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

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 relates to a fluorocarbon surfactant binary composite foam flooding system. The system is prepared by adopting fluorocarbon surfactant as a foaming agent, adopting a macromolecular compound as a foam stabilizer and adding water; the foaming agent is one or combination of sulphobetaine type fluorocarbon surfactant and amine oxide type fluorocarbon surfactant, or combination of alpha-alkenyl sulfonate and one of sulphobetaine type fluorocarbon surfactant and amine oxide type fluorocarbon surfactant; and the foam stabilizer is partially hydrolyzed polyacrylamide, polyvinyl pyrrolidone K30, polyvinyl pyrrolidone K90 or hydroxyethyl cellulose. An application method comprises that solution of the fluorocarbon surfactant binary composite foam flooding system and nitrogen are alternately injected into a stratum or a rock center so as to improve the recovery rate of crude oil.

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 viscoelastic surfactant system, which is composed of a cationic oligomeric surfactant, an anionic nonionic surfactant, a small molecule additive and water, and the cationic oligomeric surfactant accounts for 0.01% to 1%. Anionic and nonionic surfactants account for 0.05% to 3%, and small molecule additives account for 0.02% to 5%. The anionic nonionic surfactant is selected from alkylphenol polyoxyethylene ether sulfonate and alkyl alcohol polyoxyethylene ether sulfonate. The application of the viscoelastic surfactant system of the present invention in the production of water flooding heavy oil reservoirs. The viscoelastic surfactant system of the present invention has dual functions of regulating and driving and reducing viscosity, can effectively reduce the viscosity of heavy oil, and greatly reduce the viscous force of heavy oil in rock voids; at the same time, it can also increase the viscosity of the water phase, Reducing the mobility ratio and increasing the swept volume can effectively improve the efficiency of water flooding; it can also reduce the oil-water interfacial tension to an ultra-low range, thereby effectively improving the recovery of heavy oil in water flooding.

The invention discloses a carbon-based amphiphilic nanofluid for oil displacement. Using carbon-based nanopowder as a raw material, it is modified with a silane coupling agent and polyoxyethylene ether successively to obtain a carbon-based amphiphilic nanofluid. ; Carbon-based nano-powder is selected from a graphite powder, carbon powder, graphene or graphene oxide. The preparation method of the amphiphilic nanofluid is as follows: disperse the carbon-based nanopowder in a mixed solvent with an equal mass ratio of toluene and dimethylformamide, then add a silane coupling agent, seal and stir, react in an oil bath at 96 °C for 6 h, and pump Filter, purify and dry to obtain the carbon-based nanopowder modified by the silane coupling agent; disperse the carbon-based nanopowder modified by the silane coupling agent in another mixed solvent of toluene and dimethylformamide in the same mass ratio; Polyoxyethylene ether was added, sealed and stirred, and the reaction was carried out in an oil bath at 90° C. for 6 hours. The carbon-based amphiphilic nanoflow was obtained by suction filtration, purification and drying. The carbon-based amphiphilic nanofluid of the present invention can be directly prepared with oil field injection water to obtain a carbon-based amphiphilic nanofluid dispersion.

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 discloses a viscosity-reducing oil-displacing agent applicable to thick oil reservoirs. The viscosity-reducing oil-displacing agent is prepared from a nonionic surfactant, a cationic oligomeric surfactant, C1-C6 organic micromolecular alcohol and water. The cationic oligomeric surfactant is selected from a compound shown in a structural formula (I), wherein R refers to C4-C18 alkyl,and X is selected from one or more of F<->, Cl<->, Br<-> and I<->. The invention further discloses viscosity-reducing oil-displacing agent-polymer system applicable to the thick oil reservoirs. The system comprises the viscosity-reducing oil-displacing agent, polyacrylamide in molecular weight of 8,000,000-2000,000,0 and water. The viscosity-reducing oil-displacing agent is capable of remarkably reducing oil-water interfacial tension and has great viscosity reducing and emulsifying effects on thick oil. The viscosity-reducing oil-displacing agent-polymer system is capable of improving a water-oil mobility ratio, sharply reducing viscous force of the thick oil in rock pores, effectively improving oil displacing efficiency and improving thick oil recovery efficiency.

The invention discloses a low-crosslinked polymer oil displacement system used for high temperature oil reservoirs, and belongs to the technical field of oilfield exploitation tertiary recovery. The oil displacement system is mainly composed of 800-1800mg / L of partially hydrolyzed polyacrylamide (HPAM) and 30-300mg / L of an organic phenol-aldehyde crosslinking agent, and a concentration ratio of the partially hydrolyzed polyacrylamide to the organic phenol-aldehyde crosslinking agent is greater than 6. The low-crosslinked polymer oil displacement system used for high temperature oil reservoirs has the characteristics of high viscosity, good long-term stability and good injection performance, can be applied in the oil reservoirs with the temperature of 80-95DEG C, and solves a problem that a chemical oil displacement technology cannot be applied in high temperature oil reservoirs; and the oil displacement system has substantial oil increasing and water reducing effects in 93.7DEG C high temperature oil reservoir VII1-3 bed series with the comprehensive water content of 98.7% and the recovery percentage of 42.1%.

A heavy oil recovery method that enhances water flooding efficiency by electric heating. First, the electric heating tube or electric heating cable is fixed in a ring shape outside the isolation tube with grooves, and the production string is lowered to the target oil reservoir, and the isolation tube is expanded and isolated. The heating tube makes the heating tube close to the production casing to heat the formation near the well; after the heating distance reaches the preset value, the heating is continued and the heating power is adjusted to continuously reduce the viscosity of the heavy oil near the production well. Flow resistance and mobility ratio; start the ordinary heavy oil water flooding production process, inject displacement fluid into the injection well, and displace the crude oil in the formation to move towards the production well; the crude oil, water and gas flowing to the production well pass through the lift in the production well The device is lifted to the ground. The invention combines thermal recovery and cold recovery, reduces the flow resistance and displacement fingering in the near-well area of ​​the production well, accelerates the effective production period of water flooding and the recovery efficiency of heavy oil, and improves the ultimate recovery rate.