Abstract: A low density, high-strength, degradable temporary plugging agent which includes 60% by weight to 85% by weight of polylactic acid, 5% by weight to 20% by weight of a starch, 5% by weight to 10% by weight of polycaprolactone, 2% by weight to 5% by weight of a solubilizing agent, and 2% by weight to 5% by weight of a toughening agent, based on 100% by weight of the total weight of the agent. The rigid agent can result in bridge plugging in existing cracks, with a significant increase in pressure. The preparation method is simple, the process requirements are low, and industrial production can be realized. When applied to temporary plugging fracturing, under formation conditions, it can be completely degraded within a certain period of time and will not cause secondary damage to the reservoir, while preventing the agent from polluting the formation and the occurrence of pump accidents.

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: A surfactant that changes the wettability of tight sandstone and its preparation method and application. By adding the aqueous phase solution into the oil phase solution, and under the action of the emulsifier, a uniformly dispersed phase is achieved. Then adding initiator, stirring and raising the temperature, reacting the reaction at the temperature to obtain a colorless and transparent liquid, i.e., high polymer. At room temperature, adding fluorocarbon surfactant and biosurfactant and stirring was continued for 4 hours to obtain a surfactant that changes the surface wettability of tight sandstone. The surfactant of the present invention can reduce the oil-water interfacial tension, transform the oil-wet surface into water-wet surface, which reduces the adhesion of oil droplets to rock surface and improves the flowability of crude oil in the original stratum, and improves the recovery of low-permeability reservoir.

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: A low density, high-strength, degradable temporary plugging agent which includes 60% by weight to 85% by weight of polylactic acid, 5% by weight to 20% by weight of a starch, 5% by weight to 10% by weight of polycaprolactone, 2% by weight to 5% by weight of a solubilizing agent, and 2% by weight to 5% by weight of a toughening agent, based on 100% by weight of the total weight of the agent. The rigid agent can result in bridge plugging in existing cracks, with a significant increase in pressure. The preparation method is simple, the process requirements are low, and industrial production can be realized. When applied to temporary plugging fracturing, under formation conditions, it can be completely degraded within a certain period of time and will not cause secondary damage to the reservoir, while preventing the agent from polluting the formation and the occurrence of pump accidents.

Abstract: A surfactant that changes the wettability of tight sandstone and its preparation method and application. By adding the aqueous phase solution into the oil phase solution, and under the action of the emulsifier, a uniformly dispersed phase is achieved. Then adding initiator, stirring and raising the temperature, reacting the reaction at the temperature to obtain a colorless and transparent liquid, i.e., high polymer. At room temperature, adding fluorocarbon surfactant and biosurfactant and stirring was continued for 4 hours to obtain a surfactant that changes the surface wettability of tight sandstone. The surfactant of the present invention can reduce the oil-water interfacial tension, transform the oil-wet surface into water-wet surface, which reduces the adhesion of oil droplets to rock surface and improves the flowability of crude oil in the original stratum, and improves the recovery of low-permeability reservoir.

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: Embodiments of the present invention provide a chelating agent and its preparation method and use. The chelating agent is prepared from the following raw materials in weight percent with respect to 100% of the total weight of the prepared chelating agent: 15% to 30% of an iron ion stabilizing agent, 5% to 12% of dichloroethane, 10% to 20% of ethanol solution, 10% to 20% of sodium hydroxide, 5% to 10% of carbon disulfide, 1.5% to 4.5% of an adjuster, and water as balance. The raw materials for the chelating agent according to the present invention are widely available from a variety of sources, and are less expensive. The chelating agent according to the present invention has a stable performance and a long lifetime, can be stored and use for a long time, and is highly compatible with acidizing acid liquid systems.

Abstract: An intelligent test system and a method for a multi-segment fractured horizontal well. The intelligent test method for a multi-segment fractured horizontal well comprises: step A: placing a test tubular column into an underground horizontal section; step B: setting a pressure building packer and a hanging packer by means of pressurization after the test tubular column is placed into an underground designed position; step C: breaking a hydraulic release connector to separate the hydraulic release connector from a seal pipe; step D: pulling out a first oil pipe, and reserving the tubular column comprising the seal pipe and located on the downstream part of the seal pipe in a horizontal well; and step E: placing a production tubular column or a communications tubular column into a vertical section of the horizontal well.

Abstract: Disclosed are an intelligent test system and method for a multi-segment fractured horizontal well. The intelligent test method for a multi-segment fractured horizontal well comprises: step A: placing a test tubular column into an underground horizontal section; step B: setting a pressure building packer and a hanging packer by means of pressurization after the test tubular column is placed into an underground designed position; step C: breaking a hydraulic release connector to separate the hydraulic release connector from a seal pipe; step D: pulling out a first oil pipe, and reserving the tubular column comprising the seal pipe and located on the downstream part of the seal pipe in a horizontal well; and step E: placing a production tubular column or a communications tubular column into a vertical section of the horizontal well.