US2950090A - Mounting for discharge beans in well drilling bits - Google Patents

Description

K. H. SWART Aug, 23, 1960 MOUNTING FOR DISCHARGE BEANS IN WELL DRILLING BITS- 2 Sheets-Sheet 1 Filed Aug. 1, 1957 INVENTOR. kE/V/VETZ/ 5/4/497- Wil /1% 1960 K. H. SWART 2,950,090

INVENTOR. (EVA/E714 A. Ski 487 MOUNTING FOR DISCHARGE BEANS IN WELL DRILLING BITS Filed "Au 1, 19 57, Ser. No. 675,759-

6 Claims. or. 255-314 This invention relates to improvements in well drilling bits, and particularly to the manner in which flow beans are mounted in the discharge ends of the circulation passages in such bits.

Explanatory of the present invention, the usual well drilling bit has one or more circulation fluid passages formed therein through which circulation fluid that is forced down the drill pipe is discharged adjacent the cutters of the bit. In the discharge ends of these passages it is desirable to mount beans of hard abrasionresistant material, which beans, due to the constrictions thereof, cause the circulation fluid to be discharged in the form of relatively high velocity jets.

It has heretofore been proposed to install such beans in cavities in the body of the bit in alignment with their respective circulation passages and to retain them therein by means of snap rings. These snap rings are positioned against the lower ends of their respective beans and are allowed to expand into grooves in the body of the bit so that the snap rings, when in the grooves, project inwardly over the edges of the beans and lock the beans in position. This proposed construction has a number of disadvantages. An important disadvantage is that the snap rings themselves become highly abraded and sometimes are cut in two and when this occurs the bean can drop out of the bit body or be carried out of the bit body by the discharging circulation fluid.

Another objection resides in the fact that it is diflicult to ascertain from mere inspection as to whether the snap rings have been properly installed and have expanded into their respective grooves so as to be capable of locking the beans in position. It has happened that although the snap ring appears to be seated in its groove that actually the snap ring was not seated in the groove but was merely frictionally held against the wall of the bore in which the bean was positioned. This friction could of course be easily overcome when the circulation fluid is forced through the bean and the bean consequently can be expelled from the bit by the circulation fluid.

From a close study of the abrasive effects on the snap rings I have ascertained that in spite of the fact that the snap rings are at the lower ends of the beans and would theoretically be protected by the beans against the abrasion of the discharging circulation fluid, the abrasion of the snap rings nevertheless occurs and is probably due to the inward rushing of circulation fluid into the circulation passages and through the bit into the drill pipe occasioned by the lowering of the bit downwardly in the well.

An object of the present invention is to provide a simple, novel, and advantageous construction for mounting the bean in the body of a well drilling bit which will overcome these disadvantages in that the abrasion occasioned by the flow of circulation fluid either out of the ice bit in the course of drilling or into the bit in the course of lowering the bit into the well will not loosen the bean and allow it to become separated. Also, the construction will enable it to be instantly ascertained by mere inspection of the bit that the bean is properly installed in the bit and will not readily become lost.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a sectional view through a typical well drilling bit body illustrating a bit installed therein in accordance with the present invention;

Fig. 2 is a horizontal section taken substantially upon the line 2-2 upon Fig. l in the direction indicated; and

Fig. 3 is a partial view in vertical section illustrating details of construction and the manner in which the bean is mounted in the bit.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the body of the bit illustrated is of a typical tricone bit wherein the body is made up of three segments it), 11, and 12. These segments abut each other on three equally spaced abutting planes, one of which is indicated at 13. Steel dowels 14 are recessed in opposed segments and serve to hold the segments in mutual alignment with each other while they are being welded together as by welds 15.

In the abutting surfaces of the segments there are formed portions of circulation passages, one such passage being indicated at 16. These portions of circulation passages when the segments 10, 11, and 12 are assembled together, cooperate with each other to form three circulation passages designed to discharge circulation fluid that is pumped down the rotary drill pipe (not shown) and discharge it in a downward direction in the vicinity of the cutters.

In accordance with the present invention the lower ends of the circulation passages 16 are enlarged to receive a bean sleeve 17. Each bean sleeve, after having been positioned in the lower end of its circulation passage, is retained therein such as by a weld 18. The welding at 18 may be done at the same time that the welding at 15 is done, or it may be done at any time after the bean sleeve has been installed.

The bean sleeve adjacent its upper end has a tapering passage 19 formed therethrough that forms a short continuation of the circulation passage 16. It also has a downwardly facing shoulder 20 against which the top or inner end of a bean 21 is positioned. The bean 21 is formed of a hard abrasion-resisting material, such as for example tungsten carbide, or a hard abrasion-resisting ceramic. The interior of the bean adjacent its upper end forms a continuation of the passage 19 in the bean sleeve 17 but the lower or outer end of the bean is of reduced internal diameter as indicated at 22 so that the circulation fluid that is discharged through the bean will be discharged at high velocity and in the form of a jet stream. The exact size of the passage 22 in the bean 21 may vary and the size selected depends somewhat on the judgment of the operator on taking into consideration the nature of the formation that is being drilled through.

The bean 21 is retained in the bean sleeve 17 by means of a bean retainer 23 which is externally threaded with threads 24 that can be screwed into internal threads 25 in the lower end of the bean sleeve 17. As illustrated,

3 the bean retainer 23 has an internal shoulder 26 that is opposed to an external shoulder 27 on the bean. However, this construction is not essential and the bean can be retained in the bean retainer 23 in other suitable manners such as by soldering, brazing, or even by the use of a thermo-setting adhesive. If any of these latter means of attachment between the beanand the bean retainer 23 are employed the interior of the bean retainer and the exterior of the bean can be made perfectly'cylindrical and the shoulders 26 and 27 can be dispensed with. The top of the bean retainer 23 terminates short of the shoulder 20 in the bean sleeve 17 and in the space between the end of the bean retainer 23 and the shoulder 20 there is positioned a rubber O-ring 28. The space between the exterior of the bean 21 at the top thereof and the surrounding wall of the bean sleeve 17 is slightly less than the cross-sectional diameter of the rubber O-ring 28 so that when the bean 21, the retainer 23, and the O-ring are inserted into the bean sleeve 17 the O-ring will be slightly deformed or radially squashed. The bean retainer 23 is so proportioned that except for wrench slots 29 formed therein in its lower or outer end for the application of a spanner wrench or similar tool, that it is flush with the bottom of the bean sleeve 17.

It will be appreciated that with the bean 21 installed in the bit in the manner above described that circulation fluid forced downwardly through the bit will be discharged through the bean in the form of the desirable high speed jet. On the other hand, during the time that the bit is being lowered into the well and the circulation fluid is flowing in a reverse direction into the bit and into the drill pipe the abrasion of this reversely flowing circulation fluid is largely carried by the bean 21. Whatever abrasion occurs on the lower or outer end of the bean retainer 23 is not sufliciently great to cause the bean retainer to become destroyed and to allow the bean to become detached from the bit and lost. The compressed O-ring 28 performs a double function. It prevents leakage of fluid that occurs between the upper or inner end of the bean 21 and shoulder 20 from escaping between the threads 24 and 25 and cutting out these threads. It will also prevent leakage between the bean 21 and the interior of the retainer 23 in the event that the shoulders 26 and 2.7 are employed and there is no soldering, brazing, or adhesive between the bean and the retainer. The other function performed by the radially compressed ring is to function as a lock that will frictionally prevent the bean 21 and the retainer 23 from loosening or unscrewing from the bean sleeve 17. In order to gain this latter function the bean and the retainer should be rigid with each other such as by soldering, brazing, or the use of adhesive.

*It will thus be appreciated that the construction employed to mount the bean in the lower end of the circulation passage is such that the parts thereof are adequately protected against abrasion either in the course of drilling or in the course of lowering the bit into the hole, and that danger of loosening and losing the bean is eliminated;

Furthermore, the construction is advantageous in that by mere inspection of the bit it can be ascertained that the bean and its retainer are properly installed and will be retained. If the bean and its retainer 23 have not been screwed tightly against shoulder 20 then the bean and its retainer will project from the body of the bit a short distance. This projection immediately indicates to the observer that the bean and its retainer are loose and should be tightened up before the bit is run into the well.

It will be appreciated by those skilled in the art that the construction employed can be easily and economically manufactured, installed, and assembled with the bit. While the invention has been illustrated as having been incorporated in a bit body made up of three parts that have been mutually assembled together the invention is in no way restricted thereto and may be applied to any well drilling bit regardless of how the body may be constructed. The three-part body of a tricone bit have merely been illustrated and described as being a typical situation wherein the invention can be advantageously employed.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A Well drilling bit having in the discharge passage thereof for the discharge of circulation fluid a sleeve, a bean retainer threaded into the sleeve, a bean in the retainer, and a packing ring contiguously surrounding the bean and interposed between the bean and the sleeve beyond the end of the bean retainer, said bean and bean retainer having opposed mutually engaging shoulders for preventing axial movement of the bean relative to the bean retainer in an outward direction.

2. A well drilling bit having a body made up of two opposed parts which mutually engage and which are welded together, said parts cooperating to form a passage for the discharge of circulation fluid, a sleeve partially recessed in each of said parts in alignment with said passage and welded in position, said sleeve being internally threaded, an externally threaded bean retainer screwed into the sleeve and a bean secured in the bean retainer, said sleeve having an internal outwardly facing shoulder against which the bean bears, and a rubber O-ring contiguously surrounding the bean and interposed between the bean and the sleeve and between the bean retainer and said shoulder.

3. A well drilling bit having a body made up of two opposed parts which mutually engage and which are welded together, said parts cooperating to form a passage for the discharge of circulation fluid, a sleeve partially recessed in each of said parts in alignment with said passage and Welded in position, said sleeve being internally threaded, an externally threaded bean retainer screwed into the sleeve and a bean secured in the bean retainer, said sleeve having an internal outwardly facing shoulder against which the bean bears, and a rubber O-ring contiguously surrounding the bean and interposed between the bean and the sleeve and between the bean retainer and said shoulder, said rubber O-ring being normally of greater thickness than the thickness of the bean retainer and being radially compressed and serving to prevent leakage between the threads and between the bean and bean retainer.

4. A well drilling bit having a nozzle or bean for the discharge of circulation fluid, said bit having a shoulder facing toward the discharge end of the bean, a bean retainer surrounding the bean and threadedly mounted upon the bit so as to be tightenable toward the shoulder, and a packing disposed between said shoulder-and said bean retainer and arranged contiguous to the portion of the bean adjacent the shoulder, the bean being retained against axial displacement outwardly relative to the bean retainer.

5. A well drilling bit having a passage therein for the discharge of circulation fluid, said passage presenting an outwardly facing shoulder adjacent its lower end, a nozzle or bean abutting said shoulder, a bean retainer surrounding the bean and in which the bean is held against outward displacement, said bean retainer being threadedly mounted on the bit, and a rubber 0 -ring contiguously surrounding the inner end of the bean between the inner end of the bean retainer and said shoulder.

6. A well drilling bit having a passage therein for the discharge of circulation fluid, said passage presenting an outwardly facing shoulder adjacent its lower end, a nozsurrounding the inner end of the bean between the inner end of the bean retainer and said shoulder, said O-ring References Cited in the file of this patent UNITED STATES PATENTS 1,143,273 Hughes June 15, 1915 1,174,575 Hughes Mar. 7, 1916 1,911,659 Weaver May 30, 1933 6 Flynn May 8, 1934 Pennington Apr. 7, 1942 Stokes Oct. 8, 1946 Goolsbee et a1. Oct. 10, 1950 Yancey et a1 Aug. 28, 1956 FOREIGN PATENTS Great Britain Mar. 2, 1955 France Nov. 28, 1955

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