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CN-121993090-A - Water injection well profile control method based on protection of low permeability layer and application thereof

CN121993090ACN 121993090 ACN121993090 ACN 121993090ACN-121993090-A

Abstract

The invention relates to a water injection well profile control method based on a protective low-permeability layer and application thereof, wherein the water injection well profile control method comprises the following steps of temporarily blocking the medium low-permeability layer by using a temporary blocking agent; the second section plug is used for blocking the high-permeability layer by using a gel profile control agent, the third section plug is used for enabling a system which is injected into the high-permeability layer in the early stage to be moved to the deep part of an oil reservoir by using a displacement section plug to realize deep profile control, and the fourth section plug is used for blocking the low-permeability layer by using a blocking remover. The method has the characteristics of simple synthesis process, no byproducts, high viscosity and shearing resistance, and also has excellent fluidity and injectability, and the viscosity retention rate of the profile control system prepared by the profile control method can still reach above 92 percent after the shearing of a pump, a pipeline and a stratum is simulated, and the breakthrough pressure reaches 8-11MPa. Thereby playing the roles of high-permeability blocking and medium-low-permeability oil displacement.

Inventors

  • DU JIE
  • Hu Xiaodie
  • XIE HUI
  • TANG KE
  • XIE LEI
  • YUAN FENGGANG
  • LI KAI
  • SUN PENGCHAO
  • LIU JIAXING
  • ZHAO YONG

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (13)

  1. 1. The water injection well profile control method based on the protection low permeability layer is characterized by comprising the following steps of: The first section plug is used for temporarily plugging the middle-low permeability layer by using a temporary plugging agent solution; The second section plug is used for blocking the hypertonic layer by using a gel profile control agent, wherein the gel profile control agent comprises a polymer, a cross-linking agent and an auxiliary agent; the system of injecting the hypertonic layer in the early stage is moved to the deep part of the oil reservoir by using the displacement slug to realize deep profile control; And (4) blocking the low-permeability layer by using a blocking remover solution.
  2. 2. The method for profile control of a water injection well based on a protective hypotonic layer according to claim 1, wherein the temporary plugging agent solution comprises one or more of CQKL-1 type pre-crosslinked gel particles and SAK-3 (II) type pre-crosslinked gel particles.
  3. 3. The water injection well profile control method based on the low permeability layer according to claim 2, wherein the mass concentration of CQKL-1 type pre-crosslinked gel particles in a temporary plugging agent solution is 0.3-0.5%, and the mass concentration of SAK-3 (II) type pre-crosslinked gel particles is 0.3-0.5%.
  4. 4. The method for profile control of a water injection well based on a low permeability layer according to claim 1, wherein the gel profile control agent comprises, by mass, 0.4-0.6% of a polymer, 0.4-0.6% of a cross-linking agent, 0.3-0.5% of an auxiliary agent and the balance of water.
  5. 5. The method for profile control of a water injection well based on a protective hypotonic layer according to claim 1 or 4, wherein the polymer comprises anionic polyacrylamide and/or derivatives thereof; the cross-linking agent comprises phenol, formaldehyde, phenolic prepolymer and/or derivatives thereof; The auxiliary agent is thiourea.
  6. 6. The water injection well profile control method based on the protective hypotonic layer according to claim 1 or 4, wherein the polymer is one or more of ureido anionic polyacrylamide, benzyl imidazole ionic liquid modified anionic polyacrylamide and crown ether grafted modified anionic polyacrylamide; The cross-linking agent consists of one or more of phenol, formaldehyde, phenolic prepolymer and urotropine; The auxiliary agent is thiourea.
  7. 7. The profile control method for a water injection well based on a protective hypotonic layer according to claim 6, wherein the ureido anionic polyacrylamide is composed of one or more of di-tert-butyl dicarbonate, o-nitrophenyl isocyanate, hydrazine hydrate, trifluoroacetic acid and di (N-succinimidyl) sebacate and has a triple helix structure; the benzyl imidazole ionic liquid modified anion polyacrylamide is prepared by Friedel-Crafts alkylation reaction of benzyl imidazole ionic liquid and polyacrylamide; The crown ether grafted modified anionic polyacrylamide is composed of one or more of dibenzo-18-crown-6, 4-formyl dibenzo-18-crown-6, polyvinyl alcohol and polyacrylamide and is in a core-shell structure.
  8. 8. The method for profile control of a water injection well based on a low permeability layer according to claim 7, wherein the benzyl imidazole ionic liquid modified anion polyacrylamide is composed of one or more of 1-butyl-3-methylimidazole bromide ionic liquid, 1-vinyl-3- (pentafluorobenzyl) imidazole bromide ionic liquid, polyacrylamide, benzoate and triphenylmethane, and has a tubular structure.
  9. 9. The water injection well profile control method based on the low permeability layer of claim 1, wherein in the third section plug, the displacement section plug is consistent with the first section plug, namely the displacement solution is one or more of BPPG and DPPG.
  10. 10. The method for profile control of a water injection well based on a low permeability layer as claimed in claim 9, wherein the mass concentration of BPPG in the displacement solution is 0.3-0.5%, and the mass concentration of DPPG is 0.3-0.5%.
  11. 11. The method for profile control of a water injection well based on a low permeability layer according to claim 1, wherein the blocking remover is one or more of ammonium persulfate and acetic acid depolymerizing agent.
  12. 12. The method for profile control of a water injection well based on a low permeability layer according to claim 11, wherein the mass concentration of the acetic acid depolymerizing agent in the plugging removing agent solution is 8-12%, and the mass concentration of ammonium persulfate is 35-48%.
  13. 13. The application of the water injection well profile control method based on the low permeability layer protection according to any one of claims 1 to 12, which is characterized in that the water injection well profile control method is suitable for a heterogeneous oil reservoir with a permeability variation coefficient of more than 0.5.

Description

Water injection well profile control method based on protection of low permeability layer and application thereof Technical Field The invention relates to the technical field of oil and gas field development, in particular to a water injection well profile control method based on a protective hypotonic layer. Background The oil field enters the development stage of 'double high' (namely, high yield peak and high recovery ratio), the extraction degree is low, the comprehensive water content is high, the oil extraction speed is slow, and deep profile control measures are required to be developed due to long-term water injection and water channeling development. Conventional general profile control generally enables the profile control agent to enter the high-permeability layer and simultaneously causes part of the profile control agent to enter the low-permeability layer so as to pollute the low-permeability layer. If the injection speed of the profile control agent is reduced, the injection pressure is too high, so that the profile control agent enters the low-permeability layer and a crosslinking reaction occurs in the low-permeability layer, which not only affects the profile control effect, but also is not beneficial to subsequent water-flooding oil increase. In the prior art, as disclosed in publication No. CN102311728B, a chemical depressurization and injection-increasing agent for a water injection well is provided, and the main components comprise cetyl trimethyl ammonium bromide, MY/IMC-80BHH corrosion inhibitor, polyamino polyether methylene phosphonic acid, polyquaternium, citric acid (industrial product) and hydrochloric acid (industrial product), wherein the chemical depressurization and injection-increasing agent is uniformly added into the injected water, and the purposes of reducing pressure and increasing injection of the water injection well of a low-permeability oilfield are achieved by reducing the interfacial tension of oil and water, improving the permeability of an aqueous phase and the migration speed of an oil-water microemulsion, preventing the formation of scale and inhibiting the growth of various bacteria. CN117659972a discloses a preparation method and application of a cross-sectional plugging water-sealing channeling agent for corncob particle powder. The main components of the profile control plugging water channeling agent comprise corncob particle powder, liquid water glass and a surfactant. Under the stirring condition, the corncob particle powder is uniformly dispersed in the water glass solution containing the surfactant, micropores in the corncob particles and the surfaces of the micropores are fully immersed by the water glass solution under the action of the surfactant in the stirring and dispersing process, so that the specific gravity of the particles is changed, and the corncob particle powder profile control plugging water channeling agent can be stably suspended in the solution. The profile control, plugging and water sealing channeling agent is prepared by using injected water to prepare proper concentration, and can realize profile control and water plugging of a water-flooding oil reservoir by matching different activation processes, and CN116444722B discloses a high-molecular polyacrylamide emulsion water plugging profile control agent and a preparation method thereof. The preparation method comprises the steps of introducing nitrogen into a reaction kettle, sequentially adding acrylamide, vinyltriethoxysilane, 2-amino-2-methyl-4-pentenoic acid, 1-vinyl-3-benzylimidazole bromide, N-methylenebisacrylamide, an emulsifying agent, a dispersing agent, buffer salt and deionized water, stirring to obtain uniform emulsion, adding an initiator into a high-position dropwise adding groove, slowly dropwise adding the initiator into the reaction kettle, automatically heating the solution in the dropwise adding process, and after dropwise adding, carrying out heat preservation reaction and cooling to below 40 ℃ to obtain the water shutoff profile control agent. In summary, the existing profile control agent synthesis technology is complex in synthesis process, more in generated byproducts, not only needs to purify components, but also needs to spend a great deal of time and cost, and the conventional profile control agent used on site is poor in temperature resistance, acid and alkali resistance and shearing resistance, so that the plugging performance of the profile control agent after entering a stratum is poor, and the low permeability layer is not considered to be protected, so that pollution to a non-target profile control layer is easily caused. Disclosure of Invention The invention aims to provide a water injection well profile control method based on a protective hypotonic layer, which solves the problems that ① is complex in synthesis process and more in generated byproducts in the existing profile control agent synthesis technology, ② is required to purify componen