Search

CN-121975508-A - Foaming agent for oil field and preparation method thereof

CN121975508ACN 121975508 ACN121975508 ACN 121975508ACN-121975508-A

Abstract

The invention belongs to the technical field of petroleum exploitation, and particularly relates to a foaming agent for an oil field and a preparation method thereof. The preparation method comprises the specific steps of (1) sequentially adding melamine and pyridine, (3-chloro-2-hydroxypropyl) dodecyl dimethyl ammonium chloride into a reactor, carrying out heat preservation reaction, (2) adding 12-bromododecanoic acid into the reactor, carrying out heat preservation reaction, (3) adding dichloroalkane into the reactor, carrying out heat preservation reaction, and (4) carrying out reduced pressure distillation on the mixed solution to obtain a viscous solid, washing 2-3 times with a small amount of 1mol/L hydrochloric acid, separating the solid, adding sodium hydroxide solution, regulating pH to 7-8, carrying out reduced pressure distillation to obtain the solid, drying, and grinding to obtain the foaming agent. The foaming agent has the advantages of large foaming volume, long liquid separation half-life period and large liquid carrying rate.

Inventors

  • Xun Guangjian
  • CHENG WENJIA
  • ZHENG FENGJUAN

Assignees

  • 胜利油田华滨化工有限责任公司

Dates

Publication Date
20260505
Application Date
20260128

Claims (9)

  1. 1. The preparation method of the foaming agent for the oil field is characterized by comprising the following specific steps: (1) Sequentially adding melamine and pyridine, (3-chloro-2-hydroxypropyl) dodecyl dimethyl ammonium chloride into a reactor, and carrying out heat preservation reaction; (2) Adding 12-bromododecanoic acid into the reactor, and reacting at a constant temperature; (3) Adding dichloroalkane into the reactor, and reacting at a constant temperature; (4) Distilling the mixed solution under reduced pressure to obtain viscous solid, washing 2-3 times with a small amount of 1mol/L hydrochloric acid, separating out solid, adding sodium hydroxide solution, adjusting pH to 7-8, distilling under reduced pressure to obtain solid, oven drying, and grinding to obtain foaming agent; The (3-chloro-2-hydroxypropyl) dodecyldimethyl ammonium chloride, 12-bromododecanoic acid and dichloroalkane are used in an amount of 0.8 to 1.2 mol parts, 0.8 to 1.2 mol parts and 0.4 to 0.6mol parts, respectively, based on 1mol part of melamine.
  2. 2. The process according to claim 1, wherein the amount of (3-chloro-2-hydroxypropyl) dodecyldimethylammonium chloride, 12-bromododecanoic acid and dichloroalkane is 0.9 to 1.1 mol parts, 0.9 to 1.1 mol parts and 0.45 to 0.55 mol parts, respectively, based on 1mol part of melamine.
  3. 3. The method according to claim 1, wherein the alkyl group of the dichloroalkane is a linear alkyl group of C 3 -C 10 .
  4. 4. The process of claim 1, wherein in step (1), the weight ratio of pyridine to melamine is 50-80:1.
  5. 5. The method according to claim 1, wherein in the step (1), the temperature of the incubation reaction is 50-70 ℃ for 0.5-2 hours.
  6. 6. The method according to claim 1, wherein in the step (2), the temperature of the incubation reaction is 60-80 ℃ for 1-4 hours.
  7. 7. The method according to claim 1, wherein in the step (3), the temperature of the incubation reaction is 80-100 ℃ for 4-12 hours.
  8. 8. An oilfield foaming agent prepared by the preparation method according to any one of claims 1 to 7.
  9. 9. The oilfield foaming agent of claim 7, wherein the foaming agent has the molecular structure as follows: , R is Straight chain alkyl of (a).

Description

Foaming agent for oil field and preparation method thereof Technical Field The invention belongs to the technical field of petroleum exploitation, and particularly relates to a foaming agent for an oil field and a preparation method thereof. Background With the continuous deep exploitation of global oil and gas resources, the yield of conventional oil reservoirs is gradually decreased year by year, and the efficient development of heavy oil, super heavy oil, high water content oil reservoirs and low permeability oil reservoirs has become the key of stable yield and yield increase of oil fields. Among the technologies of improving recovery efficiency, the technologies of foam flooding, foam profile control, air foam flooding, foam fracturing and the like are widely applied because the technologies of effectively improving fluidity ratio, expanding swept volume and improving oil displacement efficiency. In these techniques, the performance of the blowing agent is critical. And after the foaming agent is added, the gas-liquid interfacial tension is reduced, stable foam is formed, the bottom hole liquid phase is continuously consumed, the foam is discharged with the liquid after the continuous gas phase pushes the liquid to rise to the wellhead, the accumulated liquid is reduced, the foam quality in the oil pipe is continuously distributed along with the pressure, and the optimization of the gas-liquid structure is realized. The density of the mixed fluid is reduced, the liquid phase in the oil pipe is continuously reduced under the action of the foam liquid, the relative density of the mixed fluid is obviously reduced, the back pressure during the production of the oil well is reduced, and the production pressure difference is increased, so that the yield of the oil well is improved. And the damage of a gas layer is reduced, and the residual surfactant at the bottom of the well is helpful for reducing the damage of the gas layer and protecting the oil and gas reservoir. The friction loss is regulated, namely, the friction loss of the gas-water (oil) co-production well is closely related to the gas-liquid interfacial tension, the gas-liquid interfacial tension is reduced after the foaming agent is added, the liquid velocity number, the gas velocity number, the oil pipe diameter number and the liquid viscosity number describing multiphase pipe flow are all reduced, and the friction loss can be reduced. CN112980419A discloses a foaming agent for thick oil, a preparation method and application thereof, wherein the foaming agent for thick oil comprises, by mass, 18-21% of an amphoteric surfactant, 6-9% of an anionic surfactant and the balance of water, wherein the amphoteric surfactant is obtained by stepwise reaction of coconut oil acid, N, -dimethyl-1, 3-diaminopropane and sodium alkyl hydroxysulfonate. The foaming agent for thick oil has simple composition, excellent foamability under the conditions of high temperature and high salt, and has the characteristics of high stability, strong plugging property and obvious viscosity reduction under the conditions of high temperature and high salt. However, the half-life of the foaming agent of the invention is only tens of seconds, which can lead to the reduction of liquid carrying capacity and affect the liquid discharge efficiency. CN104312563B discloses a surfactant for cationic microbubble drilling fluid and a preparation method thereof, wherein the surfactant is prepared by mixing vinyl cationic monomer and vinyl amide compound according to the mass ratio of 10:1-10, adding a relative molecular mass regulator, and carrying out free radical copolymerization, wherein the average relative molecular mass is 1000-4000. However, the foaming performance and the foam stabilizing performance of the invention are relatively insufficient, and the effect in practical application is difficult to meet the field requirement. Disclosure of Invention The invention provides a foaming agent for an oil field and a preparation method thereof aiming at the defects of the prior art. The foaming agent has the advantages of large foaming volume, long liquid separation half-life period and large liquid carrying rate. The invention discloses a preparation method of a foaming agent for an oil field, which comprises the following specific steps: (1) Sequentially adding melamine and pyridine, (3-chloro-2-hydroxypropyl) dodecyl dimethyl ammonium chloride into a reactor, and carrying out heat preservation reaction; (2) Adding 12-bromododecanoic acid into the reactor, and reacting at a constant temperature; (3) Adding dichloroalkane into the reactor, and reacting at a constant temperature; (4) Distilling the mixed solution under reduced pressure to obtain viscous solid, washing with small amount of 1mol/L hydrochloric acid for 2-3 times, separating solid, adding sodium hydroxide solution, adjusting pH to 7-8, distilling under reduced pressure to obtain solid, oven drying, and grinding to obtain f