Search

CN-121991679-A - Low-temperature activated nano composite cross-linking agent, fracturing fluid, preparation method and application

CN121991679ACN 121991679 ACN121991679 ACN 121991679ACN-121991679-A

Abstract

The invention discloses a low-temperature activated nano composite cross-linking agent, a fracturing fluid and a preparation method and application thereof, and belongs to the technical field of fracturing, wherein the nano composite cross-linking agent comprises, by weight, 84-89.5 parts of organoboron zirconium, 0.5-1 part of hydrophilic modified graphene oxide and 10-15 parts of low-temperature activated auxiliary agents, the hydrophilic modified graphene oxide is selected from 6-amino-4-hydroxy-2-naphthalene sulfonic acid modified graphene oxide, and the low-temperature activated auxiliary agents are selected from at least one of ammonium chloride, sodium dodecyl benzene sulfonate, sodium hexadecyl sulfonate, dodecyl dimethyl benzyl ammonium chloride, octadecyl dimethyl tertiary amine hydrochloride and dioctadecyl methyl tertiary amine hydrochloride. The nano composite cross-linking agent disclosed by the invention is applied to fracturing fluid, has the advantages of high low-temperature cross-linking speed, excellent temperature and shear resistance, thorough gel breaking, small damage to a reservoir and the like, and is suitable for fracturing reconstruction operation of low-temperature low-permeability oil and gas reservoirs.

Inventors

  • PU DI
  • ZOU CHUNYAN
  • ZHOU KANGWEN
  • GUO YONGJUN
  • WANG YAHENG
  • MA JIE
  • ZHENG XIAOJUN
  • WANG SHIXIANG

Assignees

  • 新疆光亚油气新技术发展有限公司

Dates

Publication Date
20260508
Application Date
20260410

Claims (10)

  1. 1. The low-temperature activated nano composite cross-linking agent is characterized by comprising, by weight, 84-89.5 parts of organoboron zirconium, 0.5-1 part of hydrophilically modified graphene oxide and 10-15 parts of low-temperature activated auxiliary agents; the hydrophilic modified graphene oxide is selected from 6-amino-4-hydroxy-2-naphthalene sulfonic acid modified graphene oxide; The low-temperature activating auxiliary agent is at least one selected from ammonium chloride, sodium dodecyl benzene sulfonate, sodium hexadecyl sulfonate, dodecyl dimethyl benzyl ammonium chloride, octadecyl dimethyl tertiary amine hydrochloride and dioctadecyl methyl tertiary amine hydrochloride.
  2. 2. The low-temperature activated nanocomposite crosslinking agent according to claim 1, wherein the organoboron zirconium is obtained by reacting zirconium oxychloride in a mixed solution of a polyol and water with an organic acid, an organic alcohol amine and boric acid at 50-60 ℃.
  3. 3. The low temperature activated nanocomposite crosslinker of claim 2, wherein the polyol is selected from at least one of ethylene glycol, propylene glycol, glycerol, sorbitol, and xylitol; Or/and, the organic acid is at least one of lactic acid, citric acid, tartaric acid and salicylic acid; or/and the organic alcohol amine is at least one selected from diethanolamine and triethanolamine.
  4. 4. A method for preparing a low temperature activated nanocomposite crosslinker according to any of claims 1-3, comprising: And carrying out ultrasonic treatment on the organoboron zirconium, the hydrophilic modified graphene oxide and the low-temperature activating auxiliary agent according to parts by weight under a heating condition to obtain the stable and uniform nano composite cross-linking agent, wherein the heating temperature is 40-60 ℃.
  5. 5. The method of preparing a hydrophilically modified graphene oxide according to claim 4, comprising: ultrasonic dispersing graphene oxide in water to form GO dispersion liquid, and regulating 6-amino-4-hydroxy-2-naphthalene sulfonic acid to be neutral or weak alkaline by adopting inorganic alkali aqueous solution to form AS aqueous solution; continuously stirring the AS aqueous solution, simultaneously adding 5-10 mL/min into the GO dispersion liquid, and continuously stirring and carrying out reflux reaction at 70-90 ℃; And after the reaction is finished, centrifuging the mixed solution after the reaction, and taking supernatant and drying to obtain the hydrophilic modified graphene oxide.
  6. 6. The preparation method of claim 5, wherein the mass ratio of graphene oxide to 6-amino-4-hydroxy-2-naphthalene sulfonic acid is 1:5-10; Or/and, the pH of the AS aqueous solution is 7-9; Or/and the reflux reaction is carried out for 8-12 hours; or/and, centrifuging for 10-20 min under the condition of 2000-4000 r/min; Or/and, the drying is carried out under the vacuum condition at 0 ℃.
  7. 7. The method of preparing according to claim 4, wherein the method of preparing organoboron zirconium comprises: And dissolving zirconium oxychloride in a mixed solution of water and polyalcohol, adding organic acid, organic alcohol amine and boric acid, heating to 50-60 ℃, stirring and maintaining the temperature for reaction to obtain the organic zirconium borate.
  8. 8. The preparation method of the zirconium oxychloride, the organic acid, the organic alcohol amine, the boric acid, the water and the polyol are prepared according to the mass ratio of (8-12): (3-5): (10-15): (6-8): (40-58): (15-20); Or/and the reaction time is 5-8 h.
  9. 9. The use of a low temperature activated nanocomposite crosslinker according to any one of claims 1-3 in hydraulic fracturing, wherein the nanocomposite crosslinker is capable of initiating crosslinking in a low temperature environment of-5~0 ℃.
  10. 10. A polymer fracturing fluid system comprising the low temperature activated nanocomposite crosslinker of any of claims 1-3.

Description

Low-temperature activated nano composite cross-linking agent, fracturing fluid, preparation method and application Technical Field The invention belongs to the technical field of fracturing, and particularly relates to a low-temperature activated nano composite cross-linking agent, fracturing fluid, a preparation method and application. Background Hydraulic fracturing is a mining technique that forms fractures by injecting high pressure fluids into subterranean formations to increase the permeability of hydrocarbons. In the hydraulic fracturing development of deep and ultra-high temperature (200 ℃) oil and gas reservoirs, the construction of efficient diversion cracks is a key for realizing economic exploitation. However, this technology has long faced the extreme temperature differential challenges of low surface temperatures and high reservoir temperatures. In particular in winter or high latitude areas, the surface temperature can be reduced below-10 ℃ and the target reservoir temperature is as high as 200 ℃, which puts near contradictory full flow requirements on fracturing fluid performance. For certain special reservoirs (e.g., high pH alkaline environments), conventional guar gum (guar gum) fracturing fluids are not suitable due to their chemical stability limitations. Compared with the method, the synthetic polymer fracturing fluid (such as polyacrylamide) has strong designability of molecular structure, good compatibility with formation fluid, low residue after gel breaking and low friction pumping, and becomes a research hot spot and an advantage technical direction of ultra-high temperature well fracturing. However, the polymer fracturing fluid has two interrelated core bottlenecks, namely first low-temperature crosslinking failure, when dealing with the wide-temperature-range working condition. The reaction of carboxyl and other crosslinking sites on the molecular chain of the polymer and metal crosslinking agents (such as zirconium and titanium) has higher activation energy, and the reaction kinetics is obviously retarded in a low-temperature environment below 10 ℃, so that a three-dimensional gel network with sufficient sand carrying strength cannot be formed, and the risks of proppant settlement and sand blockage are caused. Second, rheology and temperature resistance are difficult to synergistically optimize. In order to meet the long-acting thermal stability of a 200 ℃ reservoir, the concentration or molecular weight of a polymer is often required to be improved, but the viscosity of a base fluid is excessively high and the hanging property is strong under the low-temperature condition, so that pumping friction is increased rapidly and construction pressure is excessively high, and a 'injection-free' process dilemma is formed. Therefore, although the current technical research is aimed at improving the temperature resistance or delaying the crosslinking characteristic of the polymer, how to intelligently and cooperatively solve a series of contradictions of low-temperature pumpability, low-temperature reliable crosslinking and ultra-high-temperature long-term stability in the same system is still a prominent technical blank. The Chinese patent with publication number CN 104560003A discloses an organic boron zirconium cross-linking agent, which mainly solves the problems of high raw material cost (using cheap inorganic zirconium salt to replace expensive organic zirconium complex) and complex preparation process, and the performance target points to the temperature resistance above 135 ℃. The Chinese patent with publication number CN 119331594A discloses a multi-stage crosslinking organoboron crosslinking agent for resisting high temperature of 180 ℃ and a preparation method thereof, which mainly solves the problems of temperature resistance and shearing resistance of guanidine gum fracturing fluid under ultra-high temperature (180 ℃) of a deep well, realizes delayed crosslinking through multi-stage chelation to reduce friction resistance, and has the focus of extreme high temperature performance and no mention or solution of the problem of crosslinking activation under low temperature environment. Chinese patent publication No. CN 119242288A discloses a preparation method of high temperature resistant and shear resistant organoboron zirconium cross-linking agent, which is resistant to 155 ℃ at maximum, but the type of the fracturing fluid is not clear. The Chinese patent with publication number CN 109971451A discloses a graphene oxide nano cross-linking agent for fracturing fluid and a preparation method thereof, which mainly solve the problems of difficult gel breaking, poor flowback and more residues of the traditional cross-linking agent, realize shearing dilution and quick flowback through reversible non-covalent bond cross-linking, and have a temperature-resistant target of 166 ℃. The Chinese patent with publication number CN 112251204A discloses a nano cellulose cross-linking agent fo