34results about How to "Lower mobility ratio" patented technology

The invention discloses a low-tension viscosity-reducing oil displacement agent, which is used for common heavy oil reservoirs, has a good viscosity-reducing effect, has good compatibility with formation water, can form ultra-low interfacial tension with crude oil, and is prepared from the following components by weight: 30-50% of an alkyl alcohol polyoxyethylene ether sulfate salt, 15-25% of a nonionic surfactant, 15-25% of an anionic surfactant, 2-5% of an organic solvent, 0.1-3% of sodium chloride, and 5-25% of water. According to the present invention, during the use, the low-tension viscosity-reducing oil displacement agent and the polyacrylamide polymer form the composite oil displacement system, wherein the polyacrylamide polymer can provide effects of water phase viscosity increasing, water-oil mobility ratio reducing, conformance expanding and profile control expanding, and the low-tension viscosity-reducing oil displacement agent can provide effects of oil-water interface tension reducing, oil displacement efficiency improving and crude oil viscosity reducing so as to further improve the water-oil mobility ratio, such that the extraction rate of the common heavy oil reservoir can be substantially improved through the synergetic effect of the polyacrylamide polymer and the low-tension viscosity-reducing oil displacement agent.

The invention discloses a viscosity-reducing oil displacement agent for heavy oil reservoirs, wherein the components comprise, by weight, 20-60% of an emulsifier, 1-5% of an ester-based compound, 0.2-2% of a wetting agent, and the balance of water. The invention further discloses a viscosity-reducing oil displacement agent-polymer system for heavy oil reservoirs, wherein the viscosity-reducing oil displacement agent-polymer system comprises 0.1-1% of the oil displacement agent, 0.05-0.3% of a polymer and the balance of water, and the polymer is polyacrylamide with a molecular weight of 8000000-20000000. According to the present invention, the viscosity-reducing oil displacement agent and the viscosity-reducing oil displacement agent-polymer system can provide good effects of viscosity reducing and emulsifying for heavy oil, can substantially reduce the viscous force of heavy oil in rock pores, can provide good profile control and water blocking effect, can effectively improve oil displacement efficiency, can improve heavy oil recovery, and are suitable for heavy oil reservoirs with a stratum viscosity of more than 200 mPa.s.

The invention discloses a chemical flooding alternate injection method, relates to optimization of a chemical flooding injection mode, and solves the problems of imbalanced distribution of injection rate, greatly reduced effective utilization ratio and low low-permeability oil layer producing degree simultaneously caused by the conventional ternary compound system general injection. The method comprises the following steps of: 1, injecting polymer plug A into the pore until the polymer plug A is in amount which is 10 percent of pore volume; 2, injecting ternary plug into the pore until the ternary plug is in an amount which is 10 percent of pore volume; 3, repeating the step 1 and the step 2 for 3 to 4 times; and 4, injecting polymer plug B into the pre until the polymer plug B is in an amount which is 10 to 12.5 percent of pore volume to finish chemical flooding injection. Compared with the general injection mode, the chemical flooding injection method of the invention has the advantages that: compound system expansion wave and volume effect are enhanced, the liquid absorption of a chemical agent by a low-permeability layer is improved, the effective utilization ratio of the chemical agent is improved and the yield is further improved by about 5 percent indoors under the condition of the same using amount.

The invention relates to a novel method capable of improving deep super-thick oil reservoir recovery efficiency. According to the method, in the steam huff and puff and steam flooding processes, a water-soluble nano-catalyst is injected to make the viscosity of super-thick oil under the condition of an oil reservoir be reduced substantially, as a result, the fluidity of the super-thick oil under the condition of the oil reservoir is improved, the shortcomings that a deep super-thick oil reservoir is high in steam injection pressure and low in well bottom steam dryness are effectively overcome, steam injection quantity also can be reduced, and the purpose of economical and efficient development of the deep super-thick oil reservoir is achieved. On the basis of steam huff and puff and steam flooding, the method of improving deep super-thick oil reservoir recovery efficiency can reduce the velocity of crude oil by more than 80%, increase the recovery percent by about 15%, and increase the gas-oil ratio in a huff and puff well period by 0.15.

The invention relates to the oil field oil extraction field and particularly relates to a low-concentration and efficient composite oil displacement composition. The composition contains the followingcomponents: sodium lauryl sulfate, N-dodecyl N methylpyrrolidinium bromide and partially hydrolyzed polyacrylamide. The composition contains simple components, and a surfactant oil replacement groupis formed by an anionic surfactant, a cationic surfactant or an additional nonionic surfactant and a cosurfactant, so that the taboo that the anionic surfactant and the cationic surfactant are hardlysimultaneously used is broken through; and the surfactant oil replacement group is further combined with oil replacement components of the composition, and the advantages of surfactant oil replacementand polymer oil replacement are adequately utilized, so that the oil extraction efficiency is comprehensively improved. Compared with common oil displacement composition products, the low-concentration and efficient composite oil displacement composition has the advantages that the use amount is fewer when an oil replacement solution is formed, the oil extraction can be remarkably lowered, the huge economic benefit can be created, and the composition has a potential market value.

The invention provides a multicomponent biological compound oil displacement agent system and an injection technology thereof and relates to a reservoir oil displacement agent production method and an application method. The oil displacement system is composed of petroleum hydrocarbon bacterium degrading agent and a biological compound oil displacement agent. The injection process of the system comprises the steps that 0.2 pv of biological compound oil displacement agent is injected from a block water well injection station with an injection well and an extraction well as designated zones according to the requirements for injection allocation flow speed and injection allocation quantity and then replaces 0.1 pv of petroleum hydrocarbon bacterium degrading agent, 0.2 pv of biological compound oil displacement agent is replaced, 0.1 pv of petroleum hydrocarbon bacterium degrading agent is continuously injected, 0.2 pv of biological compound oil displacement agent is injected, and finally water displacement is adopted. The multicomponent biological compound oil displacement agent system is suitable for medium-low-permeability heavy oil reservoirs after water displacement, is low in cost and free of pollution and does not damage the oil reservoirs. By utilizing the system and the injection process, the produced air pressure can be up to 1.0 MP or above after 76 hours, the system is diluted to make the concentration reach 5-10%, interfacial tension is up to 5.2 * 10-3-8.2 * 10-3mN/m, the viscosity reduction rate to heavy oil with the viscosity of 10000 mpa.s is up to 85.7%, and physical simulation shows that the average recovery rate is up to 18.0% or above.

The invention discloses a carbon-based amphiphilic nanoflow for oil displacement, which is prepared by the following steps of by taking carbon-based nanopowder as a raw material, modifying the carbon-based nanopowder by adopting a silane coupling agent and polyoxyethylene ether in sequence to obtain the carbon-based amphiphilic nanoflow. The carbon-based nano powder is selected from one of graphite powder, carbon powder, graphene or graphene oxide. The preparation method of the amphiphilic nanoflow comprises the following steps of dispersing carbon-based nanopowder in a mixed solvent of toluene and dimethylformamide in an equal mass ratio, then adding a silane coupling agent, sealing and stirring, reacting in an oil bath at 96 DEG C for 6 hours, and carrying out suction filtration, purification and drying to obtain silane coupling agent modified carbon-based nanopowder, dispersing the silane coupling agent modified carbon-based nanopowder into another part of mixed solvent of toluene and dimethylformamide in equal mass ratio, and adding polyoxyethylene ether, sealing and stirring, reacting in an oil bath at 90 DEG C for 6 hours, and carrying out suction filtration, purification and drying to obtain the carbon-based amphiphilic nanoflow. The carbon-based amphiphilic nanoflow disclosed by the invention can be directly prepared from oilfield injection water to obtain a carbon-based amphiphilic nanoflow dispersion liquid.

The invention discloses a viscoelastic surfactant system based on an oligomerization agent. The system is composed of 0.05%-0.5% of an ethoxy quaternary ammonium salt type oligomeric surfactant, 0.03%-0.8% of an anionic and nonionic surfactant and the balance of water. The anionic and nonionic surfactant provided by the invention is selected from alkylphenol polyoxyethylene ether sulfonate or sulfate, and alkyl alcohol polyoxyethylene ether sulfonate or sulfate. The viscoelastic surfactant system disclosed by the invention has double effects of profile control and displacement and viscosity reduction, can effectively reduce the viscosity of thickened oil, and greatly reduces the viscous force of the thickened oil in rock gaps, meanwhile, the water-phase viscosity can be improved, the fluidity ratio is reduced, the swept volume is increased, and therefore the water-drive thickened oil recovery rate is effectively increased.

The invention belongs to the technical field of sewage treatment, and particularly relates to a method for increasing the crude oil recovery ratio by using distillery wastewater. The method comprisesthe following steps of pretreatment of the distillery wastewater, an on-site injection stage of the distillery wastewater and an on-site test effect evaluation stage. According to the method for improving the crude oil recovery ratio by using the distillery wastewater, the problem of the high treatment cost and environmental pollution caused by discharging of the distillery wastewater is solved; and meanwhile, the method has the advantages of being simple in treatment method, simple in operation, less in investment, low in cost and good in on-site effect, the period of validity of an on-site test is 5 years or above, the input-output ratio is greater than 1:8, and the recovery ratio is increased by 12% or above. Therefore, the method can be widely used in the on-site test of increasing theoil reservoir recovery ratio.

The invention relates to a mud and sand blockage prevention and control technology suitable for water injection of a loose sandstone reservoir. According to the technical scheme, before water is injected into a stratum through an injection well, a salt water slug is injected into the stratum firstly, then a wetting reversal agent solution slug is injected, then a clay stabilizer solution slug is injected, and finally water injection is started. Salt comprises inorganic salt and organic salt. A wetting reversal agent is mainly a nonionic organic amine surfactant, a cationic surfactant and the like. A clay stabilizer is a clay particle migration prevention agent and is mainly an organic nonionic polymer, an organic cationic polymer and the like. The mud and sand blockage prevention and control technology has the beneficial effects that the technological operation is simple, hydration expansion and hydration dispersion of clay in the loose sandstone stratum can be effectively inhibited in the water injection process, mud and sand particle migration can be prevented from blocking a fluid seepage channel, and the permeability of the water injection stratum is not reduced; and meanwhile, the water injection sweep efficiency and the oil washing efficiency can be improved, secondary oil recovery and tertiary oil recovery are combined, and therefore the water injection recovery rate is increased.

The invention discloses an oil displacement agent based on microbial polysaccharide. The oil displacement agent comprises the following components in percentage by mass: 1%-30% of microbial polysaccharide, 5%-20% of a surfactant, 10%-30% of organic acid and 0.1%-5% of metal ions, with the balance of water, wherein the microbial polysaccharide is prepared from the following components in percentageby weight: 50 to 100% of pantoea polysaccharide, 0 to 50% of welan gum and 0 to 50% of xanthan gum. According to the invention, the viscosity of the oil displacement agent prepared by compounding themicrobial polysaccharide, the surfactant, the organic acid, the metal ions and the water can still be maintained at 300-400 mPa.s at 140 DEG C; and the prepared oil displacement agent can remarkablyimprove the displacement efficiency of an oil-displacing fluid and reduce a water-oil fluidity ratio, so the overall recovery ratio of in-place oil of crude oil is improved, and the oil displacement agent is a novel efficient oil displacement agent.