US2331553A - Coring apparatus - Google Patents

Description

1943- J. E. HOFFOSS E'IV'AL 2,331,553

CORING AiPARATUS Filed June 1 1942 Z 2: 2 277-; O/PA/k Patented Oct. 12,1943 I UNITED STATES PATENT OFFICE coame mmrus John E. Hoil'oss and John C. Stokes, Houston, Tex., assignors to Reed Roller B Company, Houston, Tex a corporation of Texas Application June 1, 1942, Serial No. 445,274 4 Claims. (Cl. 255-72) This invention relates in general to'coring apparatus and more particularly has for its general object the provision of a coring apparatus of the type known as a wireline coring appa ratus in which there will be embodied an improved holddown mechanism for the core barrel in combination with an improved mechanism for driving the-core barrel or causing it to rotate with the core bit.

Another object of this invention is to provide a driving mechanism for driving a wireline core barrel which mechanism will be entirely separate and independent from the means for holding the core barrel down.

Another object of this invention is to provide a driving mechanism for a wireline core barrel which mechanism may be located adjacent the lower end of the core barrel thus avoiding the necessity of transmitting torque from the lower end of the core barrel to the upper end thereof.

Another object of this invention is to provide a driving mechanism for a wireline core barrel which mechanism will be simple to construct, easy to install, and positive in its operation.

Another object of this invention is to provide a driving mechanism for a wireline core barrel which mechanism will permit the downward passage of the core barrel until it seats in core taking position within the core bit, without necessity for the core barrel to rotate one way or the other in order to fit into the driving mechanism as it moves downward to its seat.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawing in which is set forth by way of illustration and example one embodiment of this invention.

In the drawing:

Fig. 1 is a view partly in side elevation and partly in vertical cross section illustrating the upper end of a core barrel having a holddown mechanism constructed in accordance with this invention.

Fig. 2 is a view in longitudinal cross section illustrating a core barrel constructed in accordance with this invention in place within a core bit, with the driving mechanism for the core barrel in place therein.

Fig. 3 is a longitudinal cross section showing a fragmentary portion of the structure illustrated in Fig. 1 and taken along the line 3-3 of Fig. 1.

Fig. 4 is a transverse cross section taken along the line 4-4 of Fig. 1.

the wireline core barrel illustrated consists of an upper barrel I having a fitting 2 welded at 3 or otherwise secured to the lower end thereof, and having a lower core barrel 4 threaded at 5 to the lower end of the fitting 2. The lower end of this lower core barrel is threaded to receive the protruding cutter head 6. The cutter head 6 is formed with a part of its inner surface of larger diameter so as to receive the core catcher structure 9. The core bit may be of any conventional form and in this instance is shown as being of the drag type having blades E.

On its upper end, the upper core barrel carries a fitting H which may be welded or otherwise secured thereto as shown at l2, and threaded on to this fitting is the valve cage l3 having a ball valve I4 disposed therein. The ball valve I4 is adapted to seat upon a valve seat I5 held in place by means of a nut l6 or the like. The valve cage I3 is provided with lateral openings I! so that fluid may fiow upwardly from within the core barrel past the ball valve. l4 and out through the openings H. No fiow can take place inwardly through the openings l1 and into the core barrel, however, because of the action of the ball valve l4 which acts as a check valve. The valve cage l3 has a part integral therewith which extends upwardly and is provided with a through slot l8 adapted to receive the holddown shoes l9 and 20 which fit side by side within the slot l8 and have gripping teeth 2| extending in opposite directions outwardly from the body of the valve cage. Each of these shoes l9 and 20 has a slot 22 extending at an angle to its gripping surface adjacent its lowerend and a slot 23 of similar size and angle but extending in the opposite angular direction with respect to the gripping face of the dog.

The upward extension of the valve cage I3 is also provided with a longitudinal bore adapted to receive a plunger 24 the lower end of which is bifurcated to straddle the upper portions of the dogs 20 and 2 I, as shown at 25. This plunger 24 is normally urged in an upward direction by means of a spring 26 that surrounds the plunger above the upper end of the body I 3 and bears at itsjupper end against the enlargement 21 on the plunger 24. The upper end of the plunger 24 may be provided with a spear head 28 adapted tobe engaged by an overshot of the type customarily employed for removing wireline core barrels from drill stems.

Extending through each of the two lower slots 22 in the respective dogs I! and and having its opposite ends anchored in the body i3 is a pin 29. A similar pin 30 extends through the slots 23 in the two shoes I9 and 20 and has its opposite ends anchored as shown at 3| in the bifurcated lower portion of the plunger 24.

It will readily be seen that the plunger 24 is normally urged in an upward direction by the spring 26 and when in its upper position the plunger will hold the pin 30 in an upward position with respect to the slots 23 and thus move the upper ends of the shoes or dogs I! and 20 inwardly to disengage the teeth 2| from the inner surface of the drill collar or other portion of the drill stem. At the same time, this upward movement of the plunger will cause an upward movement of both of the shoes I! and 20 with respect to the pin 29, and this will serve to retract the lower ends of these shoes from their frictional engagement with the drill collar or the like. On the other hand, it is contemplated that when slush is pumped downwardly through the drill stem it will impinge upon the enlargement 21 on the plunger 24 and force this plunger downwardly so as to move the pin 30 downwardly and so as to move the shoes I! and 20 downwardly with respect to the pin 29 so that the teeth 2| on both of these shoes will be moved outwardly so as to provide a frictional engagement between these shoes and the inner wall of the drill collar. The core barrel will thus be frictionally held down during the taking of a core.

Referring again to the lower core barrel, the same is provided with milled slots or grooves forming a splined arrangement at an intermediate portion thereof. This is clearly illustrated by the numeral 32.

Threadedly connected to the upper end of the drill bit 8 is a fitting 33, this fitting being additionally internally threaded at its lower end to receive a nut ll. This nut 30 has grooves formed in its outer surface for the purpose of receiving the end portions 35 of the driving springs 36. It will be noted that the end portions 35 have their upper ends 31 turned inwardly and fitting into proper cut away portions of the nut 3|. These springs are bent around the lower end of the nut and have an upwardly and inwardly inclined portion 38 joined to the main driving portion 36 which extends directly upwardly, and the upper end of this main driving portion 36 has an upwardly and outwardly inclined portion 39.

It will readily be seen that when the core barrel just described is dropped into place, its lower end will come in contact with the upper outupon, the core barrel will be locked against rotation with respect to the core drill and the core may be taken while the core barrel is held against rotation with respect to the core drill.

It will be understood that while this invention has been described in connection with a core barrel having a protruding cutter'head on its lower end, it may be used as well in connection with a barrel adapted to seat in-a core bit, the bit itself carrying the teeth which cut the core.

It will be appreciated that a means has been provided for carrying out and accomplishing all of the advantages sought by this invention.

Having described our invention, we claim:

1. In a wireline coring apparatus, a drill stem, a core drill thereon, a core barrel adapted to be lowered into the drill stem and core drill, means on the core barrel adapted to expand and frictionally engage the inner surface of the drill stem to hold the core barrel against upward movement therein, splines formed on the core barrel, and resilient means carried by the drill stem and adapted to engage said splines to hold the core barrel against rotation with respect to the drill stem.

2. In a wireline coring apparatus, a drill stem including 'a tubular member, a core drill on said 1 drill stem, a core barrel comprising a second tubuwardly inclined portions 3! of the driving springs bit I, if the driving springs I. are not already seated within the splines 32 on the lower core barrel, the core barrel may rotate slightly with respect to the core drill untilsuch time as the springs I do engage with the said splines. Therelar member adapted to be lowered into the drill stem and core drill, means on one of said tubular members adapted to move in a radial direction to frictionally engage the surface of the other of said tubular members to hold the core barrel against upward movement within the drill stem, splines formed on one of said tubular members, and resilient means carried by the other of said tubular members and adapted to engage said splines to hold the core barrel against rotation with respect to the drill stem.

3. In a wireline coring apparatus, a drill stem, a core. drill thereon, a core barrel adapted to be lowered into the drill stem and core drill, splines formed on the core barrel, and a leaf spring extending in a longitudinal direction with respect to the core barrel along the inner surface of the drill stem and having an intermediate portion spaced from the interior of the drill stem, the end portions of said spring having their inner surfaces inclined outwardly so that the core barrel may pass downwardly past the spring and cause it to flex outwardly except when said spring engages one of said splines, whereby said spring may engage one of said splines to hold the core barrel against rotation with respect to the drill stem.

4. In a wireline coring apparatus, a drill stem, a core drill thereon, a core barrel adapted to be lowered into the drill stem and core drill, splines formed on the core barrel, an annular member carried'within said drill stem, and a spring key carried by said annular member and having a portion disposed between said annular member and the inner surface of the drill stem, and another portion extending through said annular member to engage one of said splines, said last mentioned portion being inclined away from the central portion of the drill stem adjacent its two opposite ends.

JOHN E. HOFFOSS. JOHN C. STOKES.

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