RU2298074C1 - Cone drilling bit (variants) - Google Patents

Abstract

FIELD: rock-cutting tools, particularly cone bits for well drilling.

SUBSTANCE: drilling bit comprises body with conical nipple having inner channel and outer thread. The body is provided with flushing channels and grooves made in inner surface. Drilling bit also has legs with cutters fixedly secured in body grooves. Outer diameter of thread provided on minor base of drilling bit nipple cone d is related to outer (nominal) drilling bit diameter D as d/D=0.2-0.6. Drilling bit made in accordance with the second embodiment comprises body with conical nipple having inner channel and outer thread. The body also has flushing channels and grooves created in outer surface thereof and legs with cutters fixed in body grooves. Formed inside the nipple are n channels, wherein n≥2. Outer diameter of thread provided on minor base of drilling bit nipple cone d is related to outer (nominal) drilling bit diameter D as d/D=0.2-0.6.

EFFECT: increased drilling bit efficiency, reliability and manufacturability.

3 cl, 2 dwg

Description

The invention relates to a rock cutting tool, and in particular to cone bits for drilling wells.

As the closest analogue (prototype) to both proposed options in terms of technical nature and the achieved result is a cone drill bit containing a body with a conical nipple with an internal channel and a thread made on the nipple, flushing channels and grooves on the outer surface and paws rigidly fixed in the grooves of the body with cones (RF Patent No. 2146754, publ. 20.03.2000).

Using in the prototype the value of d - the diameter of the large base of the conical nipple of the drill bit in the ratio d / D, where D is the outer (nominal) diameter of the drill bit, does not allow to obtain the required accuracy of the connecting thread of the drill bit. In this regard, it becomes difficult to provide one of the main parameters of the locking threaded joint of the drill bit - guaranteed thread tightness and, accordingly, increasing the reliability of the bit as a whole.

The technical result of the claimed invention is to increase the reliability of the bit and the manufacturability of its manufacture by using in the proposed technical solution the value of d - the outer diameter of the thread of the small base of the cone of the drill bit nipple in the ratio d / D, where D is the outer (nominal) diameter of the drill bit. In addition, the use of d in the d / D ratio increases the accuracy of the thread of the drill bit nipple, which, in turn, increases the reliability of its fastening with the drill pipe string, due to the guaranteed tightness of the threaded connection.

In addition, the technical result is to increase the efficiency of the drill bit by forming the inner channel of the bit nipple to create better conditions for the passage of washing fluid or air-water mixture through it by performing the following ratio:

d / dvn = 0.7-17.0,

where d is the outer diameter of the thread of the small base of the cone of the nipple of the drill bit;

dвн - diameter of a circle inscribed in the internal channel of the nipple located in the main plane of the thread of the drill bit nipple.

To ensure uniform distribution of the total flow of flushing fluid or air-water mixture passing through the internal channel of the drill bit nipple, and the targeted supply of the agent to the hydraulic monitor nozzles and into the bearing units of the drill bit cones, the internal channel of the nipple may consist of n channels, where n≥2.

If there are several channels in the nipple

where d ₁ , d ₂ , ..., d _n are the diameters of the circles inscribed in each of the internal channels of the nipple, located in the main plane of the thread of the drill bit nipple.

The achievement of the technical result according to the first embodiment is ensured by the fact that in the roller cone bit containing a body with a conical nipple with an internal channel and a thread made on the nipple, flushing channels and grooves on the outer surface and paws with cones rigidly fixed in the grooves of the body, the outer diameter of the thread the small base of the cone of the drill bit nipple d is connected with the outer (nominal) diameter of the drill bit D by the ratio d / D = 0.2-0.6. It has been experimentally established that the specified range allows to increase the reliability of the drill bit by providing higher reliability of the threaded connection, without increasing the strength characteristics of the connection due to the increase in the size of the nipple and its metal consumption.

As a result of experimental work, it was found that with a d / D ratio of more than 0.6, the reliability of the connection does not significantly increase, but the overall dimensions of the nipple part and, accordingly, the metal intensity of the nipple increase sufficiently due to an increase in the thickness of its walls. When the d / D ratio is less than 0.2, the reliability of the threaded joint significantly decreases due to a decrease in its bearing capacity due to a decrease in the overall dimensions of the nipple and, in particular, a decrease in the thickness of its walls.

The outer diameter d of the thread of the small base of the drill bit nipple cone is connected with the diameter dвн of the circle inscribed in the inner channel of the nipple of the circle located in the main plane of the thread of the drill bit nipple, with the ratio d / dвн = 0.7-17.0.

The achievement of the technical result according to the second embodiment is ensured by the fact that in the roller cone bit containing a body with a conical nipple with an internal channel and a thread made on the nipple, flushing channels and grooves on the outer surface and paws with cones rigidly fixed in the grooves of the body, made inside the nipple n channels, where n≥2, the outer diameter of the thread of the small base of the cone of the drill bit nipple d is connected with the outer (nominal) diameter of the drill bit D by the ratio d / D = 0.2-0.6.

The outer diameter d of the thread of the small base of the cone of the drill bit nipple is connected with the diameter dвн of the circle inscribed in the inner channel of the nipple of the circle located in the main plane of the thread of the drill bit nipple, with the ratio d / dвн = 0.7-17.0,

,Where

,

where d ₁ , d ₂ , ..., d _n are the diameters of the circles inscribed in each of the internal channels of the nipple, located in the main plane of the thread of the drill bit nipple

Figure 1 shows a General view of the drill bit in the context of the first embodiment.

Figure 2 shows a General view of the drill bit in the context of the second embodiment.

The first embodiment of the bit.

The drill bit contains a housing 1 with a conical nipple 2 and a connecting conical thread 3 applied thereon, channels 4 for flushing (purging) and grooves 5 on the outer surface, in which, for example, the plug sections consisting of legs 6 are rigidly fixed by welding on pins 7 of which, by means of bearings 8, cones 9 with rock cutting elements 10 are installed in the form of milled teeth or carbide teeth. In the nipple 2, the inner channel 11 is made.

The outer diameter of the thread 3 of the small base of the cone of the nipple 2 of the drill bit d is connected with the outer (nominal) diameter of the drill bit D by the ratio d / D = 0.2-0.6.

The outer diameter d of the thread 3 of the small base of the cone of the drill bit nipple 2 is connected with the diameter d of the circle inscribed in the inner channel 11 of the nipple 2 located in the main plane of the thread 3 of the drill bit nipple 2, with the ratio d / dv = 0.7-17.0.

Drill bit works as follows. The layout of the bottom of the drill string (BHA) is formed so that the last element of the BHA to be attached to the drill stand is the drill bit. In this regard, the highest requirements are imposed on the reliability of its threaded connection. When connecting the bit to the drill string, a guaranteed tightness must be ensured by strictly observing the parameters of the connecting thread 3. Therefore, introducing into the proposed technical solution a specific parameter of the connecting thread 3 of the bit, namely the outer diameter of the thread 3 of the small base of the cone of the nipple 2 of the drill bit d, will ensure the required degree of reliability of fastening the drill bit. Under the action of axial load and torque, rock-cutting elements 10 of the bit are introduced into the rock and destroy it. In this case, the flushing fluid or the air-water mixture injected under pressure through the drill pipe string through the internal channel 11 and channels 4 of the bit carries the destroyed rock from the bottom to the surface. At the same time, the flushing fluid or the air-water mixture cools the rock-cutting elements 10 and the bearing units of the cone bits of the drill bit.

The efficiency of the bit is ensured largely due to the intensive removal from the bottom of the drilled rock (sludge). This process depends on providing the required conditions for flushing or purging.

The best conditions for the passage of the washing liquid or air-water mixture are provided by certain requirements for the formation of the inner channel 11 of the nipple 2 bits. It should be noted that, as a rule, the nominal size of the thread of the bit nipple is set in its main plane (see Fig. 1, 2), which is perpendicular to the axis of the thread of the bit; it also measures the dimensions of the outer, middle and inner diameter of the tapered thread.

Most often, one inner channel 11 of the nipple 2 of the bit is made in the main plane of the thread 3, but there can be several. They can be performed as a regular shape in the form of a cylinder, a forward or reverse cone, and irregular shape.

The second embodiment of the bit

The drill bit contains a housing 1 with a conical nipple 2 and a connecting conical thread 3 applied thereon, channels 4 for flushing (purging) and grooves 5 on the outer surface, in which, for example, the plug sections consisting of legs 6 are rigidly fixed by welding on pins 7 of which, by means of bearings 8, cones 9 with rock cutting elements 10 are installed in the form of milled teeth or carbide teeth. In the nipple 2, internal n channels 11 are made, where n≥2.

The outer diameter of the thread 3 of the small base of the cone of the nipple 2 of the drill bit d is connected with the outer (nominal) diameter of the drill bit D by the ratio d / D = 0.2-0.6.

The outer diameter d of the thread 3 of the small base of the cone of the drill bit nipple 2 can be connected with the diameter d of the circle inscribed in the inner channel 11 of the nipple 2 located in the main plane of the thread 3 of the drill bit nipple 2, by the ratio

d / dvn = 0.7-17.0,

,Where

,

where d ₁ , d ₂ , ..., d _n are the diameters of the circles inscribed in each of the internal channels of the nipple, located in the main plane of the thread of the drill bit nipple.

Drill bit works as follows. The layout of the bottom of the drill string (BHA) is formed so that the last element of the BHA to be attached to the drill stand is the drill bit. In this regard, the highest requirements are imposed on the reliability of its threaded connection. When connecting the bit to the drill string, a guaranteed tightness must be ensured by strictly observing the parameters of the connecting thread 3. Therefore, introducing into the proposed technical solution a specific parameter of the connecting thread 3 of the bit, namely the outer diameter of the thread 3 of the small base of the cone of the nipple 2 of the drill bit d, will ensure the required degree of reliability of fastening the drill bit. Under the action of axial load and torque, rock-cutting elements 10 of the bit are introduced into the rock and destroy it. The flushing fluid or the air-water mixture injected under pressure through the drill pipe string through the internal channels 11 and channels 4 of the bit carries the destroyed rock from the bottom to the surface. In this case, to ensure uniform distribution of the total flow of flushing fluid or air-water mixture passing through the internal channel 11 of the drill bit nipple 2, and the targeted supply of the agent to the hydraulic monitor nozzles and into the bearing units of the drill bit cone, the internal channel 11 of the nipple 2 may consist of n channels where n≥1. At the same time, the flushing fluid or the air-water mixture cools the rock-cutting elements 10 and the bearing units of the cone of the drill bit.

Execution example

So, for example, a bit with a diameter of D = 711.2 mm has d = 144.550 mm. Thus, d / D = 0.203; a bit with a diameter of D = 241.3 mm has d = 131.030 mm. Thus, d / D = 0.543.

The above examples confirm the legitimacy of the claimed range d / D = 0.2-0.6.

Claims (4)

1. Drill bit containing a body with a conical nipple with an internal channel and a thread made on the nipple, flushing channels and grooves on the outer surface and rigidly fixed paws with cones fixed in the grooves of the body, characterized in that the outer diameter d of the thread of the small base of the cone of the drill nipple the bit is connected with the outer (nominal) diameter D of the drill bit by the ratio d / D = 0.2-0.6. 2. Drilling roller bit according to claim 1, characterized in that the outer diameter d of the thread of the pin small bases of the cone of the drill bit is associated with a diameter d _ext inscribed in the internal bore of the pin circle situated in the main plane of the thread of the pin of the drill bit, the ratio d / d _ext = 0.7-17.0. 3. A cone drill bit containing a body with a conical nipple with an internal channel and a thread made on the nipple, flushing channels and grooves on the outer surface and rigidly fixed paws with cones fixed in the grooves of the body, characterized in that n channels are made inside the nipple, where n≥, 2, and the outer diameter d of the thread of the small base of the cone of the drill bit nipple is connected with the outer (nominal) diameter D of the drill bit by the ratio d / D = 0.2-0.6. 4. The roller cone bit according to claim 3, characterized in that the outer diameter d of the thread of the small base of the cone of the drill bit nipple is connected with the diameter d _{n of the} circle inscribed in the inner channel of the nipple of the circle located in the main plane of the thread of the drill bit nipple, with the ratio d / d _v = 0.7-17.0, Where

where d ₁ , d ₂ , ..., d _n are the diameters of the circles inscribed in each of the internal channels of the nipple, located in the main plane of the thread of the drill bit nipple.

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