US 2108955 A
Description (OCR text may contain errors)
0 R Y ww Z mh E l l l N j I|H\ 1 I ,Jnvi N/ R 2 d w d il" f, N r. 1M A H M W 7 Feb. 22, 193.8. J. A. zUBLlN FLUID PASSAGE FOR DRILLING TOOLS Filed June 2, 1936 Patented Feb. 22, 1938 UNITED STATES PATENT OFFICE 4 claims.
v'Ihe present invention relates generally to tools for drilling wells, and is particularly concerned with means for conducting' and directing to the bottom of the hole the circulation fluid used to 5` clean the cutting elements and carry cuttings to the surface.
In drilling tools of various types, the circulation fluid is often discharged from the tool at a point considerably above the bottom of the hole. As a result, the cutting elements are sometimes not cleaned as effectively as they should be, and the stream of uid does not clear away all the cuttings, but instead leaves a layer of them over the bottom. To operate with best eiliciency, the stream of fluid should be led as near to the bottom of the hole as possible and in such a way that it washes the sides of the bore and ushes all cuttings ol the bottom. As the uid passes the cutting elements, they will be washed Clean. y n
'I'hus it is a general object of my invention to improve iluid circulation by providing a drilling tool with fluid passages that conduct the circulation fluid to a point very near the bottom of the well to wash away all cuttings and clean the cutting elements of the tool.
It is also an object to provide a drilling tool with fluid passages such that the fluid washes the sides of the hole as well as the bottom.
To achieve these objects in a drilling tool having an internal -passage for circulation uld, I provide an external channel which receives fluid from the internal passage and which extends down an outer face of the tool to a point near the bottom of the tool. The channel is open on one side, and is so positioned on the tool that it is very close to the vertical wall of the well. The well wall acts as a closure for the open side of the channel and uid is, with the cooperation of the well wall, at least partially confined in the channel.
How these and other objects and advantages of the invention are attained will best be understood from reference to the following description and the annexed drawing, in which:
Fig. 1 is a side elevation of a drill bit with cone cutters, the body of the bit being broken away to show the external water channel;
Fig. 2 is an elevation of another type oi.' bit with movable cutters showing the external water channel in elevation;
Fig. 3 is a fragmentary elevation partially broken away to show external water channels in a core head having iixed cutting blades;
Fig. 4 is a horizontal section on line 4-4 of Fig. 3; and
Fig. 5 is an elevation of a 4-way drag bit with external water channels.
There is shown in Fig. 1 a conventional type 5 of drilling bit having a body or shank I0 provided at its upper end with a threaded pin II by means of whichthe bit is attached to a string of drill `pipe for rotation. The cutting elements are the cone cutters I2 rotatably mounted in any suitable l0 manner upon the lower portion of body I0. Body Ill is provided with an internal passage I5 which receives from the drill pipe the circulation fluid used to keep the cutting elements clean and carry cuttings to the surface.
The tool is provided with one or more external uid channels I8 which communicate at their upper ends with internal passage I5, each channel receiving circulation iiuid through a nozzle I9. Each channel I8 is preferably generally U-shaped 20 in cross-section, although it will be realized that the exact shape and relative dimensions may be varied considerably, and lso `is open to the .tool exterior along one side as well as at its lower end. The channel I8 is so positioned on the tool that 25 it is in close proximity to the vertical wall 20 of the well; that is, it is placed so that the portions of the tool at the sides of the channel have but a small clearance between them and the sides of the well. In this way,wal1 20 acts as a closure 30 member that at least partially, though usually not completely, closes the open side of the U- shaped channel I8 to confine the stream of fluid therein. Of course, the clearance between the tool and Wall 2U will permit a certain proportion 35 of the circulation fluid to move outwardly, but the clearance is small and the partial closure of the channel is suiiicient to maintain in each channel a definite downward flow of fluid confined therein and issuing for the most part at the 40 bottom of the channel.
With this construction, the stream of circulation uid issuing from nozzle I9 -strikes wall 20' and i's deected downwardly in a stream that, 45 with the cooperation of the well wall, is confined and conducted downwardly by channel I8 to a point near the bottom of the tool where it is discharged at the bottom of the well. It will be understood that the stream of uid washes down 50 the sides of the wall before it reaches the bottom of the well where it flushes the cutters and carries away debris.' and that as the bit rotates in the well, each channel I8 passes in front of the entire circumference oi wall 20 so all portions bit with rolling cutters.
of wall 20 at soine time act to confine the uid stream.
Fig. 2 shows the application of the invention to another type of drilling tool fully described and claimed in my copending application Ser. No. 71,600, filed March 30, 1936, on Rotary drill The bit has a body 25 upon which are rotatably mounted a pair of carriers 26, each provided about its periphery with a number ofcutters 21. As before, channel |8a is placed in the body of the tool where it will be in close proximity to the walls of the well. The channel receives circulation uid at its upper end from the internal fluid passage I through nozzle 29.
Where the tool has flxed cutting elements as, for example, blades, the external channel may be placed in these blades instead of the body of the tool as described above, in order to bring it into proper position to'cooperate with the well wall. A construction of this type is shown in Figs. 3 and 4, wherein isillustrated the lower end of a core bit comprising a head 30 attached to the lower end of the outer barrel 3l, and an inner barrel 32 for receiving the core. Core head 30 is here illustrated as having four cutting blades 34, although a larger or smaller number may be used. Circulation uid flows downwardly through the annular space 36 between the inner and outer barrels and thence through passages 31 to the upper ends of external channels |817 which are placed one each in the outer faces of blades 34.
Since the vertical edges of blades 34 are used for reaming, the forward edges of these blades will contact wall 20 of the hole being drilled, while the rear edge will clear'the wall slightly, as shown in Fig. 4; though after the bit has been worn, both the forward and rear edges of the blade may touch the hole sides, thus completely closing the open side of channel lsb. In the same manner as described before, a stream of circulation uidwill enter the upper end of each external channel I8b from passage 31 and move downwardly therein. Since it is confined within the channel by wall 20, which covers the open vertical side of the channel, the stream then issues from the channel at a point near the bottom of the tool. The fluid moving downwardly through the channel washes the walls 20 and, as the bit rotates, comes in contact with all portions of the wall.
Fig. 5 illustrates a four-blade drag bit having external water channels I8c down the outer edges of the blades 40, in the same manner as those described in connection with Fig. 3. The extern'al channels have a section along the upper inclined portion of the blade where the wall 20 is not sufficiently close to confine the stream. However, the stream of fluid, after issuing from body 4i, is carried along the upper inclined section of channel I8c by reason of its own momentum until it strikes wall 20, by which it is deflected downwardly through the lower portionof channel around the tool provides the path'cr channel taken by the outgoing fluid as. it rises past the tool on its way to the groundl surface, and that the channel for downcoming fluid is separated by parts of the tool and therefore distinct from the path taken by upwardly moving uid.
Although I have shown the. application of my i invention to some typical drilling tools it will be understood that the invention may be applied to many other tools, and may be changed without departing from the spirit and scope of my invention; and it is to be understood that the foregoing description is to be considered as illustrative of rather than restrictive upon the scope of the invention described in the appended claims.
I claim as my invention:
1. A well drilling tool with cutting elements and an internal passage for circulation fluid, having an external iluid channel communicating at its upper end with the internal passage to receive fluid therefrom, said external channel being open to the tool exterior on one vertical side and at the lower end and so positioned on the tool in close proximity to the vertical well wall throughout substantially its entire length that the well wall at least partially closes the open vertical side of the channel to conne downwardly moving fluid therein, and a second external channel in which the fluid moves upwardly past the tool.
2. A well drilling tool with movable cutting elements mounted on a body and an internal passage for circulation fluid, having an external fluid channel in said body communicating with the internal passage to receive uid therefrom, said external channel being open to the tool exterior on one side and so positioned on the tool body in close proximity to the well wall throughout substantially its entire length that the well wall at least partially closes the open side of the channel to confine fluid therein, and a second external channel in which the fluid moves upwardly past the tool.
3. A well drilling tool with a fixed cutting blade mounted on a body and an internal passage for circulation fluid, having an external fluid channel in said cutting blade communicating with the internal passage to receive fluid therefrom, said external channel being open to the tool exterior on one side and so positioned on the blade in close proximity to the well wall that the well wall at least partially closes the open side of the channel to conne fluid therein. 4. An earth boring tool comprising cutting elements, an internal passage for circulating uid in said tool, a channel on at least one of said cutting elements having communication with said passage, said channel being open on one side at the tool vexterior and being so positioned that when the tool is in a bore the walls of the bore Willl be in close proximity to the channel throughout substantially its entire length to close eifectively the open side of the channel and guide fluid therein.
JOI-IN A. ZUBLlN.