RU2640445C1 - Method of ball-jet drilling of wells - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method of ball-jet drilling of wells consists in descent of rock-breaking balls on a bottom hole, feeding pressurized flushing fluid through a ball-jet-ejector drilling tool providing continuous circulation of balls, at that the distance between the tool and the bottom hole is maintained by reciprocation of the drilling tool. Acoustic signals are continuously recorded by means of acoustic oscillation sensor mounted on drill string of drill pipes, generated by balls as a result of their rebound from the bottom hole and collision with the drilling tool, and the distance between the drilling tool and the bottom hole is set by maximum values of amplitudes of acoustic signals.

EFFECT: increased efficiency of ball-jet drilling due to optimisation of adjustment process of the distance from tool to the bottom hole.

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Description

The invention relates to ball-hole drilling of wells and can be used for drilling exploration, technological, geothermal and other wells in solid rocks.

A known method of ball-hole drilling of wells [Uvakov AB Ball blasting. - M .: Nedra, 1969. - S. 6], selected as a prototype, in which continuous circulation of balls previously lowered to the bottom is carried out using a ball-ejector drill. At the same time, the distance between the projectile and the bottom of the well is maintained by pacing the projectile, during which during drilling, at certain intervals, it is lowered to the bottom and then raised to the required distance.

This method leads to intense deformation of the drill and balls under the action of axial load in contact with the bottom of the well.

The technical problem solved by the implementation of the proposed method is to increase the efficiency of ball-hole drilling by optimizing the process of controlling the distance from the projectile to the bottom of the well.

The method of ball-hole drilling, as in the prototype, consists in launching rock-cutting balls to the bottom, supplying flushing fluid under pressure through a ball-ejector drill providing continuous circulation of balls, while the distance between the shell and the bottom of the well is maintained by walking the drill.

According to the invention, using the acoustic vibration sensor mounted on the drill pipe string, the acoustic signals generated by the balls are continuously recorded as a result of their bounce from the bottom of the well and collision with the drill, and the distance between the drill and the bottom of the well is determined by the maximum values of the amplitudes of the acoustic signals.

The physical basis of the proposed method is the results of experimental studies conducted by the authors in laboratory conditions [Isaev E.D., Kovalev A.V., Aliev F.R. Experimental studies of technological parameters of the spherical-jet drilling mode // Collection of reports of the All-Russian scientific and technical conference with international participation "Problems of scientific and technological progress in well drilling" dedicated to the 60th anniversary of the department of well drilling. - Tomsk: Ed. TPU, 2014. - S. 68-83]. It has been established that with increasing distance between the diffuser of the projectile and the bottom of the well, the mechanical speed of ball-drilling decreases. High-speed shooting of the processes of ball movement showed [Isaev E.D. Investigation of the processes of ball blasting using high-speed video // Transactions of the XVIII International Symposium of Students and Young Scientists named after Acad. M.A. Usova "Problems of geology and subsoil development." - Tomsk: Ed. TPU, 2014. - S. 401-405], that in the area under the drill, clusters of balls are observed that cannot quickly leave this area. Moreover, with an increase in the distance between the projectile and the bottom of the accumulations more, which in turn leads to a decrease in the consumption of balls in the mixing chamber. The interaction of downward and reflected flows at a small distance leads to the fact that the balls bounced off the rock are faster sent to the annulus, and at a large distance, the falling balls bombard the balls bounced off the rock, which leads to their accumulations under the projectile.

In FIG. 1 shows a diagram of spherical drilling of the proposed method.

In FIG. Figure 2 shows the process of adjusting the optimal distance between the projectile and the bottom of the well and the corresponding values of the amplitude of the acoustic signals recorded by the acoustic vibration sensor during the well’s deepening: a) without lowering the drill, b) at the moment of jamming of the balls when lowering the projectile, c) at the moment of raising shell before resuming circulation of rock-breaking balls.

To carry out ball-hole drilling of wells, a string of drill pipes 1 (Fig. 1), which are equipped with centralizers 2, is connected at the bottom of a ball-jet-ejector drill, which is a cylindrical hollow body, in the upper part of which a nozzle 3 is made, a mixing chamber is located below 4 cylindrical with windows for the passage of rock-breaking balls, ending with a diffuser 5.

On the column of drill pipes 1 in the wellhead, an acoustic oscillation sensor 7 (D) is installed, to which a signal amplifier 8 (Y), an oscillographic prefix 9 (OP), for example PCLab2000, and a control system 10 (SU) are connected in series.

As a sensor of acoustic vibrations 7 (D), a piezoresistive accelerometer can be used to measure long transient processes and short-term shock effects.

The control system 10 (SU) is a bit feed regulator, which is supplied with modern drilling rigs.

At the bottom of the well, a portion of balls 6 is poured, the drill is lowered, washing liquid is pumped. The working fluid supplied to the drill is accelerated in the nozzle 3 and at the exit from it flows out at a high speed into the mixing chamber 4. At the same time, a rarefaction zone is formed in the space between the nozzle 3 and the mixing chamber 4. Due to the rarefaction, the working fluid is sucked in together with the suspended balls 6 from the annulus through the windows for the passage of the rock-breaking balls of the mixing chamber 4. Then the two-phase mixture passes through the mixing chamber 4 and the diffuser 5 and hits the rock, causing destruction. In the process of circulation in the bottomhole zone of the well, balls 6 constantly interact with a drill, in which longitudinal waves of deformation are formed as a result of their bounce from the bottom of the well. The forming elastic vibrations are transmitted along the drill pipe string 1 at the wellhead, where they are recorded by the acoustic vibration sensor 7 (D), amplified by an amplifier 8 (Y) and sent through an oscillographic prefix 9 (OP) to the control system 10 (SU), which transmits control action of the drill based on the received signal.

After drilling a well with a diameter of 46 mm in a granite block (flow rate of flushing fluid was 2 l / s) and driving an interval of 5 cm, a regime was established that corresponded to the maximum value of the amplitude of the acoustic signal 12-18 conv. units (Fig. 2, a)), then the drill was briefly lowered until the balls 6 jammed (Fig. 2, b)), accompanied by a decrease in the amplitude of the acoustic signal to 5-10 conv. units registered by the acoustic vibration sensor 7, and raised until the resumption of their circulation (Fig. 2, c)), accompanied by an increase in the amplitude of the signal to 12-18 srvc. units, which testified to the achievement of the optimal distance between the drill and the bottom of the well Rсз.

Thus, the determination during the drilling process of the value of the amplitude of the acoustic signals allows you to quickly select the most effective drilling mode.

Claims (1)

The method of ball-hole drilling, which consists in launching rock-cutting balls to the bottom, supplying flushing fluid under pressure through a ball-ejector drill providing continuous circulation of balls, while the distance between the shell and the bottom of the well is maintained by walking the drill, characterized in that The acoustic vibration sensor installed on the drill pipe string continuously records the acoustic signals generated by the balls as a result of their rebound from the bottomhole importance and collisions with the drill, and the distance between the drill and the bottom of the well is set by the maximum values of the amplitudes of the acoustic signals.

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