SU1492053A1 - Method of determining the degree of textural anisotropy of rock - Google Patents

Abstract

The invention relates to mining. The goal is to increase productivity. On a sample of rock in the form of a core (K) with a layered structure, the velocities of the propagation of ultrasonic vibrations (UT) are measured in three mutually perpendicular directions (H). One of H coincides with the diameter K directed along the stratification. The second H coincides with the diameter perpendicular to the first. The third H is oriented along the longitudinal axis of the core. According to values of sound velocity determined by the degree of texture rock ^{_{anisotropy: A = V X / (.}} V Y V Z), where V _X - ultrasonic testing speed along a diameter, is coincident with the direction of lamination K

V _Y - speed of ultrasonic testing along the second diameter

V _Z - the speed of the ultrasonic inspection along the longitudinal axis of the core. The method allows to simplify the preparation of samples for measurements. 3 il.

Description

The invention relates to mining and is intended to study the mechanical properties of rocks.

The purpose of the invention is to increase productivity.

Figure 1 shows a layered rock sample (core) prepared for measurements, a general view; 2 is the same vertical section with the indication of the directions of measurements; FIG. 3 is the same horizontal section.

The method is carried out as follows.

Cores 1 are taken with a layered texture visually visible on its surface (Fig. 1). It does not require special core preparation and layering (schistosity) can be directed at any angle to the core axis. For measurements, any cores that have at least an approximate parallelism of the ends and allow coaxial installation of ultrasonic transducers can be used.

On core samples selected for measurement, emitters 2 and receivers 3 of ultrasonic pulses are placed in three mutually perpendicular directions. In this case, one of the directions (X) coincides with its diameter, directed along the stratification of the core.

four

WITH

yo

about ate

with

the second. The base (Y) coincides with the core diameter, perpendicular to the first one, and the third direction (Z) coincides with the longitudinal axis of the core. In each direction, ultrasonic vibrations are excited, their propagation rates are determined, and the degree of texture anisotropy of the rock is determined by the formula

BUT

 -Yi

v.v,

where v. the speed of propagation of ultrasonic vibrations along the diameter coinciding with the direction of core lamination; the speed of propagation of ultrasonic vibrations along the second diameter; velocity of propagation of ultrasonic vibrations along the longitudinal axis of the core. The proposed method is based on the following physical assumptions.

The degree of anisotropy is determined from the relative velocities along and across the bed of the rock, i.e.

-.

where the unknown quantity is V is the velocity of propagation of ultrasonic vibrations across the layering. Dp of its determination, it is assumed that all factors determining the velocities of elastic waves (density, mineral composition, porosity, etc.) are uniformly distributed in the samples under study. Then the main factor determining the change in velocity remains its direction relative to the layered planes. Therefore, the ratio is fair.

Yi.

V

which is confirmed by numerous changes in velocity, which showed close convergence of equality of works of VV VyV.

From here

-, v.

0

five

0

five

0

and the degree of anisotropy

2

, s

-vyv

Example. The degree of anisotropy of argilites with a layered core texture (42 mm obtained during drilling) is measured. The layers are angled to the core axis. For the study, choose a core column with a length of 108 mm with relatively parallel ends. On the lateral surface of the core with The fixing device, along the lamination in diameter, is installed opposite the other emitter and sensor and pulse detector and measure the time of passage of ultrasonic vibrations through the sample.

After the measurement is completed, the core is rotated 90 around the longitudinal axis and the measurements are repeated. The last measurement is carried out along the core axis. Based on the measurement base, the propagation speeds of the ultrasonic vibrations are determined.

According to the data obtained (V ;, 3.78);

 Yut

 2.54; power

V2 3.2 km / s) calculate the anisotropy of g

 1.76.

Claims (1)

Invention Formula The method of determining the degree of texture anisotropy of rocks, including the excitation: waiting for ultrasonic vibrations in a rock sample and measuring their propagation speeds in several directions, one of which coincides with the direction of the sample layering, which is different from that of, p. In order to increase productivity, a core is taken as a sample and measurements are performed on it in three mutually perpendicular directions, one direction coinciding with the longitudinal axis of the core, and the other two with its diameters, and determining the degree of texture anisotropy of the rock using the formula BUT t V, Where V, Vy-V the speed of propagation of ultrasonic vibrations along the diameter, coincides 1492053 core with stratification direction; ultrasonic propagation velocity along the second diameter; V is the speed of propagation of ultrasonic vibrating along the longitudinal axis of the core, FIG. 3 y