SU495589A1 - Device for measuring porosity and skeletal volume of rock samples - Google Patents

Description

one

The invention relates to the field of testing rocks and similar porous materials and is intended to determine the open and effective porposts of rock samples (porous materials), as well as the skeleton volume of the samples necessary to calculate its density.

The measurement of porosity is the most widespread of the definitions in the study of the physical properties of rocks, and therefore an increase in labor productivity in these definitions, as well as an increase in their accuracy, is highly relevant.

The gas-lumipometric method for determining open porosity has a number of advantages compared to liquid and massometric, however, due to the lack of safe, simple, high-performance and sufficiently accurate instruments, it is not widely spread.

The major drawback of most known gas meters is the use of toxic mercury and measuring only the volume of the skeleton (solid phase) of the rock. The design of the first gas volume, including instruments that are not used to determine porosity, does not allow for the simultaneous measurement of the skeleton volume and the total sample volume required for the calculation of the flow rate.

In the B. Sazonov ii3BecTHOM instrument, designed to measure the volume and porosity of solids, the sample is applied to the porous membrane but is mercury free. The outer volume of the sample is determined by the mercury filling of the cup covering the sample, therefore, mercury is in direct contact with the sample. Pore volume is determined through a gas-permeable membrane based on Boyle Mariotte's law.

Another well-known mercury device, produced in small batches, consists of a hermetically sealed chamber, to the fitting of which a glass burette is attached, supporting the expansion of a spherical shape of about 10 cm. The lower part of the burette is connected by a hose to a vessel with mercury, which in turn is connected to a splash with

water II with a mercury manometer. In the course of the experiment, with the help of a bellows with mercury, the air from the calibration of the burette into the measuring chamber is crushed, and the pressure necessary for this is counted by a mercury gauge.

Claims (1)

When determining the porosity with the indicated device, the volume of the sample of the correct form is determined geometrically by measurement. In the case of samples of the recipe shape, the volume is determined by filling them with sand in the instrument glass, followed by determining the volume of the skeleton of this sand without specimens in the instrument, of course, the accuracy of the determination is low. The use of toxic mercury in gas-lumipometric priors makes them dangerous in operation and eliminates the possibility of using them in field conditions for rapid mass definitions. The need to determine the total volume of the sample outside the device by measuring or hydrostatically weighing the parasinated sample makes the porosity determination process much more difficult and deprives the device of rapidity. The purpose of the invention is to provide simultaneous gas-luminometric1 measuring the volume of the skeleton and the total volume of the image. This is achieved by the fact that the proposed device includes an elastic bag that separates the measuring chamber into two hermetic cavities, each of which is connected to the prechamber and has an exit in the atmosphereThe proposed device is based on the principle of free expansion of gas with an excess pressure of 25 when it is bypassed from one volume to another. The measurement scheme does not require vacuumed. This makes it possible to determine effectively the growth capacity of partially water-saturated samples (for example, when studying the residual water saturation of rocks). The gas-human method of measuring porosity keeps the structure and surface properties of the samples unchanged. The use of standard USEPA element assemblies mounted on a plateau, as well as the use of a standard rubber dingy as an elastic partition, makes the fabrication of the equipment, increases usability and during transportation, and practically excludes the possibility of damage. In view of this, the device can be used as an express field device, as well as a stationary laboratory instrument. Pa figs. 1 is a schematic diagram 45 of the proposed device; in fig. 2 - device, section; in fig. 3 - the same plan. The device consists of a cup 1, on the sealing surface of which is placed an elastic bag 2, which divides the internal 50 volume of the cup and two airtight cavities a and b. With the screw clamp 3, the cup 1 is pressed against the finger 4, while the elastic bag acts as a seal against the gasket of the chamber. Pt 4 is fixedly mounted on the plateau 5, in which 55 the system of connecting channels 6 and 7 is made. The system of channels 6 communicates pneumotummers 8 and 9 and pianoforte 10 and 11 with an exemplary mortar 12, ieno-fixed to GO 5. At. The power of channel 7 is the bottom of the cup 1 and is connected by a capillary hose 13 with a pneumo-tumbler 9. The pneumatic valve 10 is connected by a hose to a gearbox 14 installed on the gas line, and the pneumatic valve 65 is connected to the sylphus 15 with a non-return valve or a Schipz pump (not shown) . In the proposed device, by creating a two-cavity measuring chamber, two of the measuring circuits are carried out. The first consists of a variable volume of cavity a and includes the volume of the hose 13 and a part of the volume of the unweldabled 9. The second is composed of a non-temporary volume of the cavity b, channel 7 and part of the volume of the pneumotumulator 8. The role of the pre-chamber with overpressure removes the volume consisting of the variable volume of the pressure gauge 12, the volume of the system of channels 6 and part of the volume of the inevitel switch 8 and 9 limiting it and the ventilation valves 10 and I. The pressure of the gas in the prechamber rises to the value specified with the help of a compressed gas source and a gear 14 or an individual point (for example Schinz pump or car pump with a receiver (volleyball ball). The proposed device works as follows. When removing the glass 1, the open valve AND, the toggle switch 9 and the toggle switch 8 off, the bellows 15 or the Schinz pump through the system of channels 6 from the cavity a suck up air until the elastic bag is stretched to the full size of the chamber a to b glass 1. 4, the test specimen was placed with a small foot, with dimensions corresponding to the dimensions of the chamber and devoid of sharp corners. Pack the sample with cup 1 and press the cup with a screw clamp 3 until it is fixed and the flywheel is positioned. Close the valve 11 and, without changing the position of the toggle switches 8 and 9, by opening the valve 10, the pressure is brought to the working pressure. The elastic bag) in this case fits the sample tightly, squeezing the air out of the cavity b into the atmosphere through channel 7 and the tumbler 8, communicating it with the atmosphere in the “Off” position. Close the valve 10 and, observing the performance of the pressure gauge 12, assess the tightness of the system. In the case of tightness, the toggle switch 9 is turned to the off position, this releases excess pressure from the cavity to atmospheric through a hose 13 and toggle switch 9, which connects it to the atmosphere in this position, and allows it to measure porosity. and the volume of the skeleton of the samples. Consider, for example, the operation of the device when implementing the following procedure: the preset overpressure in the prechamber, installed on the pressure gauge 12, opening of the toggle switch 9, is vented into the hermetic cavity a and recording the new meter reading corresponding to the pressure set The integrated chamber “prechamber | measuring volume while maintaining a pressure equal to atmospheric in the cavity b in the pores of the sample. The subsequent opening of the toggle switch 8 bypasses the steady-state overpressure from the combined chamber “chamber + volume a and volume b” and records the new reading of the pressure gauge in the joint system “chamber keeper + volume a- volume b. The obtained two pressure values are sufficient to calculate the porosity and volume of the rock skeleton based on the Boyle-Mariotte law with the known parameters of this device and the barometric pressure at the time of measurement. Instrument parameters are determined using standards. Apparatus of the Invention A device for measuring the porosity and the volume of a skeleton of rock samples, preferably of cylindrical shape with a cleaned one side, containing a chamber for placing a sample, a pressure gauge and gas switching elements, characterized in that it provides simultaneous gas-luminometric measurement of the skeleton volume and overall the sample volume, it includes an elastic L1 spacer, which divides the measuring chamber into two hermetic parts and .. n, 1 n of which are joints, each of which is connected to orkameroy and opens into the atmosphere at J.Fc I 2 J3 3 Fig 1 Fig 2 YU 12 ig-3