US2950089A - Rotary drilling bits - Google Patents

Description

Aug. 23, 1960 R. D. IRONS ROTARY DRILLING BITS Filed Sept. 11, 1957 R. D I ro n s INVENTOR I BY W ATTORNEY United States Patent Q ROTARY DRILLING BITS R. D. Irons, Ozona, Tex., assignor of one-half to Ole K. Olsen, Garland, Tex.

Filed Sept. 11, 1957, Ser. No. 683,277

2 Claims. (Cl. 255-61) This invention relates to rotary drilling bits and more particularly to drilling bits having means for circulating fluid to the bottom of the well being drilled thereby.

One object of the invention is to provide a new and improved rotary drilling bit.

Another object is to provide a drilling bit having means for circulating fluid to the bottom of the well being drilled thereby whereby the cutting blades of the drilling bit may be lubricated and cooled by the fluid and the cuttings carried upwardly thereby to preclude clogging or sticking of the drilling bit by such cuttings.

Still another object is to provide a drilling bit, of the type described, wherein the means of the drilling bit for circulating fluids produces a plurality of jets of fluid which carry cuttings from the bottom of drilled well.

A further object is to provide a drilling bit, of the type described, wherein the jets of fluid are so directed as to minimize turbulence in the fluid at the bottom of the well and thus prevent undue enlargement of the diameter of the well which would tend to permit caving of the earth formations into the well.

A still further object of the invention is to provide a drilling bit, of the type described, wherein the means for circulating fluid produces upwardly directed jets of fluid for carrying cuttings from the bottom of the well.

Another object is to provide a drilling bit, of the type described, wherein the means for circulating the fluid also provides circulation of fluid about the cutting blades to lubricate and cool the cutting blades.

Still another object is to provide a drilling bit, of the type described, wherein the upwardly directed jets of fluid have a greater volume of flow than the fluid circulated about the cutting blades.

A further object is to provide a drilling bit having a hollow body provided at its exterior with radially extending cutting blades and with flow passages communicating with the interior of the body and opening between the cutting blades, and wherein the hollow body is provided with deflecting means which are positioned exteriorly of the body between the cutting blades and extend over the flow passages and deflect upwardly along the exterior of the bit body a major portion of the fluid issuing from the flow passages so that the upwardly directed fluids are directed upwardly in the annular space between the drill bit and the wall of the bore of the well.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and references to the accompanying drawings thereof, wherein:

Figure l is a side clevational view of a rotary drilling bit embodying the invention;

Figure 2 is a view, partly in elevation and partly in section, of the drilling bit shown in Figure 1;

Figure 3 is a top view of the drilling bit; and

Figure 4 is a bottom view of the drilling bit.

Referring now to the drawings, the rotary drilling bit includes a hollow body 11 having a lower closed portion 12 and a conventional upper tapered threaded portion or pin 13 by means of which the drilling bit may be secured to the lower end of a drilling string down which a fluid, such as air or liquid may be pumped or forced into the body The lower closed portion 12 of the hollow body is provided with a plurality of spaced radially outwardly extending cutting blades or members 14 each having stepped cutting edges 15, 16 and 17. The lowermost cutting edge 15 of each blade may have a portion 15b which slopes outwardly and upwardly and a portion which slopes inwardly and upwardly from substantially the mid-portion of such edge.

The lower closed portion 12 of the hollow bit body 11 is provided with a plurality of flow passages 20, each of which is disposed between a pair of adjacent cutting blades or members 14. The flow passages 20 provide communication between the interior of the hollow bit body and the exterior thereof to permit fluid circulated through the drill string into the bit body to flow outwardly therefrom to cool and lubricate the cutting blades or members 14 and also scavenge or carry off the cuttings produced in drilling.

The flow passages 20 extend downwardly and outwardly and have their outer ends disposed slightly above the highest cutting edge 17 so that fluid flowing or ejected through these passages tends to form jets which are directed downwardly and outwardly toward the bottom of the well bore adjacent the cutting faces of the cutting edges of the blades. If such flow of fluid is unrestrained or undirected, these jets of fluid set up a turbulence at the bottom of the well which, particularly in looser or readily fragmenting formations, tends to enlarge the diameter of the hole and cause undesirable cave-ins of the side wall or bore wall of the well, and also tends to keep cuttings and debris at the bottom of the well where they interfere with the cutting action of the drilling bit.

In order to prevent such undesirable flow of the fluid, the bit body. is provided with deflectors or flow directors 22. Each of the deflectors has a web portion 23 whose lower end portion inclines downwardly and inwardly to the bit body and whose lower edge 24 extends across one of the flow passages 20 of the bit body in such manner that a major portion of the flow passage extends above the edge 24 whereby a major portion of the fluid flowing from the flow passages 20 is deflected upwardly by the web 23 and only a small portion thereof flows downwardly of the deflector. Each deflector is also formed with widely extended side flanges 25 which connect the web portion 23 to the bit body. The upper ends of the deflectors 22 terminate or are disposed in substantially the same plane as the upper ends of the cutting blades or members14 and the lower ends thereof are above the cutting edges 17 while the side flanges 25 thereof are of lesser width than the cutting blade so that the deflectors are disposed inwardly of the outer edges of the cutting blades or members and thus do not interfere with the cutting action of the cutting blades.

The edges 24 of the web members 23 may be cut away slightly into a concave shape adjacent the flow passages 20 to permit a greater volume of fluid to flow downwardly of the deflectors and between the cutting blades.

It will be seen that the upper ends of the web portions 23 of the deflectors are spaced from and substantially parallel to the adjacent substantially vertical outer surface of the lower closed portion 12 of the drilling bit body whereby the fluid from the flow passages. 20 is deflected upwardly in jets which flow upwardly substantially parallel to the drill string.

In use, the drilling bit is secured to the lower end of a drill string by means of the threaded upper portion 13 of the body 11. As the drill string is rotated, fluid such as air, water or other suitable liquid, is forced or pumped through the drill string into the interior of the bit body 11 and thence through the flow passages to the exterior thereof. As the drilling bit is rotated, the stepped cutting edges 15, 16 and 17 of the cutting blades 14 engagej the earth formation through which the well is being drilled and cut thereinto producing cuttings which must be removed. The smaller portion of the fluid which flows. or jets downwardly from the flow passages moves downwardly of the deflectors. and then upwardly between the cutting blades 14. During this movement, this portion of the fluid lubricates and cools the cutting blades and also moves or transports cuttings upwardly between the cutting blades 14.

A major portion of the fluid from the flow passages? 20 is directed or deflected upwardly by the deflectors and carries the cuttings directly upwardly. The upward strong jet of fluid so deflectedhas a larger volume of flow than the jet which flows downwardly of the deflectors. 7

Thus, a major portion of the fluid circulated is neverv directed outwardly against the sides of the well, which would tend to cause enlargement of the well, but is directed upwardly to carry cuttings upwardly in the well to the surface.

The deflectors and cutting blades are preferably welded to the bit body for greater strength. While a particular form and shape of cutting members have been shown and described, it will be readily apparent that other types and styles may be as well employed.

It will now be seen that the new and improved rotary drilling includes a hollow body 11 closed at its lower end and having means 13 at its upper end for securing the bit to the lower end of a drilling string. It will also be seen that a plurality of radially disposed cutting means or members 14 aresecured to the body which is provided with flow passages between the cutting means where by fluid may be circulated from within the body to the cutting means to cool and lubricate such cutting means. It will also be seen that deflectors 22 are provided on the hollow body 11 to direct a major portion of the-fluid escaping from the flow passages 20 to produce upwardly directed jets of fluid to carry cuttings from the well bottom while restricting the amount of fluid flowing from the passages 20 to the cutting members.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made bythose-skilled in the art, with: in the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desiredto be secured by. Letters Patent is:

1. A rotary drilling bit including: a hollow body. having a closer lower end and means on the upper end for securing the body to the lower end of a drill string; a plurality of outwardly and downwardly extending cutting members on the exterior of and projecting laterally beyond the periphery of said body, said body having a plurality of flow passages, one of said passages opening downwardly and outwardly between each two adjacent cutting members; and deflecting means disposed exteriorly of said hollow body between each two adjacent cutting means for deflecting upwardly a major portion of fluid passing outwardly from the flow passage opening outwardly between the two adjacent cutting members between Which the deflecting means is disposed, each of said deflecting means beingdisposed inwardly of an arc defined by the outer edges of the cutting means as the bit is rotated and comprising a web portion having a lower edge secured to the body and extending across the outer end of the opening of a flow passage, said web portion extending upwardly from its lower end spaced outwardly from the exterior of the body to provide an upwardly directed flow course between said web portion and said body, the edge of the web portion extending across the opening of the flow passage dividing the fluids flowing outwardly of said flow passage'whereby a portion of, the fluid passing outwardly from the flow passageflows downwardly below the deflecting means and another. portion is deflected upwardly.

2. A rotary drilling bit including: a hollow body havinga closed lower end and means on the upper end for securing the body to the lower end of a drill string; a plurality of outwardly and downwardly extending cutting means on said body, said body having a plurality of flow passages, one of said passages opening outwardly.

and downwardly between each two adjacent cutting means; and a deflecting means disposed exteriorly of the body between each two adjacent cutting means for deflecting upwardly a major portion of the fluid passing outwardly from the adjacent flow passage, each of said deflecting means comprising a web portion disposed on the exterior of said body and having a lower edge secured to the body and extending across the outer lower end of the adjacent flow passage opening outwardly between the two adjacent cutting means, said such portion extending upwardly between the two adjacent cutting means and spaced outwardly from the exterior of the body toprovide an upwardly directed flow passage between said web portion and said body, the lower edge of the web portion dividing the downwardly directed flowing fluids exiting from said flow passage into two portions, whereby a portion of the fluid passing outwardly from the flow passage flows downwardly below the deflector and another larger portion is deflected upwardly, said deflecting means having an upper end disposed substantially in the same plane as the upper ends of the cutting means, whereby said major portion of said' fluid is directed upwardly around the exterior of said drillbody above said blades.

References Cited in the file of this patent UNITED STATES PATENTS- l,587,194 Sladden June 1, 1926. 1,615,596 Phipps Jan. 25, 1927

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