CN117347410A - Shale porosity testing method under simulated formation pressure condition - Google Patents
Shale porosity testing method under simulated formation pressure condition Download PDFInfo
- Publication number
- CN117347410A CN117347410A CN202210735182.1A CN202210735182A CN117347410A CN 117347410 A CN117347410 A CN 117347410A CN 202210735182 A CN202210735182 A CN 202210735182A CN 117347410 A CN117347410 A CN 117347410A
- Authority
- CN
- China
- Prior art keywords
- shale
- pressure
- under
- formation pressure
- porosity
- 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
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 96
- 238000012360 testing method Methods 0.000 title claims abstract description 39
- 239000011148 porous material Substances 0.000 claims abstract description 56
- 238000000034 method Methods 0.000 claims abstract description 48
- 229920006395 saturated elastomer Polymers 0.000 claims abstract description 29
- 239000012530 fluid Substances 0.000 claims abstract description 25
- 239000003079 shale oil Substances 0.000 claims abstract description 12
- 238000005303 weighing Methods 0.000 claims abstract description 10
- 230000035699 permeability Effects 0.000 claims abstract description 6
- 238000004891 communication Methods 0.000 claims abstract description 4
- 239000011435 rock Substances 0.000 claims description 22
- 239000003350 kerosene Substances 0.000 claims description 20
- 238000005520 cutting process Methods 0.000 claims description 9
- 238000005481 NMR spectroscopy Methods 0.000 claims description 7
- 238000005406 washing Methods 0.000 claims description 2
- 238000000605 extraction Methods 0.000 claims 1
- 238000011161 development Methods 0.000 abstract description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 description 8
- 239000011707 mineral Substances 0.000 description 8
- 238000004364 calculation method Methods 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 238000001228 spectrum Methods 0.000 description 4
- 239000011800 void material Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000012937 correction Methods 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000003475 lamination Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 238000012512 characterization method Methods 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000004058 oil shale Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000009933 burial Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
Abstract
The invention belongs to the technical field of shale oil exploration and development, and relates to a shale porosity testing method under simulated formation pressure conditions. The method comprises the following steps: obtaining a shale sample; weighing shale samples and measuring the air permeability of the shale samples; measuring the effective communication pore volume and the total volume of shale of the shale sample, and then loading the saturated shale sample into an online nuclear magnetic clamp to measure nuclear magnetic signal quantity; calculating the pressure difference of shale under the formation pressure condition according to the overburden pressure and the fluid pressure of the formation where the shale core is positioned; and setting the overburden pressure and the fluid pressure of the shale core as shale formation pressure differential, testing shale nuclear magnetic signal quantity in a formation pressure differential state, and calculating shale pore volume and porosity under the formation pressure condition. The method can accurately measure the shale pore volume under the formation pressure condition, and the shale porosity value under the formation pressure condition is more accurate.
Description
Technical Field
The invention belongs to the technical field of shale oil exploration and development, and relates to a shale porosity testing method under simulated formation pressure conditions.
Background
The shale oil has deep burial depth and high formation pressure coefficient, under the combined action of high overburden pressure and high fluid pressure under the formation condition, the stress form of shale pores under the formation pressure condition is greatly different from that under the ground condition, and meanwhile, under the influence of stress release under the ground condition, the shale porosity value obtained by ground test is difficult to represent the shale porosity value under the formation pressure condition. The shale porosity parameter is the most basic parameter for shale reservoir characterization, accurately characterizes the porosity value under the shale stratum pressure condition, and has important significance for shale oil reserve evaluation, seepage capability, elastic development degree and the like.
Chinese patent application CN111946336a discloses a method for calculating nuclear magnetic porosity of a shale oil reservoir, which is a method for obtaining the nuclear magnetic porosity of the shale oil reservoir based on mineral analysis data, and calculates the nuclear magnetic porosity of the shale oil reservoir by the formula ip=100 (Kp plc+kc cal+kd dol+k). According to the method for acquiring the nuclear magnetic porosity of the shale oil reservoir based on the mineral analysis data, only rock scraps acquired by logging while drilling with low cost are needed to carry out mineral analysis, and then the mineral content fitting is applied to calculate the nuclear magnetic porosity; because the rock debris real object is subjected to mineral content measurement, the measured value is not influenced by the well bore environment, and the mineral content measurement precision is higher, so that the calculated nuclear magnetic pore degree value precision is higher. According to the method, rock scraps collected during logging while drilling can be utilized for mineral analysis, and then mineral content fitting is applied to calculate nuclear magnetic porosity, but shale porosity cannot be characterized under the formation pressure condition.
The Chinese patent application CN111650108A discloses a method and a device for measuring the effective porosity of shale rock, and relates to the field of oil and gas exploration, development, experiment and test, wherein the method for measuring the effective porosity of shale rock comprises the following steps: acquiring the total volume of the shale rock to be tested, the skeleton volume of the shale rock to be tested and the volume of particles and/or dust in the shale rock to be tested; determining the volume of the moisture-absorbing medium; correcting the skeleton volume by utilizing the volume of the moisture absorption medium to obtain a skeleton correction volume; and obtaining the effective porosity of the shale rock to be tested according to the total volume, the framework correction volume and the volume of particles and/or dust. The method solves the problem of inaccurate determination of the effective porosity of the fixed shale rock. According to the method, the effective porosity of the shale rock to be tested is obtained by testing the total volume of the rock core, the correction volume of the framework and the volume of particles and/or dust, but the test condition is that shale is crushed into particles and tested under the ground pressure condition, and the shale porosity under the formation pressure condition cannot be tested.
Chinese patent CN 105866002B discloses an accurate method for testing nuclear magnetic resonance porosity of oil shale, by testing different waiting time, echo interval saturated kerosene shale nuclear magnetic resonance T2 spectrum distribution and porosity, and comparing with helium porosity to calibrate waiting time and echo interval, nuclear magnetic resonance T2 spectrum distribution at the optimal waiting time and echo interval can accurately characterize physical properties of oil shale reservoir. The method is characterized in that factors influencing the nuclear magnetic resonance porosity testing precision of the oil-containing shale are attributed to the type and testing parameters (waiting time and echo interval) of sample saturated fluid, and the influence of shale sample hydration is eliminated through saturated kerosene; calibrating the optimal waiting time and echo interval by analyzing the T2 spectrum distribution change and the helium porosity; by adopting the method, the optimal test parameters capable of accurately characterizing the porosity of the oil-containing shale can be obtained by testing the nuclear magnetic resonance T2 spectrum distribution and the porosity of the saturated kerosene shale with different waiting time and echo intervals, the experimental operation is simple and easy, and the operability is strong. According to the method, the testing method of the porosity of the oil-containing shale is accurately characterized through a nuclear magnetic experiment, but the shale porosity cannot be tested under the formation pressure condition.
At present, the characterization method for the porosity of shale under the formation pressure condition is less, and the porosity of shale under the formation pressure condition cannot be tested, so that effective knowledge on shale reserves, productivity and seepage capability cannot be accurately realized.
Disclosure of Invention
In order to solve the problems, the invention provides a shale porosity testing method under simulated formation pressure conditions. The method can accurately measure the shale pore volume under the formation pressure condition, and the shale porosity value under the formation pressure condition is more accurate.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the invention provides a shale porosity testing method under a simulated formation pressure condition, which comprises the following steps of: selecting a shale rock sample of a target block for cutting and oil washing treatment to obtain a shale sample; weighing shale samples and measuring the air permeability of the shale samples; measuring the effective communication pore volume and the total volume of shale of the shale sample, and then loading the saturated shale sample into an online nuclear magnetic clamp to measure nuclear magnetic signal quantity; calculating the pressure difference of shale under the formation pressure condition according to the overburden pressure and the fluid pressure of the formation where the shale core is positioned; and setting the overburden pressure and the fluid pressure of the shale core as shale formation pressure differential, testing shale nuclear magnetic signal quantity in a formation pressure differential state, and calculating shale pore volume and porosity under the formation pressure condition.
Preferably, the pore volume V under shale formation pressure conditions is calculated pd ，
Wherein: v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the A is nuclear magnetic signal quantity of shale core under no pore pressure and surrounding pressure in a nuclear magnetic clamp holder, and is dimensionless; a is that d The method is characterized in that nuclear magnetic signal quantity of shale core in an online nuclear holder is zero-dimensional under the pressure difference state of shale under the formation pressure condition; v (V) p Shale pore volume in cm at ground conditions 3 。
Preferably, the porosity phi at shale formation pressure conditions d ，
Wherein: phi (phi) d Porosity in% under shale formation pressure conditions; v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 。
Preferably, when testing the shale nuclear magnetic signal under the stratum pressure difference state, testing the nuclear magnetic signal under the pore pressure at intervals until the difference value of the two nuclear magnetic signal is less than 5% in the last two times, and stopping testing.
Preferably, the method for measuring the communication pore volume and the porosity of the shale sample comprises the following steps: vacuumizing the shale sample, then carrying out high-pressure saturation on the shale sample by adopting fluid, and weighing the shale sample subjected to the high-pressure saturation in air to obtain the shale wet sample weight m s The method comprises the steps of carrying out a first treatment on the surface of the The saturated sample is completely soaked in the fluid and weighed, and the mass m is obtained l 。
Preferably, shale void volume V p And a porosity phiThe calculation formula of (2) is as follows:
V p ＝(m s -m g )/ρ o
φ＝V p /(m s -m l )/ρ o
wherein: v (V) p Shale pore volume, cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Phi is porosity,%; ρ o Is fluid density, g/cm 3 ；m s G is shale wet sample weight; m is m g G is the dry sample weight of shale; m is m l G is the weight of the saturated shale sample fully immersed in the fluid.
Preferably, the vacuum degree is less than or equal to-0.1 MPa when the vacuum pumping is carried out.
Preferably, the high pressure saturation is carried out at 20-30MPa and the fluid used is kerosene.
Preferably, when cutting shale rock samples, the shale core is cut into cylinders with diameters of 2-5 cm.
Compared with the prior art, the invention has the following advantages:
according to the method, shale is placed under an online nuclear magnetic device on the basis of the pore volume of the ground condition of the shale, the overburden pressure and the fluid pressure of the stratum are simulated, the shale porosity value under the condition of the stratum pressure is obtained, the shale pore volume under the condition of the stratum pressure is accurately measured through experimental means such as high-pressure saturation and online nuclear magnetic resonance, and the shale porosity value under the condition of the stratum pressure is obtained through calculation, so that the defects of the prior art are overcome.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.
FIG. 1 is a flow chart of a shale porosity testing method under simulated formation pressure conditions according to an embodiment of the invention.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, the singular forms also are intended to include the plural forms unless the context clearly indicates otherwise, and furthermore, it is to be understood that when the terms "comprises", "comprising" are used in this specification, they specify the presence of stated features, steps, operations, and combinations thereof.
In order to enable those skilled in the art to more clearly understand the technical scheme of the present invention, the technical scheme of the present invention will be described in detail with reference to specific embodiments.
Example 1
As shown in fig. 1, the method for measuring the effective porosity of shale oil comprises the following steps:
step 101, selecting shale rock samples of a certain research area, and cutting the shale rock core into cylindrical shale samples with the diameter of about 2.5cm by using a linear cutting technology.
Step 201, weighing a cylindrical shale sample by using an electronic balance to obtain the dry shale sample weight m g ，m g The shale air permeability value K, k=3.52 mD was measured = 27.625 g. .
Step 301, vacuuming the shale sample, vacuuming for 4 hours at a vacuum degree of-0.1 MPa, and then carrying out high-pressure saturated kerosene on the shale sample, and carrying out high-pressure saturated kerosene for 24 hours at 30 MPa.
Step 401, weighing the shale sample saturated by high pressure in air to obtain the wet shale sample weight m s 28.543g, the saturated sample is fully immersed in kerosene and weighed to obtain mass m l ＝18.135g。
Step 401, calculating shale void volume V p And the total volume V of shale, the calculation formula is:
V p ＝(m s -m g )/ρ o ＝(28.543-27.625)/0.8088＝1.135
V＝(m s -m l )/ρ o ＝(28.543-18.135)/0.8088＝12.868
wherein: v (V) p Shale pore volume, cm 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 ；ρ o Is kerosene density, g/cm 3 ；m s G is shale wet sample weight; m is m g G is the dry sample weight of shale; m is m l G is the weight of the saturated shale sample fully immersed in kerosene.
Step 501, loading a saturated shale sample into an online nuclear magnetic clamp to obtain a signal sum A, A= 663.12 in a shale saturation state.
Step 601, obtaining the formation overburden pressure F of the depth of the shale core according to the formation pressure data s =79 MPa and formation fluid pressure F l =59 MPa, calculated as shale formation pressure difference F,
F＝F s -F l ＝79-59＝20MPa
wherein: f (F) s Coating pressure on the stratum with MPa; f (F) l Is the formation fluid pressure, MPa; f is the formation pressure difference and MPa.
Step 701, setting the on-line nuclear magnetic clamp confining pressure F according to the shale formation lamination difference value and the pressure which can be born by the on-line nuclear magnetic clamp w =24 MPa and pore pressure F k =4mpa, where guarantee F w -F k ＝F。
Step 801, measuring the confining pressure F of shale core w =24 MPa and pore pressure F k Nuclear magnetic signal quantity in 4MPa state, testing once every 1 hour until the difference value of the nuclear magnetic signal quantity of the last two times is within 5%, stopping testing to obtain shale nuclear magnetic signal quantity A under formation pressure difference d ＝555.01。
Step 901, calculating pore volume V under shale formation pressure conditions pd ，
Wherein: v (V) pd Is the groundShale pore volume in cm under laminated pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the A is nuclear magnetic signal quantity of shale core under no pore pressure and surrounding pressure in a nuclear magnetic clamp holder, and is dimensionless; a is that d For shale core in an in-line core holder, confining pressure F w And pore pressure F k Nuclear magnetic signal quantity in state, dimensionless; v (V) p Shale pore volume in cm at ground conditions 3 。
Step 1001, calculating porosity phi under shale formation pressure conditions d ，
Wherein: phi (phi) d Porosity in% under shale formation pressure conditions; v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 。
The shale porosity at the final measured formation pressure condition was 7.38%.
Example 2
As shown in fig. 1, the method for measuring the effective porosity of shale oil comprises the following steps:
step 101, selecting shale rock samples of a certain research area, and cutting the shale rock core into cylindrical shale samples with the diameter of 5cm by using a linear cutting technology.
Step 201, weighing a cylindrical shale sample by using an electronic balance to obtain the dry shale sample weight m g ，m g The shale air permeability value K, k=0.85 mD was measured = 24.752 g. .
Step 301, vacuuming the shale sample, vacuuming for 4 hours at a vacuum degree of-0.1 MPa, and then carrying out high-pressure saturated kerosene on the shale sample, and carrying out high-pressure saturated kerosene for 24 hours at 30 MPa.
Step 401, weighing the shale sample saturated by high pressure in air to obtain the wet shale sample weight m s 25.168g, the saturated sample is fully immersed in kerosene and weighed to obtain mass m l ＝16.701g。
Step (a)401, calculating shale void volume V p And the total volume V of shale, the calculation formula is:
V p ＝(m s -m g )/ρ o ＝(25.168-24.752)/0.8088＝0.514
V＝(m s -m l )/ρ o ＝(25.168-16.701)/0.8088＝10.469
wherein: v (V) p Shale pore volume, cm 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 ；ρ o Is kerosene density, g/cm 3 ；m s G is shale wet sample weight; m is m g G is the dry sample weight of shale; m is m l G is the weight of the saturated shale sample fully immersed in kerosene.
Step 501, loading a saturated shale sample into an online nuclear magnetic clamp to obtain a signal sum A, A= 1052.86 in a shale saturation state.
Step 601, obtaining the formation overburden pressure F of the depth of the shale core according to the formation pressure data s =79 MPa and formation fluid pressure F l =59 MPa, calculated as shale formation pressure difference F,
F＝F s -F l ＝79-59＝20MPa
wherein: f (F) s Coating pressure on the stratum with MPa; f (F) l Is the formation fluid pressure, MPa; f is the formation pressure difference and MPa.
Step 701, setting the on-line nuclear magnetic clamp confining pressure F according to the shale formation lamination difference value and the pressure which can be born by the on-line nuclear magnetic clamp w =24 MPa and pore pressure F k =4mpa, where guarantee F w -F k ＝F。
Step 801, measuring the confining pressure F of shale core w =24 MPa and pore pressure F k Nuclear magnetic signal quantity in 4MPa state, testing once every 1 hour until the difference value of the nuclear magnetic signal quantity of the last two times is within 5%, stopping testing to obtain shale nuclear magnetic signal quantity A under formation pressure difference d ＝925.45。
Step 901, calculating pore volume V under shale formation pressure conditions pd ，
Wherein: v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the A is nuclear magnetic signal quantity of shale core under no pore pressure and surrounding pressure in a nuclear magnetic clamp holder, and is dimensionless; a is that d For shale core in an in-line core holder, confining pressure F w And pore pressure F k Nuclear magnetic signal quantity in state, dimensionless; v (V) p Shale pore volume in cm at ground conditions 3 。
Step 1001, calculating porosity phi under shale formation pressure conditions d ，
Wherein: phi (phi) d Porosity in% under shale formation pressure conditions; v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 。
Shale porosity at formation pressure conditions of an embodiment of the present invention is 4.32%.
Example 3
As shown in fig. 1, the method for measuring the effective porosity of shale oil comprises the following steps:
step 101, selecting shale rock samples of a certain research area, and cutting the shale rock core into cylindrical shale samples with the diameter of 2cm by using a linear cutting technology.
Step 201, weighing a cylindrical shale sample by using an electronic balance to obtain the dry shale sample weight m g ，m g The shale air permeability value K, k=0.08 mD was measured = 31.435 g. .
Step 301, vacuuming the shale sample, vacuuming for 4 hours at a vacuum degree of-0.1 MPa, and then carrying out high-pressure saturated kerosene on the shale sample, and carrying out high-pressure saturated kerosene for 24 hours at 30 MPa.
Step 401, for high pressure saturationWeighing the shale sample in air to obtain shale wet sample weight m s 31.751g, the saturated sample is fully immersed in kerosene and weighed to obtain mass m l ＝21.154g。
Step 401, calculating shale void volume V p And the total volume V of shale, the calculation formula is:
V p ＝(m s -m g )/ρ o ＝(31.751-31.435)/0.8088＝0.391
V＝(m s -m l )/ρ o ＝(31.751-21.154)/0.8088＝13.102
wherein: v (V) p Shale pore volume, cm 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 ；ρ o Is kerosene density, g/cm 3 ；m s G is shale wet sample weight; m is m g G is the dry sample weight of shale; m is m l G is the weight of the saturated shale sample fully immersed in kerosene.
Step 501, loading a saturated shale sample into an online nuclear magnetic clamp to obtain a signal sum A, A= 762.15 in a shale saturation state.
Step 601, obtaining the formation overburden pressure F of the depth of the shale core according to the formation pressure data s =79 MPa and formation fluid pressure F l =59 MPa, calculated as shale formation pressure difference F,
F＝F s -F l ＝79-59＝20MPa
wherein: f (F) s Coating pressure on the stratum with MPa; f (F) l Is the formation fluid pressure, MPa; f is the formation pressure difference and MPa.
Step 701, setting the on-line nuclear magnetic clamp confining pressure F according to the shale formation lamination difference value and the pressure which can be born by the on-line nuclear magnetic clamp w =24 MPa and pore pressure F k =4mpa, where guarantee F w -F k ＝F。
Step 801, measuring the confining pressure F of shale core w =24 MPa and pore pressure F k Nuclear magnetic signal quantity in 4MPa state, testing once every 1 hour until the difference value of the two last nuclear magnetic signal quantities is less than 5%, stopping testingObtaining shale nuclear magnetic signal quantity A under formation pressure difference d ＝875.24。
Step 901, calculating pore volume V under shale formation pressure conditions pd ，
Wherein: v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the A is nuclear magnetic signal quantity of shale core under no pore pressure and surrounding pressure in a nuclear magnetic clamp holder, and is dimensionless; a is that d For shale core in an in-line core holder, confining pressure F w And pore pressure F k Nuclear magnetic signal quantity in state, dimensionless; v (V) p Shale pore volume in cm at ground conditions 3 。
Step 1001, calculating porosity phi under shale formation pressure conditions d ，
Wherein: phi (phi) d Porosity in% under shale formation pressure conditions; v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 。
The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.
Claims (9)
1. The shale porosity testing method under the simulated formation pressure condition is characterized by comprising the following steps of: selecting a shale rock sample of a target block for cutting and oil washing treatment to obtain a shale sample; weighing shale samples and measuring the air permeability of the shale samples; measuring the effective communication pore volume and the total volume of shale of the shale sample, and then loading the saturated shale sample into an online nuclear magnetic clamp to measure nuclear magnetic signal quantity; calculating the pressure difference of shale under the formation pressure condition according to the overburden pressure and the fluid pressure of the formation where the shale core is positioned; and setting the overburden pressure and the fluid pressure of the shale core as shale formation pressure differential, testing shale nuclear magnetic signal quantity in a formation pressure differential state, and calculating shale pore volume and porosity under the formation pressure condition.
2. The method for testing shale porosity under simulated formation pressure according to claim 1, wherein the pore volume V under the condition of shale formation pressure is calculated pd ，
Wherein: v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the A is nuclear magnetic signal quantity of shale core under no pore pressure and surrounding pressure in a nuclear magnetic clamp holder, and is dimensionless; a is that d The method is characterized in that nuclear magnetic signal quantity of shale core in an online nuclear holder is zero-dimensional under the pressure difference state of shale under the formation pressure condition; v (V) p Shale pore volume in cm at ground conditions 3 。
3. The method for testing shale porosity under simulated formation pressure conditions as claimed in claim 2, wherein the shale formation pressure conditions have a porosity Φ d ，
Wherein: phi (phi) d Porosity in% under shale formation pressure conditions; v (V) pd Shale pore volume, cm, under formation pressure conditions 3 The method comprises the steps of carrying out a first treatment on the surface of the V is the total volume of shale, cm 3 。
4. The method for testing shale porosity under simulated formation pressure according to claim 1, wherein when testing shale nuclear magnetic signal under formation pressure differential condition, the nuclear magnetic signal under the pore pressure is tested at intervals until the difference between the two last nuclear magnetic signal is within 5%.
5. The method for testing shale porosity under simulated formation pressure conditions of claim 1, wherein the method for determining the connected pore volume and porosity of the shale sample comprises the steps of: vacuumizing the shale sample, then carrying out high-pressure saturation on the shale sample by adopting fluid, and weighing the shale sample subjected to the high-pressure saturation in air to obtain the shale wet sample weight m s The method comprises the steps of carrying out a first treatment on the surface of the The saturated sample is completely soaked in the fluid and weighed, and the mass m is obtained l 。
6. The method for testing shale porosity under simulated formation pressure conditions as claimed in claim 5, wherein shale pore volume V p And the porosity phi is calculated as:
V p ＝(m s -m g )/ρ o
φ＝V p /(m s -m l )/ρ o
wherein: v (V) p Shale pore volume, cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Phi is porosity,%; ρ o Is fluid density, g/cm 3 ；m s G is shale wet sample weight; m is m g G is the dry sample weight of shale; m is m l G is the weight of the saturated shale sample fully immersed in the fluid.
7. The method for testing shale porosity under simulated formation pressure condition of claim 5, wherein the vacuum degree is less than or equal to-0.1 MPa when the vacuum is applied.
8. The method for testing shale porosity under simulated formation pressure conditions as claimed in claim 5, wherein the fluid used is kerosene and is saturated at high pressure of 20-30 MPa.
9. The method for testing the elastic extraction degree of shale oil based on online nuclear magnetic resonance according to claim 1, wherein when the shale rock sample is cut, the shale core is cut into a cylinder with the diameter of 2-5 cm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210735182.1A CN117347410A (en) | 2022-06-27 | 2022-06-27 | Shale porosity testing method under simulated formation pressure condition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210735182.1A CN117347410A (en) | 2022-06-27 | 2022-06-27 | Shale porosity testing method under simulated formation pressure condition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117347410A true CN117347410A (en) | 2024-01-05 |
Family
ID=89363646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210735182.1A Pending CN117347410A (en) | 2022-06-27 | 2022-06-27 | Shale porosity testing method under simulated formation pressure condition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117347410A (en) |
-
2022
- 2022-06-27 CN CN202210735182.1A patent/CN117347410A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107727679B (en) | A kind of characterization Deep Carbonate Rocks petrophysics characterization method | |
| CN104697915B (en) | A kind of analysis method of shale microscopic void size and fluid distrbution | |
| RU2331057C2 (en) | Method and device for evaluation of physical parametres of undeground deposit of mineral wealth on base of study of rock fragments selected from this deposit | |
| Baldi et al. | A reevaluation of conventional triaxial test methods | |
| CN109060623B (en) | Compact sandstone pore size distribution joint characterization method | |
| CN110006738B (en) | Rock brittleness evaluation method based on stress-strain curve and scratch test | |
| WO2018164953A1 (en) | Absolute porosity and pore size determination of pore types in media with varying pore sizes using nmr | |
| JP4615997B2 (en) | A method for evaluating capillary pressure curves of rocks in underground reservoirs from measurements of rock debris. | |
| Ferrari et al. | Advances in the testing of the hydro-mechanical behaviour of shales | |
| CN103226089B (en) | Method for testing shale gas permeability | |
| CN111337408B (en) | Method for testing rock crack porosity by using low-field nuclear magnetic resonance equipment | |
| CN110296931B (en) | Characterization method and system for oil-water relative permeability information of tight sandstone | |
| CN110927035A (en) | Method for calculating saturation of irreducible tight sandstone bound water | |
| McPhee et al. | Routine core analysis | |
| US10436727B2 (en) | Prediction of gas production rates from time-dependent NMR measurements | |
| CN109061099B (en) | Nondestructive experimental evaluation method for damage degree of heterogeneous compact rock | |
| US20240027379A1 (en) | Method for quantitative evaluation on sensitivity of shale oil and gas reservoir to injected fluids | |
| US20050168220A1 (en) | Method of determining the permeability of an underground medium from NMR measurements of the permeability of rock fragments from the medium | |
| CN108268712B (en) | Method and device for determining capillary pressure of pore medium by nuclear magnetic resonance | |
| CN117347410A (en) | Shale porosity testing method under simulated formation pressure condition | |
| Guise et al. | Stress sensitivity of mercury-injection measurements | |
| CN115146483A (en) | Novel movable fluid use lower limit calculation method | |
| CN115901563A (en) | Method for calculating permeability of low-porosity and low-permeability reservoir by combining nuclear magnetic resonance and resistivity | |
| Harpalani | Compressibility of coal and its impact on gas production from coalbed reservoirs | |
| Trautwein | Permeability changes as a function of pore pressure in sandstones: laboratory experiments under uniaxial strain boundary conditions |
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 |