CN1009389B - Rock core high pressure seepage and pore measuring instrument and using method - Google Patents

Abstract

The invention discloses a measuring instrument for measuring the physical properties of a rock sample, which comprises a rock core holder, a power pump, a high-pressure gas cylinder, a control valve, a pressure gauge, a connecting pipeline and the like, can measure the physical quantities such as permeability, porosity and the like of the rock sample in three axial directions under the vertical pressure of 113MPa and the lateral pressure of 50MPa, can simulate the stress condition of a rock stratum under the depth of 4,000M at the deepest, and has the advantages of accurate and reliable measurement data, good repeatability, wide application range, capability of measuring the rock sample with any properties and the like. Therefore, the defects of poor formation simulation, narrow adaptability and measurement range, inconvenient porosity measurement and the like in the conventional instrument are overcome.

Description

The invention belongs to an instrument and a measuring method for measuring physical properties such as full diameter, triaxial permeability and porosity of obtained rock cores under conventional and simulated stratum pressure conditions in geological exploration. It is especially suitable for measuring and analyzing the physical properties of rock formations in oil and gas field exploration.

The size of formation confining pressure (including vertical and lateral pressure) has a great influence on the porosity and permeability of rock. Therefore, accurately measuring the physical properties such as permeability and porosity of rock samples under simulated formation pressure conditions has important practical and theoretical value for the study and evaluation of oil and gas enrichment, reserves and production (quantity) , but currently widely used at home and abroad is to use small rock samples to measure physical properties under normal pressure or low pressure. The confining pressure usually does not exceed 1.4MPa (MPa), and the applied confining pressure often has only one side pressure. For example, the turret-type permeability tester (model 3020-144) produced by the American Core Experimental Company has only one side pressure. pressure, but no axial pressure, its maximum lateral sealing pressure is 1.4MPa (MPa), the maximum upflow pressure of seepage medium (gas) is 0.3MPa (MPa), and the lower limit of permeability measurement is 9.87×10 ^{- 6} um ² (square micrometer), if it is less than this value, it cannot be measured, which greatly limits the scope of application. In addition, this instrument can only use gas as the sealing medium, and it must be used on-line with the extended helium porosimeter when measuring porosity, so it is inconvenient to use. In addition, U.S. Patent 4,599,891 discloses a three-dimensional rock core holder. Though it has two confining pressures, it is also more convenient to fold and assemble, but it cannot measure radial permeability and porosity. not tall. And although its confining pressure can reach 1000PSig in the "multi-rock sample porosity and permeability automatic measuring instrument and method" and "rock sample automatic measuring instrument and method" disclosed by two patent documents of U.S. Patent 4,573,342 and 4,649,737, it acts on the rock core. The axial pressure on the sample can be as high as more than 130 pressure, and the porosity can also be measured, and the degree of automation in the measurement is also high, but the lateral pressure is low. When the lateral stress is high, the instrument cannot perform analog measurement , and can only measure the axial permeability of the rock sample but not the radial permeability. This is a good simulation and practical for the determination of the full diameter, large rock core samples and the rock samples of heterogeneous rock formations. Sex is poor.

The purpose of the present invention is to develop a method that can simulate the lateral pressure and vertical pressure of different formation depths. Under the condition of pressure, the physical properties of the permeability of the core are measured in the three axial directions of X, Y, and Z. And measure the porosity of the same core to match the data. The actual lateral pressure of the rock core can reach up to 50MPa (MPa), and the vertical pressure can reach up to 113MPa (MPa), which can simulate the stress state of the deepest rock formation equivalent to 4000m. And it has accurate and reliable measurement data, good repeatability, wide application range, and can measure any rock sample, especially heterogeneous low permeability and low porosity rock samples, so as to overcome the conventional instruments when measuring rock samples. The purpose of disadvantages such as poor simulation of the formation, poor adaptability, narrow measurement range, and narrow application range.

The solution of the present invention is to have two pressure-sealed rock core holders, two manual screw pumps as high-pressure power sources, two hydraulic cylinders as intermediate containers, and two cylinders containing nitrogen, helium and other gases. The pipeline and measurement system composed of high-pressure gas cylinders, various pressure gauges, connecting pipes, control valves, quick connectors, and gas flowmeters of various specifications can achieve the above-mentioned purposes. Accompanying drawing 1 is its working principle diagram, wherein: the function of the core holder III is to apply different vertical pressure and lateral pressure to the rock sample according to the requirements, so that it is under different pressure states for the measurement of various physical properties; The role of manual screw pump Ⅰ and Ⅱ is to provide working pressure to the two sealed pressure chambers of the holder and 1 ^# and 2 ^# hydraulic cylinders (the pressure fluid is light oil or water), so as to meet the requirements of core determination. Pressure conditions; pressure gauges are used to control the pressure values of various media when working; each control valve is used to control the on-off and flow direction of different working media; quick connector groups 27, 28, 24 and 30, 31 are used to quickly switch Through the measurement of the rock core and the vertical pressure and lateral pressure medium; there is a sessile piston 57 in the 1 ^# and 2 ^# hydraulic cylinders, which divides the pressure chamber into two parts, and its function can provide various seepage media to be measured for the rock sample , can also provide other liquid pressure transmission media as working power for the side seal pressure chamber 37 and vertical pressure chamber 47 of the core holder; high-pressure gas cylinders V and VI provide gas measurement media for the rock sample to be tested.

One of the key technologies for realizing the present invention is the structure and sealing of the core holder III. Accompanying drawing two is the sectional view of rock core holder, and wherein 33 is holder body, and 34 is bottom plug, and 50 is top plug, and both all are connected with body 33 by screw thread, and vertical pressure sealing chamber 47 is positioned at pressure piston 45 and Between the top plugs 50, the function of the spring 52 is to ensure that the vertical sealing chamber 47 has a minimum space and make it face the pressure liquid inlet hole 30; Linear flow; 54 is a diffusion plate, 55 is a diffusion tile, both of which are metal plates with mesh grooves, and the mesh grooves make the measuring medium evenly distributed in the rock sample under pressure. Replace the diffuser plate 54 with a dull plate (i.e. a block without grooves and holes); The side pressure required in the measurement comes from the fluid pressure in the side seal pressure chamber 37 acting on the rubber cylinder, which is realized through the elastic deformation of the rubber cylinder; the vertical pressure is directly applied to the vertical seal pressure through the diffusion plate 54 through the pressure piston 45 The section of the rock sample 44; the high-pressure quick connectors 30 and 31 are respectively the inlets for the vertical sealing pressure and the side sealing pressure fluid. 32 is the air discharge port of the side sealing pressure chamber; 40 is the side pressure cap, 41 is the side core pipe, 43 is the vulcanized iron core, the outer surface of the vulcanized iron core is closely connected with the rubber tube 38 through a rectangular groove, and the inner cylindrical surface is It moves with the side core tube 41 and is sealed by two O-shaped rubber rings. The contact surface between the side core tube and the two ends of the vulcanized iron core is O-shaped rubber ring 39, which is sealed by the pressure of the side pressure cap 40 to prevent side The pressure medium in the pressure chamber pollutes the rock sample; 35, 36, 42, 46, 48, 49, and 51 are all O-shaped rubber sealing rings, which respectively seal the space between the two pressure chambers and the outside of the pressure chamber to prevent Ensure that the pressure medium will not penetrate or leak under high pressure; the screw pumps I and II pass the control valves 19, 20 and 18, 14, 17, and 10 respectively to the vertical sealing pressure chamber, side sealing pressure chamber and 1 ^# , 2 ^# hydraulic pressure The cylinder provides pressure liquid, and the maximum working pressure of the two screw pumps can reach 60MPa (MPa). Supply of measurement medium: firstly, high-pressure gas cylinders Ⅴ and Ⅵ provide gas measurement medium to the rock sample to be tested through control valve 1, high-pressure pressure regulating valve J, control valves 5, 6 and quick connector groups 28, 24, 27 respectively , such as nitrogen, helium and other high-pressure gases; secondly, the gas flowing through the high-pressure pressure regulating valve J can also provide high-pressure gas to the 1 ^# and 2 ^# hydraulic cylinders through the control valves 3, 13 and 4, 9 respectively as the power fluid of the hydraulic cylinders . Attached drawing 3 is a sectional view of the hydraulic cylinder. The structure and size of the 1 ^# and 2 ^# hydraulic cylinders are the same. The structure of the cylinder body is symmetrical. The polytetrafluoroethylene sealing ring 58 is assembled to prevent the pressure medium in the upper and lower chambers from infiltrating each other. The upper part holds light oil and is connected with the screw pump and high-pressure gas cylinder, and the lower part holds liquid measuring medium. The measuring medium contained in 1 ^# and 2 ^# hydraulic cylinders can pass through the control valve 15 or 11 and the quick joint group 28 or 27 respectively Provide liquid measuring medium to the rock samples respectively. In addition: 1 ^# and 2 ^# hydraulic cylinders can provide other pressure liquids as sealing medium to the vertical sealing pressure cavity and the side sealing pressure cavity through the control valves 16 and 12 respectively. In accompanying drawing 1, A, B, C are gas pressure gauges, and 7,8 are the control valves of pressure gauges B, C, and K is a low-pressure regulator valve. The control range of A meter is 0~15MPa (MPa), the control range of B and C meters is 0~1MPa and 0~0.1MPa (MPa); E and F are hydraulic meters, and the control range is 0~60MPa (MPa). ), D is the precision pressure gauge used when measuring the porosity of rock samples, and the measuring range is 0-0.6MPa (MPa); the six-way valve 29 is used to select the gas measurement medium; G is the gas flowmeter of various specifications (when Use a measuring cup when measuring with liquids). The lateral pressure that may be applied to the rock sample to be tested during the measurement can reach up to 50MPa (MPa); the vertical pressure, because the area of the diffusion plate 54 is equal to the lower end of the pressure piston 45 and much smaller than the upper surface in the vertical pressure chamber Therefore, the actual pressure acting on the rock sample can reach up to 113MPa (MPa). The diameter of the part in contact with the core in the middle of the rubber tube is φ100mm or 65mm, which is suitable for the determination of cores obtained by 8 1/2 "and 6 1/2" core drill bits, or after processing cores of other specifications To measure.

The invention has two sealing pressures, vertical and lateral, and the core holder has good sealing performance and high strength, and can make the rock sample to be tested under a lateral pressure of up to 50MPa (MPa) and a vertical pressure of 113MPa (MPa). Carry out the determination of various physical properties, and can ensure safety and prevent leakage. The invention can not only measure the permeability, but also measure the porosity, and at the same time, it can also analyze the acidification effect of the rock sample and measure the elastic coefficient of the rock. Since the present invention is equipped with two hydraulic cylinders, both gas and various liquids can be used to measure the permeability. Compared with similar products produced by American Rock Core Testing Company, etc., the present invention can measure the permeability of any rock sample because the lower limit of permeability measurement can reach 9.87×10 ^-12 um ² (square micrometer), especially suitable for low permeability Sexual rock samples. At the same time, when measuring rock samples with different permeability, two pressure regulating valves J and K and three pressure gauges with different ranges A, B and C are used respectively, thus ensuring the accuracy of the measurement. Therefore, compared with other similar products, the present invention has the advantages of high working pressure, strong stratum simulation, wide measurement range, accurate and reliable measurement data, good repeatability and the like.

Example:

Take the measurement of a rock core with a diameter of φ100mm and a length of 110-180mm as an example: the inner diameter of the rubber cylinder is φ100mm, the length is 300mm, the thickness of both ends is 10mm, and the material is oil-resistant rubber; the pressure head of the pressure piston 45 and the diffusion plate 54 The diameters are all φ100mm, and the force bearing area of the pressure piston in the pressure chamber is 178.16Cm ² ; the inner diameter of the holder body is 160mm, the wall thickness on both sides is 35mm, the height is 660mm, and the material is 35 chrome molybdenum steel. The smoothness is grade 10; the bottom plug 34, the top plug 50, the side pressure cap 40, and the pressure piston 45 are also No. 35 chromium-molybdenum steel. The vulcanized iron core 39 has an inner hole diameter of φ18mm, an outer diameter of φ50mm, and a height of 23.5mm. There are two annular rectangular grooves on the outer cylindrical surface of the iron core and are hot-pressed with the rubber tube; The sealing rings are made of oil-resistant rubber. The hydraulic cylinder head 59 and cylinder body 60 are made of No. 35 chrome-molybdenum steel. The outer diameter of the steel is φ170mm and the inner diameter is φ120mm. The cylinder head and the cylinder body are connected by threads and sealed with rubber rings. For sliding fit, and through two sets of polytetrafluoroethylene sealing rings 58, to prevent the upper and lower parts of the pressure medium in the cylinder from infiltrating each other. In this embodiment, the screw pumps I and II both use the screw pumps in the 600-type pressure gauge calibration instrument. During the measurement process, 1 ^# , 2 ^# hydraulic cylinders and holders are connected with the entire measurement system through high-pressure quick connectors.

The measuring method of the present invention is as follows: firstly put the rock samples to be tested divided into four quadrants into the holder III, install the filling plug 53 in the pressure piston 45 and the bottom plug 34, and tighten the top plug and the bottom plug. Then connect the high-pressure quick connectors 30 and 31. When measuring the gas permeability of the rock sample, open the control valves 19 and 20, and inject the pressure liquid into the vertical sealing pressure chamber 47 and the side sealing pressure chamber through the screw pumps I and II respectively. 37, and control the pressure respectively through the pressure gauges E and F, so that the rock core to be tested is under the required pressure. When the pressure reaches the required value, open the six-way valve 29 to connect with a certain designated gas cylinder and control the pressure value of the gas through the control valve 1, the high-pressure pressure regulating valve J, and the pressure gauges A, B, and C. When measuring the permeability of the 1st and 3rd quadrants in the horizontal direction, the high-pressure quick connectors 24 and 27 are connected, (the standard frame IV is not used at this time) and the control valves 6 and 23 are opened for measurement. When measuring the permeability of the 2nd and 4th quadrants in the horizontal direction, after the vertical sealing pressure chamber 47 and the side sealing pressure chamber 37 are depressurized, the bottom plug 34 of the core holder is removed, and the rock sample in the rubber tube 38 is rotated 90° ° After that, install the bottom plug and repeat the above operation to measure the horizontal permeability of the 2nd and 4th quadrants. When measuring the permeability in the vertical direction of the rock sample, connect the control valve 5 to the high-pressure quick connector 28, close the control valves 23, 26, and open the control valves 5, 21, 22 to measure the vertical permeability of the rock sample.

When it is necessary to measure the liquid permeability of the rock sample, first install the liquid medium to be measured on the lower part of the 1 ^# and 2 ^# hydraulic cylinder pistons 57, and then connect the high-pressure quick connector groups 27, 28 to the control valves 11, 15, Then, when the pressure is adjusted to the required value through the high-pressure pressure regulating valve J, the control valves 4, 9 and 3, 13 are opened to input the gas as the power source to the upper part of the two hydraulic cylinders. When the vertical pressure and lateral pressure of the rock core reach the required value , open the control valves 11, 23 to measure the liquid permeability in the horizontal direction of the rock sample, and open the control valves 15, 21, 22 to measure the liquid permeability in the vertical direction of the rock sample. Among them, G is a gas flow meter or a measuring cup of various specifications, and the control valve 2 is an exhaust valve.

When carrying out rock core porosity measurement, then change the two diffusion plates 54 in the rock core holder into dull plates, connect the valves 25, 26 on the standard body frame IV with the high-pressure quick connector groups 24, 27 respectively, Make it connected in series in the pipeline between the high-pressure gas cylinder and the core holder, open the control valves 6 and 25 to control the pressure value through the precision pressure gauge D, H is the standard body, when the gas pressure reaches the required value , close the control valve 25, open the control valve 26, and send air to the rock sample to measure the porosity of the rock sample. When measuring the porosity, the rock core is still in the required vertical and lateral pressure, and the control valves 21, 22, 23 are closed during the measurement.

Attached picture:

Fig. 1 is the flowchart of the present invention;

Figure 2 is a sectional view of the core holder;

Figure 3 is a sectional view of 1 ^# and 2 ^# hydraulic cylinders.

Claims (7)

1, a kind of core high pressure oozes, the hole analyzer, it is by rock core fastener, power pump, gas cylinder, operation valve, tensimeter, formations such as fluid meter connecting tube, it is characterized in that it also comprises two hydraulic cylinders as intermediate receptacle, one cover standard body frame, this standard body frame can be serially connected with in the pipeline between gas cylinder and the clamper by high-voltage quick joint and use, and an end of two hydraulic cylinders all can join with gas cylinder or hand screw pump respectively through valve and pipeline by high-voltage quick joint, obtaining gases at high pressure or the liquid medium as power, the other end then can join with clamper respectively by high-voltage quick joint etc.; So-called power pump then is to adopt two pressure can be provided is the hand screw pump of 60MPa (MPa); And in the body of rock core fastener, have vertical and two envelope pressures of side direction chamber, wherein vertical envelope presses the chamber between pressure piston and top plug, two envelopes are pressed between the chamber and envelope is pressed between chamber and the outside and all adopted O type rubber sealing, and this clamper is by the use that links together of high-voltage quick joint group and whole measuring system.

2,, it is characterized in that it is made of clamper body 33, packing element 38, bottom plug 34, top plug 50, pressure piston 45, side pressure cap 40, side core pipe 41, spring 52, bushing plug 53 etc. by the described analyzer of claim 1.

3, by the described analyzer of claim 1, so-called hydraulic cylinder, it is characterized in that it is made of cylinder cap 59, cylinder body 60, stockless piston 57 etc., piston 57 can be free to slide in cylinder body and inner chamber is divided into upper and lower two parts, two groups of teflon seal rings 58 are arranged on the piston, cylinder cap 59 passes through spiral marking connection with cylinder body 60, and utilizes the sealing of O type rubber ring.

4, by the described analyzer of claim 1, so-called standard body frame is characterized in that it by operation valve 25,26, precision pressure gauge D, and standard body cover H and rapid-acting coupling constitute.

5, by the described rock core fastener of claim 2, so-called rubber tube, it is characterized in that on the rubber tube on the outer of sulfuration iron core 43 twice ring-type rectangular channel being arranged, the sulfuration iron core is by this groove and rubber tube heat pressure sealing, the packing element middle part is φ 100mm or φ 65mm with the internal diameter of core contact site, length is 300mm, and two-end thickness is 10mm, and material is an oil resistant rubber.

6, using method by the described analyzer of claim 1, it is characterized in that can be under high pressure, at X, Y, three of Z axially go up core are carried out gas permeability, the mensuration of physical quantity such as Test Liquid Permeability of Core and factor of porosity, the rock sample to be measured that at first will be divided into four quadrants before the measurement is packed in the rock core fastener III, at pressure piston 45, all load onto bushing plug 53 in the bottom plug 34, on press closer plug, bottom plug, connect high-voltage quick joint 30 then, 31, elder generation is with operation valve 19 during measurement, 20 open, by the screw pump I, II is divided the vertical envelope pressure of pressure liquid injection chamber 47, press in the chamber 37 with side seal, core to be measured is under the required pressure;

When measuring the gas permeability of core, opening six-way valve 29 connects with the gas cylinder of appointment, and by operation valve 1, septum valve J, the force value of tensimeter A, B, C pilot-gas, when measuring 1,3 quadrant permeabilities of horizontal direction, high-voltage quick joint group 24 and 27 is connected, and opening controlling valve 6,23 just can be measured, and after the mensuration two envelopes is pressed after the release of chamber, with the core half-twist in the packing element 38, just can carry out the mensuration of 2,4 quadrant horizontal permeabilities more as stated above; When measuring the vertical direction gas permeability, then rapid-acting coupling 28 and operation valve 5 are connected, while closed control valve 23,26, opening controlling valve 5,21,22 just can be measured;

When need are measured the Test Liquid Permeability of Core of core, also liquid medium to be determined need be loaded on the bottom of 1,2 hydraulic cylinder pistons 57 respectively, again high-voltage quick joint group 27,28 is connected with operation valve 11,15 respectively, when by septum valve J its pressure being transferred to required value then, open operation valve 4,9 and 3,13 gas is imported the top of two hydraulic cylinders as power source, when the pressure at right angle of core and lateral pressure reached required value, opening controlling valve 11,23 can carry out the mensuration of the Test Liquid Permeability of Core of core horizontal direction; Opening controlling valve 15,21,22 then can carry out the mensuration of the Test Liquid Permeability of Core of vertical direction to core;

When carrying out the core porosity determination, then should change two diffuser plates 54 in the rock core fastener into vexed plate, with the valve 25 on the standard body frame IV, 26 respectively with high-voltage quick joint group 24,27 connect, it is serially connected with in the pipeline between gas cylinder and the rock core fastener, when core is in the vertical and lateral pressure of requirement, opening controlling valve 6,25, control its force value by precision pressure gauge D, when gas reaches required value, closed control valve 25, opening controlling valve 26, supply gas to measure the factor of porosity of core to rock sample, operation valve 21 during measurement, 22,23 all are closed condition.

7, by the described using method of claim 6, it is characterized in that measurement so-called high pressure under be meant rock sample reach as high as 113MPa vertical depress with the 50MPa side pressure under measure.

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