253 results about "Recovery factors" patented technology

The invention discloses a method for using combustion and stream combination flooding to exploit thick oil. The method comprises the following steps of: carrying out vapor huff and puff exploitation in a heavy crude oil reservoir; carrying out in-situ combustion exploitation after forming thermal linkage; and changing single air charging to be simultaneous charging of air and water vapor in certain proportion to carry out combination flooding exploitation. A proper optimal configuration relationship of air /vapour charging speed is selected, so as to improve combustion wave and volume of the oil reservoir and improve exploitation effects of in-situ combustion and the ultimate recovery factor.

The invention particularly provides a temporary blocking turnaround fracturing method based on surface modified polyvinyl alcohol fibers. The method comprises the following steps that 1, the surfaces of the water-soluble poly(vinyl alcohol) fibers are modified; 2, fracturing work liquid is prepared; 3, liquid in a shaft is extruded out by and replaced with active water; 4, setting is carried out on a facture packer; 5, prepad fluid is injected, and a major fracture is formed; 6, the water-soluble degradable fiber temporary blocking fracturing liquid is injected into the formed major fracture in a step mode and injected into a stratum to form a new branch fracture; 7, the prepad fluid is injected into the formed new branch fracture, and the length of the fracture is expanded; 8, sand-carrying liquid is injected into the formed new branch fracture in a step mode; 9, the sand-carrying liquid in the shaft is extruded out by and replaced with active water. An old facture or a facture filled with sand is temporarily blocked, the new fractures are made on the original fracture in a certain angle direction, more unused areas of natural fractures and primary fractures are communicated, a new fracture flow leakage system is formed, oil and gas production and the ultimate recovery factor of an oil and gas field are improved, and the aims of restoring the yield of an old well and achieving facture production increase of a new well are achieved.

The invention provides a method for preparing low-cost polyacrylamide nano microspheres by two times of microemulsion polymerization. The prepared polyacrylamide nano microspheres are used for improving an oil recovery factor. The method comprises: firstly, preparing a dispersion of polyacrylamide nano microspheres by microemulsion polymerization; secondly, adding a monomer and aqueous solution of an initiator into the product of the primary polymerization serving as a dispersion medium to form microemulsion by using an emulsifier in the dispersion medium; and finally, initiating polymerization again to obtain high-content polyacrylamide nano microspheres. As no oil soluble solvent and emulsifier are added for the secondary polymerization, the synthesis cost of the polyacrylamide nano microspheres can be reduced considerably. The prepared polyacrylamide nano microsphere system can be directly diluted by water to form polymer microsphere aqueous solution at required concentration and can be used alone or in combination with other oil-field chemicals in fields of profile control, water plugging, fuel scavenge and the like for improving recovery operation.

A method for selecting a candidate reservoir for enhanced oil recovery from a plurality of reservoirs comprising selecting a reservoir, calculating a normalized raw score based on target oil for the reservoir (S_{Target Oil}), calculating a normalized raw score based on recovery factor for the reservoir (S_{Recovery Factor}), and evaluating the plurality of reservoirs based on S_{Target Oil} and S_{Recovery Factor}.

The invention relates to a flooding system used for improving the recovery factor after polymer flooding and a preparation method thereof, which belongs to the technical field of enhanced recovery of oil fields. A surfactant with unlike charges and a polymer react with each other to produce a high-activity compound; and the high-activity compound is mixed with a non-ionic surfactant to produce the novel flooding system. The novel flooding system solves the problems of the poor temperature resistance and the inorganic high valence cation resistance of the prior flooding system. The novel flooding system has the advantages of high viscocity, ultra-low interfacial tension, low feeding quantity and so on. The system has wide application prospects in oil fields to apply the technology for improving the oil recovery factor.

Conductive particles each includes a polymer base particle and a conductive layer coating the polymer base particle. Let the compressive elastic deformation characteristic K_X of one conductive particle when the displacement of particle diameter of the conductive particles is X % be defined by the following formula: K_X=(3/√2)·(S_X^−3/2)·(R^−1/2)·F_X. F_X is the load (N) necessary for X % displacement of the conductive particles. S_X is the compressive deformation amount (mm) upon X % displacement of the conductive particles. R is the particle radius (mm) of the conductive particles. The compressive elastic deformation characteristic K₅₀ when the displacement of particle diameter of the conductive particles is 50% is 100 to 50000 N/mm² at 20° C., and the recovery factor of particle diameter of the conductive particles when the displacement of particle diameter of the conductive particles is 50% is not less than 30% at 20° C.

The invention relates to an icebound type pressure-maintaining and temperature-preserving sampler. The icebound type pressure-maintaining and temperature-preserving sampler comprises a drilling in/sampling switching mechanism, a refrigerating fluid circulating system, a slurry ice valve and core valve in-situ generation mechanism, a core accommodating pipe single acting mechanism and channels I, II, III, IV, V and VI; the slurry ice valve and the core valve which are generated by freezing are used to replace mechanical valves of a ball valve or a plate valve and the like to close an upper port and an lower port of a sampling drilling tool, solid impurities in a hole have no influence on the closing process, thereby the sampler has high reliability and solves the problems of difficult starting, difficult closing caused by easy blockage of sundries in the hole and the like of the tradition mechanical valves and improves pressure-maintaining reliability and success ratio; and moreover, radial dimension can be smaller so as to be beneficial to acquiring cores with larger diameters and improving hydrate coring recovery factor. Tests prove that the ice valve can realize the sealing of 25MPa, which is suitable for drilling on hydrate with an inner hole liquid column reaching 2500m; and a hydro hammer drives a reciprocating pump, which utilizes the slurry as dynamic medium, thereby avoiding the complexity brought by an electric structure and having simplicity and reliability.

The invention provides a supercritical CO2 microemulsion and a method for improving an oil recovery factor. The supercritical CO2 microemulsion comprises the following raw materials in percentages by weight: 4.5*10<-3>wt% to 16.5*10<-3>wt% of a surfactant, 12.0wt% to 14.5wt% of a cosurfactant, 0.2wt% to 1.8wt% of water, and 83.7wt% to 87.8wt% of CO2, wherein the surfactant is one of 2-(1-ethyl-2-methyl-1-pentyl) sodium sulfosuccinate or a homolog of 2-(1-ethyl-2-methyl-1-pentyl) sodium sulfosuccinate, polyethylene glycol-2,6,8-trimethyl-4-nonyl ether, perfluorinated alkyl polyoxyethylene, polyacrylic acid 1,1-perfluorooctyl dihydrogen phosphate, polydimethylsiloxane, and polyacrylic acid 1,1-dihydrogen perfluorinated octyl methyl ester-b-polyoxyethylene; and the cosurfactant is ethanol, propyl alcohol, butanol, pentanol or hexyl alcohol. The invention also provides a method for improving an oil recovery factor. The method comprises a step of improving the oil recovery factor by adopting the supercritical CO2 microemulsion.

The invention relates to a method and apparatus for using stalk enzyme remainder to fast prepare for liquid fuel with high quality (biological oil) in the field of energy chemical technology. It adds rotating perforated plate distributor, fast separator, cyclone separator and pipe-walls spray thrower and so on. It controls the distributing condition so that the stalk remainder dose fast distributing by the rotating perforated plate distributor to obtain the liquid flue with high heat value. The invention also provides a device to obtain the high liquid recovery factor biology oil.

The present invention refers to a biotechnological process that enhances oil recovery of a 14 to 25 API Gravity oil contained in carbonate-containing and/or clayey sandstone porous rock systems with low permeability (7 to 100 mD), thus focused to petroleum wells associated to zones with low recovery factor. The process utilizes the indigenous extremophile microorganisms activity from the oil reservoir and an IMP culture, as well as its metabolites (gases, acids, solvents and surfactants), which improve oil mobility and are able to develop at 60 to 95° C. temperatures, 7 to 154.6 Kg/cm² (100 to 2,200 psi) pressures and NaCl content from 5,000 to 45,000 ppm, in anaerobic conditions. The biotechnological process of the present invention includes: indigenous microorganisms sampling, collecting and characterization from the reservoir; formulation of culture media; selection, enrichment, activation and preservation of such microorganisms, as well as biostimulation (indigenous microorganisms) and bioaugmentation (IMP culture) to increase the metabolite production, useful for oil recovery in a porous media impregnated with oil in carbonate-containing and/or clayey sandstone porous systems, with one or several cycles and confinement periods from 5 to 10 days, to increase oil recovery. Experimental tests show that the biotechnological process of the present invention supplies an oil recovery increase up to 30%, additional to that obtained in secondary recovery processes.

The invention discloses a Brevibacillus borstelensis Po CGMCC No. of 2441 and the application thereof. A microbial inoculum that contains the brevibacillus borstelensis Po CGMCC No. of 2441 also belongs to the extent of protection of the invention. Model oil displacing experiment results indicate that after the oil displacement with polymers, the brevibacillus borstelensis oil displacement can be used for raising the recovery factor by 3 to 5 percent (OOIP), the brevibacillus borstelensis oil displacement combined with a polymer protecting slug can be used for raising the recovery factor by about 7 percent (OOIP), and a brevibacillus borstelensis oil displacing method that is combined with chemical oil displacement can be used for raising the recovery factor by 6 to 13 percent (OOIP). The experiment results indicate that the strain can be widely applied into the field of oil exploiting industries and particularly into the field of enhanced microorganism oil exploiting, and is applicable to large-area popularization and application.

The invention discloses a method for explosion and leakage increase of a low permeability sandstone uranium deposit, which includes steps as follows: A. blast holes are drilled through the overburden, the top rock of occurrence terrane to the proper position of the occurrence terrane from surface. An underreamer is used to locally ream the blast holes at the occurrence terrane to meet charging requirement; B. blasting cartridges are arranged in the blast holes in an uncoupling way; the detonator is waterproof; uncoupling charge for explosion comprises radial uncoupling charge and axial uncoupling charge; C. after the blasting cartridges are arranged properly, hole seal measures shall be taken to build up the blast holes; D. the blasting cartridges are initiated through short delay blasting which comprises short delay blasting inside the blast holes and short delay blasting between the blast holes. The recovery factor and the yield per unit of in-situ Uranium leaching are improved; the uranium deposit resource of low permeability sandstone type is used completely, thus alleviating the shortages of uranium resources.

The invention discloses an artificially resonant wave strengthened oil displacement dynamic simulation experimental device and an experimental method. The experimental device comprises an artificially resonant wave test bed, core grippers fixed on the artificially resonant wave test bed, thermotanks distributed outside the core grippers, an intermediate transitional water-delivery container, an intermediate transitional oil delivery container, a water storage tank, an oil storage tank, and liquid containers connected with liquid outlets of the core grippers. The experimental device comprises the following steps of: 1, performing an unartificially resonant wave dynamic simulation experiment; 2, replacing cores and performing an artificially resonant wave dynamic simulation experiment on the plurality of cores under the artificially resonant wave vibration conditions of different frequency and identical vibration acceleration; and 3, performing data processing. The device and the methodensure rational design, convenience of distribution, use and operation, perfect functions and good simulation effect; and the single-phase and two-phase seepage characteristics of the cores, the saturation of residual oil and the final oil recovery factor can be tested under the conditions of artificially resonance waves and different displacing mediums.

The present invention is related to the obtaining and using of multifunctional foaming compositions with wettability modifying, corrosion inhibitory and inhibitory/dispersants mineral scale properties with high stability in environments of high temperature, high pressure and tolerance to high concentrations of divalent ions such as calcium, magnesium, strontium and barium. The multifunctional foaming compositions are obtained from the combination of supramolecular complexes resulting from interactions of alkyl amido propyl hydroxysultaines and/or alkyl amido propyl betaines and/or alkyl hydroxysultaines and/or alkyl betaines and anionic surfactant of type alkyl hydroxyl sodium sulfonate and alkenyl sulphonates of sodium, with cationic surfactants as tetra-alkyl ammonium halides and copolymers derivatives of itaconic acid/sodium vinyl sulfonate and/or terpolymers derived from itaconic acid/sodium vinyl sulphonate/aconitic acid. These multinational foaming compositions control the gas channeling and favorably change the wettability and increase the recovery factor of crude oil in naturally fractured reservoirs of carbonate type and heterogeneous lithology. In addition to this, the multifunctional foaming compositions of this invention exhibit anti-corrosive properties in typical environments of production tubing of crude oil and antifouling/dispersants of mineral salts as calcium carbonate, calcium sulfate, barium and strontium in the reservoir and in the production and injection pipelines.

Method of estimating the recovery factor for the volume drained by at least one producing gas well that penetrates a tight gas reservoir or a coal bed methane reservoir, by (a) calibrating changes in the isotopic composition of at least one component of the gas that is produced from the gas well with increasing recovery factor, (b) obtaining a sample of produced gas from the producing gas well and analyzing the sample to obtain the isotopic composition of the component of the produced gas and (c) using the calibration obtained in step (a) and the isotopic composition determined in step (b) to estimate the recovery factor for the volume drained by the gas well. The estimate of the recovery factor determined in step (c) and the cumulative volume of gas produced from the gas well is used to determine the volume drained by the gas well.

The invention discloses a method for displacing coal seam gas via horizontal well mixed gas, relating to the method of coal seam gas coal mining, which comprises the following steps: 1. A plurality of horizontal wells (10) are formed in the coal seam (30) through the horizontal well craft, which comprise injection wells (11) and harvesting wells (12) alternatively arranged at intervals ; 2. A high-pressure injecting equipment is used to inject the mixed gas into the coal seam (30) with coal seam gas via injection wells (11); 3. The mixed gas with coal seam gas is acquired in harvesting wells (12) until the methane concentration is lower than the coal mining concentration and the preservation concentration. The invention has the advantages of considering both the competitive absorption of strong replacement gas and the effect of permeation increase and methane gas partial pressure of feeble replacement gas; improving the recovery factor and the single yield of the coal seam gas, and reducing the coal mining cost of the coal seam gas, simultaneously, mothballing the waste gas geologically, and reducing and sealing waste gas at a maximum.

Methods for optimization of liquid oil production by huff-n-puff in shale reservoirs to achieve an improved (and optimal) oil recovery factor. The process determines and utilizes the optimum huff and puff times, number of cycles and soaking time under practical operation and reservoir conditions. The huff time in the process is a period so long that the pressure near the wellbore reaches the set maximum injection pressure during the huff period. The puff time in the process is the time required for the pressure near the wellbore to reach the set minimum production pressure during the puff period. Soaking is typically not necessary during the huff-n-puff gas injection in shale oil reservoirs. The number of huff-n-puff cycles is determinable by the time in which the economic rate cut-off is reached.

Systems and methods for the determination of an optimum salinity type and an optimum salinity of a surfactant microemulsion system are shown. Optimum salinity type and optimum salinity in surfactant/polymer flooding is determined, according to embodiments, by core-flood experiments so that a variety of multiphase flow parameters such as relative permeability and phase trapping that affects oil recovery factor, influences the determination of the optimum salinity type and optimum salinity. The optimum salinity determined from this approach preferably corresponds to the highest oil recovery factor.

A method for estimating minimum miscibility enrichment (MME) for an injectant used in gas flooding of a reservoir at a given operating pressure comprising performing a plurality of slim tube simulations for the reservoir, determining minimum miscibility pressure (MMP) for a plurality of injected gases, creating a plot of recovery factor (RF) vs. 1−(MMP−P)/MMP wherein P is a dimensionless pressure, wherein the plot has having a y-intercept and slope, obtaining a recovery factor equation RF=i+s(1−(MMP−P)/MMP) wherein i is the y-intercept and s is the slope, determining a value for I, determining a value for s and calculating the recovery factor.

The invention relates to an evaluation method of carbonate gas pool reserve utilization conditions. According to the evaluation method, logging information is fully utilized and subjected to multi-element combination to obtain percolation characteristic parameters which are used for evaluating gas pool reserve utilization conditions in a quantitative mode, and the parameters fully consider the lithology, shale content, gas content, permeability, pore structure types and pore structure coefficients of reservoir stratums and can accurately reflect the difference between inter-layer and in-layer percolation ability of carbonate gas pool small layers and the reserve utilization degree. The random modeling means is effectively utilized to set up a three-dimensional percolation characteristic parameter continuous geologic model, so that percolation characteristic parameter inter-well prediction is carried out, the smoothing effect of a traditional interpolation method (like the Kriging method) to parameters is overcome, the anisotropism of carbonate gas pool reservoirs is really reflected, technical support is provided for effective utilization of gas pool reserves, the continuous stable yield foundation of a gas pool is enhanced, and the purpose of improving the ultimate recovery factor of the gas pool is achieved.