2,171,672. ' did 7? Sept. 5, Wi/a/AA/l/m/mer. W. B. PLUMMER UNDERWATER DRILLING Filed Sept. 30, Sheets-Sheet 2 ATTORNEY INVENTOR

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2 Sept. 5, W. B. PLUMMER UNDERWATER DRILLING Filed Sept., Sheets-Sheet 2? INVENTOR Wi/a/AA/l/m/mer ' did 7? ATTORNEY

3 Patented Sept. 5, 1939 UNITED STATES Claims. This invention relates to subaqueous drilling, especially well drilling, and has as its object the provision of an improved method and apparatus for subaqueous drilling, particularly for use in areas where the water is deep and/or rough. It is an object of this invention to provide an inproved derrick structure and foundation there for together with an improved method of install ing the same. PATENT OFFICE 2,1711,?72 UNDERWATER ORLLING William B. Plummer, Chicago, Ill., assignor to Standard Oil Company, Chicago, Il., a corpora tion of Indiana Application September, 1937, Serial No. 166,483 A further object of this invention is to provide a novel combination of derrick and underwater drilling chamber, and method of installing the same, whereby the maximum strength and sta bility is imparted to the foundation while at the 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 sinking this open end in the underlying bed and 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 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: Figure i is a vertical section of a derrick and underwater drilling chamber in accordance with my invention. Figure 2 is a modification wherein the work platform is positioned above the water level. Figure 3. is another modification showing the usual type of derrick mounted on my improved form of foundation and provided with a work platform above the water level. Figure 4 illustrates schematically a modifica tion of my improved method of installing the foundation. Figures 4 a. and 4b illustrate different relative positions of the parts shown in Figure 4. Figure 5 illustrates schematically a further 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 to including in combination an under Water drilling chamber in accordance with a pre ferred embodiment of my invention. This combination consists essentially of a tubul lar shell, provided at its lower end with a conical or hemispherical enlargement 2 at the lower, larger end of which there is a Second or (Cl. 5 1) base shell 3 open at its lower end and provided with a cutting edge 4, the whole being in effect a caisson. When completely installed the en largement 2 defines an underwatcr drilling chamber. The shell f f is preferably from 4 to 10 feet in diameter depending upon the require ments of a particular installation such for ex ample as the size of the equipment which must be lowered therethrough. In some cases I pre fer to include certain of the larger pieces of the equipment such as the rotary 5 and draw works 16 within chamber 12 before installing the der rick. This makes it possible to construct shell with a Smaller diameter. The structure as a whole resembles an inverted funnel. Brackets f7 positioned about the upper inner periphery of base shell 3 are adapted to support work plat form 8 for carrying the drilling equipment such as the rotary 5 and draw works 6, etc. Bracket 9 mounted in shell supports crown block over which is reaved cable 2 of the draw works í6. Cable 2í supports traveling block a from which is suspended hook b and swivel head 33 in the usual manner. Above bracket 9 is in-. dicated a pair of closures 22 and 23 forming an air lock arrangement. Air lines 24 and 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 pur pose of simplifying the disclosure. The air lock Compartment defined by closures 22 and 23 con tains a swinging boom type of hoist 27 for use in removing dirt and material from the lower compartment according to well known "sand hogging' practice. The derrick O is installed by first placing it in an upright position with the open end of shell 3 resting on the underlying bed and then producing a depression thereunder and causing the struc ture 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 3 re 45 Sulting in the formation of an opening into which shell f3 is caused to be lowered. On the other hand this may be accomplished by carrying Out the usual "sand hogging' operations within the shell or caisson O. This consists essentially of maintaining a sufficient air pressure within the lower chamber to keep out the water while re moving the dirt from within and at the base of shell 3 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 10 s

4 cated in the upper portion of shell to the usual procedure. When the structure has been lowered to the desired depth, concrete 28 is poured into shell 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 39. Pipe 29 is maintained closed by a cover plate (not shown) until drilling operations are to be conducted therethrough. It may be neces sary to maintain the drilling chamber 2 under suitable pressure until drilling and "casing of' 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. The service barge 26 which is anchored adja cent the upper end of shell f, is also provided with a hoist or crane 3 for lowering the neces sary drilling equipment through the shell.. The service barge 26 may also carry the drilling mud, however, a separate mud barge may be em ployed. Mud delivery line 32 connects the mud supply on the barge with the swivel head 33 under the control of valve 34 while line 35 returns the mud overflow to the barge for settling and re conditioning before being returned, all in a man ner which is well known. In drilling a well through pipe 29 following the installation of drilling machinery within the drilling chamber 2, the first string of casing is introduced through closures 22 and 23 and low ered 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 2 is preferably placed under Sufficient 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 car rying the drill into pipe 29 and rotating the same by means of the rotary 5 while Supplying drill ing mud through line 32, following which the String of drilling pipe is removed and the first 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 at mosphere while the drilling is continued to the desired depth since there should be no further leakage after cementing in the first string of casing. It will thus appear that by extending tubular section of relatively small cross section to a point below the level of the wave action and providing an enlarged drilling chamber there below, a more stable and satisfactory arrange ment for drilling a subaqueous well is provided. In Figure 2 there is presented a modification of the arrangement of derrick and foundation shown in Figure 1. A tubular shell 50 is provided on its lower end with a conical or hemispherical portion 5 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 derrick 54 is composed in the usual manner of four legs 55 and bracing menbers 56. This structure is 70 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 57 adapted to be mounted above the water level when the structure is installed on according the underlying bed as shown. Bracket 58 on the upper portion of derrick 54 is adapted to receive the usual crown block such as block shown in Figure 1. The other drilling equipment includ ing the rotary, the draw works, etc., such as shown on work platform 8 of Figure 1, will be mounted on the work platform 57, 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 lock, closures 59 and 60 adapted to be connected with a supply of con pressed air on a barge anchored adjacent thereto for operation as in Figure 1. The structure is installed in position on the underlying bed in the same manner as in the case of the structure of Figure 1, which includes anchoring and sealing the base of shell 52 with concrete. In Figure 3 there is shown a still further modi fication of my invention wherein the usual form of derrick structure 75 such as that employed in Figure 2 comprising essentially four legs 76 fas tened together by bracing members 77. Each leg 76 is supportably attached on the upper end of an individual shell or caisson T8. Each of these shell or caisson supports is open at its lower end and provided with a cutting edge 79. Lines 80 connect with a suitable pump on a barge located as shown in Figure for pumping out the interior of the shells 78. Derrick 75 is provided with a work platform if located above the water level and 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 78 with their open ends resting on the underlying bed and removing the bed from within and at the base of the shells to form an opening and causing the respective shells to sink therein. This is effected by pumping out the water and suspended material through lines 80. Following this operation concrete is pumped into the shells 78 to anchor the same. The concrete may be in troduced through line 80 or where desired a sepa rate line (not shown) may be employed for this purpose. In Figure 4- there is shown schematically a modification of the improved method and ar rangement of apparatus of Figure 3. Foundation shell 00 corresponding to shell 78 in Figure 3 is surrounded by an auxiliary shell of open at both ends and of a slightly greater diameter than shell 00, thus defining 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 circ;ar area... directly under the shell preventing any Indency 'str;aunding to form a crater' in the his tigii; the shell. Figures 4a and 4b shown additional possible relative positions of the bottom edges of shells OO and?o depending upon the condition of the bottom.. 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 OO of Figure 4 is additionally provided with a guide 26 for cooperation-with a guide 27 for main taining the caisson in a vertical position while being installed. In shallow water particularly, guide 27 may take the form of a pile previously installed in the usual manner. A suitable seal 28 is provided to prevent pumping action through the guide opening 26 about the guide O s

5 27. This arrangement is of particular impor tance where the caissons are to be put down in dividually and the derrick later 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 re Sorted to within the scope of my invention with out 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 pro vided with a depending cylindrical shell open at its bottom and formed With a cutting edge, said enlarged lower portion defining a working cham ber wherein drilling operations are to be per formed, the upper portion of said caisson defin ing a passageway sufficiently large to permit of passage of workmen and tools and being pro vided 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 de pending cylindrical shell open at its bottom and formed with a cutting edge, the enlarged portion of the funnel defining a working chamber where in drilling operations are to be performed, the stem of the funnel defining a passageway Sufi ciently large to permit of comfortable passage of workman 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. 3. A derrick and foundation therefor for drill 3 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 enlarged lower portion, Said last-named portion being sunk into a depression in the underlying Water bed and filled at least partially with con Crete 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 tubu lar shell. 4. The method of installing a derrick for drill ing a well under the surface of a body of water which comprises attaching each leg of said der rick to a tubular shell open at its lower end, evacuating said shells to cause them to be low ered 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 drill ing 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 Sane. 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 pump 1?lg. 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. O 15