US2171672A - Underwater drilling - Google Patents

Description

Sept. 5, 1939. w. B. PLUMMER 2,171,672

UNDERWATER DRILLING Filed Sept. 50, 1937 2 Sheets-#Sheet 1 2g .v ATTORNEY Sept. 5, 1939. w. a. PLUMMER UNDERWATER DRILLING Filed Sept. 50, 1937 2 Sheets-Sheet 2v INVENTQR W////am B. plum/17er BY g/. M

ATTORNEY UNITED STATES PATENT OFFICE UNDERWATER DRILLING William B. Plummer, Chicago, Ill., assignor to Standard Oil Company, Chicago, Ill., a corporation of Indiana I Application September 30, 1937, Serial No. 166,483

7 Claims.

drilling chamber, and method of installing the same, whereby the maximum strength and stability is imparted to the foundation while at the4 .5 same time the minimum area of superstructure is exposed to wave action.

It is a still further object of this invention to employ in the above combination a shell having its lower end open and to provide a method of zo sinking this open end in the underlying bed and l sealing the same against ingress of water into the drilling chamber in order to render the chamber safe for workmen and machinery.

The above and other objects and advantages 25 of my invention will become more apparent from a reading of the following specification and claims taken in connection with the appended drawings which form a part of this specification and wherein:

30 Figure l is a vertical section of a derrick and underwater drilling chamber in accordance with my invention.

Figure 2 is a modication wherein the work platform is positioned above the water level.

35 Figure 3 is another modification showing the usual type of derrick mounted on my improved formv of foundation and provided with a work platform above the water level.

Figure 4 illustrates schematically a modica- 40 tion of lmy improved method of installing the foundation.

Figures 4a. and 4b illustrate different relative positions of the parts shown in Figure 4.

Figure 5 illustrates schematically a further 45 modification of my improved method of installing the foundation.

Referring in greater detail to Figure 1 there is shown in position on the underlying bed B a derrick I including in combination an under- 50 water drilling chamber in accordance with a preferred embodiment of my invention.

This combination consists essentially of a tubular shell II, provided at its lower end with a conical or hemispherical enlargement I2 at the s lower, larger end of which there is a second or (Cl. Z55-1) base shell I3 open at its lower end and provided with a. cutting edge I4, the whole being in effect a caisson. When completely installed the enlargement I2 defines an underwater drilling chamber. The shell II is preferably from 4 to 5 l0 feet in diameter depending upon the requirements of a particular installation such for cxample as the size of the equipment which must be lowered therethrough. In some cases I prefer to include certain of the larger pieces of the equipment such as the rotary I5 and draw works I 64 within chamber I2 before installing the derrick. This makes it possible to construct shell II with a smaller diameter. The structure as a whole resembles an inverted funnel. Brackets Il positioned about the upper inner periphery of base shell I3 are adapted to support work platform I8 for carrying thedrilling equipment such as the rotary I5 and draw works I6, etc. Bracket I9 mounted in shell II supports crown block 20 20 over which is reaved cable 2l of the draw works I6. Cable 2I supports traveling block 20a from which is suspended hook h and swivel head 33 in the usual manner. Above bracket I9 is indicated a pair of closures 22 and 23 forming an 25 air lock arrangement. Air lines 24 and 25 lead from a suitable source of compressed air located on a barge 26 for operating the air lock, certain of the details of which are omitted for the purpose of simplifying the disclosure. The air lock 30 compartment defined by closures 22 and 23 contains a swinging boom type of hoist 21 for use in removing dirt and material from the lower compartment according to well known sand hogging practice. V The derrick I0 is installed by first placing it in an upright position with the open end of shell I3 resting on the underlying bed and then producing a depression thereunder and causing the structure to be lowered into this depression. This may be accomplished by pumping out the contents of the shell as with a hose and pump, thus removing the bed within and at the base of shell I3 resulting in the formation of an opening into which shell I3 is caused to be lowered. On the other 45 hand this may be accomplished by carrying out the usual "sand hogging operations within the shell or caisson I Il. 'I'his consists essentially of maintaining a suflicient air pressure within the lower chamber to keep out the water while removing the dirt from within and at the base of shell I3 and thus causing the structure to sink into the opening so formed. 'This dirt is taken out through the air lock closures 22 and 23 lo- 55 cated in the upper portion of shell 'I I according to the usual procedure.

When the' structure has been lowered to the desired depth, concrete 28 is poured into shell I3 about caisson or pipe 29 and a temporary form for sealing the structure against ingress of water. This form is later removed providing the usual cellar 30. Pipe 29 is maintained closed by a cover plate (not shown) until drilling operationsare to be conducted therethrough. It may begnecessary to maintain the drilling chamber I2 under suitable pressure until drilling and casing off has proceded to a safe depth, to insure against leakage of water therein after which the air lock closures 22 and 23 may be left open to the atmosphere.

'I'he service barge 26 which is anchored 'adjacent the upper end of shell II, isl also provided with a hoist or crane 3| for lowering the neces-v 'sary drilling equipment through the shell II.,

The service barge 26 may also carry the drilling mud, however, a separate mud barge may be employed. Mud delivery line 32 connects the mud supply on the barge with the swivel head 313 under the control of valve 3l. while line 35 returns the mud'overilow to the barge for settling and reconditioning before being returned, all in a manner which is well known.

In drilling a well through pipe 29 following the installation of drilling machinery within the drilling chamber I2, the rst string of casing is introduced through closures 22 and 23 and lowered into position on the usual supply rack (not shown) accessible to the workman, by means of the hoist 3| on the barge. The necessary string of drill pipe (not shown) is likewise introduced into, the caisson and likewise temporarily placed on a suitable rack (not shown). Next drilling chamber I 2 is preferably placed under suicient pressure to assure against the ingress of water when the closure plate (not shown) on pipe 29 is removed. .The drilling operations-are carried out by introducing the string of drilling pipe carrying the drill into pipe 29 and rotating the same by means of the rotary I5 while supplying drilling mud through line 32, following which the string of drilling pipe is removed and the rst string of casing 36 is introduced and cemented off all in a well known manner. The closures 22 and 23 of the air lock may be opened to the atmosphere while the drilling is continued to the desired depth since there should be noV further leakage after cementing in the flrst'string of casing.

It will thus appear that by extending tubular section I I of relatively small cross section to a point below the level of the wave action and providing an enlarged drilling chamber therebelow, a more stable and satisfactory arrangement for drilling a subaqueous well is provided.

' In Figure 2 there is presented a modiilcation of the arrangement of derrlck and foundation shown in Figure 1. A tubular shell 50 is provided on its lower end with a conical or hemispherical portion 5I at the lower, larger end of which there is a second or base shell 52 open at its lower end and provided with a cutting edge 53. The derrlck 54 is composed in the usual manner of four legs 55 and bracing members 56. This structure is mounted on the top of base shell 52 in embracing relationship with respect to shell 50. Mounted on the upper end of tubular shell 50 and attached to the side members 55 of derrick 54 is a work platform 51 adapted to 'be mounted above the water level when the structure is installed on the underlying bed as shown.. Bracket 58 on the upper portion of derrlck 64 is adapted to receive the usual crown block such as block 20 shown in Figure 1. 'I'he other drilling equipment including the rotary, the drawl works, etc., such as shown on work platform I8 of Figure 1, will be mounted on the work platform 61, these elements not being shown in Figure 2, in order to simplify the disclosure. The upper end of tubular shell 50 is provided with air lockl closures 59 and 60 adapted to be connected with a supply of compressed air on a barge anchored adjacent thereto for operation as in Figure 1.

The structure is installed in position on the underlying bed inthe same manner as in the case of thestructure of Figure 1, which includes anchoring and sealing the base of shell 62 with concrete.

In Figure 3 there is shown a still further modiilcation of my inventionwherein theusual form of derrlck structure 15 such as that employed in Figure 2 comprising essentially four legs 16 fastened together by bracing members 11. Each leg 16 is supportably attached on the upper end of an individual shell or caisson 16. Each of these shell or caisson supports is open at its lower end and provided with a cutting edge 19. Lines 60 connect withv a suitable pump on a barge located as shown in Figure 1 for pumping out the interior of the shells 18. Derrick 15 is provided with a vwork platform 0I .located above the water level vand adapted to carry the drilling equipment, such as described in connection with Figures 1 and 2. This structure is likewise installed by positioning the shells 16 with their open ends resting on the underlying bed and removing the bed from within and at the base of the shellsto form an opening and causing the respective shells to sink therein. 'Ihis is eiected by pumping out the water and vsuspended material through lines 80. Following this operation concrete is pumped into the shells 16 to anchor the same.` The concrete may be introduced through line 80 or where desired a separate line (not shown) may be employed for this purpose.

In Figure 4` there is shown ,schematically a modification of the improved method and arrangement of apparatus of Figure 3. Foundation shell- |00 corresponding to shell 18 in Figure 3 is surrounded by anauxiliary shell I0| open at both ends and of a Vslightly lgreater Adiameter than shell |00, thus dening an annular space therebetween. By this means the water currents outside the shell |00 induced by pumping out the inside of the shell are localized and the erosion of the bottom soil is confined to the circular area directly under the shell preventing any tendency to form a crater in the be the shell.

Figures 4a and 4b shown additional possible relative positions of the bottom edges of shells |00 and IOI depending upon the condition of the bottom. I

In Figure 5 there is shown schematically a further modification of the improved method and apparatus of Figure 3. The foundation shell or caisson corresponding to caisson |00 of Figure 4 is additionally `provided `with a guide |26 for cooperationlwitha guide |21 for maintaining the caisson in a vertical position while being installed. In shallow water particularly, guide |21 may take the form of 4a pile previously installed in the usualmanner. A suitable seal |28 is provided to prevent pumping action through the guide opening |26 about the guide i riurrounding |21. 'I'his arrangement is of particular importance where the caissons are to be put down individually and the derrick l-ater mounted thereon.

It is to be understood that various changes in the form, proportion and size, as well as in the particular manner of fabrication, may be resorted towithin the scope of my invention without departing from the spirit or broad concept thereof, and I do not intend to be limited by the specific embodiments disclosed further than as indicated by the appended claims, which should be construed as broadly as the prior art will permit.

I claim:

1. In an apparatus for drilling a well under a body of water, a caisson having an enlarged lower portion, the rim of said lower portion being provided with a depending cylindrical shell open at its bottom and formed with a cutting edge, said enlarged lower portion defining a working chamber wherein drilling operations are to be performed, the upper portion of said caisson defining a passageway sufciently large to permit of passage of workmen and tools `and being provided with an air lock adjacent the upper end thereof,'said shell being adapted to be lowered into an opening in the bed underlying said body of water by sand hogging.

2. In an apparatus for drilling a well under a body of water, an inverted funnel-like caisson, the rim of the funnel being provided with a depending 'cylindrical shell open at its bottom and y ing a subaqueous well, comprising a tubular shell formed with an enlarged lower portion open at its lower end, the upper end of which is converged into a neck portion of reduced cross-sectional area, a derrick mounted about said reduced neck portion with the legs thereof supported by said enl-arged lower portion, said last-named portion being sunk into a 'depression in the underlying water bed and filled at least partially with concrete to anchor the same, and a work platform positioned about the upper end of said reduced portion above the water level adapted to support drilling equipment for drilling through said tubular shell.

4. The method of installing a derrick for drillingla well under the surface of a body of water which comprises attaching each leg of said derrick to a tubular shell open at its lower end, evacuating said shells to cause them to be lowered into the opening thus formed in the bed of said body of water, and filling said shells with concrete to stabilize the same.

5. A derrick and foundation therefor for drilling a subaqueous well, comprising a plurality of legs, a plurality of caissons for supporting said legs, each of said caissons being open at the lower end to facilitate installation on the underlying bed, means for pumping out each of said caissons to produce an opening in said bed thereunder and to effect the settling of said caissons therein, and means for introducing concrete into said caissons to anchor the same.

6. The apparatus as defined in claim 5 wherein there is provided a tubular shell open at both ends surrounding said caissons for controlling the erosion about the base thereof during pumping.

7. The apparatus as defined in claim 5 wherein said caisson is provided with guide means for insuring the vertical movement thereof while being lowered into said opening.

WILLIAM B. PLUMMER.

Images