US2542679A - Combination sub for drilling operations - Google Patents

Description

Feb. 20, 1951 a. E. KEMNITZ 2,542,679

cousmnon $08 FOR DRILLING opm'rxous Filed March 18, 1950 IN VEN TOR.

-2 GEORGE E KEMNITZ 1 z-31 BY M i kyn 1;

ATTORNEYS Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE- COMBINATION SUB FOR DRILLING v OPERATIONS George E. Kemnits, Tulsa, Okla., assignor to Noble Drilling Delaware Oorp., Tulsa, Okla.. a corporation oi Application March 18, 1950, Serial No. 150,531

- i This invention relates to well drilling tools and more particularly to novel "sub" constructions for use in retrieving "fishes" during drillingon each. These connectors are commonly referred to as subs. Often in the drilling of wells, the drill pipe becomes stuck, because of caving in of the hole or the settling of sand or other sediments, and it is freed by use of what is called "wash-over pipe.

It is conventional practice to disconnect or back off the tool Joint just above where the drill pipe is stuck, raise the disconnected parts out of the hole, apply a piece of wash-over pipe thereto, which may vary in length from a few feet to several hundred feet, go back into the hole, and wash over the stuck pipe by circulating drilling fluid through the'wash pipe and thus wash out the substance holding the stuck pipe. The wash-over pipe is, of course, of greater inside diameter than the outside diameter of the drill pipe. After a considerable section of the stuck pipe has been washed over, the wash pipe is again pulled out of the hole and disconnected. The drill pipe part to which it has been attached is then again lowered into the hole and connected with the washed over section of drill pipe. Then back off shot or "string shot is lowered into the thus connected drill pipe and stuck section.

This explosive string shot usually about 33 feet in length, a little longer than a length of drill pipe is lowered by electric wires inside the drill pipe to the lowest tool joint washed over. Left hand torque is applied to the drill pipe and the string shot is detonated. This has the effect of jarring the joint loose so that it will readily unscrew, being much the same as apply- 8 Claims. (01.294-86) of time is lost in this practice in the round trip of the pipe sections above the stuck pipe needed for disconnecting the wash pipe and then for going back into the well with the drill pipe for application of the string shot and for retrieving the fish.

Principal objects and features of this invention are the provision of a novel "combination sub construction to which wash pipe may be connected and which also has a connector that may be screwed into the freed section of the pipe after it has been washed over, and permits lowering and detonation of string shot so that the washed-over section of pipe may be backed off and pulled out of the well without the necessity of previously removing the wash pipe, thus eliminating one full round trip of the drill pipe for purposes of disconnecting the wash pipe, as presently practiced, and going back in to retrieve the fish.

Further objects and features of the invention are the provision of simple effective combination sub" constructions, applicable for use with existing drilling equipment, that are easy to use,

relatively low in cost and time saving in their use.

Other objects and novel featureswill become apparent from the following specification and accompanying drawings wherein similar reference characters denote corresponding parts and wherein:

. Fig. 1 is an elevational view of the device embodying the invention shown in position of 1186;

Fig. 2 is a longitudinal section taken along line 2-2 of Fig. l and viewed in the direction of the arrows;

Fig. 3 is a transverse section taken along line 3-3 of Fig. 2;

Fig. 4 is a fragmentary longitudinal section similar to that of Fig. 3, showing parts in another position; and

Fig. 5 is a longitudinal section similar to that of Fig. 3 of a modified form of construction.

Referring to the drawing, l0 denotes a hole being drilled by conventional drilling equipment D including drill pipe H the lowermost length Ha of which for purposes of this application is assumed to be the stuck pipe. The lengths of pipe II are strung together end to end being connected by conventional sub parts l2 and H41 in usual manner during actual drilling operations, the uppermost pipe being suspended from the head part l3 of the drilling equipment. The sub part I! in this disclosure is a female part 3 attached to the upper end of a drill pipe length while sub part In is a male part secured to the lower end of a drill pipe length.

The combination sub 8 embodying the invention, which is to be utilized whenever a drill pipe length becomes stuck comprises a tubular member I4 whose upper end has a threaded socket IS, the threads of which are adapted to be screwed onto the right hand threads II on the pin and of the regular sub part or tool joint I2a on the lower end of the drill pipe above the stuck section Ila. The portion II of the tubular member I4 below socket II is of substantially larger diameter than the drill pipe, and is threaded externally at I4 to receive threadedly a length of wash pipe II. A portion 20 below the externally threaded portion I4 of reduced diameter is also threaded externally at 20a for application thereto, if desirable, of wash pipe (not shown) of smaller diameter than wash pipe I9.

The lower part of the tubular member I4 is further reduced in diameter, at portion 2I tapered and provided with an external preferably square left-hand thread 22, that is, thread running in opposite direction to the threads I5.

Three segmental parts 22, 24, 25 internally tapered and threaded to fit on the left-hand thread 22 of portion 2| are threaded externally at 26 with a tool joint right-hand thread for connection with the standard threaded socket of the sub I2 carrying the stuck pipe section Ho. The parts 23, 24 and 25 are held in place on the portion H by snap rings 21, 28 fitting in the respective annular grooves 29, 30 in the parts 23, 24 and 25. Below the left-hand threaded portion 2|, the body I4 extends as a nose or head it having a largest external diameter 32 dimensioned to fit slidably in the internal diameter of the bore in sub I2 and a tapered leading part 33 to guide the head into the said bore.

In utilizing the combination sub assembly described when a drill pipe length IIa becomes stuck, the drill pipe above the stuck section is given clockwise rotation causing upper joint part In of the pipe length II just above the stuck section to be unscrewed from part I2 of the stuck section Ila. The detached pipe lengths including the just separated part In are drawn upwardly out of the hole I0. The combination sub S is then attached to the pin end It of the latter-named joint part He by screwing the socket I of member I4 onto the said threaded pin end IS. Wash pipe I9 is then screwed onto threaded portion I8 of body I4 or threaded part 20. The assembled parts are then lowered into the hole to the level of the stuck pipe Ila and wash water or drilling fluid sent down through the pipe lengths II and lower outlet end of the bore in body I4 at its nose 3|. The wash water acts to wash away cave-in or blocking or clogging material about the stuck pipe Ila and permit gradual lowering of the nose II of body I4 into the bore of sub I2 of the stuck pipe until the threaded parts 23, 24 and 25 lie alined with the threaded socket of this sub I2. The entire assembly is then rotated counterclockwise, or to the left. Friction between the threaded parts 23, 24 and 25 and the socket of the said sub I2, causes the threaded left-hand tapered portion 2I to screw into the socket defined by the internal threads of parts 22, 24, 25 and expand these parts causing their external threads to fit in and engage the right-hand threads of the socket of the said sub I2. After the string shot has been lowered and as left-handed or counterclockwise rotation is continued, left torque is appliedto the drill pipe Ila through the tubular part so that when the string shot" is detonated. the fish or pipe Ila is freed .and can be pulled up out or the hole without unscrewing the members 22, 24, 25 from sub I2.

Modification In the modified form of construction shown in Fig. 5, the essential diflerence is that only the externally threaded portion lib corresponding to threaded portion I8 is provided in the tubular part I4b. Likewise the nose SI of part I4 is replaced by a nose part III: on the end of part I 4b which performs the function of nose II of tubular member I4. Operation is substantially the same except that the device is limited to use of wash pipe of but a single diameter instead of permitting the use of differently diametered wash pipes in coniunction therewith.

While specific embodiments of the invention have been described and shown, variations in structural detail within the scope of the appended claims are possible and are contemplated. There is no intention, therefore, of limitation to the exact details shown and described.

7 What is claimed is:

l. A combination sub for use in hole drilling for the recovery of stuck tool parts comprising a tubular member having a threaded socket at one end for direct attachment to the conientional threads or a threaded pin end of a tool joint part, a portion having external threads for attachment thereto of a wash pipe, a tapered portion on said member having an external thread in reverse direction to the thread direction of the threaded pin end, a plurality of tapered sectional parts internally threaded to mate with the reversely directed external thread of said tapered portion mounted in assembled relationship on said last.

named thread, said tapered sectional parts bein tapered externally and provided with external conventionally directed threads to match the conventional thread of an internally threaded socket of a second tool joint part, said sectional parts being expansible to fit their external threads into threaded relationship with the internally threaded socket of said second tool joint part. upon rotation of said tapered portion in a direction to screw it into the internal threads of said sectional parts.

2. The combination of claim 1 in which the tubular member has a nose part for guiding the sectional parts into the internally threaded socket of said second tool joint part.

3. The combination of claim 1 in which snap rings mounted on said sectional parts hold them expansibly in assembled relationship on said tapered portion of said tubular member.

4. The combination of claim 1 in which said sectional parts have grooves and in which snap rings fitting within the grooves hold said sectional parts expansibly in assembled relationship on said tapered portion of said tubular member.

5. The combination of claim 1 in which said sectional parts have end portions shaped to define a guiding nose to facilitate guiding of the assembled sectional parts on said tapered portion into the internally threaded socket of said second tool joint part.

6. The combination of claim 1 in which the external conventionally directed threads are right hand threads and in which the external thread on said tapered portion i aleft handed thread.

a portion having external threads for attachment thereto of a wash pipe, a second portion of different diameter having external conventionally directed threads for attachment thereto or a different diametered wash pipe, a tapered portion on said member having an external thread in reverse direction to the thread direction of the threaded pin end, a plurality of tapered ectional parts internally threaded to mate with the reversely directed external thread of said tapered portion mounted in assembled relationship on said last named thread, said tapered sectional parts being tapered externally and provided with external conventionally directed threads to match the conventional thread of an internally threaded socket of a second tool joint part, said sectional parts being expansible to fit their external threads into threaded relationship with the internally threaded socket of said second tool joint part,

upon rotation of said tapered portion in a direction to screw it into the internal threads of said sectional parts.

8. A combinationsub for use in hole drilling comprising a tubular member having a threaded socket at one end for attachment to a threaded pin end of a tool joint part, a threaded external portion for attachment thereto, of a wash pipe,

a tapered portion provided with a thread of reverse direction to that of the first named threaded portion, a plurality of internally threaded tapered parts mounted in assembled relationship on the reverse thread of said tapered portion, expansible means for holding said parts on said threaded tapered portion, said internally threaded tapered parts being externally threaded to match No references cited.

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