CN1012091B

CN1012091B - Steam enhanced oil recovery method using branched alkyl aromatic sulforates

Info

Publication number: CN1012091B
Application number: CN 88103174
Authority: CN
Inventors: 罗伯特·G·沃尔; 弗兰科西斯·弗雷得安; 斯蒂文·P·科伦特
Original assignee: Chevron Research Co
Current assignee: Chevron USA Inc
Priority date: 1987-05-28
Filing date: 1988-05-28
Publication date: 1991-03-20
Also published as: GB8812372D0; CN1030118A; CA1330256C; GB2205122A; GB2205122B

Abstract

A method of enhanced oil recovery using foam to improve the effectiveness of steam to mobilize viscous crude, either for steam stimulation in a single well or for steam drive between wells. A new surfactant composition having branched alkyl aromatic sulfonates as the effective agent for the steam foamer is used because of its ability to foam in the presence of substantial pore volumes of residual oil and thereby mobilize significant amounts of producible oil by diverting steam to less-permeable zones.

Description

Steam enhanced oil recovery method using branched alkyl aromatic sulforates

The present invention relates to improve the oil recovery factor of oil reservoir, particularly relate to lathering surfactant is injected oil reservoir with steam or gas through injecting well, improve the method that steam or gas stimulate or drive crude oil.

Foundation of the present invention is that steam or gas and surfactant can interact in the stratum with formation fluid, produces foam.Foam trends towards shutoff easily makes steam or gas be gas or steam channel that " fingering " or " gravity segregation " flows into the high osmosis on stratum.In the steam flooding engineering, in the passage of high osmosis steam overlap fluxion strap or isolation, the saturation ratio of residual oil (Sor) usually is lower than 15% late.In these cases, always wishing that steam is turned to by the low permeability channel of oil saturation enters the high low permeability layer band of oil saturation.Best lathering surfactant can produce foam in these cases, stops steam to flow into the layer band of crude oil exhaustion, and can not bubble and block the layer band that steam enters the saturated height of oil-containing.A kind of surfactant example with these characteristics is by 4,556, and No. 107 United States Patent (USP) proposes.Under the other situation,, find that perhaps the crude oil saturation ratio of upper layer band is higher than the situation of crude oil saturation ratio in the steam flooding engineering in late period because the gravity drainage effect permeability channel occurs by the saturated again situation of crude oil.In these cases, for mobility control and the raising oil recovery factor that improves steam, wish to use a kind of surfactant that can under two kinds of situations of higher oil saturation, produce foam again at low oil saturation.Therefore, The present invention be more particularly directed to improve the shutoff problem of residual oil content than higher gas or vapour permeability passage, used surfactant can not only preferentially produce foam in the passage of crude oil exhaustion, and can also residual oil saturation be 15% or higher stratum in produce foam.The foam of Chan Shenging can provide the steam mobility control and improve the oil recovery factor of permeability interlayer like this, also can make the area of steam around entering simultaneously, increase the flowability of crude oil and on every side the stratum be rich in oil oil recovery factor partly.

A kind of preferred form of Efferescent compositions is a kind of surfactant solution, it contains a kind of branched alkyl aromatic series surface active agent composition, this surfactant has at least one branched alkyl that 15～30 carbon atoms are arranged, described alkyl have at least three secondary carbons and (or) tertiary carbon atom.Described branched alkyl aromatic sulphonate component also can contain 0-2 the positive alkyl substituent that 0-3 carbon atom arranged.In another preferred version, this solution contains a kind of branched alkyl aromatic sulphonate component and (1) a kind of alhpa olefin sulfonate dimer component, or (2) a kind of sodium metasilicate component, or (3) a kind of sodium chloride component, or the mixture of (1), (2), (3).Have the excellent reaction time by these compositions of the present invention's preparation are verified, can produce foam effectively, shutoff and promotion crude oil are by containing the rock core of abundant residues oil.

Specific purpose of the present invention is with the form of the aqueous solution surface activator composition that produces foam to be injected oil reservoir, it can have gas of shutoff high osmosis very effectively or steam channel under the oily situation about existing of abundant residues, this Efferescent compositions can not only promote residual oil and move in shutoff oil reservoir gas high osmosis part, and can enlarge hypotonicity that steam or gas and oil reservoir be rich in crude oil contacting partly effectively.

From qualitative angle, this new surface activator composition comprises a kind of surface active agent composition that produces foam, the selection of this surface active agent composition is because contain in existence under the situation of the gas of some water and residual oil at least or steam, as frother, it has very high validity.A kind of preferred form is the alkyl aromatic sulfonate that the surfactant solution of injection contains a kind of highly branched chain, it has and is at least about 400 molecular weight (being generally 400-600), can produce foam well and steam is implemented mobility control in the permeability channel that contains water and appreciable amount residual oil.As want under reservoir condition, to make foam have persistence, before inject producing each component of foam can steam add such as nitrogen, carbon monoxide gas or methane gas can not be condensing gas.

The steam stimulation of oil reservoir or oil reservoir is one of method of the preferential raising oil recovery factor that adopts.This is because steam can provide heat for low severe high viscosity oil cost-effectively.Heat can reduce crude oil flows to producing well from oil reservoir resistance in very wide reservoir permeability scope.And steam injection can improve the natural pressure of oil reservoir like this, because the effect of hydrostatic head or the degree of depth-barometric gradient, can increase the pressure differential between the crude oil and producing well pit shaft in the oil reservoir.

Producing well can be the same well (being commonly called as steam " handles up ") that regular steam injection stimulates reservoir oil stream.Another kind of mode is to arrange flatly or more mouthfuls of producing wells near injecting well flatly, so that the steam drive crude oil that injects flows to a bite producing well at least by oil reservoir.

The stratum of nearly all formation oil reservoir all is a sedimentary rock, and its rock matrix is subsequently through overcompaction or crystallization.These have the different very long geochronic clast sedimentary rocks of forming of process is to form with different speed depositions.The rock that stores oil after compacting is infiltrative, but in general runner is very inhomogeneous.In view of the above, the oil reservoir that forms by this rock stratum, though with regard to it to original (primary) or the fluid that injects, aspect two of degree of porosity and permeabilities, all be heterogeneous body originally.And for original gas, crude oil and water, wherein the permeability of each fluid or its mixture also is very inequality.Owing to there are these difference on permeability, present common practices is to inject the surfactant that produces foam with steam, so that the passage to the easier infiltration of gas that shutoff may develop in the stratum.To be steam by the passage of the easier infiltration of gas turn to the result that reaches of expectation flows into the low permeability layer band that is rich in crude oil in the oil reservoir.Produce the normally organic surfactant materials of component of foam.

Another characteristics of this non-homogeneity of sedimentary type formations are wherein to contain shale or clay.As everybody knows, such clay material particularly when the water that injects with vapor form is fresh water, very easily changes when contacting with water.Usually, clay has big surface/volume, meeting water or steam after changing, contacting between original crude oil and the reservoir rocks is trended towards producing adverse influence.Especially contain the sticking oil reservoir that has machine metal and acidic components, all responsive especially to the steam and the surfactant materials that are used for improving oil recovery factor.And the solubility of surfactant in stratum connate water and oil reservoir crude oil may produce injurious effects to the ability of generation foam or the stability of foam owing to fingering or the mobile place that gas permeability and vapour losses amount are increased of gas onlap.Therefore, in the place of permeability channel residual oil saturation above a few percent voids volume, foam may lose efficacy.So, generation foam when just needing the lathering surfactant composition preferably can be in the steam on stratum or water permeability passage or around it contact with residual oil, and when with oil reservoir in be rich in and do not produce a large amount of foams when crude oil in the runner of crude oil contacts.

The present invention is a kind of improvement that former application Efferescent compositions is improved the method for oil reservoir crude output.The many methods that adopt Efferescent compositions are mentioned in No. 964 United States Patent (USP)s, and are discussed 4,086.Other relevant patent comprises United States Patent (USP) 4,393,937,4,532,993 and 4,161,217.The present invention also is a kind of improvement for the previously known method of controlling " fingering " or " onlap flow " with the formation foam.These methods are to inject a kind of surfactant that produces foam in company with gas or steam, generation foam when the residual oil that causes when gas or steam flow channel in surfactant and the oil reservoir partly contacts.

Need know considerable time in that the surfactant that produces foam under the simultaneous situation of You Heshui is arranged.Bernard (Bernard) (" foam is to the influence of gas drive oil recovery factor ", the secondary oil recovery monthly magazine, 1963,27 volumes, the 1st phase, the 18-21 page or leaf) pointing out, be used for the surfactant such as the best generation foam of this class non-phase-mixing driving of steam flooding, is the surfactant that can produce foam when having oil and water to exist simultaneously.Deere Glenn (Dilgren) etc. (4,086, No. 964 United States Patent (USP)s) having recognized can not condensing gas and add importance such as sodium chloride electrolysis confrontation steam bubble, and finds can use alkyl aromatic sulfonate, i.e. dodecyl benzene sulfonate to steam flooding.Alkyl aromatic sulfonate is used in other patent suggestion for this reason, but does not recognize branched structure and the linear chain structure difference (4,532,993,4,161,217 and 3,348, No. 611 United States Patent (USP)s) on characteristic.4,161, No. 217 United States Patent (USP) is thought, the mixture of the alkyl aromatic sulfonate of low-molecular-weight (300-400) and HMW (400-600) can not condensing gas foam flooding be useful frother for hot water.The patent of one piece of renewal (4,562, No. 727 United States Patent (USP)s) thinks, is a bigger improvement to alkyl aromatic sulfonate such as the alkene sulfonate of this class of alhpa olefin sulfonate.The present invention finds a class branched alkyl aromatic sulphonate, and they are compared with the surfactant that proposes in the past, and significant superiority is arranged, and all can produce foam better under different remaining oil mass situations.It is particularly useful that this class surfactant is used for improving the oil recovery factor of such class oil reservoir: the high osmosis layer band of this oil reservoir contains the remaining oil mass that changes, and the excursion of its saturation ratio is by a few percent to 30% of voids volume or higher.

The present invention proposes the method for the steam flooding of a kind of surface activator composition and a kind of improvement for crude oil to the oil recovery factor that improves oil reservoir with steam.Comprise in company with steam and inject a kind of surface activator composition in oil reservoir, this surface activator composition can exist under the remaining oil condition in injection period, perhaps in the part of oil reservoir crude oil exhaustion, interacted with steam generation, formed foam.Best, steam is the moist steam of part at least, to help forming foam when contacting with residual oil.

A kind of preferred form of foam compositions is a kind of surfactant solution, contain: (1) a kind of branched alkyl aromatic series surface active agent composition, molecular weight is at least 400(and is generally 400-600), wherein at least one alkyl contains 15～30 carbon atoms, described alkyl contain at least three tertiary carbon atoms and (or) secondary carbon.The another kind of preferred form of surface activator composition is (1) and (2), i.e. second kind of anion surfactant component, mixture as alhpa olefin sulfonate or alhpa olefin sulfonate dimer component, or with (3), be the mixture of electrolyte such as sodium chloride or sodium metasilicate component, or the mixture of (1) and (2) and (3).Has an excellent combined characteristic according to the surface activator composition of the present invention preparation is verified, comprising fast reaction and under the situation that has various quantity residual oils to exist, form the foam of strong stability.Surface activator composition preferably joins in the steam with the form of the aqueous solution, the water of steam contain about 0.01-5% alkyl aromatic sulfonate and (or) second kind of anion surfactant component of 0.01-5% and (or) the 0.01-5% electrolyte.In an advantageous embodiment, said components (1) is 1: 10～10 with the ratio of (2): 1(weight); And two kinds of components are 0.1-10%(weight in the concentration of aqueous phase).

The most preferred form of foaming component is a kind of alkyl aromatic sulfonate, it is a kind of alkyl aromatic sulfonate of highly branched chain preferably, and as previously mentioned, its molecular weight is at least 400, and it can the aqueous solution form or the form of moist steam additive, inject producing zone off and on or continuously.This branched alkyl aromatic sulphonate can with the vapor phase mutual effect of injecting, mainly have residual oil partly to form foam, shutoff or promote residue in this permeability passage at oil reservoir.

The preferred form of this highly branched chain alkyl aromatic sulfonate is the branched alkyl that 15～30 carbon atoms are arranged, and each alkyl all is connected on the aromatised fraction (preferably benzene, toluene or dimethylbenzene), and the sulfonate component is connected on the aromatic rings.Alkyl aromatic sulfonate can use conventional experiment or commercial-scale method of sulfonating to be prepared by the branched alkyl aromatised fraction.And branched alkyl aromatic hydrocarbon can make the alkylating method preparation of aromatised fraction with branched-chain alkene.Suitably the branched-chain alkene of molecular weight can be used the olefin oligomerization method, as with suitable catalyst action in propylene production.Be applicable to that catalyzing propone oligomerization process of the present invention is phosphoric acid or the boron trifluoride catalytic oligomerization that everybody is familiar with.3,932, No. 553 United States Patent (USP)s provide the example of the oligomerization process that is suitable for.

Sulfonate is fit to form, particularly sodium salt, sylvite, ammonium salt or other the water miscible cation salt with salt.Sodium salt preferably.Yet also can use the sulfonate of sour form in the present invention.

Except that surface activator composition, in steam, can also add have the property annotated can not be condensing gas.Wish to do like this, but be not to do like this.Gas component that can not be condensing can be injected continuously or at least regularly inject in company with steam.Generally speaking, the gas phase of steam can contain 1-50% can not be condensing gas.And gas can be mixed phase in the oil phase of reservoir fluid.This class gas can be nitrogen, methane gas, flue gas, carbon dioxide gas, carbon monoxide gas or air.In addition, steam and surface activator composition can inject a bite well continuously, and from the contiguous well that same oil reservoir is got, recovering the oil.Perhaps, the steam cycle of containing Efferescent compositions is injected a bite well, and from same well, regularly recover the oil.

Further aim of the present invention and advantage will become more obvious from the detailed description below in conjunction with accompanying drawing.These accompanying drawings are ingredients of this manual.

Fig. 1 is that a bite of passing the oil reservoir that is formed by sedimentary type formations is injected well steam in jection and the diagram that contains the surface activator composition of foaming component.

Fig. 2 is the schematic flow sheet that produces the experimental layout of foam under the simultaneous situation of the You Heshui that represents oil reservoir Central Plains to come fluid having.Flow through the permeability rock core after wherein foam forms, so that can estimate the validity of surfactant extraction or that the have residual oil substantially vapour permeability runner of shutoff crude oil in annotating the rock core of water that produces this foam, and measure that it forms the resistance of foam in rock core under different liquid conditions.

Fig. 3 is the curve map with the experimental result of Fig. 2 experimental layout acquisition, an ingredient of surface-active compositions evaluation method is described, promptly estimates the situation soffit surfactant composition that in rock core, has residual oil and salt solution simultaneously and form the ability of foam and the stability of the foam that forms.

The present invention to small part be the following foundation that is found to be, promptly use a kind of composition of matter, comprising using specific branched alkyl aromatic sulphonate surface active agent composition, inject oil reservoir, it can more effectively produce foam than known surface activator composition existing under the steam situation, and promote residual oil in the gas permeability passage, thereby obtain non-obvious, but very useful effect.To be it contain residual oil and the shared percentage of gas or steam forms the excellent ability of foam much larger than the place of other parts of oil reservoir in the runner major part to the basic characteristics of this composition of matter.Using this composition results in the engineering of steam flooding raising oil recovery factor is, the high osmosis interlayer that contains in the abundant residues oil passage can preferentially be stopped up by foam effectively.Therefore, residual oil can be pushed and be moved through passage effectively.This preferential ponding of foam can make vapor stream or air communication cross the low permeability layer band that diverticulation flows to high oil saturation.In view of the above, will find; This method has useful effect to the oil recovery factor that improves oil reservoir: owing to can form foam quickly under the situation that has abundant residues oil to exist, it is mobile that steam or gas are turned to from the exhausted substantially layer band of the crude oil that has more gas permeability, thereby can increase that oil reservoir be rich in crude oil with the gas of less amount but the oil of the low layer band of permeability flows.

Fig. 1 schematically illustrates the device layout of injecting lathering surfactant composition of the present invention to local at least depleted oil reservoir.Injecting surface activator composition is the permeability that expectation reduces steam or gas.Just as already noted, specific purpose of the present invention is intended to solve the problem of controlledly steam being injected producing zone, so that heating in crude oil, thereby reduce its viscosity.Steam injection can also increase the pressure in the stratum, improves natural-gas pressure or strata pressure, thereby increases the oil flow that flows into the contiguous well of a bite or same payzone.For this purpose, steam generator 10 utilizes combustion gas or the continuous boiler tube 12 of oil burner 13 heating one way, makes water wherein become steam.The water that generation steam is used is supplied with by pump 34.This water generally contains mineral and salt, can be mixed with the connate water in the stratum or with its uranium compatibility be arranged.Preferably make water pass through " water demineralizer " or Ion Exchange Medium 14, and heating in boiler tube 12, make it to be enough to generate low steam mass dryness fraction or " wetting ", preferably mass dryness fraction is less than 80% moist steam.Such steam injects well 16 through well head 38, subsequently in the injection string 18 after by heat interchanger 15 and steam pipe line 36.Sleeve pipe 17 is arranged under in the well, during tubing string 18 is looked for by centralizer 20 in sleeve pipe, with avoid along the whole length of pipe box with the thermal loss of steam to around the stratum in, thereby steam is annotated the desirable degree of depth, promptly form the stratum 22 of oil reservoir.

The sedimentary type formations of nearly all formation oil reservoir is as 22, and its permeability is water, gentle the flowing of oil for original fluid, is exactly heterogeneous originally.Wherein each fluid all optionally trends towards flowing in to the permeability passage of its resistance minimum.The resistance that every kind of fluid is flowed mainly depend on viscosity that it is independent or its with the mixing mutually of other fluids in viscosity.In general, in each stratum, runner finally forms each fluid or relative permeability is different.Because gas is than oil or water, or other mixture has more flowability, and the steam of injection generally trends towards flowing through and has more infiltrative gas passage, and may form " fingering " 26 in stratum 22, as schemes shown in the short-and-medium stroke of dotted line.This air-flow is walked around more the layer band of " densification " or hypotonicity, and the permeability passage of oil is smaller in these layers band, and oil more closely is strapped on the rock surface in other words.Particularly crude oil also contacts with clay or shale material except that with sandstone that forms the permeability passage or carbonate rock contact.Like this, " fingering " development shown in passage 26, or produces " the gas onlap flows ", shown in the area 25 at 22 tops, stratum.When these situations took place, energy incurred loss, and most of petroleum liquid is subjected to the heating less than steam in jection.Because steam mainly flows by

gas passage

25 and 26, injection profile produces distortion, generally draws shown in the dotted line 28 as short.

As discussed above, the distortion of injection profile can use the component that adds the generation foams at steam injection pipeline 36 to correct.For this purpose, can supply with surfactant solutions by measuring pump 35 and injection pipeline 37 by storage tank 30 and 31.Foam produces in the stratum: perhaps gas in the steam suppling tube line or steam produce, and produce when perhaps contacting with formation fluid.The foam of Zhu Ruing preferentially flows into

gas permeability passage

25 and 26 with steam like this.It can temporarily block these passages effectively, thereby makes the steam in the stratum turn to the part that is rich in oil that heats the stratum subsequently.Ideal results is that steam-front is similar to propelling in the form of piston, shown in dotted line 24.

Yet, contain the appreciable amount residual oil, promptly residual oil saturation surpasses and to form in those steam of a few percent or the gas permeability passage and keep foam, play the effect of sealing agent, is difficulty especially.Have been found that particularly known surfactant is invalid in the oil reservoir of residual oil saturation greater than a few percent.

According to the present invention, the inventor finds, and is higher at the shared percentage of this residual oil saturation, even reaches under 30% or the higher situation of voids volume, and the branched alkyl aromatic sulphonate still can produce foam very effectively.

In the explanation of this example, the certainly contiguous producing well of crude oil is as 52 extraction of 50 usefulness oil well pumps.Obviously, also can regularly recover the oil from injecting well 16 by tubing string 18 then with the heating of steam cycle in stratum 22.To reequip well head 38 for this reason, make it to be similar to and use tubing string 53 suspension pumps 52 such in the well 50, can hang oil rig.

According to the surface activator composition of the present invention preparation, preferably supply with the form of liquid solution, pump with the foaming concentrate from storage tank 30, and with can mix from storage tank 31 with the water of oil reservoir compatibility.The solution that mixes is with pump 35 meterings, contacts with steam mobile in desired speed and pipeline 36 or the tubing string 18 by pipeline 37.In addition, also can form foam with gas from the source of the gas (not shown).The gas that is suitable for comprises nitrogen, flue gas, methane gas, carbon dioxide gas, carbon monoxide gas or air.This gas can add by well head like that with image tube line 36.

Fig. 2 schematically illustrates experimental facilities.This device is used for estimating steam/foam surface activity agent composition and the compatibility of foaming component in containing varying number residual oil rock core thereof, so that estimate its formation and keep foam, the validity of shutoff vapor stream or air-flow.In this example, with the rock sample or the rock core of steel wool artificial core 60 simulation permeability oil reservoirs.Such rock core is contained in tripping container or the transparent high-pressure bottle 57, rock core is under reservoir temperature (as heating with heater coil 61) and the pressure.The fluid that flows into can be by preheater 55 heating.Can pass through source of the gas 63, as nitrogen, pressurization.Heating-up temperature can reach 300 °F to 500 °F, and applied pressure can reach 1000 pounds/inch ²Under suitable flox condition, optionally give the rock core accommodating fluid then.Experimental facilities has a steam generator water-supply source, i.e. the salt water storage tank of being controlled by valve 79 66.Crude oil in the storage tank 65 is by valve 75 and pipeline 68 supply pumps 67.Indifferent gas such as nitrogen flow through experiment rock core 60 from gas tank 63 under control valve 82 controls, its flow can be by flow meter 83 meterings.As shown in the figure, these fluid sources are used for simulating the oil reservoir salt solution and the crude oil of the oil reservoir of studying.Crude oil and salt solution all play the displacement fluid.Selected surfactant solution is in jar 64 salt solution that are added to from jar 66, and its mixture is supplied with rock core by pump 80 pressurizations by preheater 55.By selected addition surfactant materials is introduced experimental system by jar 64 by valve 78.The pressure reduction at rock core two ends is measured by difference batchmeter 59, and difference gauge measuring device two ends are connected on suction line 62 and the outlet line 76.Detected pressure reduction preferably by recorder 72 by time-form of pressure dependence curve notes, as shown in Figure 3.Amount of inert gas is by 73 meterings of humidity check batchmeter, and batchmeter is connected on the knockout drum 74.

Steam-foam experiment

Steam-foam experiment comprises that record is by difference gauge measuring device 59 detected pressure reduction and time relation curve.Selected lathering surfactant flows through the steel wool artificial core plug 60 in the high-pressure bottle 57, and this operation is preferably under the situation that nitrogen stream exists, 400 temperature and 500 pounds/inch ²Carry out under the pressure.

A typical experimental sequence illustrates in Fig. 3.The first step be make from the feedwater of the steam generator of brine tank 66 and from the crude oil of the representative oil reservoir of storage tank 65 together by rock core 60, till recording basicly stable pressure reduction and time curve.Then, as shown in Figure 3, only make the steam generator feedwater by rock core, till setting up stable state once more.Make foam maker be in " residual oil " state this moment.Pressure differential is generally 0-2 pound/inch under these conditions ²

Then the surface activator composition of experiment is pumped into experimental system from jar 64, this moment, surface activator composition was the dilute solution state in the steam generator feedwater.When the quality of Efferescent compositions was good, the pressure differential of steel wool artificial core 60 2 ends increased in 15-100 minute, and stopped to increase when reaching a new steady state value and (be generally 20-100 pound/inch ²); This state is represented with the part that indicates foam pressure poor (Pf) on Fig. 3 relation curve.Then, make crude oil enter experimental system, proceed experiment with surface activator composition.The pressure differential that records under these conditions is generally 2-20 pound/inch ²(Pf+0).At last, replace surfactant solution, measure the pressure differential (Pb+0) that salt solution and residual oil flow through rock core with salt solution (steam generator feedwater).Measured four characterisitic parameters altogether: (1) foam reaches the needed time of steady state pressure difference (reaction time); (2) pressure differential of the stable state of foam (Pf); (3) pressure differential of the stable state of foam+crude oil (Pf+0); (4) pressure differential (Pb+0) of the stable state of salt solution (steam generator feedwater)+crude oil.These characterisitic parameters all mark in Fig. 3.In the low place of residual oil saturation, Pf value big (Fig. 3), the Pf+0 value is little, and this is desirable just.Surface activator composition with these characteristics can enter the still very high part of oil reservoir oil content thereby steam is turned in the flow resistance of the low high osmosis layer band increase steam of oil reservoir residual oil saturation.This just as shown in Figure 1 gravity segregation flow or the typical case of steamchanneling.

Reaction time among Fig. 3 and foam pressure (Pf) depend on the residual oil in surfactant and the foam maker (rock core).Under the situation that does not have residual oil to exist, the reaction time is very short, and lathering surfactant one increases immediately with the foam maker contact pressure.When residual oil existed, reaction time and Pf depended on the significant degree of surfactant promotion and displacement crude oil and are having oily existence condition soffit activating agent to produce the quality of foam ability.The lathering surfactant of once having used prior art in steam flooding is to tackle the onlap mobility status of low remaining oil mass, and its dynamic characteristic as shown in Figure 3.The pressure differential of foam+crude oil (Pf+0) is than only frothy pressure differential (Pf) is much lower, and is also lower than the pressure differential (Pb+0) of salt solution+crude oil, perhaps similar, and this shows under the situation that has oil to exist and does not produce foam.When having the permeability channel of oil-containing owing to the gravity drainage effect, perhaps when the residual oil saturation of onlap fluxion strap is higher than the residual oil saturation of finding in the steam flooding in late period, for these situations, best dynamic characteristic is and the reaction speed of residual oil fast (reaction time is short among Fig. 3), the pressure differential of foam (Pf) height, foam add pressure differential also quite high (Pf+0) height of low discharge crude oil).

Amazingly be, we find that a class surfactant has the favourable combination of these characteristics, comprising: fast with the reaction speed of residual oil, the pressure differential of foam (Pf) height, the pressure differential of foam+crude oil (Pf+0) is higher than the pressure differential (Pb+0) of salt solution+crude oil.These surfactants have following superiority: at onlap flox condition and low residual oil saturation layer band, and in the high permeability channel of residual oil content, can improve steam and turn to and the steam mobility control.Demonstrate these characteristics below.

The characteristic of the foam maker that uses in above-mentioned steam-foam experiment can change with the time that the steel wool artificial core is put, and perhaps changed owing to changing.Will make the parameter of measuring in this experiment continuous changing value occur like this, thereby be difficult to contrast the absolute value between the different surfaces activating agent.Just because of this reason, on experimental facilities, experimentize on a specified date with the good a kind of standard composition of known performance, other surfactant also on the same day with artificial core experiment, note experimental result, and compare with the result of this standard composition.The repdocutbility that relative foam blocking and reaction time measure is usually in 10%.

Example

Contrasted surfactant with above-described experimental facilities (illustrating) test with Fig. 3.The foam flowing experiment is 400 temperature and about 500 pounds/inch ²The following steel wool foam maker with 1/4 inch of diameter, 21/2 inch of length of pressure carries out.The liquid flow of surfactant during experiment is 2 ml/min, and active principle concentration is approximately 0.5%(weight).Gas phase is made up of the steam and the nitrogen of cardinal principle equivalent, and its mixture flow rate is approximately 40 ml/min under experiment condition.Carrying out crude oil flow when experiment, the flow of surfactant or steam generator feedwater is 2 ml/min, and Kern River(gram is thought the river) flow of crude oil is 0.2 ml/min.Salt solution, promptly manually synthetic steam generator feedwater is a dissolving NaCl(295 milliliter grams per liter in distilled water), the KCl(11 mg/litre) NaHCO ₃(334 mg/litre) and Na ₂SO ₄(61 mg/litre) is mixed with.Use following abbreviation in the example below:

The LABS linear alkylbenzene sulfonate (LAS)

LATS straight chained alkyl toluene fulfonate

LAXS alkyl xylene in linear chain sulfonate

The BABS branch-alkylbenzene sulfonate

BATS branched alkyl toluene fulfonate

BAXS branched alkyl xylenesulfonate

BACS branched alkyl cumene sulfonate

Example 1

In this example, the characteristic of the representational surfactant of the present invention and the surfactant of having used or consider to be used for steam-foam flooding are contrasted.In table 1, reaction speed and foam pressure (Pf) have been provided relative value, and the ratio of Pf+0/Pb+0 has been provided absolute value.Obtain relative reaction speed with the inverse in reaction time among Fig. 3.

These results show that branched alkyl aromatic sulphonate of the present invention has the best of breed of each value of desired characteristic, comprising: reaction speed fast (far above 1); Foam pressure (Pf) high (being about 1); The ratio height (much larger than 1) of the pressure (Pb+0) of the pressure of foam+crude oil (Pf+0) and salt solution+crude oil.

Table 1

Relative value

Surfactant reaction speed P _fP _F+0∠ P _B+0

Suntech ^TMIV 1015 1 1 0.1

Chaser ^TMSD1000 2 1 0.1

Enordet ^TM1618AOS 0.7 0.5 0.4

Enordet ^TMLXS 1314 1 0.1 0.2

Enordet ^TMLTS 18 6 1 0.2

COR ^TM180 0.3 0.6 0.7

Dowfax ^TM2A1 0.5 0.5 1

Dowfax ^TM3B2 1.8 0.5 0.6

BATS（457） ¹6 0.9 8.5

BAXS（470） ¹8 1 4.3

BABS（504） ¹4 1.3 3.1

(1) average of equivalent

Embodiment 2

Experiment is undertaken by example 1.These results show that branched alkyl aromatic sulphonate of the present invention is compared with straight chained alkyl aromatic sulphonate or low equivalent branched alkyl aromatic sulphonate, has the best of breed of desired characteristic.

Example 3

Experiment is undertaken by example 1.In these cases, except that main surfactant, also be added with additive, i.e. electrolyte or anion surfactant.

Table 3

Relative value

Surfactant equivalent additive reaction speed P _fP _F+o/ P _B+o

BATS 425 1% NaCl 5.4 0.9 18 ^（4）

BATS 425 0.5%Na ₂SO ₄2.7 0.9 2.7

BATS 425 0.5%SMS ^（1）4.4 0.9 2.9

BATS 471 0.5%NaCl 7 0.9 1.6

BABS 504 0.5%NaCl 6 1.1 5 ^（4）

BATS（0.25%）（3） 457 AOSD ^（2）（0.25%） 3.8 0.9 1.4

BATS（0.25%）（3） 521 AOSD ^（2）（0.25%） 3 1 2.4

BATS（0.25%）（3） 521 2024AOS（0.25%） 3.8 1 1.5

LATS（0.25%）（3） 457 AOSD ^（2）（0.25%） 0.8 0.8 1

(1) SMS is a sodium metasilicate;

(2) AOSD is the alhpa olefin dimer surfactant of 4,556, No. 107 United States Patent (USP) descriptions;

(3) each combinations-of surfactants is a 0.25%(weight in these cases);

Single in all other circumstances kind of surfactant is a 0.5%(weight);

(4) be the pressure of foam+crude oil here.

The presentation of results of example 3, branched alkyl aromatic sulphonate of the present invention is under the situation that has electrolyte or other anion surfactants to exist, and reaction speed is fast, foam pressure (Pf) height, the ratio height of Pf+0/Pb+0.Notice that the LATS/AOSD(that does not belong to the scope of the invention goes up and shows last), the value that three desirable characteristics are provided is not high.

Best, the sulfonate component form of sodium salt.Other salt, as sylvite, ammonium salt or other water-soluble cationics and composition thereof also can use.In addition, in the branched alkyl aromatic sulphonate, sulfonate also can be the form of acid, and this has proved effective in experiment of the present invention.

By above explanation and example, clearly, the technician of professional domain can and make various improvement and variation aspect the method for steam stimulation raising oil deposil erude petroleum recovery ratio to surface activator composition.All these variations all belong in the present invention spirit essence and the scope, and are included in the invention scope that claims of the present invention limit.

Claims

1, a kind of method that during reservoir gas injection, improves this oil deposil erude petroleum recovery ratio, comprise that known depth well section is regularly injected a kind of anionic surfactant solution or gas and a kind of anionic surfactant solution toward described oil reservoir in a bite well, so that existing under the remaining oil condition, the high osmosis gas passage on described stratum generates foam, reservoir fluid in the described stratum and formed foam and gas contact leaving described injection well section place, the described reservoir fluid of help promotion flows to the producing well section in the oil reservoir, and from described producing well section extraction crude oil; It is characterized in that described anionic surfactant solution comprises that a kind of mean molecule quantity of effective dose is at least 400 alkyl aromatic sulfonate component, wherein at least one alkyl has 15-30 carbon atom, and described alkyl has three secondary carbons or tertiary carbon atom at least.

2, according to the process of claim 1 wherein that described gas is steam, described alkyl aromatic sulfonate is about 0.01% to 5% of a described steam water.

3, according to the method for claim 2, what wherein the gas phase of steam also comprised about 1%-50% can not condensing gas.

4, according to the method for claim 3, wherein said gas comprises nitrogen, methane gas, flue gas, carbon dioxide gas, carbon monoxide gas or air.

5, according to the process of claim 1 wherein that described gas comprises nitrogen, methane gas, flue gas, carbon dioxide gas, carbon monoxide gas or air.

6, according to the process of claim 1 wherein that the aromatic components of described alkyl aromatic sulfonate is a benzene.

7, according to the process of claim 1 wherein that the aromatic components of described alkyl aromatic sulfonate is a toluene.

8, according to the process of claim 1 wherein that the aromatic components of described alkyl aromatic sulfonate is a dimethylbenzene.

9, according to the process of claim 1 wherein that the sulfonate component of described alkyl aromatic sulfonate is the form of water soluble salt, be selected from salts such as comprising sodium, potassium, ammonium.

10, according to the method for claim 9, the water soluble salt of wherein said sulfonate component is a sodium salt.

11, according to the process of claim 1 wherein that the sulfonate component of described alkyl aromatic sulfonate is the form of acid.

12, according to the process of claim 1 wherein that described solution also comprises one or more components that are selected from alhpa olefin sulfonate component, sodium metasilicate component and the sodium chloride component etc.

13,, except that described alkyl, also comprise 0-2 the positive alkyl substituent that 0-3 carbon atom arranged according to the process of claim 1 wherein described alkyl aromatic sulfonate component.

14, according to the method for claim 2, the water of wherein said steam also comprises 0.01% to 5% electrolyte.

15, according to the method for claim 2, wherein said water comprises the anion surfactant of 0.1% to 5% different structure.

16, according to the method for claim 15, wherein said anion surfactant is selected from one or more components in the components such as alhpa olefin sulfonate, alhpa olefin sulfonate dimer and straight chained alkyl aromatic sulphonate.

17, according to the process of claim 1 wherein that injection well and producing well are same wells.

18, according to the method for claim 1, this oil reservoir is drilled with at least and injects well flatly and have a bite producing well at least, and described method comprises: form steam and alkyl aromatic sulfonate foam; Make described steam and alkyl aromatic sulfonate foam enter described stratum, leave described injection well, help is pushed crude oil to producing well, recover the oil at described producing well, it is characterized in that described alkyl aromatic sulfonate has the mean molecule quantity of 400-600, and comprise that at least one has the alkyl of 15-30 carbon atom; Described alkyl have at least three secondary carbons and (or) tertiary carbon atom.

19, according to the method for claim 18, wherein the steam water contains about 0.01% to about 5% alkyl aromatic sulfonate.

20, according to the method for claim 19, wherein quantity be described steam gas phase about 0.1% to about 50% can not condensing gas, inject well together in company with steam.

21, according to the method for claim 20, can not condensing gas be one or more gases of from gases such as nitrogen, methane gas, flue gas, carbon dioxide gas, carbon monoxide gas or air, selecting wherein.

22, according to the method for claim 18, wherein the aromatic components of alkyl aromatic sulfonate is a benzene.

23, according to the method for claim 18, wherein the aromatic components of alkyl aromatic sulfonate is a toluene.

24, according to the method for claim 18, wherein the aromatic components of alkyl aromatic sulfonate is a dimethylbenzene.

25, according to the method for claim 18, the sulfonate component of wherein said alkyl aromatic sulfonate is the form of water soluble salt, is selected from salts such as comprising sodium, potassium, ammonium.

26, according to the method for claim 18, the water soluble salt of wherein said sulfonate component is a sodium salt.

27, according to the method for claim 18, the sulfonate component of wherein said alkyl aromatic sulfonate is sour form.

28, according to the method for claim 18, wherein the sulfonate component of alkyl aromatic sulfonate is the form of water soluble salt, is selected from sodium, potassium and ammonium cation or its mixture.

29, according to the method for claim 18, the aromatic components of its alkyl aromatic sulfonate except that described alkyl, also comprises the positive alkyl substituent of 0-3 carbon atom of 0-2 band.

30, according to the method for claim 18, wherein the water of steam contains the electrolyte of 0.01%-5%.

31, according to the method for claim 18, the water of wherein said steam contains the anion surfactant of 0.1%-5% different structure.

32, according to the method for claim 31, wherein said anion surfactant is alhpa olefin sulfonate, alhpa olefin sulfonate dimer or straight chained alkyl aromatic sulphonate.

33, method according to claim 1, this method comprises from injecting well flatly regularly injects a kind of aqueous solution toward described oil reservoir, so that have at described oil reservoir high osmosis gas passage under the situation of residual oil existence, form foam with described gas, the described aqueous solution comprises a kind of anion surfactant, it has a kind of alkyl aromatic sulfonate component, wherein alkyl has 15-30 carbon atom, also has a kind of alhpa olefin sulfonate dimer component, the ratio of described two components be 1: 10 to 10: 1(weight), and the concentration of described two components in solution is 0.1% to 10%(weight).

34, method according to claim 1, this method comprises from injecting well flatly regularly injects a kind of aqueous solution and gas toward described oil reservoir, so that have at described oil reservoir high osmosis gas passage under the situation of residual oil existence, form foam with described gas, the described aqueous solution comprises a kind of anion surfactant, it has a kind of alkyl aromatic sulfonate component, wherein alkyl has 15-30 carbon atom, also has a kind of alhpa olefin sulfonate dimer component, the ratio of described two components be 1: 10 to 10: 1(weight), and the concentration of described two components in solution is 0.1% to 10%(weight).