CN217505575U - Rock stress sensitivity testing device - Google Patents

Abstract

The utility model relates to a rock stress sensitivity testing arrangement. The rock stress sensitivity testing device comprises: a thermostat; the core holder is positioned in the constant temperature box and used for holding a core; the liquid annular pressure pump is connected with the core holder through an annular pressure pipeline so that the core holder obtains confining pressure; the sealed test air source is connected with the core holder through a sealed test pipeline; the gas flowmeter is connected with the outlet of the rock core holder through a gas outlet pipeline; the displacement gas source is connected with the inlet of the core holder through a gas inlet pipeline; and the gas detection bottle is connected to the gas inlet pipeline or the gas outlet pipeline through a branch pipeline so as to detect whether gas is discharged from the branch pipeline when the sealed test gas source charges gas into the core holder. When the device is used, the air tightness of the core holder is tested by using gas, confining pressure is increased by using liquid, the core is effectively prevented from being polluted by liquid inlet due to sealing failure of a rubber sleeve of the core holder, and the advantages of liquid pressurization and high pressure relief speed are achieved.

Description

Rock stress sensitivity testing device

Technical Field

The utility model relates to a rock stress sensitivity testing arrangement.

Background

Permeability is one of the important physical parameters of rock. Along with the change of the effective stress on the reservoir, the reservoir can generate elastic or plastic deformation, so that the pore space of the reservoir is changed continuously, and the permeability is changed along with the change, and the phenomenon is called as reservoir stress sensitivity.

At present, indoor core experiment methods are mainly adopted for reservoir stress sensitivity research in the industry, and permeability under different net overbalances is generally determined by changing confining pressure. For example, chinese patent publication No. CN111999183A discloses a hard and brittle shale fracture testing and consolidating apparatus, which comprises a triaxial core holder, a hoop pressure pump, an axial pressure control system, and a gas flow meter, wherein the triaxial core holder for holding a shale sample is respectively connected to the hoop pressure pump and the axial pressure control system, a control valve and a high-precision pressure sensor are arranged between the triaxial core holder and the hoop pressure pump, and the gas flow meter is connected to an outlet valve of the triaxial core holder.

In the prior art, confining pressure is generally obtained by filling a core holder with high-pressure gas or high-pressure liquid. When using high-pressure gas to obtain confined pressure, because gas can be compressed, when adjusting confined pressure, high-pressure gas pressurization and pressure release time are longer, and work efficiency is lower. When the confining pressure is increased by using high-pressure liquid, the liquid is almost incompressible, so that the pressurizing and pressure releasing time of the high-pressure liquid is short and the working efficiency is high when the confining pressure is adjusted; however, if the rubber sleeve of the core holder is not well sealed, high-pressure fluid can enter the core to cause core pollution, and the accuracy of a test result is influenced.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a rock stress sensitivity testing arrangement to when adjusting confining pressure through high-pressure liquid among the solution prior art, cause the technical problem that the rock core pollutes easily.

The utility model discloses well rock stress sensitivity testing arrangement adopts following technical scheme:

the rock stress sensitivity testing device comprises a constant temperature box, wherein a rock core holder for holding a rock core is arranged in the constant temperature box; the core holder is connected with a hydraulic annular pressure pump through an annular pressure pipeline so as to enable the core holder to obtain confining pressure; the core holder is connected with a sealing test air source through a sealing test pipeline; the outlet of the rock core holder is connected with a gas flowmeter through a gas outlet pipeline; the inlet of the core holder is connected with a displacement gas source through a gas inlet pipeline; and the gas inlet pipeline or the gas outlet pipeline is connected with a gas detection bottle through a branch pipeline so as to detect whether gas is discharged from the branch pipeline when the sealed test gas source charges gas into the core holder.

The beneficial effects are that: the utility model simulates the formation temperature through the constant temperature box, so that the data is closer to the real environment; and the air tightness of the core holder is tested by using gas, and the confining pressure is increased by using liquid, so that the pollution of the liquid inlet of the core due to the sealing failure of a rubber sleeve of the core holder is effectively prevented, and the advantages of quick liquid pressurization and pressure relief are achieved.

As a further improvement, the branch pipeline comprises a first branch line and a second branch line which are connected in series, and a separation bottle is arranged between the first branch line and the second branch line.

The beneficial effects are that: the design can be used for detecting the air tightness by using gas and liquid.

As a further improvement, a first displacement pressure gauge and a second displacement pressure gauge are connected to the air inlet pipeline, and the range of the first displacement pressure gauge is larger than that of the second displacement pressure gauge.

The beneficial effects are that: according to the height of measuring gas pressure, use the displacement manometer of high-range or low-range to avoid preventing that gas pressure from too high dashing out the manometer, can accurately obtain the experiment pressure value simultaneously.

As a further improvement, the first displacement pressure gauge and the second displacement pressure gauge are both electronic pressure gauges.

The beneficial effects are that: the measured value of the electronic pressure gauge is displayed in real time, the reading is rapid, the precision is high, and the calibration and zero setting are convenient.

As a further improvement, the liquid annular pressure pump is a water annular pressure pump.

The beneficial effects are that: the water cost is low, the viscosity is low, and the water is not easy to remain in the core holder.

As a further improvement, a multi-way valve is arranged on the air inlet pipeline, and the branch pipeline is connected to the multi-way valve.

The beneficial effects are that: by the design, the branch pipeline is convenient to connect on the air inlet pipeline.

As a further improvement, a sealing test pressure gauge is arranged on the sealing test pipeline.

The beneficial effects are that: the design is favorable for ensuring the initial pressure of confining pressure, and the phenomenon that the rock core is compacted due to overhigh pressure to influence the change of permeability is avoided.

As a further improvement, the sealing test air source is a gas cylinder.

As a further improvement, the gas cylinder is a nitrogen gas cylinder.

The beneficial effects are that: the cost of the nitrogen is lower.

As a further improvement, the gas flow meter is a soap film flow meter.

The beneficial effects are that: the soap film flowmeter is particularly suitable for the situations of low permeability and low gas flow rate.

The above-described preferred embodiments may be adopted alone, or two or more embodiments may be arbitrarily combined when they can be combined, and the embodiments formed by the combination are not specifically described here and are included in the description of the present patent.

Drawings

FIG. 1 is a schematic structural diagram of a rock stress sensitivity testing device according to the present invention;

in the figure: 1. a gas detection bottle; 2. separating the bottles; 3. displacing the gas source; 4. a first displacement pressure gauge; 5. a second displacement pressure gauge; 6. a six-way valve; 7. a core holder; 8. a thermostat; 9. sealing the test gas source; 10. sealing the test pressure gauge; 11. a liquid annular pressure pump; 12. a gas flow meter; 13. a first valve; 14. a second valve; 15. a third valve; 16. a fourth valve; 17. a first pressure relief valve; 18. a first pressure control valve; 19. a fifth valve; 20. a second pressure control valve; 21. a second pressure relief valve; 22. a third pressure control valve; 23. a third pressure relief valve; 24. and a sixth valve.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention, i.e., the described embodiments are only some, but not all embodiments of the invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiment of the present invention, all other embodiments obtained by the person skilled in the art without creative work belong to the protection scope of the present invention.

It is noted that relational terms such as the terms first and second, and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the statement that "comprises an … …" is intended to indicate that there are additional elements of the same process, method, article, or apparatus that comprise the element.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" when they are used are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those skilled in the art from the specific situation.

In the description of the present invention, unless otherwise explicitly specified or limited, the term "provided" may be used in a broad sense, for example, the object of "provided" may be a part of the body, or may be arranged separately from the body and connected to the body, and the connection may be a detachable connection or a non-detachable connection. The specific meaning of the above terms in the present invention can be understood by those skilled in the art from the specific situation.

The present invention will be described in further detail with reference to examples.

The utility model discloses well rock stress sensitivity testing arrangement's embodiment 1:

as shown in fig. 1, the rock stress sensitivity testing device comprises an incubator 8 and a core holder 7, wherein the core holder 7 is arranged in the incubator 8 and is used for holding a core. Wherein, the core holder 7 is an existing mature product and is not described herein again.

In this embodiment, the upper portion of the core holder 7 is connected to a sealed test gas source 9 through a sealed test pipeline, preferably, the sealed test gas source 9 is a gas cylinder, high-pressure nitrogen is filled in the gas cylinder, and the gas cylinder is used for filling nitrogen into the core holder 7. In other embodiments, other inert gases may be charged into the cylinder.

In this embodiment, the sealing test pipeline is provided with a second pressure control valve 20 to control the output pressure of the sealing test air source 9; the sealing test pipeline is connected with a first measurement pipeline and a first pressure relief pipeline, the first measurement pipeline is provided with a sealing test pressure gauge 10 and a fifth valve 19, and after the fifth valve 19 is opened, the sealing test pressure gauge 10 is used for monitoring the pressure in the rock core holder 7; and a second pressure relief valve 21 is arranged on the first pressure relief pipeline, and after the second pressure relief valve 21 is opened, nitrogen in the core holder 7 is exhausted.

In the embodiment, the lower part of the core holder 7 is connected with a liquid ring pressure pump 11 through a ring pressure pipeline, the liquid ring pressure pump 11 can automatically track confining pressure and quickly maintain a set pressure value, so that the core holder 7 obtains confining pressure; a third pressure control valve 22 is arranged on the annular pressure pipeline, and the third pressure control valve 22 is used for controlling the output pressure of the liquid annular pressure pump 11; and a second pressure relief pipeline is connected to the annular pressure pipeline, a third pressure relief valve 23 is arranged on the second pressure relief pipeline, and after the third pressure relief valve 23 is opened, liquid in the rock core holder 7 flows out. Wherein, liquid ring pressure pump 11 is water ring pressure pump, and the liquid that increases the ring pressure promptly is water, and the water is slightly compressible medium for gas, and pressurization and pressure release are very fast, improve work efficiency.

As shown in fig. 1, the inlet at the left end of the core holder 7 is connected with a displacement gas source 3 through an air inlet pipeline, and preferably, the displacement gas source 3 is a displacement tank. In this embodiment, the six-way valve 6, the first pressure control valve 18 and the fourth valve 16 are arranged on the air inlet pipeline, the six-way valve 6 is connected with a third pressure relief pipeline, a second measurement pipeline, a third measurement pipeline and a branch pipeline, the third pressure relief pipeline is connected with a first pressure relief valve 17, the second measurement pipeline is connected with a second valve 14 and a first displacement pressure gauge 4, and the third measurement pipeline is connected with a third valve 15 and a second displacement pressure gauge 5. Wherein the six-way valve 6 constitutes a multi-way valve. In other embodiments, a branch line may be connected to the outlet line.

In the embodiment, the range of the first displacement pressure gauge 4 is larger than that of the second displacement pressure gauge 5, namely the first displacement pressure gauge 4 is a high-range pressure gauge, the range is 0-10MPa, and the precision is 0.1; the second displacement pressure gauge 5 is a low-range pressure gauge with the range of 0-0.2bar and the precision of 0.05. When the pressure gas higher than 0.2bar is used for testing, the first displacement pressure gauge 4 is used, and when the pressure gas lower than 0.2bar is used for testing, the second displacement pressure gauge 5 is used, so that the pressure can be finely adjusted, a tiny pressure value is measured, and the purposes of preventing the pressure gauge from being damaged by too high pressure and finely metering are achieved.

In this embodiment, first displacement manometer 4 and second displacement manometer 5 are electronic pressure table, and for mechanical pressure table, electronic pressure table's measured value shows in real time, quick reading, and the precision is high, and the calibration zero set is convenient.

In this embodiment, the branch line comprises a first branch line and a second branch line connected in series, a separation bottle 2 is arranged between the first branch line and the second branch line, a first valve 13 is arranged on the second branch line, and the tail end of the first branch line is inserted into the gas detection bottle 1 to detect whether nitrogen is discharged from the branch line when the sealing test gas source 9 fills nitrogen into the core holder 7. Wherein, the gas detection bottle 1 is filled with water, and the separation bottle 2 is an empty bottle.

In this embodiment, the outlet of the right end of the core holder 7 is connected with a gas flow meter 12 through a gas outlet pipeline, and the gas flow meter 12 is used for measuring the gas output. Wherein, a sixth valve 24 is arranged on the air outlet pipeline. Wherein the gas flow meter 12 is a soap film flow meter. In other embodiments, the gas flow meter is a conventional gas flow meter.

In this embodiment, the thermostat 8 has an electric heating tube, which can be heated by an air bath to simulate the real formation temperature, and the thermostat 8 has its internal temperature adjusted by a temperature controller. The upper part, the lower part, the left part and the right part of the constant temperature box 8 are respectively provided with a notch, and each notch is respectively used for a sealing test pipeline, a ring pressure pipeline, an air inlet pipeline and an air outlet pipeline to pass through so as to connect the four pipelines on the core holder 7.

The utility model discloses when carrying out rock stress sensitivity test, mainly include following step:

(1) preparing a core: and measuring parameters such as the diameter and the length of the core, putting the core into a rubber sleeve in the core holder 7 so as to be filled into the core holder 7, connecting pipelines and keeping valves in the device in a closed state.

(2) Sealing with nitrogen gas: opening the first valve 13, the fourth valve 16 and the fifth valve 19, and controlling the second pressure control valve 20 to keep the pressure of the sealing test pressure gauge 10 at 1.5MPa, observing the gas detection bottle 1 at any time in the process, and if bubbles are gradually reduced until the bubbles are not reduced, executing the next operation; and (4) if the air bubbles exist all the time, unloading the rock core, cleaning the rock core holder 7 and the rubber sleeve inside, and executing the step (1) again.

(3) Sealing distilled water: closing the fifth valve 19 and the second pressure control valve 20, opening the liquid annular pressure pump 11 and the third pressure control valve 22, slightly opening the second pressure release valve 21, setting the initial confining pressure of the rock core to be 1.5Mpa, enabling the pumping speed of the liquid annular pressure pump 11 to be about 5ml/min, closing the second pressure release valve 21 until the second pressure release valve 21 discharges water, observing the gas detection bottle 1 and the separation bottle 2 at any time in the process, if the gas detection bottle 1 does not display bubbles, enabling the separation bottle 2 not to display water, executing next step operation, and if bubbles or water is displayed, executing step (1) again.

(4) And (3) testing the permeability: and closing the first valve 13, opening the second valve 14 or the third valve 15 according to the test pressure, adjusting the thermostat 8 to a specified temperature, opening the first pressure control valve 18 and the sixth valve 24, and adjusting the liquid tracking pump 11 after the pressure of the displacement pressure gauge is stable and the temperature of the thermostat 8 is stable so as to gradually increase the confining pressure and further measure the gas flow of the gas flowmeter 12 under different confining pressures in unit time. First pressure control valve 18 is adjusted to measure the amount of gas flowing through gas meter 12 per unit time at different injection pressures.

(5) And (4) finishing the experiment: and closing all valves, closing the constant temperature box 8, opening the second pressure control valve 20 and the third pressure release valve 23 after the temperature is cooled, drying the water in the core holder 7 by using nitrogen, discharging the tested core, and putting the next core in again.

The utility model simulates the formation temperature through the constant temperature box, so that the data is closer to the real environment; moreover, the air tightness of the core holder is tested by using nitrogen, and then the confining pressure is increased by using liquid, so that the pollution of the liquid inlet of the core due to the sealing failure of a rubber sleeve of the core holder is effectively prevented, and the advantages of quick liquid pressurization and pressure relief are achieved; the high-range electronic pressure gauge and the low-range electronic pressure gauge are used for preventing the pressure gauge from being damaged by too high pressure, and the experimental pressure value is measured finely.

The utility model discloses well rock stress sensitivity testing arrangement's embodiment 2:

the present embodiment is different from embodiment 1 in that in embodiment 1, the branch line includes a first branch line and a second branch line connected in series, a separation bottle is provided between the first branch line and the second branch line, and the end of the first branch line is inserted into the gas detection bottle, so that both hermetic sealing and water-tight sealing tests can be performed. In this embodiment, the branch line is a single line, i.e., a separation bottle is not provided, and the end of the branch line is inserted into the gas detection bottle, so that only the gas seal test can be performed.

The utility model discloses well rock stress sensitivity testing arrangement's embodiment 3:

the difference between the embodiment and the embodiment 1 is that in the embodiment 1, a first displacement pressure gauge 4 and a second displacement pressure gauge 5 are connected to the gas inlet pipeline, and the range of the first displacement pressure gauge 4 is larger than that of the second displacement pressure gauge 5. In this embodiment, the intake line is connected to only one displacement pressure gauge.

The utility model discloses well rock stress sensitivity testing arrangement's embodiment 4:

the difference between the present embodiment and embodiment 1 is that, in embodiment 1, both the first displacement pressure gauge 4 and the second displacement pressure gauge 5 are electronic pressure gauges. In this embodiment, the first displacement pressure gauge and the second displacement pressure gauge are both mechanical pressure gauges.

The utility model discloses well rock stress sensitivity testing arrangement's embodiment 5:

the present embodiment is different from embodiment 1 in that, in embodiment 1, the pressurized liquid of the liquid ring pressure pump 11 is water. In this embodiment, the pressurizing liquid of the hydraulic circulating pump is oil.

The above description is only a preferred embodiment of the present application, and not intended to limit the present application, the scope of the present application is defined by the appended claims, and all equivalent structural changes made by using the contents of the specification and the drawings of the present application should be embraced within the scope of the present application.

Claims (10)

1. The rock stress sensitivity testing device is characterized by comprising a constant temperature box (8), wherein a rock core holder (7) for holding a rock core is arranged in the constant temperature box (8); the core holder (7) is connected with a liquid annular pressure pump through an annular pressure pipeline so that the core holder (7) obtains confining pressure; the core holder (7) is connected with a sealing test air source (9) through a sealing test pipeline; the outlet of the core holder (7) is connected with a gas flowmeter (12) through a gas outlet pipeline; the inlet of the core holder (7) is connected with a displacement air source (3) through an air inlet pipeline; the gas inlet pipeline or the gas outlet pipeline is connected with a gas detection bottle (1) through a branch pipeline to detect whether gas is discharged from the branch pipeline when a sealed test gas source (9) fills gas into the core holder (7).

2. The rock stress sensitivity testing device of claim 1, wherein the branch line comprises a first branch line and a second branch line connected in series, and a separation bottle (2) is arranged between the first branch line and the second branch line.

3. The rock stress sensitivity test device according to claim 1 or 2, characterized in that a first displacement pressure gauge (4) and a second displacement pressure gauge (5) are connected to the gas inlet line, and the range of the first displacement pressure gauge (4) is larger than the range of the second displacement pressure gauge (5).

4. The rock stress sensitivity test device according to claim 3, wherein the first displacement pressure gauge (4) and the second displacement pressure gauge (5) are both electronic pressure gauges.

5. The rock stress sensitivity test apparatus according to claim 1 or 2, wherein the liquid annular pressure pump (11) is a water annular pressure pump.

6. The rock stress sensitivity test device of claim 1 or 2, wherein a multi-way valve is arranged on the air inlet pipeline, and the branch pipeline is connected to the multi-way valve.

7. The rock stress sensitivity test device according to claim 1 or 2, wherein a seal test pressure gauge (10) is arranged on the seal test pipeline.

8. The rock stress sensitivity test apparatus according to claim 1 or 2, wherein the seal test gas source (9) is a gas cylinder.

9. The rock stress sensitivity test apparatus of claim 8, wherein the gas cylinder is a nitrogen gas cylinder.

10. A rock stress sensitivity test apparatus according to claim 1 or 2, wherein the gas flow meter (12) is a soap film flow meter.

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