US1746694A - Underreamer - Google Patents

Description

Feb. 11, 1930. H. F. CLEM'ENT 1,746,694

UNDERREAMER Filed March 6, 1928 L l JIM Patented Feb. 11, 1930 vide and improved arrangement of supports or carrying blocks for the reaming bits or cuthaving UNITED STATES PATENT OFFICE HUBLEY F. CLEMENT, OF LONG BEACH, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, OF ONE-HALF T0 JOHN GRANT, OF LOS ANGELES, CALIFORNIA UNDEREEAMER Application filed March 6, 1928. Serial No. 259,415.

My invention relates to an underreamer that is particularly designed for use in deep wells for reaming or increasing the diameter of the well hole in order to' permit the casing to be lowered as the drilling proceeds, and the principal objects of my invention are to generally improve upon and simplify the con.- struction of the existing forms of underreamers, and to provide simple and efficient means whereby the reaming bits or cutters will automatically move into expanded or reaming positions as the reamer is lowered into position below the lower end of the eas- Further objects of my invention areto proters and to mount said blocks or carriers 1n the body of the reamer so that they will be positively guided during their movement from retracted to expanded'position and vice versa; further, to provide an underreamer ducts for the accommodation of the circulation of fluid during underreaming operations, and further, to provide simple and efiicient means whereby the reaming bits or cutters are expanded. or moved into reaming positions under the influence of an expensive coil s ring.

With the oregoing and other objects in view, my invention consistsin certain novel features of construction and arrangement of parts that will be hereinafter more fully describe'd'and claimed and-illustrated in the accompanying drawings in which:

'Fig. 1 is an elevational view of an underreamer of my improved construction,

Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1.

Fig. 3 is a horizontal section taken on the line 33 of Fig. 1.

Fig. 4 is a horizontal section taken on the line 4-4: of Fig. 2. i

Fig. 5 is an elevational view of the inner face of the .lower portion of one of the parts.

of the body of the underreamer.

Fig. 6 is a vertical section taken lengthwise thru the center of one of the bits or cutter carrying blocks.

Fig. 7 is an enlarged horizontal section taken on the line 7'--? of Fig. 6.

Fig. 8 is a horizontal section taken on the line 8-8 in Fig. 2. I

Referring by numerals to the accompanying drawings which illustrate a practical embodiment of my invention, 10 designates the body of the underreamer which is in the form of an elongated cylinder, and said body being formed in two parts that are identical insize, form and construction and the joint or division line 11 between the two parts being on a longitudinally disposed medial plane. The parts of the body of the under reamer are detachably connected in any suitable manner, preferably by means of bolts 11 that pass thru the upper and lower portions of the body on opposite sides of the axis thereof.

The upper portion of the body is slightly reduced in-diameter and this reduced porany desired shape, either the fishtail type as shown or an ordinary diamond point bit.

The inner portions of the two parts that form the body of the underreamer are cut away a short distance above the bit 13 to form a transversely disposed chamber or opening 14 that is substantially rectangular in form and which accommodates the blocks or carriers for the bits or cutters, and formed in the body 1Q immediately below this opening is a pocket 15 that is adapted to receive the lower portions of the bit carriers when the latter are moved downward to retract the bits or cutters. Formed in the inner faces of the two parts of the body 10, and leading downwardly from the pocket 15 to points on opposite sides of the upper portion of the bit 13 are fluid circulation ducts 16.

Formed in the side faces of the opening 14, adjacent to the. upper end thereof and within the pocket 15, are pairs of grooves 17 that are adapted to receive trunnions that project from the sides of the bit or cutter carrying blocks. The members of each pair of these grooves are inclined and they are arranged so that they diverge upwardly and the members of the two upper pairs of grooves have greater inclination or divergence than the members of the lower pairs (see Fig. 5). As a result of this particular arrangement or inclination bf the pair of grooves, the upper ends of the bit or cutter carrying blocks will have a greater degree of inward and outward movement than the lower ends of said blocks.

Arranged within the opening 14 is a pair of reamingbits or cutter carrying blocks, each of which comprises an inner plate 18 and outwardly projecting end lugs 19. The intermediate portion of each plate 18 is provided with a longitudinally disposed slot 20 which permits the passage of circulation liquid, and seated in the lugs 19 and the ends of a rod 21 upon which is loosely mounted a reaming bit or cutter 22, preferably of the type having longitudinally disposed ribs formed on its outer surface.

In some instances, it may be found desirable to form each bit or cutter in two or more parts.

Extending horizontally thru each lug 19 is a pin or rod 23, the ends of which project short distances beyond the side faces of the lugs, as illustrated in Fig. 7, and these projecting ends provide trunnions that occupy the corresponding grooves 17 in the body of the underreamer. In order to locate the rods 21 in the lugs 19, said rods 21 are provided with notches 24 that receive the pins 23 when the latter are seated in the lugs and thus the rods 21 are securely fastened to the lugs and their accidental displacement is effectually prevented.

The inner faces of the two parts of the body 10 of the underreamer above the openin 14 are recessed to provide a substantially cy indrical chamber 25, and extending lengthwise thru this chamber, is an axially disposed tube 26, the upper end of which communicates with an axially disposed circulation duct 27 that is formed in the upper end of the body, and the lower end of this tube is clamped between the parts of the body 10 immediately above the opening 14. In order to prevent this tube 26 from becoming unseated and dropping downwardly into the opening 14, the lower end of said tube or that portion that is clam ed between the parts of the underreamer ody, is tapered as designated by 28, and the seat that accommodates said tapered lower end is correspondingly tapered (see Figs. 2 and 5).

Arranged for sliding movement on the upper portion of the tube 26 is a ring shaped plate 29, and pivotally connected thereto on opposite sides are the upper ends of rods 30 which latter extend downwardly thru grooves 25" that are formed in the body 10 on opposite sides ofthe chamber 25, and the lower ends of these rods 30 are pivotally connected to the upper inner corners of blocks or cutters.

Surrounding tube 26, is an expansive coil spring 31, the upper end of which bears against the underside of the ring 29 and the lower end of said spring bears on a shoulder 32 that is formed within the body 10 just above the tapered seat 28 for the lower end of tube 26 (see Figs. 2 and 5).

Under normal conditions, the expansive power of spring 31 retains ring 29 at the upper end of its travel within the chamber 25 and when so positioned, the reaming bit or cutter carrying blocks are retained at their upper limit of movement, as illustrated in Fig. 2 and due to the engagement of the trunnions in the pairs of grooves 17 and due to the inclination or angularity of said grooves, the bit or cutter carrying blocks, when at the upper limit of their movement, are in expanded or projected positions.

When the underreamer is lowered into the well, the threaded upper end of the body of the reamer is connected to the lower end of the drill tube and the reaming bit blocks are moved downwardly in the opening 14 until they occupy their retracted positions, and the reamer is now inserted in the upper end of the casing and moved downwardly therethru, during which movement the reaming cutter bears against the inner face of the casing and due to the internal diameter of said casing, the cutters and the blocks carrying same are prevented from moving upwardly 1nto expanded positions.

When the underreamer reaches a point below the lower end of the casing, the expansive power of spring 31 will act to move ring 29 upwardly, thereby drawing the reaming bit carrying blocks upwardly until the upper ends of the blocks bear against the body of the underreamer above the opening 14 therein, and the trunnions in moving upwardly thru the inclined pairs of slots 17, will cause the blocks to move outwardly simultaneously with their upward movement, and due to the fact that the upper pairs of grooves 17 have greater inclination than the lower pairs, the upper portions of the blocks will be moved outwardly to a greater degree than the lower portion. Thus, when said blocks are in expanded or reaming position, they will occupy inclined positions as illustrated in Fig. 2.

As the underreamer is rotated, the bits or cutters 22 will engage and cut away the formation in the well hole below the lower end of the casing, thereby accomplishing the desired underreaming operation and enabling the casing to be lowered as the drilling proceeds.

Circulation of water to carry off the cuttings from the underreamer is made possible due to the provision of the duct 27, tube 26, opening 14, openings 20 in the inner walls of the reaming bit carrying blocks and the ducts the bit carrying 16 that lead downwardly to the sides of the bit 13 that depends from the lower end of the underreamer.

When the underreamer is withdrawn from the well hole, the upward movement of said underreamer will bring the upper ends of the blocks'into engagement with the shoe in the lower end of the casing, and further upward movement of the underreamer will force the blocks downwardly thru the opening 14 until the lower ends of said blocks occupy the pocket 15 and due to the angularity of the pairs of'grooves 17 in which the ends of the pins 23 travel, the blocks will be moved inwardly simultaneously with their downward movement, thereby permitting the blocks and the bits carried thereby to enter the casing and to be drawn upwardly therethru.

Thus, it will be seen that I have provided an underreamer that is relatively simple in construction, inexpensive of manufacture and in which the reaming bits or cutters occupy slightly inclined positions when in expanded or cutting position, and which arrangement is especially desirable due to the fact that the cutters act on the formation of angular line relative to the axis of the underreamer rather than on lines that are parallel with said axis.

It will be understood that minor changes in, the size, form and construction of the various parts of my improved underreamer may be made and substituted for those herein shown and described without departing from the spirit of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. In an underreamer, a cylindrical body providedwith an opening, and there being pairs of grooves formed in the body of the underreamer to the sides of said opening, the members of the upper pairs of grooves having greater inclination than the members of the lower pairs of grooves, cutter carrying blocks arranged within said opening, and trunnions projecting from said blocks into said grooves.

2. In an underreamer, a cylindrical body provided with an opening, and there being pairs of grooves formed in the body of the underreamer to the sides of said opening, the members of the upper pairs of grooves having greater inclination than the members of the lowerpairs of grooves, cutter carrying blocks arranged within said opening, trunnions projecting from said blocks into said grooves, and a spring for normally holding said blocks at their upper limit of movement. 4

3. In an underreamer, a cylindrical body provided with an opening, a pair of cutter carryingblocks arranged within said opening, pairs of grooves formed in the body of the underreamer to the sides of said opening, the members of each pair of grooves diverging upwardly, the members of the upper pairs of grooves having greater divergence than the members of the lower pairs of grooves, and trunmons projecting from the cutter carrying blocks into said grooves.

4. In an underreamer, a cylindrical body provided with an opening, a pair of blocks arranged for vertical and lateral movement within said opening, a rotary cutter carried by each block, and there being a circulation opening formed thru each block to the rear of the cutter carried thereby.

In testimony whereof I alfix my signature.

HURLEY F. CLEMENT.

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