US1999428A - Core taking apparatus - Google Patents

Description

prall 3U, H935. F. THRIFT E999y428 CORE TAKING APPARATUS Filed March 27, 1955 Patented Apr. 30, 1935 IUNITED STATES PATENT o1=1=1cl.:'fv

CORE TAKING APPARATUS Fred Thrift, Campbellton, Tex.

Application March 27,

3 Claims.

This invention relates to core taking apparatus. An object of the invention is to provide apparatus of the character described for taking cores or samples of the formation encountered during well drilling operations and embodies a core barrel with novel means whereby the same may'be securely landed in position in, and securely maintained in position in, the drilling apparatus.

Another object is to provide novel means for locking the core barrel in position which may be readily released when it is desired to withdraw the core barrel.

A further object is to provide, in a device of the character described, a novel construction whereby the drilling uid may be utilized to force the core barrel into its final position in the drill stem and drill and whereby the pressure of the drilling uid is released when the core barrel has landed in home position to indicate to the operator that the apparatus is in position for taking a core or sample.

Another object of the invention is to provide a sample taking device that may be readily lowered into and withdrawn from the drilling apparatus without withdrawing said -drilling apparatus from the Well. Y

With the above and other objects in view the invention has particular relation to certain novel features of construction, operation and arrangement of parts an example of which is given in this specification and illustrated in the accom panying drawing wherein:

Figure 1 shows a fragmentary vertical sectional view of a drill stem showing the upper end of the core taking apparatus therein.

Figure 2 shows a vertical sectional view of the intermediate portion thereof, and

Figure 3 shows a vertical sectional view of the drill as attached to the lower end of the drill stem showing the lower end of the core barrel in home position therein.

Referring now more particularly to the drawing wherein like numerals of reference designate similar parts in each of the figures, the numeral 1 designates a tubular drill stem whose sections are connected by suitable tool joints as 2 and attached to the lower. end o f the drill stem there is a drill 3 of any conventional construction and having an axial bore 4 through the lower end thereof for the inlet of thev sample. Above its lower end the bore 4 is reduced in diameter forming the seat 5 to receive and support the lower end of the tubular core` barrel 6. The lower end of the core barrel has sample retaining means 1933, serial No. 663,054

(ci. Z55- 72) of any conventional construction. As shown the core retaining means comprise exible fingers 'l whose lower ends are secured to the lower end of the core barrel and whose upper ends are curved inwardly.

'Ihere is a stem 8 whose lower end is enlarged forming the plunger 9 and the lowe:` end of this plunger is connected to the'upper end of said..y barrel preferably by threads. This plunger andv the upper end of said barrel t closely within the cylinder I0 whose upper end is screwed into the tool joint above. Beneath the upper end of the core barrel, said barrel is provided with the lateral openings II and within the barrel beneath said openingsz there is the annular valve seat I2 pinned in said barrel by the pin I3 or otherwise secured therein. The seat is normally closed by means of the upwardly opening ball valve I4. v

The upper end of the stem 8 is enlarged and formed into an anchor I5, which is slidable` in the trip sleeve I6. The lower end of this sleeve has the vertically elongated slots I'l, I1 and a pin I8 extends through said anchor and its ends lmove in said slots. The upper end of the anchor I5 has an upwardly diverging bearing I9 which terminates in the transverse slot 20 through said anchor. There are the upwardly diverging flexible dogs 2|, 2I whose lower ends are seated in said bearing and pinned therein by the pin 22 and whose upper ends diverge out through said slot 20. A coil spring 23 is located between the upper ends of said dogs.

The numeral 24 designatesa rod whose lower end is formed into a plunger 25 which ts closely within the cylinder 26, which is attached to and depends from the tool joint above. 'Ihe lower end of the plunger 25 `is connected to the upper end of the sleeve I6 in any suitable manner, preferably by threads.

The upper end of the rod 24 is formed with a conical shaped-head 21 for a purpose to be hereafter stated.

The lower` .end 'of the cylinder 26 is provided with an internal annular downwardly facing shoulder 28.

In carrying on drilling operations when it is desired to take the core, the core taking apparatus may beasseinbledas shown and a suitable grapple attached to .the head 2l and the apparatus let down through the drill stem by means of a cable attached to the-grapple. The lower end of the core barrel 6 will enter the enlarged upper end of the bore 4 and the plungers will enter the corresponding tool joints 2 and the drilling iiuid above under pump pressure will force said plunger downwardly through the cylinders. While the coring apparatus is being so lowered the pin I8-will hang on the lower ends of theslots I1 and if for any reason the lower end of the core barrel 6 should hang in the bore 4, the pressure of the uid above the plunger 25 will force said plunger downwardly, the sleeve I6 moving downwardly on the anchor I6 until the upper ends of the slots I1 engage the ends of the pin I8 and the stem 8 and barrel 6 will be forced further down until the core barrel is forced into home position whereupon the plungers 25 and 9 will clear the respective outlet ports 29, 30 in the respective cylinders 26, and I 0. Thereupon the pressure being released kthe pump will speed up indicating that thecore barrel has landed on the seat 5.

While the coring apparatus is being lowered, the sleeve 'I6 will be in its upper position relative to the anchor I5 as hereinabove indicated and the spring dogs 2I will be thereby held in inner, or retracted, position, lbut when the sleeve I6 has been moved downwardly relative to the' anchor I5, as above indicated, the slot 20 will align with the side slots 3|, 3I, through the sleeve I6 and the upper ends of the dogs 2|, 2I will be projected through and beyond said slots 3| and when said upper ends clear the shoulder 28 they will engage underneath the shoulder 28, to lock said core barrel in place.

The grapple may then be detached from the head 21 and the cable removed and drilling may then be proceeded with. A core or sample of the formation will enter the bore 4 and pass up into the core barrel above. -Any liquid that may be in said core `barrel will pass out through the seat I2 the valve I4 lifting for that purpose and said liquid will pass on out through Vthe openings II. While the core is being taken drilling fluid will be forced under pressure down through the drill stem and will pass out through the channels 32, 32 which lead from said drill stem and diverge through the drill 3 whereby flushing fluid is discharged in front of the respective cutter blades, or other cutters 33, 33 .1

The lower end of the drill may be formed with a pilot core bit 34 of any selected design.

When a core or sample has been taken the grapple may be again lowered as before andengaged over the head 21. An upward pull on the cable will cause the sleeve I6 to move upwardly relative to the anchor I5 and the upward moveto the ground surface for an inspection of the core.

The drawing and description discloses what is now considered to be a preferred form of the invention by way of illustration only while the broad principle of the invention will be defined by the appended claims.

What I claim is:

l. A core taking apparatus comprising a tubular drill stem having a drilling tool at the lower end thereof provided with an axial bore having an upwardly facing seat, spaced cylinders in the stem each having an inlet, a core barrel in the stem whose lower end is adapted to rest on said seat, spaced plungers connected to the barrel arranged to enter said cylinders as the barrel is lowered, said plungers forming means by which the barrel may be forced downwardly onto said seat by the pressure of the drilling fluid above and being arranged to clear said inlets when in home position.

2. A sample taking apparatus comprising a tubular drill stem having upper and lower cylinders therein, a drill on the lower end of said stem having an inlet for the entrance of a sample, a core barrel shaped to be lowered through said stem and cylinders into cooperating relation with the drill and into alignment with the inlet, plungers connected with saidbarrel and arranged to enter the respective cylinders as the barrel approaches its final position in the stem whereby pressure fluid in the stem above the plungers may be rendered effective to force the barrel downwardly to its final position, each cylinder having an outlet port and said plungers being positioned to clear said ports to release said pressure when the barrel reaches said nal position.

3. A sample taking apparatus comprising a tubular drill stem having upper and lower cylinders therein, a drill on the lower end of said stem having an inlet for the entrance of a sample, a core barrel shaped to be lowered through said stem and cylinders into cooperating relation with the drill and into alignment with the inlet, plungers connected with said barrel and arranged to enter and completely close the respective cylinders as the barrel approaches its final position in the stem whereby pressure uid in the stem above the plungers may be rendered effective to force the barrel downwardly to its nal position, said plungers having a slip joint connection formed with relatively movable parts and interengaging means carried by said stem and connection respectively and normally locking the barrel in the stem, said locking means being arranged to be released upon the relative movement of said parts.

FRED THRIFI.

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