US1739928A - Core drill - Google Patents

Description

Dec. 17, 1929.- B. D. THOMPSON CORE DRILL Filed Nov. 17. 1928 ATTORNYS wf @Zag/afm Patented Dec. 17, 1929 UNITED STATES PATENT OFFICE GORE DRILL Application led November 17, 1928. Serial No. 920,182.

The invention relates to core drills for taking samples of earth formations and consists in the features and combination and arrangement of parts hereinafter described and particularly pointed out in the appended claim.

In the 'accompanying drawings Figure 1 is a vertical sectional view of my improved drill.

Fig. 2 is a detail view. Fig. 3- is a sectional view on line 3-3 of Fig. 1.

Figs. 4 and 5 are detail views. The invention includes a suitable cutter 1 adapted to rest on the bottom of the well. This cutter consists of a hollow shell having a tooth formation at its lower end adapted to cutthe formation so as to leave a core of said formation indicated at a of less diameter than the interior of the Shell thus leaving an annular channel 3 about the core and between it` and the shell 2 for the upflow of the detritus or so-called sand pumpings as will hereinafter be referred to.

For this ypurpose the teeth of the cutter are wide at their lower ends to cut a path wider than the thickness of the shell to provide the clearance around the core memtioned above, and also to cut clearance around the outside of theshell and between it and the wall of the hole for the circulation of the detritus or sand pumpings. The cutter shell is attached by screw threads to a tube 3*, which at its upper end is screw threaded to a block 4 having a vertical bore orport 5 which at its upper end has a Hap valve 6, secured at 7 so that it may open upwardly for the passage of thev detritus up through port 5, but said valve prevents downward 1)assage of material through said port.

L The block 4 has a tube 8 screw threaded the-reto said tube being screw threaded at its upper end into connection with a block 9 forming a part of a stuffing box 16. Another tubing section 11 is screw threaded to the block 9 of the stufiing box and this tube section at its upper end is screw threaded to ahead 12. Within the tubular casing or member 8 a piston 13 is mounted to reciprocate vertically and without undue friction.

This piston has ports 14 extending verlthrough the head 12. It is provided at its tically therethrough controlled by downwardly closing valves 14". The plston rod 15 extends up through the stuffing box and upper end with any suitable means for atu tachment to an element or means for reciproeating it such as are usual on the derrick of earth drilling rigs. At a point near the upper end of the tubing 8 and under the stuffing box 9 lateral ports 16 are formed through the sa1d tubing for the discharge outwardly therethrough of the detritus or sand pumpings. In the operation of the apparatus as thus far described,.we will suppose that rotary step by step movement is given to the tool as it rests upon the bottom of the hole. Means for imparting this rotary motion will be later referred to. The teeth of the cutter will, therefore, cut the formation, while it mamtains itself by its weight upon the bottom of the hole. During this cutting operatlon the piston will be reci rocated vertically by suitable means attac ed to the upper end of the piston rod with the result that the 75 d etritus and sand pumpings will be continuously drawn away' from the teeth of the cutter upV through the annular channel surrounding the core, past valve 6, through the piston and out through the openings 10, so that the cutting edge will be kept clear of cuttings and will perform its cutting action on the virgin formation instead of yreacting on the detritus already produced by the cutting teeth. This flow of the detritus will be due to the action of the piston which when it goes up will draw the material up past valve 6, at the same time forcing out through the ports 10 any material which lies above it. On the down stroke the valve 6 will close and the piston valves will open allowing the material to get above the piston so that on the next A upstroke of the piston the material will be forced out through the ports 10. In this way the cutting teeth are constantly cleared of cuttings thus enabling lthe teeth to act directly on the formation to be out with eficiency. I

The lateral openings 10 lie above the upper limit of movement of the piston so that they Ag c Y 1,739,928

are always free for the discharge of material therethrough.

I stated above that the tool may be rotated by any suitable means. In the form of my invention, which I have chosen for its illustration, I employ teeth :v on the interior of the head 12 to be engaged by pawls y pivotally mounted at e in adisc A and arranged when the disc is rotated one way tov cause the pawls v lo by engaging the teeth to rotate the head and the tubin and cutters. This disc has a pin 18 exten ng into a groove 17 in the piston rod.. Said groove extends spirally of the rod and as the rod moves up` and down it rotates the'disc irst one way and then the other by the walls of the groove acting as cam surfaces against the pin 18. When the disc rotates one way it turns the apparatus throughthe pawl and ratchet connection, and

g0when the disc turns in the other direction the pawls ve or turn-on their pivots and move along ie inner side ofthe head without rotating it. The pawls thus engage new teeth and on the next forward movement they turn as the head together with the tubing and cutter another step forwardly. It will be noticed that the ratchet mechanism is located in the cavity of the head member 12 above'a block 2O fixed on the interior ofthe tubing.

$0 On the piston rod at a point above the stuing box a collar or enlargement 21 is 1ocated. When the apparatus isto'be withdrawn from the well the piston rod is raised until the collar strikes themember I sey 86 lcured within the tubing and then continued upward movement of the piston rod will draw the apparatus out of the well.

' At b I show grips representative of any suitable form for grasping the core and breakl 40 ing and lifting it when the apparatus is drawn up out of the well.l I claim:

In combination a tube having teeth at its lower end to out the formation at the bottom 5 vof the hole when the tool is rotated, a block within the tube having a Apassage therethrough for the upilow of fluid and detritus, a valve closing downwardly and controlling said passage, a stuiing box in the tube above y said block, apiston working in the tube inter'- mediate of said block and stuing box, said piston havin valve means to permit upward flow of the uid and detritus, and to raise said fluid and detritus, said tube having a 56 discharge port leadingto the outside oftheI said tube at a point below said stuiiing box and above the piston when lowered, a piston rod extending up from the piston and through 'the upper part of the tube andl means for ro- Q6 tating the tube, said -means being operated from the reciprocations of the piston rod, substantially as described.

' In testimony whereof I aix my signature v BURCHARD D. THOMPSON

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