US3451493A

US3451493A - Drilling apparatus and method

Info

Publication number: US3451493A
Application number: US626762A
Authority: US
Inventors: James C Storm
Original assignee: JAMES C STORM
Current assignee: JAMES C STORM
Priority date: 1967-03-29
Filing date: 1967-03-29
Publication date: 1969-06-24
Anticipated expiration: 1986-06-24
Also published as: GB1223433A; IL29683A; GB1223431A; GB1223432A

Abstract

1,223,433. Subaqueous drilling. J. C. STORM. 2 Jan., 1968 [29 March, 1967], No. 48256/69. Divided out of 1,223,431. Heading E1F. The subject matter of this Specification is identical with that described in Specification 1,223,431 but the claims relate to the drilling platform

Description

June 24, 1969 J. @STORM 3,451,493

DRILLING APPARATUS AND METHOD med March 29, 19e? sheet of s 4 /f f 44, ""'M Y 0 Y'/f/ l 3 3 l I I INVENTOR Jam es C. Sform A 7' TUR/VE Y June 24, 1969 J. c. STORM 3,451,493

DRILLING APPARATUS AND METHOD Filed march 29. 1967 sheet of 6 INVENTOR dames C. Sform f @EM ATTORNEY June24,1969 n QS-rom, v 3,451,493

DRILLING AP'ARATUS AND METHOD I med Marsh 29, 1967 sheet 3 of s INVENTOR James C. Sfar/n ATTORNEY Junez4,1969 www 3,451,493

DRILLING APPARATUS *'ND METHOD `lune 24, 1969 l`l, C. ST0RM- 3,451,493

i DRILLING AFPARATUS AND METHOD Filed March 29, 1967 sheet 5 of e u Q57- r QB..

//V YE N Tal? Jam es C. Sform JN M A TURA/E Y June 24, 1969 v J. @STORM 3,451,493

DRILLING APPARATUS AND METHOD Filed Maron 29, 1967 y sheet G of e .F/ /2 /6 77 f1 1,41 9 l P5 il 68 76 79 72 64 /67 @o o I 67 I NVIfN TOR James C. Sfar/n A TTORNEY 3,451,493 DRILLING APPARATUS AND METHOD James C. Storm, 823 S. Water St., Apt. 2A, Corpus Christi, Tex. 78401 Filed Mar. 29, 1967, Ser. No. 626,762 Int. Cl. E21b 15/02; E21c 11/00 U.S. Cl. 175-9 43 Claims ABSTRACT OF THE DISCLOSURE A tiltably mounted derrick permits directional or slant drilling at desired angles to the vertical, as well as vertical drilling. When directionally drilling, the derrick is tilted back over the draw works. A hydraulically operated collapsible frame is positioned in front of and aligned with the derrick, and pipe racks are located to one or both sides of the frame. In marine drilling, a platform having guide tubes is positioned on location, the directions of the guide tubes having been determined by the desired directions of the wells to be drilled. Thereafter, conductor casings are driven through the guide tubes, and drilling equipment mounted on the platform.

Background of the invention This invention relates to drilling apparatus and method adapted for the directional or vertical drilling of boreholes in the earth, on land or marine locations, for exploratory or producing operations. This invention also relates to a pipe handling device particularly adapted for use with the drilling apparatus herein disclosed, which IUnited States Patent O device permits rapid and easy handling of the drill pipe between a pipe rack and the derrick.

U.S. Patent 1,829,304 (1931) to Schroeder shows a barge-mounted tiltable derrick for drilling pile holes over the end of the barge. The derrick is tilted out beyond the end of the barge, and the draw works is in front of, and clear of, the tilted derrick. No pipe rack is shown, nor is there any disclosure of a pipe handling device between a pipe rack and the derrick. Due to the position of the draw works, it is clear that a pipe handling device could not be placed in front of, and clear of, the tilted derrick. This disclosed arrangement is quite impractical and unsuited for fast and economic handling of large quantities of pipe between a pipe rack and the derrick, and for minimal size of operating area when a plurality of slant wells are to be drilled.

U.S. Patent 2,792,198 (-1957) to Braun shows a truck or barge-mounted derrick which can be tilted from one angular position to another through the vertical. No pipe rack is shown, nor is there any disclosure of a pipe handling device between a pipe rack and the derrick. Due to the peculiar mounting of the derrick, a pipe handling device could not be placed in front of, and aligned with the plane of tilting of the derrick. This disclosed arrangement likewise is quite impractical and unsuited for fast and economic handling of large quantities of pipe between a pipe rack and the derrick, and for minimal size of operating area when a plurality of slant wells are to be drilled.

Summary of the invention One of the objects of this invention is to provide improved method and apparatus for vertical or directional drilling of boreholes in the earth, from land or marine locations.

Another of the objects of this invention is to provide an improved arrangement of pipe handling mechanism, pipe rack and derrick to permit fast and economic handling of pipe between the pipe rack and the derrick dur- 3,451,493 Patented June 24, 1969 ing various operations, particularly when the derrick is tilted.

Yet a further object of this invention is to provide an improved pipe handling mechanism for transporting drill. pipe between the pipe rack and the derrick.

Still another object of this invention is to provide derrick structure particularly adapted for drilling at an angle to the vertical.

Other and further objects of this invention will become apparent during the course of the following description and by reference to the accompanying drawings and the appended claims.

I have discovered that the foregoing objects can be attained by providing a drilling derrick and rotary tiltably mounted on a skid unit so as to overlie the draw works, the derrick when operating at an angle to the vertical being inclined backwardly and away from the central portion of the platform. A hydraulically operated, collapsible frame, pipe handling device is positioned in front of and aligned with the derrick. During marine drilling, the derrick, rotary, draw works and pipe handling device can be moved from one station to another on the platform, so that a number of directional wells may be drilled,

The foregoing arrangement permits rapid and economic handling of large quantities of pipe between the derrick and a pipe rack on one or both sides of the pipe handling device, pipe handling between stations is minimized, and the required deck area is also minimized.

In the method as practiced on marine locations, a platform having guide tubes extending therethrough is properly oriented and positioned on location, the directions of,

the guide tubes having been determined by the desired directions of the wells to be drilled. Thereafter, the conductor casings are driven through the guide tubes into the marine iloor, and the drilling equipment mounted on the platform. Drilling is then commenced through the conductor casings.

Brief description of the drawings Referring now to the drawings, in which like numerals represent like parts in the several views:

FIGURE l represents a view in elevation of the drilling derrick operating in tilted position on a platform in a marine location through one of sever-al conductor casings, the phantom lines showing the derrick in vertical position.

FIGURE 2 represents a view in elevation taken at right angles to FIGURE 1 with the pipe handling device omitted.

FIGURES 3a through 3i represent a series of diagrammatic views in plan of the operating deck of the platform of FIGURES [l and 2, showing a sequence of positions of the drilling derrick and the pipe handling device and pipe rack, for drilling a number of wells from the platform; specically, a vertical well and eight slanting or directional wells.

FIGURE 4 represents a view in front elevation of the derrick in vertical position, showing the swivel hooked to traveling block.

FIGURE 5 represents a view in side eleva-tion of the derrickftaken from the left of FIGURE 4, the traveling block yand swivel being omitted for purposes of clarity.

FIGURE 6 represents a section in elevation of the derrick, taken along the line 6-6 of FIGURE 4.

FIGURE 7 represents a section in plan taken along the line 7-7 of FIGURE 4 FIGURE 8 represents a view in side elevation, partially in section, of the derrick in tilted position and the pipe handling device with a length of pipe being lowered onto the pipe handling device.

FIGURE 9 represents Ia view in side elevation of the lower portion of the derrick showing a pipe supporting arm in operative position to supporta length of pipe which is free at Iits lower end, the phantom lines indicating the position of the pipe supporting Iarm when in inopperative position.

FIGURE represents a view in front elevation of the pipe supporting arm.

FIGURE 11 represents a partial View in front elevation ofthe derrick, generally similar to FIGURE 4, showing the pipe elevator hooked to the traveling block.

FIGURE 12 represents a view in side elevation of the pipe handling device `in fully extended position.

FIGURE 13 represents a view in side elevation of the pipe handling device in fully collapsed position.

FIGURE 14 represents a view in end elevation of the pipe handling device in extended position.

Description of preferred embodiment The preferred embodiment of the invention is shown in the accompanying drawings in a marine environment (although it will be understood that the invention is also contemplated las being applicable to non-marine environments).

Platform 1 for supporting the drilling equipment is seen as comprising tubular legs 2 receiving piles 3 driven into marine door y4, with suitable cross-bracing 5, some of which is shown.

Vertical members 6 are secured to legs 2 and extend upwardly therefrom to support upper deck 7, Below upper deck 7 are mounted second deck 8 and third deck 9, all above the surface of the water 10.

Guide tubes 11 are suitably mounted :to platform 1, each of said vguide tubes 11 corresponding in angle and direction to one of the boreholes or wells to be drilled in marine oor 4. Not all of the bracing S may be shown in :the drawings, to avoid confusion.

Extending through the guide tubes 11 and driven into the marine floor 4, are a number of conductor casings 11a. Each conductor casing 11a stands therefore at the desired angle and direction in which one borehole or well is to be drilled. This is a departure from the conventional practice of drilling vertically and then whipstocking to secure the desired directional borehole. In the arrangement herein disclosed, as seen in FIGURES 3a through 3i, there would be eight slanted conductor casings 11a and one ver-tical conductor casing 11a whereby nine wells can be drilled from this equipment. Only -a few of these conductor casings 11a and their respective yguide tubes 11 have been shown in the drawings, to avoid confusion.

Skid unit 12 is movably mounted 4to upper deck 7, and can be shifted from one station to ano-ther on the said upper deck 7, Skid unit 12 supports derrick 13, rotary 14 and draw works 15. Pipe handling device 16 'associated therewith can be supported partially on skid unit 12 and partially on ya stand 16a of the same height above upper deck 7 as skid unit 12, in front of derrick 13 and with one end thereof close to rotary 14 Ias shown, or can be supported completely in front of skid unit 12 and flat on upper deck 7.

Referring now 4to the derrick 13, it will be seen that the same comprises forward and rear main

structural elements

17 and 18, respectively, with bracing elements 19 extending between and secured to the rear rnain structural elements 18, and with bracing elements 20 extending between and secured to the forward and rear main

structural elements

17 and 18. The front face 21 of derrick 13 has, between forward main structural elements 17, a longitudinally extending guideway 22 bounded by inwardly facing parallel channels 2 3 providing trackways as will hereinafter be described, the said channels 23 being secured to their respective forward main structural elements 17 by means of braces 24, and to the bracing elements 19 rearwardly `thereof by means of Abraces 25.

Rear main structural elements 18 are, for the major portion of their lengths, generally parallel to forward main structural elements 17, The topmost and bottommost portions ci .rear main structural elements 1,8 are .4 inclined toward forward main structural elements 17 as best shown in FIGURES 5 and 6.

At the bottom of derrick 13, at -the junctures of forward and rear main

structural elements

1,7 and 18, are bearings 26 receiving axles or pivot pins 27,v the said axles or pivot pins 27 being rotatably supported in brackets 28 secured to skid unit 12. In this manner, derrick 13 is tiltably mounted to skid unit 12 and is capable of assuming -a vertical position or a slanting position of an angle to the vertical.

On each side of skid unit 12, a hydraulic ram 29 is pivotally supported on a leg 30 secured to the skid unit 12, and the top of the hydraulic ram 29 is pivotally connected -to one of the rear main structural elements of derrick 13. It will be apparent that when the hydraulic rams 29 are operated, by conventional hydraulic systems (not shown), the angle of the derrick 13 may be adjusted as desired. Various stiff legs or braces 31, 32 and 33, adjustable or non-adjustable depending upon whether the derrick 13 is to be operated -at one or several inclinations at a particular location, may be secured to the skid unit 12 and derrick 13 after the derrick 13 has been set at the desired inclination, to permit the hydraulic rams 29 to be relieved of pressure therein if desired` One of these braces 31 is shown in FIGURE 5, in which gure the derrick 13 has been indicated for convenience as vertical, and FIGURE 8 shows the three sets of br-

aces

31, 32 and 33 employed with the derrick 13 when in inclined position. Guy lines 34 extending between skid unit 12 and the top of derrick 13 are also used to brace the derrick 13 when in vertical or inclined position.

Crown block 35 is mounted to the top of derrick 13. Traveling block 36 is provided with Wheels 37 riding in channels 23, whereby -motion of -said traveling block 36 is constrained to longitudinal movement relative to derrick 13 within longitudinal guideway 22 regardless of the inclination of said derrick 13. 4Movement of traveling block 36 within longitudinal guideway 22 is controlled by means of lines 38 passing over crown block 35 and connected to a drum on draw works 15. Pivotally secured to the .bottom of traveling block 36 are hook eyes 39 for a purpose which will hereinafter be described.

The conventional swivel 40 employed in rotary drilling operations is provided with wheels 41 adapted to ride in channels 23, whereby motion of said swivel 40 is constrained to longitudinal movement relative to derrick 13 within longitudinal guideway 22 regardless of the inclination of said derrick 13. Swivel 40 is provided with hooks 42 adapted to be removably engaged in hook eyes 39 of traveling block 36. The conventional mud line 43 communicates between a mud tank (not shown) and the swivel 40 in the well-known manner. Kelly 44 is connected to swivel 40 and is adapted to extend through drive bushings 45 in rotary 14.

It will be noted that portions of the front flanges of channels 23 have been removed to provide lopenings 100 in the said channels 23. These openings are of length somewhat greater than the -diameters of wheels 41, and are at an elevation such that, when swivel 40 has been raised to place wheels 41 adjacent said openings 100, the bottom of Kelly 44 will clear the operating area on the skid unit 12. Along one side of longitudinally eX- tending guideway 22, a pair of lugs 101 is secured to braces 24, and these lugs 101 are perforated to receive a tubular element 102, the said tubular element 102 being fixed to the said lugs 101. Tubular collar 103 is loosely mounted concentrically about tubular element 102, between lugs 101, and is therefore free to rotate but is fixed longitudinally. Arm 104 is rigidly secured to tubular collar 103, and is braced thereto by means of brace 105. The end of arm 104 has an upstanding pin element 106. Bracket 107, secured to swivel 40, is provided with one or more perforations 108 adapted to receive pin element 106. The elevation 4of arm 104 and pin element 106, the elevation of openings 100, the length of openings 100, and the length of arm 104 are so related that, when wheels 41 have been raised adjacent the upper portions of openings 100, arm 104 can be rotated from inoperative position (as shown in FIGURE 4) to a position just under bracket 107 with pin element 106 below a perforation 108, and when swivel 40 has been lowered to seat perforation 108 around pin element 106 and rest bracket 107 on arm 104, wheels 41 will clear the bottoms of openings 100.

Thus, when it is desired to remove swivel 40 and Kelly 44 from derrick 13, traveling block 36 is raised to bring wheels 41 adjacent the upper portions of openings 100. Arm 104 is swung from inoperative position to a position 'beneath lbracket 107, with pin element 106 registering with a perforation 108, and traveling .block 36 is lowered so that bracket 107 rests on arm 104 with pin element 106 in perforation 108. The weight of the swivel 40 and Kelly 44 now being supported on arm 104, hooks 42 are then disengaged from hook eyes 39. Arm 104 is swung away from longitudinally extending guideway 22, carrying with it swivel 40 and Kelly 44 to one side of the derrick 13 where the same may be stored until again needed.

When it is desired to reintroduce swivel 40 and Kelly 44, the operations above described are reversed.

Any means may be employed to rotate arm 104 and tubular collar 103 -about tubular element 102. In the preferred embodiment, a hydraulic cylinder is employed. This hydraulic cylinder has been omitted from the drawings to avoid excessive and unnecessary detail which would obfuscate the said drawings.

A pipe elevator 46 with bowl 47 adapted to receive drill -pipe 48 and containing conventional slips (not shown) to support the drill pipe 48 from the said pipe elevator 46, is provided with wheels 49 adapted to ride in channels 23, whereby motion -of said pipe elevator 46 is constrained to longitudinal movement relative to derrick 13 within longitudinal guideway 22 regardless of the inclination of said derrick 13. Pipe elevator 46 is provided with hooks 50 adapted to be removably engaged in hook eyes 39 of traveling block 36.

Rotary 14, indicated diagrammatically `only in the several figures, is mounted for support in a base 14a. Base 14a, also indicated only diagrammatically, is pivotally mounted in brackets 51 secured to skid unit 12. It is to be particularly noted that the axis 52 about which the lbase 14a (and therefore rotary 14) is mounted is the same axis about which derrick 13 is mounted to skid unit 12, and that axis 52 intersects the longitudinal (i.e., vertical) axis of the opening or operating aperture of rotary 14. Because of this geometrical relationship, the angular relationship of the derrick 13 with skid unit 12 can be lduplicated by the angular relationship of rotary 14 with skid unit 12, and the `opening in the said rotary 14 can therefore always register with the drilling axis of the derrick 13, and thus be in proper alignment to receive Kelly 44 or drill pipe 48. Rotary 14 is driven from a power takeolf of draw works 1'5 in a conventional manner. It will be understood that skid unit 12 is provided with opening 53 lbetween brackets 51 sufficiently large to permit the desired tilting of the base 14a. As shown in some of the figures, a guard 54 is mounted to skid unit 12 between the rotary 1-4 and pipe handling device 1.6 for reasons of safety.

A baille 55 is secured t-o bracing elements 19 of derrick 13, as `shown particularly in FIGURES 4 and 7, to prevent damage to draw Works by falling tools when derrick 13 is inclined over the said draw works 15.

It will be recognized that there are times, when derrick 13 is tilted, that sections of `drill pipe 48, or even Kelly 44, will be supported at their upper end-s only. Due to the action of gravity, the said sections of drill pipe 48 or the Kelly 44 will tend to assume a vertical position and, in so doing, may damage, or 'be damaged by, portions of the derrick structure, or might otherwise interfere with operations. To maintain these sections of drill pipe 48 or the Kelly 44 in alignment with derrick 13, regardless of the degree of tilt, supporting arm 56 is provided. As shown in FIGURES 9 and 10, one end of supporting arm 56 is pivotally mounted by lmeans of pin 57 passing therethrough and through brackets 58, to strap 59 fastened across the rear of derrick 13 at a suitable elevation adjacent the lower end thereof. The free end of -supporting arm 56 is provided with a fork 60 adapted to cradle drill pipe 48 or Kelly 44. A hydraulic ram 61 i-s pivotally mounted at one end t-o the rear of the derrick structure below brackets 58, as shown in FIGURE 9, and the other end is pivotally mounted to supporting arm 56, immediately behind fork `60. It will lbe seen that supporting arm 56 can be raised from the inoperative position shown in phantom in FIGURE 9 to the operative position therein shown in solid lines by pressurizing the hydraulic ram 61.

Derrick 13 is provided with a folding Walkway 62 pivotally mounted to forward main structural elements 17 and maintained in position by guy wires 63 fastened between the unhinged end of folding walkway 62 and the top of derrick 13.

Pipe handling device 16 comprises a base 64 wide enough for stability and resting partially on skid unit 12 with one end close to guard 54, and partially on stand 16a having a top surface even with the top surface of skid unit 12, with V-shaped cradle 65, and parallel links 66 on each side of base 64 and cradle 65 pivotally mounted to the said base 64 by means of pins 67, and to the said cradle 65 by means 0f pins 68. yIt will be seen that cradle 65 is capable of being raised upwardly and simultaneously shifted laterally towards rotary 14, and vice versa, as shown by the arrows in FIGURES 12 and 13. Approximately in the center of pipe handling device 16, a hydraulic ram 69 is interposed between base 64 and cradle 65. The hydraulic cylinder 70 of ram 69 is pivotally mounted to base 64 :by means of pin 71 passing through brackets 72 secured to base 64 and passing through ear 73 on the cylinder 70. The piston rod 74 of ram 69 is pivotally mounted to cradle l65 by means of pin 75 passing through an aperture in the piston rod 74 and through brackets 76 secured to the cradle 65. The longitudinal axis of ram 69, when pipe handling device 16 is fully collapsed as shown in FIGURE 13, is preferably at a slight angle to the horizontal, to minimize the force initially required t0 open and extend the pipe handling device. Pipe supports 77 are mounted in cradle 65 on rollers 78, whereby the said pipe supports 77 are freely movable in said cradle 65 longitudinally of the pipe handling device 16. It will be particularly noted that the longitudinal axis of pipe handling device 16 (viz., the center of cradle 65) is in line with the plane in which the longitudinal centerline of derrick 13 is rotated as the said derrick is tilted from the vertical. Therefore, regardless of the angle at which derrick 13 is set for drilling, drill pipe 48 can always be removed from, or passed to the said derrick 13 in a straight line.

Hydraulic lines

79 and 80 communicate between both ends of hydraulic cylinder 70 and a remote source of pressurized hydraulic fluid (not shown) and are controlled by a remotely situated control valve (not shown) whereby the degree of extension of hydraulic ram 69, and hence the elevation of cradle 65, can be closely controlled and stopped at any desired point.

Means to rack pipe 48 may be positioned to either or 'both sides of pipe handling device. As shown in FIGURES 3a through 3i, the pipe rack, indicated diagrammatically as 81, in the particular arrangement herein disclosed, is located to one side only of the pipe handling device.

The operation of the preferred embodiment of the invention will now be described.

It will be assumed that one vertical well and eight slanted or directional wells are to be drilled in a marine environment. (It will be understood, of course, that more 7 than eight directional wells can be drilled.) Platform 1, with guide tubes 11, is properly oriented and established on location.

It will be noted that the tops of guide tubes 11 terminate above third deck 9 and below second deck 8, and that there are flared mouths 82 on top of guide tubes 11 above third deck 9. Conductor casings 11a are now inserted into guide tubes 11, the flared mouths 82 facilitating entry thereof, and the conductor casings 11a are driven into marine floor 4 as shown. Second deck 8 is intended to support such equipment as mud pumps, mud tanks, water tanks and the like (not shown), and this equipment may now be placed on said second deck 8. The conventional Christmas trees (not shown) for well control are intended to be installed and maintained from the level of third deck 9 (or as desired by the operator) upon completion of wells.

Drilling equipment, comprising derrick 13, rotary 14 and draw Works mounted on skid unit 12, pipe handling device 16, and crane 83 are now placed on upper deck 7. Other auxiliary equipment (not shown) such as :bulk cement storage tanks, a logging unit, fuel tanks and the like are also placed on upper deck 7.

The actual drilling operations are now ready to take place. :It will be noted that upper deck 7 has a number of openings therethrough, each aligned with the longitudinal axis of one of the conductor casings 11a. These openings are indicated diagrammatically by the letters A, B, C, D, E, F, G, H and I in FIGURES 3a through 3i. The plan of operation is to drill through the central opening A and the vertical conductor casing 11a first, as shown in FIG- URE 3a, derrick 13 being7 vertical of course. Skid unit 12 is shifted to the proper position to align the opening in rotary 14 over opening A, and pipe handling device 16 and stand 16a are set up in front of, and aligned with derrick 13. In FIGURE 3a, 84 represents the longitudinal center line of pipe handling device 16, and this line passes through the center of the opening in rotary 14 and through the center of derrick 13 (i.e., through the drilling axis of derrick 13). The numeral 85 represents an axis of the opening in rotary 14 perpendicular to line 84. Pipe rack 81 is set up to one side of pipe handling device 16. The rectangle 86 represents diagrammatically the .horizontal extent of skid unit 12, and the numeral 87 represents diagrammatically the area required for operations with pipe handling device 16 and pipe rack 81. In the drilling operation, pipe 48 from pipe rack 81 is readily shifted to pipe supports 77 of pipe handling device 16 and rolled toward derrick 13 Where it is added to the upper string when making hole. Conversely, pipe 48 is readily moved from the derrick 13 to pipe supports 77 of pipe handling device 16 and rolled toward pipe rack 81, when making a trip (i.e., when removing and breaking down the drill pipe string to replace a drill bit). The actual operations at the derrick will be described further on. After completion of drilling operations through opening A, the Christmas tree is installed from the level of third deck 9.

The next well to be drilled in sequence is that through conductor casing 11a registering with opening B. Skid unit 12 is shifted to the position shown in FIGURE 3b, with centerlines 84 and 85' aligned with the center of opening B. Derrick 13 and base 14a supporting rotary 14 are tilted to the proper angle to align the drilling axis of derrick 13 and the longitudinal axis of the operating aperture of rotary 14 with the longitudinal axis of the corresponding conductor casing 11a, it being noted that the draw works 15 is adjacent the edge of upper deck 7 and that derrick 13 is inclined backwardly and away from the center of upper deck 7. -It will also be noted that pipe rack 81 is approximately in the center of upper deck 7. After pipe handling device 16 and 16a have been placed in front of derrick 13, and pipe 48 stored on pipe rack 81, the drilling operation proceeds, the string of drill pipe 48 being made up and broken down as required. Upon completion of the well, and installation of the Christmas tree at the level of third deck 9, the skid unit 12 is positioned over opening C as shown in FIGURE 3c, and the operations described in connection with FIGURE 3b are repeated. The sequence of drilling proceeds clockwise through the remainder of the openings D through I, as shown in FIGURES 3d through 3i. It will be particularly noted that in drilling the slanted or directional wells through openings B through I, as shown in FIGURES 3b through 3i, the pipe rack 81 is always approximately in the center of upper deck 7, and that in setting up the drill pipe 48 after completion of one slanted well and prior to drilling the next slanted well, substantially only the alignment of the pipe 48 must be changed, with a slight shifting or translation of the pipe 48. When it is realized that thousands of feet of pipe 48 are ordinarily used in drilling a. well, and that all of this pipe 48 may be on pipe rack 81 after completion of one well and prior to starting drilling of the next well, it should be appreciated that this minimal handling of pipe between drilling stations affords a very considerable saving in the drilling operation. It should also be apparent, from an inspection of FIGURES 3a through 3i that the particular arrangement of drilling equipment, ywith draw works 15 outboard derrick 13, with derrick 13 slanted backwardly and away from the center of upper deck 7, and with the pipe rack 81 always approximately in the center of upper deck 7 (except when drilling through opening A), the area required for upper deck 7 is minimal. This, of course, affords a considerable saving in construction costs of platform 1.

In the actual drilling operating at a particular drilling station on upper deck 7, swivel 40 is hooked to traveling block 36, and drilling proceeds in the customary manner.

Let it now be assumed that it becomes necessary to replace the drill bit at the bottom of the drill string in the course of drilling a directional or slanted well. This means that all of the drill pipe 48 must lbe removed from the hole. The traveling block 36 is raised to bring wheels 41 of swivel 40 adjacent the upper portion of openings 100, and arm 104 is swung under bracket 107 to register pin element 106 with a perforation 108. Traveling block 36 is lowered slightly to transfer the weight of the swivel 40 and Kelly 44 to arm 104, swivel 40 is unhooked from traveling block 36, and arm 104 is swung to the side of the derrick 13, carrying swivel 40 and Kelly 44 away, all as hereinbefore described. Traveling block 36 is then lowered, and pipe elevator 45 hooked thereto, the wheels 49 being introduced into channels 23 from the bottoms thereof. In this connection, it will be observed that channels 23 are ared at their bottoms to facilitate entry. Pipe elevator 45, now being connected to traveling block 36, is placed over the top of the drill string in the well, slips in the pipe elevator 45 are set and the pipe elevator 45 is raised to Withdraw a portion of the drill string. Usually, several sections of connected pipe 48 are thus raised above rotary 14, and the bottom end thereof unscrewed from the remaining drill string which is held suspended -by means of slips in the customary manner. In this regard, it should be noted that the top of the drill string must be centered in the rotary opening in order that the slips can be properly set. In slant or directional drilling, the top of the drill string will not lbe centered but will be adjacent the low side of the rotary opening, and must therefore be pushed to the center of the rotary opening. This can be done by means of a hydraulic cylinder mounted in the skid unit 12 below the rotary 14, the end of the piston rod having a roller adapted to contact and push the top of the drill string to a central position in the rotary opening when the hydraulic cylinder is pressurized. Prior to the operation of disconnecting the sections of pipe 48 from the remaining drill string, supporting arm 56 is extended so that fork 60 engages the lower portion of the sections of pipe 48, thus preventing the same from swinging to the vertical when disconnection is complete. In FIGURE 8, I show three connected sections of drill pipe 48 being handled as one piece (called a thribble). Pipe handling device 16 is in fully extended position, and pipe supports 77 are all adjacent rotary 14. The bottom of the thribble is pushed away from derrick 13, if desired with the aid of a hydraulic cylinder (not shown) interposed between the derrick 13 and the bottom of the thribble, and is placed on that pipe support 77 furthest from rotary 14, and pipe elevator 46 is lowered (see FIGURE 8). Derrick 13 being in tilted position, the bottom of the thribble will move to the right in FIGURE 8, supported on pipe support 77, and pipe elevator 46 is lowered further until the upper portion of the thribble rests on a pipe support 77. In this operation, it may be necessary to let pipe elevator 46 leave channels 23 temporarily to bed the upper portion of the thribble on the pipe support 77. The thribble, now being in horizontal position on pipe supports 77, is moved away from derrick 13 toward pipe rack 81 and, simultaneously, hydraulic ram 69 may be operated to collapse pipe handling device 16 to the extent that the thribble is on the approximate level of the said pipe rack 81. The thribble may now be lifted from pipe supports 77 and shifted laterally to the pipe rack 81. Pipe elevator 46 is again placed over the top of the drill string and this operation repeated until the entire drill string has been broken down into sections (thrib'bles, as herein disclosed) and racked on pipe rack 81.

Let it now be assumed that the drill bit Ihas been replaced. It is now required to reinstall the string of drill pipe 48 inthe well before further drilling operations are commenced. The procedure 4outlined in the preceding paragraph is reversed, the -thribbles being shifted laterally from pipe rack 81 to pipe supports 77 on collapsed pipe handling device 16, :and 'then moved toward derrick 13 while pipe 'handling device 16 is being extended. Pipe elevator 46 is lowered and connected lto one end of the ithribble l(if necessary, being temporarily :removed from channels 23) and raised, drawing Ithe thribble of drill pipe 48 upwardly into the derrick 13. Supporting 'arm 56 is extended to hold the thribble on lthe drilling axis of the derrick 13 until ythe lower end of the -thribble is connected to the drill string lheld suspended in ythe well. Pipe elevator 46 is lowered, lowering the thribble and connected drill string, and the same is resuspended in the conventional manner. Pipe elevator 46 is disengaged from the drill string, and this procedure is repeated until the drill string 'has been completely made up.

It will be understood that, when derrick 13 is in vertical position, drilling a vertical well, the drill pipe 48 is racked upright in a rconventional manner, there being no necessity to lay the drill pipe 48 ldown :as is required for slant or directional wells as hereinbefore described.

Drilling operations are now ready to be resumed. Traveling block 36 is lowered .to permit the wheels 49 of pipe elevator 46 to clear the bottoms of channels 23. Pipe elevator 46 is then unhooked from traveling block 36 and stored in a :convenient place. Traveling block 36 is then raised to la position above openings 100. Arm 104, carrying the swivel 40, kelly 44 and drive 'bushing 45, is swung toward the longitudinally extending g-uideway 22, and wheels `41 are introduced through openings 100. Hooks 42 are engaged in lhook eyes 39, ythe elevation of traveling block 36 being suitably adjusted Ifor -this purpose. Traveling block 36 is 'then raised to support fthe weight of tbe swivel 40, kelly 44 and drive bushing `45 and to yfree bracket 107 from pin element 106. Arm 104 is then swung away to the side of the derrick 13. Connection of the kelly 44 to the drill pipe 48 is made and drilling operations can begin as hereinbefore described.

I claim:

1. Well drilling apparatus comprising:

(a) a vertical derrick structure 13),

(b) a pair of horizontally spaced, parallel channel members (23) secured to said derrick struct-ure (13),

10 said channel member (23) 'being larranged with their -anges projecting toward each other and defining a longitudinal guideway (22) in the derrick structure (13), each ot said channel m'am'bers (23) providing :a track,

(c) a traveling block (36) in said longitudinal guide- Way (22),

(d) a pair of wheel means (37), one on each side of said traveling block (36), each o-f said wheel means (37) being positioned in the track provided by one of said channel members (23), whereby motion of said traveling block (36) is constrained to movement longitudinally of said derrick structure (13) in the longitudinal guideway (22),

(e) means (15, 3S, 38) to raise or selectively to lower said traveling block (36),

(f) a rotary (14) adjacent the bottom or said derrick structure (13), .said rotary (14) having a vertical operating aperture therethrough, the longitudinal axis of Said aperture substantially registering with It-he center of the longit-udinal guideway (22),

(1g) .a swivel (40) adapted to be removably secured to said traveling block (36), said swivel (40) being further `adapted to support a kelly (44) over the aperture in said rotary (114),

('h) a pair of wheel means (41), one on each side of said swivel ('40), each of said wheel means (41) being adapted to be positioned in the track provided by one of said channel members 1(23), whereby m0- tion of said swivel (40) i-s constrained lto movement longitudinally of said derrick structure (13) in the longitudinal guideway (22),

(i) a pipe elevator (46) vadapted Ito be removably secured to said traveling block (36), said pipe elevator y(46) being f-urtiher adapted to support drill pipe (48) over the aperture in said rotary (114),

(j) 'a pa-ir of wheel means (49), one on each side of said pipe elevator (46), each of said wheel means (49) being adapted to be positioned in the track provided by one of said channel members (23), `whereby motion of said pipe elevator (46) -is constrained -to movement longitudin-ally off said derrick structure (13) in lthe longitudinal guideway (22).

2. Apparatus 'as in claim 1, further comprising:

(k) said channel members (23) being provided with openings between the upper and lower ends thereof,

(l) 'the wheel means (41) of said swivel (40) being 'adapted to be inserted in or selectively lremoved from 'the tracks provided by the channel members (23) through the openings 100) between the upper and lower ends of sai-d channel members (23),

(rn) the bottom portions of said channel members 23) being open,

(n) the wheel means ('49) of said pipe elevator (46) being adapted to be inserted in or selectively removed from the tracks provided by said channel members (23) through the open bottoms of said channel members (23).

3. Apparatus as in claim 1, further comprising:

(k) said channel members (23) being provided with openings (100) between the upper and lower ends thereof,

(l) the wheel means (41) of said swivel (40) being adapted to be inserted in or selectively removed from the tracks provided by the channel members (23) lthrough the openings (100) between :the upper and lower ends of said channel members (23),

(m) an arm (104) pivotally mounted to said derrick structure (13) to one side of said longitudinal g-uidelway (22) adjacent said openings `(100), said 'arm (104) being :adapted to be rotated towards said longitudinal guideway (22) to supporting relation with said 4swivel (40) and thence a'way from said longitudinal guideway (22) carrying ltherewith said swivel (40) or selectively towards said longitudinal guideway (22) carryin-g ltherewith said swivel (40) and thence away from said longitudinal guideway (22).

4. Apparatus as in claim 1, further comprising:

(k) pipe handling means (16) adapted to move drill pipe (48) towards or selectively away from said derrick structure(13) in a direction parallel to the longitudinal axis of the drill pipe (48;) being moved and intersecting the longitudinal axis of said longitudinal guideway (22).

5. Apparatus as in claim 4, said pipe handling means (16) comprising:

(l) a base (64),

(m) an elongated cradle (65) adapted to support drill pipe (48) with the longitudinal axis of said drill pipe (48) intersecting the longitudinal axis of said longitudinal guideway (22),

(n) linkage means (66) connecting said cradle (65) and said base (64) and constraining movement of said cradle (65 to an arc parallel with the longitudinal axis of said drill pipe (48),

(o) motor means (69) operatively interposed between said base (64) and said cradle (65) to move said cradle (65) along said arc to an extended position upwardly relative to said base (64) and toward said derrick structure (13) or selectively to a collapsed position downwardly relative to said base (64) and away from said derrick structure (13).

6. Apparatus as in claim 5, said motor means (.69)

comprising:

(p) a hydraulic ram interposed between said cradle (65) and said base (64) approximately in the center of the length of said pipe handling means (16), the longitudinal axis of said hydraulic ram being inclined in a vertical plane at an angle to the horizontal at all times.

7. Apparatus as in claim 6, said pipe handling means (16) further comprising:

(q) pipe support means (77),

(r) roller means (78) mounting said pipe support means (77) in said cradle (65).

8. Well drilling apparatus comprising:

(a) base means (12),

(b) a derrick structure (13) pivotally mounted to said base means (12) for rotation in a vertical plane about a horizontal axis (52) (c) means (29) to adjust the derrick structure (13) to a vertical position or selectively to an inclined position,

(d) a rotary (14),

(e) means (14a) pivotally mounting said rotary (14) to said base means (12) ifor rotation in a vertical plane about the same horizontal axis (52) as the derrick structure (13), the rotary (14) having an operating aperture therethrough, the axis (52) intersecting the longitudinal axis of the operating aperture,

(f) pipe handling means (16) adapted to move drill pipe (48) towards or selectively away from said der-rick structure (13) in a direction parallel to the longitudinal axis of the drill pipe (48) being moved and intersecting the longitudinal axis of the operating aperture ofthe rotary (14).

9. Apparatus as in claim 8, said pipe handling means (16) comprising:

(g) a base (64),

(h) an elongated cradle (65) adapted to support drill pipe (48) with the longitudinal axis of said drill pipe (48) intersecting the longitudinal axis of the operating aperture of the lrotary (14),

(i) linkagerneans (66) connecting said cradle (65) and said base (64) and constraining movement of said cradle to an arc parallel with the longitudinal axis of said drill pipe (48),

(j) motor means (69) operatively interposed between said base (64) and said cradle (65) to move said cradle (65) along said arc to an extended position upwardly relative to said base (64) and toward said derrick structure (13) or selectively to a collapsed position downwardly relative to said base (64) and away from said derrick structure (13).

10. Apparatus as in claim 9, said motor means (69) comprising:

(k) a hydraulic ram interposed between said cradle (65) and said base (64) approximately in the center of the length of said pipe handling means (16), the longitudinal axis of said hydraulic ram being inclined in avertical plane at an angle to the horizontal at all times.

11. Apparatus as in claim 10, said pipe handling means (16) `further comprising:

(l) pipe support means ('77),

(m) roller means (78) mounting said pipe support means (77) in said cradle (65).

12. Well drilling apparatus comprising:

(a) base means (12),

(d) arotary (14),

(e) means (14a) pivotally mounting said rotary (14) to said base means (12) for rotation in a vertical plane about the same horizontal axis (52) as the derrick structure (13), the rotary (14) having an operating aperture therethrough, the axis (52) intersecting the longitudinal axis of the operating aperture,

(f) a supporting arm (56) having a supporting end (60), said supporting arm (56) being mounted to said derrrick structure (13) above the rotary (14),

(g) operating means (61) to extend the supporting end (60) of said supporting arm (56) to a position adjacent the longitudinal axis of the operating aperture of the rotary (14) or selectively to retract the supporting end (60) of said supporting arm (56) away from said position.

13. Apparatus as in claim 12, further comprising:

(h) that end of supporting arm (56) opposite the supporting end (60) being pivotally mounted to said derrick structure 13),

(i) the operating means 61) being interposed between the supporting end (60) of supporting arm (56) and the derrick structure (13).

14. Well drilling apparatus comprising:

(a) base means (12),

(b) a derrick structure (13) pivotally mounted to said base means (12) for rotation in a vertical plane about a horizontal axis (52),

(c) means (29) to adjust the derrick structure (13) to a vertical position or selectively to an inclined position,

(d) a pair of horizontally spaced, parallel channel members (23) secured to said derrick structure (13), said channel members (23) being arranged with their flanges projecting toward each other and defining a longitudinal guideway (22) in the derrick structure (13), each of said channel members (23) providing a track,

(e) a traveling block (36) in said longitudinal guide- WaY (22),

(f) a pair of wheels means (37), one on each side of said traveling block (36), each of said wheel means (37) being positioned in the track provided by one of said channel members (23), whereby motion of said traveling block (36) is constrained to move- 13 ment longitudinally of said derrick structure (13), in the longitudinal guideway (22),

(g) means (15, 35, 38) to raise or selectively to lower said traveling block (36),

(h) a rotary (14),

(i) means (14a) pivotally mounting said rotary (14) to said base means (12) for rotation in a vertical plane about the same horizontal axis (52) as the derrick structure (13), said rotary (14) having an operating aperture therethrough, the longitudinal axis of the said operating aperture substantially registering with the center of the longitudinal guideway (22), said operating aperture being adapted to receive a kelly (44) or selectively a drill pipe (48), the axis (52) intersecting the longitudinal axis of the operating aperture,

(j) a swivel (40) adapted to be removably secured to said traveling block (36) said swivel (40) being further adapted to support the upper end of a kelly (44) extending through the operating aperture of the rotary (14),

(k) a pair of wheel means (41), one on each side of said swivel (40), each of said wheel means (41) being adapted to be positioned in the track provided by one of said channel members (23), whereby motion of said swivel (40) is constrained to movement longitudinally of said derrick structure (13) in the longitudinal guideway (22),

(l) a pipe elevator (46) adapted to be removably secured to said traveling block (36), said pipe elevator (46) being further adapted to support the upper end of drill pipe (4S),

(m) a pair of wheel means (49), one on each side of said pipe elevator (46), each of said Wheel means (49) being adapted to be positioned in the track provided by one of said channel members (23), whereby motion of said pipe elevator (46) is constrained to movement longitudinally of said derrick structure (13) in the longitudinal guideway (22).

15. Apparatus as in claim 14, further comprising:

(n) a supporting arm (56) having a supporting end 60) adapted to engage said kelly (44) or selectively said drill pipe (48), said supporting arm (56) being mounted to said derrick structure (13) above the rotary (14),

(o) operating means (61) to extend the supporting end (60) of said supporting arm (56) to a position adjacent the longitudinal axis of the operating aperture of the rotary 14) thereby to support said kelly (44) or said drill pipe (48) or selectively to retract the supporting end (60) of said supporting arm (56) away from said position.

16. Apparatus as in claim 14, further comprising:

(o) operating means (61) to extend the supporting end (60) of said supporting arm (56) to a position adjacent the longitudinal axis of the operating aperture of the rotary (14) thereby to support said kelly (44) or said drill pipe (48) or selectively to retract the supporting end (60) of said supporting arm (56) away from said position,

(p) that end of supporting arm (56) opposite the supporting end (60) being pivotally mounted to said derrick structure (13),

(q) the operating means (61) being interposed between the supporting end (60) of supporting arm (56) and the derrick structure (13).

17. Apparatus as in claim 14, further comprising:

(n) said channel members (23) being provided with openings (100) between the upper and lower ends thereof,

(o) the wheel means (41) of said swivel (40) being adapted to be inserted in or selectively removed from the tracks provided by the channel members (23) through the openings between the upper and lower ends of said channel members (23),

(p) the bottom portions of said channel members (23) being open,

(q) the wheel means (49) of said pipe elevator (46) being adapted to be inserted in or selectively removed from the tracks provided by said channel members (23) through the open bottoms of said channel members (23).

18. Apparatus as in claim 14, further comprising:

(o) the wheel means (41) of said swivel (40) being adapted to be inserted in or selectively removed from the tracks provided by the channel members (23) through the openings (100) between the upper and lower ends of said channel members (23),

(p) an arm (104) pivotally mounted to said derrick structure 13) to one side of said longitudinal guideway (22) adjacent said openings (100), said arm (104) being adapted to be rotated towards said longitudinal guideway (22) to supporting relation with said swivel (40) and thence away from said longitudinal guideway (22) carrying therewith said swivel (40) or selectively towards said longitudinal guideway (22) carrying therewith said swivel (40) and thence away from said longitudinal guideway (22).

19. Apparatus as in claim 14, further comprising:

(n) pipe handling means (16) adapted to move drill pipe (48) towards or selectively away from said derrick structure 13) in a direction parallel to the longitudinal axis of the drill pipe (48) being moved and intersecting the longitudinal axis of said longitudinal guideway (22).

20. Apparatus as in claim 19, said pipe handlin-g means (16) comprising:

(o) a base (64),

(p) an elongated cradle (65) adapted to support drill pipe (48) with the longitudinal axis of said drill pipe (48) intersecting the longitudinal axis of said longitudinal guideway (22),

(q) linkage means (66) connecting said cradle (65) and said base (64) and constraining movement of said cradle (65) to an arc parallel with the longitudinal axis of the drill pipe (48) being moved,

(r) motor means (69) operatively interposed between said base (64) and said cradle (65) to move said cradle (65) along said arc to an extended position upwardly relative to said base (64) and toward said derrick structure (13) or selectively to a collapsed position downwardly relative to said base (64) and away from said derrick structure 13).

21. Apparatus as in claim 20, said motor means (69) comprising:

(s) a hydraulic ram interposed between said cradle (65) and said base (64) approximately in the center of the length of said pipe handling means (16), the longitudinal axis of said hydraulic ram being inclined in a vertical plane at an angle to the horizontal at all times.

22. Apparatus as in claim 21, said pipe handling means further comprising:

(d) motor means (69) operatively interposed between said base (64) and said cradle (65) to move said cradle (65) along said arc to an extended position upwardly relative to said base (64) and toward one end of said pipe handling apparatus (16) or selectively to a collapsed position downwardly relative to said base (64) and away from said end of said pipe handling apparatus (16).

24. Apparatus as in claim 23, said motor means (69) comprising:

(e) a hydraulic ram interposed between said cradle (65) and said base (64) approximately in the center of the length of said pipe handling apparatus (16), the longitudinal axis of said hydraulic ram being inclined in a Vertical plane at an angle to the horizontal at all times.

25. Apparatus as in claim 24, further comprising:

(f) pipe support means (77),

(g) roller means (78) mounting said pipe support means (77) in said cradle (65).

26. Pipe handling apparatus comprising:

(a) an elongated base (64),

(b) an elongated V-shaped cradle (65) over said base (64),

(c) linkage means (66) connecting said cradle (65) and said base (64) and constraining movement of said cradle (65 relative to said base (64) to an are,

(d) a hydraulic ram (69) pivotally mounted at one end to said cradle (65 and pivotally mounted at the other end to said base (64) to move said cradle (65 along said arc to an extended position upwardly relative to said base (64) and toward one end of said pipe handling apparatus (16) or selectively to a collapsed position downwardly relative to said base (64) and away from said end of said pipe handling apparatus (16),

(e) said hydraulic ram (69) being positioned approximately in the center of the length of said pipe handling apparatus (16), the longitudinal axis of said hydraulic ram (69) being inclined in a vertical plane at an angle to the horizontal at all times,

(f) V-shaped pipe support means (77 (g) roller means (78) interposed between the sides of the V-shaped pipe support means (77) and the sides of the V-shaped cradle (65), thereby rollably mounted said pipe support means (77 in said cradle (65).

27. Apparatus for drilling a plurality of wells, cornprising: t

(a) an operating platform (7),

(lb) a plurality of openings (B, C, D, E, F, G, H, I) in said operating platform (7 each opening constituting a drilling station, said openings being spaced around the perimeter of the operating platform (7),

(c) a derrick structure (13) movably mounted on the operating platform (7) and adapted to be shifted from one drilling station to another drilling station to drill through said openings in sequence,

(d) a pipe rack (81) associated with said derrick structure (13) and mounted in the central portion of said operating platform (7) inboard of said derrick structure (13) when said derrick structure (13) is drilling through any of said openings (B, C, D, E, F,G,H,I

(e) a draw works (15 for operating said derrick structure (13), said draw works (15) being movably mounted on said operating platform (7 and adapted to be shifted from one drilling station to another drilling station, said draw Works (15) being located outboard of said derrick structure (13) when said derrick structure (13) is drilling through any of said openings (B, C, D, E, F, G, H, I).

28. Apparatus as in claim 27, said wells being inclined at an angle to the horizontal, said apparatus further comprising:

16 (f) said derrick structure (13) being tilted backwardly and away from the central portion of the operating platform (7 so that the said derrick structure (13) overlies the draw works (15 when the derrick structure (13) is drilling through an opening (B, C, D, E, F, G, H, I) corresponding to an inclined well. 29. The method of drilling at a marine site a plurality of slanting wells in the marine bottom, said wells having a predetermined inclination to the horizontal and having 10 a predetermined orientation with respect to each other,

said method comprising:

(a) fabricating a platform (1) with a plurality of guide tubes (11), each guide tube (11) correspondug in inclination to the horizontal and orientation with one of said wells to be drilled,

(b) mounting a derrick (13) having a drilling axis on said platform (1),

(c) transporting said platform (1) to the marino site,

(d) orienting and establishing said platform (1) at the marine site so that the axis of each guide tube (11) registers with the axis of one of said wells to be drilled,

(e) driving conductor casings (11a) through the guide tubes (11) into the marine oor (4),

(f) tilting said derrick (13) to align the drilling axis thereof with the axis of each of said conductor casngs (11a) in sequence and drilling said Wells through said conductor casings (11a) in sequence.

30. Method of drilling wells from a plurality of drilling stations spaced around the perimeter of an operating patform, said method comprising:

(a) positioning a derrick structure (13) on said operating platform (7) at one of said drilling stations,

(b) positioning a draw works (15 at said drilling station outboard of said derrick structure,

(c) positioning a pipe rack (81) in the central portion of said operating platform (7 inboard of said derrick structure,

the foregoing steps (a), (b) and (c) being performed in any order,

(d) drilling a well at said drilling station, then (e) shifting said derrick structure (13) to another drilling station,

(f) shifting said draw works (15 to said other drilling station and positioning said draw works (15) outboard of said derrick structure (13),

(g) reorienting said pipe rack (81) relative to said derrick structure (13) while maintaining said pipe rack (81) in the central portion of said operating platform (7),

the foregoing steps (e), (f) and (g) being performed in any order,

(h) drilling a well at said last mentioned drilling station, then (i) repeating steps (e), (f) and (g) in any order through the remaining drilling stations.

31. Method of drilling wells as in claim 30, further comprising:

(j) tilting said derrick structure (13) backward and away from the central portion of said operating platform (7 so as to overlie the draw works (15) when drilling an inclined Well at a drilling station.

32. Well drilling apparatus comprising:

(a) base means (12),

(b) a draw works (15) mounted on said base means (c) a derrick structure (13) mounted on said base means (12) and tilted at an angle to the horizontal with respect to said base means (12) so as to overlie said draw works (15), said derrick structure (13) having a drilling axis,

(d) pipe handling means (16) adapted to move drill pipe (48) towards or selectively away from said derrick structure (13) in a direction parallel to the longitudinal axis of the drill pipe (48) being moved 17 and intersecting the drilling axis of said derrick structure (13).

33. Well drilling apparatus comprising:

(a) base means (12),

(b) a draw works (15) mounted on said base means (c) a der-rick structure (13) mounted on said base means (12) and tilted at an angle to the horizontal with respect to said base means (12) so as to overlie said draw works (15), said derrick structure (13) having a drilling axis,

(d) a supporting arm (56) having a supporting end (60), said supporting arm (56) being mounted to said derrick structure (13) intermediate the top and bottom of said derrick structure (13),

(e) operating means (61) to extend the supporting end (60) of said supporting arm (56) to a position adjacent the drilling axis of said derrick structure (13) or selectively to retract the supporting end (60) of said supporting arm (56) away from said position.

34. Well drilling apparatus comprising:

(a) a base means (12),

(d) a rotary (14) mounted on said base means (12),

said rotary (14) having an operating aperture therethrough, the drilling axis of said derrick structure (13) registering with the longitudinal axis of the operating aperture of the rotary (14),

(e) said rotary (14) being operated by the said draw works (15).

35. Well drilling apparatus comprising:

(a) base means (12),

(b) a draw works (15) mounted on said base means (c) a derrick structure (13) tiltably mounted on said base means (12) for rotation in a vertical plane about a horizontal axis (52),

(d) means (29) to adjust the inclination of said derrick structure (13) about said horizontal axis (52) thereby to tilt said derrick structure (13) to overlie said draw works (15),

(e) a rotary (14) adapted to be operated by said draw Works (15),

(f) means (14a) pivotally mounting said rotary (14) on said base means (12) for rotation in a vertical plane about the same horizontal axis (52) as the derrick structure (13).

36. Well drilling apparatus as in claim 35, further comprising:

(g) said derrick structure (13) having a drilling axis,

(h) said rotary (14) having an operating aperture therethrough,

(i) the drilling axis of said derrick structure (13) registering with the longitudinal axis of the operating aperture of said rotary (14),

(j) the horzontal axis (52) intersecting the longitudinal axis ofthe operating aperture of said rotary (14).

37. Apparatus for drilling at a marine site a plurality of slanting wells in the marine bottom, said wells having a predetermined inclination to the horizontal and having a predetermined orientation with respect to each other, said apparatus comprising:

(a) a platform (1) adapted to be transported to and established at the marine site,

(b) a plurality of guide means (11) mounted to the platform (1), each guide means (11) corresponding in inclination to the horizontal and orientation with one of said wells to be drilled,

(c) a conductor casing (11a) in each of said guide 18 means (11) and adapted to tbe driven into the marine oor (4),

(d) .a derrick structure (13) adapted to drill through each of said conductor casings (11a) into the marine floor (4).

38. Apparatus for drilling at a marine site a plurality of slanting wells in the marine bottom, said wells having a predetermined inclination to the horizontal .and having a predetermined orientation with respect to each other, said apparatus comprising:

(b) a derrick structure (13) having a drilling axis and mounted on said platform (1),

(c) a plurality of guide means (11) mounted to said platform (1), each guide means (11) corresponding in inclination to the horizontal and orientation with one of said Wells to be drilled,

(d) a conductor casing (11a) in each of said guide means (11) and adapted to be driven into the marine floor (4),

(e) means (29) mounted to said platform (1) to adjust the inclination of said derrick structure (13) to a-lign the drilling axis thereof with the longitudinal axis of each of said conductor casings (11a),

(f) said derrick structure (13) being adapted to drill along said drilling axis through each of said conductor casings (11a) into the marine floor (4).

39. Apparatus for drilling at a marine site a plurality of slanting wells in the marine bottom, said .wells having a predetermined inclination to the horizontal and having a predetermined orientation with respect to each other, said apparatus comprising:

(b) a plurality of guide means (.11) mounted to the platform (1), each guide means (11) corresponding in inclination to the horizontal and orientation with one of said wells to be drilled,

(c) a conductor casing (11a) in each of said guide means (11) and adapted to be driven into the marine floor (4),

(d) a derrick structure (13) tiltably ,mounted on said platform (1) for rotation in a vertical plane about a horizontal axis (52), said derrick structure (13) having a drilling axis,

(e) means (29) mounted to said platform (1) to adjust the inclination of said derrick structure (13) to align the drilling axis thereof with the longitudinal axis of each of said conductor casings (11a),

(f) a rotary (.14),

(g) means (14a) pivotally mounting said rotary (14) to said platform (1) for rotation in a vertical plane about the same horizontal axis (52) as the derrick structure (13), the rotary (14) having .an operating aperture therethrough, the axis (52) intersecting the longitudinal axis of the operating aperture, the drilling axis of the derrick structure (13) registering with the longitudinal axis of the operating aperture of the rotary (14),

(h) said derrick structure (13) being adapted to drill .along said drilling axis through each of said conductor casings (11a) into the marine oor (4).

40. The method of drilling at a marine site a plurality of slanting wells in the ymarine 1bottom, said Wells having a predetermined inclination to the horizontal and a predetermined orientation with respect to each other, said method comprising:

(a) fabricating a platform (1) with a plurality of guide means (11), each guide means (11) having an axis Vcorresponding in inclination to the horizontal and orientation with one of said wells to -be drilled,

(b) transporting said platform (1) to the marine site,

(c) orienting and establishing said platform (1) at the marine site so that the axis of each guide means 19 (11) registers with the .axis of one of said wells to Ibe drilled,

the foregoing steps (a), (b) and (c) being performed in the order named,

(d) driving conductor casings (11a) through the guide means (11) along the axes of said guide ,means (11) into the marine oor (4),

(e) mounting a derrick (13) having a drilling axis on said platform (1).

the foregoing steps (d) and (e) being performed in any order,

(f) aligning the drilling .axis of the derrick (13) with the axis of one of said conductor easings (11a) and drilling a well in .said marine oor (4) through said conductor casing (11a),

(g) repeating step (f) through the remainder of said conductor casings (11a).

41. Apparatus for drilling a slanted well at .a site, said apparatus comprising:

(a) a platform (12) adapted to be stably supported at the site,

(b) draw works mounted on said platform (12),

(c) a derrick structure (13) mounted on said platform (12), said derrick structure (13) having a drilling axis tilted at an angle to the horizontal so as to overlie said draw works (15),

(d) a rotary (14) mounted on said platform (12),

said rotary (14) having an operating aperture therethrough, the longitudinal axis of the operating aperture of the rotary (14) being tilted at an angle to the horizontal,

(e) the drilling axis of said derriek structure (13) registering with the longitudinal axis of the operating aperture of the rotary (14).

42. Apparatus for drilling a slanted Well at a site, said apparatus comprising:

(a) a platform (12) adapted to be stably supported at the site,

(b) draw works (15) mounted on said platform (12),

(c) a derrick structure (13) tiltably mounted on said platform (12) for rotation in a vertical plane about a horizontal axis (52),

(d) means (29) to adjust the inclination of said derrick structure (13) about said horizontal axis (52) thereby to tilt said derrick structure (13) to overlie said draw Works (15 (e) a rotary (14),

(f) means (14a) pivotally mounting said rotary (14) on said platform (12) for rotation in a vertical plane about the same horizontal axis (S2) as the derrick structure (13).

43. Apparatus for drilling a slanted well at a marine site, said slanted well having a predetermined inclination to the horizontal, said apparatus comprising:

(b) .guide means (11) mounted to said platform (1) .and corresponding in inclination with the inclination of the well to be drilled,

(c) a conductor casing (11a) in said guide means (11) and adapted to be driven into the marine floor (4),

(d) a derrick structure (13) having a drilling axis and mounted on said platform (1), said drilling axis Ibeing inclined to the horizontal and .aligned with the axis of said conductor casing (11a),

(e) said derriek structure (13) being adapted to drill along said drilling axis through said conductor casing (11a) into the marine oor (4).

References Cited UNITED STATES PATENTS 1,267,129 5/1918 Sewall 175-7 X 1,900,163 3/1933 Dana et al. 175-9 2,503,516 4/1950 Shrewsbury 175- 8X 2,699,321 1/1955 Nelson 175-8 2,792,198 5/1957 Braun 175-85 X 2,848,196 8/1958 Simmonds 175-85 X 2,927,435 3/1960 Upson 61-46 3,004,612 10/1961 Kofahl 175-9 X 3,125,171 3/1964 Stewart 175-7 X 3,212,593 10/1965 Reischl 175-85 3,252,527 5/1966 Alexander et al. 173-44 X CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner.

U.S. Cl. X.R. -85, 220

Disclaimer 3,451,493.James 0. Stamm, Corpus Christi, Tex. DRILLING APPARATUS AND METHOD. Patent dated June 24, 1969. Disclaimer filed Dec. 10, 1971, by the inventor.

Hereby enters this disclaimer to

claims

27, 34 and 41 of said patent [Off/'cial Gazefe Illa/M11, 7, 1.972.]