CN-122012066-A - Composite acid for acidification and preparation method thereof

Abstract

The invention belongs to the technical field of petroleum exploitation, and particularly relates to a compound acid for acidification and a preparation method thereof. The preparation method comprises the steps of adding 2-naphthylamine-1, 5-disulfonic acid and water into a reactor, stirring, heating and dissolving, adjusting pH to 8-9 by a sodium hydroxide solution, simultaneously dropwise adding carbon disulfide and the sodium hydroxide solution into the reactor, maintaining pH to 8-9 in the reaction process, heating and refluxing after the dropwise adding, cooling the mixture to below 5 ℃, separating out crystals, centrifugally drying to obtain multifunctional acid, adding the multifunctional acid, hydrochloric acid (30wt%), polymaleic anhydride, formic acid, aminotrimethylene phosphonic acid and water into the container, and stirring uniformly to obtain the composite acid. The composite acid for acidification can greatly prolong the acidification time and dissolve deep rock formations, adjust the composition of each component of the composite acid, adjust the acidification speed and meet the acidification requirements of rock formations in different depths.

Inventors

• QI ZHICHAO
• LIN XUEZHI
• DONG JIANXING

Assignees

• 胜利油田华滨化工有限责任公司

Dates

Publication Date

20260512

Application Date

20260303

Claims (7)

1. 1. A composite acid for acidification is characterized in that the composite acid comprises the following components in parts by mass, 10-15 Parts of multifunctional acid; 15-25 parts of hydrochloric acid (30 wt%); 2-5 parts of polymaleic anhydride; 2-5 parts of formic acid; 3-6 parts of amino trimethylene phosphonic acid; the rest is water, and the total weight is 100 parts; the molecular structural formula of the multifunctional acid is as follows: 。
2. 2. The process for producing a complex acid for acidification according to claim 1, wherein, The preparation method comprises the following specific steps: (1) Adding 2-naphthylamine-1, 5-disulfonic acid and water into a reactor, stirring, heating and dissolving, and adjusting pH to 8-9 by sodium hydroxide solution; (2) Simultaneously dropwise adding carbon disulfide and sodium hydroxide solution into the reactor, maintaining the pH value at 8-9 in the reaction process, and heating and refluxing after the dropwise adding is finished; (3) Cooling the mixture to below 5 ℃, precipitating crystals, centrifuging and drying to obtain multifunctional acid; (4) Adding multifunctional acid, hydrochloric acid (30wt%), polymaleic anhydride, formic acid, amino trimethylene phosphonic acid and water into a container, and uniformly stirring to obtain the composite acid.
3. 3. The process according to claim 2, wherein the molar ratio of carbon disulphide to 2-naphthylamine-1, 5-disulphonic acid is between 0.4 and 0.6:1.
4. 4. A process according to claim 3, wherein the molar ratio of carbon disulphide to para-2-naphthylamine-1, 5-disulphonic acid is in the range 0.45 to 0.55:1.
5. 5. The method according to claim 2, wherein in the step (1), the mass ratio of the water to the 2-naphthylamine-1, 5-disulfonic acid is 6-10:1.
6. 6. The process according to claim 2, wherein in step (1), the heating temperature is 50 to 80 ℃.
7. 7. The method of claim 2, wherein in step (2), the heating reflux time is 1 to 4 hours.

Description

Composite acid for acidification and preparation method thereof Technical Field The invention belongs to the technical field of petroleum exploitation, and particularly relates to a compound acid for acidification and a preparation method thereof. Background Acidification is a key yield increasing technology for improving seepage capability of near-wellbore zones through acid liquor chemical corrosion, and has the core effects of effectively relieving various pollution and blockage formed in drilling, operation or production processes, recovering the original permeability of stratum, and simultaneously, actively creating acid corrosion cracks with high diversion by etching rocks (especially in carbonate reservoirs), remarkably improving oil gas flow efficiency and realizing deep transformation. In addition, the technology can also be used for adjusting the output or injection profile of the heterogeneous reservoir to optimize the resource utilization. At present, the acid liquor system for acidification commonly used on site mainly comprises (1) inorganic acid such as hydrochloric acid, which has the advantages of low cost, strong reactivity and strong corrosion capability, but has extremely strong corrosiveness, too high reaction speed and high risk of secondary injury, (2) organic acid such as formic acid and acetic acid, which has the advantages of mild reaction, good retarding effect, lower corrosiveness at high temperature than the inorganic acid, but has weak corrosion capability, limited solubility and poor dissolution effect on partial obstruction, (3) conventional compound acid such as hydrochloric acid and organic acid, which are physically mixed to make up for the strong complement, but has limited synergistic effect, poor system stability and insufficient formula pertinence, and is difficult to adapt to complex and changeable reservoir conditions. Therefore, the novel composite acid for acidification, which realizes high synergy of each component through a scientific formula and a preparation process, has adjustable performance, can adapt to complex reservoir conditions, and the matched preparation method thereof are developed, and have important practical significance and application value for improving the acidification operation effect, ensuring the operation safety and reducing the comprehensive cost. Disclosure of Invention The invention provides a compound acid for acidification and a preparation method thereof, aiming at the defects of the prior art. The compound acid has the functions of adjusting the acidification speed and dissolving rock formations in different depths. The invention discloses an acidification compound acid, which comprises the following components in parts by mass (total 100 parts): 10-15 parts of multifunctional acid; 15-25 parts of hydrochloric acid (30 wt%); 2-5 parts of polymaleic anhydride; 2-5 parts of formic acid; 3-6 parts of amino trimethylene phosphonic acid; the rest is water; the molecular structural formula of the multifunctional acid is as follows: 。 the invention further discloses a preparation method of the composite acid, which comprises the following specific steps: (1) Adding 2-naphthylamine-1, 5-disulfonic acid and water into a reactor, stirring, heating and dissolving, and adjusting pH to 8-9 by sodium hydroxide solution; (2) Simultaneously dropwise adding carbon disulfide and sodium hydroxide solution into the reactor, maintaining the pH value at 8-9 in the reaction process, and heating and refluxing after the dropwise adding is finished; (3) Cooling the mixture to below 5 ℃, precipitating crystals, centrifuging and drying to obtain multifunctional acid; (4) Adding multifunctional acid, hydrochloric acid (30wt%), polymaleic anhydride, formic acid, amino trimethylene phosphonic acid and water into a container, and uniformly stirring to obtain the composite acid. In the present invention, the molar ratio of carbon disulphide to 2-naphthylamine-1, 5-disulphonic acid is preferably in the range 0.4 to 0.6:1, more preferably in the range 0.45 to 0.55:1. Preferably, in the step (1), the mass ratio of the water to the 2-naphthylamine-1, 5-disulfonic acid is 6-10:1. Preferably, in step (1), the heating temperature is 50-80 ℃. Preferably, in the step (2), the heating reflux time is 1-4h. The reaction equation for the synthesis of the multifunctional acid of the invention is as follows: compared with the prior art, the invention has the following advantages and beneficial effects: (1) The complex acid for acidification of the present invention has a plurality of functions. The multifunctional acid reduces the reaction speed of acid rock, increases the effective acting distance of active acid, is a key for realizing deep etching by an acid fracturing technology, inhibits corrosion, forms an adsorption film on the surface of a metal pipe (oil pipe and sleeve), obviously reduces the corrosion rate of acid liquor to steel, assists drainage, reduces the surface