US2628818A - Well drilling rig - Google Patents

Description

Feb- 17 1953 T. s.- GRAHAM 2,628,818

WELL DRILLING RIG INVENTOR. T. S. GRAHAM ATTORNEYS Feb.r17, 195.3 T. s. GRAlL-IAM y 2,628,818

WELL DRILLING RIG Filed May 1e, 1949 5 sheets-sheet 2 INVENTOREZ" T. S. GRAHAM A TTORNEVS Feb. 17, 1953 T. SGRAHAM 2,628,818

WELL. DRILLING RIG Filed May 1e, 1949 5 sheets-sheet 3 1N VEN TOR. T. S. GRAHAM A T TORNEYS Feb. 17, 1953 T. s. GRAHAM WELL DRILLING RIG 5 Sheets-Sheet 4 Filed May 16, 1949 INVENToR.' T. S. GRAHAM ATTORNEYS 5 Sheets-Sheet 15 F IG. /0

- INVENTOR. r s. GRAHAM A TTORNEYS Feb. 17', 1953: T. AHAM w'mnmmc nrc PUMP |23 Patented Feb. 17, 1953 WELL DRILLING RIG Tom S'. Graham, Alvin, TeX., assignor to Phillips Petroleum Company, a corporation of Delaware Application May 1e, 1949, serial No. 93,514

This invention relates to well drilling rigs. In one specic aspect it relates to well drilling rigs having improved types of foundations. In another specic aspect it relates to well drilling rigs which may be rotated into a plurality of positions to'drill a plurality of wells. In another specific aspect it relates to well drilling rigs particularly adapted for use in marine locations, especially in the open sea along the continental shelf,`

Geological formations containing'valuable dev posits such as oil and/or gas may exist under the surface of bodies of water. These formations are being exploited by drilling wells down to the same. The drilling rigs used in such marine locations are subject to the destructive forces of nature, especially wave action. In non-marine locations as well as in marine 1ocations,.espe cialiy when Vthe foundation required is expensive or difficult to install because of the nature of the ground and/or water covering the location, it is especially desirable to be'able to drill morethan one Well so that the `expense of the foundation can be divided between several wells. These Wells of course can be deflected su'iciently below the surface of the ground to be properly spaced by the time the producing formation is penetrated.

Numerous designs proposed in the prior art have proved to be impractical because of the cost of under water construction or destruction by wave action especially during storms.

One object of the present invention is to provide an improved type of well drilling rig.

Another object is to provide a suitable rotatable well drilling rig capable of drilling a plurality of spaced wells when positioned in a plurality of positions during rotation.

Another object is to provide a well drilling rig which may be erected in the marine location without connecting t-he supporting members to- :gether under Water.

` Another object is to provide a marine foundaltion for 4a drilling rig in which vibration and wear and tear by wave action is minimized.v

Another object is to .provide a foundation for a marine location which may be removed when- .everthe location is to be abandoned without disconnection of parts under water except for pulling out, or breaking off short a few simple vertilca1 piles, which can be done with a tug boat, or

the like.

Numerous other objects and advantages will be apparent to those skilled in the art upon reading shown in Figure l illustrating use in a .marine a bearing for use location, parts 4shown being broken away, or in cross section, to show details of construction.

Figure 3 is a plan view of the foundation shown in Figure 2 which is. generally below the line 3-3 of Figure 2 looking in the direction indicated with the location of future wells indicated by dotted line circles.

Figure 4 is a plan viev'cr of the frame fcr supporting a derrick (not shown) which is rotatably mounted on the top of the structure shown in Figure 3.

Figure 5 is an enlarged fragmentary elevational i View of the upper portion'of Figure 2 taken at right angles thereto showing the same well drilling rig of theV preceding figures in the operation of drilling al Well.

y Figure 6 is a plan view of a modied form of in place of the bearing shown in Figure 3.

Figure 7 is a cross Isectional view of the bearings shown in Figure 6 taken along the lines v'l--l of said iigure looking in the direction indicated.

Figure 8 is a cross sectional view of a third form of the bearing.

Figure 9 is an elevational View of the major Figure 10 is a cross sectional view of a portion ofthe pipe rack of Figure 2 showing details of construction.

Figure 11 is a view similar to Figure 10 showing details of constructionV of a modied form of pipe rack.

In Figure 41 a platform |6is mounted on` a frame generally designated as I1. Frame I1 is preferably formed from inner and outer concen tric annular members I8 and I9 respectively secured together by radial members 2i. Platform I 6 is preferably secured to frame l1 by longitudinal girders 22'. Girders 22 support the legs 23, 24, 26 and 21 'of a four-legged derrick generally designated as 25, which derrick has a centrally located rotary table `23 and a draw works 29 both mounted` on derrick platform i6., if the rotary method of drilling .is employed. When other drilling methods uare employed rotary table 23 is not present andthere is merely a centrally located opening infloor I6 over the` proposed well 3l.

As shown in Figure 2 derrick legs 21 and 26 are capped by a crown block housing 32 having removably secured thereto in the conventional manner a conventional crown block centrally located over well 3 I so thaty traveling block 33 can raise and lower well drilling equipment from by centrally disposed vertical forces, thereby creating forces of reaction' acting equally on derrick legs 23, 24, 26 and 21, and preferably said reaction forces will comprise mainly a simple force of compression axial of each leg.

Traveling block 33 is operated by a cable from draw works 29 in the customary'l manner.

Suitable driving means comprising motors 34 and 36 are provided for draw works 29 and rotary table 28 respectively.

In many instances it is desirable to service the well drilling rig from a tender (not shown) which tender often is a LST (landing ship for military tanks) anchored near the rig with its bow preferably in the direction of prevailing winds and said ship being in the lee of said well drilling rig. Said ship may generate power to drive the motors 34, 36 and 93 of the drilling rig and transmit the same to the rig, and mud pumps similar to 92, mud tanks similar to 89 and other structure (not shown) may be provided on the ship which may act also as a rack for pipe. Motor 93 as shown in Figure 5' drives a conventional mud pump 92, pumping well-drilling mud from tank 89 into pipe 9| from whichv it proceeds by the usual flexible pipe (not shown) into the drill pipe 81, 84, down to the bottom of the well and out holes in the well-drilling bit (not shown) from which the i mud returns to surface through casing 33 and flow line 94 back into mud tank 89.

When such a ship (not shown) is used it is convenient to rotate frame into a position for drilling the first well 3| so that the ship may be inthe lee of the rig and most convenient for transferring pipe thereto. By the time well 3| is finished, the prevailing Winds may seasonally shift so that a second wellk suoli as 31- then becomes more convenient to work with and then may be drilled. However, anyone of the six wells 3|, 37, 52, 53, 54 and 56 shown, and wells intermediate thereto, may be drilled regardless of the direction of the prevailing winds by suitably anchoring the ship (not` shown). Generally some means of arranging the ship so it will not be on Athe Windward side of the rig can be devised, as it is undesirable to have a ship anchored to windward, Where itcould break loose from its anchors in a, storm and be driven against the rig.

While a ship can be employed as a pipe rack I prefer to use a movable pipe rack generally designated as 38. Pipe rack 38 comprises a framework composed of members 39, 49, 4|, 42. and 43 secured together and pivoted to frame by pivots 44 runthrough holes of. greater diameter than pivots 44 in lugs 50 on beam 46 secured to members |9 and 2|. rlp'he hole in lug 50 of greater diameter than pivot 44 is shown in dotted lines around 44 in Figure 2'. Pivot 44 obviously may be provided with retaining means on each end, such as a nut thereon (not shown). As shown in Figure 9-vertical members 42 are secured together by horizontal members 45 and cross bracing members H6. An auxiliary pipe supporting beam 41 may alsobe secured to members 2| to extend the effective length of the pipe rack 38 to handle longer pipe 5|. Pipe rack 33 j has vertical legs 43 and 49 which will be de- `be drilled by rotating frame I1, in practice it is best to drill not more than six wells 3|, 3l, 52, 53, 54 and 56 so that during the drillingl the legs 2,3, 24, 2B and 2'( of the derrick will each be above,

, or substantially above, a supporting pile, as will .be explainedlater.

In Figure 2 the structure shown has been erected by driving twelve piles into the ground 51 which may or may not be covered by water 58. The twelve piles are driven into the ground in the form of concentric hexagons, in Figure 2 piles 59 and 6| being in the inner hexagon and piles 62, 63, 64 and 66 being in the outer hexagcn. Two piles in the inner hexagon are hidden behind piles 59 and 6| and two are hidden behind piles 63 and 64. Two of the piles in the outer hexagon are :also hidden behind 93 and E4.

While not necessary to some aspects of the invention, nevertheless it is preferable in exposed locations, to secure the upper portion of said piles together by cross bracing members El and (59 at a plurality of levels. Sway bracing members 53 and l l. may be provided to strengthen the foundation.

It is realized that such bracing is old in engineering structures generally, but the following features are believed to be novel, namely, that all of said framework is at an elevation greater than the minimum low tide level of water 58 so that all of said bracing members 6l, 53, E9 and can be erected on and removed from piles 5| 32 etc. in situ without under water operations. Fastening parts together under water is both expensive and unsatisfactory, and generally reduires the employment of divers. Divers are especially skilled workers having a very high wage rate and generally can only work in the calmest of weather. Preferably all of said framework is at an elevation greater than mean high tide by distance greater than one-half the average wave height inA order to minimize vibration of said drilling rig by waves passing through the foundation. By wave height is meant the vertical distance between the crest and. trough of a wave. The average wave height is the average throughout the year at that location.

It is realized of course that during storms waves are going to pass through the framework and perhaps above members B7, and a generally open construction of members 68, |59 and l! will minimize the eiect oi the waves. Nevertheless each member 68, 69 and 1| that is submerged in the wave receives a force from the wave which tends to destroy the structure especially after endless repetition, By having brace 98 above the usual wave height, a constant beating of waves on the structure is avoided and the structure is therefore in better shape to resist occasional storms.

The piles 59 to 66 are preferably capped with radial I beams 12 which in turn may be framed with prefabricated girders '.13 and 14 as shown in Figure 3. A bearing 16, or 11, is secured to the prefabricated girders 13 land 14 secured to the radial I beams 12 above the top of each pile and these bearings may be anti-friction bearings having rollers which will be described later with reference to Figures 6 to 8.

'If desired a fender 'F8 may be provided extending around the entire structure to receive and absorb a limited amount of shock from a contacting ship by means of springs 79. Fender 19 is preferably resilient and will bend and return to shape uponrelease of the bending force. Bolts 8| are screwed into holes in the fender 13 at points opposite piles such as 62 and 66, and bolts 8| are also movably mounted in holes 39 in the pile.V

Figure 4 shows frame l1 in more detail than was possible in Figure 1. Circular tracks i8 and |9 of the frame are adapted to be supported for rotation on the tops of the outer and inner bearings 16 and 11 respectively. i

"a'eesfaie As shown in Figure 2 pipe` platform 38 consists of vertical members 42 and horizontal members 39 secured together' by brace members 43. The inner end of the platform 38 is supported on I beam 46 and the outer end 42 is slidably mounted on leg 48. Leg y48 is provided with a suitable foot 82.

A suitable positioning means 83 may be pro- `vided for positioning pipe 42 on pipe 48 as will be explained below. Y

Platform 38 may be removed, preferably by pickingy the same up with` a derrick on a ship (notshown) and moving it from one position to another whenever derrick platform I1 is rotated.

In Figure further details of the well drilling operations are shown. While reciprocating drilling, advancing-motor drilling, and other methods of well drilling may be employed, it is generallyT preferred to employ the rotary well drilling system in which a string of drill pipes 84 is lowered into a well casin-g 86 and is rotated by a rotary table 28 through a kelly 81. lThe drill string is lowered by cable 88 and the traveling block 33 is actuated byreeling cable` 88 on and off of draw works 29. Drill string 34 has a cutting bit (not shown) on its lower end and well drilling mud from tank 89 is pumped through pipe 9| by pump 92 driven by motor 93 down through kelly`81 and pipe 84 out the drillbit and up the annular space between pipe 84 and casing 86 and then returned to mud tank 89 through pipe 94. Well casing 88 `may be provided with a master gate valve 96,

blowout preventor 91, and drilling stuiiing box 98. As each well 3|, 52, etc. is completed, it is arranged with conventional flow lines shown) below member 13 so as to be out of the way of the rotating upper parts on platform I1.

Platform I1 may be rotated by various means such :as one or more motors 99 mounted on brackets |0| on platform I1 and engagingmember 13 with a driving wheel |92 driven by a shaft |83 of motor 99. In practice, wheel |82 is a gear wheel of small diameter as shown and engages a rack or cog track I secured to member 13. If desired reducing gearing may be employed between motor 99 and gear |82. If desired rack |05 can be mounted inside of 14 and the motor drive 99 can be secured to the inside of ring member I9 instead of member I9 as shown.

Details of the bearings such as 16 are shown in Figures 6, 'l and 8. In Figures 6 and '1 the bearings comprise conical rollers |il4 having shafts |06 journaled in raised sides I 61 and I 88 of bearing block 16 in any friction-bearing (not shown) or ordinary shaft bearings |89 as shown in Figure 7. Side |88 is higher than side |81 and than bearing roller |84 so that these high sides of the bearing will engage I beam ring member I9 oi the platform |1 and center the same.

In Figure 8 rollers III rest on bed I|2 which is provided with anti-friction means comprising grease pumped in through fitting ||3 and passage I4.

As shown in Figure 9 the pipe platform 38 formed of vertical members 42 secured together by horizontal members may also be provided with cross bracing members I I6.

In Figure 10 it will be seen that member 42 is slidable on leg 48 and may be positioned thereon by positioning means 83 of Figure 2 comprising an adjustable length chain and adjusting clamp ||1, connecting lug ||8 on member 48 with lug I9 on member 42. The adjustable positioning is obtained by bringing up a ship, such as an LST (not Y (not shown), with a drrick' (not shown), which picks up 42 by means of bar 45 and adjusts the same, whereupon a sailor may adjust clamp II'I and thereby tighten chain |8 so that uponv disengagement of the derrick the member 42 has 4been fastened in an adjusted position.

In Figure 11 members 43 and 39 are connected with a vertical tubularv member I`2| which reh secured together by pin |3I so there is no relaof valve |28.

Operation Six piles are driven in the form of a hexagon and then six more piles are driven in the form of a hexagon concentric with the i'lrst hexagon. The portion of the piles 6| to 64 etc. above the minimum low tide level are then fastened together by welding or bolting on members 61, 69, 1 I, 12 and the like. Each pile has a bearing such as 16 or 11 directly above the pile. Y Rotatably mounted on bearings 16, 11 etc. is platform |1 having a derrick -generally designated as 25 mounted thereon. It will be noted in Figures 1 and 3 that as the derrick is positioned over each one of wells 3|, 52, 31, 53, 54 and 56 that each of legs 23, 24, 26 and 21 of the derrick will be above :a bearing and the bearing will be directly above a pile. For example, in drilling well 3|, leg 23 of Figure 1 will be above bearing |32 of Figure 3, and similarly leg 28 will be above bearing |33, leg 21 above bearing |34, and leg 24 above bearing |36. The same situation occurs in drilling the other five Wells, in each instance each le-g of the derrick is above a bea-ring. Furthermore the far end of platform IS is above bearing |31 and 16, so that platform I8 as a Whole is supported on six of the bearings di rectly over piles. Furthermore platform I1 with rings IS and I9 is always supported by all 12 bearings.

While I have shown a preferred embodiment of the invention for purposes of illustration, the in f' vention is not limited thereto but is of a scope commensurate with the appended claims.

Having described my invention, I claim:

l. A well drilling rig comprising in combination a foundation secured to the earth, first bearing means disposed in two concentric horizontal circles secured to said foundation, a frame comprising a well drilling derrick having four legs and a derrick floor, a rotary table mounted on said derrick. floor, and second bearing means secured to said frame and disposed to engage said first bearing means to vrotatably support said frame and derrick on said foundation, each of said derrick legs being always disposed above said second bearing means, two of said legs being always disposed above the outer and two above the inner of said concentric circles, and said rotary table always being disposed with i-ts central vertical axis inside of said inner concentric circle.

2. The combination of claim l in which the 'r'7 cierriclrI scola-reV` in horizontal cross-sectional area.

3. The combination of' claim 1A in whichthe derrick. has` a. crown block, andl the crown block and rotary table are mounted in the center of 4the derrick.

il The combination of` claiml in which the derrick is squarel in horizontal cross-sectional area andhas a crown. block, and the crown block and rotary table are mounted in the center of thek derrick.

5. The combination of claim 1. in which the foundation comprises a plurality of piles driven intoy the earth and disposed in said tivoV concentric circles, and the firstV bearingr means comprises bearings secured to the top of a plurality of said piles.

6. The combination of claim. 5 in which, there are six piles in the inner crolev and six piles in the outer circle disposed in the form oi two con centric regular hexagons, and the frame is rotatable to position said derrick in six positions to drill six wells with each leg of said derrok disposed in each position adjacent the vertical axis of a pile to thereby reduce the forcesl tending to warp said frame during the drilling of said wells.

'l A Well drilling rig comprising in combination a foundation secured to the earth, first bearing means disposed in two concentric horizontal circles secured to said foundation, a frame oomprising a well drilling derriok` having four legs and a derrick floor, and second bearing means secured to said frame and disposed to engage said rst bearing means to rotatably support said frame and derrick on said foundation,

each of said derrck legs being Aalways .diS- posed above said second bearing means. and two of said legs being always disposed above the outer and two above the inner of said concentric circles.

8. The combination oi claim 7 in which the foundation comprises a plurality of piles driven into the earth and disposed in said two concentric circles, and the first bearing means comprises lbearings secured to the top of a plurality oi said piles.

9. The combination of claim '7 in which there are six piles in the inner circle and six piles in the outer circle disposed in the form of two concentric regular hexagons, and the frame is rotatable to position said derrick in six positions to drill six wells with each leg of said derricl: disposed in each position adjacent the vertical axis of a pile to thereby reduce lthe forces tending to Warp said frame during the drilling of said wells.

TOM S. GRAHAM.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,097,225 Hansen May 19, 1914 1,769,858 Roberts July 1, 1930 1,904,249. Powell et al Apr. 18, 1933 1,998,803 Collins Apr. 23, 1935 077,(144, Grace et al. Apr. 13, 1937 2,248,651 Armstrong July 8, 1941 2,399,656 Armstrong May 7, i946

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