CN112746830A - Oil reservoir two-stage branch SAGD reservoir deep expansion oil extraction method - Google Patents
Oil reservoir two-stage branch SAGD reservoir deep expansion oil extraction method Download PDFInfo
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- 238000010796 Steam-assisted gravity drainage Methods 0.000 title claims abstract description 54
- 238000000605 extraction Methods 0.000 title claims abstract description 23
- 238000010793 Steam injection (oil industry) Methods 0.000 claims abstract description 143
- 238000004519 manufacturing process Methods 0.000 claims abstract description 122
- 230000002093 peripheral effect Effects 0.000 claims abstract description 21
- 239000003921 oil Substances 0.000 claims description 112
- 239000010779 crude oil Substances 0.000 claims description 21
- 238000002347 injection Methods 0.000 claims description 19
- 239000007924 injection Substances 0.000 claims description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 15
- 230000015572 biosynthetic process Effects 0.000 claims description 10
- 238000010521 absorption reaction Methods 0.000 claims description 8
- 238000011084 recovery Methods 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 6
- 238000005406 washing Methods 0.000 claims description 4
- 239000012530 fluid Substances 0.000 claims 2
- 230000000694 effects Effects 0.000 abstract description 8
- 239000010410 layer Substances 0.000 description 15
- 238000004891 communication Methods 0.000 description 5
- 239000011229 interlayer Substances 0.000 description 5
- 239000007788 liquid Substances 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000003027 oil sand Substances 0.000 description 1
- 238000013486 operation strategy Methods 0.000 description 1
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- 238000012216 screening Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
- E21B43/2406—Steam assisted gravity drainage [SAGD]
- E21B43/2408—SAGD in combination with other methods
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/08—Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/20—Displacing by water
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
- E21B43/2405—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection in association with fracturing or crevice forming processes
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/30—Specific pattern of wells, e.g. optimising the spacing of wells
- E21B43/305—Specific pattern of wells, e.g. optimising the spacing of wells comprising at least one inclined or horizontal well
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Abstract
The invention provides a deep expansion oil extraction method for an SAGD reservoir of a secondary branch of an oil reservoir. The oil reservoir secondary branch SAGD reservoir deep capacity-expansion oil extraction method comprises the following steps: determining an available oil reservoir; respectively carrying out primary capacity expansion on a peripheral reservoir of a steam injection horizontal well of an available oil reservoir and a peripheral reservoir of a production horizontal well; performing secondary expansion on a peripheral reservoir of a steam injection horizontal well of the available oil reservoir and a peripheral reservoir of a production horizontal well respectively; respectively carrying out steam circulation on the steam injection horizontal well and the production horizontal well, wherein the circulating pressure of the steam circulation is greater than the minimum main stress of the stratum, so that the primary branch communicated with the secondary branch and the production horizontal well form an oil drainage channel; and adjusting the pressure difference between the steam injection horizontal well and the production horizontal well so that the pressure of the steam injection horizontal well is greater than that of the production horizontal well, and carrying out SAGD production. The invention solves the problems of low oil extraction speed of a non-homogeneous reservoir and poor residual oil extraction effect in the prior art.
Description
Technical Field
The invention relates to the field of oil exploitation, in particular to a deep expansion oil extraction method for an SAGD reservoir of a secondary branch of an oil reservoir.
Background
The SAGD technology, namely the steam assisted gravity drainage technology, is invented by professor Bulter in Canada in 1978, and is successfully applied to heavy oil reservoirs in Canada oil sand mining areas, Liaohe oil fields in China, Xinjiang oil fields and the like. The main principle of the double-horizontal-well SAGD is that 2 vertical parallel horizontal wells are arranged at the bottom of an oil layer, steam is continuously injected into the oil layer from an upper horizontal well to heat the oil layer and crude oil, a steam cavity is continuously expanded to exchange heat with the crude oil in the oil layer, the heated and viscosity-reduced crude oil and steam condensate water flow downwards under the action of gravity, and the crude oil and the steam condensate water are extracted from a horizontal production horizontal well at the lower part of the oil layer. Under the injection and production mode, crude oil is mainly drained under the action of gravity, when the vertical direction meets the seepage barriers such as the interlayer, the expansion of the steam cavity is seriously restricted, the drainage efficiency is reduced, and the whole production effect is deteriorated. Aiming at the exploitation of a thick oil reservoir of a heterogeneous reservoir, a secondary branch steam injection horizontal well SAGD is provided, compared with a primary branch SAGD, the branch of the secondary branch is longer in extension and wider in swept crude oil area, but no secondary branch SAGD matched operation strategy exists at present, and the secondary branch effect is not obvious.
Therefore, the problems of low oil extraction speed of the heterogeneous reservoir and poor residual oil extraction effect exist in the prior art.
Disclosure of Invention
The invention mainly aims to provide a deep expansion oil extraction method for an SAGD reservoir of a secondary branch of an oil reservoir, which aims to solve the problems of low oil extraction speed and poor residual oil extraction effect of a non-homogeneous reservoir in the prior art.
In order to achieve the above object, according to one aspect of the present invention, there is provided a method for deep volume-expanded oil production of a SAGD reservoir of a reservoir secondary branch, comprising: determining an available oil reservoir; respectively carrying out primary capacity expansion on a peripheral reservoir of a steam injection horizontal well of an available oil reservoir and a peripheral reservoir of a production horizontal well; performing secondary expansion on a peripheral reservoir of a steam injection horizontal well of the available oil reservoir and a peripheral reservoir of a production horizontal well respectively; respectively carrying out steam circulation on the steam injection horizontal well and the production horizontal well, wherein the circulating pressure of the steam circulation is greater than the minimum main stress of the stratum, so that the primary branch communicated with the secondary branch and the production horizontal well form an oil drainage channel; and adjusting the pressure difference between the steam injection horizontal well and the production horizontal well so that the pressure of the steam injection horizontal well is greater than that of the production horizontal well, and carrying out SAGD production.
Furthermore, a plurality of first-stage branches are arranged in the length direction of the steam injection horizontal well, and at least one second-stage branch is arranged on one side, far away from the steam injection horizontal well, of the plurality of first-stage branches.
Furthermore, the distance between each point on the first-stage branch and the horizontal direction of the steam injection horizontal well is less than or equal to 20 meters, the distance between each point on the first-stage branch and the vertical direction of the steam injection horizontal well is less than or equal to 5 meters, the length of the steam injection horizontal well is greater than or equal to 400 meters and less than or equal to 600 meters, the length of the first-stage branch is greater than or equal to 50 meters and less than or equal to 100 meters, and the included angle between the first-stage branch and the steam injection horizontal well is greater than or equal to 0 degree and less than or.
Furthermore, the distance between each point on the secondary branch and the horizontal direction of the steam injection horizontal well is less than or equal to 20 meters, the distance between each point on the secondary branch and the vertical direction of the steam injection horizontal well is less than or equal to 5 meters, the length of the secondary branch is more than or equal to 50 meters and less than or equal to 100 meters, and the included angle between the secondary branch and the primary branch is more than or equal to 0 degree and less than or equal to 90 degrees.
Furthermore, before expanding the volume of the reservoir around the steam injection horizontal well and the reservoir around the production horizontal well, the steam injection horizontal well and the production horizontal well need to be washed under pressure, and in the process of washing under pressure, the pressure of ground return liquid and the water absorption capacity of an oil layer of an available oil reservoir need to be monitored, the pressure of the ground return liquid is always smaller than 1MPa, and the water absorption capacity of the oil layer of the available oil reservoir is always smaller than 60L/min.
Further, in the process of expanding the reservoirs around the steam injection horizontal well and the production horizontal well, adjusting the steam injection speed of the steam injection horizontal well to be between 50L/min and 80L/min, adjusting the difference between the bottom pressure of the steam injection horizontal well and the minimum principal stress of the stratum to be less than 0.5MPa, and adjusting the difference between the fracture pressure of the stratum and the bottom pressure of the steam injection horizontal well to be more than 0.5 MPa.
Further, before expanding the volume of the reservoir around the steam injection horizontal well and the reservoir around the production horizontal well, the production horizontal well needs to be temporarily blocked or closed.
Further, the steam cycle is an isobaric injection steam cycle.
Further, before steam circulation is carried out on the steam injection horizontal well and the production horizontal well, uniform isobaric circulation preheating is respectively carried out on the steam injection horizontal well and the production horizontal well, steam injection pressure of the steam injection horizontal well is the same as that of the bottom of an available oil reservoir, and the difference between the steam injection pressure and the formation pressure is less than or equal to 0.5 MPa.
Furthermore, when the primary branch communicated with the secondary branch and the production horizontal well form an oil drainage channel, the viscosity of crude oil between the steam injection horizontal well and the production horizontal well is reduced to 1000 mPa.s, the steam injection pressure is greater than the minimum principal stress of the stratum, the steam injection pressure is less than 0.5MPa of the fracture pressure of the stratum, and the extraction-injection ratio of an available oil reservoir is between 0.80 and 0.85.
Further, when the sum of the expansion radius of the steam injection horizontal well and the expansion radius of the production horizontal well is equal to the distance between the steam injection horizontal well and the production horizontal well, stopping expanding the peripheral reservoirs of the steam injection horizontal well and the production horizontal well, continuously injecting water into the steam injection horizontal well, and stewing the production horizontal well when the water injection temperature is between 70 and 80 ℃.
By applying the technical scheme of the invention, the main well and the reservoir around the branch track are reconstructed by the deep expansion of the branch steam injection well, a foundation is provided for crude oil around the branch to be used, the oil drainage channel of the expansion zone around the branch track is established by controlling the circulating preheating pressure, the steam sweep range of the multi-branch SAGD is enhanced, the oil extraction speed is improved, and the problems that the oil extraction speed of the heterogeneous reservoir is low and the residual oil above the interlayer is difficult to be used are solved.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic diagram showing a reservoir structure of primary capacity expansion in a deep capacity expansion oil recovery method of a reservoir secondary branch SAGD reservoir according to an embodiment of the invention;
FIG. 2 is a schematic diagram showing a reservoir structure of secondary expansion in a deep expansion oil recovery method of a reservoir secondary branch SAGD reservoir according to an embodiment of the invention;
FIG. 3 shows a flow chart of the deep extended oil production method of the SAGD reservoir of the secondary branch of the reservoir.
Wherein the figures include the following reference numerals:
10. steam injection horizontal wells; 11. a first-stage branch; 12. secondary branching; 20. producing a horizontal well; 30. a dilatation belt.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
In the present invention, unless specified to the contrary, use of the terms of orientation such as "upper, lower, top, bottom" or the like, generally refer to the orientation as shown in the drawings, or to the component itself in a vertical, perpendicular, or gravitational orientation; likewise, for ease of understanding and description, "inner and outer" refer to the inner and outer relative to the profile of the components themselves, but the above directional words are not intended to limit the invention.
In order to solve the problems of low oil extraction speed of a non-homogeneous reservoir and poor residual oil extraction effect in the prior art, the application provides a deep expansion oil extraction method of an SAGD reservoir of a secondary branch of an oil reservoir.
As shown in fig. 1 to fig. 2, the method for deep volume-expanded oil recovery of an SAGD reservoir of a reservoir secondary branch in the present application includes: determining an available oil reservoir; respectively carrying out primary capacity expansion on the peripheral reservoir of the steam injection horizontal well 10 of the available oil reservoir and the peripheral reservoir of the production horizontal well 20; performing secondary capacity expansion on a peripheral reservoir of the steam injection horizontal well 10 of the available oil reservoir and a peripheral reservoir of the production horizontal well 20 respectively; respectively performing steam circulation on the steam injection horizontal well 10 and the production horizontal well 20, wherein the circulating pressure of the steam circulation is greater than the minimum main stress of the stratum, so that the primary branch 11 communicated with the secondary branch 12 and the production horizontal well 20 form an oil drainage channel; and adjusting the pressure difference between the steam injection horizontal well 10 and the production horizontal well 20 so that the pressure of the steam injection horizontal well 10 is greater than that of the production horizontal well 20, and performing SAGD production. And in the SAGD production process, adjusting injection and production parameters of the multi-branch SAGD well group until the production is finished.
By using the deep expansion oil extraction method of the secondary branch SAGD reservoir of the oil reservoir, the main well and the reservoir around the branch track are transformed through deep expansion of the branch steam injection well, a foundation is provided for crude oil around the branch to be used, the oil drainage channel of the expansion zone 30 around the branch track is established by controlling the circulating preheating pressure, the steam wave range of multi-branch SAGD is increased, the oil extraction speed is improved, and the problems that the oil extraction speed of the heterogeneous reservoir is low and the residual oil above the interlayer is difficult to be used are solved.
It should be noted that the SAGD well in this application includes a steam injection horizontal well 10 and a production horizontal well 20. And the secondary expansion is to carry out deep expansion on the basis of primary expansion.
Specifically, a plurality of first-stage branches 11 are arranged in the length direction of the steam injection horizontal well 10, and at least one second-stage branch 12 is arranged on one side, away from the steam injection horizontal well 10, of the plurality of first-stage branches 11. It should be noted that in the present application, the first-stage branch 11 may be located on both sides of the main borehole of the steam injection horizontal well 10.
Optionally, the distance between each point on the first-stage branch 11 and the horizontal direction of the steam injection horizontal well 10 is less than or equal to 20 meters, the distance between each point on the first-stage branch 11 and the vertical direction of the steam injection horizontal well 10 is less than or equal to 5 meters, the length of the steam injection horizontal well 10 is greater than or equal to 400 meters and less than or equal to 600 meters, the length of the first-stage branch 11 is greater than or equal to 50 meters and less than or equal to 100 meters, and the included angle between the first-stage branch 11 and the steam injection horizontal well 10 is greater than or equal to 0 degrees and less.
Optionally, the distance between each point on the secondary branch 12 and the horizontal direction of the steam injection horizontal well 10 is less than or equal to 20 meters, the distance between each point on the secondary branch 12 and the vertical direction of the steam injection horizontal well 10 is less than or equal to 5 meters, the length of the secondary branch 12 is greater than or equal to 50 meters and less than or equal to 100 meters, and the included angle between the secondary branch 12 and the primary branch 11 is greater than or equal to 0 degree and less than or equal to 90 degrees.
Specifically, before expanding the volume of the reservoir around the steam injection horizontal well 10 and the reservoir around the production horizontal well 20, the steam injection horizontal well 10 and the production horizontal well 20 need to be washed under pressure, and in the process of washing under pressure, the pressure of ground return liquid and the water absorption capacity of an oil layer of an available oil reservoir need to be monitored, the pressure of the ground return liquid is always smaller than 1MPa, and the water absorption capacity of the oil layer of the available oil reservoir is always smaller than 60L/min. If the initial water absorption capacity is significantly higher than 60L/min, natural fractures may exist in the oil layer, and at this time, a plugging treatment is required. And if the water absorption in the test injection process is normal, entering a normal expansion stage.
Specifically, in the process of expanding the reservoirs around the steam injection horizontal well 10 and the production horizontal well 20, the steam injection speed of the steam injection horizontal well 10 is adjusted to be 50L/min-80L/min, and the difference between the bottom hole pressure of the steam injection horizontal well 10 and the minimum main stress of the stratum is adjusted to be less than 0.5 MPa. The pressure is strictly controlled at this stage, the pressure is taken as a main control parameter, the injection amount is taken as an auxiliary control parameter, and the bottom hole pressure is slowly increased, so that the purposes of increasing the water saturation around the well and improving the physical uniformity around the well are achieved.
Specifically, the difference between the fracture pressure of the adjusted formation and the bottom hole pressure of the steam injection horizontal well 10 is greater than 0.5 MPa. The bottom hole pressure is further improved by improving the injection amount, the expansion area range around the steam injection horizontal well 10 and the production horizontal well 20 is gradually enlarged, the expansion radius is analyzed and calculated by combining real-time construction data, the actual deviation condition of a well rail and the physical property change of a well piece reservoir layer are comprehensively considered, and the expansion range is controlled.
Specifically, it is necessary to temporarily block or shut down the production horizontal well 20 before expanding the reservoirs around the steam injection horizontal well 10 and the production horizontal well 20. And continuously injecting steam into the steam injection horizontal well 10 at the moment to improve the bottom hole pressure of the steam injection horizontal well 10 to enable the bottom hole pressure to be close to the stratum fracture pressure, and performing deep expansion on the reservoir around the branch of the steam injection horizontal well 10 and above the main well hole.
Specifically, the steam cycle is an isobaric injection steam cycle.
Specifically, before steam circulation is carried out on the steam injection horizontal well 10 and the production horizontal well 20, uniform isobaric circulation preheating is respectively carried out on the steam injection horizontal well 10 and the production horizontal well 20, the steam injection pressure of the steam injection horizontal well 10 is the same as that of the bottom of an available oil reservoir, and the difference between the steam injection pressure and the formation pressure is less than or equal to 0.5 MPa. In this case, the injection/withdrawal ratio needs to be controlled to about 1.0. By uninterrupted heat transfer. Areas with higher temperature and lower crude oil viscosity are gradually formed near the steam injection horizontal well 10 and the production horizontal well 20, and an oil drainage channel between the expansion zone 30 around the branch and the main well bore is established.
Specifically, when an oil drainage channel is formed by a first-stage branch 11 and a production horizontal well 20 which are communicated with a second-stage branch 12, a steam injection horizontal well 10 and the production horizontal well 20 are subjected to balanced pressurization preheating, at this stage, along with the continuous expansion of a high-temperature region near a horizontal section shaft, the viscosity of crude oil between the steam injection horizontal well 10 and the production horizontal well 20 is reduced to 1000mPa · s, the crude oil between wells has certain flow capacity, the operating pressures of the steam injection horizontal well 10 and the production horizontal well 20 are increased in a balanced and gradual mode, the steam injection pressure is greater than the minimum principal stress of a stratum, the steam injection pressure is less than 0.5MPa of the fracture pressure of the stratum, and the available oil reservoir extraction-injection ratio is between 0.80 and 0.85. Meanwhile, the temperature of the steam cavity is further increased, the viscosity of crude oil is increased, and the flow of the crude oil is promoted.
Specifically, when the sum of the expansion radius of the steam injection horizontal well 10 and the expansion radius of the production horizontal well 20 is equal to the distance between the steam injection horizontal well 10 and the production horizontal well 20, the expansion of the peripheral reservoir of the steam injection horizontal well 10 and the peripheral reservoir of the production horizontal well 20 is stopped, water is continuously injected into the steam injection horizontal well 10, the water injection temperature is 70-80 ℃, and the production horizontal well 20 is shut down. At this time, in order to determine the communication condition between the steam injection horizontal well 10 and the production horizontal well 20, a plurality of temperature detection points need to be set in the horizontal section of the production horizontal well 20, and after the steam injection horizontal well 10 is communicated with the production horizontal well 20, water in the steam injection horizontal well 10 enters the production horizontal well 20, so that the plurality of temperature detection points detect temperature changes. Therefore, when the number of temperature detection points at which the temperature change occurs exceeds 80% of the total number, communication between the steam injection horizontal well 10 and the production horizontal well 20 is determined.
It should be noted that an oil drainage channel is formed between the expansion zone 30 and the production horizontal well 20, and when SAGD production is performed, a micro-pressure difference can be gradually established between the steam injection horizontal well 10 and the production horizontal well 20, and the maximum pressure difference is controlled within 0.5 MPa. At this time, the crude oil around the first-stage branch 11 and the second-stage branch 12 starts to flow to the production horizontal well 20, so that an oil drainage channel is gradually formed between the expansion zone 30 around the branches and the production horizontal well 20, and then the communication judgment is performed.
And after the communication judgment meets the SAGD production transferring condition, transferring to SAGD production, and adjusting injection and production parameters of the multi-branch SAGD well group until the production is finished.
As shown in fig. 3, a flow diagram of the oil reservoir two-stage branch SAGD reservoir depth expansion oil extraction method in the present application is that, firstly, an available oil reservoir is determined, the reservoirs around the shafts of the steam injection horizontal well 10 and the production horizontal well 20 are expanded, then, the reservoirs around the branch of the steam injection horizontal well 10 and above the main well bore are subjected to depth expansion, steam injection equal-pressure circulation is simultaneously performed on the branch steam injection wells (i.e., the steam injection horizontal well 10, the first-stage branch 11, and the second-stage branch 12) and the production horizontal well 20, a micro-pressure difference is established between the branch steam injection well and the production horizontal well 20 until an oil drainage channel is formed between the expansion zone 30 around the first-stage branch 11 and the second-stage branch 12 and the production horizontal well 20, and SAGD production is transferred.
In one embodiment of the application, crude oil reservoir screening is firstly carried out, the buried depth of a selected oil layer is 480m, the thickness of a continuous oil layer is 25m, the porosity of the oil layer is 0.32, the horizontal permeability is 1400mD, the ratio of the vertical permeability to the horizontal permeability is 0.7, the oil saturation is 0.72, the oil layer is formed by discontinuous mudstone in local development, and the viscosity of degassed crude oil is 3.8 ten thousand centipoise at the temperature of 50 ℃.
The SAGD well distance of the oil reservoir is 70m, the horizontal section length is 450m, the production horizontal well 20 is 2m away from the bottom of the oil reservoir, the steam injection horizontal well 10 is 5m away from the production horizontal well 20, the steam injection well is a multilateral well, 4 branches are distributed on two sides of a main well hole of the steam injection horizontal well 10 in a staggered mode, extend obliquely upwards at a certain angle with the main well hole, the length of a single branch is 100m, the maximum offset distance of the branch section on the plane from the main well hole is 20m, and the maximum offset distance of the branch section on the vertical direction from the main well hole is 5 m. Each primary branch 11 extends a secondary branch 12, extends along the main borehole direction at an angle of 0-90 degrees with the primary branch 11, each secondary branch 12 is 100m in length and parallel to the main borehole, and the maximum offset distance of the secondary branch 12 and the plane of the main borehole in the vertical direction is smaller than or equal to the maximum offset distance of the primary branch 11.
Firstly, carrying out shaft low-pressure expansion on a steam injection horizontal well 10 and a production horizontal well 20, wherein the net injection speed is about 70L/min, and the maximum bottom hole pressure is greater than the minimum main stress of 0.3 MPa; and then, further improving the bottom pressure, wherein the highest pressure is lower than the fracture pressure by 0.5MPa, and stopping operation when the sum of the calculated expansion radiuses is equal to the distance between the two wells.
Temporarily plugging or closing the production horizontal well 20, continuously injecting into a steam injection well, improving the bottom hole pressure of the steam injection horizontal well 10 to be close to the stratum fracture pressure, and performing depth expansion on reservoirs around the branch of the steam injection horizontal well 10 and above a main well hole.
The branch steam injection horizontal well 10 and the production horizontal well 20 are subjected to uniform isobaric circular preheating, the steam injection pressure of the steam injection well and the bottom steam injection pressure of the production horizontal well 20 are kept consistent and are both larger than the formation pressure by 0.5MPa, the injection-production ratio is controlled to be about 1.0, when the crude oil viscosity between the steam injection horizontal well 10 and the production horizontal well 20 is gradually reduced to about 1000 mPa.s, the bottom operation pressures of the steam injection horizontal well 10 and the production horizontal well 20 are started to be uniformly and gradually increased and are smaller than the formation fracture pressure by 0.5MPa, and the production-injection ratio is controlled to be 0.80-0.85, so that the temperature of a steam cavity is further increased, the crude oil viscosity is reduced, and the crude oil.
Gradually establishing micro-pressure difference between the branch steam injection horizontal well 10 and the production horizontal well 20, controlling the maximum pressure difference to be 0.5MPa, then performing communication judgment, switching to SAGD production after conditions are met, and adjusting injection and production parameters of the multi-branch SAGD well group until the production is finished.
Compared with the conventional SAGD, the peak oil production is increased to 38t/d from 25t/d, the oil recovery speed at the platform stage is increased by 60%, the oil recovery rate is increased by 8.0%, and the oil-gas ratio is increased by 0.04.
From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:
1. the multi-branch SAGD branch well has the advantages that the restriction of the interlayer on SAGD is weakened, the branch effect can be strengthened by carrying out reservoir expansion on the branch well, the influence range of the branch track is enlarged, the development speed of a steam cavity is increased, and the oil drainage area of the steam cavity is increased;
2. the operation is carried out according to a conventional SAGD development mode, the secondary branch SAGD branch only has the function of steam injection, an effective oil drainage channel is difficult to form, and the branching function is not obvious; and after the SAGD reservoir bed of the secondary branch is subjected to deep expansion, high-pressure circulation is carried out, so that an oil drainage channel can be established between the secondary branch and a production well, the oil drainage area is increased, the steam sweep speed is accelerated, residual oil above the interlayer is effectively used, and the oil extraction speed of the strong heterogeneous reservoir bed is greatly improved.
It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (11)
1. A deep expansion oil extraction method for an SAGD reservoir of a secondary branch of an oil reservoir is characterized by comprising the following steps:
determining an available oil reservoir;
respectively carrying out primary capacity expansion on a peripheral reservoir of a steam injection horizontal well (10) and a peripheral reservoir of a production horizontal well (20) of the available oil reservoir;
performing secondary expansion on a peripheral reservoir of the steam injection horizontal well (10) and a peripheral reservoir of the production horizontal well (20) of the available oil reservoir respectively;
respectively performing steam circulation on the steam injection horizontal well (10) and the production horizontal well (20), wherein the circulating pressure of the steam circulation is greater than the minimum main stress of a stratum, so that a primary branch (11) communicated with a secondary branch (12) and the production horizontal well (20) form an oil drainage channel;
and adjusting the pressure difference between the steam injection horizontal well (10) and the production horizontal well (20) so that the pressure of the steam injection horizontal well (10) is greater than that of the production horizontal well (20), and performing SAGD production.
2. The method for deep-expansion oil production of an SAGD reservoir of a reservoir secondary branch according to claim 1, wherein a plurality of the primary branches (11) are arranged in the length direction of the steam injection horizontal well (10), and at least one secondary branch (12) is arranged on one side, away from the steam injection horizontal well (10), of the primary branches (11).
3. The deep-expansion oil production method for the SAGD reservoir stratum of the oil reservoir secondary branch according to claim 2, wherein the distance between each point on the primary branch (11) and the horizontal direction of the steam injection horizontal well (10) is less than or equal to 20 meters, the distance between each point on the primary branch (11) and the vertical direction of the steam injection horizontal well (10) is less than or equal to 5 meters, the length of the steam injection horizontal well (10) is greater than or equal to 400 meters and less than or equal to 600 meters, the length of the primary branch (11) is greater than or equal to 50 meters and less than or equal to 100 meters, and the included angle between the primary branch (11) and the steam injection horizontal well (10) is greater than or equal to 0 degrees and less than or equal to 90 degrees.
4. The method for deep volume-expanding oil production of an SAGD reservoir of a reservoir as claimed in claim 2, wherein the distance between each point on the secondary branch (12) and the horizontal direction of the steam injection horizontal well (10) is 20 meters or less, the distance between each point on the secondary branch (12) and the vertical direction of the steam injection horizontal well (10) is 5 meters or less, the length of the secondary branch (12) is 50 meters or more and 100 meters or less, and the included angle between the secondary branch (12) and the primary branch (11) is 0 degree or more and 90 degrees or less.
5. The deep expansion oil production method of the SAGD reservoir stratum of the secondary branch of the oil reservoir as claimed in claim 1, wherein before expanding the peripheral reservoir of the steam injection horizontal well (10) and the peripheral reservoir of the production horizontal well (20), pressure well washing needs to be carried out on the steam injection horizontal well (10) and the production horizontal well (20), and in the pressure well washing process, the pressure of ground return fluid and the water absorption capacity of an oil layer of the available oil reservoir need to be monitored, the pressure of the ground return fluid is always smaller than 1MPa, and the water absorption capacity of the oil layer of the available oil reservoir is always smaller than 60L/min.
6. The deep dilatation oil production method of the SAGD reservoir of the reservoir secondary branch as claimed in claim 1, wherein in the process of dilatation of the reservoir around the steam injection horizontal well (10) and the reservoir around the production horizontal well (20), the steam injection speed of the steam injection horizontal well (10) is adjusted to be 50L/min-80L/min, the difference between the bottom hole pressure of the steam injection horizontal well (10) and the minimum principal stress of the formation is adjusted to be less than 0.5MPa, and the difference between the fracture pressure of the formation and the bottom hole pressure of the steam injection horizontal well (10) is adjusted to be more than 0.5 MPa.
7. The method for deep volume expansion oil recovery of a secondary reservoir branch SAGD reservoir as claimed in any one of claims 1 to 6, wherein the production horizontal well (20) needs to be temporarily blocked or shut down before the reservoirs around the steam injection horizontal well (10) and the production horizontal well (20) are expanded.
8. The reservoir secondary branch SAGD reservoir depth-extended oil recovery method of any one of claims 1-6, wherein the steam cycle is an isobaric injection steam cycle.
9. The deep-expansion oil production method of the SAGD reservoir stratum of the oil reservoir secondary branch according to claim 8, characterized in that before the steam circulation is performed on the steam injection horizontal well (10) and the production horizontal well (20), the steam injection horizontal well (10) and the production horizontal well (20) are respectively subjected to uniform isobaric circulation preheating, the steam injection pressure of the steam injection horizontal well (10) is the same as that of the bottom of the available oil reservoir, and the difference between the steam injection pressure and the formation pressure is less than or equal to 0.5 MPa.
10. The method for deep-expansion oil production of a secondary branch SAGD reservoir of an oil reservoir according to any one of claims 1-6, wherein when the primary branch (11) communicated with the secondary branch (12) and the production horizontal well (20) form an oil drainage channel, the viscosity of crude oil between the steam injection horizontal well (10) and the production horizontal well (20) is reduced to 1000 mPa-s, the steam injection pressure is greater than the minimum principal stress of the formation, the steam injection pressure is less than the fracture pressure of the formation by 0.5MPa, and the extraction-injection ratio of the available oil reservoir is between 0.80 and 0.85.
11. The deep capacity expansion oil production method of the oil reservoir secondary branch SAGD reservoir as claimed in any one of claims 1 to 6, characterized by stopping the capacity expansion of the reservoir around the steam injection horizontal well (10) and the reservoir around the production horizontal well (20) and continuously injecting water into the steam injection horizontal well (10) when the sum of the capacity expansion radius of the steam injection horizontal well (10) and the capacity expansion radius of the production horizontal well (20) is equal to the distance between the steam injection horizontal well (10) and the production horizontal well (20), and simmering the production horizontal well (20) at the same time when the water injection temperature is between 70 ℃ and 80 ℃.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115749707A (en) * | 2021-09-02 | 2023-03-07 | 中国石油天然气股份有限公司 | Method for exploiting super-heavy oil by using multi-branch horizontal well to assist SAGD (steam assisted gravity drainage) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101307689A (en) * | 2007-05-18 | 2008-11-19 | 中国海洋石油总公司 | Method for promoting thick oil oilfield oil well oil production |
| CA2877640A1 (en) * | 2014-01-13 | 2015-07-13 | John A. Stanecki | Oil recovery with fishbone wells and steam |
| CN204609851U (en) * | 2015-05-14 | 2015-09-02 | 兴和鹏能源技术(北京)股份有限公司 | Viscous crude SAGD dual horizontal well multiple-branching construction |
| CN105178931A (en) * | 2015-09-06 | 2015-12-23 | 中国石油天然气股份有限公司 | Method for increasing initial production speed of SAGD (Steam Assisted Gravity Drainage) |
| CN206722817U (en) * | 2017-08-21 | 2017-12-08 | 泰尔达能源科技（北京）有限公司 | The netted branch's well construction of viscous crude SAGD dual horizontal well two levels |
| CN108119113A (en) * | 2016-11-30 | 2018-06-05 | 中国石油天然气股份有限公司 | The method of heavy crude producing |
| CN110242266A (en) * | 2019-07-08 | 2019-09-17 | 新疆中凌工程技术有限公司 | A kind of horizontal well group of SAGD is temporarily stifled to be segmented dilatation reservoir reconstruction method |
| CN110284861A (en) * | 2019-05-20 | 2019-09-27 | 西南石油大学 | A method of intrinsic fracture heavy crude reservoir is exploited using Degradable temporary blocking agent auxiliary SAGD |
-
2019
- 2019-10-30 CN CN201911048007.XA patent/CN112746830A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101307689A (en) * | 2007-05-18 | 2008-11-19 | 中国海洋石油总公司 | Method for promoting thick oil oilfield oil well oil production |
| CA2877640A1 (en) * | 2014-01-13 | 2015-07-13 | John A. Stanecki | Oil recovery with fishbone wells and steam |
| CN204609851U (en) * | 2015-05-14 | 2015-09-02 | 兴和鹏能源技术(北京)股份有限公司 | Viscous crude SAGD dual horizontal well multiple-branching construction |
| CN105178931A (en) * | 2015-09-06 | 2015-12-23 | 中国石油天然气股份有限公司 | Method for increasing initial production speed of SAGD (Steam Assisted Gravity Drainage) |
| CN108119113A (en) * | 2016-11-30 | 2018-06-05 | 中国石油天然气股份有限公司 | The method of heavy crude producing |
| CN206722817U (en) * | 2017-08-21 | 2017-12-08 | 泰尔达能源科技（北京）有限公司 | The netted branch's well construction of viscous crude SAGD dual horizontal well two levels |
| CN110284861A (en) * | 2019-05-20 | 2019-09-27 | 西南石油大学 | A method of intrinsic fracture heavy crude reservoir is exploited using Degradable temporary blocking agent auxiliary SAGD |
| CN110242266A (en) * | 2019-07-08 | 2019-09-17 | 新疆中凌工程技术有限公司 | A kind of horizontal well group of SAGD is temporarily stifled to be segmented dilatation reservoir reconstruction method |
Non-Patent Citations (1)
| Title |
|---|
| 孙新革等: "陆相浅层超稠油SAGD提质增效技术体系研究", 《2018油气田勘探与开发国际会议（IFEDC 2018）论文集 工程科技I》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115749707A (en) * | 2021-09-02 | 2023-03-07 | 中国石油天然气股份有限公司 | Method for exploiting super-heavy oil by using multi-branch horizontal well to assist SAGD (steam assisted gravity drainage) |
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