Abstract: An injection stimulation agent for water injection well and the preparation method and application thereof are described. The raw material composition of the injection stimulation agent for water injection well comprises: 5.0%-10.0% of sulfamic acid, 10.0%-20.0% of methanol, 10.0%-20.0% of tartaric acid, 10.0%-20.0% of ethylenediamine tetramethylene phosphoric acid, 5.0%-10.0% of sodium polyacrylate, 5.0%-8.0% of cocoyl hydroxyethyl sulfonic acid and the balance of water. Embodiments include a preparation method of the above injection stimulation agent. The injection stimulation agent for water injection well can be used in acidizing treatment process of the reservoir, and can be used directly. The injection stimulation agent can play the role of shrinking swelled clay at the same time of dissolving scale, and finally achieve the purpose of depressurization and enhanced production.

Abstract: On-line diverting acids for continuous injection into water injection wells and methods of preparing the diverting acid are disclosed. The on-line diverting acids have a raw material composition of: 5.0-25.0% of hydrochloric acid, 3.0%-6.0% of ammonium fluoride, 4.0%-8.0% of a diverting agent, 3.0%-7.0% of a chelating agent, 1.0-3.0% of a corrosion inhibitor, 1.0-3.0% of an anti-swelling/swelled-clay-shrinking agent and a balance of water. The on-line diverting acids can remove plugging from deep zones of high and low permeability layers, and can be continuously injected to simplify the construction process, to achieve the purpose of reducing the pressure and stimulating the injection.

Abstract: A chelating agent may be used for reservoir acidification and stimulating injection. The raw material composition of the chelating agent comprises: 10.0%-20.0% of methanesulfonic acid, 10.0%-20.0% of methanol, 10.0%-20.0% of polyaspartic acid, 10.0%-15.0% of epoxy succinic acid, 5.0%-10.0% of sodium cetyl sulfonate, 10.0%-15.0% of cetyltrimethylammonium bromide and the balance of water. The present disclosure also provides a preparation method of the above chelating agent. The chelating agent for reservoir acidification and stimulating injection may be used in an acidizing and stimulating injection process, wherein it can effectively dissolve rock cracks, be used directly without need to be reversed.

Abstract: The present disclosure provides a pressure-reducing and injection-enhancing anti-scaling agent for low-permeability water-injection wells and a preparation method thereof. The anti-scaling agent is prepared from starting materials comprising: 10 to 12 parts of non-ionic surfactant(s), 18 to 20 parts of hexasodium triethylenetetramine-N,N,N?,N?,N??,N??-hexaacetate, 5 to 8 parts of anionic surfactant(s), 6 to 8 parts of an organic phosphonic acid-carboxylic acid scale inhibitor, 2 to 5 parts of a dispersant, 15 to 18 parts of a diluent, 8 to 10 parts of an organic amine salt, and 30 to 36 parts of water. The pressure-reducing and injection-enhancing agent according to the present disclosure is characterized by having multiple functions in one agent. When used in an amount being 0.5% of the water injected to a water injection well, it shows excellent anti-swelling property, shrinking property, anti-corrosive property, and calcium sulfate and barium (strontium) sulfate scale resistance.

Abstract: The present invention provides a chelating agent for reservoir acidification and stimulating injection and its preparation method and application. The raw material composition of the chelating agent comprises: 10.0%-20.0% of methanesulfonic acid, 10.0%-20.0% of methanol, 10.0%-20.0% of polyaspartic acid, 10.0%-15.0% of epoxy succinic acid, 5.0%-10.0% of sodium cetyl sulfonate, 10.0%-15.0% of cetyltrimethylammonium bromide and the balance of water. The present invention also provides a preparation method of the above chelating agent. The chelating agent for reservoir acidification and stimulating injection of the invention is used in an acidizing and stimulating injection process, wherein it can effectively dissolve rock cracks, be used directly without need to be reversed.

Abstract: The present invention provides an injection stimulation agent for water injection well and the preparation method and application thereof. The raw material composition of the injection stimulation agent for water injection well comprises: 5.0%-10.0% of sulfamic acid, 10.0%-20.0% of methanol, 10.0%-20.0% of tartaric acid, 10.0%-20.0% of ethylenediamine tetramethylene phosphoric acid, 5.0%-10.0% of sodium polyacrylate, 5.0%-8.0% of cocoyl hydroxyethyl sulfonic acid and the balance of water. The present invention further provides a preparation method of the above injection stimulation agent. The injection stimulation agent for water injection well of the present invention can be used in acidizing treatment process of the reservoir, and can be used directly. The injection stimulation agent can play the role of shrinking swelled clay at the same time of dissolving scale, and finally achieve the purpose of depressurization and enhanced production.

Abstract: The present disclosure provides a diverting agent for diversion acidizing in water injection wells and a preparation method thereof. The diverting agent for diversion acidizing in water injection wells has a raw material composition including: 3%-6% of ethylenediamine, 12%-25% of bromododecane, 10%-20% of a solvent, 10%-20% of an assistant, 14%-28% of oleic acid, 5%-10% of stearic acid salt, 1%-2% of a dispersing agent and a balance of water. The present disclosure also provides a method for preparing the above-mentioned diverting agent for diversion acidizing in water injection wells. The diverting agent for diversion acidizing in water injection wells of the present disclosure can be used for temporary plugging diverting of acid solution in on-line acidification of water injection wells or in acidification operation of oil reservoir with a greater heterogeneity, which has good compatibility with the acid solution and can be used for temporary plugging of high-permeability zones.

Abstract: The present disclosure provides an on-line diverting acid for continuous injection into water injection wells and a preparation method thereof. The on-line diverting acid for continuous injection into water injection wells has a raw material composition of: 5.0-25.0% of hydrochloric acid, 3.0%-6.0% of ammonium fluoride, 4.0%-8.0% of a diverting agent, 3.0%-7.0% of a chelating agent, 1.0-3.0% of a corrosion inhibitor, 1.0-3.0% of an anti-swelling/swelled-clay-shrinking agent and a balance of water. The present disclosure also provides a preparation method of the above-mentioned on-line diverting acid. The on-line diverting acid of the present disclosure can remove plugging from deep zones of high and low permeability layers, and can be continuously injected to simplify the construction process, so as to achieve the purpose of reducing the pressure and stimulating the injection.

Abstract: The present disclosure provides a pressure-reducing and injection-enhancing anti-scaling agent for low-permeability water-injection wells and a preparation method thereof The anti-scaling agent is prepared from starting materials comprising: 10 to 12 parts of non-ionic surfactant(s), 18 to 20 parts of hexasodium triethylenetetramine-N,N,N?,N?,N??,N??-hexaacetate, 5 to 8 parts of anionic surfactant(s), 6 to 8 parts of an organic phosphonic acid-carboxylic acid scale inhibitor, 2 to 5 parts of a dispersant, 15 to 18 parts of a diluent, 8 to 10 parts of an organic amine salt, and 30 to 36 parts of water. The pressure-reducing and injection-enhancing agent according to the present disclosure is characterized by having multiple functions in one agent. When used in an amount being 0.5% of the water injected to a water injection well, it shows excellent anti-swelling property, shrinking property, anti-corrosive property, and calcium sulfate and barium (strontium) sulfate scale resistance.