CN117494395A - Fluid migration calculation method and system based on one-dimensional steady-state flow model - Google Patents
Fluid migration calculation method and system based on one-dimensional steady-state flow model Download PDFInfo
- Publication number
- CN117494395A CN117494395A CN202311344549.8A CN202311344549A CN117494395A CN 117494395 A CN117494395 A CN 117494395A CN 202311344549 A CN202311344549 A CN 202311344549A CN 117494395 A CN117494395 A CN 117494395A
- Authority
- CN
- China
- Prior art keywords
- fluid
- geothermal
- crust
- gas
- corrected
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000012530 fluid Substances 0.000 title claims abstract description 127
- 238000013508 migration Methods 0.000 title claims abstract description 81
- 230000005012 migration Effects 0.000 title claims abstract description 81
- 238000004364 calculation method Methods 0.000 title claims abstract description 33
- 239000007789 gas Substances 0.000 claims abstract description 116
- 239000011435 rock Substances 0.000 claims abstract description 71
- 238000000034 method Methods 0.000 claims abstract description 43
- 238000012937 correction Methods 0.000 claims abstract description 35
- 229910052734 helium Inorganic materials 0.000 claims abstract description 24
- 238000003915 air pollution Methods 0.000 claims abstract description 15
- 230000035699 permeability Effects 0.000 claims abstract description 12
- 230000015572 biosynthetic process Effects 0.000 claims description 25
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 238000009825 accumulation Methods 0.000 claims description 13
- 239000000203 mixture Substances 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- 238000004458 analytical method Methods 0.000 claims description 6
- 239000011261 inert gas Substances 0.000 claims description 4
- 230000000977 initiatory effect Effects 0.000 claims description 4
- 238000010276 construction Methods 0.000 claims description 3
- 238000012545 processing Methods 0.000 claims description 3
- 239000001307 helium Substances 0.000 abstract description 17
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 abstract description 17
- 239000011521 glass Substances 0.000 description 8
- 230000000694 effects Effects 0.000 description 5
- 230000000630 rising effect Effects 0.000 description 5
- 241001494479 Pecora Species 0.000 description 4
- 230000001174 ascending effect Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 238000007789 sealing Methods 0.000 description 4
- 241000828585 Gari Species 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 229920001296 polysiloxane Polymers 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000009189 diving Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- SWQJXJOGLNCZEY-BJUDXGSMSA-N helium-3 atom Chemical compound [3He] SWQJXJOGLNCZEY-BJUDXGSMSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2113/00—Details relating to the application field
- G06F2113/08—Fluids
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/08—Thermal analysis or thermal optimisation
Abstract
The invention discloses a fluid migration calculation method and a fluid migration calculation system based on a one-dimensional steady-state flow model, wherein the method comprises the following steps: collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas; considering the permeability and density of the crust rock, constructing a one-dimensional steady-state flow model; and estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas. According to the invention, the migration speed of the geothermic fluid curtain source helium is estimated by constructing a one-dimensional steady-state flow model by considering the permeability and density of the crust rock, so that the real migration condition of the curtain source fluid can be truly reflected. The fluid migration calculation method and the fluid migration calculation system based on the one-dimensional steady-state flow model can be widely applied to the technical field of fluid migration calculation.
Description
Technical Field
The invention relates to the technical field of fluid migration calculation, in particular to a fluid migration calculation method and system based on a one-dimensional steady-state flow model.
Background
Veil source fluid composition (e.g. He, CO 2 、N 2 ) Is an important means for understanding the quality and energy evolution between the earth surface and the interior, and plays an important role in volcanic eruption, earthquake monitoring and potential geothermal resource finding. In new generation volcanic areas such as the ocean midrib, volcanic arcs and hot spots of the diving band, magma is the carrier of the veil source helium rising to the surface for release, however, in continental areas lacking modern volcanic activity, the source of veil source helium and the release mechanism are still unclear. Quantitative assessment of the migration rate of veil source fluid and the time scale through the crust is critical to understanding formation time and activity, and also provides theoretical guidance for seismic monitoring and exploration of beneficial zones for geothermal resource development. At present, a method for quantitatively evaluating the migration rate of the mantle source fluid is the calculation of the average flow rate of the mantle source helium, which is applied to the calculation of the fluid rising rate of a san anderso fault system in california or the migration rate of a Peruvian plate released fluid, but the prior method does not consider the porosity of the crust, treats the fluid as a pipeline flow, and ignores the porosity of the crust, so that the estimated flow rate is 1-2 orders of magnitude lower than the actual flow rate, or ignores the difference between the rock density and the fluid density, namely ignores geological parameters, so that the prior method cannot truly reflect the actual migration condition of the mantle source fluid.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a fluid migration calculation method and a fluid migration calculation system based on a one-dimensional steady-state flow model, which can truly reflect the real migration condition of a curtain source fluid by constructing the one-dimensional steady-state flow model to estimate the migration speed of geothermal fluid curtain source helium by considering the permeability and the density of crust rock.
The first technical scheme adopted by the invention is as follows: the fluid migration calculation method based on the one-dimensional steady-state flow model comprises the following steps of:
collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas;
considering the permeability and density of the crust rock, constructing a one-dimensional steady-state flow model;
and estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas.
Further, the step of collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas specifically includes:
collecting and processing geothermal fluid by a drainage and gas collection method to obtain geothermal gas;
carrying out component analysis treatment on the geothermal gas by a mass spectrometer to obtain a component of the gas;
determining geothermal gas by measuring the composition of the gas by means of an inert gas mass spectrometer 3 He/ 4 Ratio of He and geothermal gas 4 He/ 20 A ratio of Ne;
based on the geothermal gas 4 He/ 20 Ne ratio to the geothermal gas 3 He/ 4 Air pollution correction treatment is carried out on the ratio of He to obtain corrected geothermal gas 3 He/ 4 Ratio of He.
Further, the step of the correction process specifically includes:
according to the atmosphere 4 He/ 20 Ne ratio and geothermal gas 4 He/ 20 The ratio of Ne determines a correction determination coefficient;
constructing a correction judgment coefficient threshold value;
and selecting the geothermal gas corresponding to the correction judgment coefficient larger than the threshold value of the correction judgment coefficient as corrected geothermal gas. Further, the expression of the correction process is specifically as follows:
R c /R a ＝[(R yp /R a )X-1]/(X-1)
X＝( 4 He/ 20 Ne) yp /( 4 He/ 20 Ne) air
in the above, R c Representing corrected 3 He/ 4 He ratio, R a Indicating the presence in the atmosphere 3 He/ 4 He ratio, ("He 4 He/ 20 Ne) air Indicating the presence in the atmosphere 4 He/ 20 Ne ratio, ( 4 He/ 20 Ne) yp Representing geothermal gases 4 He/ 20 Ne ratio, R yp Representing geothermal gases 3 He/ 4 He ratio, X represents a correction determination coefficient.
Further, the expression of the one-dimensional steady-state flow model is specifically as follows:
in the above, q represents the veil source fluid migration rate, t represents veil source fluid migration time, H c Indicating that the geothermal fluid passes through the thickness of the crust and P # 4 He) represents in earth crust rock 4 Rate of formation of He, ρ s Representing the density of the earth's crust rock,representing porosity [ 4 He] i,mantle Indicating that the veil is in the source fluid 4 Initial concentration of He, ρ f Representing the fluid density of the crust, R s Representing a geothermal gas sample 3 He/ 4 He ratio, R c Representing in earth's crust rock 3 He/ 4 He ratio, R i,mantle Indicating veil source fluid initiation 3 He/ 4 He ratio.
Further, the step of estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas specifically includes:
determination in crust rock 3 Rate of formation of He and 4 the rate of generation of He;
considering the density of the crust rock, the density of the crust fluid and the porosity of the crust rock, and combining the two 3 Rate of formation of He and 4 the generation rate of He, obtain crust of earthGenerated by rock 3 He (He) 4 The rate of accumulation of He in the earth's crust fluid;
determining He concentration in geothermal water and combining the corrected 3 He/ 4 He ratio, obtaining the mantle fluid 4 Initial concentration of He;
generated from the earth's crust rock 3 He (He) 4 Rate of accumulation of He in crust fluid and in said mantle fluid 4 Determining the migration time of the corrected geothermal gas according to the initial concentration of He;
and determining the migration rate of the corrected geothermal gas by combining the thickness of the crust rock.
Further, the acquisition of crust rock production 3 He (He) 4 The expression of the accumulation rate of He in the crust fluid is specifically as follows:
in the above formula, A is% 3,4 He) indicates formation of crust rock 3 He (He) 4 Accumulation rate of He in crust fluid, P # 3,4 He) represents in earth crust rock 3 Rate of formation of He and 4 rate of formation of He, ρ s Representing the density of the crust rock ρ f Representing the density of the fluid in the earth's crust,representing the porosity of the earth's crust rock.
Further, the obtaining of the mantle fluid 4 The expression for the initial concentration of He is specifically as follows:
[ 4 He] i,mantle ＝[ 4 He] s ×F( 4 He)
in the above [ 4 He] i,mantle Indicating in the mantle fluid 4 Initial concentration of He [ 4 He] s Represents the concentration of He and F in geothermal water 4 He) represents a veil source 4 He is a proportion thereof.
Further, the expression for determining the corrected geothermal gas migration time is specifically as follows:
in the above formula, t represents the corrected geothermal gas migration time.
The second technical scheme adopted by the invention is as follows: a fluid migration computing system based on a one-dimensional steady-state flow model, comprising:
the correction module is used for collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas;
the construction module is used for considering the permeability and density of the crust rock and constructing a one-dimensional steady-state flow model;
and the estimation module is used for estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas.
The method and the system have the beneficial effects that: according to the invention, through collecting geothermal gas and correcting, the air pollution possibly caused in the sampling and testing processes is avoided, the permeability and density of the crust rock are further considered, a one-dimensional steady-state flow model is constructed, the migration rule of fluid under natural conditions on the scale of a rock circle can be revealed, the migration speed and the migration time of geothermal fluid curtain source helium are estimated by constructing the one-dimensional steady-state flow model, the geochemical constraint of the rock circle structure is provided, the fluid ascending position of a hot field is determined, and the real migration condition of curtain source fluid can be truly reflected.
Drawings
FIG. 1 is a flow chart of steps of a fluid migration calculation method based on a one-dimensional steady-state flow model according to an embodiment of the present invention;
FIG. 2 is a block diagram of a fluid migration computing system based on a one-dimensional steady-state flow model in accordance with an embodiment of the present invention;
FIG. 3 is a schematic view of an apparatus for capturing geothermal gases by a water and gas drainage method according to an embodiment of the present invention;
FIG. 4 is a schematic diagram showing the calculation of fluid migration rate by the calculation method of the present invention compared to the existing calculation method at 10% porosity in accordance with an embodiment of the present invention;
FIG. 5 is a schematic diagram showing the calculation of fluid migration rate by the calculation method of the present invention compared to the existing calculation method at 1% porosity according to the embodiment of the present invention.
Detailed Description
The invention will now be described in further detail with reference to the drawings and to specific examples. The step numbers in the following embodiments are set for convenience of illustration only, and the order between the steps is not limited in any way, and the execution order of the steps in the embodiments may be adaptively adjusted according to the understanding of those skilled in the art.
Veil source fluid composition (e.g. He, CO 2 、N 2 ) Is an important means for understanding the quality and energy evolution between the earth's surface and interior, and plays an important role in volcanic eruption, seismic monitoring, and ascertaining potential geothermal resources. Hotsprings and geothermal wells release large volumes of hot fluid (e.g., he, CO 2 、N 2 ). Valance source helium contains more raw gas and is enriched in 3 He( 3 He/ 4 He=8±1Ra, wherein Ra is atmospheric 3 He/ 4 He ratio of 1.39X10 -6 ) The method comprises the steps of carrying out a first treatment on the surface of the Helium enrichment of shell source 4 He, from U% 235,238 U)、Th( 232 Th) is produced by alpha-radioactive decay, 3 He/ 4 he value is low (-0.02R) A ) Thus based on shell source helium and veil source helium 3 He/ 4 He ratio variability can effectively identify the area where the mantle gas is degassed. In new generation volcanic areas such as the ocean spine, volcanic arcs and hot spots of the dive zone, magma is the carrier of the valance source helium rising to the surface. However, in continental areas lacking modern volcanic activity, the source of valance-derived helium and the mechanism of release remain unclear. Previous studies have shown that in the absence of modern volcanic zones, potential factors that cause the release of veil source helium include: permeability enhancement of rock circle dimensions due to increased right-handed shear strain, and rock circle slip off, as a result of mantle melt intrusion into the extended structural zone of shallow crustThe fluid from the layer or slab activates helium in the continental rock mantle. Quantitative assessment of these processes, such as the migration rate of the veil source fluid and the time scale through the crust, is critical to understanding formation time and activity, and also provides theoretical guidance for seismic monitoring and exploration of beneficial areas for geothermal resource development. Hotsprings and geothermal wells release large volumes of hot fluid (e.g., he, CO 2 、N 2 ). At present, the method for quantitatively evaluating the migration rate of curtain source helium based on the gas collected by hot springs and geothermal wells mainly comprises the following 2 steps:
method 1: the average flow rate can be calculated from the following formula
The method is widely used to calculate the rate of fluid rise for the san andersoid fault system, california.
Method 2:
the method is applied to the migration rate of the Peruvian plate release fluid.
However, method 1 does not consider the porosity of the crust, treating the fluid as a pipe stream. While the upper limit of the porosity of the lower crust is 1% and the porosity of the upper crust is usually 10% according to the actual situation, therefore, neglecting the crust porosity results in an estimated flow rate 1-2 orders of magnitude lower than the actual flow rate. Whereas method 2 ignores the difference between rock density and fluid density, the average density of the crust is typically 2.8g cm -3 Fluid Density is taken to be 1.0g cm -3 It can be seen that the 2 methods ignore the geologic parameters to varying degrees and do not truly reflect the true migration conditions of the veil source fluid.
Based on this, referring to fig. 1, the present invention provides a fluid migration calculation method based on a one-dimensional steady-state flow model, the method comprising the steps of:
s1, collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas;
s11, collecting and processing geothermal fluid by a drainage and gas collection method to obtain geothermal gas;
in particular, geothermal gases (e.g., he, CO) are collected from hot springs or geothermal wells 2 ，N 2 ). The gas collection adopts a drainage and gas collection method, a funnel connected with a silicone tube is inversely immersed in a hot spring port, and a brine glass bottle (50 mL) is filled with geothermal water and immersed in the geothermal water. After the silicone tube and the funnel are washed for 30min by the local hot water and gas, the silicone tube is stretched into the glass bottle, and the gas is collected by adopting a gas collecting and draining method, as shown in figure 3, a small amount of the local hot water (sealing) is reserved in the bottle, the glass bottle is sealed by a rubber plug, and the glass bottle mouth is always immersed below the geothermal water surface in the whole process; and then taking out the glass bottle, sealing the glass bottle by using an aluminum cover, and filling the glass bottle into a 500ml polyethylene bottle filled with corresponding hot water to ensure no bubble residue, and sealing the glass bottle by using sealing glue so as to avoid atmospheric pollution in the transportation process.
S12, carrying out component analysis treatment on the geothermal gas through a mass spectrometer to obtain a component of the gas;
s13, determining the components of the gas through an inert gas mass spectrometer to determine geothermal gas 3 He/ 4 Ratio of He and geothermal gas 4 He/ 20 A ratio of Ne;
specifically, the gas composition and isotope analysis were carried out in a stable isotope composition analysis laboratory and a rare gas isotope analysis laboratory of the oil and gas center of the Lanzhou of the institute of geology and geophysics, academy of China, and the gas composition was measured by using a MAT 271 mass spectrometer with a detection limit of 0.0001% and a relative standard error<5％； 3 He/ 4 He (He) 4 He/ 20 Ne ratio was determined by a Noblesse inert gas mass spectrometer (Nu Instruments, UK).
S14, based on the geothermal gas 4 He/ 20 Ne ratio to the geothermal gas 3 He/ 4 And (3) correcting the ratio of He to obtain corrected geothermal gas.
S141、According to the atmosphere 4 He/ 20 Ne ratio and geothermal gas 4 He/ 20 The ratio of Ne determines a correction determination coefficient;
s142, constructing a correction judgment coefficient threshold value;
s143, selecting the geothermal gas corresponding to the correction judgment coefficient larger than the correction judgment coefficient threshold value as the corrected geothermal gas.
In particular, to eliminate air pollution that may be caused during sampling and testing, it is assumed that Ne in the sample is all from the atmosphere, based on the sample 4 He/ 20 Ne ratio to in sample 3 He/ 4 He ratio was corrected as follows:
R c /R a ＝[(R yp /R a )X-1]/(X-1)
X＝( 4 He/ 20 Ne) yp /( 4 He/ 20 Ne) air
in the above, R c Representing corrected 3 He/ 4 He ratio, R a Indicating the presence in the atmosphere 3 He/ 4 He ratio, ("He 4 He/ 20 Ne) air Indicating the presence in the atmosphere 4 He/ 20 Ne ratio, ( 4 He/ 20 Ne) yp Representing geothermal gases 4 He/ 20 Ne ratio, R yp Representing geothermal gases 3 He/ 4 He ratio, X represents a correction determination coefficient;
when the X value of the sample is more than 10, the effect of the helium isotope composition on the atmosphere helium is less, and when the X value is less than 10, the sample pollution is serious, and the data cannot be used.
S2, considering the permeability and density of the crust rock, and constructing a one-dimensional steady-state flow model;
specifically, the expression of the one-dimensional steady-state flow model is specifically as follows:
in the above, q represents valanceSource fluid migration rate, t represents veil source fluid migration time, H c Indicating that the geothermal fluid passes through the thickness of the crust and P # 4 He) represents in earth crust rock 4 Rate of formation of He, ρ s Representing the density of the earth's crust rock,representing porosity [ 4 He] i,mantle Indicating that the veil is in the source fluid 4 Initial concentration of He, ρ f Representing the fluid density of the crust, R s Representing a geothermal gas sample 3 He/ 4 He ratio, R c Representing in earth's crust rock 3 He/ 4 He ratio, R i,mantle Indicating veil source fluid initiation 3 He/ 4 He ratio.
S3, estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas.
S31, determining the position of the crust rock 3 Rate of formation of He and 4 the rate of generation of He;
specifically, the rock in the crust is calculated from the concentration (in ppm) of Li, U and Th in the crust rock 3 Rate of He formation (P 3 He)), and (b) is a compound of formula (i) 4 Rate of He formation (P 4 He) (in cm 3 STP g -1 rock year -1 Unit), its expression is:
P( 3 He)＝(2.64×10 -4 [U]+6.40×10 -5 [Th])×[Li]×10 -23 ×22414
P( 4 He)＝1.19634×10 -13 [U]+2.89665×10 -14 [Th]
in the above formula, P% 3 He) represents rock in the crust 3 The generation rate of He, P 4 He) represents rock in the crust 4 The rate of formation of He, li, U and Th represent the concentration of Li, U and Th in the crust rock.
S32, considering the density of the crust rock, the density of the crust fluid and the porosity of the crust rock, and combining the two materials 3 Rate of formation of He and 4 he (He)The generation rate is obtained to obtain the generation rate of the crust rock 3 He (He) 4 The rate of accumulation of He in the earth's crust fluid;
specifically, according to the crust density (ρ s ) Fluid density (ρ) f )，For porosity of rock in crust 3 He (He) 4 He formation Rate (cm) 3 STP g -1 rock year -1 ) Calculating crust generation 3 He (He) 4 Rate of accumulation of He in fluid (cm 3 STP g -1 H 2 O year -1 ) The expression is:
in the above formula, A is% 3,4 He) indicates formation of crust rock 3 He (He) 4 Accumulation rate of He in crust fluid, P # 3,4 He) represents in earth crust rock 3 Rate of formation of He and 4 rate of formation of He, ρ s Representing the density of the crust rock ρ f Representing the density of the fluid in the earth's crust,representing the porosity of the earth's crust rock.
S33, determining the He concentration in the geothermal water and combining the corrected He concentration 3 He/ 4 He ratio, obtaining the valance source fluid 4 Initial concentration of He;
specifically, the air correction is performed based on the measured He concentration in geothermal water and the sampled fluid 3 He/ 4 He ratio to calculate veil source fluid 4 Initial concentration of He ([ V) 4 He] i,mantle ，cm 3 g -1 H 2 O), the expression of which is:
[ 4 He] i,mdntle ＝[ 4 He] s ×F( 4 He)
in the above [ 4 He] i,mantle Indicating that the veil is in the source fluid 4 Initial concentration of He [ 4 He] s Represents the concentration of He and F in geothermal water 4 He) represents a veil source 4 He proportion, R s Representing a geothermal gas sample 3 He/ 4 He ratio, R c Representing in earth's crust rock 3 He/ 4 He ratio, R m Representing in the mantle 3 He/ 4 He ratio.
S34, generating according to the crust rock 3 He (He) 4 Accumulation rate of He in crust fluid and source fluid of the veil 4 Determining the migration time of the corrected geothermal gas according to the initial concentration of He;
specifically, the initial veil source fluid is caused by radioactivity in the crust during the process of rising from the veil to the ground 4 Generated by reaction of He with neutrons 3 He further dilutes, thus the veil source fluid reaching the surface 3 He/ 4 He ratio is related to migration time and can be expressed by the following equation:
R s ＝(R i,mantle ×[ 4 He] i,mantle +A( 3 He)×t)/([ 4 He] i,mantle +A( 4 He)×t)
in the above, R s Indicating corrected air pollution of the sample 3 He/ 4 He value, t represents fluid migration time, R i,mantle Sum [ 4 He] i,mantle Respectively represent curtain source fluid initiation 3 He/ 4 He ratio (8+ -1 Ra) 4 He concentration (cm) 3 g -1 H 2 O)，A( 3 He) and A% 4 He) indicates the generation of crust 3 He (He) 4 The rate of accumulation of He in the fluid;
the migration time of the veil source fluid can be derived as:
in the above formula, t represents the corrected geothermal gas migration time.
S35, determining the migration rate of the corrected geothermal gas by combining the crust thickness.
Referring to fig. 4 and 5, it can be seen from a comparison of the three methods according to the prior art methods 1 and 2 that, in comparison with the present invention and method 2, method 1 does not consider the porosity of the crust of the earth and treats the fluid as a pipe stream. While the upper limit of the porosity of the lower crust is 1% and the porosity of the upper crust is usually 10% according to the actual situation, therefore, neglecting the crust porosity results in an estimated flow rate 1-2 orders of magnitude lower than the actual flow rate. Whereas method 2 ignores the difference between rock density and fluid density compared to the present study and method 1, the average density of the crust is typically 2.8g cm -3 The solid density is 1.0g cm -3 Therefore, the formula for calculating the migration rate and time of the fluid in the rock circle scale based on the one-dimensional steady-state flow model fully considers the permeability of the crust and the difference of the densities of the rock and the fluid, and can reflect the average rising speed of the curtain source fluid under the natural condition more truly.
Further, experiments of the invention were conducted using Qinghai-Tibet plateau as a detection area;
collecting geothermal fluid of sheep eight well and Garisin of Adam Gu Lou cutting line of Qinghai-Tibet plateau in the field, and analyzing helium content and 3 He/ 4 he ratio (R) m ) And air pollution correction (R c ) As shown in tables 1 and 2, porosityTaking down the upper limit of 1% of the crust, wherein according to the U content of 1.3ppm, the Th content of 5.6ppm and the Th/U content of 4.3 in the crust, the crust 4 Average He yield P [ ] 4 He) of 3.17X10 -13 cm 3 STP g -1 rock year -1 Crust density (ρ) s ) 2.8g cm -3 Fluid density (ρ) f ) 1g cm -3 The method comprises the steps of carrying out a first treatment on the surface of the Crust thickness (H) c ) According to geophysical data acquisition, the sheep's eighth well is 75.2km and Gari is 74.3km, according to the acquisition of the mantle source fluid 4 Calculation formula of initial concentration of He to obtain valance source 4 Initial content of He [ 4 He] i,mantle The method comprises the steps of carrying out a first treatment on the surface of the Substituting the parameters into a calculation formula for determining the corrected geothermal gas migration time and a calculation formula for a one-dimensional steady-state flow model can obtain the geothermal fluid eight-well with the average migration time of 20.2ka, the ascending migration rate of 3720 mm/year, the average migration time of Galois of 37.8ka and the ascending migration rate of 1960 mm/year, and the geothermal resource exploitation condition is more favorable compared with Galois of the eight-well with a better fluid ascending channel. At the same time, it also shows that based on Qinghai-Tibet plateau 3 He/ 4 The deep dynamics evolution state revealed by He ratio is between Qinghai-Tibet Gao Yuanyan Dan Xue%>8 Ma) and the rock ring structural state revealed by the geophysical prospecting method.
TABLE 1 Qinghai-Tibet plateau sheep eight well and Gari poor geothermal gas 3 He/ 4 He value correction
TABLE 2 calculation of the rise rate and migration time of Qinghai-Tibet plateau sheep eight well and Gari poor geothermal fluid
Referring to fig. 2, a fluid migration computing system based on a one-dimensional steady-state flow model, comprising:
the correction module is used for collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas;
the construction module is used for considering the permeability and density of the crust rock and constructing a one-dimensional steady-state flow model;
and the estimation module is used for estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas.
The content in the method embodiment is applicable to the system embodiment, the functions specifically realized by the system embodiment are the same as those of the method embodiment, and the achieved beneficial effects are the same as those of the method embodiment.
While the preferred embodiment of the present invention has been described in detail, the invention is not limited to the embodiment, and various equivalent modifications and substitutions can be made by those skilled in the art without departing from the spirit of the invention, and these modifications and substitutions are intended to be included in the scope of the present invention as defined in the appended claims.
Claims (10)
1. The fluid migration calculation method based on the one-dimensional steady-state flow model is characterized by comprising the following steps of:
collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas;
considering the permeability and density of the crust rock, constructing a one-dimensional steady-state flow model;
and estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas.
2. The fluid migration calculation method based on the one-dimensional steady-state flow model of claim 1, wherein the corrected geothermal gas represents corrected geothermal gas 3 He/ 4 He ratio, the geothermal fluid includes geothermal gas and geothermal water, the step of collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas, which specifically includes:
collecting and processing geothermal fluid by a drainage and gas collection method to obtain geothermal gas;
carrying out component analysis treatment on the geothermal gas by a mass spectrometer to obtain a component of the gas;
determining geothermal gas by measuring the composition of the gas by means of an inert gas mass spectrometer 3 He/ 4 Ratio of He and geothermal gas 4 He/ 20 A ratio of Ne;
based on the geothermal gas 4 He/ 20 Ne ratio to the geothermal gas 3 He/ 4 And (3) carrying out air pollution correction treatment on the ratio of He to obtain corrected geothermal gas.
3. The fluid migration calculation method based on the one-dimensional steady-state flow model according to claim 2, wherein the step of correcting specifically includes:
according to the atmosphere 4 He/ 20 Ne ratio and geothermal gas 4 He/ 20 The ratio of Ne determines a correction determination coefficient;
constructing a correction judgment coefficient threshold value;
and selecting the geothermal gas corresponding to the correction judgment coefficient larger than the threshold value of the correction judgment coefficient as corrected geothermal gas.
4. The fluid migration calculation method based on the one-dimensional steady-state flow model according to claim 2, wherein the expression of the correction process is specifically as follows:
R c /R a ＝[(R yp /R a )X-1]/(X-1)
X＝( 4 He/ 20 Ne) yp /( 4 He/ 20 Ne) air
in the above, R c Representing corrected 3 He/ 4 He ratio, R a Indicating the presence in the atmosphere 3 He/ 4 He ratio, ("He 4 He/ 20 Ne) air Indicating the presence in the atmosphere 4 He/ 20 Ne ratio, ( 4 He/ 20 Ne) yp Representing geothermal gases 4 He/ 20 Ne ratio, R yp Representing geothermal gases 3 He/ 4 He ratio, X represents a correction determination coefficient.
5. The fluid migration calculation method based on the one-dimensional steady-state flow model according to claim 1, wherein the expression of the one-dimensional steady-state flow model is specifically as follows:
in the above, q represents the veil source fluid migration rate, t represents veil source fluid migration time, H c Indicating that the geothermal fluid passes through the thickness of the crust and P # 4 He) represents in earth crust rock 4 Rate of formation of He, ρ s Representing the density of the earth's crust rock,representing porosity [ 4 He] i，mantle Indicating that the veil is in the source fluid 4 Initial concentration of He, ρ f Representing the fluid density of the crust, R s Representing a geothermal gas sample 3 He/ 4 He ratio, R c Representing in earth's crust rock 3 He/ 4 He ratio, R i，mantle Indicating veil source fluid initiation 3 He/ 4 He ratio.
6. The fluid migration calculation method based on the one-dimensional steady-state flow model according to claim 5, wherein the step of estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas specifically comprises:
determination in crust rock 3 Rate of formation of He and 4 the rate of generation of He;
considering the density of the crust rock, the density of the crust fluid and the porosity of the crust rock, and combining the two 3 Rate of formation of He and 4 the generation rate of He, the generation rate of crust rock is obtained 3 He (He) 4 The rate of accumulation of He in the earth's crust fluid;
determining He concentration in geothermal water and combining the corrected 3 He/ 4 He ratio, obtaining the mantle fluid 4 Initial concentration of He;
generated from the earth's crust rock 3 He (He) 4 Rate of accumulation of He in crust fluid and in said mantle fluid 4 Determining the migration time of the corrected geothermal gas according to the initial concentration of He;
and determining the migration rate of the corrected geothermal gas by combining the thickness of the crust rock.
7. The method of calculating fluid migration based on one-dimensional steady-state flow model of claim 6, wherein the obtaining of formation of crust rock 3 He (He) 4 The expression of the accumulation rate of He in the crust fluid is specifically as follows:
in the above formula, A is% 3，4 He) indicates formation of crust rock 3 He (He) 4 Accumulation rate of He in crust fluid, P # 3，4 He) represents in earth crust rock 3 Rate of formation of He and 4 rate of formation of He, ρ s Representing the density of the crust rock ρ f Representing the density of the fluid in the earth's crust,representing the porosity of the earth's crust rock.
8. The method of calculating fluid migration based on one-dimensional steady-state flow model of claim 6, wherein the obtaining mantle fluid 4 The expression for the initial concentration of He is specifically as follows:
[ 4 He] i，mantle ＝[ 4 He] s ×F( 4 He)
in the above [ 4 He] i，mantle Indicating in the mantle fluid 4 Initial concentration of He [ 4 He] s Represents the concentration of He and F in geothermal water 4 He) represents a veil source 4 He is a proportion thereof.
9. The fluid migration calculation method based on the one-dimensional steady-state flow model according to claim 6, wherein the expression for determining the migration time of the corrected geothermal gas is specifically as follows:
in the above formula, t represents the corrected geothermal gas migration time.
10. A fluid migration computing system based on a one-dimensional steady-state flow model, comprising the following modules:
the correction module is used for collecting geothermal gas and performing air pollution correction treatment to obtain corrected geothermal gas;
the construction module is used for considering the permeability and density of the crust rock and constructing a one-dimensional steady-state flow model;
and the estimation module is used for estimating the corrected geothermal gas according to the one-dimensional steady-state flow model to obtain the migration rate of the corrected geothermal gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311344549.8A CN117494395A (en) | 2023-10-17 | 2023-10-17 | Fluid migration calculation method and system based on one-dimensional steady-state flow model |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311344549.8A CN117494395A (en) | 2023-10-17 | 2023-10-17 | Fluid migration calculation method and system based on one-dimensional steady-state flow model |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117494395A true CN117494395A (en) | 2024-02-02 |
Family
ID=89671665
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311344549.8A Pending CN117494395A (en) | 2023-10-17 | 2023-10-17 | Fluid migration calculation method and system based on one-dimensional steady-state flow model |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117494395A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7210342B1 (en) * | 2001-06-02 | 2007-05-01 | Fluid Inclusion Technologies, Inc. | Method and apparatus for determining gas content of subsurface fluids for oil and gas exploration |
| US20160146961A1 (en) * | 2014-11-25 | 2016-05-26 | Cgg Services Sa | Method for elastic model perturbation estimation from reverse time migration |
| CN114384228A (en) * | 2021-11-29 | 2022-04-22 | 中铁第一勘察设计院集团有限公司 | Method for surveying harmful gas of non-coal formation tunnel in geological complex region |
| CN116430474A (en) * | 2023-03-02 | 2023-07-14 | 中国煤炭地质总局勘查研究总院 | Geothermal resource reserve calculation method, geothermal resource reserve calculation system and electronic equipment |
-
2023
- 2023-10-17 CN CN202311344549.8A patent/CN117494395A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7210342B1 (en) * | 2001-06-02 | 2007-05-01 | Fluid Inclusion Technologies, Inc. | Method and apparatus for determining gas content of subsurface fluids for oil and gas exploration |
| US20160146961A1 (en) * | 2014-11-25 | 2016-05-26 | Cgg Services Sa | Method for elastic model perturbation estimation from reverse time migration |
| CN114384228A (en) * | 2021-11-29 | 2022-04-22 | 中铁第一勘察设计院集团有限公司 | Method for surveying harmful gas of non-coal formation tunnel in geological complex region |
| CN116430474A (en) * | 2023-03-02 | 2023-07-14 | 中国煤炭地质总局勘查研究总院 | Geothermal resource reserve calculation method, geothermal resource reserve calculation system and electronic equipment |
Non-Patent Citations (3)
| Title |
|---|
| YINLEI HAO等: "Degassing of Mantle‐Derived Helium From Hot Springs Along the India‐Asia Continental Collision Settings: Origins, Migration Velocity and Flux", 《GEOCHEMISTRY》, 13 January 2024 (2024-01-13) * |
| 汪洋: "利用地下流体氦同位素比值估算 大陆壳幔热流比例", 《地球物理学报》, 30 November 2000 (2000-11-30) * |
| 赵平, MACK KENNEDY, 多吉, 谢鄂军, 杜少平, DAVID SHUSTER, 金建: "西藏羊八井热田地热流体成因及演化的惰性气体制约", 岩石学报, no. 03, 30 August 2001 (2001-08-30), pages 497 - 503 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Marine | The use of naturally occurring helium to estimate groundwater velocities for studies of geologic storage of radioactive waste | |
| Fu et al. | Spatial and temporal anomalies of soil gas in northern Taiwan and its tectonic and seismic implications | |
| Sano et al. | The analysis and interpretation of noble gases in modern hydrothermal systems | |
| Jones et al. | Terminal Ordovician carbon isotope stratigraphy and glacioeustatic sea-level change across Anticosti Island (Québec, Canada) | |
| Sugisaki | Changing He/Ar and N2/Ar ratios of fault air may be earthquake precursors | |
| Dukat et al. | Non-steady-state 210Pb flux and the use of 228Ra/226Ra as a geochronometer on the Amazon continental shelf | |
| CN113759424B (en) | Karst reservoir filling analysis method and system based on spectral decomposition and machine learning | |
| Brown et al. | The seismic structure of island arc crust | |
| Werner et al. | Volatile emissions and gas geochemistry of Hot Spring Basin, Yellowstone National Park, USA | |
| Rowan et al. | Radon-222 content of natural gas samples from Upper and Middle Devonian sandstone and shale reservoirs in Pennsylvania—preliminary data | |
| Zhang et al. | Flux and genesis of CO2 degassing from volcanic-geothermal fields of Gulu-Yadong rift in the Lhasa terrane, South Tibet: Constraints on characteristics of deep carbon cycle in the India-Asia continent subduction zone | |
| Rissmann et al. | Surface heat flow and CO2 emissions within the Ohaaki hydrothermal field, Taupo Volcanic Zone, New Zealand | |
| Brown | Origin of helium and nitrogen in the Panhandle–Hugoton field of Texas, Oklahoma, and Kansas, United States | |
| Tomonaga et al. | Spatial distribution and flux of terrigenic He dissolved in the sediment pore water of Lake Van (Turkey) | |
| Huang et al. | Spatial distribution and geochemistry of the nearshore gas seepages and their implications to natural gas migration in the Yinggehai Basin, offshore South China Sea | |
| Hernández et al. | Radon and helium in soil gases at Cañadas caldera, Tenerife, Canary Islands, Spain | |
| Han et al. | Well log evaluation of shale gas reservoirs and preservation conditions of Lower Cambrian shale succession in Cengong Block of southeast Sichuan basin, south China | |
| CN116047624A (en) | Helium resource amount evaluation method | |
| Hathway et al. | Revised stratigraphy, regional correlations and new bentonite radiometric ages for the Albian Loon River Formation, Fort St. John Group, northwestern Alberta | |
| Donda et al. | The origin of gas seeps in the Northern Adriatic Sea | |
| CN117494395A (en) | Fluid migration calculation method and system based on one-dimensional steady-state flow model | |
| Barnes et al. | Helium flux through marine sediments of the northeast Pacific Ocean | |
| Bertrami et al. | Soil gases in geothermal prospecting: two case histories (Sabatini Volcanoes and Alban Hills, Latium, Central Italy) | |
| CN116299764A (en) | Geochemical tracing method for hidden sandstone type uranium ores | |
| Loreto et al. | Mantle degassing on a near shore volcano, SE Tyrrhenian Sea |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |