A device for measuring the pore pressure conductivity of medium and high rank coal core matrix

Abstract

The present invention provides a device for measuring the matrix pore pressure conductivity of medium- and high-rank coal cores, comprising a helium cylinder, a methane cylinder, an annular pressure container, and a high-pressure test chamber. The helium cylinder and the methane cylinder are each connected to one end of a volume reference cylinder, a desorption tank, or a piston container, and the other ends of the volume reference cylinder, the desorption tank, and the piston container are each connected to a booster pump. One end of the annular pressure container is respectively connected to the helium cylinder, the methane cylinder, and the high-pressure test chamber input end, and the other end of the annular pressure container is connected to the high-pressure test chamber output end. The helium cylinder and the methane cylinder are both connected to the high-pressure test chamber input port, the high-pressure test chamber output port is connected to the volume calibration container input port, and the volume calibration container output port is respectively connected to the volume reference cylinder, the desorption tank, and the piston container. The high-pressure test chamber includes sealed end caps at both ends and a high-pressure test chamber disposed between the sealed end caps. A sleeve is disposed within the high-pressure test chamber, and a core is disposed within the sleeve. The conductivity measuring device of the present invention provides a theoretical basis for the formulation of medium- and high-rank coalbed methane solutions.

Description

Technical Field

[0001] The present invention relates to the technical field of conductivity measuring devices, in particular to a device for measuring the pore pressure conductivity of a medium- and high-rank coal core matrix. Background Art

[0002] The efficient and economical extraction of medium- and high-rank coalbed methane, in addition to being significantly affected by three external factors: drilling and completion technology, well type control technology, and drainage and production technology, also depends on whether efficient production blocks can be screened out from numerous coalbed methane-bearing areas to meet the principle of economical and efficient production. The production capacity of efficient production blocks depends not only on many coalbed methane reserve parameters, but also on whether coalbed methane can be quickly and efficiently desorbed, diffused, and migrated from the adsorbed state on the surface of matrix pores (accounting for more than 75% of coalbed methane reserves) to the interconnected cleats and fractures, and then quickly enriched in the high-permeability areas of the wellbore to form large-scale gas production and high efficiency. When the gas content per ton of coal in coalbed methane reservoirs is the same or the reserves in the blocks are the same, the production rate and scale enrichment efficiency vary greatly. It is often the case that gas cannot be produced or the production does not meet the standards, resulting in wasted investment. This poses a huge challenge to the efficient and economical production of coalbed methane. It is of great significance to rationally select efficient enrichment and production blocks when the reserves and resources are determined.

[0003] The core matrix pore pressure conductivity rate experimental device is used to compare the pressure conductivity rate of coalbed methane in the core matrix pores of coal reservoirs of different coal ranks or blocks under a certain pressure, providing the necessary technical basis for the optimization of parameters for efficient enrichment and production of coalbed methane. There is no experimental device for testing the core matrix pore pressure conductivity rate in the existing technology. Summary of the Invention

[0004] The purpose of the present invention is to overcome and supplement the deficiencies in the prior art by providing a device for measuring the pore pressure conductivity of medium- and high-rank coal cores, thereby providing the necessary technical basis for optimizing parameters for efficient coalbed methane enrichment and production. The technical solution of the present invention is as follows:

[0005] A device for measuring the pore pressure conductivity of a medium- and high-rank coal core matrix, comprising: a helium cylinder, a methane cylinder, an annular pressure container, and a high-pressure test chamber, wherein the helium cylinder and the methane cylinder are connected to one end of a volume reference cylinder, a desorption tank, or a piston container, and the other ends of the volume reference cylinder, the desorption tank, and the piston container are connected to a booster pump, one end of the annular pressure container is connected to the helium cylinder, the methane cylinder, and the input end of the high-pressure test chamber respectively, and the other end of the annular pressure container is connected to the output end of the high-pressure test chamber, the helium cylinder and the methane cylinder are connected to the input port of the high-pressure test chamber, and the output port of the high-pressure test chamber is connected to the The input port of the volume correction container is connected, and the output port of the volume correction container is respectively connected to the volume reference cylinder, the analytical tank and the piston container; the high-pressure experimental chamber includes sealed end covers at both ends and a high-pressure experimental chamber arranged between the sealed end covers, a sleeve is arranged in the high-pressure experimental chamber, a core is arranged in the sleeve, a plurality of collection holes are arranged on the sleeve, each of the collection holes is provided with a pipeline, each of the pipelines is connected to a pressure sensor, the input end and the output end of the high-pressure experimental chamber are also connected to a pressure differential sensor through a pipeline, and the pressure sensor and the pressure differential sensor are both connected to an electric control cabinet.

[0006] Preferably, in the medium- and high-rank coal core matrix pore pressure conductivity measuring device, five collection holes are arranged at intervals on the sleeve.

[0007] Preferably, in the medium- and high-rank coal core matrix pore pressure conductivity measuring device, both ends of the sleeve are sealed by a plug and a sealing ring.

[0008] Preferably, the medium- and high-rank coal core matrix pore pressure conductivity measuring device, wherein: an exhaust port is provided at the top of the high-pressure test chamber, and a drain port is provided at the bottom of the high-pressure test chamber; an internal pressure inlet and an internal pressure outlet are respectively provided on the sealing end covers at both ends of the high-pressure test chamber, and an internal pressure inlet hole and an internal pressure outlet hole are respectively provided at both ends of the sleeve; the output end of the high-pressure test chamber is also connected to a photoelectric bubble detector, and the photoelectric bubble detector is connected to an electric control cabinet.

[0009] Preferably, the medium- and high-rank coal core matrix pore pressure conductivity measuring device is configured such that: pressure sensors are provided on the volume reference cylinder, the analytical tank, the piston container, the volume correction container and the booster pump, and the pressure sensors are connected to the electrical control cabinet.

[0010] Preferably, in the medium- and high-rank coal core matrix pore pressure conductivity measuring device, temperature sensors are provided on the volume reference cylinder, the analytical tank, and the volume correction container, and the temperature sensors are connected to the electric control cabinet.

[0011] Preferably, the medium- and high-rank coal core matrix pore pressure conductivity measuring device is provided, wherein: a first valve and a second valve are provided between the helium cylinder and the methane cylinder, a third valve and a fourth valve are provided on the pipeline connecting the annular pressure container and the high-pressure test chamber, a fifth valve, a sixth valve, a seventh valve, an eighth valve and a ninth valve are provided on the pipeline between the collection hole and the pressure sensor, and a tenth valve, an eleventh valve and a twelfth valve are provided on the pipeline connecting the input end and the output end of the high-pressure test chamber.

[0012] Preferably, the medium- and high-rank coal core matrix pore pressure conductivity measuring device is provided, wherein: a thirteenth valve, a fourteenth valve, and a fifteenth valve are provided on the pipeline connecting the helium cylinder and the methane cylinder to the input port of the high-pressure experimental chamber, a sixteenth valve is provided on the pipeline connecting the high-pressure experimental chamber and the photoelectric bubble detector, and a seventeenth valve and an eighteenth valve are provided on the pipeline connecting the high-pressure experimental chamber and the volume correction container.

[0013] Preferably, the medium- and high-rank coal core matrix pore pressure conductivity measuring device is provided, wherein: a nineteenth valve is provided on the pipeline connecting the output port of the volume correction container to the volume reference cylinder, the analytical tank and the piston container; a twentieth valve, a twenty-first valve, a twenty-second valve and a twenty-third valve are provided on the pipeline connecting the volume reference cylinder, the analytical tank and the piston container to the booster pump; and a twenty-fourth valve, a twenty-fifth valve and a twenty-sixth valve are further provided on the pipeline connecting the helium cylinder and the methane cylinder to the volume reference cylinder, the analytical tank or the piston container.

[0014] Preferably, the medium- and high-rank coal core matrix pore pressure conductivity measuring device, wherein: the pipeline of the collection hole is provided with pressure sensors, including a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, and a fifth pressure sensor; a sixth pressure sensor, a seventh pressure sensor, and an eighth pressure sensor are provided on the pipeline connecting the helium cylinder and the methane cylinder to the volume reference cylinder, the analytical tank or the piston container; and a ninth pressure sensor is provided on the pipeline of the booster pump outlet.

[0015] Preferably, the medium- and high-rank coal core matrix pore pressure conductivity measuring device is provided, wherein: the inlet and outlet of the high-pressure test chamber are respectively provided with a tenth pressure sensor and an eleventh pressure sensor, and the exhaust port of the high-pressure test chamber is provided with a twelfth pressure sensor.

[0016] Advantages of the present invention:

[0017] The medium and high rank coal core matrix pore pressure conductivity measuring device of the present invention can measure the key evaluation indicators related to the physical parameter characteristics of the coal rock itself, such as the pressure propagation rate and coalbed methane desorption rate in the porous medium of the medium and high rank coalbed methane coal seam core. The measured parameters are closely related to the production and mining efficiency evaluation of the coalbed methane reservoir block. The measured parameters of the device can be used to establish the correspondence between the gas production capacity of different coalbed methane reservoir blocks and the physical properties of the coal reservoir rock, and thereby screen high-efficiency production blocks, providing a theoretical basis for the formulation of economical, reasonable and efficient development plans for medium and high rank coalbed methane. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the device for measuring the pore pressure conductivity rate of the high-rank coal core matrix of the present invention.

[0019] Figure 2 for Figure 1 Schematic diagram of the structure of the medium and high pressure experimental chamber.

[0020] Figure 3 Schematic diagram of circuit connection of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0022] Example 1:

[0023] like Figures 1-2 As shown: The present invention provides a device for measuring the pore pressure conductivity of the medium and high rank coal core matrix, which is characterized by comprising a helium cylinder 1, a methane cylinder 2, an annular pressure container 3 and a high-pressure experimental chamber 4, wherein the helium cylinder 1 and the methane cylinder 2 are connected to one end of a volume reference cylinder 5, a desorption tank 6 or a piston container 7, and the other ends of the volume reference cylinder 5, the desorption tank 6 and the piston container 7 are connected to a booster pump 8, one end of the annular pressure container 3 is respectively connected to the input end of the helium cylinder 1, the methane cylinder 2 and the high-pressure experimental chamber 4, and the other end of the annular pressure container 3 is connected to the output end of the high-pressure experimental chamber 4, the helium cylinder 1 and the methane cylinder 2 are connected to the input port of the high-pressure experimental chamber 4, and the output port of the high-pressure experimental chamber 4 is connected to The input port of the volume correction container 9 and the output port of the volume correction container 9 are respectively connected to the volume reference cylinder 5, the analytical tank 6 and the piston container 7; the high-pressure experimental chamber 4 includes sealed end covers 41 at both ends and a high-pressure experimental chamber 42 arranged between the sealed end covers, a sleeve 43 is arranged in the high-pressure experimental chamber 42, a core 44 is arranged in the sleeve 43, a plurality of collection holes 45 are arranged on the sleeve 43, each of the collection holes 45 is provided with a pipeline 46, each of the pipelines 46 is connected to a pressure sensor, the input and output ends of the high-pressure experimental chamber 4 are also connected to a pressure differential sensor 48 through wires, and the pressure sensor and the pressure differential sensor 48 are both connected to the electric control cabinet 10.

[0024] Wherein: five collecting holes 45 are arranged at intervals on the sleeve.

[0025] Wherein: both ends of the sleeve 43 are sealed by plugs 49 and sealing rings 50.

[0026] Wherein: the top end of the high pressure test chamber 4 is provided with an exhaust port 92 , and the bottom end of the high pressure test chamber 4 is provided with a liquid discharge port 93 .

[0027] The output end of the high-voltage test chamber 4 is further connected to a photoelectric bubble detector 11 , and the photoelectric bubble detector 11 is connected to an electric control cabinet 10 .

[0028] Wherein: pressure sensors are provided on the volume reference cylinder 5 , the analytical tank 6 , the piston container 7 , the volume calibration container 9 and the booster pump 8 , and the pressure sensors are connected to the electric control cabinet 10 .

[0029] Wherein: the volume reference cylinder 5 , the analytical tank 6 , and the volume calibration container 9 are all provided with temperature sensors, and the temperature sensors are connected to the electric control cabinet 10 .

[0030] The sealed end caps 41 at both ends of the high-pressure test chamber 4 are respectively provided with an internal pressure inlet 94 and an internal pressure outlet 95, and the ends of the sleeve are respectively provided with an internal pressure inlet hole 96 and an internal pressure outlet hole 97. The sleeve is provided with five sampling holes, a loose plug, an internal pressure inlet, and an internal pressure outlet at intervals. These are all connected to a pressure sensor and a differential pressure sensor via retractable spiral pressure lines installed at the input and output ports of the high-pressure test chamber.

[0031] Among them: a first valve 51 and a second valve 52 are set between the helium cylinder and the methane cylinder, a third valve 53 and a fourth valve 54 are set on the pipeline connecting the annular pressure container and the high-pressure test chamber, a fifth valve 55, a sixth valve 56, a seventh valve 57, an eighth valve 58 and a ninth valve 59 are set on the pipeline between the collection hole and the pressure sensor, and a tenth valve 60, an eleventh valve 61 and a twelfth valve 62 are set on the pipeline connecting the input end and the output end of the high-pressure test chamber.

[0032] Wherein: a thirteenth valve 63, a fourteenth valve 64 and a fifteenth valve 65 are provided on the pipelines connecting the helium cylinder and the methane cylinder to the input port of the high-pressure experimental chamber; a sixteenth valve 66 is provided on the pipeline connecting the high-pressure experimental chamber and the photoelectric bubble detector; a seventeenth valve 67 and an eighteenth valve 68 are provided on the pipeline connecting the high-pressure experimental chamber and the volume calibration container.

[0033] Among them: a nineteenth valve 69 is provided on the pipeline connecting the output port of the volume correction container to the volume reference cylinder, the analytical tank and the piston container; a twentieth valve 70, a twenty-first valve 71, a twenty-second valve 72 and a twenty-third valve 73 are provided on the pipeline connecting the volume reference cylinder, the analytical tank and the piston container to the booster pump; a twenty-fourth valve 74, a twenty-fifth valve 75 and a twenty-sixth valve 76 are also provided on the pipeline connecting the helium cylinder and the methane cylinder to the volume reference cylinder, the analytical tank or the piston container.

[0034] Among them: pressure sensors are set on the pipeline of the collection hole, including the first pressure sensor 81, the second pressure sensor 82, the third pressure sensor 83, the fourth pressure sensor 84, and the fifth pressure sensor 85. The sixth pressure sensor 86, the seventh pressure sensor 87, and the eighth pressure sensor 88 are set on the pipeline connecting the helium cylinder and the methane cylinder to the volume reference cylinder, the analytical tank or the piston container. The ninth pressure sensor 47 is set on the pipeline of the booster pump outlet.

[0035] The inlet and outlet of the high-pressure test chamber are respectively provided with a tenth pressure sensor 89 and an eleventh pressure sensor 90 , and the exhaust port of the high-pressure test chamber is provided with a twelfth pressure sensor 91 , which is a ring pressure sensor.

[0036] like Figure 3 As shown: the electric control cabinet is connected to the first valve 51, the second valve 52, the third valve 53, the fourth valve 54, the fifth valve 55, the sixth valve 56, the seventh valve 57, the eighth valve 58, the ninth valve 59, the tenth valve 60, the eleventh valve 61, the twelfth valve 62, the thirteenth valve 63, the fourteenth valve 64, the fifteenth valve 65, the sixteenth valve 66, the seventeenth valve 67, the eighteenth valve 68, the nineteenth valve 69, the twentieth valve 70, the twenty-first valve 71, the twenty-second valve 72, the twenty-third valve 73, the twenty-fourth valve 74, the twenty-fifth valve 75, the twenty-sixth valve 76 6. Connect the first pressure sensor 81, the second pressure sensor 82, the third pressure sensor 83, the fourth pressure sensor 84, the fifth pressure sensor 85, the sixth pressure sensor 86, the seventh pressure sensor 87, the eighth pressure sensor 88, the ninth pressure sensor 47, the tenth pressure sensor 89, the eleventh pressure sensor 90, the twelfth pressure sensor 91, the photoelectric bubble detector, the volume reference cylinder temperature sensor, the analytical tank temperature sensor, the volume calibration container temperature sensor, the high-pressure experimental chamber temperature sensor, the booster pump, the vacuum pump, and the constant temperature box.

[0037] The electric control cabinet is controlled by PLC, which is Siemens CPU SR30 AC / DC / RAL, model 6ES7 288-1SR30-0AA0.

[0038] Valves 1 to 26

[0039] First valve: Helium cylinder on / off valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0040] Second valve: methane gas on-off valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0041] Third valve: Annular pressure vessel booster inlet valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0042] Fourth valve: High-pressure test chamber sealing isolation valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0043] Fifth valve: Overpressure protection valve for the first segment pressure tap of the sleeve, direct-acting two-position straight-through solenoid valve (NO), normally closed valve, 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0°C ~ +200°C / DC24V / 0.05-70MPa);

[0044] Sixth valve: Overpressure protection valve for the second segment pressure tap of the sleeve, direct-acting two-position straight-through solenoid valve (NO), normally closed valve, 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0°C ~ +200°C / DC24V / 0.05-70MPa);

[0045] Valve 7: Overpressure protection valve for the third section pressure tap of the sleeve, direct-acting two-position straight-through solenoid valve (NO), normally closed valve, 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0°C ~ +200°C / DC24V / 0.05-70MPa);

[0046] Eighth valve: Overpressure protection valve for the fourth section pressure tap of the sleeve, direct-acting two-position straight-through solenoid valve (NO), normally closed valve, 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0°C to +200°C / DC24V / 0.05-70MPa)

[0047] Ninth valve: Overpressure protection valve for the fifth section pressure tap of the sleeve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0048] Valve 10: Isolation valve between the high-pressure test chamber internal pressure inlet and the differential pressure sensor, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXIIBT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0049] Valve 11: Bypass valve at both ends of the differential pressure sensor, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa)

[0050] Valve 12: Isolation valve between the pressure outlet of the high-pressure test chamber and the differential pressure sensor, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0051] Thirteenth valve: Inlet end evacuation solenoid valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0052] Valve 14: Annular pressure booster gas-liquid isolation valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0053] Fifteenth valve: Sleeve internal pressure injection main valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa)

[0054] Sixteenth valve: Bubble detector air inlet switch valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa),

[0055] Valve 17: High-pressure test chamber sleeve internal pressure outlet evacuation valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0056] 18th valve: calibration container air inlet on-off valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0057] Valve 19: Calibration vessel bottom outlet valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0058] Valve 20: Volume reference cylinder boost switch valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0059] Valve 21: Degassing tank boost on / off valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0060] Valve 22: Piston container booster on-off valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0061] Valve 23: Booster pump head exhaust switch valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0062] Valve 24: Volume reference cylinder intake and exhaust switching valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0063] Valve 25: Degassing tank air inlet and exhaust switching valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa);

[0064] Valve 26: Piston container gas-liquid isolation valve, direct-acting two-position straight-through solenoid valve NO, normally closed valve 316L stainless steel, model LIPDG-D3mm (EXII BT4 / 0℃~+200℃ / DC24V / 0.05-70MPa).

[0065] First to twelfth pressure sensors

[0066] The first pressure sensor: a pressure sensor with a segmented pressure measuring hole in the sleeve, model OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0067] Second pressure sensor: Sleeve segmented pressure measuring hole one pressure sensor, model OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0068] The third pressure sensor: a pressure sensor of the sleeve segmented pressure measuring hole, model OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0069] The fourth pressure sensor: a pressure sensor of the sleeve segmented pressure measuring hole, model OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0070] The fifth pressure sensor: a pressure sensor for the sleeve segmented pressure measuring hole, model OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0071] Sixth pressure sensor: volume reference cylinder pressure sensor, OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0072] Seventh pressure sensor: analytical tank pressure sensor, OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0073] Eighth pressure sensor: piston container pressure sensor, OMEGA high-precision pressure sensor, model PX409-3.5KGI;

[0074] Ninth pressure sensor: Booster pump pressure sensor, OMEGA high-precision pressure sensor, model PX409-3.5KGI.

[0075] Tenth pressure sensor: OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0076] Eleventh pressure sensor: OMEGA high-precision pressure sensor, model PX409-1.5KGI;

[0077] 12th pressure sensor: OMEGA high-precision pressure sensor, model PX409-2.5KGI;

[0078] Booster pump: Model QUIZIX Q5210-HC-A-AH.

[0079] The differential pressure sensor is a differential pressure sensor at both ends of the high-pressure experimental chamber, and the Honeywell analog static pressure sensor is a high-precision differential pressure transmitter, model DPT2500U1-A.

[0080] Photoelectric bubble detector, model CMG-ZLM-MSJS-LAN (FU-JS360-002).

[0081] Temperature sensors are set in the volume reference cylinder, the analytical tank, the volume calibration container, and the high-pressure experimental chamber temperature sensor.

[0082] Volume reference cylinder temperature sensor: Model AZ8821 (platinum resistance 0.01℃ high-precision PT100 thermometer -100~300℃ resistance probe sensor, needle length 15CM;

[0083] Desorption tank temperature sensor: Model AZ8821 (platinum resistance 0.01℃ high precision PT100 / -100~300℃ resistance probe sensor needle length 15CM);

[0084] Volume calibration container temperature sensor: Model AZ8821 (platinum resistance 0.01℃ high precision PT100 / -100~300℃ resistance probe sensor needle length 15CM);

[0085] High-pressure test chamber temperature sensor: Model AZ8821 (platinum resistor 0.01℃ high-precision PT100 / -100~300℃ resistance probe sensor needle length 15CM).

[0086] Vacuum pump: Model Turbo TM 1100.

[0087] The upstream gas state parameter acquisition unit consists of a helium cylinder, a methane cylinder, a fixed volume standard tank; a volume reference cylinder, an annular pressure container, a booster pump and a pressure, temperature and volume state parameter acquisition module, realizing the real-time measurement function of the gas standard volume under different temperature and pressure conditions.

[0088] The high-pressure experimental chamber includes a sealing end cover and a high-pressure experimental chamber. The gas injection pipeline entering the high-pressure experimental chamber is a metal hard pipe. The metal hard pipe and the sealing end covers at both ends are designed for dynamic sealing. After entering the high-pressure experimental chamber, the gas injection pressure pipeline and the gas production pipeline are fixedly sealed and connected to the live plug in the sleeve. The high-pressure experimental chamber is composed of a high-temperature and high-pressure fluororubber sample sleeve, and the core is loaded in the sleeve. The two ends of the sleeve are sealed with live plugs, and the live plug and the pipeline are fixedly sealed, thereby realizing the simultaneous loading and deformation tracking of the axial and radial pressures of the sample in the sample sleeve under different pressures and pressures, so as to realize the physical process simulation of the formation conditions.

[0089] The sleeve is made of fluororubber, and 5 pressure collection holes are evenly designed on the fluororubber sleeve, or the number can be increased or decreased as needed. The collection holes are sealed with the sample sleeve through a high-pressure resistant flexible metal pipeline and then pass through the end cover of the outer high-pressure experimental chamber, and are sealed with the high-pressure experimental chamber and the high-pressure metal pipeline through high-pressure packing. The middle section adopts a multi-turn spiral design to ensure that the metal pipeline in the annular space between the high-pressure experimental chamber and the fluororubber sleeve is within the axial and radial flexible deformation range allowed by the design and experiment without affecting the reliability of its high-pressure seal, thereby meeting the dynamic simulation and deformation needs of the formation conditions of the coal and rock samples in the high-pressure sleeve.

[0090] A digital precision pressure sensor required for different experimental pressures is connected to each collection hole in the outer high-pressure experimental chamber, and a timer is started synchronously. A pressure differential sensor is installed at the inlet and outlet ends to realize the precise real-time measurement and collection of pressure differentials. The entire process uses self-controlled solenoid valves and pipelines to connect various devices, and the electric control cabinet and touch screen control operation realize automatic control and calculation functions.

[0091] The experimental device is equipped with an outlet volume meter and a photoelectric bubble detector. A reversing solenoid valve is installed at the outlet of the high-pressure sleeve or plug metal pipeline. The volume correction container and the photoelectric bubble detector realize the accurate measurement of the output gas and rate and the dynamic observation of the pressure propagation rate at the outlet.

[0092] The state parameter acquisition unit in this device is designed and equipped with precision pressure sensors and temperature sensors, and includes a precisely calibrated gas volume reference cylinder and a gas desorption tank. The data acquisition module can display the standard volume of gas in the reference cylinder in real time. The reference cylinder can measure the standard volume of gas entering the porous medium of the core model.

[0093] Example 2: Helium pressure conductivity test

[0094] The main unit of the process is composed of a high-pressure experimental chamber for the static pressure triaxial segmented precision pressure measurement sample experiment, a fluororubber sleeve for triaxial stress environment segmented pressure collection, and an experimental device outlet volume metering and bubble photoelectric detection unit. In addition, the auxiliary units include a helium cylinder, a coalbed methane (CH4) container, a pressure transmission container, a piston pressure pump, a constant temperature box, a vacuum pump, a microcomputer, etc., which form a complete experimental system to carry out relevant physical simulation tests such as the pressure conduction rate of medium and high coal rank coalbed methane. The experimental and equilibrium rate pressures are determined according to the overburden pressure porosity test, which is generally 8MPa, the closure pressure of the coal rock cleat fissure. At this time, only the matrix pores serve as gas transmission channels, which can reflect the basic characteristics of the matrix pore adsorption and desorption capacity and the potential characteristic parameters of coalbed methane adsorption and desorption.

[0095] Sampling design: Drill cylindrical (Y representative) samples (25mm×50mm or other corresponding specifications) from the J area (J representative), the Chang area (C representative), and the An area (A representative) coal reservoir, 5 pieces each, for a total of 15 pieces (composed of three groups of long cores, each group is an experimental sample). First, use the water injection method to accurately calibrate the volume reference cylinder, each section of the pipeline and the pressure sensor cavity to obtain blank dead bodies and correction values.

[0096] Helium pressure conductivity test process, steps and preparations: First, use a conventional porosimeter to measure the porosity, then use AP608 (500psi) to measure the permeability, then assemble a group of medium and high-rank coal columnar cores, close the 15th valve at the inlet end of the core holder, evacuate from the outlet end for 24 hours, and simultaneously evacuate the volume calibration container for 24 hours; Helium equilibrium conductivity experiment: Close the second valve of methane and the third valve of the annular pressure container pipeline → close the 15th valve at the inlet end of the core → open the 24th valve between the helium and reference cylinders to allow helium to fill the reference cylinder, open the pressure tracking pump connected to the reference cylinder to maintain a pressure of 8MPa → close the 20th valve connected to the helium Four valves → prepare six stopwatches or trigger the HMI virtual synchronization start timer → instantaneously open the fourteenth and fifteenth valves on the core holder to allow helium to enter the core. At the same time, each timer corresponds to the differential pressure sensor and the first, second, third, fourth, and fifth pressure sensors → record the pressure change data over time as quickly as possible until the pressure of the pressure sensor and the pressure of the volume reference cylinder are at equilibrium (or use automatic interval data collection to collect data every second, set an appropriate data collection interval for automatic recording), and the differential pressure sensor gradually decreases from the maximum to the equilibrium position level at both ends of the core holder.

[0097] Set the data collection interval. When the pressure at the air inlet and outlet of the core sleeve of the high-pressure experimental chamber is balanced and the pressure difference is 8MPa, close the fifteenth valve at the air inlet of the core sleeve of the high-pressure experimental chamber, open the eighteenth valve between the air outlet of the core sleeve of the high-pressure experimental chamber and the volume correction container, and conduct the desorption experiment until the pressure at each side pressure point inside the core sleeve and the outlet pressure are completely balanced with the pressure of the correction container, and automatically calculate the correction and complete the relevant calculations.

[0098] Example 3: Methane Pressure Conductivity Test

[0099] Methane gas equilibrium conductivity experiment: Close the first helium valve and the third valve of the annular pressure container pipeline → Close the fifteenth valve at the core inlet → Open the reference cylinder to vent and evacuate to -0.1MPa, close the fifteenth valve for the sample experiment internal pressure inlet of the high-pressure experimental chamber, open the seventeenth valve for outlet evacuation, and start evacuating the core and volume calibration container in the core sleeve end cap of the high-pressure experimental chamber for 24 hours. After evacuation, close the eighteenth and seventeenth valves; Open the twenty-fourth valve between the methane gas and the volume reference cylinder to allow methane gas to fill the volume reference cylinder, turn on the booster pump connected to the reference cylinder to maintain a pressure of 8MPa → Close the twenty-first valve connected to the methane cylinder Four valves → Prepare six stopwatches or trigger the HMI virtual synchronization start timer → Instantly open the fourteenth and fifteenth valves on the core holder to allow methane gas to enter the core. At the same time, each timer corresponds to the differential pressure sensor and the first, second, third, fourth, and fifth pressure sensors → Record the pressure change data over time as quickly as possible until the pressure sensor pressure and the reference cylinder pressure reach equilibrium (or use automatic interval data collection to collect data every second, set an appropriate data collection interval for automatic recording). The differential pressure sensor gradually decreases from the maximum to the equilibrium position at both ends of the core holder.

[0100] Set the data collection interval. When the pressure at the air inlet and outlet of the core sleeve of the high-pressure experimental chamber is balanced and the pressure difference is 8MPa, close the fifteenth valve of the air inlet of the core sleeve of the high-pressure experimental chamber, open the eighteenth valve between the air outlet of the core sleeve of the high-pressure experimental chamber and the volume correction container, and conduct the desorption experiment until the pressure at each side pressure point inside the core sleeve and the outlet pressure are completely balanced with the pressure of the correction container. The program automatically calculates the correction and completes the relevant calculations.

[0101] The dedicated calculation software matched with the device is used to calculate the standard volume of helium filled in the coal rock core and the pressure equilibrium conduction rate of the 8MPa pressure gas.

[0102] Calculate the standard volume of methane gas filled in the coal rock core, and calculate the pressure equilibrium conduction rate and related parameters of the gas at 8MPa pressure.

[0103] Close the fifteenth valve → slowly open the sixteenth valve at the downstream outlet → observe and record the relationship between the changes in the pressure sensor and differential pressure sensor and time, record the gas production, and record all complete data.

[0104] For the other two sets of methane pressure conductivity experiments: perform an airtightness check to ensure there are no methane leaks during the experiment → complete the methane pressure conductivity experiment according to the helium experiment → organize the experimental data → conduct a similar experiment using water to compare the conductivity of gas and liquid → complete the other two sets of experiments using the same method; use the compiled dedicated data processing software to calculate and process the data, comprehensively compare and analyze the data characteristics of the three different blocks, and evaluate the coalbed methane production potential.

[0105] The device for measuring the pore pressure conductivity rate of the medium and high rank coal core matrix of the present invention obtains key evaluation indicators such as the pressure propagation rate and coalbed methane desorption rate in the porous medium of the medium and high rank coalbed methane coal seam core through relevant experiments, which are related to the physical parameter characteristics of the coal rock itself. The measured parameters are closely related to the production and mining efficiency evaluation of the coalbed methane reservoir block. The measured parameters of the process device can be used to establish the correspondence between the gas production capacity of different coalbed methane reservoir blocks and the physical properties of the coal reservoir rock, and thereby screen high-efficiency production blocks, providing a theoretical basis for the formulation of economical, reasonable and efficient development plans for medium and high rank coalbed methane.

[0106] The device for measuring the pore pressure conductivity rate of the medium and high rank coal core matrix of the present invention uses a high-pressure experimental chamber to simulate the stress state of the natural core formation conditions of coalbed methane to carry out adsorption, desorption, diffusion and seepage. The dynamic sealing design of the high-pressure experimental chamber and the pre-embedded packaging technology of the fluororubber high-pressure segmented pressure measuring holes ensure that when the stress of the high-pressure experimental chamber system changes, the core responds dynamically in the axial and radial compression and expansion processes. The pre-embedded pressure transmission pipe and its joints will not separate and fall off due to repeated displacement and pulling, resulting in the cross-flow of annular pressure and internal pressure, and then cause the pressure system to collapse. A gas absolute volume real-time measurement and calibration system is designed in the process of this device to cooperate with the experimental process to accurately calculate the gas adsorption, desorption, diffusion and seepage rate, and analyze the gas. The segment-sensitive pressure measurement and timing synchronization system can measure the time between the pressure conduction zero point and the impact point, and evaluate the conduction rate. The outlet gas volume metering device and photoelectric bubble detector realize differential measurement correction of the original gas saturation in the porous medium of the core inside the high-pressure sleeve and the gas saturation at each stage during the test. It can also intuitively detect the experimental gas breakthrough pressure and time, providing constraint parameter conditions for experimental evaluation. The device is designed with a data acquisition and processing system consisting of a solenoid valve, temperature sensor, pressure sensor, differential pressure sensor, photoelectric bubble detector, PLC (or microcomputer), and touch screen system. It realizes the dynamic collection, calculation processing and real-time display of experimental data and dynamic tracking changes of experimental process curves.

[0107] The present invention provides a device for measuring the matrix pore pressure conductivity of medium- and high-rank coal cores. When the core gap within a fluororubber sleeve deforms due to axial compression or the axial length of the sample assembly changes within a specified range, it continuously ensures close contact and stress transmission between the sleeve plug and the core. It also minimizes the risk of seal failure caused by sliding between the high-pressure test chamber and the pressure pipeline, thereby improving the reliability of the dynamic seal. The present invention utilizes a precisely calibrated gas volume reference cylinder, a gas desorption tank, an outlet gas volume metering device, and a gas photoelectric bubble detector. Furthermore, it is equipped with a thermometer, a pressure sensor, an electrical control cabinet, a real-time data acquisition system, and a calculation module. This system can display changes in the standard volume of gas in real time and is used to calculate the residual gas content in the porous medium of the coal core within the fluororubber sleeve, thereby forming a differential calculation correction relationship with the process outlet gas volume metering device. The present invention includes a data acquisition and processing system consisting of a solenoid valve, a temperature sensor, a pressure sensor, a differential pressure sensor, a photoelectric bubble detector, a PLC (or microcomputer), and a touch screen system, enabling dynamic acquisition, calculation, processing, and real-time display of experimental data, as well as dynamic tracking of experimental process curves.

[0108] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A device for measuring the matrix pore pressure conductivity of medium and high rank coal cores, characterized by: It includes a helium cylinder, a methane cylinder, an annular pressure container and a high-pressure experimental chamber, wherein the helium cylinder and the methane cylinder are connected to one end of a volume reference cylinder, a desorption tank or a piston container, and the other ends of the volume reference cylinder, the desorption tank and the piston container are connected to a booster pump, one end of the annular pressure container is respectively connected to the helium cylinder, the methane cylinder and the high-pressure experimental chamber input end, and the other end of the annular pressure container is connected to the high-pressure experimental chamber output end, the helium cylinder and the methane cylinder are both connected to the high-pressure experimental chamber input port, the high-pressure experimental chamber output port is connected to the volume correction container input port, and the volume correction container output port is respectively connected to the volume reference cylinder, the desorption tank and the piston container; the high-pressure experimental chamber includes sealed end covers at both ends and a high-pressure experimental chamber arranged between the sealed end covers, a sleeve is arranged in the high-pressure experimental chamber, a core is arranged in the sleeve, a plurality of collection holes are arranged on the sleeve, each of the collection holes is provided with a pipeline, each of the pipelines is connected to a pressure sensor, the input and output ends of the high-pressure experimental chamber are also connected to a pressure differential sensor through a pipeline, and the pressure sensor and the pressure differential sensor are both connected to an electric control cabinet; The volume reference cylinder, the analytical tank, and the volume calibration container are all provided with temperature sensors, which are connected to the electric control cabinet; Both ends of the sleeve are sealed by plugs and sealing rings; the output end of the high-pressure experimental chamber is also connected to a photoelectric bubble detector, which is connected to an electrical control cabinet; pressure sensors are provided on the volume reference cylinder, analytical tank, piston container, volume calibration container and booster pump, and the pressure sensors are connected to the electrical control cabinet.

2. The device for measuring matrix pore pressure conductivity of medium- and high-rank coal cores according to claim 1, characterized in that: Five collecting holes are arranged at intervals on the sleeve.

3. The device for measuring matrix pore pressure conductivity of medium- and high-rank coal cores according to claim 1, characterized in that: An exhaust port is provided at the top of the high-pressure test chamber, and a drain port is provided at the bottom of the high-pressure test chamber; an internal pressure inlet and an internal pressure outlet are respectively provided on the sealing end covers at both ends of the high-pressure test chamber, and an internal pressure inlet hole and an internal pressure outlet hole are respectively provided at both ends of the sleeve.

4. The device for measuring matrix pore pressure conductivity of medium- and high-rank coal cores according to claim 1, characterized in that: A first valve and a second valve are arranged between the helium cylinder and the methane cylinder, a third valve and a fourth valve are arranged on the pipeline connecting the annular pressure container and the high-pressure test chamber, a fifth valve, a sixth valve, a seventh valve, an eighth valve and a ninth valve are arranged on the pipeline between the collection hole and the pressure sensor, and a tenth valve, an eleventh valve and a twelfth valve are arranged on the pipeline connecting the input end and the output end of the high-pressure test chamber.

5. The device for measuring matrix pore pressure conductivity of medium- and high-rank coal cores according to claim 1, characterized in that: A thirteenth valve, a fourteenth valve, and a fifteenth valve are provided on the pipelines connecting the helium cylinder and the methane cylinder to the input port of the high-pressure experimental chamber; a sixteenth valve is provided on the pipeline connecting the high-pressure experimental chamber and the photoelectric bubble detector; and a seventeenth valve and an eighteenth valve are provided on the pipeline connecting the high-pressure experimental chamber and the volume calibration container.

6. The device for measuring matrix pore pressure conductivity of medium- and high-rank coal cores according to claim 1, characterized in that: A nineteenth valve is provided on the pipeline connecting the output port of the volume correction container to the volume reference cylinder, the analytical tank and the piston container; a twentieth valve, a twenty-first valve, a twenty-second valve and a twenty-third valve are provided on the pipeline connecting the volume reference cylinder, the analytical tank and the piston container to the booster pump; a twenty-fourth valve, a twenty-fifth valve and a twenty-sixth valve are also provided on the pipeline connecting the helium cylinder and the methane cylinder to the volume reference cylinder, the analytical tank or the piston container.

7. The device for measuring matrix pore pressure conductivity of medium- and high-rank coal cores according to claim 1, characterized in that: The pipeline of the collection hole is provided with pressure sensors, including a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, and a fifth pressure sensor. A sixth pressure sensor, a seventh pressure sensor, and an eighth pressure sensor are provided on the pipeline connecting the helium cylinder and the methane cylinder to the volume reference cylinder, the analytical tank or the piston container. A ninth pressure sensor is provided on the pipeline of the booster pump outlet.

8. The device for measuring matrix pore pressure conductivity of medium- and high-rank coal cores according to claim 3, characterized in that: The inlet and outlet of the high-pressure test chamber are respectively provided with a tenth pressure sensor and an eleventh pressure sensor, and the exhaust port of the high-pressure test chamber is provided with a twelfth pressure sensor.

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