US1908762A

US1908762A - Cut-off valve for drill stems

Info

Publication number: US1908762A
Authority: US
Inventors: Edgar C Johnston; Jr John F Fowler
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-09-04
Filing date: 1931-09-04
Publication date: 1933-05-16
Anticipated expiration: 1950-05-16

Description

May y16, 1933.

E. C. JOHNSTON ET AL CUT-OFF VALVE FOR DRILL STEMS Filed sept. 4, 1951 F' EDGAR CJOHNSTON E 3 JOHNFFWLER JR.

INvENToRa @im f5` @uk ATTORNEYS.

Patented May 16, 1933 UNITED STATES PATENT OFFICE EDGAR C. JOHNSTON AND JOHN F. FOWLER, JR., OF LONGVIEW, TEXAS cU'r-orr VALVE For. :DRILL straus Application led September 4, 1931. Serial No. 561,138.

.adjacent the cutting face of the bit. This mud then carries awa the cuttings from the bit and flows upwar y around the outside of the drill stem. Another purpose of this circulation is to mud-in the walls o the formation and prevent caving, and it is usual to make this mud quite heavy so that the walls of the well bore will be maintained.

VThe present invention contemplates the use of a device which will advise the 'driller almost instantly when the drill bit deviates from the vertical, and this device is of the type which will cut off the circulation of the Huid passing through the drill stemwhen the drill bit deviates from the vertical.

The circulation of mud is accomplished by means of slush pumps, and when the circulation is stopped for some reason, these' pumps will stall because the pressure required to maintain the circulation isv greater than the capacity of the pump. The driller realizes instantly when the pumps stall that circulation has been stopped, and the present invention uses a device to cut oil the circulation when the drill bit deviates from the ver tical so that the driller is advised by the stalling of his pumps that his bit has deviated from the vertical more than a predetermined angle. n Y l One of the objects of the invention is to provide a means and method of instantly advising the driller when the drill bit deviates from the vertical.

Another object of the invention is to provide a means of detecting drill bit deviation by controlling the circulation of flushing fluid in the well in such a manner that the circulation will be restricted or cut oli' when the bit deviates` beyond a predetermined angle with respect to the vertical.

, A still further object of the invention is to provide a coupling for drill stems containing a gravity actuated valve, which is arranged to cutJ 0E the iiow of fluid through the tool joint when the tool oint is inclined with respectto the vertical.

It is also an object of the invention to provide an oscilllatable member in combination with a tool joint or drill collar so that the flow of fluid through the drill bit will be restricted when thebit assumes an inclination with respect to the vertical.

Other and further objects of the invention will be readily apparent to those skilled in the art, when the following description is considered in connection with the accompanying drawing, wherein :l

Figure l is a central vertical Section through the tool joint or drill stem cable, which has been equipped with the invention.

Figure 2 is a section taken on the line 2-2 of Figure l, and looking in the direction of the arrows.

Figure 3 is a broken sectional View showing certain parts o-the invention in elevation, and certain parts in section, and illustrating the invention as applied to a drill bit positionedv in the well bore.

The drill stem lused in drilling the .well is indicated generally at 2, and extends t0 the surface of the eartli. This drill stern is connected by tool joints or couplings, and carries the drill bit 4 on its lower end. In some instances a tool joint or drill collar is used to couple the drill stem and bit together, and it is contemplated that this invention may be incorporated in a tool joint or drill collar used adjacent the top of the drill bit. Such a drill collar or tool joint is indicated in Figure 3 at 5, and shows the relationship of the device to the remaining parts of the drilling equipment. It is understood that the drilling of the well is accomplished by the rotation of the stem 2,

drill collar 5 is shown as being formed to receive an upper bushing 7 and a lower bushing 8. These bushings are preferably threaded in the tool joint 5 from opposite directions and are retained in position by the threads 9 formed on the tool joints and the bushings. The

bushings

7 and 8 are arranged to abut with each other at 10, and in this manner, serve as lock nuts for each other to insure that they will remain in position. Depressions 11 are provided in each of the bushings toY receive a Spanner wrench for inserting or removing the bushing.

The upper bushing 7 is provided wlth a passage 13, which is in turn fitted with a replaceable sleeve 14. It is through this passage that the flow of fluid to the drill bit must pass. Positioned between the upper bushing 7 and the lower bushing 8 is a ball valve 15. This valve has a passage 16 therethrough, which is arranged to normally serve as a continuance of the passage through the upper bushing 7. This ball valve 15 is mounted on antifriction bearings 17, which are positioned in grooves or openings 18 in the bushings l7 and 8. These openings 18 are preferably annular in form so that a series of ball bearings or roller bearings ma be positioned ineach groove so that the all valve 15 will move with a minimum of friction. In order to maintain the bearings in operative condition, a acking ring 20 is provided in each

ofathe ushings

7 and 8 adjacent the center thereof, and arranged to form a seal about the passage. and to contact the ball valve. A similar packing ring 20 is provided in the lower bushing 8. In assembling the device, one of the bushings-may be placed in position and the ball valve seated therein. The device can then be inverted and the remaining bushing placed in locking position so that the ball valve 15 maybe maintained in position such as shown in Figure 1. The lower bushing 8 is provided with a cut-away area (21, which is arranged to permit passage of the weighted portion 22 of the ball valve. This weight is connected by means of the stem 23 to the ball valve, and is provided in order that the valve will remain in the position shown in Figure 1, with the passages 16 and 13Cin alignment when the tool joint is in a vertical position. However, when the tool joint is inclined the weight 22 will-seek a vertical position due to the force of gravity and will tend to tilt theball 15 so-that the passage 16 is no longer in alignment with the passage 13. In this manner `the flow of Huid through the drill stem is either-restricted or completely cut olf, depending upon the degree of the inclination of the tool joint with respect to Ithe vertical. The cut-away shoulder in the bushing 8 allows of a tilting movement of l the ball valve 15 and the weight 22 so that it may assume a maximum inclination with respect to the tool joint, such as shown in,

the dotted line position in Figure 1.

It is intended that the ball valve 15, or other valve member used in practising the invention, may be mounted in any manner other than that shown in Figure 1, so lon as'the essence. of the invention is practise and this consists of restricting the flow` of fluid through to the drill bit directly in proportion to the degree of inclination of the drill bit.

When the drill bit is provided with a device such as herein described, it seems readily apparent that so long as the bit is penetrating the formation in a'vertical direction, such as well `bore 30 of Figure 3, the valve 15 will remain in open position due to the force of gravity because of the Weight 5.

cHowever, when the drill bit strikes some obstruction or is otherwise caused to deviate from vthe vertical its deviation will be quickly apparent to the driller because the force of gravity will cause the weight to maintain the passage 16 through the valve in a vertical position, and if the inclination is of a suiiicient amount to cause the passage 16 toy move out of alignment with the passage 13 it is then apparent that the ilow of fluid through vthe passage 13 will be restricted. Its restriction will increase the pressure required to cause circulation and the driller 4will instantly notice that the slush pump is laboring to maintain the circulation, and when he knowsthat this invention/has been Aincorporated in the tool joint, he is then aware that his drill bit has deviated from the vertical to a sufficient angle that the circulation is being restricted. -He can then withdraw the drill bit and plug back the short distance 31 of the hole which has deviated from the vertical and then continue his drilling irra vertical direction.

With some types of modern equipment high speed rotation of the drill bit is possible. When this occurs the valve may be constructed without anti-friction bearlngs. It is also ossible that when high speed rotation of t e drill bit occurs that the weight 22 when once moved oif center by inclination of the bit will then, due to centrifugal force, instantly move over to the maximum position such as shown in the dotted line position of Fig. 1.

Thus, in ractising the invention, the driller is advised when his bit has inclined from the vertical but a few degrees, and can instantly remedy the diiiiculty; whereas, with the present practise the bit deviates, and', in many instances, several hundred feet of hole are drilled before the operator is advised that his well is crooked. It is then necessary to plug back this several hundred feet by filling the hole with cement, and he can then attempt to drill a vertical hole.

The 00st of this plugging back operation is 130 quite expensive and delays the drilling of the Well. When the present invention is incorporated in the drill collar or tool joint ad]a cent the bit, the operator will be instantly advised of any deviation, and can then make his correction before any considerable crookedhole has been drilled.

It is contemplated that in the future development of the invention that various alterations and modifications may be resorted to, and that the structure shown herein and described is for purposes of illustration only, as the invention contemplates broadly the idea of indicating to the operator the deviation of his bit by .restricting or cutting oil the flow of fluid through the drill stem.

What we claim is: I

1. In combination with a drill stem coupling, a valve seat having a passage therethrough, a valve for said seat having a passage therethrough which is adapted to be normally in alignment with said valve seat assage, a depending weight on said valve aving a passage therethrough, said three passages being adapted for alignment when said coupling is disposed in a vertical position, and anti-friction bearings supporting said valve whereby said weight will cause movement of said valve and closing of said passae when said coupling is inclined.

2. gravity operated cut-olli` valve for drill stems to close off the passage of fluid when said stem is inclined beyond a predetermined degree, includingr a seat construction, a ball valve disposed in said seat for swiveling movement, a weight connected to said ball valve and depending therefrom, a passage throughsaid seat and a passage through said ball and weight which passa es are adapted to be aligned but which willgbe moved out of alignment by swinging of said weight to swivel said valve.

- 3. A gravity operated cut-oil' valve forv drill stems to close off the passage of fluid when said stem is inclined beyond a predetermined degree, including a seat construction, a ball valve disposed in said seat for swiveling movement, a weight connected to said ball valve and depending therefrom, a passage through said seat and a passage throu h said ball and weight which passages are adapted to be -aligned but which will be moved out of alignment by swinging of said weight to swivel said valve, and a sealing ring between said valve and seat about said passage.

In testimony whereof, we hereunto ax our signatures this 22nd day of August,

EDGAR C. JOHNSTON.

JOHN F. FOWLER, JR.