733 results about "Heavy oil reservoir" patented technology

The invention relates to a coiled tubing supercritical CO2 jet fracturing method. The method is used for performing jet fracturing on oil well reservoirs by taking supercritical CO2 as fracturing fluid. By the method, a supercritical CO2 fluid is used as the fracturing fluid to perform the jet fracturing; a supercritical CO2 sand jet perforating hole can reduce system pressure; the pressure needed by fissure extension can be further reduced by the characteristics of low viscosity and high dispersion performance of the supercritical CO2 fluid; most importantly, the supercritical CO2 jet fracturing does not pollute the reservoirs, but the supercritical CO2 can further improve the oil and gas recovery ratio after entering the reservoirs; the return discharge is not needed after the fracturing is completed; when the stage-by-stage jet fracturing is performed by using the coiled tubing, a tube pillar can be lifted or put down without mineshaft pressure relieving, the operation process is reduced and the operation cost is reduced, so that the method is extremely suitable for fracturing modification of unconventional oil-gas reservoirs such as thick oil reservoirs, low permeability and super-low permeability oil-gas reservoirs, shale gas reservoirs, coal bed methane reservoirs and the like of which the effects are low by using the conventional water-based fracturing fluid.

The present invention relates to a thermochemistry assistant strengthening steam drive method for thermal recovery of horizontal well using oil-soluble compound viscosity reducer and carbon dioxide. The technique scheme is that: Drilling an horizontal well below the heavy oil reservoir layer, injecting periodically oil-soluble compound viscosity reducer, carbon dioxide liquid and steam in slug injection forms to horizontal well, after shutting in well and opening to blow, continuous oil extraction is operated by the inner lower pump in horizontal well. The present invention can reduce base oil viscosity of super heavy oil reservoir in lower or middle deep layers greatly, reduce steam injection pressure greatly, enhance steam hot wave and range, and enhance period exploitation effect. The scene experiment proves that the average period oil-steam ratio reaches to 0.75, average period oil production is 1800t, the room experiment proves that developing thermochemistry assistant strengthening steam drive in the late period of middle deep layer of super heavy oil reservoir, the final oil reservoir recovery can reach about 40%.

A method for the recovery of upgraded oil from an oil-bearing formation is provided wherein a hot gas phase fluid comprising steam is brought into contact with a heavy oil reservoir, such as by injection, and the hot fluid heats at least a portion of the reservoir to a temperature high enough for steam cracking, and subsequently the steam is reacted with the heavy oil to produce steam cracked lighter oil.

The invention relates to a gravity-assisted steam flooding mining method for exploiting thick-bed ordinary heavy oil reservoirs. In the thick-bed ordinary heavy oil reservoirs, the methods of steam injection in vertical wells and production in horizontal wells or steam injection in horizontal wells and production in horizontal wells are adopted . For the oil reservoir blocks that have been developed by vertical wells, the combination of vertical wells and horizontal wells can be used to drill horizontal production wells along the lower part of the oil layer in the known oil reservoir blocks, so that the vertical steam injection wells are obliquely above the horizontal wells, and the production wells and injection wells Simultaneous huff and puff of steam wells for 2-4 cycles or thermal communication between steam injection wells and production wells or formation of reservoir pressure down to 3-4MPa, transfer to steam injection wells and steam injection production wells for production and production; or steam injection wells and production wells have formed thermal communication , After the newly drilled horizontal production well huffs and puffs for one cycle and removes the pollution near the wellbore, the steam injection production well is transferred to the steam injection well for production and production. The invention can exert the sweeping effect of the displacement fluid in both vertical and horizontal directions, increase the sweeping range of the driving fluid, and increase the crude oil recovery rate of the thick common heavy oil reservoir.

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 relates to the technical field of heavy oil recovery, in particular to a foam agent system used for switching water drive into steam drive of a heavy oil reservoir or steam huff and puff to improve the oil recovery efficiency. According to the technical scheme, the temperature-resistant and salt-tolerant foaming agent system for thermal recovery of the heavy oil reservoir is characterized by comprising a foaming agent base, a foam stabilizer, a foam fixing agent, a foam promoter, an alkali substance, inorganic salt and a solvent. The foaming agent system can resist the temperature of 350 DEG C and has good thermal stability and better foamability; the foaming agent base in the system is lower than the critical micelle concentration and can produce more foam, the apparent viscosity is substantially increased, and the cost is saved; the foaming agent system has better solubility, causes little damage to formation and is environment-friendly.

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 provides a foaming agent for low gas liquid ratio foam flooding for improving recovery ratio of common heavy oil reservoir and an injection method thereof. The foaming agent is prepared from a nonionic-anionic surfactant, a betaine type amphoteric surfactant and water, wherein the nonionic-anionic surfactant accounts for 0.01 to 0.03 weight percent of the total weight; the betaine type amphoteric surfactant accounts for 0.05 to 0.3 weight percent of the total weight; and the balance is oil field injection water. The foaming agent has good foaming tendency, can reduce the interfacial tension of oil and water to the lowest under the condition of not adding alkali, and can give full play to the foam flooding and the improvement of conformance factor and displacement efficiency. On the basis of the foaming agent, when the gas liquid ratio is between 0.1:1 and 0.3:1 (volume ratio), the generated foam can improve the recovery ratio by over 10 percent, and the technology with low cost and good effect for improving the recovery ratio of the heavy oil reservoir is realized.

The invention provides a two-dimensional microcosmic visual thickened oil replacement simulation experiment system and a use method thereof. The two-dimensional microcosmic visual thickened oil replacement simulation experiment system comprises a microcosmic simulation experiment device, a visual data acquisition device, a support device, a multivariate thermal fluid injection device, a confining pressure tracking device and a metering device, wherein the microcosmic simulation experiment device comprises a heating jacket, a clamper and a plate glass microcosmic model; the visual data acquisition device comprises a microscopic shooting device and a computer; the multivariate thermal fluid injection device comprises an ISCO injection pump, an oven and a replacement medium intermediate container, a water intermediate container, a thickened oil intermediate container, a first heat traced pipeline and a bypass pipeline; the confining pressure tracking device comprises an annular pressure tracking pump, an annular pressure tracking pump pressure meter, a vacuum pump and a first vacuum valve. The two-dimensional microcosmic visual thickened oil replacement simulation experiment system give full consideration to characteristics of the thickened oil reservoirs, provides convenience for research on a thickened oil replacement mechanism through microcosmic experiments, has the advantages of low experiment cost, high work efficiency and the like, and can meet with demands on development and research of the thickened oil reservoirs.

The invention discloses an in-situ combustion combustion-supporting ignition method. The method comprises the steps that an electric igniter is tripped in the preset position in an oil tube in a well; air is continuously injected into the well from the oil tube at a first preset speed, and after a liquid level in the well is pressed into a stratum, the electric igniter is started to heat the injected air; after the air is heated by the preset heating time, a power source of the electric igniter is turned off, the electric igniter is taken out, and the air is continuously injected at the first preset speed in the process of taking out the electric igniter; air is injected into the well from the oil tube at a second preset speed, meanwhile, iron pulverized coal is injected, and an oil layer of a heavy oil reservoir is ignited under the action of heat released by combustion of the iron pulverized coal and the air. Through the electric igniter, the oil layer is preheated, and water of near bore zones is reduced. The iron pulverized coal has the functions of profile correction and channeling blocking, combustion products are stored in holes, a gas entry profile continues to be adjusted, ignition is facilitated better, gas channeling is reduced, and meanwhile fast ignition is achieved.

The invention provides an artificial foaming-oil huff and puff oil production method for a heavy oil reservoir. The method comprises the following steps: filling aqueous solution of foaming oil accelerant and nitrogen into the heavy oil reservoir, wherein the foaming oil accelerant comprises a foaming oil accelerant A, a foaming oil accelerant B and a foaming oil accelerant C of which the mass ratio is 1:1:1; soaking for 1 to 5 days; opening a well to produce oil in a certain production differential pressure range and stopping producing oil when the single-well daily oil production reaches single-well economic limit; repeating the step 1 to the step 3 and stopping production until the single-well cyclic oil production reaches cyclic economic limit, wherein the heavy oil reservoir has a reservoir thickness of over 2m, reservoir permeability of over 10*10<-3> mu<m2>, a reservoir temperature of lower than 120 DEG C, viscosity of crude oil of over 50mPas, oil saturation of over 30 percent and water saturation of over 50 percent. According to the artificial foaming-oil huff and puff oil production method for the heavy oil reservoir, which is provided by the invention, the viscosity of crude oil can be reduced and elastic energy of fluid can be increased so as to increase single-well productivity and a recovery ratio of an oil field.

The invention discloses a measuring method of high-temperature oil-water relative permeability of a heavy oil reservoir. A method for replacing high-temperature oil-water relative permeability of the heavy oil reservoir with oil-water relative permeability under the low-temperature oil-water system condition is put forward for the first time, reduces the measuring difficulty of the high-temperature oil-water permeability of the heavy oil reservoir, avoids potential safety hazards caused by high-temperature and high-pressure experiment conditions and simplifies experiment processes and operation requirements, and the oil-water relative permeability obtained with the two measuring methods is basically identical on the premise that the oil-water viscosity ratio is equal, thus, simple, time-saving, safe and accurate measurement of the high-temperature heavy oil relative permeability is realized with the method.

The synergist for steam exploitin thickened oil consists of gas creating agent 10-40 wt%, surfactant 5-25 wt% and alkali 0-5 wt% except water. The preparation process includes the steps of: dissolving sodium hydroxide and/or sodium carbonate; adding surfactant via stirring for mixing and adding the gas creating agent via stirring. Under steam temperature urea as the gas creating agent is decomposed to generate CO2 and CO2 and the surfactant form foam to expand the steam wave and volume to raise the oil displacing efficiency and reach the synergistic effects of modifying profile and lower viscosity obviously. The present invention is suitable for exploiting shallow, thin, dense and dispersed thickened oil reservoir. The present invention can raise oil yield and steam heat efficiency.

The invention relates to a mining method for a heavy oil reservoir and a well network used in the same. The mining method comprises a well network arrangement stage, a preheating stage, a gravity fire flooding stage and a steam flooding stage; the gravity fire flooding stage comprises an ignition stage and a fire wire propulsion stage. The well network comprises a plurality of mining well groups. Each mining well group comprises a horizontal well, a middle vertical well and a plurality of side vertical wells, wherein the plurality of side vertical wells are arranged in two lines; the first line of the side vertical wells and the second line of the side vertical wells are symmetrical about the horizontal well; each line of side vertical wells are arranged at intervals in the direction from the tiptoe to the heel of the horizontal well and are in parallel to the horizontal well. According to the invention, combination of gravity fire flooding and steam flooding is adopted, so that utilization of heat after fire flooding is improved; thermal communication of injection and production wells is established by steam huff and puff auxiliary gravity fire flooding, so that a steam flooring mining effect is improved; well completion cost and drilling cost are reduced.

A high-efficiency pour point depressant for thermal recovery process comprises (1) biphenyl, polycyclic aromatic hydrocarbons or polycyclic aromatic hydrocarbon derivatives free of chlorine and sulfur elements; (2) liquid petroleum products containing arene larger than 5%, petroleum resin in liquid state at normal temperature or natural hydrocarbon aggregates in particle state at normal temperature; (3) surfactant; (4) fusel oil; (5) alcohol ethers having a closed cup flash point larger than 20 DEG C; and (6) oil-soluble or water-soluble polymers respectively having a nonpolar section eutectic with paraffin molecule and a polar section for twisting crystal form of wax crystal on a main chain and/or a branch chain. The high-efficiency pour point depressant of the invention performs all functions of both water-base pour point depressant and oil-base pour point depressant, and can efficiently assist the prior various thermal recovery processes in exploring high pour-point oil and heavy oil reservoirs, with the advantages of greatly reduced exploitation cost, prolonged production cycle of the oil well, increased output of the oil well, increased ultimate recovery of the oil reservoir,as well as significant economic benefit.

The invention provides a gravity and steam flooding combined mining method of a thick layer containing an interlayer common heavy oil reservoir. The method comprises the following steps: 1) whether geological parameters and fluid characteristics in an oil deposit block can satisfy mining conditions or not is ensured; 2) in an interlayer oil deposit block, a straight well and horizontal well combined well spacing mode is adopted, a horizontal producing well is drilled on the lower portion close to an oil layer, a steam injection straight well is arranged diagonally above the horizontal producing well, and a producing straight well is arranged in an area on the same layer with the steam injection straight well according to growing circumstances of the interlayer; 3) huff and puff are conducted simultaneously by the horizontal producing well and the steam injection straight well so that hot communication is formed by the steam injection straight well and the horizontal producing well, the reservoir pressure drops to 3-4MPa, and then steam is injected by the steam injection straight well, and production and mining are conducted by the horizontal producing well; and 4) after the oil layer on the lower portion of the interlayer is put into use basically, perforation is conducted on the parts, arranged on the upper portion of the interlayer, of the steam injection straight well and the producing straight well, steam injection well points are increased and steam quantity is improved at intervals, and production and mining are conducted simultaneously by the horizontal producing well and the producing straight well.

The invention relates to a method for integrally catalyzing, reforming, reducing the viscosity, extracting and conveying thick oil in thick oil deposit extraction, which can reduce the mixing amount of thin oil and lead the separated thick oil to be transported outside after catalyzing, quality improving and viscosity reducing. The method comprises the following steps: mixing thin oil with thick oil in a pitshaft according to the mass ratio of 0.4-1.0 of the thin oil to the thick oil so as to reduce the viscosity of the thick oil; extracting the thick oil mixed with the thin oil from the pitshaft, warming up by a heat exchanger, heating by a heating furnace to 350 DGE C, leading the oil to enter a distilling tower, collecting distillate oil with the temperature being lower than 350 DGE C,cooling the oil by the heat exchanger and filling the thick oil mixed with thin oil into the pitshaft for cycling; conveying heavy distillate oil with the temperature being up to 350 DGE C to the heating furnace by a pump for warming up, adding a reforming catalyst by a pump, and conveying the mixture to a reaction tower; catalyzing and reforming the heavy distillate oil into thick oil with low viscosity under the action of the reforming catalyst, and directly transporting the reformed thick oil outside after heat exchange. The thin oil mixed by the method can be cycled, and separating the thick oil from the thin oil does not damage the characteristics of oil. The method which has wide application range and favorable viscosity reduction effect and enables the quality of thick oil to be improved is used for thick oil extraction.

The invention discloses an oil extraction method for extracting raw oil in a horizontal well. The oil extraction method comprises the steps of: A, fracturing the horizontal well; and B, performing horizontal well fireflood assisted gravity drainage on the fractured horizontal well. According to the oil extraction method, the fracturing technology is combined with the single horizontal well fireflood assisted gravity drainage extraction technology, the double advantages of horizontal crack leading fireflood front edge expansion and gravity assisted drainage are made full use of, and a thick oil deposit with an oil layer thickness of more than 4m can be economically and effectively developed.

The invention belongs to the technical field of fire flooding oil extraction and in particular relates to a thick oil reservoir fire flooding oil extraction combustion-supporting ignition method. The method is implemented by the following steps of: (1) building an injection well on the conventional well network and a plurality of production wells at the periphery of the conventional well network according to oil layer geological information to form an area well network or a row-line type well network, wherein in the row-line type well network, one well row is the injection well and the adjacent well rows are the production wells; (2) injecting high-temperature steam with equivalent weight of 250 to 300 cubic meters of water into the injection well in the step (1) and preheating a ground layer to 210 to 250 DEG C; and (3) at the later stage of injecting the steam, mixing a combustion improver and crude oil according to the weight ratio of the combustion improver to the crude oil of 8.5 to 11.6 percent, injecting the mixture into the ground layer together with the high-temperature steam, and then continuously injecting sufficient air. By the method, the threshold temperature of high-temperature oxidation of the crude oil is greatly reduced and oil is easy to ignite; ignition is easy to implement; the ignition time is shortened; the ignition success rate is high; and construction is performed conveniently.

The invention relates to a propane-injecting shallow heavy oil reservoir exploitation method. The propane-injecting shallow heavy oil reservoir exploitation method includes the following steps: a horizontal injection and production well network is arranged in a shallow heavy oil reservoir exploitation area, an injection well and a production well are arranged in the oil layers at the same vertical plane position to form an injection and production well pair, the injection well is a horizontal injection well, the production well is a horizontal production well, and the horizontal injection and production well network comprises at least one injection and production well pair; injected steam circulation preheating is carried out simultaneously via the injection well and the production well; after the temperature of the oil layer between the horizontal section of the injection well and the horizontal section of the production well is increased to a predetermined temperature, the injection well and the production well simultaneously stop circulation preheating, propane starts to be continuously injected into the injection well, and the amount of the injected propane is 5000m3/d to 25000m3/d; and the production well starts continuous oil production. The propane-injecting shallow heavy oil reservoir exploitation method has the characteristics of high recovery rate, propane recycling, low exploitation cost, high economic benefit, low energy consumption, low emission, environment-friendliness and the like, and is easy and safe to operate.

The invention is a method for multi-well cyclic steam stimulation thickened oil recovery by thermal recovery-steam injection technique, selecting: oil-layer depth in oil reservoir<1800m, residual oil saturation > 0.40, total oil-layer thickness > 5.0m, net-total thickness ratio >0.4, oil-layer porosity >0.15, and permeation rate variation coefficient <0.8; placing adjacent steam channeling wells and steam channeled wells (above two) together in the same group, simultaneously making steam injection in the well drainage sequence or block cluster well sequence, where steam injection strength of single well is 50-200 cu m/m and the well-bottom dryness fraction is greater than 50%, then stewing them, and finally opening them for production in the same sequence as above-mentioned. It can prevent steam channeling and interference between wells, effectively supplements pressure energy to oil layers and helps enlarge the steam spread range, and can increase the oil-layer pressure by about 2MPa as compared with single well steam stimulation method. It can both increase single-well output and prolong the life of steam stimulation.

The invention discloses a method of oil pumping which adopts the combination of fire oil layer slug and steam drive and is applicable for the pumping of thick oil reservoir. After the steam soaking of the thick oil reservoir and before the pumping of the steam drive, the fire oil layer slug type pumping is performed; an ignition technology is adopted to ignite the oil layer to burn; an air compressor is used to inject air into the oil layer continuously from a center injection well; after 0.3 to 0.8 years of pumping, steam is injected into the oil layer through an injection well, and the steam drive type pumping is performed. The invention can generate the high temperature of 400 to 800 DEG C in the burning zone of the fire oil layer slug, which is in favor of the water stored in an individual well after the steam soaking to be vaporized as high-dryness steam; the temperature of the bottom of the injection well, and the dryness of the steam injected by the following steam drive are improved; the strata pressure is improved; larger producing pressure differential is achieved, which is in favor of improving the lifting rate of the oil well; moreover, the invention is in favor of shortening the low-production period at the beginning period of the steam drive and improving the developing effects of the steam drive and the recovery ratio of crude oil.