US1844257A - Slip joint for drill stems - Google Patents

Description

Feb. 9, 1932. R. A. LINCOLN 1,844,257

SLIP JOINT FOR DRILL STEMS Filed March 9, 1929 BY HQ A TTORVE Y Patented Feb. 9, 1932 UNITED STATES nomm'r a. LINCOLN, or wrcnrra FALLS, 'rnxns BLIP JOINT FOB DRILL STEHS Application fled larch 8, 1929. Serial No. 845,688.

My invention relates to a device to be placed in drill stem employed m well drillmg which will enable the driller to place a continuous and equal weight upon the drill 6 durin the drilling operation.

- In deep well drilling for oil, gas, sulphur, and the like, the drill is found to run smoother and more effectively if an equal and steady weight is allowed to rest upon the drill. This weight should not be too heavy but it should be sifiicient to exert a thrust upon the bit sufi :ient to force it into the formation WhlCh is l" eing drilled. The diificulty is to keep the weight uniform and to prevent the weight 1 from becoming excessive. The total weight of the drill stem above a drill bit is sometimes far greater than the bit is enabled to su port.

t is an object of my invention to prov1 de a slip joint in the drill stem WhlCh w1ll enable the driller to suspend the upper portion of the drill stem from the derrick platform and to allow only the lower portion of the drill stem to rest upon the b1t so that the weight of the pipe supported by the drill stem can be accurately determined and adjusted.

It is a further object 1n devices of this kind to provide a slip joint which may be 0 adjusted to prevent relative sliding movement of the two parts of the drill stem whlle the drill is being inserted into the well but which is capable of release when the'drill stem is rotated with the drill upon the bottom of the hole.

It is a further object to provlde effective means to revent the u per and lower sections of t e drill stem rom becoming connected again during the drilling operations.

The invention lies largely in the particular construction and arrangement of the parts making up the improved tool and reference is made to the drawings herewith wherein a preferred embodiment thereof is disclosed.

In the drawings, Fig. 1 illustrates a central longitudinal section throu h the joint forming the subject matter 0 my invention.

Fig. 2 is a transverse section, somewhat is threaded at, 2 for engagement with a collar or tool joint 3, which in turn is connected with the joint at the lower end of the upper section of the drill stem. The barrel 1 is of any length but ordinarily a section of about 20 or 22 feet in length is preferred as this allows the telescoping of the joint for a full section of drill stem. The lower end of the barrel is threaded for connection at 4 with a special coupling 5.

The coupling 5 is secured to the lower end of the barrel and its inner diameter is decreased to form a shoulder 6 above which it, isthreaded at 7 for engagement with the head 8 on the drive stem 9. The lower end of the nipple 5 is threaded at 10 to receive the bushing 11.

The bushing 11 is provided with a threaded portion 12 to engage within the threaded seat 10 of the nipple 5 and above the threaded portion the diameter is decreased and formed into an upwardly extending sleeve 13 to telescope within the nipple 5. The lower end of the bushing 11 has a head 14 thereon for engagement with a wrench or other tool by means of which it may be unscrewed from the nip le 5v The drive stem 9 is ormed to fit within the bushing 11 and has a plurality of radially extending keys or splines 15 to fit within corresponding keyways 16 1;" the bushing 11. This will be noted front-Fig. 2; I have shown four splines upon the drivestem .9 engaging within the bushing, but any desired number may be used. This engagement between the stem and the bushing allows a telescopic movement between the parts, but prevents relative rotation. The lower end of the drive stem is formed with a tool joint pin 17 thereon to engage within the lower section of drill stem, but it is to be understood that any type of coupling between the stem and the tool joint below may be employed.

The upper end of the drive stem 9 is threaded to engage within the head 8, which is adapted tobe screwed thereon, said head being threaded externally at its lower .end

for engagment at 7 with the nipple 5. Above,

the head 8, I provide packing means to form a fluid tight contact with the interior of the barrel 1. This packing device is shown as being made up of an upper cup 18, which is directed upwardly toprevent the passa e of fluid downwardly past the packing. 1S packing ring is separated from a second lower packing ring 19 by a spacer 20. The lower acking ring is directed downwardly as will be noted from the drawings. ,Above and below the two packing rings thus mounted are washers 21 and the entire packing assembly thus constructed is held in place b a lock .nut 22 threaded upon the upper en of the drive stem. .It will be noted that the head 8, together with the packin members, comprise a sort of piston slidab e within the barrel 1 when the ead 8 is disengaged from the ni ple 5.

t is to be understood that. the drive stem 9 is of the same or slightly greater length than is the barrel 1 so that the head 8 may slide upwardly in the barrel for approxmately the full length of said barrel. The interior of the drive stem 9 is formed with a water passage 23 so that fluid may pass downwardly through the joint during the operation of the drill.

When the device is to be introduced into the well, the lower section of the drill stem is connected to the joint 17, the drill being at the lower end of the drill stem. The bushing 11 and the head 8 are threaded into the nipple 5, approximately as shown in Fig. 1, and the upper section of the drill stem is connect ed with the barrel 1, as previously noted. As the device is introduce into the well 1t will be possible to force the drill downwardly to the bottom of the well without telescoping the joint between the drive stem 9 and the barrel 1. If obstacles are encountered during the introduction of the drill into the well the fluid circulation through the drill will be suilicient, with a slight rotation thereof, to force the drill past such obstacles until the bottom of the well is reached.

When the drill is upon the bottom of the hole the drill stem will then be rotated. This rotation communicated to the upper section of the drill stem will rotate the barrel 1 and the nipple 5 to screw said nipple downwardly upon the bushing 11. This will also screw the said nipple off of the head 8 on the drive stem.

When the head 8 has been disconnected in this manner it is free to slide upwardly in the barrel 1, and due to the fact that the coupling 5 is screwed down over the bushing 11 the upper gortion 13 of the bushing will project upwar ly past the threaded seat 7 and prevent the head 8 from again being screwed into the seat 7. With the parts thus discon nected the upper section of the drill stem may first allow the upper section of the drill stem to drop downwardly over the drive stem 9 until the parts are entirely telescoped together, then by supporting the upper section rom the derrick and rotatin" t e drill, the progress of the drill downwardly through the formation will cause -it to adually move downwardly relative to the arrel 1 until it has drilled a sufiicient depth to allow the insertion of another section of drill stem at the upper end of the string. When this is done, the parts will be again telescoped together and the o eration repeated.

It will e seen that by my device a uniform weight will be supported upon the drill at all times so that best results may be obtained. It will be determined by the driller through experiment exactly what weight of drill stem is most effective in the operation of the drill and the joint may be located in the string at tlaie proper point to obtain the. weight desire The advantages of my construction lie in the fact that the parts can not telescope together durin the introduction of the drill stem into the ole, due to the manner in which they are connected during thetime the drill is being inserted to the bottom. Thus if an obstruction is encountered in the well which might tend to cause the upper and lower sections at each side of the 'oint to be telescoped together they will be he d from so doing by my connection. This will prevent the accidents which are liable to hap en from telescopic joints in the drill stem, ue to the dropping of the lower section of stem away from the u per one after the obstruction is passed. Furt ermore, it will be impossible to make the connection between the head 8 and nipple 5 during the drilling operation, due to the osition of the bushing 11 when the parts are 'sconnected. The further advanta es of the device will be obvious to those ski ed in the art.

What I claim as new is;

1. A slip joint for drill pipe including two sections, one slidable relative to the other, means on one section enga eable by means on the other to hold the sa1d sections from relative longitudinal movement releasable on relative rotation, and means to thereafter prevent similar engagement of said sections.

2. In a drill pipe, a slip joint including a barrel a drive stem, a piston head thereon slidable in said barrel, a nip le on said barrel, a bushing engageable in sai nipple, and nonrotatably engaging said drive stem.

3. In a drill pipe, a slip joint including a barrel, a drive stem, a piston head thereon slidable in said barrel, a n1p le on said barrel, a bushing engageable in sai nipple and nonrotatably engaging said drive stem, said head being releasably connected with said nipple.

4. In a drill pipe, a slip joint including a barrel, a drive stem, a piston head thereon slidable in said barrel, a nipple on said barrel, a bushing engageable in said nipple and nonrotatably engaging said drive stem, said head being screwed into connection with said nipple and releasable on rotation of said pipe.

5. In a drill pipe, a slip joint including a barrel, a drive stem, a plston head thereon slidable in said barrel, a nipple on said barrel, a bushing engageable in said nipple and nonrotatably engaging said drive stem, said head having a threaded connection with said nipple releasable on rotation of said drill pipe relative to said stem, and means to thereafter prevent engagement of said threaded connection.

In testimony whereof I hereunto aflix my signature this 4th dagof March, A. D. 1929.

ROB RT A.- LINCOLN.

Images