US2525955A

US2525955A - Apparatus for submarine drilling

Info

Publication number: US2525955A
Application number: US736289A
Authority: US
Inventors: Harold W Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-03-21
Filing date: 1947-03-21
Publication date: 1950-10-17
Anticipated expiration: 1967-10-17

Description

Oct. 17, 1950 H. w. SCOTT APPARA'IUS FOR sumuams DRILLING 2 Sheets-Shoat 1 F1104 March 21, 1947 IHH I 2 mo: wax.

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. W, 1950 H. w. SCOTT APPARATUS FOR SUBQIARINE DRILLING 2 Sheets-Sheet 2 Filed March 21. 194'! m m w. M

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Patented Oct. 17, 1950 UNITED STATES PATENT OFFICE APPARATUS DRILLING V I Harold W. Scott, Houston, Tex. Application March 21, 1947, Serial no. 136,239

1 Claim. (oral-46y 1 The present invention is directed 'to a submersible barge structure particularly adapted for drilling submarine wells.

For a number of years it has been the practice to drill submarine wells in the search for minerals and particularly for petroleum. By submarine drilling is meant the drilling ofa well in an area where the surface of the upper formation is covered with a body of water. Heretofore such submarine wells have either been drilled relatively clos to shore so that it has been practical to drive piles into the body of water for the purpose of supporting the derrick structure or in relatively shallow areas, such as in lakes or bays, where it has been practical. to employ drilling barges of such dimensions that the upper deck of the barge is above the water level when the' barge has been submerged so thatits bottom rests upon the surface of the formation forming vise a submersible barge structure adapted for,

drilling submarine wells. More particularly, it

is an object of the present invention to devise a submersible barge structure for drilling submarine wells under wind and wave conditions prevalent in open water such as in the Gulf of Mexico.

It is another object of the present invention to devise a method for lowering and raising a drilling barge structure under the windand water conditions which may be encountered in open water.

The device of the present invention may be described briefly as involving a submersible barge structure having pontoons or float chambers permanently attached thereto with the pontoons mechanically arranged to allow a maximum area of the pontoons to be exposed to the surface of the water as the barge structure is being lowered into position for drilling or as the barge structure is being raised after a drilling operation has been completed.

The method of the present invention may be described briefly as involving the maintenance of a substantially uniform force on pontoons or float chambers permanently structure may be lowered or raised at a substantially uniform rate and the stability thereof maintained. a

The present invention will now be described in greater detail in connection with the drawing which illustrates one embodiment of the device of the present invention and in which Fig. l is in the formof an elevation;

Fig. 2 is a view along line IIII of Fig. 1,

Fig. 3 is a top view of the apparatus of Fig. 1 with conventional parts of the drilling equipment removed to show more clearly the feature of the'present invention, and

Fig. 4 is a fragmentary view showing a portion of the apparatus of Figs. 1 and 3 in greater detail.

Turning now specifically to the drawing, it will be seen that the device includes two hulls i l' and Ila which are laterally spaced. Mounted on hull II at spaced intervals are tubular structural members I3 and similarly tubular structural members I3a are mounted on hull member Ila at spaced intervals. It will be understood that hull members II and Ila may be identical and tubular members 13 and [3a may be identical but are designated differently in order to explain the connection of the structure.

The assembly H and I3 comprising one hull structure and the assembly Ila and lBa com prising the other hull structure are connected together by a connecting truss structure It. The upper portion of tubular members [3 and I311 andconnecting truss l4 serve to support a deck l5 upon which may be mounted the conventional equipment employed for drilling wells such as derrick I6, engine house 11, mud tanks l8, pipe rack l9 above the mud tanks and a power plant 20. It will be understood that the conventional drilling equipment, such as the derrick, engine house, mud tanks, pipe rack and power plant are shown in simplified form since these pieces of equipment are well known to the art. It will be understood that various other pieces of drilling equipment, such as draw-works, rotary table and the like, which are customary for the rotary drilling operations of wells generally, will be provided.

It is to be pointed out that the hulls l I and Na are designed to be completely submerged when the apparatus is in position for drilling. It is well-known to those versed in the art that when the hull structures H and Ila are completely submerged, there is no way to use these hulls attached to a submersible drilling barge structure whereby the to control the downward movement of the structure before the bottoms of the hulls come into contact with the bottom upon which the structure is to rest. According to the present invention, means is provided for controlling the downward movement of the structure after the upper surfaces of hulls II and Ho are covered with water.

In accordance with the present invention, a pair of pontoons 2| and 2|a are provided. The longitudinal axis of pontoon 2| is arranged parallel to the longitudinal axis of hull H and the longitudinal axis of pontoon 2 la is arranged parallel to the longitudinal axis of hull Ila. A plurality of levers 22 is provided with one end of each lever 22 attached to pontoon 2| and the other end of each lever pivoted to a member l3 by suitable means which may include, for example, a hinge member 23 with a pin 24 passing through a laterally extending opening in the end of lever arm 22. Pontoon 2|a is similarly secured to hull structure U by lever arms 22a and hinge members 23a, with each lever arm 22a secured by a hinge member to a column |3a. Each hinge member 23a includes a pin 24a passing through a suitable opening 25a in arm 22a.

For convenience the barge structure heretofore described and including the twin hulls H and Ila, columns l3 and |3a and connecting truss M will be termed a submersible barge structure. When this structure is being submerged or raised, its stability is controlled by hydraulic means mechanically secured to pontoons 2| and 2|a. In the embodiment shown, the hydraulic means comprises a plurality of assemblies A. An assembly A is operably connected to each of lever arms 22 and 22a. Assembly A includes cylinder 26 with piston 21 slidably arranged thereon and connected to a piston rod 28 which slidably extends through a suitable opening in the head 23 with which cylinder 24 is provided. The end of pistcn rod 26 which extends outside cylinder 24 is bifurcated and through the bifurcated portions holes are drilled to receive a suitable pin or bolt 30.

Each hydraulic assembly A is supported by a pair of structural members. The pairs of structural members mounted on hull II are designated as 3 I, 32 and those mounted on hull ||a are designated as 3|a and 32a. It will be seen that each pair of structural members 3|, 32 is similar to a supporting column l3 but with the center portion removed. Mounted between each pair of members 3|, 32 is a hydraulic assembly A. Cylinder 26 of the hydraulic assembly is provided with trunnions 33 which are mounted unsuitable bearing members 34 attached to structural members 3| and 32.

Pairs of structural members 3|a and 32a mounted on hull l are similar to structural members 3|, 32 with each pair of members 3|a, 3211 having a hydraulic assembly A mounted thereon with the trunnions 33a the hydraulic member supported by bearings 34a secured to structural members 3 |a and 32a.

Columns |3, 36, 3|, and I3a, 30a. and 3|a being water-tight cause the d'splacement of the structure to increase as the barge is submerged which will aid in controlling the rate of descent. It will be noted that members l3 and each pair of structural members 3|, 32 are arranged to provide a support for a single lever 22 with the end of the lever plvovd t-- member I3 and sideways movement of the lever limited by the adjacent walls oi members "4 '2. Mmb r l3 and the pair of members 3|, 32 are designed to provide a sub- 4 stantlal cylindrical surface to reduce the resistance to wave action. Barge ||a is similarly provided with structural means |3a, 3|a, and 32a with these members grouped so that each member |3a with adiacent members 3|a, 32a provide a mounting means for a single lever 22a for the same purposes as heretofore described with respect to members I3, 3| and 32.

It will be understood that the cylinder 34 of each assembly A will have a suitable fiuid therein, such as oil. The hydraulic members A mounted on hull II are fluidly connected, as through a line 35, by a suitable means, such as a connection 33 discharging through one of trunnions 32, which is made hollow for this purpose, into cylinder 23. Line 35 has arranged therein a pump 31 which discharges into a suitable storage tank 33. A line 33 by-passes pump 31 and has arranged thereon a suitable valve, such as a spring loaded relief valve 40. A valve 4| may be mounted adjacent pump 31. Similarly, hull ||a is provided with a line 35a connected through connecting lines 36a to the cylinders of assemblies A. Line 35 discharges into storage tank 38a and has pump 31a arranged therein. Line 39a by-passes pump 36a and has valve 40a arranged therein and a valve 4|a is arranged in line 35 adjacent pump 31a.

Barge hull H is provided with a suitable valve or sea cook 42 to allow water to flow into the hull when submerging it and, similarly, hull ||a is provided with valve or sea cock 42a. It will be understood that valves for flooding submersible barges are well known to the art and details of construction of these valves will not be given in order to simplify the description of the present invention. A vent 43 is provided between hull II and columns |3 to allow air to be discharged from the hull into the columns and the upper ends of the columns are provided with an outlet 44 controlled by valve 45. Similarly, hull I la is provided with a vent 43a allowing discharge from the hull to columns |3a and the upper ends of columns |3a are provided with outlet 44a controlled by valve 45a.

When it is desired to lower or submerge the structure, as when the barge has been towed to the location at which a well is to be drilled, the sea cocks 42 and 42a may be opened and with valves 45 and 45a open water enters hulls I and Na and air is discharged through

outlet lines

44 and 44a. As water floods the hulls II and Ila, the structure will gradually sink in the water while pontoons 2| and 2|a are maintained full of air and will float at the surface. In order to achieve maximum effectiveness from the pontoom, it is desirable that they be submerged to substantially one-half their depth in water so that the maximum area is in contact with the surface of the water.

As the hulls I and Ho sink, pontoons 2| and 2|a will be maintained at the surface by movement of levers 22 and 22a. The rate at which the structure settles in the water may be regulated by controlling the hydraulic pressure above the pistons in assemblies A. This pressure may conveniently be maintained by closing valve 4| and setting relief valve 40 to open at a predetermined pressure in the hydraulic system of hull H and closing valve 40a and setting relief valve 43a to operate at said predetermined pressure in the hydraulic system of hull No. It will be understood that the relief valves 43 and 4041 will keep a uniform pressure in the hydraulic assembliee A and thereby stabilize the structure and keep it on an even keel as it is submerged.

When the bulls II and Ha rest on the bottom it will usually be unnecessary to employ the pontoons 2i and Ma for stabilization purposes and the pontoons may then be filled with water and allowed to assume the position indicated by solid lines in Fig. 2. The position of the pontoons as the structure is being lowered is indicated by dotted lines in Fig. 2 with the water level at the time the device is being lowered indicated by the line designated by the legend WL.

It will be understood that when the structure is being raised to the surface, the pontoons may be utilized in a similar manner to stabilize the structure and keep it on an even keel. When the structure is being raised, it will be understood that a substantially uniform pressure must be maintained in the cylinders of hydraulic assemblies A and, accordingly, it is desirable to operate pumps 3? and 31a. In other words. valves ti and tic may be opened and pumps 37 and 37a started up and allowed to operate continuously: if the pumps exert more than a predetermined pressure the relief valves will operate and allow part of the output of the pumps 3! and 31a to flow through the by-pass lines 39 and 39a, respectlvely. It will be understood that in order to raise the assembly, some means must be provided for forcing water out o! hulls ii and i to. Specific means for accomplishing this purpose are well known to the art and in order to simplify the drawing details of such arrangements are not shown. It may be stated, for example, that ejector means may be provided for withdrawing water through sea cocks 42 and Ma or air pressure ma be used by connecting a suitable source of supply of compressed air to outlet M and Ma. Irrespective of the means employed for forcing the water from the bulls H and Ho, the uniform pressure exerted through

lines

35 and 35a on the hydraulic assemblies A will cause the iii pontoons 2i and am to exert a stabilizing effect on the structure and keep it on an even keel as it rises to the surface of the water.

It will be understood that it is not essential in the practice of the present invention to employ automatic relief valves 40 and 40a for controlling the pressure on the hydraulic system. It will be evident that manually operated valves may be employed and pressure gauges provided in the system whereby an operator may manipulate the manuall controlled valves to maintain a substantially constant pressure as indicated by the pressure gauges. It will also be obvious that other hydraulic arrangements may be employed which will allow the maintenance of a substantially uniform pressure on the hydraulic assem- While a specific embodiment of the present invention has been described. it will be apparent to a workman skilled in the art that various changes may be made without departing from the scope or the invention.

Having fully described and illustrated the present invention, what is desired to be claimed as new and useful and to be secured by Letters Patent is:

A device adapted for drilling submarine oil wells comprising a barge structure having laterally spaced hulls, a plurality of tubular structural members symmetrically spaced along each of the said hulls with the lower ends thereof secured to the hulls, structural members securing the tubular members together to form a unitary structure, a first pontoon and a second pontoon arranged parallel, with each pontoon adjacent an outside edge of a hull, a iirst plurality of lever arms with each arm having an end secured to a pontoon and the other end pivoted to a tubular member next adjacent the first pontoon, a second plurality of lever arms with each end connected to the second pontoon and the other end pivoted to the tubular member next adjacent said second pontoon, and hydraulic control for controlling the arcuate movement of said first plurality of lever arms, means mechanically connected to said first plurality of lever arms and second hydraulic control means for controlling the arcuate movement oi said second plurality of lever arms mechanically connected to said second plurality of lever arms, each hydraulic control means including a valve for controlling the pressure therein.

HAROLD W. SCOTT.

REFERENCES CITED The following references are of record in the tile 01 this patent:

UNITED STATES PATENTS Number Name Date 123,402 Janicki Feb. 6, 1872 1,316,357 Cook Sept. 16, 1919 1,883,276 Woods Sept. 4, 1928 1,681,533 Giliasso Aug. 21, 1928 1,918,426 Radnor July 18, 1933 FOREIGN PATENTS Number Country Date 514 Great Britain Feb. 11, 1875 837,730 France Nov. 18, 1938