CN111474099A - Rock porosity and specific surface testing device - Google Patents

Abstract

The invention discloses a rock porosity and surface ratio testing device, which belongs to the technical field of oilfield development and testing. The gas chamber I is communicated through the pipeline and the upstream three-way valve. The gas chamber I is connected to one end of the differential pressure sensor, the other end of the differential pressure sensor is connected to the right end of the core holder, and the differential pressure sensor and the core holder pipeline are provided with A pipeline; the right end of the core holder is connected to the airtight container through the pipeline, the downstream three-way valve and the stop valve. The airtight container is provided with a pressure gauge and an exhaust line, and the lower end of the airtight container has a liquid outlet pipeline. There are stop valves and flowmeters in sequence from the bottom. The pipeline at the lower end of the flowmeter extends into the open container. The above connection method constitutes a core ratio test system for measuring the rock ratio; the vacuum pump is installed on the evacuation pipeline, and the evacuation pipeline is installed in the downstream three. Between the through valve and the downstream stop valve.

Description

A rock porosity and surface test device

technical field

The invention belongs to the technical field of oilfield development and testing, and particularly relates to a rock porosity and specific surface testing device.

Background technique

Rock porosity and rock specific surface play an important role in the process of oilfield development, and have important reference and guiding significance for oil exploration. To determine the specific surface of a rock, it is necessary to know the porosity of the corresponding rock, and in the existing testing technology, it is often necessary to have both an experimental instrument for testing the porosity and a testing device for testing the specific surface of the rock. During the test operation, the porosity of the rock must be known before continuing to test the specific value of the corresponding rock. Due to the complexity of the operation, the test efficiency is reduced, and the repeated core removal has a great impact on the test results and reduces the accuracy of the specific value. , resulting in a larger error.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a test device for rock porosity and specific surface, through which the rock core can be installed without repeated disassembly and installation, and the rock can be tested by the opening and closing of the corresponding stop valve and the three-way valve and the work of the vacuum pump. Test the porosity and rock specific surface to obtain the corresponding test data. The test device provided by the present invention can not only complete the test of the core porosity, but also complete the test of the specific surface of the rock at the same time.

The purpose of the present invention is achieved through the following technical solutions:

A device for testing rock porosity and surface ratio, including gas storage cylinder, pipeline, pressure gauge, globe valve, upstream (downstream) three-way valve, one-way valve, upper (lower) gas chamber, core, and core holder , Differential pressure sensor, vacuum pump, flow meter, closed container and open container, etc. According to the drawings in the abstract, it is roughly constituted as follows: the outlet of the gas cylinder has a stop valve (hereinafter referred to as the first stop valve), and a pressure gauge (hereinafter referred to as the first pressure gauge) at the outlet of the stop valve is used to monitor the gas pressure at the outlet end , the front end of the first pressure gauge is provided with a shut-off valve (hereinafter referred to as the second shut-off valve), the front end of the shut-off valve is connected with a check valve through a pipeline, and the front end of the check valve is provided with a lower gas chamber, and the lower gas chamber is connected to the core. The gripper is connected through a pipeline and a shut-off valve (hereinafter referred to as the third shut-off valve), the upper end of the lower gas chamber is provided with the upstream three-way valve, and the upper end of the upstream three-way valve is connected to the upper gas chamber , the upper gas chamber and the differential pressure sensor are connected to the other end of the core holder through a pipeline and the downstream three-way valve, and a pipeline of the upstream three-way valve is connected to a pipeline of the differential pressure sensor. There is a pressure gauge on the pipeline (hereinafter referred to as the second pressure gauge), which is connected in parallel with the differential pressure sensor and the core holder in the figure. The fourth shut-off valve) is connected to the airtight container, and the airtight container is provided with a high-sensitivity pressure gauge (hereinafter referred to as the third pressure gauge) for detecting the pressure in the glass container and a container exhaust shut-off valve. The lower end of the container is connected to the open container through a pipeline with a stop valve (hereinafter referred to as the fifth stop valve) and the flow meter. The test device is provided with a ring pressure pipeline and an evacuation pipeline. The ring pressure pipeline is arranged between the first pressure gauge and the second stop valve and communicates with the ring pressure port of the core holder. A shut-off valve (hereinafter referred to as the sixth shut-off valve), a vacuum pressure gauge (hereinafter referred to as the fourth pressure gauge) and an annular pressure evacuation valve are arranged in the ring pressure pipeline, and the evacuation pipeline is arranged at the downstream three-way valve Between the evacuation pipeline and the fourth shut-off valve, there are an evacuated shut-off valve, a pressure gauge (hereinafter referred to as the fifth pressure gauge) and the vacuum pump.

As option 1, the core porosity test system consists of a lower gas chamber, a pressure gauge (referred to as the sixth pressure gauge), a third shut-off valve, a core holder, a downstream three-way valve, and a pipeline branch and on the branch. It consists of a stop valve (called a branch stop valve), the sixth pressure gauge is directly arranged on the downstream gas chamber to monitor the gas pressure, and the branch stop valve can control the gas to enter the right end of the core holder and penetrate into the core .

As option 2, the rock porosity and surface comparison test device has a data acquisition and processing device.

As a further option 3 of option 2, the data acquisition and processing device is connected with a pressure gauge, a differential pressure sensor, a flow meter, etc. through a data line.

As option 4, the rock porosity and surface ratio test device applies ring pressure to the core holder through a hand pump, that is, the ring pressure circuit is not connected to the main circuit, but is directly connected to the hand pump, and the ring pressure is added. The medium is liquid.

The upper gas chamber and the lower gas chamber described in this patent are only for the schematic diagram provided in this patent, and the upstream and downstream mentioned only refer to the left and right ends of the core holder in the schematic diagram, without any other restrictive meaning.

Beneficial effects of the invention: the effect of simultaneous testing of core porosity and rock specific surface can be achieved, the rock specific surface test can be completed at one time without repeatedly disassembling and installing the core, and the test efficiency and the accuracy of the test results can be effectively improved.

Description of drawings

FIG. 1 is a schematic structural diagram of Embodiment 1. FIG.

FIG. 2 is a schematic structural diagram of Embodiment 2. FIG.

FIG. 3 is a schematic structural diagram of Embodiment 3. FIG.

FIG. 4 is a schematic structural diagram of Embodiment 4. FIG.

In the figure: 1. Gas cylinder; 2-1. First stop valve; 2-2. Sixth stop valve; 2-3. Second stop valve; 2-4. Third stop valve; 2-5. Ring 2-6. Evacuation globe valve; 2-7. Fourth globe valve; 2-8. Exhaust globe valve; 2-9. Fifth globe valve; 2-10. Branch globe valve; 3 -1. The first pressure gauge; 3-2. The second pressure gauge; 3-3. The fourth pressure gauge; 3-4. The fifth pressure gauge; 3-5. The third pressure gauge; 3-6. The sixth Pressure gauge; 4. Check valve; 5. Lower gas chamber; 6. Upstream three-way valve; 7. Upper gas chamber; 8. Core holder; 9. Differential pressure sensor; 10. Downstream three-way valve; 11. Vacuum pump; 12. Closed container; 13. Flow meter; 14. Open container; 15. Data acquisition system.

Detailed ways

The following non-limiting examples serve to illustrate the invention.

Example 1:

As shown in Fig. 1, a rock porosity and surface comparison test device includes a gas storage cylinder 1 for storing the gas medium required for the test, and the outlet end of the gas storage cylinder 1 is connected with a first stop valve 2-1 to open and close Gas, a first pressure gauge 3-1 is installed on the main line between the first cut-off valve 2-1 and the second cut-off valve 2-3 to monitor the gas cylinder outlet pressure. A ring pressure pipeline for applying ring pressure to the core holder 8 is arranged between the stop valves. The ring pressure pipeline is provided with a sixth stop valve 2-2, which is to be close to the fourth pressure gauge 3 of the core holder 8. -3 When the displayed value reaches the predetermined value and remains stable, the sixth cut-off valve 2-2 can be closed (at this time, the annular pressure evacuation valve 2-5 is closed) to maintain the annular pressure value of the core holder 8; the second cut-off valve There is a one-way valve 4 between the valve 2-3 and the lower gas chamber 5. The one-way valve 4 only allows the gas to enter the lower gas chamber 5 in one direction, and the lower gas chamber 5 passes through the pipeline and the third cut-off valve 2-4. Connected with the core holder 8, the upper gas chamber 7 and the lower gas chamber 5 are communicated through an upstream three-way valve, the upper gas chamber 7 and the differential pressure sensor 9 are connected through a pipeline, and the other end of the differential pressure sensor 9 is connected with the downstream three-way valve. 10 is connected by a pipeline, the upstream three-way valve 6 is connected with the pipeline at the other end of the differential pressure sensor 9 (that is, the section connected with the downstream three-way valve 10) through the pipeline, and the left end of the downstream three-way valve 10 is connected with the core holder 8 pipeline. The right end is connected to the fourth cut-off valve 2-7 through a pipeline, and the right end of the fourth cut-off valve 2-7 is connected to a closed container 12 (it can be a closed glass container, etc.) Table 3-5 is used to monitor the gas pressure in the airtight container. At the same time, an exhaust stop valve 2-8 is provided to discharge the gas in the airtight container. The lower end of the airtight container 12 is installed with a liquid outflow pipeline extending into the open container. A fifth stop valve 2-9 and a flow meter 13 are arranged on the pipeline; an evacuation pipeline is arranged on the pipeline between the downstream three-way valve 10 and the fourth stop valve 2-7, and a fifth pressure gauge is arranged on the evacuation pipeline in turn. 3-4. Evacuation shut-off valve 2-6 and vacuum pump 11. The dotted frame in the schematic diagram represents the upper gas chamber region I and the lower gas chamber region II respectively. The volumes of region I and region II are equal, and the volume is set as V ₁ .

Example 2:

As shown in FIG. 2 , this embodiment is basically the same as Embodiment 1, except that the test device is provided with an automatic data acquisition system 15 .

Example 3:

As shown in FIG. 3 , this embodiment is basically the same as Embodiment 1, except that: the lower gas chamber 6 is provided with a sixth pressure gauge 3-6 for monitoring the pressure in the gas chamber, and the lower gas chamber 6 passes through the pipeline- The branch stop valve 2-10-line is connected to the downstream three-way valve 10.

Example 4:

As shown in FIG. 4 , this embodiment is basically the same as Embodiment 3, the difference is that: the test device is provided with an automatic data acquisition system 15 .

Example 5:

The present embodiment is basically the same as the embodiment 1-4, the difference is that: the described one kind of rock porosity, specific surface testing device applies ring pressure to the core holder 8 through a hand pump or the like.

Example 6:

As described in Embodiments 1 and 2, the test method of a rock porosity and ratio test device is as follows:

(1) Test the air tightness of the circuit of the device of the present invention. Open other shut-off valves and three-way valves except the evacuation shut-off valve 2-6 and the fifth shut-off valve 2-9, and check whether there is air leakage when the gas passes through the pipeline.

(2) Evacuate after ensuring that there is no air leakage in the circuit. Close the exhaust stop valve 2-8, the ring pressure exhaust valve 2-5 and the second stop valve 2-3 in turn to apply ring pressure to the core holder through the ring pressure pipeline, wait for the fourth pressure gauge 3-3 When the pressure display value reaches the required ring pressure value, close the sixth stop valve 2-2 and the first stop valve 2-1, first evacuate the circuit for a short time, and close when the second pressure gauge 3-2 is close to zero The vacuum pump 11 then evacuates the core, tightens the knob 10-1 of the downstream three-way valve 10 to block the pipeline connecting the differential pressure sensor, and closes the third stop valve 2-4 and the fourth stop valve 2-7 at the same time, Start the vacuum pump 11, start to evacuate the core, and close the evacuation shut-off valve 2-6 when the value of the fourth pressure gauge 3-4 is stable.

(3) Measure the core porosity. After the evacuation is completed, firstly tighten the knob 10-2 of the downstream three-way valve 10, loosen the knob 10-1, tighten the knob 6-2 of the upstream three-way valve 6, open the first stop valve 2-1 and The second cut-off valve 2-3 is filled with detection gas in the lower gas chamber 5 and the upper gas chamber 7. When the value displayed on the differential pressure sensor is stable, it is P ₁ (this value is not used as a calculated value), and the first cut-off valve 2 is closed. -1. The second shut-off valve 2-3, tighten the knob 6-1 of the upstream three-way valve 6 to block and separate the areas of the two gas chambers. It is known from common sense that the gas pressure is still P after the two areas are blocked and separated. ₁ ; Then, open the third stop valve 2-4, loosen the knob 6-2 of the upstream three-way valve 6, loosen the knob 10-1 of the downstream three-way valve 10, and record after the displayed value on the differential pressure sensor is stable. The value is P ₂ , the pressure value on the second pressure gauge 3-2 is P ₃ , and the volume of the pipeline in the porosity test system except for zone I and zone II is V ₂ , according to the principle of gas measurement porosity can be obtained. Measured core porosity:

In the formula: V _p =(P ₂ /P ₃ )V ₁ -V ₂

Among them: V _p is the core pore volume; P ₂ is the reading of the differential pressure sensor; P ₃ is the reading of the second pressure gauge; V ₁ is the volume of the area II; V ₂ is the pipeline volume of the porosity test system except the area I and area II .

(4) Measure the rock surface. After measuring the core porosity, loosen the knobs 6-1, 6-2 and 10-2, open the evacuation shut-off valve 2-6, and start the vacuum pump to extract the gas in the circuit until the second pressure gauge 3-2 shows zero value. or close to zero, turn off the vacuum pump, tighten knobs 6-1, 6-2 and 10-1, close the evacuation shut-off valve 2-6; open the first shut-off valve 2-1, the second shut-off valve 2-3, the The fourth stop valve 2-7 and the fifth stop valve 2-9, the gas enters the core from the left end of the core and is displaced, observe the liquid outflow of the liquid outlet pipeline and the stability of the flow meter indication value, and read the first when the liquid flows out stably and continuously. Three pressure gauges 3-5 read P ₀₀ and flow meter 13 read Q ₁ , according to the measured core porosity and the known required parameters, the specific value can be obtained:

In the formula: S _b1 - rock ratio surface;

—岩石孔隙度；

- rock porosity;

A—core cross-sectional area;

L—core length;

P₀为室内压力；H—pressure difference at both ends of the core, calculation formula

P ₀ is the indoor pressure;

Q ₁ — air flow through the core;

μ—air viscosity.

The core porosity value and the rock specific surface value mentioned above can also be obtained through data processing by the data acquisition system 15 described in the present invention.

Example 7:

As described in Examples 3 and 4, the test method of a rock porosity and a specific surface test device is carried out according to the following steps:

(1) Test the air tightness of the circuit of the device of the present invention. Open other shut-off valves except the evacuation shut-off valve 2-6, the fifth shut-off valve 2-9 and the downstream three-way valve 10 to check whether there is gas leakage when the gas passes through the pipeline.

(2) Evacuate after ensuring that there is no air leakage in the circuit. Close the exhaust stop valve 2-8, the ring pressure exhaust valve 2-5 and the second stop valve 2-3 in turn to apply ring pressure to the core holder through the ring pressure pipeline, wait for the fourth pressure gauge 3-3 When the pressure display value reaches the required ring pressure value, close the sixth stop valve 2-2 and the first stop valve 2-1, first evacuate the circuit for a short time, and close when the sixth pressure gauge 3-6 is close to zero Vacuum pump 11; then vacuumize the core, tighten the knob 10-1 of the downstream three-way valve 10, close the third stop valve 2-4 and the fourth stop valve 2-7 at the same time, start the vacuum pump 11, and start vacuuming the core , when the value of the fourth pressure gauge 3-4 stabilizes and reaches a certain vacuum value, turn off the vacuum pump 11 and the evacuation cut-off valve 2-6.

(3) Measure the core porosity. After the evacuation is completed, firstly tighten the knob 10-2 of the downstream three-way valve 10, close the branch stop valve 2-10, loosen the knob 10-1, and open the first stop valve 2-1 and the second stop valve 2 -3 Fill the downward gas chamber 5 with the detection gas, record the first pressure value P ₃ when the value of the sixth pressure gauge is stable, and close the first shut-off valve 2-1 and the second shut-off valve 2-3; then, open the The third cut-off valve 2-4 and the sixth cut-off valve 2-10, record the second pressure value P ₄ when the value of the sixth pressure gauge is stable. In Embodiments 3 and 4, the volume of the area II is V _1. The pipeline volume of the porosity test system except for area II is V ₃ , then the measured core porosity can be obtained according to the principle of gas measurement:

where:

Among them: V _p is the core pore volume; P ₃ is the first pressure value recorded; P ₄ is the second pressure value recorded; V ₁ is the volume of the area II; V ₃ is the volume of the pipeline of the porosity test system except for the area II .

(4) Measure the rock surface. After measuring the core porosity, loosen the knob 10-2, open the evacuation shut-off valve 2-6, start the vacuum pump to extract the gas in the circuit until the sixth pressure gauge 3-6 shows zero or close to zero, and shut down the vacuum pump , tighten the knob 10-1 and close the branch shut-off valve 2-10, close the evacuation shut-off valve 2-6; open the first shut-off valve 2-1, the second shut-off valve 2-3, the fourth shut-off valve 2-7 and The fifth stop valve 2-9, the gas enters the core from the left end of the core for displacement, observe the liquid outflow of the liquid outlet pipeline and the stability of the indicated value of the flowmeter, and read the reading of the third pressure gauge 3-5 when the liquid flows out stably and continuously P ₀₁ and the reading Q ₂ of the flow meter 13, according to the measured core porosity and the known required parameters, the specific value can be obtained:

In the formula: S _b1 - rock ratio surface;

—岩石孔隙度；

- rock porosity;

A—core cross-sectional area;

L—core length;

P₀为室内压力；H—pressure difference at both ends of the core, calculation formula

P ₀ is the indoor pressure;

Q ₂ — air flow through the core;

μ—air viscosity.

The core porosity value and the rock specific surface value mentioned above can also be obtained through data processing by the data acquisition system 15 described in the present invention.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (7)

1. a rock porosity, a surface comparison test device, is characterized in that: comprise a porosity test system, a surface comparison test system, and the porosity test system consists of a gas cylinder 1, a one-way valve 4, a lower gas chamber 5, The upstream three-way valve 6, the upper gas chamber 7, the core holder 8, the differential pressure sensor 9, the downstream three-way valve 10, the vacuum pump 11 and the pressure gauge and the stop valve on each connecting pipeline are composed; the surface test system consists of Gas cylinder 1, one-way valve 4, lower gas chamber 5, upstream three-way valve 6, core holder 8, downstream three-way valve 10, vacuum pump 11, flow meter 13, closed container 12, open container 14 and corresponding connections It consists of a pressure gauge and a shut-off valve on the pipeline. 2. The rock porosity and specific surface testing device according to claim 1, characterized in that: the porosity testing system consists of a gas storage cylinder 1, a one-way valve 4, a lower gas chamber 5, a core holder 8, The downstream three-way valve 10, the vacuum pump 11, the pipeline connecting the lower gas chamber 5 and the downstream three-way valve 10, and the pressure gauge and the stop valve on the corresponding connecting pipeline are composed; Valve 4, lower gas chamber 5, core holder 8, downstream three-way valve 10, vacuum pump 11, flow meter 13, closed container 12, open container 14, pressure gauge and stop valve on the corresponding connecting pipeline. 3. The rock porosity and specific surface testing device according to claim 1 or 2, characterized in that: the core holder 8, the third pressure gauge 3-3, the ring pressure evacuation valve 2-5, the third pressure gauge 3-3, the The six stop valves 2-2 and pipelines form a ring pressure pipeline, and the high pressure gas provided in the gas storage bottle 1 applies ring pressure to the core holder 8 . 4 . The rock porosity and surface ratio testing device according to claim 1 or 2 , wherein the ring pressure adding pipeline is directly connected to the hand pump to add ring pressure. 5 . 5. The rock porosity and surface ratio testing device according to claim 1 or 2, wherein the vacuum pump 11, the evacuation shut-off valve 2-6 and the fifth pressure gauge 3-4 form an evacuation pipeline, and the The evacuation line is used to evacuate all remaining gas in the line and to evacuate the core. 6 . The rock porosity and specific surface testing device according to claim 1 or 2 , wherein the testing device is provided with a data acquisition system 15 . 7 . 7. The rock porosity and surface ratio testing device according to claim 1 or 2, characterized in that: the upper part of the airtight container 12 is provided with a third pressure gauge 3-5 and an exhaust shut-off valve 2-8. The third pressure gauge 3-5 is a high-sensitivity pressure gauge.

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