US3486571A

US3486571A - Horizontal drilling of well bores from tunnels

Info

Publication number: US3486571A
Application number: US717767A
Authority: US
Inventors: Daniel Silverman
Original assignee: Pan American Petroleum Corp
Current assignee: Pan American Petroleum Corp
Priority date: 1968-04-01
Filing date: 1968-04-01
Publication date: 1969-12-30
Anticipated expiration: 1986-12-30

Description

Dec. 30, 1969 D. SILVERMAN HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS Filed April 1, 1968' 9 Sheets-Sheet 1 m mm 5 IE 1 2 L3 cm om ,[l II F F P E 3; 4 u mm\ mm E E mwm m K INVENTOR. DAN I EL SILVERMAN ATTORNEY HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS Filed April 1, 1968 Dec. 30, 1969 o. SILVERMAN 9 Sheets-Sheet 2 FILL INVENTOR. DANIEL SILVERMAN ATTORNEY Dec. 30, 1969 D. SILVERMAN- 3,485,5

HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS Filed April 1, 1968 9 Sheets-Sheet 5 FIG.5

INVENTOR.

DANIEL SILVERMAN BY ax? naw A T TORNE Y Dec. 30, 1969 D. SILVERMAN 3,486,5

HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS Filed April 1, 1968 9 Sheets-Sheet L INVENTOR.

DANIEL SILVERMAN A TTORNE Y 9 Sheets-Sheet 5 M R M MR E E V V mu 8 IL E N A D ymm ATTORNEY 'Dec. 30, 1969 D. SILVERMAN HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS Filed April 1, 1968 FIG. 7

O Qua/y 8 7 HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS Filed April 1, 1968 Dec. 30, 1969 D. SILVERMAN 9 Sheets-Sheet 6 INVENTOR. DANIEL SILVERMAN ATTORNEY Dec. 30, 1969 0. SILVERMAN HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS 9 Sheets-Sheet '7 Filed April 1, 1968 FIG. 9

INVENTOR. DAN l-EL SILVERMAN A TTORNEY Dec. 30, 1969 n. SILVERMAN HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS 9 Sheets-Sheet 8 Filed April 1, 1968 3 N: mW% 0Q /MAA/ INVENTOR. DANIEL SILVERMAN Qr A M ATTORNEY 30, 1969 a. SILVERMAN 3, ,57

HORIZONTAL DRILLING OF WELL BORES FROM TUNNELS Filed April 1, 1968 9 Sheets-Sheet 9 INVENTOR.

DANIEL SILVERMAN BY A TTORNE Y United States Patent G 3,486,571 HORIZONTAL DRILLING F WELL BORES FROM TUNNELS Daniel Silverman, Tulsa, Okla, assignor to Pan American Petroleum Corporation, Tulsa, Okla, a corporation of Delaware Filed Apr. 1, 1968, Ser. No. 717,767 Int. Cl. E21]; 7/12; E21c /00; E01g 3/04 US. Cl. 175-5 18 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a method and apparatus for drilling horizontal well bores from tunnels. A cogwheellike train is provided on a substantially horizontal (sloping) track. The vehicle contains rotating means having its axis of rotation parallel to the direction of motion of the vehicle. The string of drilling pipe extends substantially horzontally from the rotating means to a borehole at the end of the tunnel. Means are provided to removably join in fluid sealing contact the drill pipe through the rotating means to mud pumps. Directional drilling means are provided to cause the borehole to take a selected path. The path of movement of the vehicle means is rather long, e.g., 2,000 feet or more. Thus, when making a trip into the borehole and out, 2,000 feet of drill pipe can be removed before it is necessary to break any joints. This greatly decreases the trip time required. In one embodiment the horizontal tunnel is in the earth beneath a body of water and access to the tunnel is through telescoping casing extending from the tunnel to above the surface of the water.

This invention relates to the art of drilling boreholes in the earth, particularly in the search for oil and gas. It relates especially to a method of drilling substantially horizontally into the end of a tunnel and then controlling the direction of the drilling.

BACKGROUND In the search for oil and gas, boreholes are drilled deep into the earth. The most conventional method of drilling such boreholes is the so-called rotary drilling method. In this system a vertical derrick is positioned above the point on the earth at which it is desired to start the borehole. A drill bit is suspended at the lower end of a string of drill pipe held vertically within the derrick. The drill string extends through a horizontal rotary table which when operated imparts a rotating motion to the square kelley portion of the vertical drilling string and its accompanying bit. While the drill pipe is being rotated, mud pumps force a drilling fluid, commonly called mud, down through the drill pipe, through the bit and up the annulus between the drill pipe and the walls of the borehole. As the hole deepens, additional joints of drill pipe, ordinarily about 30 feet long, are connected into the drill string. When the bit is dulled, it is necessary to remove the drill string from the hole so that the bit may be changed. This removal is accomplished by raising the drill pipe up into the derrick and removing one joint, then raising the drill pipe an additional joint and removing this joint, and repeating this until the bit has been brought to the surface.

As the search for oil and gas moves outwardly onto open waters such as the continental shelf, Cook Inlet, etc., additional problems in drilling are encountered. In these areas such as the Cook Inlet, storms, wave motion and currents cause tremendous problems to drilling either from floating vessels or drilling from fixed platforms. In this type operation there are two outstanding problems:

Patented Dec. 30, 1969 one, the battle with the elements and, two, the pulling of the drill pipe joint by joint. This invention provides a drilling method and apparatus which eliminates or greatly reduces the magnitude of both of these problems.

BRIEF DESCRIPTION OF THE INVENTION In this system a substantially horizontal or slightly sloping elongated surface is provided. A vehicle means is maintained to move along this surface under controlled power. Rotating means are provided on this vehicle means in which the axis of rotation is parallel to the direction of motion of the vehicle means. Thus, the axis of rotation is substantially horizontal. Pump means are provided to supply drilling fluid to or through the rotating means to the drill pipe. Means are further provided to support the pipe along the track between the rotating means on the moving vehicle and the well head equipment through which the drill pipe enters the borehole. One modification of this latter-mentioned means is adapted to disconnect that portion of the drill pipe between the vehicle and the well head and store it on a horizontal storing rack.

It is contemplated that the most popular use of this system is in drilling in offshore areas. In this concept the tunnel is started from the surface of the land and goes out under the water at a gentle slope, e.g., not over about 15 to 30 degrees. The tunnel may extend several miles or more until it reaches the drilling site. Then the wells are drilled from the end of the tunnel, first in a substantially horizontal direction, and then after 500 to 1,000 feet or so of drilling at the same slope as the tunnel, directional drilling means are used to cause the well to bottom at the desired location. Such a system is quite suitable for the drilling in Cook Inlet in Alaska, for example, or along the California coast.

Various objects and a better understanding of the invention can be had from the following description taken in conjunction with the drawings in which:

FIGURE 1 is a side view of the drilling system positioned in a tunnel;

FIGURE 2 is a top view of the equipment shown in FIGURE 1;

FIGURE 3 is a side view in the tunnel of the track and the vehicle thereon for moving the pipe horizontally;

FIGURE 4 is a top View of the apparatus of FIG- URE 3;

FIGURE 5 illustrates a switching system whereby the equipment of FIGURE 1 can be used to drill a plurality of wells at the end of a tunnel;

FIGURE 6 illustrates pipe gripping means which in FIGURE 1 are placed near the well head assembly;

FIGURE 7 illustrates a drill pipe gripping means mounted on the front of the vehicle of FIGURE 3;

FIGURE 8 illustrates pipe gripping and rotating means for uncoupling pipe at the well head end;

FIGURE 9 illustrates pipe support means for supporting and placing in storage the joints of pipe in FIGURE 3;

FIGURE 10 illustrates the vertical rotary table of FIGURES 1, 2, 3 and 4;

FIGURE 11 illustrates a telescopic extension caisson for entry into a horizontal tunnel placed in the earth beneath a body of water,

Attention is first directed to FIGURES 1 and 2 which show a preferred embodiment for a system useful for horizontal drilling. Shown in FIGURE 1 is a substantially horizontal tunnel 10 having a bottom 12 and a top 14. Along the bottom of this tunnel is a substantially horizontal (sloping) elongated surface. This particular surface takes the form of a railroad track 16. The slope of this tunnel surface should not be over about 15 to 30 degrees from the horizontal. The vehicle means which is adapted to move along the surface takes the form of a special type railroad engine or locomotive 18. This engine as shown is gear driven by a pinion gear which mates with elongated rack 20 so that proper traction can be made to obtain the power required when pulling drill pipe out of the hole.

Opposite engine 18 is a Well head 22 which is secured to a casing 24 which is mounted in hole 27 which is substantially parallel to the horizontal sloping surface of the bottom of the tunnel 10. The casing 24 is cemented in the hole 27 so as to form a firm anchor for well head 22. A string of drill pipe 28 is supported between the engine 18 and the well head 22. As a Section of drill pipe 28 between the engine 18 and the well head 22 can be long, e.g., 500 to 2,000 feet or more, there are provided means for supporting the drill pipe along this horizontal span. This includes a plurality of track support cars 30A to 30n. As can be seen in FIGURE 2, the support cars 30A have an arm member 32A having bearings 34A at the endof which pipe 28 is supported. As will be explained more fully in relation to FIGURE 9, this pipe supporting transfer means 30A can lift the pipe 28 and place it on pipe rack 36 which is made of upright members 36A, each having upwardly sloping support pegs 36B thereon.

Means are also provided for rotating the pipe, supplying mud to the drilling system and returning it, The rotating means is schematically shown in FIGURE 1 as a vertical rotary table 38 (with horizontal axis). As will be seen more clearly when FIGURE is discussed, this provides means to rotate drill pipe 28 and for directing a drilling fiuid into the pipe. Well head 22 has an outlet connection 40 which is connected to the annulus 26 between drill pipe 28 and casing 24. This is for the return of mud to a mud pump, not shown. Well head 22 permits drill pipe 28 to extend therethrough in a rotating and sliding but sealing relationship. Suitable well heads are well known. As shown in FIGURE 3, a mud suction line 42 is connected to a mud pump 44 on engine 18. The other end of mud line 42 extends to a mud reservoir, not shown. This mud reservoir is preferably at the surface; however, if the tunnel is too long for this to be practical, the mud pit is enclosed in a selected compartment or tank near the well head. The output of mud pump 44 is connected through a mud conduit 46 to the mud inlet of vertical rotary table 38.

Engine 18 has a power means such as motor 48 Which is preferably an electric motor obtaining its power from electrical conductor 50 which gets its power from the surface. Motor 48 has three pulleys and

shafts

48A, 48B and 480 which are used, respectively, to drive mud pump 44, cog gears 50 and rotary drive means 38.

I shall now discuss that portion of FIGURE 3 which has to do with the clamping or holding of the pipe when it is desired to disconnect joints of the pipe. This includes clamping means 52 (described more in detail in FIGURE 7 and its discussion) and carried on the front end of engine 18. During normal operations this clamping means 52 permits the pipe to pass therethrough without touching. When actuated, the device rigidly clamps the pipe 28. At the other end of drill pipe portion 28 adjacent well head 22 is a second clamping means 54. This clamping means 54 is shown more in detail in FIGURE 6 and will be described hereafter. Ordinarily the pipe 28 passes through pipe rotating means 56 without contact. If it is desired to rotate the pipe means 56, the pipe is gripped and then the device is rotated, thus effecting a coupling or uncoupling of the pipe from the joint held by pipe gripping means 54.

Before discussing the details of the various component parts of the embodiment shown in FIGURES 1 through 4, it is believed that a brief review of the operation of this system will be helpful. Tunnel 10 is first dug in any known manner. If it is underwater, it can be sealed against invasion of such water if necessary. Track 16 is laid and anchored to the earth. Pipe supports 36 are erected along the wall thereof. A supply of drill pipe 28 is placed upon supports 36. Supplies are carried into the tunnel on track 16 by any conventional railroad type carrier. Lateral transfer cars 30A which are placed on lateral tracks which have been laid on the floor 12 of tunnel 10 are used to transfer drill pipe 28 to and from the wall racks 36.

The larger longitudinal borehole 27 is first drilled into the end of tunnel 10. This corresponds to the spudding-in operations of the conventional wells. In this system, lateral support means 30A is used to remove a joint of pipe 28A from pipe racks 36. The lead end of pipe joint 28A is connected to a drill sub and a drill bit and extends through pipe gripping means 54 against the end of the tunnel. (At this time no longitudinal borehole has been drilled.) The other end of pipe section 28A is connected to vertical rotary drilling table 38 and of course extends through pipe gripping means 52 which does not touch it. Mud pump 44 is connected through tube 42 to the mud pit, not shown. This mud pit is enclosed so that any vapors or gas therefrom will be vented or removed to the surface, Drilling is now commenced by simultaneously starting up the mud pump and rotating pipe 28. When drilling is first oommenced, the section of pipe 28 between engine 18 and well head 22 should be relatively short, e.g., 2 or 3 joints of 30-foot pipe. This is so that the engine can push against the pipe without excessive bending to facilitate drilling of the borehole. This forward push is obtained by rotation of cogwheel 50 against the gear rack. As drilling progresses, engine 18 moves toward the end of the tunnel. Hole 27 is drilled a sufficient distance into the wall so that well casing 24 can be securely cemented therein to form an adequate anchor for well head 22. When hole 27 is drilled a sufficient distance, the drill pipe 28 is removed by moving car 18 away from the borehole. The large diameter bit is removed and replaced by a bit of the proper size for the drilling of the regular hole.

After hole 27 is drilled, casing 24 is securely cemented therein. A well head 22 is then connected to casing 24. Mud return line 40 of the well head is connected to the mud pit. Annulus 26 is former between casing 24 and drill string 28.

Before starting drilling with the small diameter bit, additional drill pipe 28 is inserted into the system. Before placing additional pipe into the system, the drill bit drills the horizontal hole as far as it can conveniently do so. When the well head 22 is approached by the engine 18, pipe gripping means 54 (which is secured to the floor of the tunnel near the well head) is actuated to hold the pipe and the vertical table 38 is turned in a reverse direction to disconnect the pin joint 53 from the pipe 28.

The engine 18 is thus free of the pipe 28. At this time engine 18 is moved backwardly to the left, away from well head 22, the length of one or two joints of pipe, depending on how many are to be added. Lateral pipe transport means 34A then picks up the joints of drill pipe 28A from the wall rack and transports it into alignment between end 53 on engine 18 and the end of pipe 28 extending out from well head 22 and clamped by means 54. The right or lead end of the newly inserted pipe section 28A is connected into that portion of the pipe string 28 extending out of the pipe gripping means 54. The other or trailing end of the newly inserted section 28A is connected to pin joint 53. Then vertical rotary table 38 is actuated to tightly connect pin 53 to the end of inserted section 28A and section 28A to section 28. Now the system is ready to start up the mud pumps and drill as described above. This procedure just described is repeated as necessary until the desired depth of the hole is obtained.

As mentioned earlier, after the hole is drilled some distance, such as 500 to 1,000 feet, at about the same slope as the floor of the tunnel, it is normally desired to deflect the hole downwardly. This can be done with commercially available whip stocking or directional drilling attachments to apply to the drill string 28 adjacent the bit.

Frequently it is desired to change a bit before a hole is completely drilled. This is because the bit is dull and the rate of penetration becomes unbearably slow. This system is ideally suited for pulling and running strings of drill pipe out of and into the hole. Ordinary drilling rigs can only pull about two joints of pipe at a time before it has to uncouple the joint, grip the pipe, lower the two disconnected joints and stack them, then reconnect to the remaining drill string and repeat the operation. This is very time consuming and on deep wells can take 6 to 8 hours or longer just to pull the pipe. My system is ideally suited for pulling the pipe. I prefer that my track be at least 2,000 feet long. Then when I need to pull a string of pipe I can pull 2,000 feet before I have to uncouple any pipe. At that point I uncouple 2,000 feet, use my lateral loader 30A, and place the 2,000 feet at one time on racks 36. I then move my engine 18 back toward well head 22 where I reconnect to the remaining drill string 28. I then pull out 2,000 more feet. For a 10,000-foot well then, it is seen that I only have to disconnect the pipe five times as against about 150 times in conventional drilling. This is a tremendous saving in time. Further, when I put the new hit on and go back in the hole, I only have five connections to make, whereas in conventional rigs they have 150. It is thus seen that by the use of my system there is tremendous advantage in time required for pulling and replacing bits.

Attention will now be directed toward some of the individual components in the systems of FIGURES 1 through 4. First, I shall discuss pipe gripping means 54 which is positioned near well head 22. In this regard attention is directed to FIGURE 6. Shown thereon are two upright members 58 which are braced by members 60 to a base 62. Supported between the two upright mem bers 58 is a top beam 64 upon which is mounted a motor 66. Two vertical shafts 68 are securely positioned between beam 64 and base 62. Each shaft 68 has an upper threaded portion and a lower threaded portion, with the upper portion being either left-handed or right-handed threads and the lower portion having opposite type threads. There is provided an upper clamping block 70 having teeth 72 and a lower clamping block 74 having teeth 76. These clamping blocks 70 and 74 have

ears

70A and 74A which have bores having internal threads to mate with the threads of shaft 68. Thus, rotation of the shaft 68 in one direction pulls clamping blocks 70 and 74 apart, whereas the rotation in the opposite direction moves them together. This is controlled by the operation of reversible motor 66. The clamping blocks 70 and 74 are in sliding contact with support plate 65 securely fastened to members 58. The plate 65 has an opening 67 through which the drill pipe passes. When the drill pipe is clamped in blocks 70, 74, the weight of the drill pipe is carried by these blocks which press against plate 65 for support. Beams for holding the shafts in place and transmitting the power from the motor 66 are well known and will not be discussed in detail.

Attention is next directed to FIGURE 7 which shows details of the pipe gripping means 52 as shown in FIGURE 3 as being connected to the engine 18. Shown thereon are two upright members 78 supported from a base 80. Two clamping

arms

82 and 84 are pivotally supported on

rods

86 and 88 which are supported between upright member 78. These

arms

82 and 84 have pipe gripping means 83 shaped to fit the drill pipe 28. Each

arm

82 and 84 has

members

90 and 92, respectively, which contain vertical bores through which is mounted a vertical threaded shaft 94, the upper thread section being either leftor right-handed, and the lower section being the opposite. A motor 96 is provided to drive shaft 94. Rotation of shaft 94 in one direction or the other opens or closes the clamping

arms

82 and 84. It will be noted that there is an opening 85 through which the 6 pipe can be moved horizontally into or out of the clamping area of these two arms.

Attention is next directed to FIGURE 8 which shows the details of a suitable pipe rotating means 56 as shown in FIGURE 3. This includes an upright member 98 supported from a base 100 upon which is mounted a drive motor 102. Clamping means are provided for releasably clamping the pipe. Rotating means are provided to rotate the clamping means. The clamping means includes an open end pair of

arms

104 and 106 which are pivotally supported by

axes

108 and 110, respectively.

Axes

108 and 110 are supported from partial gear ring 112 which has an open place 114 which is aligned with the open end of

arms

104 and 106 for receiving the drill pipe. Ring 112 is supported from upright member 98 by a plurality of holding members such as pins 116 and discs or rollers 118. There is also provided means 120 for causing

arms

104 and 106 to move closer together to engage pipe therein. Pins 109, supported by ring 112, limits the movement of

arms

104 and 106.

In operation, pipe section 28A is inserted through gap 114 and is placed concentric with the opening between the teeth in

arms

104 and 106. During normal drilling operations these arms are moved far apart until they contact pins 109. Thus, the drill pipe does not contact the device of FIGURE 8. When it is desired to uncouple a portion of the pipe, means 120, which can be a hydrau lically operated piston, is actuated to cause the

arms

104 and 106 to tightly grip the pipe. Then motor 192 is actuated to drive power gear 112 in the direction to uncouple the pipe. When pipe is uncoupled,

arms

104 and 106 are released and the pipe removed through gap 114. This device of FIGURE 8 can he used to either loosen or tighten up joints by proper excitation of motor 102.

Attention is now directed to FIGURE 9 to show greater detail of the lateral moving and support means. This includes a cart 122 mounted upon rails 124. The cart is preferably driven by a reversible electrical motor, not shown, which are commercially available. Mounted on the top of cart 122 is a beam 126 which is pivotally mounted about horizontal axis 128. The pivoting of this arm 126 is controlled by rod 130 which can be driven up or down in any conventional manner. Mounted along the member 126 is a drive chain 132. This drive chain can be driven in any conventional manner as by an elec trical motor with a drive shaft coupled to the chain. Fixed to one point of chain 132 is pipe cradle 134. This cradle 134 has a V-shaped face upon which are mounted

roller bearings

136 and 138. These

bearings

136 and 138 contact and support the pipe 28. Cradle 134 is pulled along guide rails 140 by chain 132.

In operation, the device of FIGURE 9 is operated to support pipe 28 between engine 18 and well head 22 to keep the pipe from sagging. The distance between these pipe support carts 122 is dependent upon the strength and size of the pipe, For ordinary coring drill pipe, it is anticipated that they would be about 25 to 50 feet apart, for example. Arm 130 is raised or lowered so that cradle 134 is the right elevation for proper support.

The device of FIGURE 9 in addition to being used as a pipe support means is also used as a lateral movement means. When a section of drill pipe is disconnected, cradle 134 on each cart 122 involved is moved to the other end of arm 126, toward the pipe racks, by chain 132. Then the elevation of that end is adjusted as necessary so that the pipe may be slipped over the proper support pegs. Then cart 122 is moved toward the pipe support means 36, as shown in FIGURE 1. Piston arm 130 is then lowered until the pipe is supported by the support pegs. Further lowering of arm 126 lets cradle 134 be free so that it can be returned to the other end for what other operation may be necessary.

Attention is next directed to FIGURE 10 which illustrates the vertical rotary table of FIGURES 1 through 4. This includes three basic parts: the pin means 142 for connecting to a joint of drill string, drive means 145 for supplying power to drive pin 142, and inlet means 146 for connecting drilling fluid through the system into the drill pipe. These items are all supported within a housing 148. Mounted with housing 148 is a hollow drive shaft 150 which is supported by

bearings

152 and 154. This shaft 150 extends external of the housing and is connected to connecting pin 142. Hollow drive shaft 150 is provided with a bevel gear 156 which mates with bevel drive gear 158. This drive gear 158 is connected through shaft 150 to a pulley 145 which is connected to the motor 48, as shown in FIGURE 3. Mud line 46 is connected into inlet 146. Inlet 146 is in fluid communication with the interior of drive shaft 150. Packing means 160 prevents the drilling fluid from inelt 146 from reaching the rest of the housing of the rotary gear drive.

Various modifications of this device and different adaptations can be made. For example, the arrangement of FIGURE illustrates how the device can be used to drill many holes from one tunnel. FIGURE 5 is a top view of such an arrangement. As can be seen, the well hole end of the tunnel has been spread out like a fan. There are a plurality of tracks 170 with a switch 172 for directing the drilling equipment onto whichever track it is desired. As can be seen, there are a plurality of holes 174 with well heads 176. The same horizontal drilling equipment described above can be used for each of the holes 174 to 17411. The carts 178 can be used for each of the tracks 170-170n, However, the tracks for these carts 178 may have to be taken up or laid down, as necessary, to obtain proper spacing relationship with the drilling equipment for each track location, or appropriate track crossing units must be provided.

Although it is contemplated that the greatest use of this system will be those cases where the tunnel is commenced or opens onto land and extends out under a body of water as described above, it is not to be limited to that use. It is also useful for other areas. For example, it can be used for drilling on the surface of the earth, or as shown in FIGURE 11. In this latter system, tunnel 190 is positioned or dug in the earth beneath a body of water 192. Access both for digging this tunnel 190 and for future operations therein is through an extensible caisson 194 and a cased shaft 196. Extensible caisson 194 includes a lower larger diameter caisson 198 and an upper extensible portion 200. Sealing means 201 are provided therebetween. A work platform 202 is mounted on the upper end of the caisson extension 200. Under normal operating conditions the caisson is extended as shown in FIGURE 11. Then equipment and personnel can be transferred down the shaft as necessary. The drilling is carried out in tunnel 190 in a quiet environment without regard to currents or wave motion of the body of water 192. If a storm should come, all that is necessary is to lower upper section 200 of the caisson downwardly so that the platform 202 is below most of the effect of the waves and storm, When the storm subsides, the platform is again raised so that transfer of material and personnel can be again carried out as necessary.

Means are provided as indicated schematiaclly by the flexible pipe 250 attached to the side of the caisson 198, and the float 251 which supports the pipe. The purpose of the pipe and float are to provide means for pump 252 to pump in fresh air for the workmen. Also pump 253 and pipe 256 are provided to expel waste gases. By these means work can continue in the tunnel 190 even though the extension 200 is retracted because of a storm.

While the above embodiments have been described with a great deal of detail, it is possible that modifications can be made therefrom without departing from the spirit or scope of the invention.

I claim:

1. A borehole drilling system for use with drill pipe and drill bits which comprises:

vehicle means;

a substantially horizontal elongated surface for supporting said vehicle means, said vehicle means supported by said surface;

power means in operating relation to said vehicle an said surface, including guide means to move said vehicle along said surface in a substantially longitudinal direction;

rotating means mounted on said vehicle means, the axis of rotation being parallel to the direction of motion of said vehicle means, threaded means'for joining drill pipe to said rotating means to be rotated thereby, said drill pipe joined to said rotating means. said rotating means having a drilling mud inlet and means to sealingly and fluidly connect said inlet to said drill pipe; and

means attached to said vehicle means adjacent to said rotating means for releasably clamping said drill pipe against rotation whereby when said rotating means is rotated and said drill pipe clamped, the threaded joint between said drill pipe clamping means can be broken.

2. The system as in claim 1 including first means attached to said surface for clamping said drill pipe against longitudinal and rotational motion;

second means attached to said surface between said first means and said vehicle, in the vicinity of said first means, for rotation of said drill pipe whereby a threaded point of said drill pipe between said first and second means can be broken.

3. The system as in claim 1 including pump means in operative relation to said rotating means to supply drilling fluid to said drilling mud inlet.

4. A system as defined in claim 1 wherein said guide means includes track means attached to the elongated surface.

5. A system as defined in claim 4 wherein said means to move said vehicle includes a rack attached to said track and a pinion on said vehicle means.

6. A system as defined in claim 4 including a tunnel in the earth and said horizontal elongated surface being upon the floor of said tunnel.

7. A system as defined in claim 6 in which said tunnel is in the earth underlying a body of water and including a vertical shaft extended upwardly from said tunnel to the sea floor and a caisson extending upwardly through the water to above the surface thereof.

8. A system as defined in claim 7 in which the caisson has an extensible member such that it can be extended to above and retracted to below the surface of the water.

9. A system as defined in claim 1 including means to support said pipe between said vehicle and the end of said elongated surface.

10. A system as defined in claim 9 in which said support means includes carts laterally movable with respect to the path of said vehicle means.

11. A system as defined in claim 1 in which said means to rotate said drill pipe includes:

a housing having a mud inlet;

a barrier in said housing having a port therein;

a hollow drive shaft inside said housing and extending external a wall of the housing on the oppoiste Side of said barrier from said mud inlet, said drive shaft sealingly fitted into said port;

bearing means supporting said hollow drive shaft in said housing;

power means to rotate said hollow drive shaft; and

means on the external end of said hollow drive shaft for connecting to said drill pipe and for applying axial force and torque to said drill pipe.

12. A system as defined in claim 11 including a track means supported by said elongated surface.

13. A system as defined in claim 6 including a well head supported adjacent one end of the tunnel, the bore therethrough being parallel to the said elongated surface;

a. pipe gripping means adjacent said well head and supported by the floor of said tunnel when actuated securely grips a pipe and when retracted permits the pipe to pass therethrough;

a pipe rotating means adjacent said pipe gripping means and supported from the floor of said tunnel, said pipe rotating means having a side opening so that pipe can be inserted into and removed therefrom.

14. A system as defined in claim 13 in which said pipe rotating means includes a motor having a powered gear on its shaft;

:1 ring gear mated with said power gear, a portion of said ring gear removed leaving an opening therein; an upright support member;

multiple bearing means protruding from said upright support means arranged in a circle for supporting said ring gear member in rotation;

a pair of tong arms, each tong arm pivotally mounted at its end to said gear ring at points opposite said opening; and

means attached to each of said tong arms to move said tong arms about their axis to grip or release pipe. 15. A borehole drilling system for use with conventional drill pipe and drill bits, the improvement comprising:

a substantially horizontal elongated surface; vehicle means mounted on said surface and adapted to move along such surface in the direction of the elongation; rotating means on said vehicle means, the axis of rotation being parallel to the direction of motion of said vehicle means; a pump means in operative relation to said rotating means to supply drilling fluid; said rotating means including means to removably join in fiuid sealing contact said drill pipe to said rotating means, said drill pipe joined to said rotating means, and means attached to said vehicle means adjacent to said rotating means for clamping said drill pipe against rotation whereby when said rotating means is rotated and said drill pipe clamped, the threaded joint between said drill pipe clamp and said rotating means can be broken. 16. The system as in claim 15 including power means in operative relation to said vehicle and said surface, in-

eluding guide means, to move said vehicle along said surface in a substantially longitudinal direction.

17. A vertical rotary table for supplying axial force and torque to and supplying mud to a horizontal drill pipe which comprises:

a housing having a mud inlet;

a barrier in said housing having a port therein;

a hollow drive shaft inside said housing and extending external a wall of the housing on the opposite side of said barrier from said mud inlet, said drive shaft sealingly fitted into said port;

bearing means supporting said hollow drive shaft in said housing;

power means to rotate said hollow drive shaft; and

means on the external end of said hollow drive shaft for connecting to said drill pipe and for applying axial force and torque directly to said drill pipe.

18. A pipe rotating means including:

a motor having a powered gear on its shaft;

a ring gear mated with said power gear, a portion of said ring gear removed, leaving an opening therein; an upright support member;

means attached to each of said tong arms to move said tong arms about their axis to grip or release pipe.

References Cited UNITED STATES PATENTS 1,753,511 4/1930 Grant 5 2,128,240 8/1938 Foster 17562 X 2,656,683 10/1953 Riva 1755 X 2,835,472 5/1958 Osborn 175-218 X 2,976,942 3/1961 Pitcher 17562 X 2,989,294 6/1961 Coker 1755 X 3,089,549 5/1963 Robbins 175-62 X 3,173,502 3/1965 Overby 175214 X NILE C. BYERS, JR., Primary Examiner US. Cl. X.R.

" UNITED STATES PATENT UFFTUE CERTIFICATE OF CORRECTION patent No. 3386571 Dated December 30, 1969 Inventor(s) Daniel Silverman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line +3, "selected" should read -sealed--.

Column L, line ll, "former" should read --formed-.

Column 6, line 29, 1 9 2" should read --102--.

Column 7, line 15, "inelt" should read -inlet-.

Column 7, line 60, "schemetiaclly" should read --schema.tica.lly-.

Column 8, line 20, after "means" insert --a.nd said rotating means--.

Column 8, line 61, oppoiste" should read --opposite.

SIGNED AND SEALED JUN 2 3.197

Amt:

"" mm 3. sum. .18.

Attestin Officer Commissioner 01' Paton"