US2069482A - Well reamer - Google Patents

Description

Feb. 2, 1937. EAY 2,069,482

'WELL REAMER Filed April 1a, 1935 F&.-. 1%.2.

2 Sheets-Sheet l I :4 g /8 I l I H /4 1 H I 44 jimwrag Jay: Z Jana? Patented Feb. 2, 1937 UNITED STATES PATENT OFFICE WELL REAMER This invention relates to improvements in tools for drilling wells and more particularly to tools which have water-jets for use in connection therewith for the purpose of washing the walls of the bore or of locally enlarging the well bore at a desired place or places.

Wells, particularly for water supply are drilled through varied strata and into water bearing sand. A well casing is provided which extends through these varied strata and has at its lower end a strainer, which strainer is secured to, and projects below, the lower end of the casing, into if not entirely through, the sand strata. Water flows through this strainer from the sand, and the openings in the strainer must be large enough to allow the water flow yet fine enough to restrain the sand. Even so the openings are rapidly enlarged and the strainer must eventually be replaced or the well abandoned.

As one way of overcoming these difficulties, a bore much larger than the strainer used has been made and the space around the strainer has been filled with gravel. In such case reliance is placed in the gravel to restrain the sand and the openings in the strainer need only be small enough to prevent the finer gravel entering. Such gravel type of wells have not only largely increased the strainer life but have also eiiected tremendous increases in well capacities; but it has been necessary to make at extra cost, and ordinarily to case at still greater cost, a bore from the surface of the ground downward which approximated the desired diameter of the gravel section. But even in such case it has been found that the bit plasters up the well of the bore in the sand and largely reduces the well output,

In my previous application for patent, Serial No. 731,654, a well reamer has been shown, the purpose of which was to cut, and control the size of, a larger bore than that of the well, this larger bore being thereby formed of a controlled size which permitted a definite amount of gravel being placed around the strainer to accomplish the purpose hereinbefore set out. In such case the bore and easing through the overlying strata had only to be sufficiently larger than the strainer and the well pipe to allow the feeding in and placing of the gravel around the strainer after the latter was in place.

In my previously described application, the manner in which the reamer was enlarged and the manner in which water was fed to the reamer bit and to a pilot bit therebelow has been set out.

It has been found however, that while a reamer; of the type there set out very satisfactorily ac- Memphis, Tenn.

1935, Serial N0. 16,978

complishes an enlarged opening of controlled size, that there is a tendency here also for the outer end of the blades of the reamer to plaster the wall of the enlarged opening with fine silt or mud which respectively are found in the sand strata, and intermediate clay strata, such strata of course varying and being hidden and largely unknown and undetermined. The present invention contemplates the addition to a well boring bit or to an expandible reamer type of tool of means for washing the wall of the opening as it is being made whereby mud may be definitely either prevented from being plastered on the sand wall or be washed off after forming, or the opening in the sand be enlarged over the size of the opening through the clay or other impervious strata.

It has been stated in myprevious application that it is necessary that all of the water be delivered through the pilot bit, and it is still found necessary or at least advisable to deliver through the pilot bit a sufficient supply of Water to prevent the pilot bit choking and to cause the removal of the sand and gravel loosened by such bit and/or the reamer blades.

It is found however, that this function may be retained and water be delivered by increase of pressure laterally from the drilling bit or through the reamer means without diminishing the supply sent tothe pilot bit.

The principal object of the present invention. is to provide in well drill means for accomplishing a flow of water beyond the laterally outer surfaces of the drill or reamer means.

The means by which the foregoing and other objects are acomplished and the manner of their acomplishment will readily be understood from the following specification on reference to the accompanying drawings, in which,--

Fig. 1 is a vertical section to the center line of a drill stem and head and. at right angles to reamer blades carried by the head, showing the blades in closed or non-operative position, and showing the means by which flow of water to the pilot bit and to the reamer blade ends is accomplished.

Fig. 2 is a side elevation taken at right angles to Fig. 1 with the reamer blades extended into cutting position.

Fig. 3 is a fragmentary sectional elevation corresponding to Fig. 2 showing a modified form of connection from the feed supply lines to the blades, the blades being in open position.

Fig. 4 is a corresponding fragmentary sectional elevation showing the same connection with the blades in closed position.

Fig. 5 is a section taken as on the line VV of Fig. 1.

Fig. 6 is a fragmentary sectional elevation showing an additional method of forming the water channel or passageway in the bit and Fig. '7 a transverse section on the line VIIV'II of Fig. 6.

Fig. 8 is a sectional elevation of the device showing a drill bit provided with lateral passageway, and

Fig. 9 a complementary elevation taken at right angles to the view shown in Fig. 8.

Fig. 10 is an elevation of a modified form of the bit shown in Fig. 8, shown partly in cross section.

In such case and ordinarily in most cases, the reamer type of the device is advisable either as a follow up, or directly the sand strata is reached.

Referring now to the drawings in which the various parts are indicated by numerals, the reamer form of the tool comprises essentially a head l4 which is screwed on to a drill pipe 15 which extends to the surface of the ground. The head I4 is transversely slotted at I6 to provide a pocket in which reamer blades I? are housed. In Figs. 1, 4 and 5, these blades are shown in retracted position and in Figs. 2, 3 and 6, in open position. Adjacent the upper end of the pocket I6, is a pivot pin E8 on which the blades ll are pivoted, the holes for the pivot pin in each blade being adjacent an end thereof. Extending upward from the slot I6, is a restricted bore I!) in which a piston rod 20 is slidably mounted. Above the bore E9, the head is provided with an enlarged cylindrical bore or cylinder 2| in which is disposed a suitable piston 22.

Disposed between the piston and abutting the underside thereof is a compression spring 30 which acts to hold the piston and the piston rod attached thereto in raised position. Pivotally connected to the blade I? as by pins 3| are links 32, one link being connected to each of the blades. The opposite ends of these links are both connected by a joint pin 33 to the lower end of the piston rod 29, the relation of the linkage, the piston rod and the reamer blades being such that when the piston is in raised position the reamer blades are retracted into closed position "A in the head, and when the piston is fully depressed the reamer blades are extended substantially at right angles to the head. Restraining means such as are shown in my previous application may be provided to assist in holding the blades in extended position, but such means not being germane to the present invention are not here shown or described.

The lower end of the head 14 is adapted to carry a drill bit 40 which is provided with a passageway or passageways 42, which lead from its open end downward adjacent its point. The cylinder 2! is provided with two openings 43 and 44 both of which lead into a passageway 45 that extends downward toward the head [4, and is connected thereinto above the end of the drill bit, thereby establishing a passageway from the hollow drill stem to the lower end of the bit. The opening 43 into the passageway 45 is above the upper end of the piston 22 and is held to the minimum size which will serve the drill point 40. This hole may do this and yet be so small that enough pressure may still be put on the piston to force it down and expand the blades into reaming position. The lower opening 44 is immediately above the piston when the latter is in its lowest position, and is of sufficient size to provide flushing water for the reaming blades. The passageway 45 is continuous from these openings to the bit, so that all water or other flushing fluid must be discharged through the bit, thereby definitely flushing the bit both when the reamer blades are operative or inoperative. This being in accordance with my previous application referred to.

An additional opening 59 is provided in the wall of the cylinder 2i, this opening preferably being substantially at the level of the opening 44, in order that opening pressure may be built up on the piston 22 as before to open the reamer blades. From the opening 55 a passageway 5| leads downward along the head and to the reamer blades. In Figs. 1 and 2 the passageway 51 is shown as a tube leading into the end of the pin !8, the pin being provided with a central bore 52. The blades H are each provided with a passageway 53, 54, which passageways lead from the hole for the pivot pin l8 to the end of the blades, preferably adjacent the upper edge of the blades when the latter are in extended or cutting position. The pin i8 is also provided with holes 55, 56 on opposite sides thereof with which the passageways 53, 54 of the blades respectively register when the blades are extended. There is thus established a passageway from the drill pipe l5 through the cylinder 2| above the piston 22 to the outer ends of the reamer blades, through which a stream of water may be discharged against the wall 5'! of the enlarged opening cut by the blades. In Figs. 6 and 7 these passageways are shown as grooves 53A, 54A, channeled in the blades and covered by plates 53B, 543, respectively, preferably welded on.

In Figs. 3 and 4 the passageway or tube 5! leading from the cylinder 2! is shown joined by two flexible connectors 58 and 59, to passageways 53C in the blades, which passageways as before lead through the blades to the outer ends thereof. In these views Fig. 3 shows substantially the positioning of the flexible connectors 58 and 59 when the blades are open or in cutting position, a

and Fig. 4 shows the positioning of these connectors when the blades are in closed position. Preferably the passageways 53, 54-, etc. are provided at their discharge end each with a nozzle 60.

In Figs. 8 and 9 a modified form of bit 40A is shown secured as by a coupling 6| to the drill pipe 15. This bit has in addition to the passageways 42A leading adjacent the bit point, oppositely disposed passageways 62, leading laterally to opposite sides thereof, and each preferably provided with a nozzle outlet 53. In Fig. 10 the bit 403 is cut away as at 64 to move the nozzles 63A away from the side edges of the bit, and minimize clogging of the nozzles when not under heavy or cutting discharge pressures.

In using the form of the device shown in Figs. 8, 9 and/or 10, drilling is done using only sufiicient water pressure through the pipe I5 to flush and keep the bit 42A clean, such pressure being usually insufficient to cause objectionable cutting on the walls of the bore, through the clay or other harder strata.

When flushing discharge, indicates that the sand strata has been reached or this is otherwise known, pressure on the water in the pipe I5, is increased and a lateral discharge is established through the nozzles 63, cutting away the sand and locally enlarging the bore at such point. Such action in some cases supplying sumcient opening or cavity for a gravel wall around the strainer.

In most cases however the enlargement is so uneven as to cause trouble and in any event is an unknown quantity owing to uneven hardness of portions of the sand. Also after sand is found strata or lenses are encountered which are not cut away and enlarged by the water jets, these often interferring seriously with placing of gravel therebelow, so that particularly in deep and expensive wells having great depth of sand, mechanical enlargement is advantageous.

In using the reamer type of the device, the assembly with reaming blades held closed as by the action of the spring 30, is lowered into the well. If desired drilling is done with the bit flushing water being delivered through the opening 43 and passageway 45 to the drill bit. When it is desired to expand the reamer blades into operative position much heavier pressure is exerted upon the fluid in the drill stem and the piston 2! is forced downward moving the blades outward into cutting position. When so opened water flows through the tube 45 to the drill bit providing flushing water for removing the cuttings. At the same time water flows through the pipe 5! and discharges through the ends of the blades against the wall 5? of the enlarged opening being cut by the blades, further enlarging the opening if the sand is very loose, but in any event, largely removing mud or other material plastered on the wall by the cutting action of the blades.

Obviously the tube 5| should be of equal or greater size than the nozzle ends of both the passageways 53, 54, in order that effective discharge pressure may be maintained.

It will be understood that while I have showed two methods of forming the passageway through the blades, that these passageways might otherwise be formed so long as they serve to connect the pipes M to the ends of the blades.

Obviously also the openings in the ends of the blades might as readily be at any point from top to bottom thereof as that shown in the upper corner. or bottom surface of the blade adjacent the end. Also the blade corners may be cut away as in the bit shown in Fig. 10.

It will be further understood that while I have shown in the reamer type, one having blades conforming in general design to those shown in my previous application and similarly actuated, that the present device will function in other forms of reamers and that it is not my intention to limit myself in the present improvement to a reamer of such type, or one having blades, or to a reamer having flushing apparatus as there shown.

What I claim is:

1. In a well boring tool having expandible reamer blades, means for accomplishing lateral fiow of liquid from the peripherally outer ends of said blades.

2. In a well boring tool having reamer blades Or the discharge might be from a top and means for extending and retracting said blades, means for furnishing flow of liquid laterally from the peripheral extremities of said blades when in laterally extended position.

3. In a well boring tool having reamer means, means for retracting and means for extending said reamer means, means for forcing a supply of liquid laterally from the peripheral extremities of said reamer means when said means are laterally extended and means actuated by said retracting means for cutting off flow to said reamer means.

4. In a well reamer, a pair of pivotally mounted reamer blades, means for extending said blades to lateral positions, the upper portion of each said blade when in lateral position lying laterally inward from a portion therebelow, said blades having each a passageway therethrough terminating at the lateral end of the blade, and in said upper portion, and means for furnishing a supply of liquid to said passageways.

5. In a well reamer including a drill pipe, a pair of reamer blades pivotally carried by said pipe and adapted to be laterally extended and means for extending and retracting said blades, passageways carried by said blades and discharging adjacent the lateral and upper extremities thereof, when said blades are in extended position; and means for establishing passageways connecting said drill pipe and said blade passageways.

6. In a well reamer including a drill pipe, a head carried thereby, a pair of reamer blades pivotally mounted in said head and adapted to be laterally extended and means for extending and retracting said blades, passageways carried by said blades and discharging adjacent the laterally upper extremities thereof, when said blades are in extended position, and means for establishing passageways connecting said drill pipe and said blade passageways, said blade extending means rendering said passageways inoperative when said blades are retracted.

7. In a well reamer including a drill pipe, a head carried thereby, a pair of reamer blades pivotally mounted in said head and adapted to be laterally extended and means for extending and retracting said blades, passageways carried by said blades and discharging adjacent the upper lateral extremities of said blades when said blades are laterally extended, and means for establishing passageways connecting said drill pipe and said blade passageways.

8. In a well reamer including a drill pipe, blades adapted to be laterally extended carried by said pipe, and means for extending said blades, said blades each having a passageway therethrough which in laterally extended position of said blades discharges from the peripherally outer end of said blade, of means connecting the inner ends of said passageways with the interior of said pipe, said blade extending means rendering said connecting means ineffective when said blades are retracted.

JAMES I. SEAY.

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