for 30-60 min to obtain a PPTA solution; Step a3, carrying out centrifugal defoaming on the PPTA solution for 30-90 min to obtain spinning stock solution, then taking water as a coagulating bath, and extruding the centrifugal defoamed spinning stock solution into the coagulating bath by utilizing a microinjection pump to obtain wet fibers; And a4, placing the wet fibers into a beaker filled with deionized water for stirring and cleaning, carrying out suction filtration and drying on the cleaned fibers by using a vacuum suction filter, repeating the steps for a plurality of times, cooling the suction-filtered fibers in a refrigerator for 3-6 h, and drying the cooled fibers for 24-48 h by using a freeze dryer to obtain the poly-p-phenylene terephthalamide fibers.
  7. 7. The method for preparing the high-temperature-resistant modified poly (p-phenylene terephthamide) fiber toughener for well cementation, which is characterized in that the solvent is at least one of clear water and ethanol.
  8. 8. The method for preparing the high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughener for well cementation, according to claim 7, wherein the solvent is ethanol, and the weight ratio of the total weight of N-methylpyrrolidone and calcium chloride to the ethanol is 1:10.
  9. 9. The method for preparing the high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughener for well cementation, which is characterized in that the solvent is clear water, and the weight ratio of the total weight of N-methylpyrrolidone and calcium chloride to the clear water is 1:15.
  10. 10. The method for preparing the high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughener for well cementation, which is disclosed in claim 7, wherein the solvent is a mixed solvent of clear water and ethanol, and the weight ratio of the total weight of N-methylpyrrolidone and calcium chloride to the clear water and the ethanol is 1:10:10.
  11. 11. A well cementation cement slurry is characterized by comprising, by weight, 1-3 parts of the high-temperature-resistant modified poly-p-phenylene terephthalamide fiber toughening agent for well cementation, 100-120 parts of cement, 35-45 parts of quartz sand, 2-4 parts of a high-temperature-resistant recession agent, 1-3 parts of a retarder, 2-4 parts of a suspension stabilizer, 2-4 parts of a filtrate reducer and 44-48 parts of clear water.
  12. 12. A well cementing slurry according to claim 11, wherein the silica sand is composed of 200 mesh acid-washed silica sand and 400 mesh acid-washed silica sand, and the mass ratio of 200 mesh acid-washed silica sand to 400 mesh acid-washed silica sand is 2:1.
  13. 13. A cement slurry according to claim 11, configured in the following manner, comprising the steps of: Step c1, dry-mixing cement, quartz sand and a high-temperature-resistant modified poly-p-phenylene terephthamide fiber toughening agent for well cementation to obtain a mixed dry material; Step c2, uniformly stirring the anti-high Wen Cuitui agent, the retarder, the suspension stabilizer, the fluid loss agent and the water-soluble agent in clear water to obtain a mixed wet material; and c3, adding the mixed dry material obtained in the step c1 into the mixed wet material obtained in the step c2, and uniformly stirring to obtain the well cementation cement paste containing the high-temperature-resistant modified poly-p-phenylene terephthamide fiber toughening agent for well cementation cement.
  14. 14. The cement paste as claimed in claim 13, wherein in step c3, the stirring process is first rotated at a low speed (4000±200 r/min), the weighed dry powder mixture is added within 10-20 s, then a cover of the stirrer is covered, and stirring is continued at a high speed (12000±500 r/min) for 35-40 s, so as to obtain the cement paste containing the high temperature resistant modified poly (p-phenylene terephthamide) fiber toughening agent.

Description

Well cementing cement slurry, high-temperature-resistant modified poly-p-phenylene terephthamide fiber toughening agent for well cementing and preparation method thereof Technical Field The invention relates to the technical field of petroleum and natural gas exploration and development, in particular to a high-temperature-resistant modified poly-p-phenylene terephthamide fiber toughening agent for well cementation cement paste and well cementation and a preparation method thereof. Background As the field of oil and gas exploration continues to advance to deeper levels, the number of complex deep wells continues to increase, the temperatures of the wellbores of these deep wells and ultra-deep wells continue to rise, and the bottom-hole temperatures even exceed 180 ℃. Because the oil well cement stone has brittleness, microcracks are easy to generate in a complex deep well environment so as to weaken the strength of the cement stone, further the integrity of a cement sheath is damaged, the safe operation of an oil gas well is influenced, and even serious economic loss is caused. The sealing performance of the cement sheath is difficult to maintain after curing at high temperature, so that the problem of sealing failure is increasingly serious, and therefore, the development of the well cementation cement paste technology suitable for high temperature environment is important for ensuring the oil gas exploration and development safety of a complex deep well. Under the high-temperature environment, the cement stone has high brittleness and is easy to crack, and the sealing performance of the underground cement sheath can be reduced. To solve this challenge, a toughening agent is generally added to the well cementing slurry in engineering to improve toughness and ductility of the cement paste, thereby enhancing the long-term packing capacity of the well cementing ring. For example, the invention patent 'a light toughening well cementation material and a preparation method thereof' (CN 115872680A) adopts plant fiber, vacuum glass beads and rubber powder as toughening materials, improves the development speed of initial setting strength of the cement stone, ensures that the early strength of the cement stone can reach 7.0MPa, improves the toughness and the impact resistance of the cement stone, and has the elastic modulus of only 4.5-5.6 GPa. In another example, the invention patent of the invention is a preparation method of inorganic fiber toughening agent for oil-gas well cementing cement base (CN 11452119A) which adopts one or more fiber mixtures of nano silicon dioxide modified basalt fiber, carbon fiber, brucite fiber and silicon carbide fiber as toughening materials, thereby effectively reducing brittleness of cement stone and improving mechanical flexibility of cement stone, but the method is not suitable for cementing construction under the ultra-high temperature condition of more than 180 ℃. As another example, the invention patent "a cementing cement for ultra-high temperature deep wells and a preparation method and application thereof" (CN 110563428A) adopts a combination of a first strength-degrading agent silicon powder and a second strength-degrading agent, so that the compressive strength at 200-240 ℃ is not degraded, but the method does not modify the toughness of cement stones. Although the prior art has a certain effect on the mechanical modification of high-temperature-resistant cement, the prior art still has some problems on the toughening of the high-temperature-resistant cement stones, and cannot meet the technical requirements of complex deep well cementation with the bottom hole temperature of more than 180 ℃. Disclosure of Invention The invention provides a high-temperature-resistant modified poly-p-phenylene terephthamide fiber toughening agent for well cementation cement stones and a preparation method thereof, and aims to meet the technical requirement of complex deep well cementation with the bottom hole temperature of more than 180 ℃. The high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughening agent for well cementation is prepared from the following raw materials, by weight, 1-5 parts of p-phenylene diamine, 5-10 parts of terephthaloyl chloride, 5-30 parts of calcium chloride, 5-30 parts of N-methylpyrrolidone and 80-100 parts of deionized water. Further, the high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughening agent for well cementation is prepared from the following raw materials, by weight, 5 parts of p-phenylene diamine, 5 parts of terephthaloyl chloride, 10 parts of calcium chloride, 10 parts of N-methylpyrrolidone and 100 parts of deionized water. Further, the high-temperature-resistant modified poly (p-phenylene terephthalamide) fiber toughening agent for well cementation is prepared from the following raw materials, by weight, 5 parts of p-phenylene diamine, 5 parts of terephthaloyl chloride, 20 parts of ca