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

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 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 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 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.