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CN-122012056-A - Non-acid type composite blocking remover and preparation method and application thereof

CN122012056ACN 122012056 ACN122012056 ACN 122012056ACN-122012056-A

Abstract

The invention belongs to the technical field of oilfield development and production increase blocking removal, and particularly relates to a non-acid type composite blocking remover, a preparation method and application thereof. The non-acid type composite blocking remover comprises, by weight, 1-4wt% of a non-ionic surfactant, 0.5-3wt% of an anionic surfactant, 0.5-3wt% of a metal chelating agent, 0.5-2wt% of caustic soda flakes, 2-6wt% of sodium carbonate and the balance of water. The non-acid composite blocking remover has the advantages of high descaling speed and low-concentration scale dissolving capacity, and can achieve the descaling rate of 100 percent for oil wells, and under the synergistic effect of proper proportion of nonionic surfactant, anionic surfactant, metal chelating agent, caustic soda flake, soda ash and water, the composite scale in the stratum is dissolved, and a reservoir blocked by inorganic and organic composite scale is opened, so that the water injection amount of a water injection well or the acidizing yield of an oil-water well is increased.

Inventors

  • LIU YIN
  • CHEN HUILEI
  • YANG TINGAN
  • YAN JIANBO
  • LI XIN
  • HUA LIANG
  • LI ZHIHUI
  • HUANG DEHUI
  • CAO YU
  • GAO YAN

Assignees

  • 中国石油集团渤海钻探工程有限公司
  • 中国石油天然气集团有限公司

Dates

Publication Date
20260512
Application Date
20241111

Claims (10)

  1. 1. The non-acid type composite blocking remover is characterized by comprising, by weight, 1-4wt% of a non-ionic surfactant, 0.5-3wt% of an anionic surfactant, 0.5-3wt% of a metal chelating agent, 0.5-2wt% of caustic soda flakes, 2-6wt% of sodium carbonate and the balance of water.
  2. 2. The non-acid type composite blocking remover according to claim 1, wherein the nonionic surfactant comprises one or more of laurylamine polyoxyethylene ether, octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, glyceride and sorbitol ester.
  3. 3. The non-acid type composite blocking remover according to claim 1, wherein the anionic surfactant comprises one or more of sodium dodecyl benzene sulfonate, sodium lauryl sulfate, fatty alcohol polyoxyethylene ether sulfate and alkyl alcohol polyoxyethylene ether phosphate.
  4. 4. The non-acid type composite blocking remover according to claim 1, wherein the metal chelating agent comprises one or more of tetra sodium ethylenediamine tetraacetate, amine citrate salt, pentasodium diethylenetriamine pentaacetate and sodium ethylenediamine tetraacetate.
  5. 5. The non-acid type composite plugging removing agent according to any one of claims 1 to 4, wherein the pH value of the non-acid type composite plugging removing agent is in the range of 10 to 12.5.
  6. 6. A method for preparing the non-acid type composite blocking remover according to any one of claims 1 to 5, comprising the steps of: Mixing nonionic surfactant and water in proportion, stirring uniformly, continuously adding anionic surfactant in proportion, stirring uniformly, adding metal chelating agent in proportion, stirring uniformly, adding caustic soda flakes in proportion, stirring uniformly, adding sodium carbonate in proportion, and stirring until completely dissolving to obtain the non-acid composite blocking remover.
  7. 7. The method according to claim 6, wherein the stirring rate after mixing the nonionic surfactant and water is 30 to 60 rpm, the stirring time is 20 to 60 minutes, and/or the stirring rate after adding the anionic surfactant is 40 to 60 rpm, the stirring time is 20 to 30 minutes, and/or the stirring rate after adding the metal chelating agent is 10 to 60 rpm, the stirring time is 30 to 120 minutes, and/or the stirring rate after adding the caustic soda flakes is 30 to 60 rpm, and the stirring time is 5 to 20 minutes.
  8. 8. The preparation method according to claim 6, wherein the metal chelating agent is added, stirred uniformly, heated to 40-50 ℃, and then the caustic soda flakes are added in proportion.
  9. 9. Use of the non-acid type composite plugging removing agent according to any one of claims 1 to 5 in plugging removal of an oilfield produced reservoir, the non-acid type composite plugging removing agent being prepared by the preparation method according to any one of claims 6 to 8.
  10. 10. The use according to claim 9, wherein the non-acid type composite plugging remover is used after being diluted with water to a solution with a mass concentration of 20%.

Description

Non-acid type composite blocking remover and preparation method and application thereof Technical Field The invention belongs to the technical field of oilfield development and production increase blocking removal, and particularly relates to a non-acid type composite blocking remover, a preparation method and application thereof. Background At present, a plurality of domestic oil fields enter a high water content development period, and part of the oil fields gradually develop measures for improving recovery ratio, such as water shutoff profile control, alkali flooding, ternary composite flooding, carbon dioxide flooding, air foam flooding, surfactant flooding and the like. These measures often require the addition of organic, inorganic agents, or the changing of physical and chemical conditions in the well, which may lead to scaling of the oil well, and the high mineralization of formation water exacerbates the scaling of the oil well. The current blocking removal technology mainly includes blocking removal technology and chemical blocking removal technology, wherein chemical blocking removal technology is more commonly used. The chemical blocking removing technology is to degrade and dissolve the components such as greasy dirt, polymer, inorganic matters and the like in the blocking material by utilizing the chemical characteristics of the medicament, so as to achieve the purpose of blocking removing, such as an aerobic blocking removing system, a surfactant viscosity reducing system, an acid blocking removing system, a thermochemical blocking removing system, a composite blocking removing system and the like. The chemical blocking removing technology has higher pertinence, and the precondition of the chemical agent descaling is that the composition of the scale, the scale forming position, the scale forming degree and the like must be defined, and then the type and the dosage of the chemical agent are selected. In the chemical blocking removing technology, an acid blocking removing system is generally selected, and the acid blocking removing system is used for removing scales, but the acid blocking removing agent has the following problems of low scale removing speed and low scale dissolving rate, and inorganic acid or organic acid such as hydrochloric acid, nitric acid, hydrofluoric acid and the like react fiercely in the process of removing scales, so that the phenomenon of blocking pipes caused by scale flaking and falling occurs, and the acid washing effect can also cause corrosion damage to equipment materials. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a non-acid type composite blocking remover, a preparation method and application thereof, wherein the non-acid type composite blocking remover can replace the acidizing descaling and yield increasing measures of a water injection well, has the advantages of high descaling speed and low concentration scale dissolving capacity, and can achieve the descaling rate of more than 98% on an oil well. In order to achieve the above object, the present invention provides the following technical solutions: The non-acid type composite blocking remover comprises, by weight, 1-4wt% of a non-ionic surfactant, 0.5-3wt% of an anionic surfactant, 0.5-3wt% of a metal chelating agent, 0.5-2wt% of caustic soda flakes, 2-6wt% of sodium carbonate and the balance of water. Further, the nonionic surfactant comprises one or more than two of laurylamine polyoxyethylene ether, octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, glyceride and sorbitol ester. Further, the anionic surfactant comprises one or more than two of sodium dodecyl benzene sulfonate, sodium lauryl sulfate, fatty alcohol polyoxyethylene ether sulfate and alkyl alcohol polyoxyethylene ether phosphate. Further, the metal chelating agent comprises one or more than two of tetra sodium ethylenediamine tetraacetate, amine citrate, pentasodium diethylenetriamine pentaacetate and sodium ethylenediamine tetraacetate. Further, the pH value of the non-acid type composite blocking remover ranges from 10 to 12.5. In addition, the invention also provides a preparation method of the non-acid composite blocking remover, which comprises the following steps: Mixing nonionic surfactant and water in proportion, stirring uniformly, continuously adding anionic surfactant in proportion, stirring uniformly, adding metal chelating agent in proportion, stirring uniformly, adding caustic soda flakes in proportion, stirring uniformly, adding sodium carbonate in proportion, and stirring until completely dissolving to obtain the non-acid composite blocking remover. Further, the stirring speed of the nonionic surfactant and water after mixing is 30-60 turns/min, the stirring time is 20-60 min, and/or the stirring speed of the anionic surfactant after adding is 40-60 turns/min, the stirring time is 20-30 min, and/or the