CN105008660A

CN105008660A - Method and system of optimized steam-assisted gravity drainage with oxygen ("SAGDOX") for oil recovery

Info

Publication number: CN105008660A
Application number: CN201380070818.4A
Authority: CN
Inventors: R·K·克尔
Original assignee: Nexen Energy ULC
Current assignee: CNOOC Petroleum North America ULC
Priority date: 2012-11-19
Filing date: 2013-11-19
Publication date: 2015-10-28
Also published as: US20140076555A1; CA2833498A1; WO2014075175A1

Abstract

A steam assisted gravity drainage with injected oxygen (SAGDOX) process to recover hydrocarbons in a hydrocarbon reservoir including: (a) starting the SAGDOX process at a first oxygen to steam ratio; (b) measuring a produced water to oil ratio (v/v) PWOR associated with the first oxygen to steam ratio; (c) adjusting the oxygen to steam ratio to obtain a predetermined PWOR; and (d) continuing steps (a) to (c) until a target PWOR is obtained improving the hydrocarbon recovery rate.

Description

For SAGD (" the SAGDOXO ") method and system of the use oxygen of optimization of recovering the oil

Background technology

SAGD (" SAGD ") uses in saturated vapour Injection Level well 2, business-like hot intensified oil reduction (" EOR ") technique, wherein use latent heat to carry out heated asphalt and reduce the viscosity of pitch, it is made to let out in parallel, the paired parallel horizontal wells (i.e. recovery well 4) of below by gravity, completion (Fig. 1) near bottom reservoir.Steam regulation charge velocity is to reach goal pressure.Regulates liquid produces speed to reach target temperature, in its several years lower than saturated-steam temperature, makes live steam not penetrate recovery well.

Since this technique starts (Butler in early days in the 1980's, R.M., " ThermalRecovery of Oil & Bitumen ", Prentice-Hall, 1991), SAGD has become the main in-situ process in order to pitch of gathering in the Pitch deposits from Alberta province (Alberta).The SAGD bituminous production economized at Alberta is at present about 300,000 barrels/day (bbl/d) (Oilsands Review, (2010)), and installed capacity is about 475,000 barrels/day (ibid).SAGD is hot EOR technique advanced in the world now.

Fig. 1 (prior art) demonstrates " traditional " SAGD geometry, it is used in paired, parallel, horizontal well 2,4 that same perpendicular is holed, upper Injection Well 2 and lower recovery well 4, spacing between described two wells 2,4 is 5 meters, each well is about 800 meters, and (or recovery well 4) above the substrate of (level) reservoir 1 to 2 meters of going into the well.SAGD technique is started by cyclic steam in two wells.After setting up UNICOM, well is used to inject steam 6 and go into the well extraction hot water and heated bitumen 8.Liquid extraction is realized by natural elevate a turnable ladder, gaslift or submersible pump.

After being transformed into normal SAGD operation, vaporium 10 is formed around Injection Well 2 and recovery well 4, and wherein void space is occupied by steam 6.It is how ripe that Fig. 2 (prior art) shows SAGD.Steam 6, in the border condensation of room, discharges latent heat (condensation heat) and heated asphalt, connate water and reservoir matrix.Let out in lower recovery well 4 by gravity by the pitch that heats and water 8.Along with releasing of pitch, vaporium 10 upward and outward increases.The vaporium 10 at initial stage makes pitch from side, precipitous room with from room top layer draining.When room 10 increases touching reservoir top, top layer draining stops, and asphalt production rate reaches peak value and angle of sides proceeds along with side direction increases and declines.Heat waste increases with top layer contact and long-pending increase of steam chamber surface and increase that (steam increases (Fig. 8) with oily ratio (" SOR ").Draining speed reduces with side wall angle (θ) and slows down.Finally, limit is economically reached and the draining angle of end of lifetime is little (10-20 °), as shown in Fig. 2 (prior art).

The fluid of extraction, close to saturated-steam temperature, therefore only has the technique that the latent heat of steam contributes in reservoir.But, some sensible heats can be caught from surface heat exchanger (part larger higher temperature), therefore for the pressure (" P ") of most of SAGD project and temperature (" T ") scope, the useful rule of thumb of steam net heat contribution is 1000BTU/ pound, shown in as good in Fig. 3 (prior art) institute.

The operating characteristics of SAGD can be characterized by the measurement of following parameter: saturated vapour P and T (Fig. 2) in vaporium; Asphalt production rate; SOR, usually at well head (" wh "); Cross cold---the temperature difference between saturated vapour and extraction fluid; With water circulation ratio (" WRR ")---recovered water and the ratio injecting steam.

In SAGD activities, SAGD operator needs to carry out twice selection---cross the operating pressure P in cold target temperature difference and reservoir.It is in order to ensure not having live steam to penetrate into recovery well that the typical case of about 10 to 30 DEG C crosses cold target temperature difference.Operation pressure and temperature correlation connection, as the best in Figure 14 (prior art) illustrates, and mainly relate to asphalt production rate and process efficiency.Asphalt viscosity is the majorant of temperature, and as shown in Fig. 5 (prior art) the best, asphalt viscosity raises with temperature and reduces.According to Gravdrain equation, as shown in Fig. 6 (prior art), SAGD productivity ratio is proportional to the square root of reciprocal viscosity, (Butler (1991)).On the contrary, if P and T increases, then the latent heat of steam controls to decline (Fig. 3) rapidly and more energy is used to heating Rock Matrix and is lost to covering layer or other non-producing region.Therefore, the P of increase adds asphalt production rate, but harm process efficiency (improve SOR).Because economic benefit can be dominated by asphalt production rate, thus SAGD operator usually select using operating pressure higher than natural, hydrostatic reservoir pressure as target.

Although becoming main hot EOR technique, SAGD has some restriction and impaired parts.Good SAGD project comprises:

Horizontal well is completed effectively to collect and to produce hot draining fluid near bottom oil-producing area.

In sand face, (" sf ") injects high-quality steam.

It is effectively with easily that technique starts.

Vaporium grows steadily and is received.

Reservoir matrix quality good (porosity (" Φ ") >.2, initial oil saturation (" S _i0") >.6, kinematic viscosity (" k _v") >2 ties up (" 2D ")).

Clean oil-producing formation is enough (>15 rice is thick).

Suitable design and control are to prevent steam from penetrating, prevent Injection Well overflow, stimulate vaporium to rise to mining area and suppress water to flow into vaporium simultaneously.

Obvious reservoir is not had to roll over block material (such as poor district) or barrier (such as shale).

If these necessary conditions do not realize or stand other restrictions, so SAGD can be impaired, as follows:

(1) preferred main exploitation mechanism is gravity drainage and lower recovery well is level.If reservoir high inclination, then horizon mining well can be detained (strand) significant resource.

(2) SAGD steam-purge zone has the remarkable residual bitumen content of not gathering, particularly for compared with the pitch of heavy and low-pressure steam, as shown best in figure 26.Fig. 4 (prior art) depicts the mark of the residual bitumen in the hole of pitch and mink cell focus.Such as when 20% residual bitumen (hole saturation ratio) and 70% initial saturation, recovery ratio only has 71%, does not comprise below recovery well or delay pitch in the tapered region of gathering between well pattern.

(3) in order to hold SAGD vaporium, the oil in reservoir must be geo-stationary.SAGD can not work to heavy (or lightweight) oil under reservoir conditions with mobility.Pitch is selected objective target.

(4) saturated vapour can not evaporate connate water.According to definition, the thermal energy in saturated vapour does not have sufficiently high quality (temperature) with evaporation water.Field experience also demonstrates for product bitumen layer, and the connate water of heating does not have enough mobility with extraction in SAGD.Recovered water is similar with SOR with the ratio (PWOR) of oil.This makes SAGD be difficult to break or utilize poor area resource.

(5) existence in active pool---the top layer water in oil-producing area or poor district of distribution---can cause SAGD operating difficulties (Nexen Inc., " Second Quarter Results ", on August 4th, 2011) (Vanderklippe, N., " Long Lake Project Hits StickyPatch ", CTV, 2011), or finally can cause project failure.Analog study is reached a conclusion, the standoff distance increasing recovery well can optimize the performance of the SAGD with active bottom water, comprise good Stress control to minimize water influx (Akram, F., " Reservoir SimulationOptimizes SAGD; American Oil and Gas Reporter (AOGR), in September, 2011).

(6) (always) pressure target can not be improved to improve SAGD productivity ratio and SAGD economy.If reservoir is " leakage ", so along with raising pressure exceedes natural hydrostatic pressure, SAGD technique can lose water or steam to the region outside SAGD vaporium.If fluid loss, then water circulation ratio (" WRR ") reduces and technological requirement significant water compensation volume.If steam also loses, then process efficiency declines and SOR rising.Finally, if pressure is too high, and if if reservoir shallow high pressure retention time is long, then can there is steam, sand and penetration by water surface (Roche, P., " Beyond Steam ", New Tech.Mag., in September, 2011).

(7) steam cost is considerable.For the facility comprising Capital expenditure and some profits, the cost of the high quality steam in sand face is about $ 10 to $ 15/ mmbtu (MMBTU).High steam cost can reflect resource quality limit and ultimate recovery.

(8) use of water is remarkable.Suppose SOR=3, the yield of WRR=1 and produced water treatment (that is, recycling) is 90%, and typical SAGD water is 0.3 barrel of compensation water/bucket extraction pitch.

(9) SAGD process efficiency " bad " and CO ₂discharge value remarkable.If SAGD efficiency is defined as [(pitch energy)-(surface energy of use)]/(pitch energy) and pitch energy=6MMBTU/ bucket; Energy=1MMBTU/ bucket the pitch (SOR ~ 3) used in sand face; Steam produces in combustion type boiler with the efficiency of 85%; Be assigned to well head and be delivered to each heat waste of own 10% in sand face from well head; Available steam energy is 1000BTU/ pound (Fig. 3) and boiler oil is the methane of 1000BTU/SCF; So SAGD process efficiency=75.5% and CO ₂discharge value=0.077 ton of/barrel of pitch.

(10) due to heat waste, the cost of the pressure loss and isolation distributing steam pipeline, actual steam is distributed distance and is restricted to about 10 to 15 kilometers of (6-9 mile) (Finan, A., " Integration of Nuclear Power ... " MIT paper, in June, 2007 (EnergyAlberta Corp., " Nuclear Energy ... " Canadian Heavy Oil Associationpres. (CHOA), on November 2nd, 2006).

Finally, there is the long and/or well diameter of restriction well and the natural waterpower limit of the pressure target of SAGD operation can be had precedence over.What Fig. 9 (prior art) demonstrates and can occur to occur with what.In SAGD, form vapor/liquid interface 12.For the good SAGD operation with cold control, vapor/liquid interface 12 is between Injection Well 2 and recovery well 4.Because the pressure drop in the recovery well 4 that the friction loss of fluid flowing causes, vapor/liquid interface 12 tilts.In steam gas room pressure reduction very little/there is no pressure reduction.If liquid extraction speed too high (if or recovery well too little), so interface 12 can be tilt, and the toe of steam injection well 14 (toe) is submerged and/or being exposed to steam penetrating (Fig. 9) with (heel) of recovery well 16.(for 5 meters of spacing, be about 8psi (50kPa)) when the pressure drop in recovery well 4 exceedes the hydrostatic head between steam injection well 2 and liquid recovery well 4, this restriction can occur.

Use the SAGD (" SAGDOX ") of oxygen to be the hot EOR technique improved, wherein steam and oxygen are all injected in bitumen reservoir.As Figure 10 the best illustrates, SAGDOX use the horizon mining well 4 that is similar to SAGD and by various vertically or horizontal well structure add oxygen and inject 26, to inject steam 6 and oxygen 26 and to remove non-condensable burning gases 22 (being namely vented) (Figure 10 (a), 11 (a), 11 (b) and 12).Figure 11 (a) depicts single recovery well, and its medium pitch and water 8 are gathered by perforation 19, and non-condensable gas 22 is discharged by independent ring.Oxygen 26 and steam 6 inject oil-producing formation 5 by independent Vertical Well.Figure 11 (b) depicts single recovery well, and wherein oxygen 26 and steam 6 are injected into oil-producing formation 5, and incoagulable gas 22 is discharged by independent ring, and pitch and water 8 are gathered in same well, and all is all isolated from each other.Figure 12 depicts three kinds of preferred geometries.SAGDOX technique can be considered to mixing SAGD and situ combustion (" ISC ") technique.Use the burning original position of oxygen to produce heat, it is more cheap and more efficient than steam.Steam promotion kinetics of combustion, improves and conducts heat and facilitate lateral growth.Steam regulation and oxygen charge velocity and exhaust removing speed are to reach goal pressure.By the mistake similar with SAGD cold target temperature control production speed.Regulate oxygen/steam ratio in the scope of 0.05-1.00 (v/v), or in other words steam and oxygen ratio are 19-1.

The oxygen that the old model of SAGDOX provides and steam ratio are only in the scope of 0.05-1.00.Need expansion oxygen and steam ratio more than 0.05-1.00 and determine operating condition best in SAGDOX.

Summary of the invention

According to an aspect, provide a kind of method improving SAGDOX, described method comprises use recovered water with oily ratio (v/v) (" PWOR ") to determine best SAGDOX technological parameter.

According on the other hand, provide PWOR and controlling the purposes in hot EOR, preferably optimize hot EOR, more preferably optimize the SAGDOX in hydrocarbon is gathered.

According to another aspect, the use providing improvement injects SAGD (" the SAGDOX ") method of oxygen with recovery of hydrocarbons, and described method comprises:

A () starts described SAGDOX technique under the first oxygen and steam ratio;

B () measures the PWOR relevant with steam ratio to described first oxygen;

C () regulates described oxygen and steam ratio to obtain the 2nd PWOR;

D () measures the hydrocarbon recovery ratio relevant to described 2nd PWOR; And

E () repeats step (c) with (d) until reach the PWOR target improving described hydrocarbon recovery ratio.

In one embodiment, described improvement comprises expansion oxygen and the steam ratio scope more than 0.05-1.00 (v/v), and preferred steam and oxygen ratio are about 19 be still greater than zero to close to zero.In one preferred embodiment, in described oxygen and vapour mixture, the percentage of oxygen is greater than 50% (v/v).

Preferably, improving the described PWOR target that described hydrocarbon gathers is about 0.5 to 2.0, preferably 1.0.More preferably, described PWOR target can be maximum value, and wherein the amount of described oxygen is in the process greater than 0% close to zero.

In another embodiment, described improvement comprise use PWOR go to choose best oxygen and steam ratio.In another embodiment, described improvement comprises adjustment pressure and crosses cold target to optimize SAGDOX.Preferably, regulate oxygen and steam ratio to reach target P WOR (recovered water and oil ratio rate).In another embodiment, PWOR target is selected to optimize oxygen and steam ratio in SAGDOX technique.In one embodiment, the oxygen of described injection is oxygen-containing gas.

According to an aspect, provide and use substantially horizontal recovery well, the method for liquid hydrocarbon of gathering from the hydrocarbon reservoir with top and bottom, wherein:

(1) described substantially horizontal recovery well production of water and liquid hydrocarbon from described reservoir; Preferably, described substantially horizontal recovery well completion in 2 meters bottom reservoir;

(2) oxygen is injected in hydrocarbon reservoir, preferably above described substantially horizontal recovery well, preferably apart from described substantially horizontal recovery well 50 meters; Preferably, described oxygen is injected by least one oxygen Injection Well or site; At least one oxygen Injection Well described or site have at least one reservoir contact zone to contact described reservoir, and described district preferred length is less than 50 meters;

(3) by steam injection hydrocarbon reservoir, preferably above described substantially horizontal recovery well, preferably apart from described substantially horizontal recovery well 20 meters; Wherein

(4) oxygen produces heat by burning original position, steam is by conducting and producing heat by condensation original position, liquid hydrocarbon is caused to be heated, reduce its viscosity to make it pass at least one reservoir contact zone described to release horizon mining well by gravity, described liquid hydrocarbon preferably transmits (more preferably pumping) to earth's surface;

(5) control to inject the oxygen of described hydrocarbon reservoir to steam to obtain target recovered water and oil ratio rate (v/v) (" PWOR "); Preferably, the described oxygen of injection and steam have 19 to being greater than the steam of zero and the ratio of oxygen;

(6) be removed from reservoir, the preferably described substantially horizontal recovery well of disengaging by least one exhaust site by the non-condensable gas of burning generation and the inert gas (" exhaust ") in oxygen-containing gas, be more preferably removed to about 75 meters of apart from described substantially horizontal recovery well about 5; And

(7) more preferably, apart from least one exhaust removing, at least 100 meters, site described at least one exhaust removing preset distance place, site described, preferred distance, described steam and oxygen is injected.

Preferably, but PWOR target, between 0.5 and greater value, makes the amount of described oxygen in the process close to zero is greater than zero, more preferably 0.5 and about between 2.0.

Preferably, by changing PWOR, until make cost, preferably operation cost/bucket pitch minimize, and determine PWOR target at the scene.

Optionally, according to a kind of embodiment, do not need to remove the inert composition in non-condensable burning gases or oxygen-containing gas.

Preferably, by steam injection apart from described horizontal well 10 meters, be more preferably used in parallel, the horizontal well in the perpendicular identical with horizon mining well, and at described aboveground side 3 to 8 meters of.

In another embodiment, the Vertical Well substantially using at least one single, preferably multiple Vertical Well are substantially by steam injection reservoir.

In another embodiment, oxygen, preferably oxygen-containing gas are injected reservoir by the Vertical Well substantially using at least one single, preferably multiple Vertical Well substantially.

In another embodiment, exhaust removes by the Vertical Well substantially using at least one single, preferably multiple Vertical Well substantially from reservoir.

In another embodiment, described steam and oxygen jointly mix on earth's surface and the Vertical Well substantially using at least one single, preferably multiple Vertical Well are substantially injected in reservoir.

Having in a kind of embodiment, described steam and oxygen use packer to isolate at least one single Vertical Well substantially, preferably multiple Vertical Well substantially, and inject reservoir respectively.

According to another kind of embodiment, described steam and oxygen use concentric tube and packer isolation in described well, and the steam in preferred center pipe is surrounded by the oxygen in adjacent ring, and preferred described oxygen injects described reservoir with the height higher than described steam injection height.

According to another embodiment, described method uses single Vertical Well substantially to inject steam and oxygen, and wherein said single Vertical Well is substantially completion within 50 meters, the toe apart from described horizon mining well.

According to another kind of embodiment, described exhaust uses a well, preferably Vertical Well removing substantially.In another embodiment, described exhaust uses the removing of multiple Vertical Well.

Preferably, described exhaust removing with the eseparation ring section in the ascent stage by horizontal well.

In another embodiment, oxygen injects described reservoir by the toe section of the separation of horizontal well.

In another embodiment, steam injects described reservoir by the toe section of the separation of horizontal well.

In another embodiment, described steam and oxygen mix on earth's surface, and inject described reservoir by the toe section of the separation of horizontal well.

In another embodiment, described oxygen is isolated with steam and injects described reservoir by the toe section be separated of horizontal well simultaneously.

In another embodiment, described isolation uses concentric tube and packer to complete, and steam is in central tube, and it is surrounded by the oxygen in adjacent ring.

In another embodiment, described exhaust removes following in the eseparation ring in the ascent stage of horizontal well.

In another embodiment, the toe up-hole of described horizontal well completion, make minimum injection aperture (for steam or oxygen-containing gas or the two) in height higher than the horizontal plane of the horizontal segment of recovery well, preferably in height high than the horizontal plane of the horizontal segment of recovery well more than 2 meters.

In another embodiment, described horizontal well is arranged essentially parallel to bottom described reservoir with the updip direction in inclination reservoir and holes, and makes minimum injection aperture in height higher than the highest liquid exploitation aperture, more preferably in height high more than 2 meters than the highest liquid exploitation aperture.

In another embodiment, oxygen-containing gas is oxygen, and oxygen content is 95-99.99 (v/v) %.

In another embodiment, oxygen-containing gas is air, preferred oxygen-enriched air, and oxygen content is 21-95 (v/v) %.

In another embodiment, described method also comprises the extension tube of toe used near recovery well, guarantees that minimum pressure in recovery well is close to described toe.

When liquid hydrocarbon is pitch, preferred API density is less than 10, and original position viscosity is greater than 100,000cp.When liquid hydrocarbon is mink cell focus, preferred API density is 10 to 20, and original position viscosity is greater than 1,000cp.

In one embodiment, horizon mining well spacing is less than 2.0 meters from the bottom of reservoir at its closest approach place.

Preferably, by changing PWOR until asphalt production rate maximizes, PWOR target is determined.

Accompanying drawing explanation

Fig. 1 describes traditional SAGD geometry.

Fig. 2 depicts SAGD life cycle.

Fig. 3 depicts saturated vapour character.

Fig. 4 depicts the residual bitumen in steam blowing district.

Fig. 5 depicts the viscosity of pitch and the relation of temperature.

Fig. 6 depicts the Gravdrain equation for SAGD asphalt production rate.

Fig. 7 depicts SAGDOX and changes ISC into.

Fig. 8 depicts the SOR of steam EOR under various initial oily saturated level.

Fig. 9 depicts the SAGD waterpower limit during good and poor operating condition.

Figure 10 depicts the SAGDOX geometry of preferred embodiment, and exhaust site separates with Injection Well and recovery well.

Figure 10 a depicts the SAGDOX geometry of preferred embodiment, and exhaust site is close to recovery well.

Figure 11 a depict the toe of preferred embodiment-to-with SAGDOX geometry, oxygen and steam inject at the toe place close to recovery well.

Figure 11 b depicts individual well SAGDOX preferred embodiment, has the toe geometry of rising.

Figure 12 depicts three preferred embodiments of SAGDOX geometry.

Figure 13 depicts the relation of the H/C atom ratio of combustion heat release HHV and fuel.

Figure 14 depicts the pressure of saturated vapour and the relation of temperature.

Figure 15 depicts the relation that SAGDOX mechanism is gathered with hydrocarbon.

Figure 15 (a) depicts the lateral view of the well pattern of gathering of THSAGDOX.

Figure 16 depicts the relation of minimum air flow rate for burning and crude oil gravity.

Figure 17 depicts steam and oxygen combustion tube test I.

Figure 18 depicts steam and oxygen combustion tube test I I.

Figure 19 depicts SAGDOX combustion chemistry.

Figure 20 depicts the relation of SAGDOX combustion components PWOR and initial bitumen saturation ratio.

Figure 21 depicts the relation (when energy and oil ratio rate (" ETOR ")=1.0) of PWOR and initial bitumen saturation ratio.

Figure 22 depicts the relation of PWOR and ETOR, supposes S _iobe 0.80.

Figure 23 depicts the combustion components PWOR when SAGDOX end of lifetime.

Figure 24 depicts gradual change oxygen strategy when ETOR rising or SAGDOX maturation.

Figure 25 depicts WRR and the relation of initial bitumen saturation ratio under various oxygen concentration.

Figure 26 depicts the relation of % oil/pitch recovery ratio in steam blowing district and initial oil/pitch saturation ratio.

Detailed description of the invention

The object of SAGDOX reduces reservoir energy to inject cost, keeps good efficiency and productivity ratio simultaneously.Oxygen combustion produces in-situ heat (Figure 13, Butler (1991)) with the speed of about 480BTU/SCF oxygen (fuel independent of burning).Ignition temperature is independent of pressure and they are higher than saturated-steam temperature (Fig. 3,14).The higher temperature carrying out spontaneous combustion evaporates connate water and some steam that reflux.Steam sends EOR energy from the latent heat discharged by condensation with net value, and the surface heat comprising about 1000BTU/ pound reclaims (Fig. 3).Table 1 illustrates the thermal property of steam+oxygen mixture.Per unit is delivered to the heat of reservoir, oxygen volume is less than 1/10th of steam, and the cost of oxygen (comprising capital cost) is that the half of steam cost is to 1/3rd.

More complicated than SAGD of mechanism of gathering of SAGDOX.As shown in Figure 15 the best, within burning purging region 170 is accommodated in steam-purge zone 170.Residual bitumen in steam-purge zone 120 by hot combustion gas heating, fractionation and pyrolysis to be provided as the coke of burning natural fuel.The gas compartment formed contains steam burning gases, the connate water of evaporation and other gas.Large gas compartment can be subdivided into burning-purge zone 100, burning proparea 110, pyrolysis zone 120, heated bitumen bank 130, superheated steam zone 140 and saturated vapour district 150.Condensed steam is released from the top layer of saturated vapour district 150 and gas compartment and wall.Heated bitumen releases from the heated bitumen district at the edge in the top layer of described room and wall and burning proparea 110.Condensed water and heated bitumen 8 are collected by lower horizontal well 4 and are transported (or pumping) to earth's surface (Figure 10).Figure 15 (a) describe burning purge zone how to grow in SAGDOX activities.

Burning incoagulable gas is collected and passes through exhaust shaft or remove in the exhaust site be separated (being respectively Figure 10,10 (a), 11 (a) and 11 (b)).In one embodiment, by the generation of exhaust can independent of liquid exploitation rate partly Controlling Technology pressure.The generation of exhaust also can be used for the direction and the speed that affect gas compartment growth.

some SAGDOX character comprise:

(1) oxygen (instead of air) is used to inject as oxidant

If consider that process exhaust is to remove sulphur component and the cost of volatile hydrocarbon of gathering, then for the energy that per unit is delivered to reservoir, even if at low pressures, the complete cost of oxygen is also less than compressed-air actuated cost.

Send for identical energy, oxygen occupies the volume relative to air about 1/5th.Well conduit/Guan Geng little, and oxygen can be transported to from the farther distance in central plant position.

The situ combustion of oxygen is used mainly to produce not with the incoagulability CO of nitrogen dilution ₂.CO ₂pitch can be dissolved in boost productivity.Dissolve by using oxygen and maximize.

When using oxygen, if exhaust main CO ₂and (sequester) can be buried in independent position or independent layer position (horizon).

There is minimum oxygen flow to maintain high-temperature oxydation (" HTO ") burning (Figure 16), Figure 16 shows air rate.Oxygen speed is about 1/5 air rate.When combustion zone thickness increases, minimum ISC air rate reduces.

More easily reach/maintain this flow using oxygen

(2) oxygen is kept to inject at concentrated position

Due to the minimum O from situ combustion ₂traffic constraints (Figure 16), thus oxygen Injection Well (or segregation section) contact with reservoir should more than 50 meters.

(3) oxygen separation and steam injection thing as far as possible

Condensed steam (hot water) is very strong to the corrosivity of carbon steel with oxygen.

In order to minimum corrosion, or: oxygen and steam are injected (Figure 10,11 (a)) or (ii) by (i) respectively makes the steam of common mixing and oxygen limitedly be exposed to the pipeline section that can be corrosion resisting alloy, or the integrality being exposed to the common steam of mixing and the section of oxygen is not crucial (Figure 11 (b)) to described technique, or whole injection band is made up of corrosion resisting alloy.

(4) exhaust shaft (or position) is near reservoir top, and away from oxygen injection phase.

Due to movement and the condensation of steam, incoagulable gas concentrates on the near top of gas compartment.

Exhaust shaft away from oxygen Injection Well with allow burning and heat trnasfer time/space.

(5) exhaust should not produce with significant oxygen content

Explode for alleviating and cultivate good oxygen utilization, any have be greater than 5% (v/v) oxygen content exhaust produce should by closing well.

(6) steam reaching in reservoir/minimally measure

In SAGDOX, add/inject steam with oxygen, because steam assisted burning.Steam preheating reservoir, makes the igniting of HTO can be spontaneous.Steam adds OH to combustion zone ^-and H ⁺free radical is to improve and stabilizing burning (Figure 17 and Figure 18) (personal communication).This have also been obtained smokeless combustion operation confirmation, wherein add steam with improve burn and reduce smog (Stone, D. etc., " Flares ", chapter 7, www.gasflare.orgin June, 2012, EnvironmentalProtection Agency (" EPA ") " Industrial Flares ", EPA.gov, in June, 2012) (Shore, D. " Making the Flare Safe ", J.Loss Prev.Proc.Ind., 9,363,1996).This technique for vaporising fuel also adds steam to minimize the generation (Berkowitz, N., " fossil Hydrocarbons ", Academic Press, 1997) of cigarette ash to partial combustion device.

Steam also condensation produce and cover horizontal recovery well and this well and gas or steam are invaded the water of isolating.

Water is added recovery well may improve liquidity energy---water/asphalt emulsion---compared with independent pitch by steam condensate.

Steam is also heat transfer agent excellent in reservoir.If compare hot combustion gas (mainly CO ₂) with steam time, the heat transfer advantages of steam is obvious.Such as, if the edge of hot gas room is about 200 DEG C, then burning gases are cooled to the available heat of 200 DEG C for about 16BTU/SCF from 500 DEG C.The saturated vapour of same volume contains the latent heat of 39BTU/SCF, and the twice exceeding combustion gas energy content is many.In addition, when hot combustion gas cools, they become effective slider, hinder and conduct heat further.When steam is condensed to send latent heat, it create of short duration low pressure, described low pressure is drawn into more steam---and can compared with heat pump.Kinetics is also conducive to steam/water.Be about 6.8 (mW/cmK) water coefficient of thermal conductivity compared with---add 20 times, the thermal conductivity of burning gases is about 0.31 (mW/cmK).Therefore, the subject under discussion that the side direction that burning (without steam) has slow heat transfer and difference increases.These subjects under discussion can be relaxed by steam injection.

Due to the amount of steam in reservoir cannot be measured, so SAGDOX arranges steam minimum value by the oxygen of 50% (v/v) in maximum oxygen/steam (v/v) ratio of 1.0 or steam and oxygen mixture.

(7) reach (or exceeding) minimum oxygen to inject

During oxygen lower than about 5% (v/v) in steam and oxygen mixture, burning purge zone is little and oxygen cost advantage is minimum.In this level, only have an appointment 1/3rd Implantation Energy be due to burning.

(8) maximum oxygen injects

In the constraint of above-mentioned (6) and (7), because per unit energy oxygen is expensive not as steam, institute is maximization oxygen/steam ratio for the selection of the least cost of exploitation pitch.

(9) preferred SAGDOX geometry is used

According to individual applications, reservoir matrix character, properties of fluid in bearing stratum, the degree of depth, clean oil-producing area, pressure and Location factor, there are three kinds of preferred geometries (Figure 12) for SAGDOX.

Option B-toe-to-be best suited for small property oil area resource with SAGDOX (" THSAGDOX ") and C-individual well SAGDOX (" SWSAGDOX "), only require a horizontal well.Compared with SAGD, THSAGDOX and SWSAGDOX has the well number of minimizing and lower drilling cost.And interior pipe and packer should can be used for multiple application.

(10) by controlling SAGDOX/operate as follows:

The cold control of mistake for fluid exploitation rate, wherein makes comparisons extraction fluid temperature (F.T.) and saturated-steam temperature under reservoir pressure.It supposes the gas mainly steam be close to above liquid/gas interface.

Adjustment oxygen/steam ratio (v/v) to meet target rate, its according to 0.05 to 1.00 range limits

Regulate exhaust to remove speed and make gas mainly incoagulable gas, oxygen content is less than 5.0% (v/v), and reach/keep pressure target.

With above-mentioned (iii) steam regulation and oxygen charge velocity (according to above-mentioned (ii)) in the lump, reaching/keep pressure target.

the SAGDOX technique improved

For original SAGDOX, a kind of control of suggestion is the target vapor/oxygen mixture chosen for injecting.But except the scope (or oxygen with steam ratio be 0.05 to 1.00) of 5-50% (v/v) oxygen in suggestion mixture, what there is not is best composition or how to select the best criterion formed.SAGDOXO (SAGDOX – optimizes) method overcomes this shortcoming.For choosing target composition existence two consideration:

(1) oxygen is more cheap and more effective than steam.Therefore, separately based on these standards, oxygen level should be maximized.

(2) steam is very useful in storage collecting method.Except providing latent heat to pitch, its preheated burning district, it is heat transmission medium more better than hot combustion gas, and from the water of steam when mix with the pitch of exploitation, produce emulsion (or mixture), it is easier to generation than pitch itself.In reservoir, there is best vapor level, which give the great majority of these benefits, and allow to increase oxygen level as far as possible practically.

The key of SAGDOXO method finds best vapor level and/or to determine the measured value relevant to vapor quality, permissions is optimized vapor level by Field adjustment by it, keeps described other SAGDOX operation control herein simultaneously.Provide the method optimizing vapor level in SAGDOX, described method comprises selects PWOR target, preferably between 0.5 and greater value, makes oxygen be on close level zero but keep being greater than zero, and more preferably between 0.5 and 2.0, most preferably from about 1.0, it minimizes pitch cost.

In one embodiment, select described PWOR, it maximizes asphalt production rate.

PWOR (fluid of exploitation, water and oil ratio rate) is also with the oxygen of the best and the measuring of steam ratio of electing.Not very useful for SAGD, PWOR, because it is usually close to SOR, and usually there is not the reservoir water source that can affect PWOR and play the property measurements of SAGD method.In SAGD, based on field experience, do not exploit connate water.For SAGDOX, the similar SAGD of behavior of steam component.But combustion components gasifies and produces connate water, makes PWOR>SOR.In stable state, be directly the measuring of steam of the steam that injects of every unit pitch exploitation and extraction for SAGDOX, PWOR.

According to an aspect, provide the SAGDOX method (SAGDOXO) of optimization, it comprises 3 parts below:

(1) determine to measure, preferred PWOR, it can be used as directly being associated with the steam/pitch ratio in reservoir,

(2) in new reservoir, for the PWOR target of SAGDOX operation, it is 0.5 and make oxygen be on close level 0 but between the maximum value keeping being greater than 0, more preferably between 0.5 and 2.0, and most preferably 1.0,

(3) PWOR best for particular reservoir and the method for oxygen/vapour mixture is found, by changing described PWOR target (and oxygen/vapour mixture) to minimize pitch cost or maximize asphalt production rate under rational productivity ratio; And

(4) 19 to close to zero but be greater than zero steam and oxygen ratio.

Embodiment

When analyzing PWOR target implication and the mechanism of SAGDOXO method, carry out supposition below:

(1) the steam EOR that SAGDOX is divided into the similar SAGD of two parts Fang Fa – operates, and it is by steam-condensation transmission heat and release heated bitumen by gravity; And burning EOR by the oxidation of residual bitumen component directly and indirectly heated asphalt.

(2) steam EOR supposes as follows:

Steam energy transmits the clean steam of about 1000BTU/lb (Fig. 3).

The all steam injected go out as hydromining.

In SAGDOX, steam blowing district 170 is (Figure 15) before combustion zone, and the residual bitumen in described district is provided for the fuel precursor burnt.

All connate waters in (saturated) steam blowing district remain in reservoir, consistent with SAGD field experience.

(3) burning EOR part, assuming that as follows:

Burning capacity transmits (Figure 13) with 480BTU/SCF oxygen.

The fuel of burning is coke, and simplified style is CH _.5(Figure 13), its fractionation by the residual bitumen in steam blowing district 170 (Figure 15) and pyrolysis and prepare.

Assuming that HTO completely.Figure 19 provides SAGDOX combustion chemistry.

It is all that as the chemical product of burning, the water of extraction is exploited.

Residual bitumen in burning-purge zone and connate water are zero (Figure 15).Described district is occupied by gas.

With to exploit and all connate waters that the pitch consumed for burning is combined are exploited.

(4) in order to carry out PWOR evaluation, SAGDOX is considered to burning and the linear combination of steam EOR, has supposition below:

Pitch through each partial mining is pro rata distributed by the transmission of energy.

The energy transmitted is at sand face (sf) place.

For steam, between well head (wh) and sand face, there is 10% thermal loss.Due to this heat waste, the steam of condensation releases recovery well and adds recovered water volume.

Initial gas saturation ratio is not had at oil-producing formation.

As the result of said method model, result and impact that said method focuses on PWOR can be assessed as follows:

Be 0.6 to 1.0 carry out PWOR assessment for pitch saturation ratio; In steam+oxygen mixture, oxygen percentage is for being greater than 0 to being less than 100 (v/v) % (preferable range is 5-50%); And ETOR (MMBTU/bbl pitch (" bblB ")) is 1.0 to 2.0 (being equivalent to SOR is 3 to 6), operates for maturation.

The PWOR of 1.0 or larger can cause the operation of well (SAGDOXO), has maximum oxygen content and good heat trnasfer and other benefit (namely for the preferred value of target P WOR) due to steam.But due to geology or fluid properties change, each reservoir (or well pattern of gathering) can be different.SAGDOXO operator can start with PWOR=1 and regulate PWOR to consider concrete reservoir conditions.The operation history of close or similar reservoir also can be used to regulate target.

There are 2 kinds of modes to use field results " optimization " PWOR target.First, PWOR can be used to minimize pitch cost, keep " reasonably " asphalt production rate simultaneously.Secondly, PWOR can be regulated to maximize asphalt production rate.

Based on above-mentioned supposition, for the combustion parts of SAGDOX, Figure 20 demonstrates PWOR performance and depends on ETOR hardly.This is because relative to the connate water be combined with extraction pitch, the water produced as combustion product and the connate water be combined with the pitch of burning are little.

Figure 20 also demonstrates for pitch EOR, the option why dry ISC has not been.If the threshold value of good heat transmission (with other steam benefit) is PWOR=1.0, so dry ISC can not work (i.e. productivity ratio) preferably, unless initial bitumen saturation ratio≤0.5, not rely on ETOR.

Consider that typical pitch saturation ratio is the bitumen reservoir of 0.8, the ETOR=1.0 of our ripe SAGDOXO method operation (is equivalent to SOR ~ 3, for SAGD), and PWOR target is 1.0 (namely extraction fluid is 50% water and 50% pitch).Figure 21 shows SAGDOXO method should with containing 25% (v/v) oxygen of having an appointment, or equivalently, oxygen/steam ratio (v/v) be 0.33 steam+oxygen mixture operate.For this target P WOR, this maximises the oxygen content in this reservoir.

Above-described embodiment also can be used for the range limits (oxygen in steam+oxygen mixture between 5-50 (v/v) %) confirming (and explanation) SAGDOXO.For the project of maturation, assuming that our ETOR=1.0MMBTU/bblB (SAGD is equivalent to SOR for about 3); Our initial bitumen saturation ratio is 0.75 to 0.90; And our PWOR target zone is 0.75 to 1.50.So, Figure 21 demonstrate oxygen content in oxygen/vapour mixture should about between 10-50% Bianization – and SAGD range limits consistent.

Although above-mentioned scope confirms that the limit of SAGDOX gas is the oxygen of (5-50 (v/v)) % in oxygen+vapour mixture, SAGDOXO strategy makes outside oxygen horizontal extension to original SAGDOX limit.Along with SAGDOXO method is ripe, ETOR will increase, because heat waste increases, and SAGDOXO methods and strategies determines the increase of oxygen level.Such as, Figure 22 is used, for S _io-0.8 and PWOR=1.0, when initial stage maturation (the prime maturity) of ETOR=1.0, the oxygen level of suggestion is the oxygen of in oxygen-vapour mixture about 25%.If ETOR rises to 2.0 (being equivalent to SOR ~ 6), then the oxygen level of advising is more than 50% in oxygen-vapour mixture, i.e. 60%O ₂– exceedes traditional SAGDOX target zone.

(9) SAGDOX operation strategy of the present invention is the oxygen level in gradual change steam+oxygen mixture, starts with low oxygen level, and finally there is no steam close to only injecting oxygen time end of lifetime (Fig. 2).This is intuitively, because oxygen is more cheap than steam, SAGDOXO method obtains this strategy automatically.During close to end of lifetime, the surface area being exposed to non-producing district can be high and draining angle little (Fig. 2).ETOR can climb until reach economic limit.For only oxygen, the ETOR up to about 16 is feasible.Along with ETOR increases, owing to producing more metabolic water and producing more connate water (relevant to the pitch of burning), the water/steam production of combustion parts increases.Figure 23 show only for the PWOR that burns to improve ETOR performance.For initial bitumen saturation ratio≤0.9, along with ETOR rises to more than 10, if the threshold value of good (steam) heat trnasfer is PWOR >=1.0, so do not need to inject any steam (namely steam is 0%).If loosen performance standard, for the end of lifetime SAGDOXO project of PWOR>0.5, as long as ETOR>=4, for S _io<0.9, we do not need to inject any steam.Only use oxygen (i.e. steam=0%, oxygen=100%) prospect, close to the SAGDOXO project of end of lifetime, guarantee minimize running cost (because oxygen is more cheap than the per unit energy of steam) and maximize ultimate recovery (i.e. reserves).

(10) Figure 24 shows for concrete case (S _io=0.8, PWOR target=1.0), how the oxygen level in injecting gas rises along with the increase of ETOR.At more than ETOR=8.0, do not need to inject steam.Injecting gas is only oxygen.In reservoir, enough steam is produced, to obtain PWOR=1.0 target by thermal evaporation connate water and by the steam of the direct generation of burning by using.

(11) Fig. 7 shows the change with ETOR and initial bitumen saturation ratio of transition point from steam+oxygen (SAGDOX) to only oxygen (ISC), assuming that PWOR=1.0 target.Be less than about for 0.5 for pitch saturation ratio, the connate water that there is enough gasifications adds that metabolic water is to meet the PWOR target of all ETOR values, need not inject any steam.

(12) if use the SAGDOXO method of PWOR goal systems to run into the poor district with low pitch saturation ratio (<0.6) and high connate water saturation (> 0.4), the method is also useful.When burning runs into poor district, produce water and PWOR (provisionally) rising.SAGDOXO remedial measure increases the oxygen content in feed gas (steam+oxygen).It reduce running cost and maintain PWOR target.When breaking in this district, oxygen level reduces.

(13) Figure 25 and table 5 shows the impact of SAGDOX and SAGDOXO on water circulation ratio (steam of recovered water/injection).Assuming that the yield of produced water treatment is 90%, if WRR is more than 1.1, so do not need supplementing water.As long as oxygen level exceedes about 10% in injecting gas, the method just to produce than required more water to keep steam to produce without any need for supplementary or fresh water.

some between SAGDOXO and SAGDOX are not all:

SAGDOX comprises a series of preferred oxygen concentration (5-50%, in steam+oxygen mixture); SAGDOXO extends this scope (unrestrictedly).

SAGDOX suggestion operations person can choose oxygen/vapour mixture; SAGDOXO provides the method for optimization oxygen/steam ratio.

SAGDOXO uses PWOR to carry out Optimal performance as target measurement value; SAGDOX does not have such measured value.

SAGDOXO automatic development strategy comes along with the ripe and gradual change steam injection of project; SAGDOX does not have so preferred.

SAGDOX always injects steam+oxygen mixture; SAGDOXO can be transformed into for high ETOR operation or the ISC method for poor bitumen reservoir.

some specific characteristics of SAGDOXO comprise:

Target, measurement (PWOR) are to optimize oxygen/vapour mixture composition.

Along with process aging and ETOR increase and automatic gradual change (reduce steam injection, increase oxygen).

Consider that pitch saturation ratio is as controlling and the key factor of optimization method.

The poor district (reducing vapor level until break in this district) run in dynamic response reservoir.

There is no fixing oxygen/steam ratio ranges; There is no limit.

Initial target >=1.0 of the PWOR of suggestion.

table 1

SACDDX: injecting gas character

Wherein

-mixture=steam+oxygen

-steam, 1000 BTU/1b

-oxygen, 480 BTU/SCP

table 2

sAGDOX combustion parts PWOR(maturation method)

Wherein

Entry is bblW/bblB

The connate water that 1=is combined with extraction pitch

The connate water that 2=is combined with the bituminous fuel of burning

3=metabolic water

··PWOR＝1+2+3

Metabolic water=0.056bbl/MMBTU

Fuel=coke (the CH of burning _.5)

table 3

sAGDOX vapor portion water balance

Wherein

Wh=well head; Sf=sand face

10% heat waste, wh to sf

The steam of all injections is plucked out of

Connate water is not had to be plucked out of

Steam, 1000BTU/lb; .35MMBTU/bbl

BblW=bbl water; BblB=bbl pitch

The WOR of PWOR=extraction

table 4

SAGDOX:PWOR(ETOR＝1.0)

Wherein

-PWOR=bbl water/bbl B

-PWOR=comprises PWOR (O ₂) table 2+PWOR (steam) table 3, distribute by the energy proportion of supply

-whole for ETOR, total=1MMBTU/bblB

table 5

sAGDOX:WRR (water circulation ratio)(ETOR=1.0)

Wherein

-entry is the steam of WRR (v/v)=recovered water/injection

-ETOR＝1MMBTU/bblB

-see table 4.3

table 6

sAGDOX combustion parts PWOR(end of lifetime)

Wherein

-entry is PWOR=bbl water/bbl pitch

-PWOR comprises the water be combined with the pitch+water of extraction

-metabolic water=.0562bbl/MMBTU

-for the ETOR of combustion parts, MMTBU/bbl

-fuel=coke (CH _.5) (Figure 18)

-O ₂heat, 480BTU/SCF

-drill bit fuel value=6MMBTU/bbl B

Therefore can make many changes to embodiments of the present invention and not deviate from its scope.Think that all scenario comprised in this article is all considered to unrestricted to explanation of the present invention.

Claims

1. recovered water and oil ratio rate (v/v) (" PWOR ") in hot intensified oil reduction (" EOR ") for controlling the purposes of described hot EOR.

2. purposes according to claim 1, wherein PWOR is for optimizing described hot EOR.

3., for SAGD (SAGDOX) method of the use injection oxygen of the hydrocarbon in recovery of hydrocarbons reservoir, described method comprises:

A () starts described SAGDOX technique under the first oxygen and steam ratio;

B () measures the recovered water relevant with steam ratio to described first oxygen and oil ratio rate (v/v)

PWOR；

C () regulates described oxygen and steam ratio to obtain predetermined PWOR; With

D () continues step (a) to (c) until obtain the target P WOR improving described hydrocarbon recovery ratio.

4., for SAGD (" the SAGDOX ") method of the use injection oxygen of recovery of hydrocarbons, wherein said SAGDOX method has about 19 to the steam and the oxygen ratio that are greater than zero.

5., for SAGD (" the SAGDOX ") method of the use injection oxygen of recovery of hydrocarbons, the oxygen that wherein said SAGDOX has and steam ratio are determined by recovered water and oil ratio rate (" PWOR ").

6. method according to claim 3, but wherein said PWOR is about 0.5 to until maximum value, makes the amount of oxygen close to zero is greater than zero.

7. method according to claim 6, wherein said PWOR is about 0.5 to 2.00, and the oxygen that described oxygen and steam ratio are about 0% to 100% compares steam.

8. method according to claim 6, wherein said PWOR is 1.0.

9. method according to claim 3, the oxygen content that wherein said oxygen has is 95-99.99 (v/v) %.

10. method according to claim 8, wherein said oxygen is oxygen-enriched air, and oxygen content is 21-95 (v/v) %.

11. methods according to claim 1, the described hydrocarbon in described hydrocarbon reservoir wherein to be exploited is pitch, and API density is less than 10, and original position viscosity is greater than 100,000cp.

12. methods according to claim 1, the described hydrocarbon in described hydrocarbon reservoir wherein to be exploited is mink cell focus, and API density is between 10 and 20, and original position viscosity is greater than 1,000cp.

13. purposes according to claim 1,2 or 3, wherein by changing described PWOR until maximize asphalt production rate to determine PWOR target.