US2293259A - Device for preventing clogging of drilling bits - Google Patents

Description

Aug-18,1942. @.'JQ'HNSQN 7 2,293,259' l DEVICE-Fon- PREVEMIN CLOGGUG oF DRILLING BITS y Filed ual-ches, 1941 4 2 sheets-Shen 1 ai Y a mj: 20 V20 a 'A' ATTORNEY.

I Aug. 1s, 1942. 5.` n. JOHNSQN' DEVICE .FOR PREVETING CLOGGING OF DRILLING BITS Filed arch 29, 1941 '2 sheets-sheet 2 ATTORNEY.

Patented Aug. 18, 19.42 i

DEVICE Fon `irtuviirrrnaa oLoGGmG oF Damme ni'rs .Clyde D. Johnson, Parkersburg, W. Va., assignor tov Acme Fishing` Tool Company, Parkersburg.

Va., a corporation of West Virginia Application March 25, 1941, serial No. ,$135,110

. i 1 Claim.l (Cl. 255-61) The present invention relates to an apparatus` for use with rotaryl well drilling tools.

In that art, a cleansing fluid is pumped axially through the drill stem or drill pipe and the rotary drill bit so as to remove detritus loosened by the bit, from the hole. It frequently happens in drilling that the teeth of the cutters on the bit proper become 'clogged with mud or the like' so as to decrease the bits cutting efficiency.

The principal object of the invention, therefore, is the provision of an attachment whereby multiple streams of cleansing fluid maybe diverted from that passing downwardly through the drill pipe to the bit, the diverted streams passing downwardly and outwardly through the attachment, some of the diverted streams impinging upon the teeth of the cutters so as to prevent an accumulation of mud, rock or dirt at that point and others of the diverted streams impinging directly upon the bottom of the hole being drilled, immediately washing away and upwardly all loose cuttings. This prevents the bit from grinding the cuttings over and over with resultant clogging of the bit and greatly increased torque on the drill pipe, that sometimes causes twist-off.

The invention further contemplates a provision for preventing a ow of liquid with its contained detritus from arising through the axial bore in the bit when the uid pumping operation is ceased, for instance during a drill withdrawal period, or when lowering the drill pipe in the hole after it has been withdrawn to put on a fresh bit or for other purposes.

The invention further contemplates the provii sion of a series of huid conducting passageways in the drill attachment so that regardless of the stopping position of the bit when it is screwed into the bottom of the attachment, there will be one or more passageways arranged with relation to the bit teeth so that the latter will be washedl by fluid ejected through the former, and others will direct streams of uid at high velocity' to impinge upon the bottom of the hole being drilled to wash away cuttings as they are loosened by the bit.

The invention further includes the novel combination, arrangement and construction of parts more fully hereinafter described and shownin thedrawings, in which- Fig. 1 is a side view partly in section o f a combination involving the present invention;

Fig. 2 is a sectional view through a part of the drill string showing one'embodiment of the invention;

Fig-3 is a sectional planview along the line 3-3 0f F18. 2;`k

Fig. 4 is a sectional view Aalong line 4--4 of Fig. 2;

Fig. 5 is a plan view of the housing of the attachment with the interior parts removed;

Fig.- 6 is a perspective view of the strainer mechanism; i

Fig. '1 is a perspective view of the valve; and

Fig. 8 is a sectional elevation showing one form of fluid conducting tube and cap.

Referring now with particularity to the ernbodiment illustrated, a drill collar is shown at I to which a double pin sub 2 is attached in the usual manner. A body or housing 3 is attached to the sub 2 by the usual threads, the drill bit-4 being carried in the threaded bottom portion of the body 3.

The housing or body 3 is provided with an axial bore in which is located a strainer element 5 having a restricted lower portion Ii, an enlarged upper portion 1 and an intermediate perforated portion 8.

A coil spring 9 located in a. recess which sur-i rounds restricted portion 6 of the strainer tends to push the entire strainer upwardly so that the top of the enlarged portion 1 engages against the bottom of the sub 2.

The enlarged portion 1 of the strainer is provided with a web III4 axially perforated to receive the valve stem I I.

The valve assembly includes a base plate I3,

v the rubber valve proper Il and a cap nut I5, all

held on the stem II.' A coil lspring I6 encircles the valve stem and tends to push the rubber valve part I4 against the seat I1 surrounding the bore in the bottom of the sub.

The-lower portion of the housing 3 is provided with recesses to receive a series of `fluid conducting tubes I8 tapered as at I! so as to limit their position within the housing. The lower end 2li of the uid conducting tubes I8 are soarranged with relation to the cutters on the drill bit 4 that fluid ejected therethrough impinges upon the cutter teeth and/or upon the bottom of the hole as shown in Fig. 1 at 22. y

In operation, when fluid is pumped through the bore of the drill string, it depresses the spiral spring I8, opens the valve and passes into the top of the strainer. From there it passes on each side of the web III completely through the strainer in an axial direction, and through the bore of the drill bit and performs its function in washing the detritus from the hole, returning to thesurface where it is recycled.

During this passage, a part of the iluid ls diverted through the perforations in the strainer and passes downwardly and outwardly through the iluid conducting tubes I8 to keep the cutter teeth clean and the cuttings washed from the bottom of the hole, as above mentioned.

It is to be noted that when for any reason the drill string is to he removed from a hole, the pumping of the washing fluid is stopped. Assoon as this happens, the spring I8 closes the valve I4 tightly against the seat on the sub, thus ei'- fectively preventing the rise of iluid up through the center of the drill and housing. Consequently, there will be no accumulation of deposit in these parts in the interim of the non-pumping period. As soon as the pump is again started, the valve Il opens and the cycle is repeated. When the drill string is withdrawn from the hole, the weight of the fluid in the drill pipe depresses the spring I 8, opening valve Il and permitting the iluid to drain out oi' the pipe as it is withdrawn. When the bit and drill pipe are run back in the hole, valve Il being closed, prevents a rise of iiuid through the drill and housing, thus avoiding accumulation of deposit in these parts and also helping to support some of the weight of the,

drill pipe. 'I'his relieves the strain on the cables and equipment.

There are occasions when it is not desirable to have all of the iluid conducting tubes in the series open, as shown particularly in Fig. 1 and Fig. 4. For instance, when it is desired to increase the pressure and velocity of the fluid, one or more of the iluid conducting tubes can ibe capped oil' by means of cap 2| as shown in Fig. 8. Thus any number of the tubes may be used as desired.

From the above, it will beapparent that a de- Vice has lbeen lprovided which may be readily attached to a drill string Ibetween the bit and either the drill collar or a sub, which will not only prevent .back pressure, causing a rise o! il-uid through the drill, but will also permit dlverting washing fluid against the teeth o1' the cutters so as to prevent their clogging with consequent loss of elciency, and also divert washing fluid to the bottom of the hole at high velocity to remove cuttings as they are loosened by the bit.

The parts so provided are simple in construction, and readily assembled so that any one of them may |be replaced quickly while the drill string is out of the hole. f

While the invention has been shown and described with particular reference to specic embodiments, it is to be understood that it is not to be limited thereto but is to be construed broadly and restricted solely by the scope of the appended claim.

I claim:

In combination, a drill pipe, a rotary drill bit, a housing attached to the lower end of the drill Ipipe, said housing having fluid-conducting passageways therein to conduct a stream of washing fluid therethrough and to discharge the same onto the outer face of the drill bit, 'said housing having an axial bore through which washing iluid ilows on the Way to the drill bit and the duid-conducting passageways, means to close said bore against back iluid pressure, a strainer element telescopically received within the axial bore in the housing, a spring pressing the strainer element upwardly against the drill pipe, said iluidconducting passageways in the housing receiving iluid from the exit side of the strainer and means to close oi one of the passageways not in line with the drill -bit after the bit has been put inplace.

CLYDE D. JOHNSON.

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