SU1375995A1 - Method and apparatus for determining rock hardness - Google Patents

Abstract

The invention relates to a technique for measuring the mechanical properties of materials. The purpose of the invention is to improve the accuracy of determining the hardness and informativeness. For this, the surface of the rock sample and 5% 5 rock is affected with a cutter of a material with a greater hardness than the surface hardness of the sample. The sample is rotated at a constant speed around an axis perpendicular to its smooth surface. The amplitude and frequency parameters of oscillations of the cutter interacting with the sample along the circumference line are measured with a given radius in the mode of repeated surface microfracture. The parameters obtained judge the hardness of the rocks. A device for carrying out this method comprises a base 1 on which a massive disk 3 with rotational drive 5 is mounted. On disk 3 there is a device 7 for securing a rock sample fixed on the base of the telescopic rack 14 with a scale of 33 angular values. With the rack 14 by means of a hinge 13 is connected holder 12 of the cutter 10.. To eliminate beatings during sample rotations, the device has a leveling mechanism. For anchoring the position of the section 28 2J 12 .16 "o (L oo ate with

Description

on the basis of 1, a photoresistor 24 and an illuminator 25 are installed, times 1375995

placed in a darkened chamber 26 and separated from the photoresistor by an annular protrusion of a disk 3 with a radial window 27. 27 s. and 2 z. p. f-ly, 4 ill.

one

The invention relates to a technique for measuring the mechanical properties of materials, namely, to determine the hardness of rocks, hardness parameters are used to select the optimal modes of drilling wells in designing methods of their penetration, as well as to determine the hardness of materials used in engineering and instrument making.

The purpose of the invention is to improve the accuracy of determining the hardness and informativity, as well as the exclusion of beats during the rotation of the sample.

FIG. 1 shows a device for carrying out the method, a side view with a partial cut; in fig. 2 - the same, top view; in fig. 3 is a graph of averaged amplitude characteristics of vibration signals recorded from rock samples of different hardness; Fig. 4 shows the amplitude characteristic of the vibrosignals combined with the scanning of the trace of the interaction of the cutter in one turn of the sample.

The device consists of a base 1, on which support 2 has a massive annular disk 3 rotated through friction gear 4 by an electric motor 5. A disk 7 is connected with a ball joint 6 by means of a fixture 7 for securing test specimens 8 of rock.

The cutter 10 of a material with greater hardness, the hardness of the sample surface, rigidly connected with the piezoelectric element 11, which converts mechanical vibrations into electrical signals (vibrations), and the piezoelectric element 11 are fixed to the holder 12, which is hinged 13 is connected to the telescopic stand 14. The position of the holder in the vertical plane is adjustable

and is fixed with a screw 15. The required force on the cutter 10 is achieved by moving the holder 12 of the counterweight 16.

To eliminate the beating of the surface 9 of the sample 8 as it rotates, the device is equipped with a leveling mechanism, which consists of three screws 17 and nuts 18 placed respectively in the holes 19 and the recesses 20 of the housing 7, as well as level 21, rigidly connected to the holder 12. Screws 17 have longitudinal grooves 22 fixed by pins 23. Sample rotation is synchronized with a data carrier (not shown) using a photoresistor 24 and an illuminator 25 placed in a darkened chamber 26, separated by an annular protrusion disk a 3 with a radial window 27.

-The position of the cutter 10 on. the holder 12 is fixed by a screw 28. The test sample 8 is fixed in the fixture 7 by clamps 29, the radial movement of which is carried out by screws 30. I

Angle of rotation p holder 12

(Fig. 2) relative to the center of rotation 31 of the sample 8 is controlled by an arrow 32 on a degree scale of 33 angular displacements. The angle jB is determined by the required speed of interaction of the sample 8 with the cutter 10..

For the purpose of binding the positions of differently hard areas of the sample surface with the information carrier, the device is equipped with a photoresistor and illuminator, separated by an annular protrusion of a disk with a radial window, the illuminator being placed in an annular darkened chamber, and the photoresistor is electrically connected with the transducer of the recorder tags.

The method is carried out as follows.

After securing sample 8 in tool 7, surface 9 is aligned with the plane of the horizon. For this purpose, by turning the nuts 18, the holder 12 is horizontally positioned at points 34-36 at an angle of 120 ° on the circumference of a selected radius 37. Then the device is connected to the power grid by means of the terminals 38 of the electric motor 5 and the sample is rotated with constant scattering around an axis perpendicular to its smooth surface, the amplitude and (or) frequency parameters of oscillations of the tool interacting with sample 8 along a circumference line with a given radius in the repetition mode are measured. superficially microfracture. In the process of interaction with the sample 8 during its rotation, the cutter 10 performs predominantly normal vibrations, which, after being converted by the piezoelectric element 11 into electrical signals, are fed through terminals 40 to a preamplifier 41 and then through a spectrum analyzer (or band pass filter) 42 to the input of a recording device 43. The preamplifier 41 vibration signals are also fed to the frequency meter 44. The photoresistors 24 are connected via terminals 45 to the marker converter of the recording device 43.

.Example. The hardness of samples of rocks and metal disks on the device with dimensions of 0.41 x X0, 33x0.36 m and a mass of 15 kg is determined.

The tests are carried out with the following parameters and modes:

The diameter of the subjects

samples, m O, 022 ... 0.1 Range of hardness determination. Pa (70-550) x10

Static

line per cutter, kgf O, 06 ... O, 250 Sample rotation speed, rpm (rad / s) 3.5 ... 40

(O, 36 ... 4.18) Sample movement speed relative to the cutter, m / sO, 004 ... O, 18

Q 5 0 5 Q

0

Radius of interaction of a cutter with a sample, sample, m 0.015 ... 0.045 Measuring time constant 0.3 ... 3.0 Get (Fig. 3) averaged amplitude parameters of vibration signals for limestone 46, granite 47 and ferruginous quartzite 48. Similar characteristics are obtained for metals of different hardness.

The analysis of graphite shows that already with an interaction time of no more than 20 ... 40 s, stabilization of measured values of vibration signals occurs, which significantly differ in the level of rocks of different hardness.

To determine the hardness in terms of the force applied to a given die area, a graph or correlation equation is used between the amplitude and (or) oscillation frequency of the cutter 10 with the hardness of the material under study.

When quantifying the distribution of hard and soft inclusions in the rock per unit path of interaction between the cutter and the sample, its rotational speed and measurement time constant are reduced, as well as the sensitivity of vibration amplitude detection is increased. For this, the position of the radial window 27 (Fig. 2) is aligned with the characteristic point a, due to the hardness of the rock in terms of hardness, using screw 30 to loosen the clamp of sample 8 and rotate it until point a is on the same straight line connecting the center of rotation 31 with a radial window 27.

The amplitude characteristic 49 of the vibration signals (FIG. 4) is combined with a different; twisting the circumference of the track of the interaction of the cutter 10 with a radius of 37 for one revolution of the sample 8.

I

An analysis of the amplitude distribution of vibration signals shows that quartz with a hardness of 200x10 Pa (204 kg / mmO is 0.3 times the circumference of the interaction trace and 0.7 shale with a hardness of 38x10 Pa (39 kgf / mm). The measured amplitude of the vibrosignal at different interaction radii, parameters are obtained “The distribution of hard and soft inclusions over the entire surface of the rock sample under investigation.

The use of the method and device for its implementation, in addition to increasing the accuracy and resolution of determining the hardness of rocks, allows increasing by 5 ... to times the amount of information obtained by a single measurement (per sample turn) relative to the static punching method; reduce the time and expense of cutting tools for the preparation of samples for testing by about two times (due to the possibility of determining the hardness on samples with one smooth surface); Determine the hardness of layered rocks on small diameter core samples of 0.022. . .0.05 m without their destruction, assess the degree of heterogeneity of rocks, i.e. the relative amount of hard and soft inclusions, as well as the determination of hardness in a dynamic mode, which, in contrast to the static method of indentation of a punch, largely reflects the actual process of drilling a well.

Claims (4)

1. A method for determining the hardness of rocks, including an impact on the surface of a sample of rock by a cutter made of a material with greater hardness than the hardness of the sample surface, and measuring the parameters of oscillations of the cutter, which determine the hardness of the rocks, which is , with the aim of. To increase the accuracy of determining the hardness and informativity, the sample is rotated at a constant speed around the axis, perpendicular to its plane of the smooth surface, the amplitude .0 5 0 Q five The tedious and / or frequency parameters of oscillations of the cutter interacting with the sample along a circle with a given radius are in the mode of repeated surface microfracture. 2. A device for determining the hardness of rocks, including a cutter, a piezoelectric transducer, a registering device and an indicator, characterized in that it is provided with a base mounted on it by a massive disk with a rotating electric drive, a fixture mounted on the disk for mounting a rock sample fixed on a telescopic base a stand with a scale of angular values, a cutter holder, the cutter being rigidly connected to the piezoelectric transducer; the holder is connected to the telescopic stand by means of a hinge and mouth It can be rotated in a plane parallel to the axis of rotation of the massive disk and not passing through it, as well as with the possibility of changing and fixing its position in the vertical and horizontal planes. 3. The device according to claim 2, which is such that, in order to exclude beats when the sample is rotated, it is equipped with a leveling mechanism for the sample surface. 4. The device according to claim 2, which is equipped with a photoresistor and an illuminator with a darkened camera, a tag sensor, mounted on the base, a massive disk made of an annular and radial window in an annular protrusion, the illuminator and the photoresistor being placed along different sides of the annular protrusion of the disk, and the photoresistor is connected to the transducer tags of the recording device. 2  -i s ts five time j with fig.d FIG.