US3618661A

US3618661A - Apparatus and method for drilling and producing multiple underwater wells

Info

Publication number: US3618661A
Application number: US850463A
Authority: US
Inventors: Charles P Peterman
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1969-08-15
Filing date: 1969-08-15
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09

Abstract

Apparatus and method for drilling and producing multiple underwater wells wherein drilling and production template means is remotely lowered and installed at an underwater location. The template means comprises a plate having a plurality of holes therein through which underwater well drilling operations may be carried out. A plurality of guideposts on the template means and guidelines associated therewith are utilized to lower into position the various drilling and production components operatively associated with each of the wells.

Description

PATENTEUunv 9 mm SHEET 1 BF 9 FIG.

INVENTOR:

C. P. PETERMAN BY".

HIS ATTORNEY I United States Patent H 1 3,618,661

[72] Inventor Charles P. Peterman 3,221,506 12/1965 Stratton et al. 175/7 X Houston, Tex. 3,366,173 l/l968 McIntosh 166/5 [21] Appl. No. 850,463 3,380,520 4/1968 Pease 166/.5 [22] Filed Aug. 15, 1969 3,492,027 1/1970 Herring 166/.6 X [45] Patented Nov. 9, 1971 3,504,740 4/1970 Manning 166/.5 [73] Assignee Shell Oil Company 3,504,741 4/1970. Baker et a1 166/.5

New York, N.\'.

[54] APPARATUS AND METHOD FOR DRILLING AND PRODUCING MULTIPLE UNDERWATER WELLS 11 Claims, 17 Drawing'l igs.

[52] U.S. Cl 166/.5, 175/7 [51] Int. Cl. E2lb7/l2 [50] Fieldolseareh 166/.5, .6;

[56] References Cited UNITED STATES PATENTS Primary Examiner-Marvin A. Champion Assistant Examiner-Richard E. Favreau Attorneys-Thomas R. Lampe and J. H. McCarthy ABSTRACT: Apparatus and method for drilling and producing multiple underwater wells wherein drilling and production template means is remotely lowered and installed at an underwater location. The template means comprises a plate having a plurality of holes therein through which underwater well drilling operations may be carried out. A plurality of guideposts on the template means and guidelines associated therewith are utilized to lower into position the various drilling and production components operatively associated with each of the wells.

INVENTOR C. P. PETERMAN BY /Z HIS ATTORNEY PATENTEUNuv 9 Ian SHEET 3 [IF 9 INVENTOR:

C. P. PETERMAN HIS ATTORNEY FIG. 5

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FIG. 6

INVENTOR:

C. P. PETERMAN HIS ATTORNEY PATENTEDunv 9 ml SHEET 5 [IF 9 FIGS INVENTOR FIG. 9

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sum 9 or 9 FIG. l5

INVENTOR C. R PETERMAN HIS ATTORNEY APPARATUS AND METHOD FOR DRILLING AND PRODUCING MULTIPLE UNDERWATER WELLS This invention relates to a method and equipment concerned with drilling, producing andother operations relating to underwater wells and pertains more particularly to a method and apparatus whereby a plurality of underwater wells may be conveniently and efficiently drilled through a single template means and wherein the same template means may be used as a base whereby modular production components may be placed into operative association with the various drilled wells.

In an attempt to locate new oil fields, an increasing amount of well drilling has been conducted at offshore locations, such for example as off the coast of California, Louisiana and Texas, and, more recently, off the coast of Alaska and in the North Sea. As a general rule, the string of casing in a well, together with the tubing string or strings, extend to a point above the surface of the water where they are enclosed in a conventional manner that is used in onshore wells, with a conventional wellhead assembly being attached to the top of the casing. Recently, methods and apparatus have been provided for drilling and completing the well, wherein both the well and casing head and consequently the wellhead assembly andcasing closure device are located underwater at a depth sufi'lcient to allow ships to pass over them.

Underwater equipment of this latter type is quite expensive and the installation thereof in operative association with the underwater well is also an expensive and time-consuming matter. Such cost and time considerations become especially important when operations are carried out in highly developed fields with a number of wells. It is to be understood that in these highly developed fields, each of the wells in the field has associated therewith an underwater wellhead assembly and associated equipment whereby the well may be produced in the customary manner. Flow lines run from each of the wells to a suitable production facility which may be either onshore, above the surface of the water as by means of a platform or floating vessel, or disposed on the seabed itself. In any event, it may be appreciated that installation and maintenance of this equipment with respect to each individual well is a time-consuming and expensive proposition. Each well, of course, must have associated therewith suitable control means for controlling operation and production of the well, as well as specialized equipment whereby workover, maintenance or other operations with respect to the well may be carried out from a remote location. The incorporation of these latter features, of course, also add to the overall expense involved with respect to each well.

SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide an apparatus and method whereby drilling and production operations with respect to a plurality of underwater wells may be economically carried out in a relatively short period of time.

A further object of the present invention is to provide an apparatus and method whereby a plurality of underwater wells may be drilled and completed from a centralized location, and wherein production equipment may be readily brought into operative association with the plurality of wells at this locatron.

These and other objects have been attained in the present invention by providing a method and apparatus wherein a template means including a baseplate is lowered into position on the ocean floor and fixed securely thereto. A plurality of apertures are formed in the baseplate through which a multiplicity of wells may be drilled. Guide columns extend upwardly from the baseplate and are disposed in such a manner as to permit drilling and production equipment to be lowered onto the baseplate and in operative association with the various wells. The production equipment includes a manifolding arrangement adapted to receive production fluid from each of the wells, from whence the fluid is delivered to suitable flow lines to a desired location. Wellhead control with respect to each individual well may be had through suitable control means which is positionable on the baseplate and placed into operative engagement with the various wells.

DESCRIPTION OF THE-DRAWING Other objects, purposes and characteristic features of the present invention will be obvious from the accompanying drawing and from the following description of the invention. In describing the invention in detail, reference will be made to the accompanying drawing in which like reference numerals designate corresponding parts throughout several views and in which:

FIG. 1 is an isometric view illustrating the template means of the present invention being lowered from a floating vessel and prior to its installation on the ocean floor;

FIG. 2 is an isometric partial view illustrating a portion of the template means in cooperation with a tool which is used to affix a guideline to an upstanding guidepost on the template means;

FIG. 3 is an isometric view illustrating a drill pipe and bit being lowered into position over the template means and prior to the drilling operation;

FIG. 4 is an isometric view illustrating well casing being lowered into operative association with one of the apertures of the template means;

FIG. 4A is a cross-sectional view of the casing lowering equipment;

FIG. 5 is an isometric view illustrating a casing and wellhead in operative association with the template means and one of the plurality of wells;

FIG. 6 is an isometric view illustrating a drilling wellhead assembly being lowered into position upon the template means and into operative association with a well casing and wellhead which previously have been installed;

FIG. 7 is a schematic view illustrating a wellhead assembly being lowered into an alternative position with respect to the template means;

FIG. 8 is an isometric view illustrating the template means according to the present invention with casing and wellhead means disposed in association with all four apertures of the template means baseplate;

FIG. 9 is an isometric view illustrating the installation of a manifold means into cooperative engagement with all four walls associated with the template means;

FIG. 10 is an isometric view illustrating the manifold means shown in FIG. 9 in operative position on the template means baseplate;

FIG. 11 is an isometric view illustrating the flow line horns in operative engagement with the manifold means and template means with flow lines running from the flow line horns;

FIG. 12 is an isometric view illustrating the lowering of a production wellhead assembly along guideline means through the use of a running frame adapted for this purpose;

FIG. 13 is an isometric view illustrating the running frame shown in FIG. 12 being retrieved from the ocean floor after the production wellhead assembly has been positioned;

FIG. 14 is an isometric view illustrating all four production wellhead assemblies in position with a control package being lowered thereupon;

FIG. 15 is an exploded isometric view illustrating details of a production wellhead assembly; and

FIG. 16 is a diagrammatic isometric view illustrating a detail of the control package.

Referring now to FIG. 1 of the drawing, a vessel or floating platform 11 is shown at the surface of a body of water 12 and substantially fixedly positioned at a preselected location by suitable vessel positioning means, or by being anchored to the seabed or ocean floor 13 by suitable anchor means (not shown). Equipment of this type may be used when carrying on operations with respect to wells positioned from to 3,000 feet or more underwater. Vessel II is equipped with a suitable derrick 14 as well as other conventional auxiliary equipment such as a hoist system (not shown) etc. Derrick 14 is positioned on a platform 15 extending out over the side of the vessel 11. Operations are carried out through suitable aperture means formed in platform 15. Alternatively, the derrick 14 may be positioned over a drilling slot or well extending vertically through vessel 11, with the slot in the vessel being either centrally located or extending in from one edge thereof. Depending from derrick 14 on board vessel 11 is the drill string 16 having a drill bit 17 and reamer 18 attached to the dependent end of the string. Also depending from vessel 11 is a marine conductor 19 which surrounds drill string 16 throughout the major length thereof. Further depending from vessel 11 are

guidelines

20, 21, and 22 which are connected to constant tension hoists (not shown) on board vessel 11.

Marine conductor 19 is connected as its lowermost end by means of a suitable connector 23 to a template means which is indicated generally by means of reference numeral 24. Template means 24 includes a baseplate 25 having a plurality of

apertures

26, 27, 28 and 29, which are formed in the respective four corners of the baseplate which as illustrated has a square configuration. It should be understood, however, that the baseplate may have any suitable configuration such as rectangular or triangular for example. Extending upwardly about the periphery of baseplate 25 are a plurality of guidepost elements 30a-30h. A central throughbore 31 is formed in the baseplate 25 which accommodates a tubular support post 32 with the top portion of the support post being engaged by connector 23 and the major extent of the support post projecting downwardly from the bottom of baseplate 25. It is to be understood that tubular support post 32 is fixedly secured to baseplate 25 by any known expedient, such as by being welded thereto.

In operation, template means 24 is lowered from vessel 11 by means of marine conductor [9. During the lowering operation, the template means 24 is disposed about drill string 16 with tubular support post 32 also surrounding the drill string as illustrated. The lowering operation is temporarily terminated before tubular support post 32 reaches seabed I3 with the marine conductor 19 supporting the template means in this position. While such position is maintained, drill string 16 is rotated with drill bit 17 and reamer 18 forming a foundation pile hole 33 in seabed 13. After foundation pile hole 33 has been drilled to a length less than that of the portion of tubular support post 32 extending downwardly from baseplate 25, the drilling operation is terminated. At that point, template means 24 is lowered by means of marine conductor 19 so that tubular support post 32 enters into foundation pile hole 33. Due to the action of reamer 18, the internal diameter of foundation pile hole 33 is somewhat larger than the external diameter of tubular support post 32. Other techniques may of course be used to install the support post. For example, such unit may be jetted into position by using a short drive pipe in the well known manner and then drilling out to accommodate the main pile or post. After tubular support post 32 has been seated in position within the hole 33 so that a portion of the support post remains above seabed 13 (as shown in FIG. 3, for example) cement is pumped from vessel 11 down through drill string 16 so that the cement passes through the bottom of drill bit 17 and flows upwardly into the annulus formed between tubular support post 32 and foundation pile hole 33. Pumping of the cement continues until it flows out of the annulus above seabed 13, as shown by means of reference numeral 34 in FIG. 3. Connector 23 is then disengaged from tubular support post 32 and the marine conductor 19 and drill string 16 are retrieved to vessel 11. Upon hardening of the cement, template means 24 is firmly anchored into position with baseplate 25 remaining a predetermined, fixed distance above the seabed 13, as shown in FIG. 3.

After template means 24 has been cemented into position, a latching tool 35 (FIG. 2) is lowered from vessel 11 in the direction of Arrow A along

guidelines

20, 21 and 22. Tool 35 includes a central element 36 defining a throughbore 37. A

plurality of arms 38a-38d are fixedly disposed about the periphery of central element 36 and extend radially outwardly therefrom, as shown in FIG. 2. Arms 38a-38d have fixedly disposed at the respective outer ends thereof tubular guide members 39a-39d. A pair of

wires

40 and 41 are utilized to lower tool 35 in the direction of Arrow A with the wires, of course, extending to vessel ill in an obvious manner. During this lowering operation, stability is provided to tool 35 due to the fact that

tubular guide members

39a, 39b and

39d surround guidelines

20, 21 and 22. Tubular guide member 39:, on the other hand, has disposed therein by means of any suitable latching arrangement, a guidepost 42 which has a guideline 43 extending upwardly from the top thereof to vessel 11, and a connector element 44 disposed at the lower end thereof. Due to the interaction between

tubular guide members

39a, 39b and 39d, and

guidelines

20, 21 and 22, the connector element 44 is automatically positioned over tubular support post 32 during the lowering of tool 35. Lowering of tool 35 continues until connector element 44 is engaged with tubular support post 32 and is latched thereto by means of any suitable mechanism. Tubular guide member 39c is then disengaged from guidepost 42 and tool 35 is retrieved to vessel 11 by means of

wires

40 and 41, thus leaving the connector element 44, guidepost 42 and guideline 43 in operative association with template means 24, as shown in FIG. 3. It should be noted at this point that a fourth guide line may not be necessary to carry out the teachings of the present invention since three guidelines, if properly spaced and tensioned will be adequate in many cases.

In carrying out the method accordingly to the present invention, the next step is to lower a drill string 45 and rotary bit 46 in the manner illustrated in FIG. 3. The drill string and bit are lowered from vessel 11 in the usual fashion, i.e., by lengthening the drill string through the addition of individual pipe sections. To insure the proper position of the drill string and rotary bit, tool 35 is lowered along with the string and bit, with the string positioned within throughbore 37 of central element 36. Tubular guide members 39a39d cooperate with

guidelines

20, 21, 22, and 43 to maintain the drill string in the desired location. As tool 35 reaches the vicinity of

guideposts

30b, 30c, 30d and 42, the tubular guide members pass over the guideposts and bit 46 enters aperture 26 which is formed in baseplate 25 of the template means. After rotary bit 46 has engaged sea floor 13, the string and bit are rotated to spud a well in the ocean floor. After a wellhole has been drilled to a desired depth, tool 35, along with drill string 45 and rotary bit 46 are withdrawn to vessel 11.

FIG. 4 illustrates the next step in carrying out the method according to the present invention. Shown being lowered from vessel 11 by means of a running and cementing pipe string 47 is a length of well casing 48. Well casing 48 is positioned within throughbore 37 of the tool 35 central element to maintain the casing in a vertical position with the casing located above aperture 26 in baseplate 25. The well casing 38 is gradually lowered by means of running string 47 and tool 35 is lowered at a like rate of speed in a manner previously described with respect to a drill string and rotary bit. This lowering operation continues until the tubular guide member of tool 35 passes over the respective guideposts in the manner previously described and the bull plug 49 disposed over the end of casing 48 enters into aperture 26 and thence into the well borehole 50 formed in the ocean floor 13 during the previously described drilling operation. Final termination of the lowering of casing 48 occurs when an integrally formed hanger element 51 about the periphery of casing 48 contacts the portion of baseplate 25 immediately surrounding aperture 26. At this point, the major extent of the well casing will be suspending within borehole 50 with the remainder of the easing extending upwardly and through aperture 26 to the top of baseplate 25. Cement is then pumped from vessel 11 down running and cementing pipestring 47 and thence downwardly through the interior of casing 48 into well borehole 50. The cement then flows upwardly into the annulus formed between borehole 50 and casing 48 so that the casing is cemented into position within the borehole in the usual manner. Running and cementing pipestring 47 is then retrieved to vessel 11. FIG. 4A shows a detail of the running string 47 and casing 48 in the cooperative relationship maintained between the two elements during the lowering operation. A J-slot 52 is formed on the periphery of casing 48 near the upper end thereof. Running and cementing pipestring 47 has an enlarged head 53 disposed at the lowermost end thereof with said head having a radially outwardly projecting pin member 54 which cooperates with .l-slot 52 in the manner illustrated. When the pin member 54 is positioned within the terminal portion of L slot 52, support is provided for casing 48 by string 47 in an obvious manner. After the casing 48 has been suitably positioned with respect to baseplate 25, running and cementing pipestring 47 is depressed and rotated slightly so that pin member 54 is positioned in the long branch of the J-slot. By then pulling the running and cementing pipestring 47 in an upwardly direction, pin 54 and consequently the remainder of the running and cementing pipestring may be freely drawn upwardly and out of engagement with casing 48. FIG. 5 illustrates the respective positions assumed by the various elements of the present invention after casing 48 has been cemented into position and tool 35 as well as running and cementing pipestring 47 have been retrieved to vessel 11.

The next step to be performed is the lowering of an underwater drilling wellhead assembly into operative association with casing 48. This step is illustrated in FIG. 6 wherein a drilling assembly which may be of any suitable construction is designated generally by means of reference numeral 55. The drilling assembly includes a wellhead conductor 56, as well as other conventional drilling assembly components such as blowout preventors 57 and 58. Since drilling assembly 55 may be of any suitable construction and such equipment is well known in the art, it is not deemed necessary to describe this piece of equipment in greater detail. However, it is a requirement that suitable guide means be employed to insure the correct positioning of the drilling assembly. In this regard, drilling assembly 55 is shown as being provided with a plurality of arms such as

arms

59 and 60, which have disposed at the outer ends thereof suitable guide elements which cooperate with

guidelines

20, 21, 22 and 42 as well as their respective guideposts so that proper positioning of drilling assembly 55 is maintained at all times. It is, of course, to be understood that lowering of drilling assembly 55 continues until wellhead connector 56 latches into engagement with wellhead 59 comprising an extension of well casing 48. Supporting drilling assembly 55 during the course of its downward movement is a marine conductor pipe 60 and a drillpipe 61 which extend upwardly to vessel 11. After the drilling assembly has been latched into position, drill pipe 6] as well as the drill bit (not shown) operatively associated therewith, extends downwardly into casing 48 so that the well-drilling operation may be completed.

In FIG. 7 an attempt has been made to illustrate in schematic fashion the fact that the operations being carried out with respect to a well disposed under aperture 26 may also be carried out with respect to the other three apertures, i.e.,

apertures

27, 28 and 29, by merely changing the guidelines to alternative guideposts on baseplate 25. For example, to carry out operations through aperture 27, the guidelines are connected to

guideposts

30d, 30e, 30f and 42 so that various equipment, such as drilling assembly 55 will be correctly posi tioned to carry out operations in this alternate location. Guideline switching may be achieved, for example, by moving each line separately using a drill pipe and hydraulic jet technique, or, alternately, a special frame may be utilized to simultaneously release and reset all four guidelines as desired.

Referring now to FIG. 8, template means 24 is shown with all four aperture means thereof in operative association with a completed well. Such wells were completed in precisely the same manner as that described with respect to the well operatively associated with aperture 26 of the template means. Ac-

cordingly, four wellheads, i.e.,

wellheads

59, 62, 63 and 64, are disposed about baseplate 25. In addition, the guidelines utilized during the preceding operations have been withdrawn to vessel 11 until they are needed for further operations.

After the drilling operations have ceased and all four wells operatively associated with the template means 24 have been completed, a manifold module, indicated generally by means of reference numeral 65 in FIG. 9, is lowered into position on baseplate 25. Essentially, manifold module 65 comprises a plurality of doughnut-shaped

members

66, 67, 68 and 69, which are adapted to index around wellheads 59, 62, 63 and 64, respectively.

Members

66, 67, 68 and 69 are operatively associated with manifold piping 70 which is adapted to be connected to flowlines in a manner to be described below through

flowline connectors

71, 72, 73 and 74. Each of the doughnutshaped members is provided with a plurality of stabs, such as

stabs

75, 76, 77 and 78, illustrated with respect to doughnutshaped member 68, for example. The stabs are in communication with the manifold piping 70 so that fluid flow paths are established through the doughnut-shaped members.

The doughnut-shaped members rest on a running

frame comprising arms

79, 80 and 81 and a central connector element 82 defining a throughbore 83 in such a manner that

members

66, 67, 68 and 69 are not restrained from indexing around each

wellhead

59, 62, 63 and 64. The manifold piping 70 should be sufficiently flexible to allow

members

66, 67 68 and 69 enough freedom of movement to accommodate the maximum amount of misalignment expected between the wellheads.

Extending through throughbore 83 is a guideline 84 which has previously been secured to a guide post 42 by any known expedient. Manifold module 65 is lowered along guide line 84 from vessel 11 by means of a running string 85 which is releasably secured in any known manner to central connector element 82. It will be appreciated that when a single guideline such as guideline 84 is used to guide the manifold module into position, that the manifold module will be free to rotate around. Accordingly, it is desirable to have an auxiliary means to assist in the proper placement of the manifold module upon baseplate 25.

FIG. 9 illustrates one arrangement which may be used for the purpose of assisting a proper placement of manifold module 65. In that figure, a television camera 86 is shown as being pivotally mounted upon a running frame 87 which is lowerable along

guidelines

88 and 89 which have previously been secured to guideposts 30a and 30d. The TV camera is operatively associated with a conduit or cable 90 which extends upwardly through vessel 11 and is used to control the lowering of the running frame 87 as well as to monitor the placement of manifold module 65. Of course, numerous other expedients may be utilized to insure the proper placement of the manifold module with respect to the remainder of the equipment. For example, the manifold module may have extending therefrom guide elements which would cooperate with a plurality of guidelines to prevent rotational movement of the manifold module. The lowering of the manifold module continues until this piece of equipment is in the position illustrated in FIG. 10 with the doughnut-shaped

members

66, 67, 68 and 69 disposed about the

wellheads

59, 62, 63 and 64. It is, of course, to be understood that the running string 85 has been previously disconnected from central connector element 82 and removed to vessel 11.

In FIG. 11 a plurality of conventional

flow line horns

92, 94, and 96 are shown as being in position upon baseplate 25 and disposed at the ends of

flow line connectors

71, 72, 73 and 74. It will be assumed that

flow line horns

93, 94, 95 and 96 have been previously lowered into position upon baseplate 25 through the use of any conventional running technique, so that the flow line horns are mounted upon mounting

elements

97, 98, 99 and I00 which are integrally attached to baseplate 25 as shown in FIG. 10, for example. The flow line horns are shown as having attached thereto and in operative association with

flow line connectors

71, 72, 73 and 74 a plurality of

flow lines

110, 1111, 112 and 1113 with the flow lines terminating at their respective outer ends (not shown) at the suitable production facility located either onshore or ofl'shore with said offshore facility being either above or below the water. Since flow line connecting methods are well known in the art, it is not deemed necessary to discuss such procedure in great detail. One feasible approach for accomplishing this may be to utilize the pull tube method to connect the lines. In this method, the flow lines are pulled and locked into place in the flow line horns by means of a cable or other similar means. The flaring outer portion of the horns assist in guiding the flow lines into position. The pull tube" approach is disclosed more fully in U.S. Pat. No. 3,358,753, issued Dec. 19, 1967 to .l. A. I-Iaeber, and reference may be made to that patent for more details concerning methods and apparatus of this type.

The next step to be carried out according to the teachings of the present invention is the placement of production wellhead assemblies into operative association with the previously installed equipment with one underwater production assembly being disposed on each of the doughnut-shaped members. In FIG. 12, one such production wellhead assembly 114 is shown as being lowered into position in the direction of Arrow B, by means of a wellhead assembly running frame 115. The wellhead assembly or production control unit 114 is adapted to be placed into fluid communication with the production tubing associated with each well, and comprises the necessary piping, valves, chokes, and other equipment normally connected together and mounted on the top of a well, and known as a Christmas tree" together with the necessary hydraulic or electrical system, including pumps, reservoirs, motors, etc. to operate the valves at the head of the well from a remote location. The wellhead assembly further includes means (not shown) for receiving the stabs of the cooperating doughnutshaped member, so that fluid flow may be established between the wellhead assembly and manifold 70. Wellhead assemblies are generally well known in the prior art and a typical example of an underwater production control unit or wellhead assembly for use at an offshore location, and its manner of operation, is shown and described in U.S. Pat. No. 3,064,735, issued Nov. 20, 1962 to R. J. Bauer et al. Wellhead assembly 114 is held within running frame 115 by any suitable latch means during the lowering operation. The running frame itself includes upper and lower cylindrically shaped

housing elements

116 and 117 which are adapted to accommodate the production wellhead assembly in the manner illustrated. The housing elements are frame-connected so that they are in alignment, thus insuring the proper positioning of wellhead assembly 114 therein. Secured to

housing elements

116 and 117 in any desired manner are elongated running

tubes

118, 119, 120 and 121, which cooperate with

guidelines

122, 123, 124 and 125 to insure the desired positioning of the wellhead assem bly 114 and running frame 115 during the lowering operation.

Guidelines

122, 123, I24 and 125, of course, extend downwardly to four selected guideposts on the template means baseplate 25 and upwardly to vessel 11. The guidelines are secured to the guidepost means through use of conventional guideline attaching equipment. After the production wellhead assembly 114 has been lowered into position with respect to the previously installed equipment, wellhead assembly running frame 115 is retrieved back to vessel 11 along the guidelines in the direction of Arrow C in FIG. 13. The above-described lowering and retrieving operations with respect to the wellhead assembly and the running frame are effected through the use of a running string 126 which is secured to wellhead assembly running frame 115 by any desired connector means 127.

As previously stated, one production wellhead assembly is to be associated with each of the wells drilled into the ocean floor through the template means 24. In FIG. 14 it will be assumed that four such wells have been drilled and that four production wellhead assemblies, i.e.

assemblies

114, 128, 129, and 130 have been placed into position by means of running frame 115. It should be noted that the weight of each wellhead assembly is supported by its own well casing or pile member. Accordingly, the baseplate 25 is not subjected to any undue strain upon the positioning of the production wellhead assemblies thereon.

As shown in FIG. 15, each production wellhead assembly may be comprised of a plurality of sections which will facilitate the repair of each wellhead assembly in the event of operational failure thereof. For example, the illustrated production wellhead assembly may include a process valve manifold 140, a control package contains pilot operated hydraulic valves 141, and a connector cap 142. These various components are connected together in an operative manner by means of suitable hydraulic or electrical stabs or connectors, such as

connectors

143, 144, and 145. The valve manifold portions of the wellhead assemblies incorporate suitable receptacles (not shown) which cooperate with the hydraulic or electrical stabs, such as

stabs

75, 76, 77 and 78 operatively associated with doughnut-shaped member 68 (FIG. 9).

After the wellhead assemblies have been placed in position in the manner previously described, a four-well control pod 151 (FIG. 14) is lowered from vessel 11 into engagement with the connector cap elements of the wellhead assemblies. The four-well control pod includes an extendible and retractable control pod support 152, which is adapted to be placed over the center guidepost of template means 24, and contains supervisory controls and central hydraulic power supply for the control packages. Extending outwardly from the central body portion of control pod 151 are a plurality of

arms

153, 154, 155 and 156. Disposed on the outer ends of the arms are

cupshaped contact members

157, 158, 159 and 160 which are adapted to be placed over the connector caps of the production wellhead assemblies. The cup-shaped contact members have disposed about the peripheries thereof contact receptacles for the stab connectors of the connector caps. Hydraulic or electrical leads (not shown) run from the contact members through the central portion of the four-well control pod and thence to a control conduit 161 which extends to vessel 11 or another suitable control point. In this manner, the operation of the production wellhead assemblies may be monitored and controlled from any desired remote location.

While in FIG. 14 the cup-shaped contact members are illustrated as being rigidly attached to the remainder of the control pod by means of arms, it may be desirable to provide some degree of movement between the cup-shaped contact members and the remainder of the control pod to accommodate for any misalignment between the cup-shaped contact members and the production wellhead assemblies. In FIG. 16, for example, a cup-shaped contact member 162 is illustrated as being axially movable with respect to a mounting ring 163 which is fixedly attached to a retractable and extendible arm 164. Such movement may be effected by means of suitable hydraulic actuators (not shown) or by any other suitable means such as an electric motor arrangement or a simple slide arrangement which will permit the cup-shaped contact members to slide in or out and rotate as they functionally engage the associated connector caps thereby providing proper positioning. In addition, arm 164 may be rotatably mounted within mounting conduit 165 so that the arm may be rotated relative thereto, as desired. Therefore, with respect to central portion 166 of the control pod, the cup-shaped contact member 162 has three degrees of motion, as indicated by the arrows in FIG. 16.

I claim as my invention:

1. A method of drilling and producing multiple underwater wells from a vessel floating on a body of water, said method comprising the steps of:

lowering template means, including multiple aperturedefining means, from the vessel into said body of water; installing said template means by first drilling a foundation pile hole into the earth underlying said body of water and then positioning a portion of said template means within said pile hole, and cementing said template means portion in said pile hole with said multiple aperture-defining means positioned above the earth underlying said body of water;

establishing guideline means between said vessel and said template means before lowering the drill string and bit from said vessel and wherein said guideline means and said drill string and bit cooperate to position said drill string and bit with respect to each of said apertures, said guideline means being repositioned with respect to said template means to facilitate the drilling of said well bores; lowering a drill string and bit from said vessel;

drilling through each of said multiple apertures with said drill string and bit so that a plurality of underwater well bores are drilled; and

lowering production equipment from said vessel into operative association with said plurality of well bores.

2. The method of claim 1 wherein the step of lowering production equipment into operative association with said plurality of well bores comprises separately lowering production equipment modular elements along guideline means with said modular elements being positioned on said template means.

3. The method according to claim 1 wherein said guideline means is repositioned with respect to said template means to facilitate the drilling of said well bores.

4. The method according to claim 1 wherein surface casing is installed for each of said plurality of underwater wells prior to the completion of drilling with respect to said wells, said casing extending from said template means into each of said well bores.

5. The method of claim 4 wherein said surface casing serves to at least partially support said production equipment when said equipment is in operative association with said well bores.

6. An apparatus for facilitating the drilling of wells and production therefrom under a body of water, said apparatus comprising:

template means adapted for installation below said body of water, said template means including base plate means having a plurality of apertures formed therein;

a columnlike support means extending from said baseplate means and adapted to be secured in the earth to support said base plate above said earth, said support means is located at the center of said baseplate and said apertures are located equal distances from said support means; and

guideline attachment means on said template, guidelines extending from said guideline attachment means to a vessel floating on the surface whereby drilling and production equipment may be lowered onto said baseplate.

7. The apparatus of claim 6, and in addition a drilling assembly adapted to be lowered on said guidelines, said drilling assembly having a plurality of arms, one said arm engaging said support means to space said drilling assembly so that wells may be drilled through said apertures.

8. The apparatus of claim 6, and in addition a plurality of well casings, one of said well casings being inserted in each of said apertures and cemented in the earth before the first well is drilled.

9. The apparatus of claim 6, and in addition a production manifold module including a plurality of manifold means for producing wells drilled through each of said apertures, said manifold module also including means for engaging said support means to align the module with the previously drilled wells in said apertures.

10. The apparatus of claim 9 wherein said manifold module includes means to pull flow lines down to said module and connect them to production lines on said module.

11. The apparatus of claim 9, and in addition a plurality of production wellhead assemblies, one of said assemblies being installed on each manifold on said module.

Claims

1. A method of drilling and producing multiple underwater wells from a vessel floating on a body of water, said method comprising the steps of: lowering template means, including multiple aperture-defining means, from the vessel into said body of water; installing said template means by first drilling a foundation pile hole into the earth underlying said body of water and then positioning a portion of said template means within said pile hole, and cementing said template means portion in said pile hole with said multiple aperture-defining means positioned above the earth underlying said body of water; establishing guideline means between said vessel and said template means before lowering the drill string and bit from said vessel and wherein said guideline means and said drill string and bit cooperate to position said drill string and bit with respect to each of said apertures, said guideline means being repositioned with respect to said template means to facilitate the drilling of said well bores; lowering a drill string and bit from said vessel; drilling through each of said multiple apertures with said drill string and bit so that a plurality of underwater well bores are drilled; and lowering production equipment from said vessel into operative association with said plurality of well bores.

6. An apparatus for facilitating the drilling of wells and production therefrom under a body of water, said apparatus comprising: template means adapted for installation below said body of water, said template means including base plate means having a plurality of apertures formed therein; a columnlike support means extending from said base plate means and adapted to be secured in the earth to support said base plate above said earth, said support means is located at the center of said baseplate and said apertures are located equal distances from said support means; and guideline attachment means on said template, guidelines extending from said guideline attachment means to a vessel floating on the surface whereby drilling and production equipment may be lowered onto said baseplate.