CN113588489A - Shale gas capacity method isothermal adsorption experiment test limit determination method - Google Patents
Shale gas capacity method isothermal adsorption experiment test limit determination method Download PDFInfo
- Publication number
- CN113588489A CN113588489A CN202110938364.4A CN202110938364A CN113588489A CN 113588489 A CN113588489 A CN 113588489A CN 202110938364 A CN202110938364 A CN 202110938364A CN 113588489 A CN113588489 A CN 113588489A
- Authority
- CN
- China
- Prior art keywords
- gas
- sample
- adsorption
- tank
- limit
- 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.)
- Granted
Links
- 238000001179 sorption measurement Methods 0.000 title claims abstract description 153
- 238000000034 method Methods 0.000 title claims abstract description 68
- 238000002474 experimental method Methods 0.000 title claims abstract description 42
- 238000012360 testing method Methods 0.000 title claims abstract description 21
- 239000007789 gas Substances 0.000 claims description 163
- 238000004364 calculation method Methods 0.000 claims description 12
- 238000007906 compression Methods 0.000 claims description 12
- 230000000274 adsorptive effect Effects 0.000 claims description 9
- 230000006835 compression Effects 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 238000009924 canning Methods 0.000 claims description 3
- 239000003245 coal Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 1
- 201000004569 Blindness Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N7/00—Analysing materials by measuring the pressure or volume of a gas or vapour
- G01N7/02—Analysing materials by measuring the pressure or volume of a gas or vapour by absorption, adsorption, or combustion of components and measurement of the change in pressure or volume of the remainder
- G01N7/04—Analysing materials by measuring the pressure or volume of a gas or vapour by absorption, adsorption, or combustion of components and measurement of the change in pressure or volume of the remainder by absorption or adsorption alone
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N2015/0866—Sorption
Landscapes
- Chemical & Material Sciences (AREA)
- Biochemistry (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Pathology (AREA)
- General Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Immunology (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Sampling And Sample Adjustment (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
The invention provides a method for determining a test limit of an isothermal adsorption experiment by a shale gas capacity method, which comprises the following steps: determining the free space volume of the sample canister containing the sample; measuring the gas adsorption capacity of the sample according to the free space volume of the sample tank; the gas adsorption quantity and the sample amount of a known sample are reversely deduced to obtain the gas pressure change in the balanced final state sample tank caused by adsorption, and the precision limit of the pressure sensor is determined according to the gas pressure change value in the balanced final state sample tank caused by adsorption; determination of minimum sample usage limit: the known gas adsorption capacity and the accuracy limit of the pressure sensor are inversely extrapolated to obtain a minimum sample usage limit. The method can determine the minimum precision of the used pressure sensor when the sample usage is determined, and can also determine the minimum sample usage limit required in the device experiment under the condition that the experimental device is determined so as to guide the isothermal adsorption experiment of the shale gas capacity method.
Description
Technical Field
The invention belongs to the technical field of petroleum engineering, and relates to a shale gas capacity method isothermal adsorption experiment test limit determination method.
Background
Shale gas is a hotspot for unconventional natural gas development in China, the isothermal adsorption experiment of shale gas and the acquisition of adsorption characteristic parameters are important links and means for shale gas resource evaluation and production prediction, and the evaluation and prediction results are greatly influenced by the non-normative experimental method, the variety of errors and the uncontrollable error of the experimental method.
The isothermal adsorption experiment testing technology in coal bed gas research is mature, the isothermal adsorption experiment device and method for shale gas are developed from the experimental device and method for coal bed gas, but the adsorption amount of shale to gas is less than 1/10 of coal, so the adsorption experiment testing difficulty is high, the experimental method is controversial, and the results made by laboratories are different. Summary the shale gas isothermal adsorption experimental method currently needs attention to the following outstanding problems: the principles of the volumetric method and the gravimetric method, the sample dosage, the pretreatment process, the judgment of the balance condition and the data processing method are different, and the application conditions and the test boundaries of the volumetric method and the gravimetric method isothermal adsorption experiment need to be determined so as to reduce the blindness of the experiment test and even the invalidity.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for determining the testing limit of the isothermal adsorption experiment of the shale gas capacity method, which can determine the minimum precision of the used pressure sensor when the sample usage is determined, and can also determine the minimum sample usage limit required in the experiment of the device under the condition that the experimental device is determined, so as to guide the isothermal adsorption experiment of the shale gas capacity method.
The invention is realized by the following technical scheme:
a method for determining testing limits of isothermal adsorption experiments by a shale gas capacity method is based on an isothermal adsorption experiment device by the shale gas capacity method, the isothermal adsorption experiment device by the shale gas capacity method comprises a reference tank and a sample tank, and a gas flow and vacuumizing interface valve is connected to a gas inlet pipeline of the reference tank; the air outlet of the reference tank is connected with the air inlet of the sample tank; a valve is arranged on a connecting pipeline of the reference tank and the sample tank; the gas temperature sensor is used for detecting the gas temperature in the reference tank and the sample tank;
the method comprises the following steps:
determining the free space volume of the sample canister containing the sample;
measuring the gas adsorption capacity of the sample according to the free space volume of the sample tank;
determination of the accuracy limit of the second pressure sensor: the gas adsorption quantity and the sample amount of the known sample are reversely deduced to obtain the gas pressure change in the balanced final state sample tank caused by adsorption, and the precision limit of the second pressure sensor is determined according to the gas pressure change value in the balanced final state sample tank caused by adsorption;
determination of minimum sample usage limit: the known gas adsorption capacity and the accuracy limit of the second pressure sensor are inversely extrapolated to obtain a minimum sample usage limit.
Preferably, the accuracy limit of the second pressure sensor is specifically determined as follows:
calculating the gas pressure p in the sample tank in the equilibrium final state according to the gas adsorption amount and the sample amount of the samplesv2；
Then the gas pressure p in the final state sample tank is balanced when no adsorption occurs and is obtained by calculating the volume of the free space of the sample tanksv2Is recorded as p'sv2；
psv2And p'sv2Subtracting the two to obtain the gas pressure change delta p in the equilibrium final state sample tank caused by adsorptionsv2；
According to Δ psv2Determining a limit of accuracy of the second pressure sensor, wherein the limit of accuracy of the second pressure sensor is to satisfy more than Δ psv2A minimum value.
Preferably, the determination of the free space volume of the sample tank is in particular: opening a flowing gas and vacuumizing interface valve, filling non-adsorptive gas into a reference tank, closing the flowing gas and vacuumizing interface valve, opening a valve arranged on a connecting pipeline between the reference tank and a sample tank, allowing the non-adsorptive gas to enter the sample tank, recording the gas pressure in the reference tank and the sample tank in the initial state and the adsorption balance final state, closing the valve arranged on the connecting pipeline between the reference tank and the sample tank, and repeating the process until the highest experimental pressure is reached; and obtaining the volume of the free space of the sample tank according to the gas pressure, the compression factor and the gas temperature in the reference tank and the sample tank in the initial state and the adsorption balance final state.
Further, the calculation formula of the free space volume of the sample tank is shown in formula (1):
in the formula, VsvfIs the free space volume, cm, of the sample after filling3；pcv1And psv1The gas pressure in the reference tank and the gas pressure in the sample tank are respectively MPa in the initial state; p is a radical ofsv2The gas pressure in the reference tank and the sample tank is MPa after the reference tank and the sample tank are communicated when the adsorption balance is in the final state; zcv1And Zsv1 eachCompression factors, Z, of gases in reference and sample tanks in the initial statesv2The compression factors of the gas in the reference tank and the gas in the sample tank are dimensionless when the adsorption balance is in a final state; r is gas constant 8.341X 10-6，MPa·m3·mol-1·K-1；T1、T2Water bath temperature at initial state and adsorption equilibrium final state, K; vcvFor reference to the volume of the free space of the tank, cm3。
Further, the specific measurement of the gas adsorption amount of the sample is as follows: opening a flowing gas and vacuumizing interface valve, filling adsorptive gas into a reference tank, closing the flowing gas and vacuumizing interface valve, opening a valve arranged on a connecting pipeline between the reference tank and a sample tank, allowing the adsorptive gas to enter the sample tank, recording the gas pressure in the reference tank and the sample tank in the initial state and the final state of adsorption balance, closing the valve arranged on the connecting pipeline between the reference tank and the sample tank, and repeating the processes until the highest experimental pressure is reached; and obtaining the gas adsorption quantity according to the gas pressure and the compression factor in the reference tank and the sample tank, the gas temperature, the free space volume of the sample tank and the mass of the sample in the sample tank in the initial state and the adsorption balance final state.
Further, the calculation formula of the gas adsorption amount in the first balancing is as follows:
in the formula, msIs the mass of the sample, kg; vgadsVolume per unit mass of gas adsorbed in the sample in the standard condition, cm, during which this adsorption reaches equilibrium3/g；VmGas molar volume, 22.4L/mol; the amount of gas adsorbed after multiple adsorbtions is calculated by the following formula (3):
in the formula, ngadsIs the amount of species of gas adsorbed by the sample, mol; vgads|iThe volume of gas adsorbed per unit mass of sample after the ith adsorption equilibrium under standard conditions, referred to as gas adsorption capacity, 10-3m3/kg。
Further, the accuracy limit of the second pressure sensor is specifically determined as follows:
firstly, the gas adsorption quantity V in a single adsorption process is knowngadsThe gas pressure p in the sample tank at the equilibrium final state is obtained from the formula (2)sv2Comprises the following steps:
in the formula (4), VgadsWhen the adsorption does not occur, the gas pressure p in the final state sample tank is obtainedsv2Is recorded as p'sv2：
Subtracting the two to obtain the gas pressure change delta p in the equilibrium final state sample tank caused by adsorptionsv2Comprises the following steps:
according to Δ psv2Determining a limit of accuracy of the second pressure sensor, wherein the limit of accuracy of the second pressure sensor is to satisfy more than Δ psv2A minimum value.
Further, the known gas adsorption amount and the accuracy limit of the second pressure sensor inversely deduct the sample usage limit, specifically:
knowing the gas adsorption V in a single adsorption processgadsThe gas pressure p in the sample tank at the equilibrium final state is obtained from the formula (2)sv2Comprises the following steps:
in the formula (4), VgadsWhen the adsorption does not occur, the gas pressure p in the final state sample tank is obtainedsv2Is recorded as p'sv2:
When V isgadsKnown, it is obtained from formula (2):
equilibrium end state sample tank gas pressure change Δ p due to adsorptionsv2＝p’sv2-psv2To obtain psv2＝p’sv2-Δpsv2Substituting formula (7) to obtain:
relationship between free space volume and sample mass after sample canning:
Vsvf＝Vsv-Vs＝Vsv-ms/ρs (9)
substituting formula (9) for formula (5) yields:
substituting equations (10) and (9) for equation (8) to obtain a model for back-estimating the amount of sample used given the amount of gas adsorbed and the accuracy limit of the second pressure sensor, equation (11):
in formula (11), Δ psv2The value is the precision limit of the second pressure sensor
In the case of (2), equation (11) is solved, and the minimum value obtained is the sample dose limit.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention establishes a test limit model of isothermal adsorption experiment of shale gas capacity method according to free space volume and adsorption capacity, and can determine the minimum precision of the pressure sensor when the sample usage is fixed, and can determine the minimum sample usage limit required in the experiment of the device under the condition that the experimental device is fixed, so as to guide the isothermal adsorption experiment of shale gas capacity method.
Drawings
FIG. 1 is a schematic diagram of an isothermal adsorption experimental device by a shale gas volumetric method;
description of the drawings: 1-air flow and vacuum pumping interface valve, 2-sampling interface valve, 3-reference tank, 4, 8-pressure sensor, 5-pneumatic valve, 6-manual valve, 7-temperature sensor, 9-lifting bracket, 10-thermostatic water bath device, 11-sample tank, 12, 13, 14-valve.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
The method for determining the testing limit of the isothermal adsorption experiment of the shale gas capacity method is realized based on the isothermal adsorption experiment device of the shale gas capacity method shown in figure 1, the device comprises a reference tank 3 and a sample tank 11, and a gas flow and vacuumizing interface valve 1 and a sampling interface valve 2 are connected on a gas inlet pipeline of the reference tank 3; the gas outlet of the reference tank 3 is connected with the gas inlet of the sample tank 11, a pneumatic valve 5 and a manual valve are arranged on a connecting pipeline between the reference tank 3 and the sample tank 11, a first pressure sensor 4 is arranged on a pipeline between the pneumatic valve 5 and the reference tank 3, a second pressure sensor 8 and a temperature sensor 7 are arranged on a pipeline between the manual valve 6 and the sample tank 11, and valves 12, 13 and 14 are arranged on a gas outlet pipeline of the sample tank 11. The whole experimental apparatus is placed on a lifting bracket 9 and is placed in a constant temperature water bath device 10.
The technical scheme adopted by the invention is as follows:
(1) isothermal adsorption experimental method of shale gas capacity method
Measurement of free space volume after sample canning
In the volumetric isothermal adsorption experiment, the free space volume measurement method comprises the following steps: filling helium into the reference tank 3, opening the valve 5, introducing gas into the sample tank 11, recording the gas pressure in the reference tank 3 and the sample tank 11 in the initial state and the adsorption equilibrium final state, closing the valve 5 to separate the two tanks, and repeating the above processes until the highest experimental pressure is reached. The free space volume calculation formula is shown as follows:
in the formula, VsvfIs as followsVolume in free space, cm, after filling of the sample in a can3；VsIs the volume of the sample, cm3；pcv1、psv1The gas pressure in the reference tank and the sample tank is MPa in the initial state; p is a radical ofsv2The gas pressure in the reference tank and the sample tank is MPa after the reference tank and the sample tank are communicated when the adsorption balance is in the final state; zcv1、Zsv1Compression factors, Z, of gases in reference and sample tanks in the initial statesv2The compression factors of the gas in the reference tank and the gas in the sample tank are dimensionless when the adsorption balance is in a final state; r is gas constant 8.341X 10-6，MPa·m3·mol-1·K-1；T1、T2Water bath temperature at initial state and adsorption equilibrium final state, K; vcv、VsvVolume in free space, cm, of the reference and sample tanks, respectively3。
Measurement of gas adsorption quantity
The amount of gas adsorbed is determined in the same manner as for the free space volume, except that the adsorptive gas is used. The calculation formula of the adsorption amount in the first-time equilibrium is as follows:
in the formula, msIs the mass of the sample, kg; vgadsVolume per unit mass of gas adsorbed in the sample in the standard condition, cm, during which this adsorption reaches equilibrium3/g；VmIs the gas molar volume, 22.4L/mol. Note that the adsorption amount in the isothermal adsorption curve is the cumulative adsorption amount, not the adsorption amount at single equilibrium, and the corresponding adsorption amount is calculated by the equation:
in the formula, ngadsIs the amount of species of gas adsorbed by the sample, mol; vgads|iThe volume of gas adsorbed by the unit mass sample after the ith adsorption equilibrium under standard conditions, referred to as adsorption capacity, 10-3m3/kg。
(2) Known adsorption quantity and sample quantity back-pushing pressure sensor precision limit
The known method for solving the pressure change caused by adsorption by the adsorption quantity and the sample quantity comprises two steps: first of all, the adsorption quantity V in a single adsorption process is knowngadsThe pressure p in the sample tank at the equilibrium final state is obtained from the formulasv2Comprises the following steps:
note that in the formula Zsv2Is psv2So that iterative calculations are required.
In the formula (4), VgadsWhen the adsorption does not occur, the equilibrium final state sample tank internal pressure p can be obtained as 0sv2Is denoted herein as p'sv2：
In the formula Zsv2Is p'sv2The function of (2) also needs to be calculated iteratively.
Subtracting the two to obtain the pressure change delta p of the equilibrium final state sample tank caused by adsorptionsv2Comprises the following steps:
when the adsorption amount is zero, the formula is equal to the formula, Δ psv2＝0。
The adsorption-induced pressure change value actually corresponds to the precision of the pressure sensor of the sample tank, namely, the adsorption quantity can be measured through a volumetric adsorption experiment only when the precision of the pressure sensor is greater than the minimum value of the adsorption-induced pressure change, otherwise, the method and the device are not applicable. Thereby, the pressure change Δ p of the equilibrium final state sample tank due to adsorptionsv2The accuracy limit of the pressure sensor can be obtained.
(3) Sample usage bound is inferred by known adsorption and pressure sensor accuracy bound
Similarly, since the adsorption amount is defined as the volume of the gas adsorbed by a unit mass of the sample under a standard condition, the sample usage limit can be reversely obtained by knowing the adsorption amount and the pressure change value caused by adsorption of the sample, namely knowing the adsorption amount and the precision limit of the pressure sensor. The amount of sample used is controlled in two ways: firstly, the more samples are in the experiment, the more adsorbed gas is, the larger the pressure drop caused by adsorption is, and the easier the pressure drop is to be measured by a pressure sensor; secondly, the volume of the sample filled cannot exceed the volume of the sample tank. According to this principle, when VgadsKnown, it is obtained from formula (2):
then by Δ psv2＝p’sv2-psv2To obtain psv2＝p’sv2-Δpsv2Substituting formula (7) to obtain:
relationship between free space volume and sample mass:
Vsvf＝Vsv-Vs＝Vsv-ms/ρs (9)
in the formula, VsvIs the volume of free space of the sample tank, cm3；VsIs the volume of the sample, cm3。
Substituting formula (9) into p'sv2Solving equation (5) yields:
z in formula (10)sv2Is p'sv2The function of (2) also needs to be calculated iteratively.
Substituting the formula (10) and the formula (9) into the formula (8) to obtain a model of the known adsorption quantity and the pressure change value caused by adsorption for reversely deducing the sample dosage:
the equal sign of the upper type has m on both sidessThe solution needs to be carried out iteratively, and V needs to be satisfied at the same timesvf＝Vsv-Vs＞0。
The above equation (6) and equation (11) can respectively obtain the accuracy limit of the pressure sensor and the sample dosage limit, which are the test limit models of the isothermal adsorption experiment volumetric method.
Example 1 known adsorption and sample quantities against pressure sensor accuracy limits
Example calculations were performed knowing the shale sample mass ms111.0g, particle size 40-80 mesh, reference tank free space volume Vcv＝104.61cm3Volume of free space after filling of sample in a tanksvf＝120.44cm3Initial and final temperature T of the water bath1＝T230 ℃ gas component CH4The content is 100%, the gas compression factor is calculated by using a Dranchuk-Purvis-Robinson method, and the density is calculated by using a state equation. Other known parameters are input and the obtained pressure change value of the sample tank caused by adsorption is shown in the table 1.
TABLE 1 calculation of known parameters and calculation results for pressure sensor accuracy bounds
As can be seen from the examples, the adsorption amount of the rock sample to the gas is 1.0-0.001 m under the condition of the volumetric method experimental instrument related to the text3In the range of/t, the pressure change of the sample tank caused by adsorption is 0.054611-0.000054 MPa, the pressure change caused by smaller adsorption amount is smaller, and the adsorption amount is 0.001m3The pressure change value of the sample tank due to adsorption at/t was 0.000054 MPa. The adsorption capacity of the Chongqing sea phase shale is 1.29-6.15 m3T, when using thisThe accuracy limit of the pressure sensor of the isothermal adsorption instrument is 0.070468 MPa.
EXAMPLE 2 known sample adsorption and pressure sensor accuracy sample dosage limits
Example calculations were performed knowing that the density of a shale sample was 2.55g/cm3Reference tank volume of free space Vcv＝104.61cm3Volume V of free space of sample tanksv＝200.11cm3The precision of the pressure sensor is 0.01MPa, the pressure change value caused by adsorption actually corresponds to the precision of the pressure sensor of the sample tank, and the initial state and final state water bath temperatures T1＝T230 ℃ gas component CH4The content is 100%, the gas compression factor is calculated by using a Dranchuk-Purvis-Robinson method, and the density is calculated by using a state equation. Other known parameters entered and the desired sample amounts found are shown in table 2.
TABLE 2 calculation of known parameters and results of sample dosage limits
According to the example, under the condition of knowing the precision limit and the parameter of the experimental device of the volumetric method of the pressure sensor, if the adsorption capacity of the shale sample is 1.0-0.05 m3And t, the precision limit of the pressure sensor is 0.01MPa, and when the pressure sensor of the sample tank has a reading, the adsorption quantity can be measured, 26.4802-320.5413 g of shale samples are needed, and the smaller the adsorption quantity is, the larger the sample using quantity is needed. The adsorption capacity of the Chongqing sea phase shale is 1.29-6.15 m3And/t, the amount of the sample used when the isothermal adsorption apparatus is used is at least 4.3624 g.
Claims (8)
1. The method for determining the test limit of the isothermal adsorption experiment by the shale gas capacity method is characterized by being based on the isothermal adsorption experiment device by the shale gas capacity method, wherein the isothermal adsorption experiment device by the shale gas capacity method comprises a reference tank (3) and a sample tank (11), and a gas flow and vacuumizing interface valve (1) is connected to a gas inlet pipeline of the reference tank (3); the air outlet of the reference tank (3) is connected with the air inlet of the sample tank (11); a valve is arranged on a connecting pipeline of the reference tank (3) and the sample tank (11); the gas temperature sensor also comprises a first pressure sensor (4) and a second pressure sensor (8) which are respectively used for detecting the gas pressure in the reference tank (3) and the sample tank (11), and a temperature sensor (7) for detecting the gas temperature in the reference tank (3) and the sample tank (11);
the method comprises the following steps:
determining the free space volume of a sample tank (11) containing the sample;
determining the gas adsorption quantity of the sample according to the free space volume of the sample tank (11);
determination of the accuracy limit of the second pressure sensor: the gas adsorption quantity and the sample amount of the known sample are reversely deduced to obtain the gas pressure change in the balanced final state sample tank caused by adsorption, and the precision limit of the second pressure sensor is determined according to the gas pressure change value in the balanced final state sample tank caused by adsorption;
determination of minimum sample usage limit: the known gas adsorption capacity and the accuracy limit of the second pressure sensor are inversely extrapolated to obtain a minimum sample usage limit.
2. The shale gas capacity method isothermal adsorption experiment test limit determining method according to claim 1, wherein the accuracy limit of the second pressure sensor is determined specifically as follows:
calculating the gas pressure p in the sample tank in the equilibrium final state according to the gas adsorption amount and the sample amount of the samplesv2；
Then the gas pressure p in the final state sample tank is balanced when no adsorption occurs and is obtained by calculating the volume of the free space of the sample tanksv2Is recorded as p'sv2；
psv2And p'sv2Subtracting the two to obtain the gas pressure change delta p in the equilibrium final state sample tank caused by adsorptionsv2；
According to Δ psv2Determining a limit of accuracy of the second pressure sensor, wherein the limit of accuracy of the second pressure sensor is to satisfy more than Δ psv2A minimum value.
3. The shale gas capacity method isothermal adsorption experiment test limit determination method according to claim 1, characterized in that the determination of the free space volume of the sample tank (11) is specifically: opening a flowing gas and vacuumizing interface valve (1), filling non-adsorptive gas into a reference tank (3), closing the flowing gas and vacuumizing interface valve (1), opening a valve arranged on a connecting pipeline of the reference tank (3) and a sample tank (11), allowing the non-adsorptive gas to enter the sample tank (11), recording gas pressures in the reference tank (3) and the sample tank (11) in an initial state and an adsorption balance final state, closing the valve arranged on the connecting pipeline of the reference tank (3) and the sample tank (11), and repeating the processes until the highest experimental pressure is reached; and obtaining the free space volume of the sample tank (11) according to the gas pressure, the compression factor and the gas temperature in the reference tank (3) and the sample tank (11) in the initial state and the adsorption equilibrium final state.
4. The shale gas capacity method isothermal adsorption experiment test limit determination method according to claim 3, characterized in that the sample tank free space volume calculation formula is shown in formula (1):
in the formula, VsvfIs the free space volume, cm, of the sample after filling3；pcv1And psv1The gas pressure in the reference tank and the gas pressure in the sample tank are respectively MPa in the initial state; p is a radical ofsv2The gas pressure in the reference tank and the sample tank is MPa after the reference tank and the sample tank are communicated when the adsorption balance is in the final state; zcv1And Zsv1 eachCompression factors, Z, of gases in reference and sample tanks in the initial statesv2The compression factors of the gas in the reference tank and the gas in the sample tank are dimensionless when the adsorption balance is in a final state; r is gas constant 8.341X 10-6，MPa·m3·mol-1·K-1；T1、T2Water bath temperature at initial state and adsorption equilibrium final state, K; vcvFor reference to the volume of the free space of the tank, cm3。
5. The shale gas capacity method isothermal adsorption experiment test limit determination method according to claim 4, characterized in that the gas adsorption amount of the measured sample is specifically: opening a flow gas and vacuumizing interface valve (1), filling adsorptive gas into a reference tank (3), closing the flow gas and vacuumizing interface valve (1), opening a valve arranged on a connecting pipeline of the reference tank (3) and a sample tank (11), allowing the adsorptive gas to enter the sample tank (11), recording gas pressures in the reference tank (3) and the sample tank (11) in an initial state and an adsorption balance final state, closing the valve arranged on the connecting pipeline of the reference tank (3) and the sample tank (11), and repeating the processes until the highest experimental pressure is reached; and obtaining the gas adsorption quantity according to the gas pressure and the compression factor in the reference tank (3) and the sample tank (11) in the initial state and the adsorption equilibrium final state, as well as the gas temperature, the free space volume of the sample tank (11) and the mass of the sample in the sample tank (11).
6. The method for determining the test limit of the isothermal adsorption experiment of the shale gas capacity method according to claim 5, wherein the calculation formula of the gas adsorption amount in the first-time balance is as follows:
in the formula, msIs the mass of the sample, kg; vgadsVolume per unit mass of gas adsorbed in the sample in the standard condition, cm, during which this adsorption reaches equilibrium3/g；VmGas molar volume, 22.4L/mol; the amount of gas adsorbed after multiple adsorbtions is calculated by the following formula (3):
in the formula, ngadsIs the amount of species of gas adsorbed by the sample, mol; vgads|iThe volume of the gas accumulated and adsorbed by the unit mass sample after the ith adsorption equilibrium under the standard condition, which is referred to as gas adsorption capacity for short,10-3m3/kg。
7. the shale gas capacity method isothermal adsorption experiment test limit determining method according to claim 6, wherein the accuracy limit of the second pressure sensor is determined specifically as follows:
firstly, the gas adsorption quantity V in a single adsorption process is knowngadsThe gas pressure p in the sample tank at the equilibrium final state is obtained from the formula (2)sv2Comprises the following steps:
in the formula (4), VgadsWhen the adsorption does not occur, the gas pressure p in the final state sample tank is obtainedsv2Is recorded as p'sv2：
Subtracting the two to obtain the gas pressure change delta p in the equilibrium final state sample tank caused by adsorptionsv2Comprises the following steps:
according to Δ psv2Determining a limit of accuracy of the second pressure sensor, wherein the limit of accuracy of the second pressure sensor is to satisfy more than Δ psv2A minimum value.
8. The shale gas capacity method isothermal adsorption experiment test limit determining method according to claim 6, wherein the known gas adsorption amount and the accuracy limit of the second pressure sensor inversely deduct a sample usage limit, specifically:
knowing the gas adsorption V in a single adsorption processgadsThe gas pressure p in the sample tank at the equilibrium final state is obtained from the formula (2)sv2Comprises the following steps:
in the formula (4), VgadsWhen the adsorption does not occur, the gas pressure p in the final state sample tank is obtainedsv2Is recorded as p'sv2:
When V isgadsKnown, it is obtained from formula (2):
equilibrium end state sample tank gas pressure change Δ p due to adsorptionsv2＝p’sv2-psv2To obtain psv2＝p’sv2-Δpsv2Substituting formula (7) to obtain:
relationship between free space volume and sample mass after sample canning:
Vsvf＝Vsv-Vs＝Vsv-ms/ρs (9)
substituting formula (9) for formula (5) yields:
substituting equations (10) and (9) for equation (8) to obtain a model for back-estimating the amount of sample used given the amount of gas adsorbed and the accuracy limit of the second pressure sensor, equation (11):
in formula (11), Δ psv2The value is the precision limit of the second pressure sensor
In the case of (2), equation (11) is solved, and the minimum value obtained is the sample dose limit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110938364.4A CN113588489B (en) | 2021-08-16 | 2021-08-16 | Method for determining isothermal adsorption experiment test limit of shale gas capacity method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110938364.4A CN113588489B (en) | 2021-08-16 | 2021-08-16 | Method for determining isothermal adsorption experiment test limit of shale gas capacity method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113588489A true CN113588489A (en) | 2021-11-02 |
| CN113588489B CN113588489B (en) | 2023-06-23 |
Family
ID=78258119
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110938364.4A Active CN113588489B (en) | 2021-08-16 | 2021-08-16 | Method for determining isothermal adsorption experiment test limit of shale gas capacity method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113588489B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5744699A (en) * | 1995-03-02 | 1998-04-28 | Suzuki; Isao | Method and apparatus for adsorption measurement using temperature-compensated constant-volume adsorption apparatus |
| JP2005034772A (en) * | 2003-07-16 | 2005-02-10 | Mitsubishi Electric Corp | Nitrogen oxide treatment apparatus |
| CN103994960A (en) * | 2014-05-23 | 2014-08-20 | 中国石油大学(北京) | Coal/shale isothermal adsorption experiment method |
| CN106969999A (en) * | 2017-02-22 | 2017-07-21 | 清华大学 | A kind of true High Pressure Absorption kinetic test device and method of adsorbent |
| CN107063918A (en) * | 2016-12-28 | 2017-08-18 | 山东大学 | A kind of accurate adjustable coal grain adsorption-desorption rule of parameter determines device and method |
| US20180209889A1 (en) * | 2013-02-08 | 2018-07-26 | Schlumberger Technology Corporation | Apparatus and methodology for measuring properties of microporous material at multiple scales |
| CN109991120A (en) * | 2019-05-09 | 2019-07-09 | 陕西省煤田地质集团有限公司 | Rock covers isothermal adsorption/desorption and displacement test equipment and method under press strip part |
| CN110274863A (en) * | 2019-07-18 | 2019-09-24 | 广州海洋地质调查局 | A kind of determination method of shale oil enrichment aperture lower limit |
| CN111208037A (en) * | 2020-02-21 | 2020-05-29 | 武汉古生代检测科技有限公司 | Method for measuring absolute adsorption quantity of rock sample and method for measuring isothermal adsorption curve of rock sample |
| CN111521516A (en) * | 2019-12-11 | 2020-08-11 | 南通市飞宇石油科技开发有限公司 | Coal body gas adsorption and strain test system |
| CN112485150A (en) * | 2020-11-12 | 2021-03-12 | 武汉古生代检测科技有限公司 | High-precision gravimetric isothermal adsorption measurement method |
-
2021
- 2021-08-16 CN CN202110938364.4A patent/CN113588489B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5744699A (en) * | 1995-03-02 | 1998-04-28 | Suzuki; Isao | Method and apparatus for adsorption measurement using temperature-compensated constant-volume adsorption apparatus |
| JP2005034772A (en) * | 2003-07-16 | 2005-02-10 | Mitsubishi Electric Corp | Nitrogen oxide treatment apparatus |
| US20180209889A1 (en) * | 2013-02-08 | 2018-07-26 | Schlumberger Technology Corporation | Apparatus and methodology for measuring properties of microporous material at multiple scales |
| CN103994960A (en) * | 2014-05-23 | 2014-08-20 | 中国石油大学(北京) | Coal/shale isothermal adsorption experiment method |
| CN107063918A (en) * | 2016-12-28 | 2017-08-18 | 山东大学 | A kind of accurate adjustable coal grain adsorption-desorption rule of parameter determines device and method |
| CN106969999A (en) * | 2017-02-22 | 2017-07-21 | 清华大学 | A kind of true High Pressure Absorption kinetic test device and method of adsorbent |
| CN109991120A (en) * | 2019-05-09 | 2019-07-09 | 陕西省煤田地质集团有限公司 | Rock covers isothermal adsorption/desorption and displacement test equipment and method under press strip part |
| CN110274863A (en) * | 2019-07-18 | 2019-09-24 | 广州海洋地质调查局 | A kind of determination method of shale oil enrichment aperture lower limit |
| CN111521516A (en) * | 2019-12-11 | 2020-08-11 | 南通市飞宇石油科技开发有限公司 | Coal body gas adsorption and strain test system |
| CN111208037A (en) * | 2020-02-21 | 2020-05-29 | 武汉古生代检测科技有限公司 | Method for measuring absolute adsorption quantity of rock sample and method for measuring isothermal adsorption curve of rock sample |
| CN112485150A (en) * | 2020-11-12 | 2021-03-12 | 武汉古生代检测科技有限公司 | High-precision gravimetric isothermal adsorption measurement method |
Non-Patent Citations (4)
| Title |
|---|
| DUAN XIANGGANG ET.AL: "Shale high pressure isothermal adsorption curve and the production dynamic experiments of gas well", 《PETROLEUM EXPLORATION AND DEVELOPMENT》, pages 127 * |
| 周尚文;李奇;薛华庆;郭伟;李晓波;卢斌;: "页岩容量法和重量法等温吸附实验对比研究", 化工进展, no. 05, pages 1690 - 1697 * |
| 王瑞 等: "页岩和煤在容量法等温吸附实验中的误差对比", 《非 常 规 油 气》, vol. 8, no. 3, pages 43 - 57 * |
| 马行陟;柳少波;姜林;田华;郝加庆;: "页岩吸附气含量测定的影响因素定量分析", 天然气地球科学, no. 03, pages 487 - 493 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113588489B (en) | 2023-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103994943B (en) | A kind of coal/shale adsorption isotherm experiment device | |
| CN111208037B (en) | Method for measuring absolute adsorption quantity of rock sample and method for measuring isothermal adsorption curve of rock sample | |
| CN206057126U (en) | A kind of shale multi component adsorption experimental provision | |
| CN205138940U (en) | Test coal body gas adsorbs desorption heat effect experimental system | |
| CN104897514A (en) | Device for measuring danks surface gas adsorption and danks desorption curves | |
| CN112485175B (en) | Rock porosity measuring method and measuring device | |
| CN109470616B (en) | Multifunctional seepage testing system for rock | |
| CN111307685A (en) | Device and method for testing displacement, steady state and transient permeability of low-permeability rock | |
| CN109932272B (en) | CO (carbon monoxide) 2 Displacement experiment system and displacement experiment method | |
| CN205374214U (en) | Developments drill chip vary voltage desorption experimental system | |
| CN204718916U (en) | A kind of device measuring coal/shale surface gas absorption and desorption curve | |
| CN105628575B (en) | Shale property determination method and device and shale property determination instrument | |
| CN203908915U (en) | Coal/shale isothermal adsorption test device | |
| CN114720655A (en) | System and method for simultaneously measuring gas output characteristics of rock cores in different occurrence states | |
| CN106018165B (en) | A kind of shale multi component adsorption experimental calculation method | |
| CN116519531A (en) | Shale gas desorption amount calculation and test method under water-containing condition | |
| CN110187011B (en) | Simulation experiment device and simulation method for dynamic adsorption and desorption research | |
| CN114646571A (en) | Low-temperature high-pressure adsorption measuring device and method for measuring adsorption quantity of material gas | |
| CN113588489A (en) | Shale gas capacity method isothermal adsorption experiment test limit determination method | |
| CN209945932U (en) | A test instrument for rock gas high pressure adsorption | |
| CN107202743A (en) | A kind of Multi-example Static Adsorption test device and its method of testing | |
| CN214010979U (en) | Device for measuring methane adsorption amount of coal in gas-containing mixed gas under normal pressure | |
| CN114062517B (en) | Mixed gas adsorption testing device and method for shale gas and coalbed gas | |
| CN110927359A (en) | Experimental test device and method for gas loss content in low-permeability porous medium coring process | |
| CN112697632B (en) | Coal rock and shale bulk sample weight method isothermal adsorption measurement device and method |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |