SU1670076A1 - Method of diamond cone drilling - Google Patents

Abstract

The invention relates to the mining industry and is intended for core diamond drilling. The goal is to increase the efficiency of the drilling method by reducing the cost of drilling. In the well on the drill pipe, the core set is lowered and the torque, axial load and the flushing agent are transferred to the diamond rock-destruction tool (APR). During the drilling process, the mechanical drilling rate (MSB) is recorded, the values of which regulate the indicated drilling parameters. Simultaneously with the registration, the SMEs register the rotational modes of the API, and establish a uniform mode of its rotation, in which the ratio of the angular velocity APRI ω _b to the specified angular velocity ω _{with a} rotator is ω _b / ω _with = 1. carry out its elimination at the well bottom. For this purpose, the uniform rotation mode of the API is transferred to the rotation mode with torsional vibrations, in which ω _b / ω _with ≥0. In this case, the translation is carried out periodically by changing the axial load on the API. The end of the polishing process is fixed by an increase in SME. 6 Il.

Description

The invention relates to the mining industry, in particular to the core-diamond drilling methods Skeakin,

The purpose of the invention is to increase the efficiency of the method by reducing the cost of drilling operations.

The essence of the proposal is as follows.

In the process of drilling a well, the working end of the tool destroys the rock by micro-cutting. As drilling practice shows, diamond polishing takes place, which

due to the diffusion of carbon atoms in diamond into the rock and the formation of a carbide layer on diamond, the hardness of which is much higher than the hardness of the rocks in the massif

The studies carried out with the help of high-speed filming, the work of a diamond tool while drilling a special block of optical glass that is similar in its properties to rocks of the VIII-IX category of drillability showed that, depending on the parameters of the drilling mode, three

Ltd

h |

about

rotational modes of the diamond rock-destroying tool, which are more characteristic (and

(ik.

mode

uniform rotation - Ri2 (1); auto-oscillation rotation mode (non-stop) - $ 2 (tti 0): torsional mode

self-oscillations (with stops) - Rv2 (771: - 0)

where dimensionless angular velocity

Od;

rotation;

hell is the crown angular velocity; Ok set the angular velocity of the rotator.

Based on the obtained research results, a diagram of the stability regions of different modes of rotation of the diamond tool in the coordinates n – p (Fig. 1) was constructed. where n is the frequency of rotation of the drill bit, rpm; p - axial load on the rock cutting tool, daN.

The region of existence of the rotation mode Ri21 is characterized by a uniform rotation of the diamond tool around the borehole axis, without stopping and strikes. Ensuring the uniformity of rotation allows, at constant parameters of the drilling mode, to increase the mechanical speed of the drill. In this mode, the hell and hell values are equal,

hell

therefore - 1. hell

The region of rotation Ri2 is very narrow and is characterized by high-frequency torsional vibrations, a drop in the mechanical drilling rate, and an increased wear of the rock-breaking tool matrix. In this mode, the angular speed of the instrument's rotation is lower than the angular velocity specified by the machine's rotator. Some rotation of the instrument is slowed down and accelerated. This leads to the formation of vibration on the instrument, but stopping at this

mode is missing, so - 0.

BUT:

The area of the Ri23 rotation mode is characterized by torsional vibrations with stops and blows of the tool on the face, increased tool wear and increased mechanical drilling speed. In this mode, shock loads are observed on the tool due to its stops at the bottom hole. The diamond tool stops are caused by the accumulation of compacted sludge under the end of the die and an increase in the braking moment due to this. At the moment when the tool stops, the angular velocity is hell 0, and the angular velocity hell is equal to the specified rotational speed. After stopping, the diamond tool rotates with acceleration up to a certain point and stops again. In practice, the stopping time and the turning time of a diamond tool are approximately equal. therefore

hell

ratio value

hell

0

During the drilling process, the axial load and torque are transmitted to the tool. Under the action of axial load, the drill string loses

stability and takes a wavy shape. At the moment the diamond tool stops, the continuously transmitted torque continues to twist the drill pipe. When this happens

a decrease in the half-length of the drill pipe, and this leads to a reduction in the length of the column and to the separation of the diamond tool from the bottom. When the tool is detached from the force of the bottom-hole friction, the tool gains acceleration due to the elastic properties of the drill pipe and torque. This increases the length of the half-wave of the drill pipe (as if the increase in the length of the column) and the tool with the impact

in contact with the bottom of a well. Such blows against a face occur with a frequency of up to 200-400 Hz. Such high frequency shock loads can expose polished diamonds at the bottom of a well without

change their properties.

Figure 2 shows the dependences Cd sh - f (a)}, where Cd is the abrasive coefficient of a rock – crown pair, and the specific volume work of destruction.

These dependences are derived from the results of research on the operation of diamond crowns in various modes of its rotation (Kd121 and KA123). They show

that the abrasiveness coefficient increases when operating in the Ri2 mode, and this, in turn, leads to the elimination of polishing of diamond tools.

The expression for Kd g I a0 tg--K ((a7 d0 + 2l / L D Osge is the blunting of a group of diamonds);

Cd

where b

a0 is the stiffness of the diamond – rock pair;

i is the number of diamonds group;

B is the width of the diamond face;

K - coefficient of proportionality between power and volume wear of diamonds;

n is the characteristic of the geometric shape of diamonds (the angle of the cut of diamonds); // - friction coefficient diamond - rock;

D is the average diameter of the crown;

Yaszh rock strength per cm tie.

Change the mode of rotation of the crown, i.e. the transfer from Ri2 to Ri2 with unchanged drilling mode parameters (FIG. 2) leads to an increase in the spacecraft. It can be seen from formula (1) that the coefficient of abrasiveness of the spacecraft increases with constant values of other quantities included in the formula, only with a decrease in the value of 60 (Fig. 3). those. in the Ri2 mode, sharpening of diamonds occurs with the formation of new cutting surfaces. This conclusion is confirmed by an increase in the mechanical drilling rate in the H123 mode (FIG. 4).

Thus, when polishing a diamond rock-cutting tool, it is proposed to periodically briefly enter it into the rotation mode Ri2 and transfer to the mode Ri; 1 by changing the axial load on the tool. The axial load changes are carried out until the optimum value of the mechanical drilling speed for the rocks being recovered is restored. The introduction of a diamond tool into the Ri2 rotation mode and the translation from this mode into the Ri2 rotation mode are proposed to be recorded during the drilling process using a torsional vibration sensor, the device of which is shown in Fig. 5,

FIG. 1 shows a diagram of areas of stable operation of a diamond tool; 2 shows the dependence of the spacecraft o) -f ((o) with different modes of rotation of the diamond tool, FIG. 3 shows the parameters of the protruding diamond at the end of the die; FIG. 4 shows the change in the drilling speed of the axial load and the limits of the rotational modes of the diamond 5 is a diagram of a torsional vibration sensor mounted in a core tube; FIG. 6 is a sectional view of FIG. 5;

The sensor contains a cylindrical body 1 rigidly fixed inside the core pipe 2. Inside the body 1, a cylindrical glass 3 is still located, which is suspended on the spring 4. In the gap between the inside of the body 1 and the outer surface of the glass 3, sealing elements 5 are installed. The fastenings of the housing 1 with the core pipe 2 are made with holes 6, and the housing 1 and the glass 3 have longitudinal slit-like coaxial holes 7 and 8.

In the course of drilling a diamond, a rock cutting tool (not shown) transfers the torque, the axial load and the flushing agent. During drilling of a well, the working end of the tool destroys the rock with the formation of a core column (not shown) by micro-cutting. In this case, the mechanical speed of drilling is recorded, the magnitude of which regulates the parameters of the drilling modes. Simultaneously with the recording of the mechanical drilling rate, the rotational modes of the diamond rock-destroying tool are recorded and an even mode of its rotation is established, which is the ratio of the angular velocity and the stress to the back of the tool.

(., D1 h

angular speed of rotation - - - 1 (R-2).

r / dv

The boundaries of the rotation modes (flash 1) are determined using a torsional vibration sensor. Installed in a set-up koponkop, the device of which is shown in Fig. 3. The torsional vibration sensor 1 is lowered into the well with the core pipe 2. The flushing fluid through the holes 6, 7 and 8 enters into the inner part of the core tube 2. When the diamond tool is operating in a uniform rotational Ri2 mode, the cup 3 suspended from the spring 4 rotates with the sensor body 2 at the same frequency. So kg with a uniform rotation of the diamond tool there are no torsional vibrations. then the holes 7 and 8 are aligned and the cm of the water indicating this is transmitted to the manometer of the mud pump (in our case, the pumping pressure does not increase as the flow resistance on the sensor does not increase)

A decrease in the mechanical drilling rate shows the fact of polishing the diamond tool's turret. To eliminate the polishing of diamonds, the uniform rotation of the diamond rock-cutting tool Ri2 is transferred to the rotation mode with torsional auto-oscillations, in which the ratio of the angular velocity of the tool to the set angle

rotational speed --- 0. Entry into

f fc

This mode is determined using a torsional vibration sensor (FIG. 5). The Ri2 mode is characterized by torsional vibrations in which the sensor cup 3 rotates around axis 0. Together with cup 3, aperture 8 is rotated relative to the watermark 7 and overlaps its settlement. Reducing the cross section of the holes 7 and 8 increases the pressure on the pump pressure gauge. So

As the cup 3 rotates around the axis O to the right and left relative to the hole 7, pressure surges are recorded on the pump manometer. These pressure surges indicate that the crown has entered the Ri23 rotation mode. The transfer of the diamond rock-destroying tool to the rotation mode Ri23 and the output to the rotation mode Ri21 are carried out periodically by changing the value of the axial load on the tool. Changes in the axial load on the diamond tool are carried out until the predetermined mechanical drilling speed for the rocks being recovered is restored. The axial load is controlled by the throttles of the hydraulic system of the drilling machine.

The end of the polishing tool elimination is recorded by an increase in the mechanical drilling rate, after which the diamond tool is placed in the Ri21 rotation mode. This mode is fixed according to the torsional vibration sensor readings.

Claims (1)

Claims method of diamond drill hole borehole, including the descent of the core set into the well on drill pipes, the transmission of torque, axial load and flushing agent to the diamond 0 rock cutting tool, recording the mechanical drilling speed, the magnitude of which regulates the specified drilling parameters, establishes the fact of polishing the diamond rock breaking tool by dropping the mechanical drilling speed and eliminating polishing of the diamond tool at the bottom of the well, characterized in that by reducing the cost of drilling, initially establish a uniform rotation mode for diamond rock-cutting tools a, in which the ratio of the angular velocity of the instrument to the specified angular velocity rotator with . fflt -1 and while reducing the fur the actual drilling rate, the elimination of polishing of the tool is carried out by transferring the uniform rotation mode of the diamond rock-cutting tool to the rotation mode with torsional vibrations, in which the ratio of the angular velocity of the tool to the specified angular velocity of the rotator at thirty This transfer is carried out periodically by changing the axial load on the rock cutting tool. 1000 - Physical SC And / -10 -g 1-Ю6 Fig 2 and / 2 n Fig.Z ex, "/ yQC ABOUT P, daN FIG B LA FIG. 6