US1893693A - Rotary underreamer - Google Patents

Description

Jan. 10, 1933. 0 1,893,693

ROTARY UNDERREAMER I Filed Jan. 24. 1931 2 Sheets-Sheet l Inventor Patented Jan. 10, 1933 UNITED STATES PATENT OFFICE mo FRANK A101, 63F EUWATHGTON PARK, CALIFORNIA, ASSIGNOB T0 JOHN GRANT, 0F 10S ANGELES, CALIFORNIA EGTBLRZ UNDERBEAME'R Application filed January 24, 1931. Serial No. 510,988.

This invention has relation to underreamers, particularly underreamers of the rotary type for use in deep wells; and a general object of the invention is to provide a hydraulically actuated reamer of simple and efiective form.-

A further object is to provide a reamer which, when actuated to expanded position by hydraulic pressure, is locked and. held in that expanded position by arrangements inde endent of hydraulic actuation; so that failure or cessation of the hydraulic pressure does not in itself cause contraction of the reamer. And a further object is to provide, in such a reamer as is here contemplated, a suitable arrangement whereby the cutters ma be effectively contracted.

hese and other objects of the invention are embodied in the underreamer herewith illustrated and hereinafter described as typical and illustrative of the invention: in such a. typical embodiment 1 have utilized the swinging type of cutter-cutters which swing outwardly upon vertical axes on the reamer body. Such cutters, when swung outwardly to a certain amount of expansion will engage the walls of the hole in such a manner that reaming action of the reamer will carry the cutters to their fully expanded positions and will thereafter hold them in expanded position independently of any other expansive force. Such cutters may be contracted either by rotating the tool reversely or by pulling them up into contact with the casing or casing shoe, the heads of the cutters being provided with suitable surfaces to cause contracting swinging upon engagement with the casing.

Preferably utilizing cutters of such a type,

my invention provides a simple form of hy-- draulic expansion mechanism in a form typified by push rods which extend diagonally downwardly and outwardly to bear upon the cutters and which have, at their inner ends, suitable arrangement for taking hydraulic pressure in the central circulating passage of the tool. In the present instance I have shown a member in the form of a ball resting upon the upper inner ends of the push rods and, when the push rods are in and up,

sion of the cutters.

In the drawings,

Figure 1 is a central longitudinal section showlng my reamer in contracted osition; Fig. 2 is a similar view showing t e parts in expanded position;

Fig. 3 is a section on line 33 of Fig. 1; Fig. 4 is a section on line 4-4 of Fig. 2; Fig. 5 is a section on line 55 of Fig. 2; Fig. 6 is a section on line 6-6 of Fig. 2. A suitable body for the reamer is shown at 10, the body being provided with the longitudinal circulation passage 11 common to such tools. Near the upper end this circulation passage is enlarged as at 12 to form an enlarged chamber; and at the upper end of this chamber is located a bushing 13 having an orifice 14 and a ball seat 15. Orifice 14 forms part of the circulation passage and the seat 15 forms a seat for ball 16. Bushing 13 ma conveniently be located directly under t e screwthreaded ta r pin 17 which forms one member of the oint attaching the reamer body to drill stem 18.

In the form of reamer here illustrated the swinging cutters are shown as being made up of upper and lower heads 20 and 21 and roller cutters 22 mounted on cutter pins 23 extending between the two heads. These composite cutters may be taken as typical of any other type of cutter make-up. Each cutter, considered as a whole, is mounted on upper and lower vertical pivot pins 24 and 25 which pivot pins are mounted in the body above and below the body recesses 26 into which the cutters swing when contracted.

The push rods 30 extend downwardly and outwardly from chamber 12, through openings 31, into the body recesses 26; and, at their lower ends, engage and bear upon the upper cutter heads 20. These push rods are preferably provided with heads 32 at their inner ends, and the ball 16 rests upon these heads. Springs 34 may be provided under ward swinging of pivots24 from the the push rod heads if desired for the urthen the cutters may be contracted either by pose of returning the push rods and b 16 rotating the tool left-handedly or by pulling to the position of Figure 1 without the inform that function.

With reference to Figures 1 and 3, showing the parts in contracted position, .it will be seen that the upper heads ave recesses in which the lower outer ends of the push rods bear. These recesses are so shaped that the ends of the push rods bear against the heads at points somewhat ofi direct alinement with the centers of cutter pivots 24 so that outward longitudinal movement of the push rods will swing the cutters around their position shown in Figure 3 toward such a position as shown in igure 4.

In the normal position of the parts ball 16 closes or substantiall closes passage 14 by seating or substantially seatin on seat 15. Hydraulic pressure ap lied to t e circulation passage 11a causes t e ball to be forced downwardly and thereby forces the push rods down and out to such positions as shown in Figures 2 and 4. The openings 31 through which the push rods pass are made somewhat tapering, or large enough that the push rods may move lon 'tudinally outwardly, and their outer enfs follow the cutter heads, without any of the parts binding.

When theputters have been swung outwardly somewhat towards such a position as shown in Fig. 4, then the roller cutters 22 engage the side of the hole. Upon rotation of the-reamer body in the direction indicated bit; the arrow in Fig. 4, this wall contact of t e cutters drags the cutters further around in the expanding direction indicated by the d arrows, swinging about their swinging pivots 24. The cutters thus will be swung further around to such a position as shown in Fig. 4, wherein the points of contact with the wall are well outside the swinging centers 24; and in that position the cutters will be held expanded without any further pushing action from hydraulic actuation. It is not 'neces sary that the cutters swing outwardly and around far enough that the roller centers are exactly radially out from swinging centers 24, in order to accomplish the action last explained; the position of the rollers substantially outward from swinging centers 24, or somewhere near the position radially outward from those swinging cutters will suflice. Thus, the cutters may swing outwardly to expanded positions, near, or to, or beyond the radial position, as is desired.

The cutters will remain in their expanded positions until desired to be contracted,'regardless of whether the hydraulic pressure continues. When it is desired. to contract the cutters; hydraulic pressure is discontinned, allowing the ball and push rods to move back to their positions of Figure 1, and

the cutters having to perit up into the casing. It .is preferable to contract by casing contact; and for this purpose upper heads 20 are provided with diagonal outer surfaces 50 (see Figures 1, 2, 3 and 4 which surfaces engage w1th the lower end 0 the casing or casing shoe and, by their diagonal reaction, push the cutters inward- .ly as they are drawn upwardly against the casing.

' I claim:

1. In an expansive reamer, a body havin a fluid circulation passage, cutters mounte on the body on vertical swinging axes and adapted to'swing from an inner contracted position outwardly and circumferentially about the body to outer expanded positions wherein the outermost cutting element of each cutter is outside the swinging axis, so that engagement of the cutters with the wall of the hole keeps and holds the cutters in expanded position; and hydraulically actuated means to move the cutters from their contracted positions toward their expanded positions, said last mentioned means embodying cutter moving members impelled by fluid pressure in the fluid circulation passage of the body.

2. In an expansive reamer, a body having a fluid circulation passage therein, cutters mounted in the exterior parts of the bod and constrained to lateral movement wit reference thereto, push rods engaging the cutters and extending diagonally upwardly and inwardly into the movable member in the y, and a vertically boddy, upper inner ends of the re s,

engaging the and movable ownwardly under action of fluid pressure in the fluid passage In witness that I claim the foregoing I have hereunto subscribed my name this 9thday of Dec, 1930.

MlLLIO FRANK ALOI.

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