92results about How to "Improve the spread factor" patented technology

The invention relates to synthesis of polyoxyethylene fatty alcohol ether sulphonate, and complex formulation for tertiary oil recovery displacement agent, and belongs to chemical displacement agent technic field. The invention discloses a synthesis method of a surface active agent for tertiary oil recovery for a high-temperature, high salinity and high calcium and magnesium ion oil reservoir, and complex formulation for highly effective displacement agents. Polyoxyethylene fatty alcohol ether sulphate is reacted with a sulfonating agent under the action of catalyst to produce polyoxyethylene fatty alcohol ether sulphonate. Polyoxyethylene fatty alcohol ether sulphonate are used as main material which is complex formulated with heavy alkyl benzene sulfonate, water, polymerisate, etc. Compared with existing products, the displacement agent of the invention in the three-high system reduces the oil-water boundary tension ultra-low (10<-3>mN / m), and the boundary tension is not affected by temperature, degree of mineralization and the concentration of calcium and magnesium ions.

The invention relates to a technique combining the chemical huff and puff stimulation and the reversed plugging control. The technique adopts slug-type injection mode, including active agent slug, water plugging profile modification agent slug an displacement fluid slug, and includes the following steps: (1) firstly, injecting the active agent into the oil production layer, (2) injecting the water plugging profile modification agent 0-20 hours later, (3) then using excessive displacement fluid to lift all chemical agents to a place which is more than 3m away from well bore, and then using water to displace the excessive displacement fluid to the stratum and finally closing the well for 1 to 2 days for condensation. The purpose of the technique is to combine the huff and puff of the active agent with high oil-washing efficiency and low interfacial tension and the reversed profile control and flooding of the oil well, thus not only increasing the conformance factor of the injection of the water but also improving the oil displacement efficiency and extending the life circle.

The invention provides a cross-linked polymer microsphere-polymer composite deep water control agent and a using method thereof. The control and drive agent includes water-soluble cross-linked polymer microspheres, water-soluble polymers and water; in the composite deep-seated control and drive agent, the mass percentage of the water-soluble cross-linked polymer microspheres is 0.01% to 0.3%, The mass percent content of the water-soluble polymer is 0.05%-0.5%, and the balance is water. The cross-linked polymer microsphere-polymer composite deep control and flooding agent provided by the present invention has a higher liquid flow redirection ability than conventional polymer flooding, can delay the one-way breakthrough of the polymer solution in the application process, and improve the efficiency of polymer flooding. The sweep coefficient has a higher ability to improve the oil-water phase mobility ratio than the conventional cross-linked polymer solution, and improves the displacement ability of the cross-linked polymer solution, which is more suitable for water injection development reservoirs with heterogeneous porous media.

The invention discloses an oil well dual crosslinking selective plugging agent, and solves the problems that the selectivity of selective plugging agents in the prior art is not high, and effective plugging of a water layer and complete unblocking of an oil layer cannot be achieved. The oil well dual crosslinking selective plugging agent comprises the following components by mass: 2% of dispersing agent calcium lignosulfonate, 0.6% of suspending agent polyacrylamide, 0.9% of a cross-linking agent, 8% of oil soluble resin, and balance of water; wherein the 0.9% of crosslinking agent comprises 0.4% of reductant thiourea and 0.5% of oxidizing agent potassium dichromate. Compared with general plugging agents, water phase plugging rate and oil phase recovery rate of the oil well dual crosslinking selective plugging agent are higher, and the selective water plugging performance of the oil well dual crosslinking selective plugging agent is more superior.

The invention discloses a cation polyacrylamide gel microsphere and preparation method thereof. Molecular weight of the polyacrylamide gel is 10-30 millions, and diameter of the microsphere is 2-80 micron. The preparation method includes steps: mixing acrylamide monomer, methacryloyloxyethyl trimethyl ammonium chloride, N,N-methylene diacrylamide and ammonium persulphate to confect water solution, atomizing the water solution by compressed air, spraying the solution by atomization nozzle with aperture of 2-80 micron to oil phase of 80-120 DEG C for carrying suspension polymerization reaction and forming cation gel microsphere which size can be controlled by adjusting nozzle aperture according to oil layer rock pore scale. The cation gel microsphere is injected to oil layer with water in succeeding water drive after polymer drive, cross links with anion polymer remained in oil layer by positive and negative charge, and forms space meshy three-dimensional structure, thereby increasing flow resistance greatly, enhancing oil layer wave and coefficient again, and improving crude oil recovery ratio.

The invention discloses an experimental device and experimental method for thickened oil pool mixed nano-fluid alternating CO2 microbubble flooding. The experimental device and experimental method forthickened oil pool mixed nano-fluid alternating CO2 microbubble flooding introduces mixed nano-particles and combines the advantages of CO2 microbubbles, the phenomena of gas channeling and gravity override of a thickened oil pool occurred during conventional CO2 gas-water alternate flooding can be effectively controlled through a mode of alternating injection, and the recovery efficiency of thethickened oil pool is improved. Compared with CO2 gas, dissolving and diffusing abilities of the CO2 microbubbles are greater in crude oil, buoyancy is smaller, thickened oil viscosity can be better reduced, the volume of thickened oil is expanded, and the sweep coefficient is increased; the mixed nano-fluid can fully combine the advantages of various nano-particles, wettability of oil pull rockscan be changed, the oil-water interfacial tension can be reduced, and the oil washing efficiency is improved; and in addition, the experimental device and experimental method for thickened oil pool mixed nano-fluid alternating CO2 microbubble flooding adopts the method of injecting a mixed nano-fluid slug on the upper part of an oil pool and a CO2 microbubble slug on the lower part, controlling ofthe phenomena of the gas channeling and the gravity override and improvement of the vertical sweep coefficient are helped.

The present invention is foam-generating composition for high temperature stratum and its application in exploiting thick oil, and belongs to the field of surfactant technology. Chemicals capable of producing N2, CO2 and other gas are adopted to produce gases through the reaction of A+B+C-->N2+NH3+CO2+C, where A is reductant, B oxidant and C foaming agent. The reaction is controlled by temperature, and the foam-generating composition contains also surfactant with high heat resistance, high salt tolerance, high oil / water interface activity and high foam stability. After the chemicals are injected into the stratum at normal temperature, steam is injected to initiate reaction producing stable foam in the stratum, and the foam can plug to avoid steam fleeing, raise high temperature steam sweep efficiency, raise blotter efficiency, promote crude oil to disperse and raise the thick oil exploiting rate greatly.

The invention discloses an elastic granule profile control and displacement agent used for petroleum exploitation, which is a dispersion system prepared from 1,500mg / L functional polymer solution and elastic granules by mixing in water, wherein the elastic granules have a concentration of 0.05 to 3wt percent. The invention further discloses an oil displacement system formed by using the foam profile control and displacement agent and an oil displacement method. The oil displacement is achieved by using a combined slug consisting of functional polymers from high viscosity to low viscosity and the elastic grains, and is suitable for multiple kinds of anisotropic oil layers to effectively improve oil recovery, reduce ineffective water circulation, and improve economic benefits. Through the effective combination, the system can improve the recovery greatly, improve the total recovery to 90 percent or above and reduce the oil recovery cost greatly, and can be widely used for tertiary oil recovery.

The invention relates to a water block operation method for horizontal wells, in particular to a binary composite technique method of sealing and water block for horizontal well downholes; the invention is characterized in that dynamic and static data of wells under execution are analyzed prior execution, in order to determine filler consumption into a binary system; then, perform well killing with fresh water before filling forced hardening flue, mixed in certain proportion of polyropylene amide, resorcinol and urotropine, and nitrogen into the well through the oil pipe; form a partition board with the filled nitrogen, and block off the water cone formed by bottom water layer in the horizontal well; the method can both improve utilization rate of medium and low permeation layers, and effectively control high permeation water content, in order to reach the target of improve collection rate of horizontal wells. The method in particular adapts to blocking for high-permeation water bearing layers in horizontal wells.

The invention discloses a fracturing oil displacement method for improving the economic efficiency of thin-difference reservoir recovery of an old oil field. The method is based on oil reservoir evaluation and residual oil description. A fracturing measure process scheme is designed in a targeted manner, and a fine control fracturing technology is adopted the fracturing oil-displacing agent is injected into the stratum at high strength within a short time, the fracturing oil-displacing agent with good fracturing performance and a good displacing and washing effect is used for pressing open thestratum to generate cracks, meanwhile, a large amount of oil permeates into the stratum, the stratum energy is increased, stratum remaining oil can be efficiently displaced and washed, and then the recovery ratio of a thin-difference oil layer is greatly increased. According to the method, reservoir transformation, energy supplementing and chemical flooding washing are combined into a whole, therecovery efficiency can be comprehensively improved, construction parameters and fracturing oil displacement agent performance in fracturing can be reasonably optimized, and fracturing-injection-flooding washing integrated novel technology for improving the recovery ratio, which realizes the organic combination of a reservoir transformation technology and oil reservoir development integration andimproves the economic efficiency of thin-difference reservoir recovery of an old oil field.

The invention relates to an oil displacement composition used for low permeability oil reservoirs, and a preparation method thereof, and mainly solves the problems of easy stratum obstruction and difficult injection in the low permeability oil reservoir oil displacement process of present composite flooding polymers. The oil displacement composition contains a long carbon chain betaine surfactant and an inorganic salt, wherein the long carbon chain betaine surfactant is anyone selected from long chain carboxylic acid betaine and sulfonic acid betaine, the carbon chain is a C14-C40 alkyl or alkenyl group, the inorganic salt is anyone of or a composition of CaCl2, MgCl2, NaCl and NaHCO3, and a mass ratio of the long carbon chain betaine surfactant to the inorganic salt is 1:(1-100). The oil displacement composition has the advantages of formation of oil-water ultralow interface tension, decompression and augmented injection, and simple system, well solves the problems, and can be used in the intensified oil production process of the low permeability oil reservoirs.

The invention discloses a microbial oil recovery method. By the method, the crude oil production rate of a field test is improved by 12.5 percent. The microbial oil recovery method provided by the invention comprises the following steps of: 1) carrying out pure oxygen aeration on a culture solution of petroleum hydrocarbon degrading bacteria to obtain an injection solution which is subjected to the pure oxygen aeration; 2) mixing the injection solution which is subjected to the pure oxygen aeration in the step 1) and a bacteria solution which contains the petroleum hydrocarbon degrading bacteria to obtain a mixed solution; and 3) injecting the mixed solution which is obtained in the step 2) into an oil reservoir by a production well for oil recovery to obtain crude oil. The content of dissolved oxygen in the injection solution is increased in a mode of carrying out pure oxygen aeration on the injection solution in a storage tank, so the activity of aerobic and / or facultative microbes can be effectively improved, life activity such as growth metabolism of the aerobic and / or facultative microbes is quickened, the degree of hydrocarbon degradation is improved, and the crude oil production can be improved.

The invention discloses a microsphere profile control and displacement agent used for petroleum exploitation, which is a dispersion system prepared from functional polymer solution and microspheres with diameter of 0.2 to 20 mum by mixing, wherein the microspheres have a concentration of 0.05 to 0.2wt percent. The invention further discloses a combined oil displacement system formed by using the foam profile control and displacement agent and a combined oil displacement method. The oil displacement is achieved by using a combined slug consisting of functional polymers from high viscosity to low viscosity and the microspheres, and is suitable for multiple kinds of anisotropic oil layers to effectively improve oil recovery, reduce ineffective water circulation, and improve economic benefits. Through the effective combination, the system can improve the recovery greatly, improve the total recovery to 70 to 89 percent or above and reduce the oil recovery cost greatly, and can be widely used for tertiary oil recovery.

Disclosed is a three-in-one composite profile control and displacement process used for oilfield deep profile control. The process includes that injecting a prepared liquid polymer microsphere solution, then injecting a three-adoption oil displacing agent solution, and finally injecting two-fluid process profile control agent, wherein liquid polymer microspheres selectively enter strata, expand when encountering water and play a role in deep sealing, the oil displacing agent can facilitate expansion of the liquid polymer microspheres and can play a role in oil displacement, and the two-fluid process profile control technology plays a role in sealing and improving profile control strength. Through combining of three products, deep profile control and sweeping area increase can be realized, and crude oil recovery efficiency can be effectively improved.

The invention discloses a method for exploiting extra-heavy oil or super-heavy oil in a fireflood-assisted gravity oil drainage mode of horizontal wells. The method includes the steps that an injection-production well pattern is deployed for a selected extra-heavy oil and / or super-heavy oil reservoir; each vertical gas injection / ignition well in the well pattern corresponds to one or more horizontal production wells; gas injection and ignition are conducted on the vertical gas injection / ignition wells; after combustion is stable, the gas injection speed is raised gradually, the gas discharging speed is also raised as the gas injection speed is raised, the ratio of the total daily gas discharging amount of all the horizontal wells to the daily gas injection amount of the vertical wells is controlled to be 0.9-1.0; therefore, stable oil drainage production of all the horizontal wells is achieved. By means of the method, the engineering risks of firewire propelling and displacement, horizontal wellbore fire surging and the like existing in the fireflood-assisted gravity oil drainage process of horizontal wells in the prior art can be avoided, and safe and steady production is achieved.

The invention discloses a low-permeability oil reservoir non-mixed-phase gas-water alternate injection and fluctuation depressurization augmented injection device and method. The device mainly comprises a gas-liquid injection device on the ground and a gas-water alternate injection and fluctuation depressurization augmented injection device in a downhole. The gas-liquid injection device mainly comprises a low-temperature high-pressure liquid storage tank, a liquid distribution tank and a plunger pump on the ground. The gas-water alternate injection and fluctuation depressurization augmented injection device comprises a mixed fluid acceleration inlet segment, a collision body, a shell and a mixed fluid outlet segment. According to the device, the effects of the elasticity modulus difference and gravitational differentiation of gas and liquid are utilized to achieve mutual conversion between gas-water alternate injection, injected liquid fluctuation depressurization augmented injection and non-mixed-phase gas bubble anti-channeling functions, and therefore injection efficiency is enhanced, and the phenomenon of gas channeling is eliminated. The device is simple in structure, the construction method is simple, and operation cost is low; the operation process can be adjusted in real time according to injection pressure, the effect of gas (liquid) absorption is effectively improved, and the production efficiency of the low-permeability oil reservoir non-mixed-phase gas drive is substantially enhanced.

The invention discloses an oil-in-water emulsion oil displacement agent for crude oil chemical flooding for recovery efficiency improvement. The oil-in-water emulsion oil displacement agent is prepared from, by weight, 1-5 % of nano silica sol, 0.02-0.2% of octadecyl dimethylamine, 5-10% of 5 # white oil and the balance water and is prepared through mixing, wherein the particle size of the nano silica sol is 7-12 nm, and the weight percentage content sum of the components is 100%. The viscosity and stability of oil-in-water emulsion is improved by adding nano silica, the oil-in-water emulsion can improve the displacement efficiency of chemical flooding and also improve sweep efficiency and can improve the displacement efficiency by 30% or above based on water flooding by serving as the oil displacement agent for tertiary oil recovery.

The invention relates to a foam-assisted gravity oil driving method. The foam-assisted gravity oil driving method comprises the steps that a well is drilled as a production well at the lower part of an oil reservoir, a straight well is drilled as an injection well at the top of the oil reservoir, foam is continuously injected into the injection well, and the foam injection volume is controlled tobe 0.01-0.2 PV, oil is pushed in high and low permeable parts by using the foam, after being broken, the foam is accumulated to form a secondary gas cap to displace top attic oil, so that the more foam can enter the low permeable part, the high and low permeable parts achieve the effect of simultaneous propulsion, and sweep coefficient is improved; after the foam is broken, released gas enters thehigh part of a structure under the action of gravity differentiation, the gas is gathered continuously to form the secondary gas cap, the top attic oil is displaced, and the sweep coefficient is further improved; and a surfactant in a foam system can greatly reduce interfacial tension of oil and water, so that original oil in a restrained state becomes flowable oil, and the oil washing efficiencyis improved.

The invention provides a CO2 gas soluble foaming agent and a preparation method and application thereof, and belongs to the field of oil field chemicals. The CO2 gas soluble foaming agent is allyl polyoxyethylene ether fluorine-containing polyurethane sodium sulfonate which is obtained by sultified reaction of sodium bisulfate aqueous solution and allyl polyoxyethylene ether fluorine-containing polyurethane Z, wherein the allyl polyoxyethylene ether fluorine-containing polyurethane Z is a product of diazonium addition reaction of fluorine-containing alcohol Rf-Oh, R2 substituted allyl polyether and isocyanate group in diisocyanate CON-R1-NCO. The allyl polyoxyethylene ether fluorine-containing polyurethane sodium sulfonate can be alone dissolved in CO2 or dissolved in CO2 with a dissolved in CO2, subsequently injected into the formation, preferentially enters a high permeability zone with the CO2, and meets bound water in the formation or a subsequent auxiliary slug to use as a foaming agent to produce foams to inhibit fluid channeling in subsequent CO2 displacement process.

This invention discloses a method for preparing polyacrylamide reverse phase emulsion profile control agent. The method comprises: preparing organic crosslinker, preparing polyacrylamide reverse phase emulsion, and preparing polyacrylamide reverse phase emulsion profile control agent. When used, 0.8-2% polyacrylamide reverse phase emulsion profile control agent is mixed with 400-3500 mg / L phase-reverse agent and oil field wastewater at 30-45 deg.C, and filled into the oil layer through a water-injection well. The phase-reverse gelation time is 2-15 days, and the gel viscosity is higher than 5000 MPa.s.

The invention provides a preparation method of a microbial self-healing gel profile control agent.The preparation method includes the following steps that a microbial nutrition concentrated solution is prepared, then the solution is mixed with microorganisms, and microbial suspension liquid is formed; 2-3% of sodium alga acid, 4-6% of acrylamide, 0.1-0.3% of N' N-methylene bisacrylamide and 0.5-0.6% of N, N, N', N'-tetramethylethylenediamine are added to the microbial suspension liquid, and first reaction liquid is formed; 2-4% of a cross-linking agent, 0.2-0.25% of initiator and water are mixed, and second reaction liquid is formed; the first reaction liquid is mixed with the second reaction liquid, a reaction is conducted for 2-3 hours at the normal temperature of 20-25 DEG C, washing is conducted, and the microbial self-healing gel profile control agent is obtained; the optical density of the microbial suspension liquid at the position of 600 nm is 1.5-2.The invention further provides the microbial self-healing gel profile control agent prepared through the preparation method and application of the same to oil exploitation.

The invention relates to a heavy oil multiphase thermal huff and puff oil recovery method. By adopting the heavy oil multiphase thermal huff and puff oil recovery method, the main problems that the existing steam huff and puff oil recovery method is performed in a place which is far away from a near wellbore zone, the recovery is difficult due to temperature drop and the recovery rate is low are solved. The heavy oil multiphase thermal huff and puff oil recovery method is characterized in that mixed gas of high-temperature and high-pressure water vapor, N2 and CO2 is generated by combustion of a rocket power oil recovery device, the mixed gas, a high-temperature foaming agent and the water vapor generated by a steam boiler are injected into a formation, and the injection time and the sequence of all components are determined according to the status of the formation, subject to the fact that the pressure can not exceed the bursting pressure of the formation. The heavy oil multiphase thermal huff and puff oil recovery method has the characteristics of high recovery rate and good oil driving effect in the place which is far away from the near wellbore zone.

The invention discloses an environment-friendly salt-resistant high-temperature-resistant oil displacement agent containing biological surfactant and used in the petrochemical industry. The oil displacement agent comprises, by weight, 0.1 to 1.2 parts of sodium surfactin, 5 to 8 parts of tea saponin modifier and 80 to 85 parts of water. According to the invention, the sodium surfactin, the tea saponin modifier and other auxiliary components are combined for preparation of the oil displacement agent; the oil displacement agent can be used for exploitation of high-water-content, low-permeability, thickened, high-temperature and high-salt oil reservoirs and can improve oil displacement efficiency, sweep efficiency and recovery efficiency; the tea saponin modifier is prepared from tea saponin extracted from tea seed meal, so cost for the raw materials of the oil displacement agent is reduced; moreover, because of the characteristics of the sodium surfactin and the tea saponin, the sodium surfactin can be decomposed into 4 single amino acids and the tea saponin can be naturally decomposed by microorganisms after demulsification of crude oil; and the separated oil displacement has excellent degradation performance, so secondary pollution caused by incapable degradation of the separated oil displacement is avoided and environmental protection effects are obtained.

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.

This invention discloses a method for preparing self-crosslinking polymer profile control agent, which is prepared from acrylamide, cationic monomer DMC, self-crosslinking monomer carboxymethyl acrylamide and water at a weight ratio of (9.07-12.38) : (0.09-0.64) : (2.53-5.29) : (83-86). The method comprises: adding initiator 50 mg / L to the above raw materials at 28-32 deg.C, and copolymerizing for 10-13 h. The crosslinking time of self-crosslinking groups and amide groups in the prepared self-crosslinking polymer is adjustable, thus the formed gel can realize profiles control, and has raised sweep coefficient.

The invention discloses a multiple thermal fluid composite system oil displacing method and particularly relates to a method for economically and effectively improving the oil recovery rate for the later period of water displacing normal heavy oil reservoir exploitation. The method comprises the steps of a, injecting mixtures, which is 0.15-0.2 time the formation pore volume, of hot water and flue gases; b, injecting a foaming agent solution into a water injection well for 25-30 d; c, injecting a viscosity reducer solution into the water injection well for 5-10 d; d, injecting the mixtures of hot water and flue gases for 60-80 d; e, repeating the steps b, c and d. The method displaces a great amount of residual oil which cannot be extracted through common water displacing in an oil reservoir, the heavy oil reservoir recovery rate after water displacing is improved greatly by 26.4%, and the final reservoir recovery rate can reach 48.8%. Meanwhile, flue gases generated by combustion are directly injected underground, the thermal efficiency can be improved by more than 10%, and environment pollution is reduced.

The invention provides a fracture-cave type reservoir space structure injection-production pattern optimal design method. Multiple wells are arranged in an oil field block; and the fracture-cave type reservoir space structure injection-production pattern optimal design method comprises the following steps: S1) multiple initial injection-production schemes are determined according to the positions of all the wells or the types of reservoir bodies of all the wells; S2) the communication degrees of the injection-production wells in each initial injection-production scheme are calculated; S3) Gini coefficients of the communication degrees of the injection-production wells are calculated according to the communication degrees of the injection-production wells in each initial injection-production scheme; and S4) the initial injection-production scheme with the smallest Gini coefficient is selected as a final injection-production scheme. The fracture-cave type reservoir space structure injection-production pattern optimal design method prevents one-way acting caused by feeding of injected water along a high-guide channel, and improves the conformance efficiency of the injected water.

The invention provides a method for raising the recovery efficiency of a heavy oil deposit through chemical steam flooding. The method comprises steps of: 1. selecting an oil deposit and injecting steam, wherein the burial depth of an oil layer of the selected oil deposit is 900 to 1600 m, the effective thickness of the oil layer is greater than or equal to 8 m, the viscosity of crude in the oil layer is greater than 100 mPa.s, and the volume of the injected steam is 0.2 to 0.25 times of that of pores in the stratum; 2. injecting a foaming agent, nitrogen and steam in a steam injection well in a mixed mode for 10 to 30 days, wherein the ratio of the injected foaming agent to the injected steam, by mass, is equal to (0.4 to 1.2) to 100, and the ratio of the injected nitrogen to the injected steam, by volume underground, is equal to (0.5 to 1.5) to 100; 3. injecting an oil displacement agent and steam in the steam injection well in a mixed mode for 5 to 10 days, wherein the ratio of the oil displacement agent to the injected steam, by mass, is equal to (0.2 to 0.8) to 100; 4. only injecting steam for 80 to 120 days; and 5. repeating steps 2, 3 and 4. The speed of steam injection is 1.6 to 2.0 ton / day, hectare, thickness per meter.

This invention discloses Streptococcus zooepidemicus (CGMCC No.1988) for reducing petroleum viacosity and increasing petroleum yield, and its application. Streptococcus zooepidemicus is applied by: inoculating in petroleum, and fermenting at 20-60 deg.C for 8-72 h. Streptococcus zooepidemicus can reduce petroleum viacosity from 8000-15000 mPa.s to 50-250mPa.s, increase petroleum acid value by 8-15 times and light component contents, reduce wax and glue contents by 50-95%, improve rheological property of petroleum, reduce interfacial tension between water and oil, increase organic acid contents in fermented petroleum, and increase oil layer pressure and petroleum fluidity. Besides, CO2, biogas and hyaluronic acid are generated during the fermentation process, thus fermented petroleum is easy to emulsify, moisten and disperse. Streptococcus zooepidemicus can be used in oil production, especially microbe-enhanced oil production and petroleum transportation.

The invention discloses an environment-friendly tertiary oil recovery oil-displacing agent based on a biosurfactant. The environment-friendly tertiary oil recovery oil-displacing agent is prepared from the following ingredients in parts by weight: 0.6-1.0 part of sodium bacillus subtilis lipopeptide, 25-35 parts of alkylbenzene sulfonate, 8-12 parts of betaine amide, 1.5-2 parts of a tea saponin modifier, 1.2-1.5 parts of a cosurfactant, and 50-65 parts of water, wherein sodium bacillus subtilis lipopeptide, the tea saponin modifier, alkylbenzene sulfonate and betaine amide are mutually blended to prepare the tertiary oil recovery oil-displacing agent. The tertiary oil recovery oil-displacing agent can be used for exploiting a high-water-content, low-permeability, oil-thickened, high-temperature and high-salt oil deposit, so as to improve the oil displacement efficiency and the sweep efficiency, and increase the recovery efficiency up to about 15%; after demulsification of the crude oil, due to the properties of sodium bacillus subtilis lipopeptide and tea saponin, the separated oil-displacing agent is excellent in degradability, so as to avoid secondary pollution due to the condition that the separated oil-displacing agent cannot be degraded, and then achieve the environment protecting effect.