30results about How to "Improved water absorption profile" patented technology

The invention relates to a plugging removal and stimulation method for a low permeability oil well. The ultra-low resistance acid-type microemulsion is prepared by the following components: 10%-25% of acid, 5%-20% of oil, 5%-25% of alcohol, 0.5%-5% of surfactant, 0.5%-3% of inorganic salt, 0.3-1.5% of corrosion inhibitor and the balance water. The method comprises the following steps: injecting the prepared microemulsion in the oil bearing reservoir of the oil well, closing the oil well to react for 4-10h, cleaning the oil well, flowing the reaction exhaust liquor back, and completing the oilwell to perform normal production. The ultra-low resistance acid-type microemulsion used by the invention has thermodynamic stability, is a high dispersive acid-type microemulsion with good solubilization capacity, has ultra-low surface and interfacial tensions and good solubilization capacity and can increase the dispersive capacity of crude in water and the emulsification and peeling function to oil film; the microemulsion also has good dissolubility in water or oil and good fluidity due to high carrying capability and low seepage resistances so that the oil yield of the oil well is increased and the water content is reduced; the liquid surface tension in oil reservoir is reduced and the flow resistance of the crude is lowered so that the mining rate of the crude is increased and the plugging removal and stimulation of the oil well can be realized.

The invention discloses a layered pulse pressure-charging plug removal device and method for an oil filed water injection well. The device is arranged onto a water injection main line, a high-pressure water injection pipeline and the water injection well. The device comprises pressure-charging boxes, a low-pressure water injection pipeline and a high-pressure water injection pipeline, wherein the pressure-charging boxes are respectively provided with a high-pressure chamber and a low-pressure chamber; a piston is arranged between the corresponding high-pressure chamber and the corresponding low-pressure chamber, and the high-pressure chamber and the low-pressure chamber are communicated with the water injection main line respectively through a first water inlet pipeline and a second water inlet pipeline; the high-pressure chambers are communicated with the high-pressure water injection pipeline through a high-pressure pipeline, and are communicated with the water injection well; the first end of the low-pressure water injection pipeline is communicated with the low-pressure chambers; the second end of the low-pressure water injection pipeline is connected with a sleeve valve of the water injection well; the high-pressure water injection pipeline, the first water inlet pipeline, the second water inlet pipeline, the high-pressure pipeline and the low-pressure water injection pipeline are respectively provided with a first retaining valve, a second retaining valve, a third retaining valve, a fourth retaining valve and a fifth retaining valve in sequence; and a pressure gage is arranged between the first retaining valve and an oil pipe valve. Pressure-charging plug removal treatment can be independently performed on a low water intake layer in the water injection well so as to improve a water injection profile.

The invention discloses a compound acid blockage removing fluid. The blockage removing fluid is prepared from raw materials in parts by weight as follows: 4-6 parts of a foam flushing fluid, 20-30 parts of a prepad fluid, 70-100 parts of main acid and 10-20 parts of postpad fluid. The acid fluid has higher capacity of removing organic sediment pollution and high acid residue and emulsifying resistance. The acid fluid has low corrosion speed and good swelling inhibition and does not change the original water wetting characteristic of the stratum.

The invention relates to a method for improving the crude oil recovery ratio by utilizing a salt sensitive self-thickening polymer. The method comprises the following steps: firstly vacuum-pumping high and low sand filling tube cores respectively and saturating formation simulated water; respectively displacing the high and low sand filling tube cores at an injection sped of 1 mL / min by using simulated salt water and determining the pore volume and the permeability; saturating dehydrated and degassed ground crude oil at an injection speed of 1 mL / min; sealing the sand filling tube cores after the crude oil is saturated and then placing for 48 hours at a constant temperature; displacing the high and low sand filling tube cores which are connected in parallel at an injection speed of 1 mL / min and calculating the water drive recovery ratio; injecting a certain volume of salt sensitive self-thickening polymer solution at an injection sped of 1 mL / min and then injecting the stimulated salt water to carry out over displacement; sealing the high and low sand filling tube cores which are connected in parallel and placing for 120 hours at a constant temperature till the crude oil is thickened. The method has the benefits that the operation is simple and convenient, the injection property is good, the formation application scope is wide, and the water injection profile of a water injection formation can be effectively improved, and the crude oil recovery ratio is improved.

The deep wood chip gel plugging agent is used in water injecting well to plug the high penetrating band in thick oil stratum to lower ineffective water circulation. The deep plugging agent consists of high molecular weight anionic polyacrylamide of molecular weight over 19 million and hydrolysis degree of 25-30 % 0.15-0.5 wt%, phenol compounded polyamine 0.1-0.3 wt%, resorcinol 0.01-0.02 wt%, oxalic acid 0.1-0.2 wt%, wood chip 0.5-2.5 wt% and water 96.48-99.14 wt%, which are compounded into water solution of 0.86-3.52 wt% water solution. The present invention has low use concentration, controllable gel forming time and viscosity, low cost and simple compounding process.

The invention discloses a method for increasing oil recovery of heavy oil reservoirs through a composite heat carrier, and particularly relates to a method for increasing oil recovery of heavy oil reservoirs through a composite heat carrier composed of hot water, a gas and a chemical agent. According to the method, crude oil recovery is increased, by injecting hot water and flue gas generated by boiler burning together into an oil layer, and by injecting a foaming agent by means of slug injection. The method includes the steps of a, injecting a mixture of hot water and flue gas 0.15-0.2 times the pore volume of a formation; b, injecting foaming agent solution into a water injection well for 25-30 d; c, injecting the hot water and flue gas mixture for 60-80 d; d, repeating the steps b and c. Water (vapor) can be effectively blocked from channeling, vapor wave and volume are increased, heavy oil recovery is substantially increased, and as the flue gas generated by burning is injected directly underground, heat efficiency can be improved and environmental pollution can also be reduced.

The invention discloses a chitosan cross-linked and modified acrylamide compound as well as a preparation method thereof and application thereof, and belongs to the field of oilfield chemistry. The preparation method for the chitosan cross-linked and modified acrylamide compound comprises the following steps: 1) at a temperature being 50-70 DEG C, completely dissolving 0.04-0.12g of a biological type cross-linking agent chitosan into 50 mL of acid, adding 0.05-0.25g of an initiator, adding 50 mL of a solution with 6-8.5g of the acrylamide after certain time, and carrying out free radical polymerization reaction at certain stirring speed, thereby synthesizing a first product; and putting a product obtained in the step 1) at a temperature being 90-110 DEG C to carry out nucleophilic reaction, thereby obtaining polymer gel. The gel prepared by the preparation method is economical and environmental-friendly, has a cross-linked net-shaped structure, further has good shearing resistance, temperature and salt resistance, and can be used as a gel profile control agent.

The invention relates to a modifying and flooding agent for reutilization of residual polymers in a formation and an application thereof. The modifying and flooding agent for the reutilization of the residual polymers in the formation consists of 0.8-2.0% of aqueous medium dispersing type polyacrylamide and formation water. The modifying and flooding agent, provided by the invention, has the advantages of simplicity in system constitution, environment friendliness, short dissolving time, simple construction process, few utilized devices and suitability in field use of offshore polymer flooding. According to the modifying and flooding agent for the reutilization of the residual polymers in the formation, a flocculation system can be formed in the polymer flooding process and the subsequent water driving process by utilizing the residual polymers in the formation so as to effectively block a high-permeability channel, so that the modifying and flooding agent has capacities for delaying the penetration of polymer solution in the formation and improving a conformance factor, and the recovery efficiency of crude oil is improved, and the concentrations of the produced polymers are lowered.

The invention provides a high-temperature-resistant high-strength underground cross-linked gel profile control agent. The profile control agent is prepared from the following raw materials in percentage by mass: 3 to 8 percent of acrylamide, 0.1 to 1.0 percent of 2-acrylamido-2-methylpropanesulfonic acid, 1 to 5 percent of Na-montmorillonite, 0.01 to 0.1 percent of cross-linking agent, 0.01 to 0.1percent of initiator, 0.1 to 0.5 percent of pH regulator and the balance of water. The underground cross-linked gel profile control agent has good injection performance and sweep performance, can improve the plugging capacity and plugging effect of the plugging agent on strata, has the advantages of simple preparation process and good injection performance, and can be used for deep plugging of high-temperature oil reservoirs.

On one hand, the invention discloses a modifying and flooding agent suitable for a high-temperature and high-salt heavy oil reservoir, the modifying and flooding agent is prepared from the following components in percentage by mass: 0.2-0.5% of a polymer, 0.01-0.1% of a cross-linking agent, 0.2-0.8% of a stabilizer and the balance of water, and the polymer is AM / AMPS or AM / NVP / AMPS. The invention further discloses a preparation method of the modifying and flooding agent suitable for the high-temperature and high-salt heavy oil reservoir. The modifying and flooding agent suitable for the high-temperature and high-salt heavy oil reservoir has high viscosity, the crosslinking strength is 800-1200 mPa.s, the viscosity of injected water can be greatly improved, long-term stability can be kept under the high-temperature and high-salt conditions, the water absorption profile can be effectively improved, the problem of water channeling of the injected water is solved, and the water-oil displacement effect under the high-temperature and high-salt oil reservoir condition is improved, so that the heavy oil recovery rate is increased.

The invention discloses a method for calculating the processing radius of a plug removal and augmented injection agent. The problem that the design processing radius of the unblocking and augmented injection agent is uncertain is solved. According to the technical scheme, an unstable seepage model of a specific layer section of a water injection well is combined with a water injection layer heat transfer model, and the relation between the water injection well water absorption profile and the temperature gradient is obtained; temperature and depth data obtained through well logging are substituted into the relation between the water absorption profile and the temperature gradient, data of the water absorption profile are obtained, and the water absorption difference of the specific interval can be obtained according to the data of the water absorption profile; and the processing radius of the plug removal and injection enhancement agent is calculated according to the water absorption difference. According to the method for calculating the processing radius of the plug removal and augmented injection agent, the calculation result is more reliable and better conforms to the field reality, the effect of improving the water injection profile of the water injection well can be improved, and finally the oil field recovery efficiency is improved.

The invention provides a low-temperature and high-salinity organic water shutoff gel for oil reservoirs, which is composed of the following substances in percentage by mass: 0.2-0.5% of main agent, wherein anionic polyacrylamide is selected, the weight-average molecular mass is 18*10<6>-24*10<6>, and the hydrolysis degree is 18-23%; 0.2-0.4% of a cross-linking agent, which a phenolic resin cross-linking agent is selected, and the content of hydroxymethyl is 28.49%-45.28%; 0.05-0.2% of an accelerant which is selected from hydroquinone or resorcinol; 0.03-0.1% of a conditioning agent, wherein hydrochloric acid or oxalic acid is selected; 0.05-0.15% of a stabilizing agent, wherein thiourea is selected; and the balance water. The gel forming time of the water plugging gel is adjustable, the formed gel is high in strength, good in salt tolerance and good in stability, the plugging rate of a rock core reaches 93% or above, and the requirements of oil reservoirs can be met.

The invention relates to slow cross-linking jelly for profile control of medium-high temperature oil reservoirs and a preparation method of the slow cross-linking gel. The gel comprises the following components in percentage by mass: 0.4%-1.0% of a main agent, 0.2%-1.0% of a cross-linking agent, 0.05%-0.2% of a catalyst, 0.3%-1.0% of a stabilizer, 0.025%-0.1% of an accelerant and the balance of water, and the sum of the components is 100%. The main agent is an acrylamide / 2-acrylamide-2-methylpropanesulfonic acid (AM-AMPS) copolymer, the cross-linking agent is melamino-formaldehyde resin, the catalyst is ammonium chloride, the stabilizer is acidic silica sol, and the accelerant is hydroquinone. The slow crosslinking gel for profile control of the medium-high temperature oil reservoir is suitable for water shutoff and profile control of an oil layer with the temperature of 90-110 DEG C and the mineralization degree of 1.0*10<5>-4.0*10<5> mg / L, the gel forming time is controllable within 72-168 hours, and the formed gel is high in strength, can reach the G-I level, is good in stability and can meet the requirements of deep profile control field operation.

The invention provides a method for improving a water absorption profile by combining profile control and acidification, the method comprises the following steps: firstly, injecting a flexible gel particle slug into an oil layer perforation section for profile control and plugging of dominant large pore channels, and then injecting a retarded acid into the oil layer perforation section for acidizing a low-permeability layer section. Flexible gel particles are used for profile control and plugging of the dominant water flow large pore channels of an oil layer so as to realize the liquid flow diversion of a subsequent injection medium. On this basis, the injected retarded acid acidizes a low-permeability layer is not affected or relatively weakly affected by water drive, the respective advantages of the flexible gel particles for plugging the large pore channels and the retarded acid for acidizing the low-permeability layer are fully brought into play to improve the water absorption profile in combination. The method has the advantages the acid liquor is prevented from reacting with a water layer or the dominant water flow channels and fully reacts in the low-permeability layer, theineffective action of the acid is reduced, and the water absorption profile is effectively improved.

The invention provides a clear water-sewage mixed profile control agent. The clear water-sewage mixed profile control agent comprises a water-based profile control and water shutoff, solid particles, polyacrylamide, a cross-linking agent and a conditioning agent in a mass ratio of (5-10):(0.5-1.0):(0.1-0.5):(1.0-2.0):(0.1-0.2). The invention also provides the application of the clear water-sewage mixed profile control agent. The clear water-sewage mixed profile control agent provided by the invention has good water shut-off and profile control performance, can improve the water injection profiles of water injection wells, prevents unreasonable water channeling along fracture direction and flooding, and realizes efficient and high efficiency water injection, thereby reaching the purposes of improving the reservoir use degree and oil displacement efficiency.

The invention provides an oil-water well linkage profile control method. The oil-water well linkage profile control method comprises the steps that a target water well and a target oil well communicated with the target water well are selected as a profile control well group; and profile control operation is carried out on the target water well, meanwhile, oil well linkage operation is carried out on the target oil well, and the oil well linkage operation comprises one or more of water plugging operation, oil extraction operation, reservoir transformation operation and sand prevention operation. The oil-water well linkage comprehensive treatment technology is implemented on oil-water wells with good reservoir stratum corresponding relations, oil-water well measures are implemented at the same time, the oil-water wells conduct production in a coordinated mode, the problem that remaining oil between the oil-water wells cannot be effectively used is solved, water well water absorption profiles and oil well liquid production profiles are effectively improved, the water injection swept area is increased, and the production efficiency is improved. And the recovery efficiency of the oil well is improved.

The invention discloses an oil well temporary blocking acidizing measurement technological system. The oil well temporary blocking acidizing measurement technological system comprises four parts which comprise an acid storage system, a water storage system, a pumping system and a guiding delivering system. The acid storage system and the water storage system are connected to the pumping system through the guiding delivering system, any passageway can be closed in necessity, the pumping system is connected to a wellhead, and thus the whole acidizing measurement system is formed. Each system comprises various novel devices so as to be differentiated from other similar acidizing systems. The series of problems that the permeability max-min ratio is large, acidizing block removal on a low-permeability layer is difficult, and water exudation is serious after acidizing can be effectively solved; blocking of a large-thickness layer or a longitudinal heterogeneous layer can be effectively removed, and the liquid production section can also be recovered and improved; through the technology, contradiction between water injection well layers can be relieved, the hydrophilic section is improved, and the water flooding thickness is increased; and construction is convenient, cost is low, and a reservoir stratum is not damaged.

The deep wood chip gel plugging agent is used in water injecting well to plug the high penetrating band in thick oil stratum to lower ineffective water circulation. The deep plugging agent consists of high molecular weight anionic polyacrylamide of molecular weight over 19 million and hydrolysis degree of 25-30 % 0.15-0.5 wt%, phenol compounded polyamine 0.1-0.3 wt%, resorcinol 0.01-0.02 wt%, oxalic acid 0.1-0.2 wt%, wood chip 0.5-2.5 wt% and water 96.48-99.14 wt%, which are compounded into water solution of 0.86-3.52 wt% water solution. The present invention has low use concentration, controllable gel forming time and viscosity, low cost and simple compounding process.

The invention discloses a self-selective diversion plug-removing system for improving the contradiction between sandstone reservoir layers and an application method thereof. The self-selective diversion blocking removal system comprises 20-30 parts by weight of a multifunctional self-selecting diversion blocking removal agent, 60-70 parts by weight of a composite plugging removal agent, 3-5 parts by weight of an ion stabilizer, 3-5 parts by weight of a Clay stabilizer, the rest is water. Among them, the multifunctional self-selective diverting and blocking removing agent includes modified betaine-type amphoteric surfactant, fluorocarbon surfactant, methylsilane, triethanolamine and aldehyde-ketone condensate. The invention is applied to acidizing and plugging removal of water injection wells, and is especially suitable for sandstone reservoirs with prominent contradiction between layers. The construction is convenient, safe, and the measures are stable.

The invention discloses a layered pulse pressure-charging plug removal device and method for an oil filed water injection well. The device is arranged onto a water injection main line, a high-pressure water injection pipeline and the water injection well. The device comprises pressure-charging boxes, a low-pressure water injection pipeline and a high-pressure water injection pipeline, wherein the pressure-charging boxes are respectively provided with a high-pressure chamber and a low-pressure chamber; a piston is arranged between the corresponding high-pressure chamber and the corresponding low-pressure chamber, and the high-pressure chamber and the low-pressure chamber are communicated with the water injection main line respectively through a first water inlet pipeline and a second water inlet pipeline; the high-pressure chambers are communicated with the high-pressure water injection pipeline through a high-pressure pipeline, and are communicated with the water injection well; the first end of the low-pressure water injection pipeline is communicated with the low-pressure chambers; the second end of the low-pressure water injection pipeline is connected with a sleeve valve of the water injection well; the high-pressure water injection pipeline, the first water inlet pipeline, the second water inlet pipeline, the high-pressure pipeline and the low-pressure water injection pipeline are respectively provided with a first retaining valve, a second retaining valve, a third retaining valve, a fourth retaining valve and a fifth retaining valve in sequence; and a pressure gage is arranged between the first retaining valve and an oil pipe valve. Pressure-charging plug removal treatment can be independently performed on a low water intake layer in the water injection well so as to improve a water injection profile.

The invention belongs to the technical field of reservoir diversion acidification construction, and particularly relates to a mineralization degree sensitive diversion temporary plugging agent and a preparation method and application thereof. The mineralization degree sensitive type diversion temporary plugging agent is prepared from the following raw materials: 20.0-25.0 percent of olefin sulfonic acid, 10.0-20.0 percent of sodium octylsulfate, 3.0-5.0 percent of sodium alkyl sulfate, 20.0-25.0 percent of methanol and the balance of water. The mineralization degree sensitive diversion temporary plugging agent is used in a reservoir diversion acidification construction process. In the acidification process of the mineralization degree sensitive type diversion temporary plugging agent, whenthe concentration of calcium ions generated in the reaction process of an acid liquid and a stratum is increased to 2% or above, micelles of 5-200 microns are formed, the stratum high-permeability layer can be plugged, the acid liquid is promoted to turn to a low-permeability reservoir to be transformed, and the water injection profile is improved; after acidification is finished and water injection is recovered, the formed micelles can be rapidly dissolved in water, and finally the purposes of pressure reduction and yield increase are achieved.

The present invention relates to polymer flooding method in oil field, and is especially polymer flooding method for secondary oil layer. The method is to inject polymer solution of polyacrylamide of molecular weight 8,000-19,000 KD and concentration 600-1200 mg / L into secondary oil layer. The polymer solution is compounded through mixing polymer with clear water via stirring. The present invention has the beneficial effect of lowering the relative water injectivity, lowering the water content and raising the oil recovering rate from secondary oil layer.

The intelligent environment-friendly profile control agent comprises a curing agent, a toughening agent, a dispersing agent, a high-molecular polymer, an organic composite resin cross-linking agent A and an organic composite resin cross-linking agent B. The organic composite resin cross-linking agent A is a profile control (flooding) cross-linking agent A for oil extraction, the molecular formula of the profile control (flooding) cross-linking agent A for oil extraction is C7H8O, and the molecular formula of the profile control (flooding) cross-linking agent B for oil extraction is C7H8O. The organic composite resin (flooding) cross-linking agent B is a profile control (flooding) cross-linking agent B for oil extraction, the molecular formula of the profile control (flooding) cross-linking agent B for oil extraction is CH4N2S, and the high-molecular polymer is polyacrylamide. According to the intelligent environment-friendly profile control agent applied to the oil field water well, a gel system of a high-strength three-dimensional space net-shaped structure is formed, the water absorption profile of a water injection well can be effectively improved, and then the purpose of changing the liquid production profile of a communicated oil well is achieved; the profile control agent is suitable for profile control, flooding and plugging of water flooding and polymer flooding blocks.

The invention discloses a preparation method of a supramolecular water plugging agent for improving a water-intake profile of an oil pool. The preparation method of the supramolecular water plugging agent for improving the water-intake profile of the oil pool comprises a mass fraction formula and a making method, wherein the mass fraction formula is that the ratio of modified phenolic resin to a polymer to a hydroxyl compound to a high-price metal salt to water is equal to (0.05 to 0.3): (0.005 to 0.08): (10 to 20): (0.2 to 0.8): (80 to 90); according to the formula, a supporting agent modified polyacrylamide is added into the water in a certain proportion, an obtained mixture is uniformly agitated, and then the hydroxyl compound is added into the agitated obtained mixture, and a newly obtained mixture is uniformly agitated. Afterwards, the modified phenolic resin is added into the newly obtained mixture, subsequently, a conditioning agent high-price metal salt is added into a finally obtained mixture, and an obtained product is mixed. The preparation method of the supramolecular water plugging agent for improving the water-intake profile of the oil pool has the advantages that a system having viscoelasticity and particle property at the same time can be formed; the supramolecular water plugging agent has favorable chemical stability and heat stability, and is resistant to a temperature up to 90 DEG C. The supramolecular water plugging agent has the characteristics of low viscosity, good pumpability, good injectivity, simple site operation, safety and reliability, and can dynamically penetrate into the deep part of the oil pool for carrying out plugging, so as to improve the water-intake profile of the oil pool, and to achieve the purpose of changing the direction of a liquid flow.