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CN-121991283-A - Drag reducer for shear-resistant high-temperature-resistant salt-resistant fracturing fluid, preparation method and application

CN121991283ACN 121991283 ACN121991283 ACN 121991283ACN-121991283-A

Abstract

The invention discloses a drag reducer for a shear-resistant high-temperature-resistant salt-resistant fracturing fluid, which comprises the following components of 14-19.5% of acrylamide, 3.5-4.8% of 2-acrylamide-2-methylpropanesulfonic acid, 3.5-4.8% of sodium styrenesulfonate, 1.5-2.5% of cetyl dimethyl allyl ammonium chloride, 1.5-2.5% of acryloylmorpholine, 0.05-0.14% of cosolvent urea, 0.025-0.07% of chelating agent ethylene diamine tetraacetic acid, 0.05-0.18% of initiator azo diisobutylamidine hydrochloride and the balance of water. The invention also discloses a preparation method and application of the drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid. The drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid solves the problem that the drag reducing capability of the existing drag reducer is reduced under the conditions of high temperature, high mineralization and high field shear rate.

Inventors

  • LI LI
  • YAN ZHICHEN
  • LIU YI
  • WANG XIANWEN
  • TIAN WEI
  • LI XURI
  • FENG PENGXIN
  • BAI XIAOHONG
  • MA HAIBIN
  • SONG HANHUA

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (8)

  1. 1. The drag reducer for the shearing-resistant high-temperature-resistant salt-resistant fracturing fluid is characterized by comprising the following components of 14-19.5% of acrylamide, 3.5-4.8% of 2-acrylamide-2-methylpropanesulfonic acid, 3.5-4.8% of sodium styrenesulfonate, 1.5-2.5% of cetyl dimethyl allyl ammonium chloride, 1.5-2.5% of acryloylmorpholine, 0.05-0.14% of cosolvent urea, 0.025-0.07% of chelating agent ethylene diamine tetraacetic acid, 0.05-0.18% of initiator azo diisobutylamidine hydrochloride and the balance of water.
  2. 2. The preparation method of the drag reducer for the shearing-resistant high-temperature-resistant salt-resistant fracturing fluid is characterized by comprising the following specific steps: S1, respectively weighing acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, sodium styrene sulfonate, hexadecyl dimethyl allyl ammonium chloride, acryloylmorpholine, cosolvent urea, chelating agent tetra sodium ethylenediamine tetraacetate, initiator azo diisobutylamidine hydrochloride and the balance deionized water; s2, adding acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and sodium styrenesulfonate into deionized water, stirring for the first time until the mixture is fully dispersed, adjusting the pH value, adding acryloylmorpholine, and stirring for the second time until the mixture is fully dispersed to obtain a dispersion solution; s3, transferring the dispersion solution to a container for condensation reflux, and sequentially adding cetyl dimethyl allyl ammonium chloride, cosolvent urea and initiator azo diisobutylamidine hydrochloride under the nitrogen atmosphere to obtain reflux liquid; s4, cooling the reflux liquid to 50 ℃, adding tetra sodium ethylenediamine tetraacetate, and stirring for reaction to obtain gel-state liquid; s5, cooling the gel state liquid to room temperature, diluting and dissolving, adding anhydrous acetone to obtain a precipitate, soaking the precipitate in acetone, purifying, vacuum drying and crushing to obtain the drag reducer for the shearing-resistant high-temperature-resistant salt-resistant fracturing fluid.
  3. 3. The method for preparing the drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid according to claim 2, wherein the S1 comprises, by mass, 14-19.5% of acrylamide, 3.5-4.8% of 2-acrylamide-2-methylpropanesulfonic acid, 3.5-4.8% of sodium styrenesulfonate, 1.5-2.5% of cetyl dimethyl allyl ammonium chloride, 1.5-2.5% of acryloylmorpholine, 0.05-0.14% of cosolvent urea, 0.025-0.07% of chelating agent ethylene diamine tetraacetic acid, 0.05-0.18% of initiator azo diisobutylamidine hydrochloride, and the balance deionized water.
  4. 4. The method for preparing the drag reducer for the shearing-resistant high-temperature-resistant salt-resistant fracturing fluid, which is disclosed in claim 2, is characterized in that the pH of the solution is regulated to 7-8 by a pH regulator in S2, and then the acryloylmorpholine is added.
  5. 5. The preparation method of the drag reducer for the shearing-resistant high-temperature-resistant salt-resistant fracturing fluid, which is disclosed in claim 2, is characterized in that the specific method S3 comprises the steps of transferring the dispersion solution into a container for condensation reflux, keeping stirring, wherein the stirring speed is 500-1500 rpm, introducing nitrogen for 15min, adding cetyl dimethyl allyl ammonium chloride, heating to 70 ℃, adding cosolvent urea and initiator azobisisobutyronium chloride, continuing introducing nitrogen for 35min, and reacting for 4-6h to obtain reflux liquid.
  6. 6. The method for preparing the drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid according to claim 2, wherein the stirring speed in the step S4 is 500rpm-1500rpm, and the stirring reaction time in the step S4 is 2-2.5 h.
  7. 7. The method for preparing the drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid according to claim 2, wherein the specific step of S5 is as follows: And cooling the gel state liquid to room temperature, diluting and dissolving the gel state liquid by using water, adding anhydrous acetone for precipitation to obtain a precipitate, soaking the precipitate in the acetone for 24-30 h, and then extracting and purifying the precipitate in ethanol under reflux for 12h to obtain a purified product.
  8. 8. The use of the drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid according to any one of claims 1 to 7 in slickwater fracturing fluid.

Description

Drag reducer for shear-resistant high-temperature-resistant salt-resistant fracturing fluid, preparation method and application Technical Field The invention belongs to the technical field of old well fracturing modification of oil and gas well reservoirs, and particularly relates to a drag reducer for a shear-resistant high-temperature-resistant salt-resistant fracturing fluid. Background Compact oil gas isohypotonic/ultra hypotonic low-grade resources are important successor energy sources, and the reserves are very rich, and the ratio of the reserves exceeds more than six. Shale oil and gas is a potential unconventional natural gas resource in recent years and has become a popular field for world oil and gas exploration and development. For the initial transformation and the later repeated transformation of shale oil and gas reservoirs, the slick water fracturing technology is mainly adopted at home and abroad, the drag reducer is the most main additive in slick water fracturing fluid and is a key component in a slick water fracturing fluid system, friction resistance can be greatly reduced in the slick water system, high-pressure requirements on fracturing construction equipment are effectively reduced, net pressure on reservoir rocks is increased, and fracturing construction effect is improved. However, in the field construction at the present stage, high-mineralization degree groundwater is often used for preparing liquid, and the ground layer is at high temperature, so that the performance of the conventional slick water resistance reducing agent is seriously reduced. In addition, the liquid discharge capacity is large during slickwater fracturing, the shearing rate of liquid in a pipe column is up to 1000-3000 s < -1 >, the shearing resistance of a common drag reducer is poor, and a molecular chain is easy to break. Therefore, it is highly desirable to develop a shear resistant, high temperature resistant, salt drag reducer. The invention discloses a drag reducer for temperature-resistant and high-mineralization-resistant slickwater fracturing fluid and a preparation method thereof, and the drag reducer can play a good drag reducing effect at 130 ℃,15 ten thousand mineralization and 170s < -1 > shearing rate. The invention discloses a method for preparing a carbon point with temperature resistance, salt resistance and drag reduction performance, a product and application thereof, and a Chinese patent application publication No. CN114835105A, wherein the application date is 2022, 5 and 20, and the Chinese patent application publication No. CN114835105A discloses a method for preparing a carbon point with temperature resistance, salt resistance and drag reduction performance, a product and application thereof, and the drag reducer can effectively reduce drag under the conditions of 90 ℃, 20wt% NaCl and 3wt% CaCl 2. The invention discloses a temperature-resistant salt-resistant brine pipeline drag reducer and a preparation method thereof, wherein the application date is 5 to 16 in 2016, and the Chinese patent publication number CN105777984A discloses the temperature-resistant salt-resistant brine pipeline drag reducer and the preparation method thereof, and the drag reducer has a drag reduction rate of 45.3 percent under the conditions that the temperature is 25 ℃, the flow is 960L/h, the salt content is 150g/L of simulated brine and the consumption of the drag reducer is 20 ppm. None of the above drag reducers exhibit effective drag reduction capabilities at higher temperatures, higher salt concentrations, or higher shear rates. Disclosure of Invention The invention aims to provide a drag reducer for a shear-resistant high-temperature-resistant salt-resistant fracturing fluid, which solves the problem that the drag reducing capability of the existing drag reducer is reduced under the conditions of high temperature, high mineralization and high on-site shear rate. The second purpose of the invention is to provide a preparation method of the drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid. The third object of the invention is to provide the application of the drag reducer for the shear-resistant high-temperature-resistant salt-resistant fracturing fluid. The drag reducer for the shearing-resistant high-temperature-resistant salt-resistant fracturing fluid comprises, by weight, 14-19.5% of acrylamide, 3.5-4.8% of 2-acrylamide-2-methylpropanesulfonic acid, 3.5-4.8% of sodium styrenesulfonate, 1.5-2.5% of cetyl dimethylallyl ammonium chloride, 1.5-2.5% of acryloylmorpholine, 0.05-0.14% of cosolvent urea, 0.025-0.07% of chelating agent ethylene diamine tetraacetic acid, 0.05-0.18% of initiator azo diisobutylamidine hydrochloride, and the balance of water. The second technical scheme adopted by the invention is that the preparation method of the drag reducer for the shearing-resistant high-temperature-resistant salt-resistant fracturing fluid comprises the foll