US3420321A - Apparatus for drilling wells - Google Patents

Description

Filed Sept. 6, 1966 INVENTOR.

ATTORNEY;

United States Patent 16,043/ 66 US. Cl. 175-173 Int. Cl. E21b 21/00 3 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to an apparatus for drilling wells under circulation of drilling mud, including a string of hollow rods allowing passage of drilling mud therethrough, a tubular member having drilling tools connected at the lower end thereof and in telescoping relation with respect to said string, cable means connected with said tubular member and extending along said string beyond said well, driving means for reciprocating said tubular member in a direction parallel to said string and cooperating with said cable means, a rotary table for imparting intermittent angular movement to said drilling tools about the axis of said string, a pump for circulating the drilling mud and having its suction pipe connected with said string of hollow rods.

The present invention relates to an apparatus for drilling wells or holes in general in grounds of any nature and consistency.

It is known in the art of well drilling to support the walls of the well by means of colloidal drilling muds, such as mortar containing drilling muds.

The bore hole Or well is always kept full with drilling mud or mortar muds, so that a constant direct supporting action is exerted on the walls thereof.

The known systems for drilling, wells, holes, and the like use tools which, by exerting a cutting action on the ground, disintegrate the same and carry it up to the top of the bore hole or such tools have only the task of disintegrating the ground, while the ground thus disintegrated is carried to surface by drilling muds.

In practice, it has been found that such systems have numerous disadvantages as a consequence of the way the tools act on the ground.

Systems utilizing 'tOOls such as clamshell buckets, scrape buckets and the like, are generally very slow and encounter problems in cutting compact or immersed grounds, while when drilling muds are provided it is difficult to control the removal of waste or cuttings.

Summary of the invention An object of the present invention is to provide an apparatus adapted to allow a quick drilling of bore holes even and particularly in hard or compact ground, such as rocks.

Another object of the present invention is to provide an apparatus which will allow easy to drill wells of considerable depth.

A further object of the present invention is to provide an apparatus which will allow to obtain wells, holes, cuttings and the like having completely vertical side walls.

A still further object of the present invention is to provide an apparatus of low cost.

These and still other objects are attained by an apparatus for drilling wells under circulation of drilling mud, including a string of hollow rods allowing passage of drilling mud therethrough a tubular member having drilling tools connected at the lower end thereof and in telescoping relation with respect to said string, cable means connected with said tubular member and extending along said 3,420,321 Patented Jan. .7, 1969 string beyond said well, driving means for reciprocating said tubular member in a direction parallel to said string and cooperating with said cable means, a rotary table for imparting intermittent angular movement to said drilling tools about the axis of said string, a pump for circulating the drilling mud and having its suction pipe connected with said string of hollow rods and wherein the improvement comprises a sleeve member surrounding a length of said string and rigid and coaxial therewith, said sleeve member having an outer diameter less than the inner diameter of said tubular member, cooperating longitudinal guideway means on the outer periphery of said sleeve member and on the inner periphery of said tubular lar member allowing a telescoping motion between said sleeve and said tubular member and preventing relative angular motions therebetween, and wherein said drilling tools comprise a first group of symmetrically arranged bit members having a pin-like shape and extending radially in first radial planes transverse to each other and defining a first drilling periphery with a diameter greater than said tubular member, and a second group of bit members extending radially in other radial planes forming an angle with said first radial planes, said second group of bit members extending longitudinally beyond the longitudinal extension of said first group of bit members and defining a second drilling periphery having a diameter less than the diameter of said first drilling periphery.

Brief description of the drawing Further features and advantages of the device according to the invention will now be more apparent from the description of an embodiment given by way of a nonlimiting example in conjunction with the accompanying drawing, in which:

FIG. 1 is a fragmentary sectional view of the apparatus according to the invention;

FIG. 2 is a bottom view of the drilling tools used; and

FIG. 3 is a sectional view taken along line A-A' of FIG. 1.

Description of the preferred embodiment Referring to the drawing, the bore hole being drilled is indicated at 1. A working table is indicated at 2 while at 3 there is indicated a suction unit with an intake line 4 and a discharging line 5. A rotary table 6 which is supported on the working table 2 can be driven to rotate both in clockwise and counterclockwise directions and to which a string of hollow rods or pipe sections 7 is connected.

At the lower end of said string 7, there is arranged a hollow rod or sleeve member 8 provided with outer vertical longitudinal guideways 9.

Vertically moveable along said rod 8 is a drilling head 10, which is connected in a known way thereto, such as by means of a bush 13a and counter-bush 13b, and is internally provided with longitudinal seatings or grooves 11 designedto cooperate with the corresponding guideways 9.

The drilling head 10 has a tubular member 12 and a pin-like structure 13.

Said structure 13 is provided with four pin-like supporting members 14, at the ends of which hits 14a and 15a are provided integral therewith and defining a first group of bits.

Four bits 15 defining a second group of bits are provided at the lower and central portion of the head 10. The bits 15a are radially arranged on each member 14. In the figures, the cutting edges of the drilling tools are shown by thin and parallel lines defining a wedge like shape (see FIG. 2).

As may be best seen from FIG. 2 of the drawing the bits a of the first group of bits extend radially from the axis of the string in directions perpendicular to each other and the bits 15' of the second group of bits also extend radially to the axis of the string in directions perpendicular to each other and inclined with rcspect to the radial directions of the first group of bits. In addition, the second group of bits extends longitudinally beyond the bits of the first group. It may also be seen from the drawing that the bits 15a and 14a form together a T-like shape in which the bit 15a corresponds to the web portion of the T-like shape and the bit 14a corresponds to the flange portion of the T-shape.

Two cables 16 and 17, are connected to the upper portion of the tubular member 12. Through lugs 12a and to an upper common drive cable running over pulleys 19 and 20 of a crane structure 18 and terminating in a capstan 21.

A decantation tank 22 is adjacent the bore hole and is in communication thereto by a return duct 23 for drilling mud.

The operation is as follows.

By means of capstan 21, the drilling head 10 is raised to some extent vertically along the rod 8 and then allowed to fall by gravity onto the bottom to be drilled.

Of course, the bore hole is always kept full with drilling mud.

Upon each fall the bottom of the hole is further disintegrated by a to and from rotary motion of the drilling head about its vertical axis, preferably through an angle at least of 90, owing to the action of the rotary table 6.

The suction unit 3 conveys the disintegrated material up to the ground level and into a decantation tank 22 through the string of hollow rods 7, conduit 4 and conduit 5. In this tank 22, the cuttings and stones will deposit on the bottom while the drilling fluid will return to the bore hole 1 via the return duct 23.

It should be noted that tank 22 may be substituted by filtering devices, which are well known in the art, thus an illustration thereof being considered not necessary.

Furthermore the intake conduit 4, as known, could consist of a hose instead of the rigid duct 4 slidably and coaxially connected to the upper part of the hollow rods string 7.

I claim:

1. An apparatus for drilling wells under circulation of drilling mud, including a string of hollow rods allowing passage of drilling mud therethrough a tubular member having drilling tools connected at the lower end thereof and in telescoping relation with respect to said string, cable means connected with said tubular member and extending along said string beyond said well, driving means for reciprocating said tubular member in a direction parallel to said string and cooperating with said cable means, a rotary table for imparting intermittent angular movement to said drilling tools about the axis of said string, a pump for circulating the drilling mud and having its suction pipe connected with said string of hollow rods and wherein the improvement comprises a sleeve member surrounding a length of said string and rigid and coaxial therewith, said sleeve member having an outer diameter less than the inner diameter of said tubular member, cooperating longitudinal guideway means on the outer periphery of said sleeve member and on the inner periphery of said tubular member allowing a telescoping motion between said sleeve and said tubular member and preventing relative angular motions therebetween, and wherein said drilling tools comprise a first group of symmetrically arranged bit members having a pin-like shape and extending radially in first radial planes transverse to each other and defining a first drilling periphery with a diameter greater than said tubular member, and a second group of bit members extending radially in other radial planes forming an angle with said first radial planes, said second group of bit members extending longitudinally beyond the longitudinal extension of said first group of bit members and defining a second drilling periphery having a diameter less than the diameter of said first drilling periphery.

2. An apparatus according to claim 1, wherein said first group of bit members has bits facing the bottom of the well each of which has wedge like cutting edges defining the shape of a T with the web portion of the T extending in radial direction and the flange portion of the T peripherally arranged.

3. An apparatus according to claim 1, wherein said second group of bit members has bits each of which has radially extending wedge like cutting edges.

References Cited UNITED STATES PATENTS 1,562,449 11/1925 Herrin 262 1,709,074 4/1929 Herrin 175262 2,911,192 11/1959 Boucher 17556 3,012,621 12/1961 Baud et a1 175213 3,024,853 3/1962 Herbold 175213 CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner.

US. Cl. X.R.

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