AU2020202464B2

AU2020202464B2 - Apparatus and method for measuring critical filling pressure

Info

Publication number: AU2020202464B2
Application number: AU2020202464A
Authority: AU
Inventors: Yonglin DU; Yuhong LEI; Naigui Liu; Xiaorong Luo; Jianzhao YAN; Likuan ZHANG
Original assignee: Northeast Petroleum Univ; Institute of Geology and Geophysics of CAS; Northeast Petroleum University
Current assignee: Institute of Geology and Geophysics of CAS; Northeast Petroleum University
Priority date: 2019-04-10
Filing date: 2020-04-09
Publication date: 2021-03-11
Anticipated expiration: 2040-04-09
Also published as: CN110044790A; AU2020202464A1; CN110044790B

Abstract

The present disclosure provides an apparatus and a method for measuring the critical filling pressure. The apparatus for measuring comprises: a critical filling pressure, characterized in comprising a micro advection pump, an intermediate container, a pressure sensor, a monitoring module and a core holder, wherein: the core holder is used for holding an impermeable object for calibration and a core to be measured; the micro advection pump is connected to one end of the intermediate container through a first pipe, for injecting first liquid into the intermediate container at a preset flow rate; the other end of the intermediate container is connected to the core holder through a second pipe, for injecting second liquid into the core holder, and the pressure sensor is connected onto the second pipe between the intermediate container and the core holder; the monitoring module is electrically connected to the pressure sensor, and is used for monitoring in real time the pressure of the pressure sensor that varies with time when an impermeable object and a core to be measured are held in the core holder. The present disclosure can quickly and accurately measure the critical filling pressure of a core, with a measurement result thereof having a very small error compared with an actual value. 1/4 18 22 19 5 14 17 13 4 22 9 16 3 12 15 FIG. 1

Description

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FIG. 1

Apparatus and Method for Measuring Critical Filling Pressure

Technical Field

The disclosure relates to the field of petroleum exploration, in particular to a core

parameter measurement technology, and specifically to an apparatus and a method for

measuring a critical filling pressure.

Background

The proportion of low permeability and tight oil and gas reservoirs in China's oil

and gas resources increases year by year, and the critical filling pressure is a key

parameter in the reservoir-forming study of such oil and gas reservoirs, but the critical

filling pressure cannot be measured accurately in the prior art. In order to measure the

critical fill pressure, the prior art proposes a method of measuring critical filling

pressure using an RLC (Radio Link Control) bridge. The basic principle of the method

is that resistivity of a saturated-water core increases when oil is injected into the core,

so that injection pressure at which oil begins to enter the core is detected by measuring

the resistivity of the core by the RLC bridge, and which is the critical filling pressure.

However, when the oil begins to enter the core, there is a very small change in the

resistivity of the core, and the relationship between the oil content and distribution and

the core resistivity is multi-solvability, and thus the method has a low sensitivity and a

large error.

Summary of the Disclosure

Embodiments of the present disclosure provide an apparatus and a method for

measuring a critical filling pressure, which can at least alleviate the problem that an

existing measurement technology has a low sensitivity and a large error, and can quickly

and accurately measure the critical filling pressure of a core, with a measurement result

thereof having a very small error compared with an actual value.

In one aspect, an embodiment of the present disclosure provides an apparatus for

measuring a critical filling pressure, comprising a micro advection pump, an

intermediate container, a pressure sensor, a monitoring module and a core holder,

wherein:

17393470_1 (GHMatters) P46064AU00 the core holder is used for holding an impermeable object for calibration and a core to be measured; the micro advection pump is connected to one end of the intermediate container through a first pipe, for injecting first liquid into the intermediate container at a preset flow rate; the other end of the intermediate container is connected to the core holder through a second pipe, for injecting second liquid into the core holder, and the pressure sensor is connected onto the second pipe between the intermediate container and the core holder; the monitoring module is electrically connected to the pressure sensor, and is used for monitoring in real time the pressure of the pressure sensor that varies with time when an impermeable object and a core to be measured are held in the core holder. In one embodiment, the intermediate container is disposed in a vertical direction, a low end thereof being connected to the micro advection pump and an upper end thereof being in communication with the core holder. In one embodiment, density of the first liquid is greater than that of the second liquid. In one embodiment, the apparatus for measuring the critical filling pressure further comprises a container connected onto the second pipe between the intermediate container and the core holder through a third pipe, for containing the second liquid. In one embodiment, the apparatus for measuring the critical filling pressure further comprises a vacuum pump which is connected to the third pipe through a fourth pipe. In one embodiment, the apparatus for measuring the critical filling pressure comprises: a valve configured on the second pipe; a valve configured on the third pipe; a valve configured on the fourth pipe. In one embodiment, the apparatus for measuring the critical filling pressure further comprises an annular pressure pump which is connected to the core holder through a

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17393470_1 (GHMatters) P46064AU00 fifth pipe. In one embodiment, the apparatus for measuring the critical filling pressure further comprises a pressure gauge which is configured on the fifth pipe.

In another aspect, an embodiment of the present disclosure provides a method for

measuring a critical filling pressure, the method comprises:

loading the impermeable object into the core holder;

opening the micro advection pump after applying a confining pressure to the core

holder to a preset value, to fill the intermediate container at a preset flow rate until a

preset time;

recording, by the monitoring module, a curve showing relationship of the pressure

of the pressure sensor that varies with time, as a calibration curve;

loading the core to be measured into the core holder;

holder to the preset value, to fill the intermediate container at the preset flow rate until

the preset time;

recording, by the monitoring module, relationship of the pressure of the pressure

sensor that varies with time, as a measurement curve;

comparing the calibration curve and the measurement curve to obtain the critical

filling pressure.

In one embodiment, prior to loading the impermeable object into the core holder

and loading the core to be measured into the core holder, the method further comprises:

opening a vacuum pump to vacuumize the intermediate container and the second

and third pipes connected to the intermediate container so that the second liquid in a

beaker enters the intermediate container and the second and third pipes connected to

the intermediate container.

In one embodiment, recording, by the monitoring module, a curve showing

relationship of the pressure of the pressure sensor that varies with time, includes:

recording, by the monitoring module at a preset sampling time interval, a curve

showing relationship of the pressure of the pressure sensor that varies with time.

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17393470_1 (GHMatters) P46064AU00

From the above description, the present disclosure provides an apparatus and a

method for measuring a critical filling pressure, which can solve the problem that an

thereof having a very small error compared with an actual value. Brief Description of the Drawings

In order to more clearly explain the embodiments of the disclosure or the technical

solution in the prior art, drawings that need to be used in the description in embodiments

or the prior art will be simply introduced below, obviously the drawings in the following

description are some examples of the disclosure, for persons ordinarily skilled in the

art, it is also possible to obtain other drawings according to these drawings without

making creative efforts.

FIG. 1 is a structural schematic diagram of an apparatus for measuring a critical

filling pressure according to an embodiment of the present disclosure.

FIG. 2 is a flow schematic diagram of a method for measuring a critical filling

pressure according to an embodiment of the present disclosure.

FIG. 3 is a schematic diagram showing comparison between a calibration curve

and a measurement curve according to an embodiment of the present disclosure.

FIG. 4 is a partially enlarged schematic diagram of FIG. 3.

FIG. 5 is a flow schematic diagram of a specific application example of the method

for measuring the critical filling pressure of the present disclosure.

Detailed Description of the Preferred Embodiments Hereinafter the technical solution in the embodiments of the present disclosure will be described clearly and integrally in combination with the accompanying drawings in the embodiments of the present disclosure, and obviously the described embodiments are merely part of the embodiments, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments that are obtained by persons skilled in the art without making creative efforts fall within the protection scope of the present disclosure.

An embodiment of the present disclosure provides specific implementation of an

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17393470_1 (GHMatters) P46064AU00 apparatus for measuring a critical filling pressure, and referring to FIG. 1, the apparatus for measuring a critical filling pressure specifically comprises: a micro advection pump 1, an intermediate container 4, a pressure sensor 11, a monitoring module 12 and a core holder 13, in which: the core holder 13 is used for holding an impermeable object for calibration and a core to be measured; in a specific example, the impermeable object may be selected to be stainless steel in the shape of a cylinder; the micro advection pump 1 is connected to one end of the intermediate container

4 through a first pipe 16, for injecting first liquid 21 into the intermediate container 4 at

a preset flow rate;

in a specific example, the preset flow rate may be 0.02 ml/min; the first liquid 21

may be water or other non-compressible liquid;

the other end of the intermediate container 4 is connected to the core holder 13

through a second pipe 17, for injecting second liquid 22 into the core holder 13, and the

pressure sensor 11 is connected onto the second pipe 17 between the intermediate

container 4 and the core holder 13;

in a specific example, the intermediate container 4 is disposed in a such a direction

that:

a portion of the intermediate container 4 that is connected to the micro advection

pump 1 is directed downwards, and a portion of the intermediate container 4 that is in

communication with the core holder 13 is directed upwards.

In a specific example, the second liquid 22 may be kerosene or other oil liquid.

The monitoring module 12 is electrically connected to the pressure sensor 11, and

is used for monitoring in real time the pressure of the pressure sensor 11 that varies with

time when an impermeable object and a core to be measured are held in the core holder

13.

In a specific example, the capacity of the intermediate container 4 may be 200 ml.

The apparatus for measuring further comprises a container 6 connected onto the

second pipe 17 between the intermediate container 4 and the core holder 13 through a 5

17393470_1 (GHMatters) P46064AU00 third pipe 18, for containing the second liquid 22.

In a specific example, the container 6 may be a beaker, such as a beaker of 10 x 10

cm and of 25 cm length, the wall thickness thereof may be 5 mm, the beaker contains

kerosene, and the density of kerosene may be 0.896 g/cc.

The apparatus for measuring further comprises a vacuum pump 7 which is

connected to the third pipe 18 through a fourth pipe 19.

A valve 9 is configured on the second pipe 17.

A valve 5 is configured on the third pipe 18.

A valve 8 is configured on the fourth pipe 19.

The apparatus for measuring further comprises an annular pressure pump 15 which

is connected to the core holder 13 through a fifth pipe 20.

The apparatus for measuring further comprises a pressure gauge 14 which is

configured on the fifth pipe 20.

From the above description, the present disclosure provides an apparatus for

measuring a critical filling pressure, which can solve the problem existed in a

measurement technology in prior art with a low sensitivity and a large error. And the

present disclosure can quickly and accurately measure the critical filling pressure of a

core, with a measurement result thereof having a very small error compared with an

actual value.

An embodiment of the present disclosure provides specific implementation of a

method for measuring a critical filling pressure, and referring to FIG. 2, the method for

measuring a critical filling pressure specifically comprises:

A step 100: loading the impermeable object into the core holder.

It may be understood that the tightness of the apparatus for measuring should be

checked prior to the start of the measurement of the critical fill pressure, specifically by

opening the micro advection pump, loading a stainless steel cylinder into the core

holder, turning on the monitoring module and the pressure sensor, pressurizing the

apparatus for measuring to a preset value, turning off the micro advection pump, and

checking whether the pressure is decaying by the pressure sensor and the monitoring

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17393470_1 (GHMatters) P46064AU00 module. In a specific example, the preset value may be 10 MPa.

A step 200: opening the micro advection pump after applying a confining pressure

to the core holder to a preset value, to fill the intermediate container at a preset flow

rate until a preset time.

It may be understood that the confining pressure is applied to the core holder in

order to simulate the underground pressure environment, and the preset value should

be consistent according to the pressure of the stratum where the core to be measured is

located, and which may be 25 MPa in a specific example. The preset time shall not

be less than 6400s.

A step 300: recording, by the monitoring module, a curve showing relationship of

the pressure of the pressure sensor that varies with time, as a calibration curve.

A step 400: loading the core to be measured into the core holder.

It may be understood that prior to the steps 100 and 400, the method further

comprises:

opening a vacuum pump to vacuumize the intermediate container and the second

and third pipes connected to the intermediate container so that the second liquid in the

container enters the intermediate container and the second and third pipes connected to

the intermediate container.

In accordance with the number of cores to be measured, the cores to be measured

may be sequentially loaded into the core hold to measure a plurality of cores to be

measured.

A step 500: opening the micro advection pump after applying a confining pressure

to the core holder to the preset value, tofill the intermediate container at the preset flow

rate until the preset time.

A step 600: recording, by the monitoring module, relationship of the pressure of

the pressure sensor that varies with time, as a measurement curve.

It may be understood that the monitoring module records a curve showing

relationship of the pressure of the pressure sensor that varies with time, at a preset

sampling time interval which may be 5 s in a specific example.

7 17393470_1 (GHMatters) P46064AU00

A step 700: comparing the calibration curve and the measurement curve to obtain

the critical filling pressure.

From the above description, the embodiment of the present disclosure provides a

thereof having a very small error compared with an actual value.

To further illustrate the solution, the present disclosure further provides a specific

application example of the method for measuring a critical filling pressure, with

reference to FIGS. 3, 4 and 5. The specific application example of the method for

measuring the critical filling pressure includes specifically the following:

It may be understood that each of the measurement data in the method for

measuring the critical filling pressure is one data point in FIGS. 3 and 4, but because

there is an enormous quantity of data points in FIG. 3, the data points are specifically

shown as one line in the figure.

SO: opening the micro advection pump 1, loading a stainless steel cylinder into the

core holder 13, turning on the monitoring module 12 and the pressure sensor 11,

pressurizing the apparatus for measuring to 10 MPa, turning off the micro advection

pump 1, and checking whether the pressure is decaying by the pressure sensor 11 and

the monitoring module 12, and after the checking is completed, opening the valve 10

and unloading the pressure of the apparatus for measuring.

Sl: opening the vacuum pump 7, the valve 5 and the valve 8, and closing the valve

10 to vacuumize the intermediate container 4 and the second and third pipes 17 and 18

connected to the intermediate container 4 so that the second liquid 22 in the container

6 enters the intermediate container 4 and the second and third pipes 17 and 18 connected

to the intermediate container 4.

S2: closing the valve 3, the valve 5 and the valve 8, and opening the valve 2 and

the valve 9, and opening the micro advection pump 1 after applying the confining

pressure to the core holder 13 to 25 MPa, to fill the intermediate container 4 at a flow

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17393470_1(GHMatters) P46064AU00 rate of 0.02ml/min until 6400 s.

S3: recording, by the monitoring module 12 at a sampling time interval of 5 s, a

curve showing relationship of the pressure of the pressure sensor 11 that varies with

time, as a calibration curve, and opening the valve 10 and unloading the pressure of the

apparatus for measuring.

S4: opening the vacuum pump 7, the valve 5 and the valve 8, and closing the valve

to the intermediate container 4.

S5: loading the core I to be measured into the core holder 13, and closing the valve

10.

S6: opening the micro advection pump 1 after applying a confining pressure to the

core holder 13 to 25 MPa, to fill the intermediate container at a flow rate 0.02ml/min

until 6400s.

S7: recording, by the monitoring module 12 at a sampling time interval of 5 s,

relationship of the pressure of the pressure sensor 11 that varies with time, as a

measurement curve.

S8: opening the valve 10 and unloading the pressure of the apparatus for

measuring, and loading the core 2 to be measured into the core holder 13.

S9: opening the micro advection pump 1 after applying a confining pressure to the

until 6400s.

S10: recording, by the monitoring module 12 at a sampling time interval of 5 s,

relationship of the pressure of the pressure sensor I Ithat varies with time, as a

measurement curve.

S11: comparing the calibration curve and the measurement curve to obtain the

critical filling pressure of the two cores 1 and 2, which are 1.66 MPa (see point A in

FIG. 3) and 0.22 MPa (see point B in FIG. 3 and FIG. 4), respectively.

9 17393470_1 (GHMatters) P46064AU00

From the above description, the present disclosure provides an apparatus and a

thereof having a very small error compared with an actual value.

Specific embodiments of the present specification have been described in the

above. Other embodiments fall within the scope of the appended claims. In some

cases, the actions or steps recited in the claims may be performed in a different order

from that in the embodiments and still achieve the desired results. In addition, the

processes depicted in the drawings do not necessarily require a particular order or a

sequential order shown in order to achieve the desired results.

Although the embodiment of the specifications provides the method operation

steps as described in the embodiment or the flowcharts, more or less operation steps

may be included based on the conventional or non-creative means. The order of the

steps listed in the embodiments is merely one of various execution orders of the steps,

rather than a unique execution order. At an actual apparatus or a terminal product, the

steps may be performed in sequence or in parallel according to the methods illustrated

in the embodiments or drawings (e.g., by a parallel processor or under a multi

threaded processing environment and even a distributed data processing

environment). The term "comprise", "include" or any other variant intends to cover

the non-exclusive inclusions, so that a process, a method, a commodity or a device

comprising a series of elements comprise not only those elements, but also other

elements not explicitly listed, or further comprise inherent elements of such process,

method, commodity or device. In a case where there is no further limitation, it does

not exclude other identical elements existing in the process, method, commodity or

device comprising the elements.

The above description is merely an example of the embodiment of the present

specification, and is not intended to limit the embodiment of the present specification.

Various modifications and variations may be made to the embodiments of the present

10 17393470_1 (GHMatters) P46064AU00 specification by those skilled in the art. Any modifications, equivalents, improvements, etc. made within the spirit and principle of the embodiments of the present specification shall be included within the scope of the claims of the embodiments of the present specification.

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Claims

Claims 1. An apparatus for measuring a critical filling pressure, characterized in

comprising a micro advection pump; an intermediate container; a pressure sensor; a

monitoring module; and a core holder,

wherein the core holder is used for holding an impermeable object for calibration

and a core to be measured,

wherein the micro advection pump is connected to one end of the intermediate

container through a first pipe, for injecting first liquid into the intermediate container at

a preset flow rate,

wherein the other end of the intermediate container is connected to the core holder

through a second pipe, for injecting second liquid into the core holder, and the pressure

sensor is connected onto the second pipe between the intermediate container and the

core holder,

wherein the monitoring module is electrically connected to the pressure sensor, for

monitoring in real time the pressure of the pressure sensor that varies with time when

an impermeable object and a core to be measured are held in the core holder,

wherein the intermediate container is disposed in a vertical direction, a low end

thereof is connected to the micro advection pump and an upper end thereof is in

communication with the core holder,

wherein density of the first liquid is greater than that of the second liquid,

wherein the apparatus for measuring further comprises an annular pressure pump

which is connected to the core holder through a fifth pipe.
2. The apparatus for measuring a critical filling pressure according to claim 1,

further comprising a container connected onto the second pipe between the intermediate

container and the core holder through a third pipe, for containing the second liquid.
3. The apparatus for measuring a critical filling pressure according to claim 2,

further comprising a vacuum pump which is connected to the third pipe through a fourth

pipe.
4. The apparatus for measuring a critical filling pressure according to claim 3, 12

17393470_1 (GHMatters) P46064AU00 wherein the second pipe is configured with a valve, the third pipe is configured with a valve, the fourth pipe is configured with a valve.
5. The apparatus for measuring a critical filling pressure according to claim 1, characterized in further comprising a pressure gauge which is configured on the fifth pipe.
6. A method for measuring a critical filling pressure by utilizing the apparatus for measuring a critical filling pressure according to any one of claims I to 5, comprising: loading the impermeable object into the core holder; opening the micro advection pump after applying a confining pressure to the core holder to a preset value, to fill the intermediate container at a preset flow rate until a preset time; recording, by the monitoring module, a curve showing relationship of the pressure of the pressure sensor that varies with time, as a calibration curve; loading the core to be measured into the core holder; opening the micro advection pump after applying a confining pressure to the core holder to the preset value, to fill the intermediate container at the preset flow rate until the preset time; recording, by the monitoring module, relationship of the pressure of the pressure sensor that varies with time, as a measurement curve; comparing the calibration curve and the measurement curve to obtain the critical filling pressure.
7. The method according to claim 6, wherein prior to loading the impermeable object into the core holder and loading the core to be measured into the core holder, the method further comprises: opening a vacuum pump to vacuumize the intermediate container and the second and third pipes connected to the intermediate container so that the second liquid in the container enters the intermediate container and the second and third pipes connected to

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17393470_1 (GHMatters) P46064AU00 the intermediate container.
8. The method according to claim 6, wherein, recording, by the monitoring module, a curve showing relationship of the pressure of the pressure sensor that varies with time, comprises: recording, by the monitoring module at a preset sampling time interval, a curve showing relationship of the pressure of the pressure sensor that varies with time.
9. The apparatus for measuring a critical filling pressure according to any one of claims 1 to 5, wherein, the first liquid is water, and the second liquid is oil liquid.
10. The apparatus for measuring a critical filling pressure according to claim 9, wherein, the second liquid is kerosene.

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