US2181284A

US2181284A - Spudding bit

Info

Publication number: US2181284A
Application number: US98695A
Authority: US
Inventors: Ernest L Potts
Original assignee: Eastman Oil Well Survey Co
Current assignee: Eastman Oil Well Survey Co
Priority date: 1936-08-31
Filing date: 1936-08-31
Publication date: 1939-11-28
Anticipated expiration: 1956-11-28

Description

E.L.POTTS SPUDDING BIT Nov.28,l939.

Filed Aug. 31, 193 6 Patented Nov. 28 1,939

um'reos'rAra-s j -PATENT" orrlce man Oil We,ll Survey corporation.

Company, Dallas, Tex, a

Application n w: :31, 1936, Serial No. 93,695 a 3 Claims; (01. 255-)- tended direction thereof. 'Such a deflection is tion so that when pressure is detrimental because it increases the 'dimculty and the cost of drilling and interferes with the positioning of the casing, tubing and pumping equipment in the well.

sible.

where the deflection of the well'bore occurred.

A suitable milling tool or drill] is then used on the whipstock or concrete plugso that in this crete is deposited about the obstruction and the l 1 we 1 bore deflected from the concrete or i j in this manner, can arise. In some instances the stock may be set. V Diiiiculty has been encountered in both of the above instances in properly deflecting ther'well bore immediately adjacent the whipstockor'the concrete which has been positionedin ,th'ewellbore. Some of this difliculty has been-dueto the fact that a rotating bit is used to efiect the. deflecting action and ,it is impossible to deter mine in what direction the deflection is initiated I so that one of the objects of the presentinvention is to provide a spudding bit which willnot be rotated but which will be reciprocated in order to effect the deflection of the bore closely adjacent the whipstock or concrete.

It is one of the objects of the present invention to provide a spudding bit by which the di rection of the well bore may be changed.

Another object of the invention is to provide a spudding bit which is of chisel-likeconstrucwill move off at an angle.

Another object of the invention is to provide a chisel bit for spudding operations wherein the It is,-therefore, desirable I to normally maintain the direction of the well bore as nearly to the intended 'directionas pos-.

In event the well bore is'deflected.--, for some reason or other, it is the usual practice to eitherfill in or plug back the well bore with iconcrete or to set a whipstoclr at the elevation applied to" it it cutting edge is ofi center and a passage for fluid is provided through the bit.

Still another object of the invention is to provide-achisel bit whose angular position is capable of adjustment. e

Other and further objects of the invention will be readily apparent when the following descript'ion'is considered in connection withthe accompanying drawing, wherein Fig. 1 is a side elevation of the spudding bit with certain portions broken away'to illustrate the construction thereof.

Fig. 2 isaview of the front face of the bit showing the construction of the water course and the connection of body and the blade.

' Fig.3'is a section taken on the line 3-3 of Fig.- 2 and showing the arrangement for the water passage.

Fig. 4 is a diagrammatic view showing'the useof the bit where a straight hole is to be deflected.

. .Fig. 5 is a diagrammatic view of a crooked well which is to be'stlaightened.

In the drilling of wells particularly by the rotary method a drill bit is advanced into the ground by rotation, of a drill stem and the circu- .lation of drilling fluid through the drill stem and drill bit. A well bore which has been formed in this manner is illustrated generally at 2 in Fig.

- 4, and is shown as having been plugged at its lower end by a body of cementitious material such as 3.' Various causes for plugging a well bore may have been drilled into an undesirable formation. such as salt or salt water, and it has been desired to plug oil. the undesirable formation and. to continue the drilling of the well at an angle so that it may be possible to avoid the gradually deviates from the original well bore. a

The difliculty with bits ofthis' nature which retate resides in the fact that the operator is unable to control the direction at which the deviation is to occur. That is, looking at the well bore in plan view the deviation may occur in any direction of the compass, which of itself may-be undesirable, because in some instances by deflecting the well in a particular direction it may be possible to penetrate some known or desirable formation.

the faces of the shanks.

The present construction has been developed with a view of initiating the deflection of the well bore in the desired direction and, as seen in Fig. 4, the spudding or chisel bit 5 is shown as being applied to the top 4 of the cement plug 3 so that the cutting edge 6 thereof will be deflected along the line of the arrow I, or in other words it can .be directed in a controlled manner from the top of the cement plug 3. The spudding bit 5 is operated by the string of pipe 8 and has a swivel or pivot joint 9 therein by which the angular position of the blade 5 with respect to the operating string 3 may be set at any desired angle.

In Fig. 5 the construction of thestem, bit and plug are the same as described in connection with Fig. 3, except in Fig. 5 the well bore 2 is deviated from the vertical at the point l and the cement plug 3 has been so positioned that when the bit is deflected therefrom it will tend to direct the well bore more nearly toward the vertical than it was before the cement plug 3 was positioned. In other words, the bit may be used to deflect a hole from the vertical or to bring the hole back to the vertical, depending upon the circumstances of any particular case.

The particular construction of the bit is best seen in Figs. 1, 2 and 3 wherein the operating stem 8 is shown as threadedly connected to the bit body I5. This body is of peculiar formation and has its lower end formed with the separated shank portions l1 and I8. These shank portions are spread apart to provide a recess 20, which is to receive the shank 2| of the bit blade 22. This construction is best seen in Figs. 2' and 3. A pivot pin or shaft 24 projects through suitable openings in the shanks l1 and I8 and 2|, so that the blade is capable of a swinging movement relative to the body l5. In order to control this swinging movement a set screw 24 is provided on the heel 25 of the blade 22 and is arranged to abut against the shoulder 25 on the body I5.

It seems obvious that by adjustment of this setscrew 24 the angular position of the blade 22 can be set with respect to the body l5. A similar set screw 28 may be provided on the front portion of the body l5 so that pressure can be brought against the shoulder 29 on the bit blade. By adjusting both of these set screws and turning them down tightly the exact angular position of the blade with respect to the body may be determined and fixed for any desired angle of deviation.

In order that flushing fluid may be circulated through the bit the body I5 is provided with a passage 30 which extends downwardly into the shanks IT and I8 and then extends laterally therethrough into the chamber 3|, which is formed in each of the shanks. This chamber opens against the shank 2| of the blade 22 and if desired a ring packing 33 may be provided in each of these chambers so as to form a seal between This packing may be of any desired type or configuration so long as a seal under pressure will be formed. The pivot pin 24 is shown as having been welded in position in the shanks "and I8 by the band of welding material 35, but it may be positioned in any other manner desired.

The shank 2| of the bit blade 22 is formed with a recess 36 which communicates with the chambers 3| and in turn with the passage 3'1 which extends downwardly through the bit blade and terminates in the discharge port 38 in the lower end thereof. In this manner a continuous passage is formed from the operating string 3 to the cutting edge 3 of the spudding bit.

The blade 22 is of a particular construction which is seen in detail in Fig. l as embodying the front face 40 and the back face 4|.. 'These faces are opposed to each other in order to form the body and while they are substantially flat in transverse elevation the face 40 is curved but very slightly along the longitudinal axis of the blade, so that the cutting edge 6 of the blade is closely adjacent the outer edge 42 of the front of the blade portion, whereas the back face 4| is curved materially as seen in Fig. 1, until it meets with the face 40 at the cutting edge. In this manner the blade assumes the form of a chisel with the cutting edge 6 off center or offset with respect to the center line of the bit. The object of this offset position of the blade is readily apparent from the showing in Figs. '4 and 5, because it is desirable to spud the bit against the cement plug 3 or against the well bore formation in order' to start an opening in the desired deflected direction.

It will be understood that this bit is not rotated but is what is known as a spudding bit, which is manipulated by raising it and dropping it sharply against the formation. The weight of the operating stem 8 added to the weight of the bit strikes a substantial blow which drives the cutting edge 6 into the formation. In practice, if it is intended to control the direction of the deflection, then the bit is attached to the operating string and oriented into the hole so that the operator knows the direction at which the cutting edge 6 will penetrate the cement plug and the well bore. There is no rotation while this bit isbeing lowered 'into the hole and in this manner the well can be deflected in any direction of the compass desired and the steepness of the angle of deflection can be determined by adjusting the

set screws

24 and 28, if a steeper angle of deflection is desired than the difference between the opposed faces and 4|.

In some instances it may not be desired to deflect the hole in any particular direction and if this be true the bit can merely be lowered into the well and then spudded a suflicient amount to insure that a deflecting opening has been formed.

It will be obvious that the circulating liquid is discharged on the front face and tends to wash the formation away in the direction in which the deflection is to occur. This is of particular advantage in soft formations because it assists in the deflecting of the bit and removing the material in front of the bit.

Broadly the invention contemplates a bit by which a side tracking or deflecting operation can be readily performed and once the deflected opening is started thebit can be removed and the drilling of the well bore continued in an ordinary manner. While a cement plug has been shown as the deflecting body against which the bit will be moved, it is to be understood that any type of whipstock or other obstruction may be used.

What is claimed is:

l. A spudding bit including a body and a blade portion, interfitting shanks on said portions. a

pin passing through said shanks whereby said of thewell bore so that the cavitycan be thereafter used to deflect a rotary drilling bit which comprises in combination a string of drill pipe.

a bit head flxed to the lower end thereof, a' wedge like blade member connected to said head. said blade having a cutting edge which is a straight line, means to th: said blade in an ofl center position so as to divert the bit and form a cavity at an angle to the axis of the well bore when the blade is forced longitudinally into the bottom of the well bore, said means being adjustable-to predetermine the angle of deflection, and a discharge port for fluid on the outer face of said blade closely adjacent the cutting edge.

3. A deflecting tool for spudding in the bottom of a well bore to form a cavity inclined in a predetermined direction with respect to-the axis of the well bore so that the cavity can be thereafter used to deflect a rotary drilling bit which comprises in combination a string of drill pipe, a bit head flxed to the lower end thereof, a wedge like blade memberconnected to said head, said blade having a cutting edge which is a straight position so as to divert the bit and form a cavity at anangletotheaxisoithewellbore whenthe blade is forced longitudinally into the bottom of the well bore, said means being adjustable to predetermine the angle of deflection, a discharge port for fluid on the .outer face of said blade closely adjacent the cutting edge, and interconnecting passages thru said drill stem, bit head, and 'bladeto supply fluid to said port.

IRNIB'I L. M18.