US3460563A

US3460563A - Flexible drill string and operating apparatus therefor

Info

Publication number: US3460563A
Authority: US
Inventors: Sheldon O Bresin; Donald E Ross
Original assignee: Northrop Grumman Corp
Current assignee: Northrop Grumman Corp
Priority date: 1965-07-19
Filing date: 1965-07-19
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12

Description

S. O. BRESIN ET AL Aug. 12, 1969 FLEXIBLE DRILL STRING AND OPERATING APPARATUS THEREFOR Filed July 19, 1965 2 Sheets-Sheet l INVENTOfi SkeZdon O: Bresin Donald E. Ross 96 1 2030? 58. $04:

AGENT Aug. 12, 1969 s. o. BRESIN ET AL 3,460,563

FLEXIBLE DRILL STRING AND OPERATING' APPARATUS THEREFOR Filed July 19, 1965 2 Sheets-Sheet 2 Fig. 3

IN VENTORS S'keldon O. Bresz'n Donald E. Ross AGENT United States Patent M 3,460,563 FLEXIBLE DRILL STRING AND OPERATING APPARATUS THEREFOR Sheldon O. Bresin and Donald E. Ross, Huntsville, Ala.,

assignors to Northrop Corporation, Beverly Hills,

Calif., a corporation of California Filed July 19, 1965, Ser. No. 473,127 Int. Cl. B65h 75/46 US. Cl. ISL-355.26 Claims ABSTRACT OF THE DISCLOSURE A drilling assembly, adapted to operate in atmospheric or nonatmospheric environments, including a flexible member Wound on a reel member. The cylindrical portion of the reel member having a spiral groove formed therein, the flexible member in its assembled relation on the reel being received in the groove. The flexible member has high .and low pressure passageway therein and the concentric relation lending rigidity and stiffness to the flexible member when inflated. The assembly also includes a torque sensing unit functioning to arrest twisting action originating in one portion of the flexible member from being transmitted to other portions of the flexible member.

The present invention pertains to drilling facilities adapted to effect drilling operations and obtain core samples and more particularly to drilling equipment facilitating a drilling operation and the securing of core samples on the linear surface.

Briefly the present equipment comprises a flexible hose (drill string) wound in a continuous spiral groove formed in the outer cylindrical surface of a drum. The hose is of braided wire construction which in turn is coated with a flexible material, the material being non-pervious with respect to pressurized gas used in the subject drilling equipment. The coating material has convolutions formed in the outer surface thereof which mate with complimentary convolutions formed in the groove provided in the drum. The internal portion of the hose includes longitudinally extending passageways adapted to carry high and low pressure gas. One end of the hose is secured to sources of high and low pressure gas and rotates with the drum, the other end carries a gas actuated drilling tool. Constructed in the above manner it will be apparent that the hose is unwound from the drum, in response to a rotary movement of the latter, and will function as a segmented drill string having a degree of stiffness adapted to transmit a force sufiiciently great to effect a drilling operation.

Also it will be apparent that the drilling equipment as disclosed will eliminate the use of conventional drill strings (segmented casings) and, therefore, will eliminate the arduous task of positioning and connecting the same, thus enabling an astronaut to conserve his energy for for important activities.

Accordingly it is an object of the present invention to disclose drilling equipment constructed and functioning in a manner eliminating the need of utilizing for conventional segmented drill strings.

Another object is to provide drilling equipment which is self-contained requiring very little effort on the part of an operator of the equipment.

Another object is to provide drilling equipment including a hose which is alternately flexible and rigid when the equipment is deactivated and activated, respectively.

3,460,563 Patented Aug. 12, 1969 Another object is to provide drilling; equipment which is simple in design, economical to manufacture, efficient in operation and which may be easily adapted to any purpose for which it is intended.

Although the characteristic features of the present in vention are particularly pointed out in the appended claims, the invention itself, also the manner in which it may be carried out, will be better understood by re ferring to the following description taken in connection with the accompanying drawings forming a part of this application and in which:

FIGURE 1 is a perspective view of the drilling equipment as disclosed herein shown in its operating position associated with a space vehicle.

FIGURE 2 is an enlarged perspective view of the drilling equipment of FIGURE 1.

FIGURE 3 is a fragmentary sectional view of the drilling equipment of FIGURE 2 taken substantially on the line 3-3 of FIGURE 2.

FIGURE 4 is a cross-sectional view of the drill string comprising a component of the drilling: equipment shown inFIGURE2.

Referring to the drawings, FIGURE 1 shows drilling equipment 11 as disclosed herein as being utilized in a space environment, the equipment being attached to and used with a space or landing vehicle (not shown). Although the subject equipment is shown and described as being utilized in a space environment it should be understood that the equipment has other applications and may be utilized on earth to effect a drilling operation or for obtaining core samples.

During flight the equipment 11 is stored in a compartment (not shown) provided in the aforementioned landing vehicle, the compartment in turn is closed by a closure member 12. The member 12 functions during flight substantially as closing of the door housing the landing gear on an aircraft. The equipment 11 is moved between its stored position (not shown) and its operating position (FIGURE 1) on a support arm 14. The equipment 11 is rotatably mounted adjacent the midportion of the arm 14 while the right end of the arm (FIGURE 1) is pivotally attached to fixed structure of the landing vehicle.

The drilling equipment 11 includes a drum, drill strings, sealed compartment or chamber and an

electric motor

16, 17, 18 and 19, respectively, as best seen in FIGURE 2.

The drum 16 is constructed of light but strong material, it is of hollow construction constituting substantially a shell 21 pivotally supported on a shaft 22 by means of spider-like legs 23. The shaft 22 is in turn fixedly supported by the arm 14 at approximately the mid-point of the latter. A continuous spirally formed groove 24 is provided in the outer surface of the shell 21, the groove having a plurality of spaced depressions 26 defining convolutions formed therein adapted to mate with projecting (convolutions) formed in the outer surface of the drill string 17.

The drill string 17 constitutes a continuous flexible hose or conduit having high and

low pressure passageway

28 and 29, respectively, provided therein. The drill string 17 constitutes an outer conduit or hose 27 and an inner conduit 30. The inner surface of the conduit 27 is constructed of braided wire while its outer surface is coated with Teflon or similar material which is nonpervious to pressurized gas utilized in the equipment 11. The conduit 30, defining the passageway 28, is fabricated of rubber or similar material, is circular in cross-section and extends throughout the length of the conduit 27 and has a plurality of radially extending finn-like members 31 on its outer surface thereof. The members 31 function to maintain a concentric relation between the conduits 27 and and also to define the aforementioned passageways 29. The passageway 28 functions to carry high pressure gas from a compressor located in the chamber 18 to an air actuated drilling tool (not shown) located at the lower end of the drill string 17 while the passageways 29 function to return low pressure gas from the drilling tool to the chamber 18. The conduit 27 is covered with a flexible material, non-pervious to pressurized gas used in the equipment 11, for example, Teflon or other similar materials. Convolutions 26 (previously referred to) constitute spaced projections adapted to mate with convolutions 32 are provided in the surface coating of the conduit 27. Portions of the drill string 17 having a contacting and noncontacting relation with the drum 16 are referred to as major and minor portions of the drill string, respectively. Also provided in the covering of conduit 27 is a longitudinally extending groove 33 functioning in a manner presently explained.

The drill string 17, in its fully assembled position on the drum 16, is received in the groove 24 with one end thereof attached to the chamber 18 and a conventional air actuated drill tool attached to the other end.

Mounted in the chamber 18 is a compressor, electric motor, and high pressure gas reservoir (none of which are shown). The chamber 18 has a fixed relation with respect to and rotates with the drum 16, accordingly rotary seals are not required between the aforementioned reservoir 18 and the conduits 27 and 30.

A slide rod and a

slide bar

34 and 36, respectively, have a fixed relation with respect to the arm 14 and constitute components of the equipment 11. The slide rod 34 carries a roller 37 having a concave surface, the roller is adapted to slide on the rod 34 as the drill string 17 is wound and unwound from the drum 16. The bar 34 is positioned with respect to the drum 16 so that the roller 37 functions to maintain the drill string 17 firmly in the groove 24 with the

convolutions

32 and 26 in mating relation.

The slide bar 36 carries a block member or torque sensor unit 38 adapted to slide on the bar 36 as the drill string is wound and unwound from the drum 16. The member 38 has an aperture provided therein defining a projection 39 (not shown) adapted to mate with the groove 33.

The motor 19 is of reversible type and functions to drive the drum through a conventional device 41 adapted to impart a predetermined stalling torque to the drum 16 at such time as the drill string 17 is being unwound. The motor 19 exerts a torque exceeding the unwinding stalling torque referred to above at such time as the drill string is being rewound.

A drill string guide 42 provides a connecting link between the drum 16 and a surface casing 47. It consists of an open end rigid tube 43 which is split and hinged so that it can be placed around the aforementioned drilling tool and coupled to the surface casing 47 through a flexible bellows-like coupling 44. Thus it will be apparent that drill string alignment is provided between the latter and the hole being drilled.

The operation of the equipment 11 follows, at such time as the aforementioned lunar vehicle arrives at its destination the closure member 12 is opened and the equipment 11 pivotally moved to its operating position substantially as shown in FIGURE 1, a support brace 46 is secured to fixed structure of the landing vehicle thereby maintaining the arm member 14 in a fixed position. The drum 16 is now rotated in a direction causing the drill string 17 to unwind from the drum 16 until the aforementioned air activated drilling tool, secured to the end of the drill string 17, contacts the lunar surface. The aforementioned compressor is now activated and a drilling operation initiated. As soon as a hole is drilled to a predetermined depth the drilling operation is discontinued, the drilling tool withdrawn and the surface casing 47 installed in the hole. The drill string guide 42 is also installed as described above and the drilling continued. The material (core sample removed by the drilling tool is urged upwardly and collected in the drill guide 42. When the drill guide is full the drilling operation is discontinued, the drill guide emptied, the material labeled for later identification and the operation repeated.

The main or outside conduit 27 of the drill string 17 being constructed of braided wire it will be apparent that the drill string will exert a predetermined force on the drilling tool at such time as the drum 16 is rotated in a direction causing the drill string to unwind. This action is enhanced by the fact that the longitudinal force developed in the high pressure passageway 28 exceeds that produced in the low pressure passageways 29. Thus the conduit 27 has a tendency to remain straight and rigid, in effect the pressurized gas increases the column strength of the drill string 17. Inert gas such as nitrogen or the like is recirculated in the equipment 11 to effect operation of the drilling tool.

While in order to comply with the statute, the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the method and means herein disclosed comprise several forms of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

We claim:

1. In drilling equipment the combination comprising: a drum-like member having a spiral groove formed in the cylindrical portion thereof; said spiral groove having a plurality of spaced depressions defining convolutions formed therein; a flexible inflatable hose-like member including major portions normally positioned in said groove and having a plurality of spaced projections in the outer surface thereof adapted to mate with the convolutions in the groove and minor portions extending substantially tangentially with respect to the cylindrical portion of said drum; said flexible member defining a compound passageway; said compound passageway comprising a plurality of longitudinally extending passageways adapted to have pressurized fluid confined therein and functioning to render said major and minor portions rigid at such time as pressurized fluid is confined in said passageways; and means functioning to maintain said major portions in said groove and releasing said minor portions from said drum during an inwinding operation of said drum.

2. In drilling equipment as set forth in claim 1: in which the outer wall of said hose-like member is constructed of braided wire covered with rubber-like material; said compound passageway constituting a high and a low pressure passageway having a concentric relation and in which the low pressure passageway surrounds the high pressure passageway; the rubber-like material defines a groove extending longitudinally throughout the length of said hose-like member; a torque sensor unit located on a line having a tangential relation with respect to the cylindrical portion of said drum; portions of said torque sensor unit defining an aperture having an axially extending projection formed therein; and said hose-like member passing through said aperture with said projection received in said groove whereby torque developed in said minor portions will not be transmitted to said major portions.

3. In drilling equipment as set forth in claim 1: in which the outer wall of said hose-like member is constructed of wire braid covered with rubber-like material; and said plurality of passageways including at least two passageways, one adapted to carry fluid at a high pressure and the other fluid at a lower pressure.

4. In drilling equipment as set forth in claim 3: in which said high and low pressure passageways have a concentric relation with the low pressure passageway surrounding said high pressure passageway.

5. In drilling equipment as set forth in claim 3: in which the rubber-like material defines a groove extending longitudinally throughout the length of said hose-like member; a torque sensor unit located on a line having a tangential relation with respect to the cylindrical portion of said drum; portions of said torque sensor unit defining an aperture having an axially extending projection formed therein; and said hose-like member passing through said aperture with said projection received in said groove whereby torque developing in said minor References Cited UNITED STATES PATENTS Smith 137355.23 Krieg 137--355.17 Finneburg et al. 242-54 X Palm 137355.19 Wolfe 137355.26 X Hannay 137355.2 X Roark 137--355.23 X Kaufman 242-107 Goodliffe et al. 137355.26 Powell 137-3552 X portions will not be transmitted to said major portions. 15 SAMUEL SCOTT, Primary Examiner