RU89170U1 - DRILLING EQUIPMENT - Google Patents

Abstract

1. A drill for drilling wells with high-voltage pulsed discharges, consisting of a drill bit with high-voltage and grounded electrodes, a drill pipe string, as well as a source of high-voltage pulses and its charger, which are located above the drill bit, characterized in that the source of high-voltage pulses and charger the device is placed in a container, loosely worn on a drill pipe string above the drill bit. ! 2. The drill according to claim 1, characterized in that the outer surface of the container is made with longitudinal flushing channels, the width and depth of each of which is not less than the largest interelectrode gap between adjacent high-voltage and grounded electrodes. ! 3. The drill according to claim 1, characterized in that a load-carrying cable is placed along the drill pipe string, which is mechanically connected to the container, and a charger is electrically connected to it. ! 4. The drill according to claim 1, characterized in that the drill pipe string is made in the form of a umbilical, on which the container is freely mounted. ! 5. The drill according to claim 1, characterized in that a directional pipe is placed between the drill pipe string and the container with the source of high voltage pulses and the charger.

Description

The utility model relates to technical means for drilling wells and drilling holes using high-voltage pulsed discharges developing in rock, and can be used in the oil and gas industry for drilling wells several thousand meters deep, including in the seabed, as well as in the mining industry for sinking wells in hard rocks in hundreds of meters deep shafts.

Known electric pulse drill (copyright certificate SU No. 730022; IPC 4 E21s 37/18; publ. 12/30/1987, bull. No. 48), consisting of a drill bit, drill string and high voltage input, and inside the drill string above the drill bit is a generator high voltage pulses connected to a conductive system, the upper end of which is passed through a high voltage input.

The main disadvantages of this drill are: 1) the need to supply a constant high charging voltage to the drill from the surface of the drill, which makes increased demands on the insulation of the conductive system, and 2) the limited volume in which the generator of high-voltage pulses is located, the inner diameter of the drill string.

The first drawback is eliminated in the closest to the proposed design features and the achieved positive effect of the drill for drilling by electric pulse discharge (patent for invention RU No. 2319009; IPC E21c 37/18 (2006.01), IPC E21B 7/00 (2006.01), publ. March 10, 2008, Bulletin No. 7), consisting of a drill bit and a drill pipe string connected in series, as well as a high-voltage pulse source located above the drill bit directly in the drill pipe string and a source charger voltage pulses located above this source. In addition, the source of high-voltage pulses and the charger are equipped with a jacket, which forms a channel for the outgoing flow of flushing fluid between the drill pipe string and the jacket.

One of the main drawbacks of this drill is associated with the limited volume in which the source of high-voltage pulses and its charger are located, the inner diameter of the drill pipe string, which does not allow the use of larger and more reliable high-voltage equipment or more powerful pulse sources. In addition, for maintenance, repair or replacement of the charger and the source of high-voltage pulses, it is necessary to lift the entire drill from the well to the surface.

The technical result of the proposed solution is to increase the volume (without changing the length) in which the source of high-voltage pulses and its charger are located. In a drill for drilling wells with submersion of a source of high-voltage pulses and a charger, together with the drill bit, the cross-sectional area of the container in which they are placed is 15-20% larger than the corresponding prototype area (the volume is also increased by the same percentage). When drilling in the seabed or in deep trunks, the design of the proposed shell allows you to increase this area several times. Such an increase in the area, and hence the volume, makes it possible to use more reliable sources of high voltage pulses and chargers or to increase their output parameters, as well as reduce the time spent on their maintenance, repair or replacement, because created the ability to lift the container to the surface without lifting the drill pipe string and drill bit.

Moreover, the transformation of the drill is not in the elementary placement of the source of high voltage pulses and its charger outside the drill pipe string. Suffice it to say that in all known shells for drilling with high-voltage pulse discharges, high voltage is supplied to the internal elements (electrodes) of the drill bits (crowns), in the proposed shell to the external. Non-traditional in it are some other electrical solutions.

The specified technical result is achieved by the fact that in a drill for drilling wells with high voltage pulsed discharges, consisting of a drill bit with high voltage and grounded electrodes, a drill pipe string, as well as a source of high voltage pulses and its charging device, which are located above the drill bit, according to the proposed solution , the source of high-voltage pulses and the charger are placed in a container, freely dressed on a drill pipe string above the drill bit.

It is advisable to carry out the outer surface of the container with longitudinal flushing channels, the width and depth of each of which is not less than the largest interelectrode gap between adjacent high-voltage and grounded electrodes.

It is also advisable to place a load-carrying cable along the drill pipe string, which is mechanically connected to the container, and a charger is electrically connected to it.

In addition, it is advisable to carry out the drill pipe string in the form of a umbilical, onto which the container is loosely mounted.

It is also advisable to place a directional pipe between the drill pipe string and the container with the source of high voltage pulses and the charger.

The specific implementation of the proposed utility model is illustrated by five figures. Figure 1 shows a longitudinal section of a drill, figure 2 shows its cross section in the container area (for demonstrating longitudinal flushing channels), figure 3 shows a cross section of the shell along the core insulator, figure 4 shows a section of the bottom-hole ends of high-voltage and grounded electrodes. The main difference between FIG. 5 and FIG. 1 is that, in FIG. 5, the drill is further provided with a direction pipe attached to the base plate. The drill (Fig. 1) contains a drill bit 1 attached to the string of drill pipes 2. The main elements of the drill bit 1 are (Fig. 1 and Fig. 4) high-voltage 3 and grounded 4 electrodes, as well as the core insulator 5. In the central part the crown insulator 5 (FIG. 3) has internal channels 6 for a downward flow of washing liquid. The core insulator 5 (FIG. 1) holds the rod support 7 (FIG. 1) of grounded electrodes 4 tightly seated therein. The electrical connection between this support 7 and the drill pipe string 2 is made by a sliding contact 8. A container 9 is installed above the drill bit 1, which is free worn on a drill pipe string 2. A container 9 contains a source of high-voltage pulses 10 and its charger 11. The container 9 is provided with a cover 12 through which a load-carrying cable 13 is passed, which is mechanically connected to the container 9, and electrically to the charging construction 11. High-voltage contact 14 is designed to transfer high-voltage pulses from the source of high-voltage pulses 10 to the drill bit 1. On the upper end of the drill pipe string 2, a headpiece 15 is screwed to which the discharge fitting 16 is attached. To ensure the transfer of sludge and gaseous products to the surface, formed during the development of discharges, the container 9 is made with several longitudinal flushing channels 17 (figure 2).

In Fig. 5, the same drill, which is shown in Figs. 1 ÷ 4, is shown while drilling in the sea 18 with a semi-submersible drilling rig 19 in the seabed 20. For the removal of cuttings to the surface (on the deck of a semi-submersible drilling rig 19) between the container 9 and a drill pipe string 2, a directional pipe 21 is located, the lower end of which is attached to the base plate 22, and the upper one, like that of the drill pipe string 2, goes to the deck of the semi-submersible installation 19. The high-voltage cable 23 serves to transmit high-voltage pulses from their source 10 to high voltage electrodes 3 of the drill bit 1. Similarly, the device of the drill during drilling of wells in the trunks, which can significantly increase the efficiency of the subsequent penetration of the trunks in strong rocks, for example, by drilling and blasting.

The outer diameter of ShKh15 steel and the tested drill bit 1 (Fig. 1) is 360 mm. Interelectrode gaps between adjacent high-voltage 3 and grounded 4 electrodes (figure 4) are 40-60 mm The outer diameter of the container 9 (Fig. 1) is chosen equal to the diameter of the drill bit 1. Due to the fact that the depth of the spall funnel formed during the development of a high-voltage pulse discharge in the rock is 30% of the interelectrode gap (this also applies to the development of discharges in the walls of the well), the outer diameter of the container 9 can theoretically be increased by a maximum of 36 mm - with gaps between the high-voltage 3 and grounded 4 electrodes (Fig. 4) along the outer circumference of 60 mm. The inner diameter of the drill pipe string 2 (FIG. 1) is 60 mm. The container 9 and the cover 12 are made of polyethylene. As a load-carrying cable 13, a load-carrying cable for geophysical work in deep wells was used. The breaking strength of these cables is up to 70 kN.

The work of the drill. Drill set on the bottom of the well. Through the discharge fitting 16 (Fig. 1), drilling fluid (diesel oil) is supplied to the drill pipe string 2, which flows through the internal channels 6 (Fig. 3) of the core insulator 5 to the drill bit 1, from where it goes through the annulus, including through longitudinal washing channels 17 (figure 2) of the container 9, rises to the surface. Then (Fig. 1) an alternating voltage of 380 V is supplied via the load-carrying cable 13 to a charging device 11, from which a direct voltage of 35 kV is supplied to a source of high-voltage pulses 10, and the latter converts it to a pulse voltage. Impulses with an amplitude of 350 kV from this source through high-voltage contact 14 go to high-voltage electrodes 3. In the bottomhole zone between high-voltage 3 and grounded 4 electrodes with a frequency of 5 imp / s in the rock, high-voltage pulse discharges develop, breaking off and partially destroying rock particles forming a slurry that is carried to the surface by flushing fluid. Experimental drilling was carried out in coarse granite blocks with a speed, like the prototype, of about 2 m / h. But in the proposed drill by increasing the cross-sectional area of the container 9 (without changing the length), and hence the volume in which the charger 11 and the source of high-voltage pulses 10 are placed, the reliability of these blocks increases by about 2 times. Moreover, for troubleshooting, for preventive examinations, they do not lift the entire drill string to the surface and do not disassemble it, but screw the cap 15 off the drill pipe string 2 and use only the load-carrying cable 13 to lift the container 9 to the surface and replace it with another container in which serviceable charger 11 and a source of high voltage pulses 10, which can significantly increase the time of clean drilling.

As described above, to quickly lower or raise the entire drill string without unscrewing the drill pipe string 2 on sections (candles), it is made in the form of a umbilical cable, on which container 9 is loosely mounted. A winch, on the drums of which a drill pipe string 2 and a load-carrying cable are wound 13, figure 1 ÷ 5 is not shown.

When drilling at sea 18 (Fig. 5) from a semi-submersible drilling rig 19, before the drill pipe 2 is supplied with drilling fluid 2, a directional pipe 21 is placed between this string 1 and the container 9, and the drilling fluid rises to the surface between the drill pipe string during drilling 2 and a directional pipe 21. Since wells are drilled from semi-submersible units 19 in the seas up to several kilometers deep, the proposed design of the drill allows the source of high-voltage to be brought closer to the drill bit 1 pulses 10 and charger 11 (the value of the depth of the sea). However, there are no significant restrictions on the volume of the container 9 in which these blocks are placed, which makes them more reliable in operation. At the same time, conditions were created for their rapid launching and lifting with a drilling tool installed at the bottom of the well without lowering or lifting the crown 1 and drill pipe string 2, which increases the time of clean drilling.

Claims (5)

1. A drill for drilling wells with high-voltage pulsed discharges, consisting of a drill bit with high-voltage and grounded electrodes, a drill pipe string, as well as a source of high-voltage pulses and its charger, which are located above the drill bit, characterized in that the source of high-voltage pulses and charger the device is placed in a container, loosely worn on a drill pipe string above the drill bit. 2. The drill according to claim 1, characterized in that the outer surface of the container is made with longitudinal flushing channels, the width and depth of each of which is not less than the largest interelectrode gap between adjacent high-voltage and grounded electrodes. 3. The drill according to claim 1, characterized in that a load-carrying cable is placed along the drill pipe string, which is mechanically connected to the container, and a charger is electrically connected to it. 4. The drill according to claim 1, characterized in that the drill pipe string is made in the form of a umbilical, on which the container is freely mounted. 5. The drill according to claim 1, characterized in that a directional pipe is placed between the drill pipe string and the container with the source of high voltage pulses and the charger.