RU2100559C1 - Tool for well drilling - Google Patents

Abstract

FIELD: tools for well drilling. SUBSTANCE: tool includes drill pipe string whose lower part is connected to turbodrill body by means of sub, and drill bit connected to turbodrill shaft. Turbodrill shaft is secured in turbodrill body with the help of axial and radial bearings. Turbodrill working members include: bladings of turbine pressure stage; turbodrill axial and radial bearings fixed in its body with the aid of tensioned threaded sub. Connected to sub lower end is diamond drill crown. Drill bit is located inside body of diamond drill crown. Outside drill bit diameter is larger than inside diameter of tensioned threaded sub by 0.003-0.40 m. EFFECT: higher efficiency. 1 dwg

Description

 The invention relates to the field of tools and devices used for drilling oil and gas wells, in particular to technical means for turbine drilling.

 Known tools with which attempts were made to carry out stepwise destruction of the bottom of the well, with the aim of reducing energy consumption for the destruction of rocks and increase the mechanical speed of penetration (ed. St. USSR N 135845).

 In the tool, made according to this copyright certificate, the expander of the pilot (leading) shaft is rotated by the turbodrill body, and the pilot (leading) bit is rotated by the rotor of the drilling rig through the drill pipe string and the axis of the turbodrill rotating by the drill pipes, to the lower end of which the pilot bit is connected. It was assumed that the power sold on the pilot bit destroys the relatively small surface of the bottom of the well. At the same time, the pilot expander, destroying the upper flange of the stepped face, not only drills, but also rolls off this flange in large pieces, which intensifies the mechanical speed of penetration.

 However, in the process of industrial testing of this technical innovation, it was found that the expander’s rotational drive with the help of a turbodrill housing has a number of significant and practically insoluble drawbacks.

 The main ones are as follows.

 1. The tool expander is significantly more moment-intensive than the chisel. The turbodrill cannot provide the necessary torque values on a rotating casing.

 2. When the expander is underloaded (at modes close to the idle speed of the turbodrill), the expander cone bearings quickly fail, which leads to the need to quickly replace an expensive expander.

 The implementation of the expander in the form of a diamond crown is impossible, since its energy intensity is much greater than the energy intensity of the cone expander.

 3. The rotation of the turbodrill body relative to its axis, attached to the drill pipe string, requires a reliable seal in its upper part. To date, such an oil seal has not been created.

 4. The rotation of the turbodrill casing leads to its quick turning-off in diameter and the need for replacement, since a significant part of the drilled rocks has high abrasiveness, its rotation frequency is very high (600-1200 rpm). At the same time, the protection of a long body from wear by applying carbide coatings is not effective from an economic point of view.

 However, the small amount of experiments that were carried out in the field of stepwise destruction of the bottom of the well convincingly showed that from an energy point of view (increasing the efficiency of destruction of the rock of the bottom of the well), this case is very promising.

 The closest analogue of our invention is a known device that implements a method of drilling wells (ed. St. USSR N 794139) and consisting of a turbodrill, to which a bit is attached to the lower part of the body, inside which another bit is attached, attached to the turbodrill shaft. In this case, the turbo-drill body connected to the drill string, together with the outer bit, rotates from the rotary table of the drilling rig, and the inner bit rotates in the opposite direction by the turbo-drill shaft.

 By concentrating in itself a significant number of necessary and general design features, this invention does not solve the problem posed by us. Significant reduction in energy costs per unit volume of drillable rock. Placing the rock-cutting elements of the cones of the outer and inner chisels in one plane and depositing on the bearings of the cones of the outer chisel of a large radial dimension automatically significantly reduces the diametric dimension of the inner chisel, and therefore reduces its performance. Attempts to design such a system in a borehole diameter of 295.3 mm did not yield a positive result. The more complicated the situation with smaller diameters.

 The drawing shows a tool for drilling. In the housing 1 of the turbodrill, which is connected to the drill string by means of a sub 2, the stator elements of the axial support 4, the stator elements of the radial bearings 5 and the stator blade crowns 6 of the turbine pressure stage are fixedly fixed. Their fixed fastening in the housing of the turbo-drill 1 is provided by means of a threaded threaded sub 7, to the lower end of which a diamond drill bit 8 is attached to the thread.

 On the shaft 9 of the turbodrill, the rotor elements 11 of the axial support are fixedly fixed with a tightening nut 10; rotor elements 12 of radial bearings and rotor blade crowns 13 stages of turbine pressure. In the upper part of the shaft 9 of the turbo-drill there is an internal cavity 14, which hydraulically communicates with its upper end with the internal cavity of the sub 2 and the internal cavity of the drill string 3. Through the windows 15, the internal cavity 14 of the shaft 9 of the turbo-drill is hydraulically connected with the space inside the turbo-drill housing 1, in which stator 6 and rotor 13 blade crowns of turbine pressure steps and stator 5 and rotor 12 elements of radial bearings.

 The rotor elements 11 of the axial support are separated from the rotor blade crowns 13 of the turbine pressure stages by means of a lantern 16, in which there are windows 17 hydraulically communicating windows 15 and the internal cavity 14 of the turbo-drill shaft 9, with a space inside the turbo-drill housing 1 in which the blade-wreath stages are placed turbine pressure and turbo-drill radial bearings.

 In the lower part of the shaft 9 of the turbo-drill there is an internal cavity 18, which is hydraulically connected to the sub-turbine space 19 of the turbo-drill housing 1 by means of windows 20.

 In the lower part of the shaft 9 of the turbodrill, a cone bit 21 is attached to the thread, the outer overall diameter of which is 0.003-0.040 m larger than the inner diameter of the tension threaded sub 7.

 The lower part of the shaft 9 of the turbodrill, to which the bit 21 is attached, protrudes beyond the inner cylindrical surface of the sub 7 by a value of 100-300 mm, which makes it possible to replace the bit 21 with the help of drilling machine keys. The rock-breaking surface of the diamond crown 8 in its inner (core-forming) diameter is 2-20 mm larger than the outer (overall diameter) of the bit 21, and in the outer bore-forming diameter is 20-80 mm larger than the outer diameter of the tension threaded sub 7.

 In this case, the core-forming surface of the diamond crown 8 stands (in axial height) for the rock-forming surface of the bit 21 by the maximum possible value from a technological point of view.

 Work tool for drilling.

 Drilling is carried out while the mud pump is running. In this case, the drill string 3, the turbo-drill body 1 and the diamond crown 8 attached to the sub 7 rotates by the rotor of the drilling rig with a frequency of 60-250 rpm.

 Flushing drilling fluid from the inner cavity of the drill string 3 enters the inner cavity 14 of the shaft 9 of the turbo-drill and then through the windows 15 of the shaft and the window 17 of the lamp 16 enters the space inside the housing 1 of the turbo-drill, in which the blade crowns of the turbine pressure stages and its radial bearings are located.

 The rotor blade crowns 13 of the turbine rotate the turbodrill shaft 9 and, accordingly, rotate the bit 21 connected to the lower end of the shaft 9. The flushing fluid spent in the blade crowns of the turbine pressure steps enters the turbine space 18 of the turbodrill housing 1 and then through the windows 20 into the internal cavity 18 shaft 9 of the turbodrill. Through the internal cavity 18 of the shaft 9, the flushing fluid enters the bit 21. Next, the flushing fluid through the inner cavity of the diamond crown 8 enters its rock-cutting and core-forming surface, and then into the space behind the turbodrill body 1 (annular space of the well). Diamond drill bit 8 is performed with a minimum radial width of the rock-cutting-core-forming surface, which provides the best conditions from the point of view of increasing the mechanical speed of the wellbore.

 Bit 21 runs on a core, destroying it and not resting against the cones of the cones against the wall of the well (as is the case with conventional rotary or turbine drilling). This circumstance reduces the energy intensity of the bit by several times, which makes it possible to provide the turbodrill with its rotation frequency that falls within the range of values from 250 to 600 rpm and contributes to its high failure resistance.

 Diamond crown 8, which has a very high energy intensity, allows you to realize the best quality of rotary drilling with an almost unlimited supply of torque spent on the smallest possible surface of the core-forming face.

Claims (1)

 A tool for drilling wells, including a drill string, to the lower part of which a turbodrill is attached, on the shaft of which an internal drill bit is mounted, located inside the external drill bit, characterized in that the external drill bit is made in the form of a diamond core connected to the lower end of the turbodrill body by lower tension threaded sub, while the overall size of the inner bit is 0.003 0.040 m greater than the inner diameter of the lower tension threaded sub.