CN108252697A - Method for producing petroleum - Google Patents

Abstract

The invention provides a method for exploiting petroleum, which comprises the following steps: and opening a horizontal well group according to the oil storage layer. And injecting steam into the horizontal well group to enable the oil reservoir to form a steam cavity. And (4) opening a vertical well according to the oil storage layer, and injecting carbon dioxide into the vertical well so as to discharge oil bodies in the oil storage layer through the horizontal well group. The method can effectively improve the yield of petroleum.

Description

The method for exploiting oil

Technical field

The present invention relates to technical field of petroleum extraction, in particular to a kind of method for exploiting oil.

Background technology

It is the effective of raising oil deposit of shallow-layer super heavy exploitation using dual horizontal well SAGD in existing technical field of petroleum extraction Technology compared with steam soak and steam drive development technology, has the advantage that daily oil production is high, gas oil ratio is high, recovery ratio is high.It is double Horizontal well SAGD exploitations are high to reservoir conditions requirement, and the SAGD well group horizontal segments existed between I, P well and above I wells every interlayer are employed The problems such as degree is low, and vapor chamber development is unbalanced, and well group is actually movably reduced with oil in place, causes production capacity not high.Further Ground, as the production time increases, remaining oil saturation continuously decreases, and the steam thermal efficiency reduces, and is faced with increasing vapour and does not increase production or lack The problem of volume increase, causes gas oil ratio relatively low, and auxiliaring effect can not be promoted further.

Invention content

It is a primary object of the present invention to provide a kind of method for exploiting oil, to solve in the prior art, oil production rate is not The problem of high.

To achieve these goals, according to an aspect of the invention, there is provided a kind of method for exploiting oil, method packet Include following steps：Horizontal well group is opened up according to oil reservoirs；Steam is injected in horizontal well group so that oil reservoirs form vapor chamber；Root Straight well is opened up according to oil reservoirs, carbon dioxide is injected in straight well so that the oil body of oil reservoirs is discharged by horizontal well group.

Further, horizontal well group is opened up to include the following steps：Horizontal production well is opened up, is opened above horizontal production well If horizontal steam injection well.

Further, steam is injected in horizontal well group to include the following steps：Steam is injected in horizontal steam injection well So that oil reservoirs form vapor chamber.

Further, vapor chamber is formed between the sandwiched area of oil reservoirs.

Further, straight well is opened up to include the following steps：Straight well is opened up in the sandwiched area for forming vapor chamber.

Further, straight well is opened up to include the following steps：Straight well is opened up in sandwiched area so that vapor chamber is formed in straight well Between horizontal steam injection well.

Further, carbon dioxide is injected in straight well to include the following steps：Carbon dioxide, titanium dioxide are injected in straight well Carbon is sprayed by spray-hole to sandwiched area, so that the oil body in sandwiched area is discharged by horizontal production well.

Further, spray-hole is located at the top of horizontal production well.

Further, carbon dioxide is injected in straight well to include the following steps：In straight well inject carbon dioxide until Carbon dioxide thermal insulation layer is formed on the top of vapor chamber.

Further, it is further comprising the steps of to open up straight well：Straight well is opened up in the side of the center line of horizontal well group.

It applies the technical scheme of the present invention, the method for the exploitation oil includes the following steps：Level is opened up according to oil reservoirs Well group.Steam is injected in horizontal well group so that oil reservoirs form vapor chamber.Straight well is opened up according to oil reservoirs, is injected in straight well Carbon dioxide is so that the oil body of oil reservoirs is discharged by horizontal well group.The production of oil can be effectively improved using this method Amount.

Description of the drawings

The accompanying drawings which form a part of this application are used to provide further understanding of the present invention, and of the invention shows Meaning property embodiment and its explanation do not constitute improper limitations of the present invention for explaining the present invention.In the accompanying drawings：

Fig. 1 shows straight well auxiliary SAGD notes CO according to the present invention₂Yield-increasing technology principle schematic.

Wherein, above-mentioned attached drawing is marked including the following drawings：

10th, horizontal well group；11st, horizontal production well；12nd, horizontal steam injection well；20th, vapor chamber；30th, straight well；31st, it sprays Hole.

Specific embodiment

It should be noted that in the absence of conflict, the feature in embodiment and embodiment in the application can phase Mutually combination.The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

It should be noted that term used herein above is merely to describe specific embodiment, and be not intended to restricted root According to the illustrative embodiments of the application.As used herein, unless the context clearly indicates otherwise, otherwise singulative It is also intended to include plural form, additionally, it should be understood that, when in the present specification using term "comprising" and/or " packet Include " when, indicate existing characteristics, step, operation, device, component and/or combination thereof.

It should be noted that term " first " in the description and claims of this application and above-mentioned attached drawing, " Two " etc. be the object for distinguishing similar, and specific sequence or precedence are described without being used for.It should be appreciated that it uses in this way Term can be interchanged in the appropriate case, so that presently filed embodiment described herein for example can be in addition to herein Sequence other than those of diagram or description is implemented.In addition, term " comprising " and " having " and their any deformation, it is intended that Be to cover it is non-exclusive include, for example, containing the process of series of steps or unit, method, system, product or equipment not Be necessarily limited to those steps clearly listed or unit, but may include not listing clearly or for these processes, side The intrinsic other steps of method, product or equipment or unit.

For ease of description, spatially relative term can be used herein, as " ... on ", " ... top ", " ... upper surface ", " above " etc., for describing such as a device shown in the figure or feature and other devices or spy The spatial relation of sign.It should be understood that spatially relative term is intended to comprising the orientation in addition to device described in figure Except different direction in use or operation.For example, if the device in attached drawing is squeezed, it is described as " in other devices It will be positioned as " under other devices or construction after the device of part or construction top " or " on other devices or construction " Side " or " under other devices or construction ".Thus, exemplary term " ... top " can include " ... top " and " in ... lower section " two kinds of orientation.The device can also other different modes positioning (being rotated by 90 ° or in other orientation), and And respective explanations are made in opposite description to space used herein above.

Now, the illustrative embodiments according to the application are more fully described with reference to the accompanying drawings.However, these are exemplary Embodiment can be implemented by many different forms, and should not be construed to be limited solely to embodiment party set forth herein Formula.It should be understood that these embodiments are provided so that disclosure herein is thoroughly and complete, and these are shown The design of example property embodiment is fully conveyed to those of ordinary skill in the art, in the accompanying drawings, for the sake of clarity, it is possible to expand The big thickness of layer and region, and make identical device is presented with like reference characters, thus they are retouched by omitting It states.

With reference to shown in Fig. 1, according to an embodiment of the invention, a kind of method for exploiting oil is provided.

Specifically, the method for the exploitation oil includes the following steps：Horizontal well group 10 is opened up according to oil reservoirs.In horizontal well Injection steam in group 10 is so that oil reservoirs form vapor chamber 20.Straight well 30 is opened up according to oil reservoirs, injects dioxy in straight well 30 Change carbon so that the oil body of oil reservoirs is discharged by horizontal well group 10.

In the present embodiment, CO is utilized₂Booster action improves oil displacement efficiency, improves heat utilization efficiency, reaches raising oil and gas Than increasing the purpose of economic benefit.The yield of oil can be effectively improved using this method.

Wherein, horizontal well group 10 is opened up to include the following steps：Horizontal production well 11 is opened up, in the top of horizontal production well 11 Open up horizontal steam injection well 12.It is enabled in this way in injection CO₂Under the action of, the consistency for hiding oil can be effectively reduced, So that it is that oil body can be quickly flowed into horizontal production well 11 under the gravity of itself to hide oil.

Steam is injected in horizontal well group 10 to include the following steps：Steam is injected in horizontal steam injection well 12 so that storage Oil reservoir forms vapor chamber 20.Wherein, vapor chamber 20 is formed between the sandwiched area (as shown in Figure 1A) of oil reservoirs.It sets in this way Tibetan oil yield can further be improved by putting.

Straight well 30 is opened up to include the following steps：Straight well 30 is opened up in the sandwiched area for forming vapor chamber 20.In sandwiched area Straight well 30 is opened up so that vapor chamber 20 is formed between straight well 30 and horizontal steam injection well 12.Titanium dioxide is injected in straight well 30 Carbon includes the following steps：Carbon dioxide is injected in straight well 30, carbon dioxide is sprayed by spray-hole 31 to sandwiched area, so that Oil body in sandwiched area is discharged by horizontal production well 11.Specifically, spray-hole 31 is located at the top of horizontal production well 11.

Carbon dioxide is injected in straight well 30 until forming carbon dioxide thermal insulation layer (B in such as Fig. 1 at the top of vapor chamber 20 Shown in).Utilize CO₂Heat-insulation and heat-preservation, demulsification drop is glutinous and the displacement of reservoir oil acts on, and further improves rate of oil production.Wherein, straight well 30 is opened up It is further comprising the steps of：Straight well 30 is opened up in the side of the center line of horizontal well group 10.

In the present embodiment, one kind is provided in straight well assists SAGD production processes, utilizes CO₂Booster action is improved and is driven Oily efficiency improves heat utilization efficiency, reaches raising gas oil ratio, increase the purpose of economic benefit.

Straight well auxiliary SAGD notes CO₂Yield-increasing technology is one and assists the SAGD thermals efficiency for straight well is improved, and improves gas oil ratio Yield-increasing technology.In straight well auxiliary SAGD production processes, after vapor chamber is extending transversely along top of oil horizon completion, steam and lid Layer contact, heat loss increase, at this time by the way of nitrogen injection, utilizes CO₂Heat-insulation and heat-preservation, demulsification drop is glutinous and the displacement of reservoir oil acts on, into One step improves rate of oil production, increases economic efficiency.

After straight well assists SAGD vapor chambers to top, CO is injected₂Gas utilizes CO₂Gas has non-condensing gas characteristic, leads Hot coefficient is relatively small, can reduce the heat transfer rate of steam overlying rock, significantly decreases thermal loss, therefore can reduce Steam consumption, the demand of non-condensing gas also only inject the 1% of vapour volume, so as to improve the thermal efficiency of SAGD exploitations.

Easily cause high temperature emulsion during viscous crude, super-viscous oil exploitation via steam injection, form water-in-oil type emulsion, greatly It is big to increase Crude viscosity, reduce the mobility of crude oil.CO₂Gas is soluble in oil and part is dissolved in the property (CO of water₂Gas is in original Solubility in oil is 3-9 times bigger than in water), make CO₂Diffusion coefficient of the gas in You Heshui is higher, and diffusion can Make CO₂Gas is redistributed in itself, and the water-in-oil type emulsion that exploitation via steam injection is formed is allowed to be destroyed, system is made to balance each other shape State is stablized and further reduces oil-water interfacial tension.CO simultaneously₂Not only it can be considered as a kind of boil-off gas, but also one can be regarded as Kind condensation gas.CO₂Gas can make C₁₀Above alkane liquefaction, therefore, for different type crude oil (thin oil, common heavy oil and Super-viscous oil), under different temperatures, pressure condition, CO₂Gas has the unlimitedly ability with crude oil mixed phase, can promote in crude oil Light hydrocarbons (C₂- C₃₀) extracted, so as to be substantially reduced residual oil saturation, reach better oil displacement efficiency.

Wherein, SAGD oil recovery techniques (Steam Assisted Gravity Drainage, abbreviation SAGD) are a kind of by steaming A bite straight well or a bite horizontal well injection oil reservoir of the vapour above the horizontal production well near oil reservoir bottom, the original heated Oil and steam condensate are from the oil production method of the horizontal well output of oil reservoir bottom.

SAGD is a cutting edge technology of international development super-viscous oil.Its theory is initially based on water filling and adopts salt principle, that is, notes Enter fresh water to dissolve solid salt in salt deposit, the big salting liquid of concentration flows downward since its density is big, and density is relatively small Aqueous solution float on above, by continuing to the water filling of salt deposit top, the continuous high concentration salt solutions in salt deposit lower part are produced.By this As soon as principle is applied to during heat extraction by steam injection, the concept of gravity drainage is produced.SAGD is exactly steam driving exploitation mode, i.e., High temperature, high-quality steam are continuously injected into steam injection well, develops vapor chamber first, in heated oil reservoir and keeps certain formation pressure (supplement stratum energy), crude oil is driven in producing well around, is then produced.

SAGD abbreviations steam assisted gravity drainage (Steam Assisted Gravity Drainage, abbreviation SAGD) is A kind of a bite straight well or a bite horizontal well injection oil reservoir by steam above the horizontal production well near oil reservoir bottom, quilt The crude oil and steam condensate of heating have high oil recovery ability, high oil from the oil production method of the horizontal well output of oil reservoir bottom Vapour is than, higher ultimate recovery and reduces inter-well interference, avoids altering the advantages of logical between too early well.

Frequently problem in SAGD oil recovery techniques SAGD：

1st, reservoir quality is poor than expected, and if oil saturation is than relatively low, water saturation is higher.

2nd, producing well well screen is shaked out destruction by channeling --- it is showed more so in the artesian well of non-armored pump.

3rd, jacking capacity is insufficient, and vaporium cannot advance downwardly --- particularly well section it is very long in the case of.

4th, vaporium hypotony, it is impossible to prevent water enchroachment (invasion).

5th, TRAJECTORY CONTROL level is low, and steam injection well and producing well horizontal segment hang down away from fluctuation greatly, be easy to cause flash distillation.

The crude oil that viscous crude is asphalitine and gum level is higher, viscosity is larger.Usually ground surface density be more than 0.943, Lower viscosity is more than the crude oil of 50 centipoises viscous crude.Because the density of viscous crude is big, also referred to as heavy oil.

Viscous crude, viscosity is more than 50 mpas or degassed crude viscosity is 1000~10000 millipascals under reservoir temperature The high viscosity heavy crude of second.For viscous crude in addition to viscosity is high, density is also high.Viscous crude is few containing light fraction, and colloid is high with bitumen content. The viscosity of viscous crude varies with temperature, and changes significantly, if temperature increases by 8~9 degrees Celsius, viscosity can reduce half.Therefore, to viscous crude Exploitation, conveying, multi-purpose heating power reduces its viscosity, such as steam driving, hot-oil circulation, combustion in situ.It is dilute that incorporation can also be used Oil, emulsification, addition activating agent reduce its viscosity.Under reservoir temperature, degassed crude viscosity is more than the crude oil of 10000 mpas Referred to as special heavy crude oil (very heavy oil).

Viscous crude is a kind of more sticky oil as its name suggests.Because of its viscosity height, density is big, external to be generally referred to as Heavy oil, we are accustomed to being referred to as viscous crude, this is named with respect to thin oil.The intuitive comparison of viscous crude and thin oil, we can see It is flowed as water to thin oil, and viscous crude is difficult flowing, caused by this is viscosity of thickened oil height, some viscosity of thickened oil are up to hundreds of Ten thousand mpas as " black mud ", can use spade, be picked up with hand.Said with the language of science, be exactly the mobility of viscous crude too Difference, oil sticky in this way are difficult to be produced from underground naturally.

In the oil exploitation in oil field, viscous crude has special high viscosity and high-solidification point characteristic, in development and application Various aspects all encounter some technical barriers.For production technique, colloid, asphalitine and long chain paraffin cause crude oil in reservoir It is deteriorated with the mobility in pit shaft, it is desirable that implement the tertiary oil recovery process of high investment.Height is viscous, the conveying of High viscosity crude is necessary Using more powerful pumping equipment, and in order to reach rational pump displacement, it is desirable that transport system is heated Or processing is diluted to crude oil.For refinery technology, the heavy metal in heavy oil can reduce rapidly the effect of catalyst, and And in order to which viscous crude is converted into fuel oil, it is also necessary to hydrogen is added in, is greatly increased so as to cause refinery cost, residual oil amount is big, sulphur, The difficult component content such as nitrogen, metal, acid is high and oil plant is reluctant the reason of refining viscous crude more.As it can be seen that the special nature of viscous crude Determine adopting, is defeated, refining what is necessarily carried out around the modification of the viscosity reduction pour point depression of viscous crude or modifying process for viscous crude.

Different DP technologies can be taken for the construction of the features such as viscosity of thickened oil is big and each oil reservoir.Heavy crude reservoir water drive is opened Technology is adopted mainly to include mechanical viscosity reduction, pit shaft heating, dilution viscosity reduction, chemical viscosity reduction, microbial single well stimulation, take out thick process matching Deng：Heavy crude reservoir thermal recovery technology mainly includes steam soak, steam drives, clump formula directional well and horizontal well, combustion in situ and Mating other technologies etc. with heavy crude heat extraction.

The difficult point of combustion in situ is that implementing process difficulty is big, is difficult to control underground combustion, while high pressure injection large quantity of air Cost again it is sufficiently expensive.And the chemical agent that chemical viscosity reduction method adds in causes stratum seriously to pollute to a certain extent.At present Both at home and abroad to viscous crude and high solidifying oil exploitation generally using thermal recovery mode, electric-heating technology is that an electricity is worn in hollow rod Cable, one end of cable are connected with the bottom end of hollow rod, apply exchange on the circuit being made of cable, hollow rod Electricity realizes heating, viscosity reducing by the hollow rod heated to viscous crude or the high heat transfer for coagulating oil.Compared with other technologies, tool There is higher efficiency, and the process operation is fairly simple, expense is relatively low, recovers the oil both economical.Therefore with apparent Superiority is used widely in many oil fields of China.

Heavy oil development is global hang-up.In today that Chinese energy is in short supply, viscous crude resource is undoubtedly China can not One of energy of ignorance.Most of heavy crude reservoir of China is essentially all small fault block heavy crude reservoir, and this kind of oil reservoir belongs to low product Position petroleum resources, crude oil property is poor, and exploitation, oil recovery, surface gathering and transferring and intractability are big.

In heavy crude producing, since viscosity is excessively high, paraffin content is big so that the oil flow channel of oil pipe reduces, rod string Uplink and downlink resistance increases, and when down stroke horse head easily occurs and " fights " phenomenon, and beam rating increases during upstroke, can make when serious Sucker rod is stuck in oil pipe or even to cause the down-hole accident of rod broken.In addition, for the relatively low well of reservoir temperature, Standing valve for oil-well pump, standing valve cover and its with lower portion since pressure is low, be easily formed stifled well in process of production, and will quilt Compel to carry out well workover.

For electric submersible pump producing well, since electric immersible pump well discharge capacity is big, pressure is low at suction inlet, when reservoir temperature is relatively low When, herein easy wax deposition and cause blade guiding wheel runner block, drilling fluid resistance increase, decline the discharge capacity of pump, while electricity can be made Machine load increases, serious that motor is caused often to shut down, and prevents electric pump unit from running well.

In short, there are many difficulties in the recovery process of viscous crude, since the property of viscous crude causes the down-hole accident in exploitation And its expense, cost for oil production can be made significantly to increase.Therefore, the research of reducing thick oil viscosity recovery method is for reducing down-hole accident Occur and reduction thickened oil recovery cost is of great significance.

Than that described above, it is also necessary to which explanation is " one embodiment " spoken of in the present specification, " another implementation Example ", " embodiment " etc. refer to that the specific features, structure or the feature that combine embodiment description are included in the application summary Property description at least one embodiment in.It is not centainly to refer to same reality that statement of the same race, which occur, in multiple places in the description Apply example.Furthermore, it is understood that when describing a specific features, structure or feature with reference to any embodiment, what is advocated is knot Other embodiment is closed to realize that this feature, structure or feature are also fallen within the scope of the present invention.

In the above-described embodiments, it all emphasizes particularly on different fields to the description of each embodiment, there is no the portion being described in detail in some embodiment Point, it may refer to the associated description of other embodiment.

The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, that is made any repaiies Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.

Claims (10)

1. A kind of 1. method for exploiting oil, which is characterized in that the described method comprises the following steps：

   Horizontal well group (10) is opened up according to oil reservoirs；

   The injection steam in the horizontal well group (10) is so that the oil reservoirs form vapor chamber (20)；

   Straight well (30) is opened up according to oil reservoirs, injection carbon dioxide is so that the oil body of the oil reservoirs leads in the straight well (30) Cross horizontal well group (10) discharge.
2. 2. according to the method described in claim 1, include the following steps it is characterized in that, opening up the horizontal well group (10)：

   Horizontal production well (11) is opened up, horizontal steam injection well (12) is opened up above the horizontal production well (11).
3. 3. according to the method described in claim 2, it is characterized in that, the injection steam includes in the horizontal well group (10) Following steps：

   The steam is injected in the horizontal steam injection well (12) so that the oil reservoirs form vapor chamber (20).
4. 4. according to the method described in claim 3, it is characterized in that, the vapor chamber (20) is formed in the interlayer of the oil reservoirs Between region.
5. 5. according to the method described in claim 4, include the following steps it is characterized in that, opening up the straight well (30)：

   The straight well (30) is opened up in the sandwiched area for forming the vapor chamber (20).
6. 6. according to the method described in claim 5, include the following steps it is characterized in that, opening up the straight well (30)：

   The straight well (30) is opened up in the sandwiched area so that the vapor chamber (20) be formed in the straight well (30) with it is described Between horizontal steam injection well (12).
7. 7. according to the method described in claim 4, it is characterized in that, the injection carbon dioxide includes in the straight well (30) Following steps：

   The injection carbon dioxide in the straight well (30), the carbon dioxide are sprayed by spray-hole (31) to the interlayer Region, so that the oil body in the sandwiched area is discharged by the horizontal production well (11).
8. 8. the method according to the description of claim 7 is characterized in that the spray-hole (31) is positioned at the horizontal production well (11) Top.
9. 9. according to the method described in claim 1, it is characterized in that, the injection carbon dioxide includes in the straight well (30) Following steps：

   The injection carbon dioxide in the straight well (30) until formed at the top of the vapor chamber (20) carbon dioxide every Thermosphere.
10. 10. according to the method described in claim 1, it is characterized in that, to open up the straight well (30) further comprising the steps of：

    The straight well (30) is opened up in the side of the center line of the horizontal well group (10).