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CN-121991664-A - Water shutoff profile control agent for low-permeability oil reservoir and preparation method thereof

CN121991664ACN 121991664 ACN121991664 ACN 121991664ACN-121991664-A

Abstract

The invention discloses a low-permeability oil reservoir water shutoff profile control agent and a preparation method thereof, wherein the low-permeability oil reservoir water shutoff profile control agent comprises, by weight, 20-30 parts of carboxymethyl cellulose, 30-40 parts of fumaropimaric acrylamide, 1-2 parts of a surfactant, 0.5-1 part of an initiator and 5-10 parts of a cross-linking agent. According to the invention, the low permeability oil deposit water shutoff profile control agent is obtained after carboxymethyl cellulose and fumaron base acrylamide are crosslinked, and has higher shutoff rate at different temperatures, because the fumaron base acrylamide is added, the low permeability oil deposit water shutoff profile control agent has higher temperature resistance and higher shutoff rate, and the prepared low permeability oil deposit water shutoff profile control agent has stronger gel strength, because the carboxymethyl cellulose and the fumaron base acrylamide form space network crosslinking, the gel strength is higher, and on the other hand, the fumaron base acrylamide can be used as a crosslinking agent, so that the gel forming time is further improved.

Inventors

  • LI XIANG
  • XIE LEI
  • WEI TING
  • XIE HUI
  • ZHANG HANQING
  • MA JIFENG
  • Ding yajie
  • CAO QIANQIAN
  • HAN ZIJIAN

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (10)

  1. 1. The low permeability oil reservoir water shutoff profile control agent is characterized by comprising the following components in parts by weight: 20-30 parts of carboxymethyl cellulose; 30-40 parts of fumaropimaric acrylamide; 1-2 parts of a surfactant; 0.5-1 part of an initiator; 5-10 parts of a cross-linking agent.
  2. 2. The low permeability reservoir water shutoff profile control agent of claim 1, wherein the surfactant is sodium dodecyl sulfate.
  3. 3. The water shutoff profile control agent of a hypotonic oil reservoir of claim 1, wherein the initiator is at least one of ammonium persulfate, sodium bisulphite, potassium persulfate or azodiiso Ding Mi hydrochloride; the cross-linking agent is an organic chromium cross-linking agent.
  4. 4. The low permeability reservoir water shutoff profile control agent of claim 1, wherein the fumaropimaric acrylamide is prepared by the following steps: Adding fumaropimaric acid into thionyl chloride to prepare fumaropimaric acid acyl chloride, introducing ammonia gas, reacting for 4-8 hours at 0-25 ℃ to obtain fumaropimaric amide, adding an acid binding agent, and adding acryloyl chloride to react for 1-3 hours at 20-40 ℃ to obtain fumaropimaric acrylamide.
  5. 5. The low permeability reservoir water shutoff profile control agent of claim 4, wherein the molar ratio of the fumaropimaric acid to the thionyl chloride is 1:3-1:8, the reaction temperature of the fumaropimaric acid and the thionyl chloride is 0-30 ℃, and the reaction time is 1-3 hours.
  6. 6. The water shutoff profile control agent of a hypotonic oil reservoir of claim 4, wherein the acid binding agent is triethylamine.
  7. 7. The low permeability reservoir water shutoff profile control agent of claim 4, wherein the molar ratio of fumaropimaric amide to acryloyl chloride is 1:3-1:6.
  8. 8. A method for preparing the low permeability reservoir water shutoff profile control agent according to any one of claims 1 to 7, wherein the method comprises the following steps: s1, preparing fumaropimaric acrylamide Adding fumaropimaric acid into thionyl chloride to prepare fumaropimaric acid acyl chloride, wherein the molar ratio of the fumaropimaric acid to the thionyl chloride is 1:3-1:8; Introducing ammonia gas into fumaropimaric acid chloride, and reacting for 4-8 hours at 0-25 ℃ to obtain fumaropimaric amide; Adding an acid binding agent into fumaropimaric amide, and adding acryloyl chloride at 20-40 ℃ for reaction for 1-3 hours to obtain fumaropimaric acrylamide, wherein the molar ratio of the fumaropimaric amide to the acryloyl chloride is 1:3-1:6; S2, preparing a water shutoff profile control agent for a low-permeability oil reservoir Adding 20-30 parts by weight of carboxymethyl cellulose into water, stirring for 30-60 min, adding 1-2 parts by weight of surfactant, continuously stirring for 30-60 min, adding 30-40 parts by weight of fumaropimaric acrylamide prepared by S1, 0.5-1 part by weight of initiator and 5-10 parts by weight of cross-linking agent, and stirring and reacting for 1-3 h to obtain the low permeability oil reservoir water shutoff profile control agent.
  9. 9. The method for preparing the low permeability reservoir water shutoff profile control agent according to claim 8, wherein the acid binding agent is triethylamine, and the mass ratio of the acid binding agent to the acrylic chloride is (0.3-1): 1.
  10. 10. The method for preparing the low permeability reservoir water shutoff profile control agent according to claim 8, wherein in the step S2, the reaction temperature is 30-50 ℃.

Description

Water shutoff profile control agent for low-permeability oil reservoir and preparation method thereof Technical Field The invention belongs to the technical field of water shutoff and profile control agents, and particularly relates to a low-permeability oil reservoir water shutoff and profile control agent and a preparation method thereof. Background Along with the extension of construction time, the low permeability oil field generally has the advantages of reduced crude oil yield and increased comprehensive water content. Along with the increase of the water injection quantity, the injected water also forms a water flow dominant channel, so that the injected water has smaller wave and volume, and the oil well yield is reduced. The water shutoff profile control agent is injected into the water injection well, which is a main method for plugging permeable layers of oil fields at home and abroad. Whether water shutoff or profile control, chemical plugging agents are currently the most effective. The plugging agent can be divided into a granular plugging agent, a foam plugging agent, a resin plugging agent and a gel plugging agent. The invention patent with publication number CN116589637A discloses a profile control water shutoff agent, a preparation method and application thereof, wherein the method comprises the steps of mixing cellulose compounds, acrylamide and water, then adding a cross-linking agent, and then adding an initiator to perform polymerization reaction; mixing with metal salt solution to obtain the profile control water shutoff agent. Compared with the existing profile control water shutoff agent product, the hydrogel material with the unique double-network structure has good stability and still keeps better strength under the high-temperature and high-salt condition, but is prepared by taking the petrochemical product acrylamide as the main raw material, and has no environmental friendliness. Therefore, it is important to develop an environment-friendly profile control water shutoff agent. Disclosure of Invention The invention aims to overcome the defect of poor plugging property in the prior art, thereby providing a low-permeability oil reservoir water shutoff profile control agent and a preparation method thereof, wherein natural products are used as main raw materials to obtain the low-permeability oil reservoir water shutoff profile control agent with good temperature resistance. The invention provides a water shutoff profile control agent for a low permeability oil reservoir, which comprises the following raw materials: 20-30 parts of carboxymethyl cellulose; 30-40 parts of fumaropimaric acrylamide; 1-2 parts of a surfactant; 0.5-1 part of an initiator; 5-10 parts of a cross-linking agent. Preferably, the surfactant is sodium dodecyl sulfate, and the initiator is at least one of ammonium persulfate, sodium bisulphite, potassium persulfate or azodiiso Ding Mi hydrochloride. Preferably, the crosslinking agent is an organochromium crosslinking agent. The invention also provides a preparation method of the low permeability oil reservoir water shutoff profile control agent, which comprises the following steps: (1) Adding fumaropimaric acid into sulfoxide chloride to prepare fumaropimaric acid acyl chloride, introducing ammonia gas, reacting for 4-8 hours at 0-25 ℃ to obtain fumaropimaric amide, adding an acid binding agent, and adding acryloyl chloride to react for 1-3 hours at 20-40 ℃ to obtain fumaropimaric acrylamide; (2) Adding carboxymethyl cellulose into water, stirring for 30-60 min, adding a surfactant, continuously stirring for 30-60 min, adding fumaropimaric acrylamide, an initiator and a cross-linking agent, and stirring for reacting for 1-3 h to obtain the low permeability oil reservoir water shutoff profile control agent. Preferably, the molar ratio of the fumaropimaric acid to the thionyl chloride is 1:3-1:8, the reaction temperature of the fumaropimaric acid and the thionyl chloride is 0-30 ℃, and the reaction time is 1-3 h. Preferably, the acid binding agent is triethylamine. Preferably, the molar ratio of the fumaropimaric amide to the acryloyl chloride is 1:3-1:6. Preferably, the reaction temperature in the step (2) is 30-50 ℃. By adopting the technical scheme, the invention has the following beneficial effects: 1. The water shutoff profile control agent for the low-permeability oil reservoir uses natural products as main raw materials, and improves the temperature resistance, the plugging rate and the gel forming strength of the water shutoff profile control agent for the low-permeability oil reservoir through modification of the natural products; 2. According to the preparation method of the low permeability oil deposit water shutoff and profile control agent, the low permeability oil deposit water shutoff and profile control agent is obtained after carboxymethyl cellulose and fumaron-based acrylamide are crosslinked, and has higher shutoff rate at different temperatures