RU2215113C1 - Rolling-cutter drilling bit - Google Patents

Abstract

FIELD: devices for well drilling. SUBSTANCE: rolling-cutter drilling bit includes legs with journals carrying cutting rollers with seals installed with help of radial and thrust journal bearings and rolling-cutter locking member with seals, and vessel with lubricant located on legs communicated with journal surface by means of two channels, whose one mouth is located in right-hand upper zone of cross-section of locking member and mouth of other channel is located in upper zone of periphery bearing. Journal surface in upper left-hand zone of cross-section of locking member is communicated through channel with surfaces of end bearing which are also communicated by channel with lower zone of journal surface in region of periphery bearing. Journal surface in region of locking member is made in form of cylinder with side nonclosed above and below curved grooves communicating in pairs with channels. Cylinder axis is parallel and located above journal axis. Locking member is made in form of prisms rectangular in cross-section, whose side surfaces facing journal have cylindrical surface with radius equaling journal radius. Prisms are spring-loaded to journal by flexible members movable in radial direction in rolling cutter recesses. EFFECT: increased service life of bearings of rolling-cutter drilling bit at its high rotation speed. 4 dwg

Description

 The invention relates to drilling equipment, namely to cone rock cutting tools for drilling wells.

 Known cone drill bit with bearings of type A containing radial and thrust sliding bearings and a locking element made in the form of an angular contact rolling bearing [1].

 The disadvantage of this bit is the low durability of the support due to the increased wear rate of its bearings by abrasive particles of cuttings that penetrate into the cavity of the support during the descent of the bit into the well and its drilling.

 Known cone drill bit with bearings type AU containing radial and thrust sliding bearings and a locking element made in the form of an angular contact rolling bearing. To prevent the penetration of abrasive fluid from the well into the supports, the latter are sealed with toroidal rubber rings installed at the base of the journal. The bit lubrication system is a compensation type system and is a cylindrical cavity filled with grease located in the upper part of the bit's paw and communicating with the support cavity by one channel. The cavity is sealed with a rubber dividing cap, which is held in it by means of a cap and a snap ring [2].

 The disadvantage of this bit is insufficient durability and the inability to work it out at high and high speeds, because at increased bit rotation speeds, high temperatures occur in the bearings, causing degradation of the lubricant and seal rubber, which leads to intensive wear of its elements and, ultimately, to the failure of the bit. The bit lubrication system allows the lubricant to be fed into the friction zone of bearings and seals, but does not provide intensive heat removal from the friction surfaces.

 The objective of the present invention is to increase the durability of the cone bit in conditions of high and high speeds by combining the functions of the locking elements of the supports.

 This problem is solved by the fact that in the roller bit, which includes paws with trunnions, on which are mounted using radial and thrust bearings and locking element of the roller cone with seals, containers with lubricant located on the feet, according to the invention, the container with lubricant in the foot communicates with the surface trunnions with two channels, the mouth of one of which is located in the upper right zone of the cross-section of the locking element, and the mouth of the second channel is located in the upper zone of the peripheral bearing, the trunnion surface in vertical The left side of the cross-sectional area of the locking element communicates with the channel with the surfaces of the end bearing, which, in turn, communicate with the lower zone of the trunnion surface in the area of the peripheral bearing, and the trunnion surface in the area of the locking element is made in the form of a cylinder with side arcs open at the top and bottom grooves pairwise communicating with the channels, while the axis of the cylinder is parallel and located above the axis of the journal, and the locking element itself is made in the form of prisms of rectangular cross-section, side The surfaces of which are facing the trunnion have a cylindrical surface with a radius equal to the radius of the trunnion, spring-loaded to the trunnion with elastic elements and having the ability to move in the radial direction in the grooves of the cutter.

 This implementation of the bit will solve the problem of increasing its durability, especially at high and high speeds due to the provision of intensive circulation of lubricant (oil) in the bearings and, accordingly, intensive heat removal from the friction surfaces. The lubricant is circulated in the bearings due to the inverted vane type pump, the prismatic plates of which at the same time serve as the locking elements of the bit supports. The lubricant circulating through the support of the bit, the channels in the trunnion, paw and reservoir in the upper part of the paw, is cooled in the latter and is again fed into the support.

 Comparative analysis with the prototype shows that the inventive bit is characterized in that the reservoir with lubricant located in the upper part of the paw communicates with the support by two channels, the mouth of one of which is located in the upper left zone of the journal in the area of the locking element, if you look at the journal with side of the end bearing, and the mouth of the second channel is located in the upper zone of the peripheral bearing, the surface of the journal in the area of the locking element is made in the form of a cylinder, the axis of which is located below the axis of the journal, and AMCOW member is a rectangular prism, a spring-loaded spigot povehnosti elastic elements.

 Thus, the inventive cone drill bit meets the criteria of the invention of "novelty."

 In FIG. 1 and .2 depict in section a part of the leg of a cone bit, where the main elements of the support are shown. In Fig. 1, a cross-section of a support with a cone in the area of the locking element shows the lubricating and lubricating channels, the shape of the arc grooves on the cylindrical surface of the journal, as well as the direction of eccentricity from the cylindrical surface of the journal in the region of the castle element relative to the axis of the journal. Figure 3 and figure 4 in section shows a diagram of the supply and removal of lubricant to the surfaces and from the surfaces of the bearings of the support.

 The bit contains a paw 1 with a pin 2, a cone 3 mounted on the pin on bearings including radial peripheral 4 and end 5 sliding bearings, an axial sliding bearing 6, a thrust bearing 7 and a lock sliding bearing 8. The sealing unit is a sealing element 9 in the form of a rubber O-rings The lock bearing is made in the form of a vane pump, in which the rotor is a roller cone 3. In the longitudinal grooves 10, the roller cones are mounted with the possibility of limited radial movement of the plate 11. The lateral surface of the plates 11 facing the journal has a cylindrical shape whose radius is equal to the radius of the journal, which ensures tight fit of the plates to the trunnion without wedge gaps. The plates fit snugly against the trunnion due to arched elastic plates 12. The trunnion surface in the region of the lock bearing 8 has the shape of a cylinder, the axis of which is located above the trunnion axis by the eccentricity e. On the lateral surfaces of the trunnion arc grooves 13 are made. Lubricant ( oil) during operation, the bit moves along the channels 14, 15, 16, 17, 18 and 19, as well as in the clearances of the end 5 and peripheral 4 sliding bearings.

 Longitudinal grooves 10 in the cone can be made using the end mill. To do this, it is necessary to bore the inner diameter of the cone in the region of the peripheral 4 sliding bearings. In this case, the role of one of the lateral surfaces of the lock bearing 8 will be played by a sleeve that is rigidly fixed in the cone, for example, due to the thread.

 The cone 3 on the axle 2 is mounted in the following sequence. First, a sleeve 20 is fixed in the cone. Then, elastic plates 12 and prismatic plates 11 are placed in the grooves 10. From the end of the cone 3, a sealing ring 9 is laid in it. After that, the cone 3 is pushed onto the pin 2, while at the moment of contact with the conical the collar of the thrust bearing 6, the prismatic plates 11 are moved apart in the radial direction in the grooves 10 of the cone. After passing the radial shoulder of the thrust bearing 6, the prismatic plates 11 will take their place, the elastic plates 12 will press them against the trunnion surface and provide a locking connection between the cutter and the trunnion.

 The work of the bit is considered using figures 1, 2, 3 and 4. When drilling, the bit is axially loaded against the bottom of the well, the torque is supplied to it by the downhole motor or from the rotor due to the drill pipe string. At the moment of transmission of the torque bit, its cones begin to rotate. When the cones rotate in the right zone of the locking element of the support (see Fig. 1), when viewed along the journal from the end bearing side, the space between two adjacent plates increases, a vacuum forms, oil is sucked from the lubricated containers through channels 14 and 15 (see Fig. 2), and in the left zone the volume between adjacent plates decreases and oil is injected into the channels 16 (see Fig. 3). Further, the oil through the gaps in the end bearing 5, the channel 17 (see Fig.3, 4), the gap in the peripheral bearing 4 and the channels 18 and 19 is returned to the tank with lubricant.

 When the bit is operating, the axial load to the roller cone in the direction from the borehole axis is perceived by the thrust bearing 6 and the thrust heel 7. The axial load to the roller cone in the opposite direction resulting from the reaction of the borehole wall is perceived by the prismatic plates of the locking element 8, the thrust collar of the pin 2 and the end face of the sleeve 20. The strength calculation for a bit with a diameter of 215.9 mm showed that the locking element works satisfactorily when creating an axial load on the bit up to 250 kN. This load significantly exceeds the performance rating for the bit of this size.

A verification calculation of the temperature in the bearings of the bearings of the proposed bit was made using the method [3]. For a bit with a diameter of 215.9 mm, the diameters of the lubricant-supplying (0.01 m) and lubricant-releasing (0.008 m) channels and the number of prismatic plates (12 pcs.) Were structurally assigned. As a lubricant, Cylinder 52 oil is used, which is the basis of SD1 bit lubricant [4, 5]. When rotary drilling and drilling by low-speed screw downhole motors on bits of this type give an axial load within 180.. .200 kN, and when drilling with a drill, the axial load does not exceed 120.. . 140 kN. The table shows the calculated temperatures of the bearings of the bit supports, which are determined with the above design parameters of the bit supports, axial loads and rotational speeds of the roller cutters within 1.75. . . 15 s ^-1 , which corresponds to a bit rotation frequency of 70 ... 600 rpm.

 The table shows that the temperature of the bearings of the bearings is 314 ... 316 K. This is 20 ... 30 K lower than the permissible oil temperature at the inlet to the oil pump [3].

Sources of information
1. Mokshin A. S., Vladislavlev Yu.E., Comm E.L. Roller bits. - M .: Nedra, 1971.- S. 131-132.

 2. International translator-guide "Roller bits" / Ed. V.Ya. Kurshenbaum and A.V. Torgashov. - M .: Oil and gas, 2000.- S. 15-16 and 59-61.

 3. Guzenkov P.G. A quick reference to the calculation of machine parts. - M.: Higher School, 1968 .-- 312 p.

 4. Fuels, lubricants, technical fluids. Assortment and application: Reference / I. G. Anisimov, K.M. Badyshtova, S.A. Bnatov and others; Ed. V.M.Shkolnikov. - M .: Publishing Center "Techinform", 1999.- 596 p.

 5. Konesev G.V., Mavlyutov M.R., Spivak A.I., Mulukov R.A. Lubricating effect of media in drilling technology. - M .: Nedra, 1993.

Claims (1)

 Roller cone bit, including paws with trunnions, on which are mounted with radial and thrust bearings and locking element of the roller cone with seals, lubricated containers located on the paws, characterized in that the lubricated tank in the paw communicates with the trunnion surface in two channels, the mouth of one of which is located in the upper right zone of the cross-section of the locking element, and the mouth of the second channel is located in the upper zone of the peripheral bearing, the trunnion surface in the upper left zone of the transverse the cross section of the locking element communicates with the channel end surfaces of the bearing, which, in turn, communicate with the lower zone of the surface of the journal in the region of the peripheral bearing, and the surface of the journal in the region of the castle element is made in the form of a cylinder with side arc grooves open at the top and bottom, pairwise communicating with channels, while the axis of the cylinder is parallel and located above the axis of the journal, and the locking element itself is made in the form of prisms of rectangular cross section, the side surfaces of which are facing a trunnion, have a cylindrical surface with a radius equal to the radius of the trunnion, the trunnion spring-loaded to spring elements and having the ability to move radially in slots cone.

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