US2704655A - stokes - Google Patents

Description

March 22, 1955 J. c.,sToKEs CORE DRILL 2 Sheets-Sheet l Filed May 31, 1952 W MMM M 96 7, 5 my?? f, N Z/////., w\\ 210 y.. l z` 2 M y, H 26 l .2 I|| ill.; |||2, @TIN Z H U Zn...

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Phu/uri TORNEY March 22, 1955 Filed May 31, 1952 INVENTOR.

BY n l ATTORNEYS United States Patent O CORE DRILL John C. Stokes, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Application May 31, 1952, Serial No. 290,971

Claims. (Cl. Z55- 72) This invention relates to deep well core drills. Conventional deep well core drills comprise a drill stem having a bit secured to the lower end thereof. The bit has a central opening therein through which the core may pass, and a core barrel is mounted within the stem above the bit to receive and retain the core.

This invention has for one of its general objects the provision of a core drill having new and improved means whereby the upper end of the core barrel will remain closed as the core drill is lowered into the well, so that detritus will not become packed therein, and at the same time drilling uid will be permitted to flow upwardly in the drill stem about the exterior of the barrel', whereby, when the core drill has been lowered to a point near the bottom of the hole, drilling uid may be pumped downwardly through the barrel to wash it out; whereby during coring operations drilling iluid which would otherwise be trapped within the barrel is permitted to escape therefrom but drilling fluid pumped downwardly in the drill stem is prevented from entering the barrel; and whereby when the core drill is removed from the well, drilling uid is prevented from entering the barrel.

One of the specic objects of the invention is to provide a new and improved valve means for core barrels.

Other objects will hereinafter appear.

The preferred embodiment of the invention is illustrated by the accompanying drawings in which Fig. l is a partly sectional elevation of the lower portion of a core drill Fig. 2 is a fragmentary sectional elevation illustrating my new and improved valve means, the parts of the valve means being in the positions they occupy during the lowering of the core drill into the well.

4 Figc.1 3 is a horizontal section on the line 3-3 of Fig.

Fig. 4 is a view corresponding to Fig. 2 showing the positions of the parts of the valve means during coring operations and when the core drill is being removed from the wells.

Referring to Fig. l of the drawings, a drill stem is indicated at 1, an outer barrel at 1a, and a core bit at 2. The bit 2 may be provided with suitable roller cutters or the like 3, and it has a central opening 4 through which the core may pass into the core barrel 5. At the lower end of the core barrel a suitable core catcher 6 may be provided to retain the core in the barrel 5. The parts thus described are conventional parts.

Referring now to the new and improved construction illustrated in detail by Figs. 2, 3 and 4 and constituting one embodiment of my invention, the upper end of the core barrel 5 may have threaded therein as indicated at 7 a valve sub 8 provided with external longitudinal grooves 9 to permit the passage of drilling uid thereby. Threaded in the upper end of the sub 8 as indicated at 10 is a member 11 provided with longitudinal openings 12 to permit the passage of drilling fluid therethrough. The upper end of the member 11 may be provided with a reduced extension 14 to t within the coupling member 15 of the drill stem 1, and on the shoulder 16 provided by the reduction of the end 14 of the member 11 may be a suitable annular packing 17.

The member 8 has an opening in its lower end in which is disposed a valve seat 18 and a housing 19. The numeral 20 indicates a valve having an upper end 21 vertically slidable within the seat 18 and having in its periphery a suitable sealing ring 22. The extremity of the end 21 is reduced and projects upwardly as indicated Patented Mar. 22, 1955 at 23. The valve 20 is also vertically slidable in the housing 19 and is provided with longitudinal grooves 24 to permit the passage of drilling fluid thereby when the valve is in the position shown by Fig. 4. The valve 20 is provided with a downwardly opening central recess 25 and in this recess is a coiled spring 26, the ends 27 and 28 of which extend through openings in the depending legs 29 of the valve. When the valve is moved by the drilling fluid under pressure from the position shown by Fig. 2 to the position shown by Fig. 4, the ends 27 and 28 of the coil spring 26 are forced inwardly by the tapered wall of the opening 30 in the bottom of the housing 19 to permit full downward movement of the valve 20 until the tapered lower portions 31 of the depending extensions 29 are resting upon the tapered surface 30 of the housing 19. As soon as the ends 27 and 28 clear the lower end of the housing 19, the spring moves these ends outwardly to prevent the upward movement of the valve 20 from position shown by Fig. 4 to its original position shown by Fig. 2.

The numeral 32 indicates a ball which, when dropped into the drill stem 1, will fall and may be pumped downwardly until it strikes the upwardly projecting extension 23 of the valve 20 to move the valve 20 from the position shown by Fig. 2 to the position shown by Fig. 4 and to then rest upon the seat 18 to prevent further passage of drilling fluid downwardly through the seat 18 but to permit passage of drilling uid upwardly through the seat 18.

In the use of the core drill, the parts just described will 'ice function as follows:

In the preferred embodiment, the core barrel 5 is disposed in the outer barrel 1a which is attached to the drill stem coupling member 15. With the valve 20 in the position shown in Fig. 2, the drill stem 1, with the coring apparatus thus attached, is then lowered into the well. As the drill stem descends into the drilling uid already standing in the well, the valve 20 prevents the movement of the drilling uid and detritus upwardly through the core barrel thereby reducing the possibility of jamming the core barrel assembly or of packing the core barrel with cuttings or detritus already in the well bore. As the drill stem descends, the drilling fluid standing in the well passes upwardly through the core bit 2; through the annular passage 33; through the longitudinal grooves 9; the openings 12; and thence upwardly through the bore 34 of the coupling 15 of the drill stem 1. If the drilling fluid, standing in the well were not permitted to enter the drill stem, as it is being lowered into the wall, the buoyancy effect of the drilling uid would tend to float the entire drill stem and a corresponding amount of drilling fluid would be displaced from the well. As the drill stem 1 is withdrawn from the well, the drilling uid in the drill stem may pass downwardly through the drill stern; through the bore 34; through the openings 12;through the grooves 9; and through the annular passage 33, returning to the well through the core bit 2. This arrangement prevents the retention of drilling uid in the drill stem and prevents pulling a wet string, accordingly, the drilling uid level in the wall is not disturbed substantially.

After the drill stem has been lowered into position at a point near the bottom of the well (Fig. l), conventional mud pumps at the surface of the earth force drilling fluid downwardly through the drill stem 1. The resulting uid pressure causes the valve 20 to move downwardly into the position shown in Fig. 4, thereby permitting the circulation'y of some of the drilling fluid through the valve seat 18; through the longitudinal grooves 24 of the valve 20; and thence downwardly through the bore 35 of the core barrel 5 to wash cuttings and detritus therefrom. The ball 32 is then dropped into the drill stem 1 and comes to rest on the valve seat 18 as shown in Fig. 4.

The drill stem 1 is now rotated and lowered in a conventional manner causing the core bit 2 to penetrate the formation at the bottom of the well (Fig. l). The core bit 2 has aA central opening 4 through which the uncut central portion of the formation, or core, may pass and enter into the core barrel 5. When the desired length of core has been cut, the drill stem rotation is suspended and the mud pumps are stopped causing the drilling fluid circulation to cease. The drill stem 1 is now lifted causing the core catcher 6 to grip the core in a conventional manner to break the core from the bottom of the well and retain it in the core barrel 5. The drill stem may then be lifted to the surface of the earth and the core may then be removed from the core barrel.

As shown in Fig. 4, when the valve 20 has been moved downwardly by the drilling fluid pressure to its fully opened position, the spring ends 27 and 28 are urged by the coiled spring 26 to project outwardly beyond legs 29 of the valve to extend below the lower surface of the valve housing 19. The spring ends prevent the closing of the valve 20 after it has been fully opened since the spring ends 27 and 28 engage the lower surface of the housing 19 upon upward movement of the valve. The ball 32 resting on the seat 18 prevents the circulation of drilling fluid downwardly through the valve and core barrel and acts as a check valve permitting the passage of uid upwardly from the core barrel through grooves 24 of the valve 20 as the core enters the core barrel 5 and displaces the fluid in the core barrel. The ball 32 prevents the drilling fluid from entering the core barrel 5 during the coring operation and also prevents the washing of the core by the drilling uid as the drill stem is being withdrawn from the well. The weight of the ball 32 may serve to open and hold the valve 20 in the position shown in Fig. 4 by engaging the reduced end 23 of the valve 20 if the drilling fluid pressure has not caused the valve 20 to open fully.

The invention is not limited to the preferred embodiments herein disclosed. Various changes within the scope of the following claims will be apparent to those familiar with the art.

I claim:

1. A coring apparatus comprising an outer barrel having a core bit secured to the lower end thereof; a core barrel within and spaced concentrically from said outer barrel to permit the passage of fluid therebetween; said core barrel adapted to receive and retain a core; a valve sub secured to the upper end of said core barrel, said valve sub having an opening through the lower portion thereof; a valve seat and a valve housing disposed in said opening; a valve slidably disposed within said valve seat and said valve housing; said valve having a sealing ring in its periphery and adapted to move downwardly by iluid pressure acting thereon; a reduced central extension on the upper end of said valve; radially disposed grooves in the lower end of said valve to permit the passage of Huid thereby; said valve having a downwardly opening central recess; a coil spring in said recess; the ends of said coil spring extending through openings in the lower portion of said valve and adapted to move outwardly and project below the lower surface of said valve housing upon full downward movement of said valve to prevent subsequent upward movement thereof and a ball dropped into said coring apparatus to prevent the subsequent passage of fluid downwardly through said valve.

2. A well coring apparatus comprising an outer barrel having an annular bit secured to the lower end thereof; a core barrel within and spaced concentrically from said outer barrel to permit the passage of fluid therebetween; said core barrel adapted to receive and retain a core; a valve sub secured to the upper end of said core barrel, said valve sub having an opening through the lower portion thereof; a valve seat and a valve housing disposed in said opening; a valve slidably disposed within said valve seat and said valve housing; said valve having a sealing ring in its periphery; a reduced central extension on the upper end of said valve: radially disposed grooves in the lower end of said valve to permit the passage of iluid thereby; said valve having a downwardly opening central recess; a coil spring in said recess; the ends of said coil spring extending through openings in the lower portion of said valve and adapted to move outwardly and project below the lower surface of said valve housing upon full downward movement of said valve to prevent subsequent upward movement thereof; and a ball dropped into said coring apparatus to prevent the passage of fluid downwardly through said valve.

3. A coring apparatus comprising an outer barrel having a core bit secured to the lower end thereof; a core barrel within said outer barrel; said core barrel adapted to receive and retain a core; a valve sub secured to the upper end of said core barrel, said valve sub having an opening through the lower portion thereof; a valve seat and a valve housing disposed in said opening; a valve slidably disposed within said valve seat and said valve housing; said valve having a sealing ring in its periphery; a reduced central extension on the upper end of said valve; radially disposed grooves in the lower end of said valve to permit the passage of fluid thereby; said valve having a downwardly opening central recess; a coil spring in said recess; the ends of said coil spring extending through openings in the lower portion of said valve and adapted to move outwardly and project below the lower surface of said valve housing upon full downward movement of said valve to prevent subsequent upward movement thereof.

4. A well coring apparatus comprising an outer barrel having an annular bit secured to the lower end thereof; a core barrel within and spaced from said outer barrel to permit the passage of fluid therebetween; said core barrel adapted to receive and retain a core; a valve sub secured to the upper end of said core barrel, said valve sub having an opening through the lower portion thereof; a valve seat and a valve housing disposed in said opening; a valve slidably disposed within said valve seat and said valve housing; a reduced central extension on the upper end of said valve; radially disposed grooves in the lower end of said valve to permit the passage of fluid thereby; said valve having a downwardly opening central recess; a coil spring in said recess; the ends of said coil spring extending through openings in the lower portion of said valve and adapted to move outwardly and project below the lower surface of said valve housing upon full downward movement of said valve to prevent subsequent upward movement thereof.

5. In a coring apparatus, a core drill, a core barrel within said core drill to receive and retain a core, a valve housing secured to the upper end of said core barrel, a valve in said housing, said valve having a downwardly opening central recess; a coil spring in said recess; the ends of said coil spring extending through openings in the lower portion of said valve and adapted to move outwardly and project below the lower surface of said valve housing upon full downward movement of said valve to prevent subsequent upward movement thereof.

References Cited in the tile of this patent UNITED STATES PATENTS 1,903,232 Giesey Mar. 28, 1933 2,164,652 Holoss July 4, 1939 2,214,238 Stovall Sept. 10, 1940 2,596,832 Williams May 13, 1952

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