Offshore Drilling And Well Completion Method

Abstract

A method is provided for drilling and completing hydrocarbon production wells in substantial depths of water. Such method includes a surface vessel and a submarine drilling vessel. After the surface vessel sets and cements at least one pipe in the formations below the floor of the body of water, the submersible drilling vessel is coupled in a watertight manner to the pipe and drilling of a well is performed from the interior of the submersible drilling vessel which houses well drilling equipment and logging and completion equipment. Such interior of the submersible drilling vessel is substantially at atmospheric pressure and is in fluid communication with the surface vessel. If the drilled well is completed as a producing well, the submersible drilling vessel installs suitable valves on a plate means which is left on the floor of the body of water when the submersible drilling vessel is moved to another location.

Parent Case Text

The present application is a division of application Ser. No. 696,047, filed Jan. 5, 1968 and now U.S. Pat. No. 3,516,489.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to apparatus and methods utilized in drilling and completing wells on the floor of a body of water, particularly when such body of water has considerable depth.

2. Description of the Prior Art

During recent years considerable activity in the search for oil and gas in offshore areas has resulted in much sophistication of apparatus and methods which may be utilized in drilling and completing wells on the floor of a body of water. At the present time there are several types of drilling rigs which are utilized in drilling wells in a body of water but such drilling rigs generally require the use of divers who are limited in the water depths in which they can work and also the duration of time is limited for such divers to work at considerable depths. Known devices and methods also leave much to be desired in the way of completing a well drilled on the floor of a body of water.

Present apparatus and methods are very expensive, lack mobility, and are subject to wave, wind and other weather conditions which result in the rigs being inoperative for considerable lengths of time while drilling a well from the surface of a body of water.

Some of the known devices and methods utilized in offshore drilling operations are set forth in various U.S. patents which disclose surface drilling operations. Multiple well drilling operations are known as are surface drilling operations where pressure or weight on the drill bit is controlled.

One known U.S. Patent discloses an underwater vessel of the submarine type which rests on the floor of a body of water and which is cumbersome and difficult to position and navigate. Such submarine type vessel provides only a "core hole" and not a production well. Completion of a producing well cannot be accomplished with such submarine type vessel because electric logs cannot be run and gun perforating cannot be performed. Also core samples cannot be taken and examined on the floor of a body of water when using a submarine-type vessel. The storage space is also limited so that not much drill pipe can be stored and the depth of the "core hole" is limited to relatively shallow depths.

SUMMARY OF THE INVENTION

The present invention is related to apparatus and methods for drilling and completing a well in a body of water. The apparatus includes a surface vessel and a submersible hull vessel which houses a complete drilling rig and accessories, such as electric logging equipment, and equipment for taking core samples, perforating, and performing other related work necessary for completing a well. Such submersible hull vessel includes positioning means for fixedly positioning such submersible hull vessel on the floor of the body of water. The submersible hull vessel is not subjected to wind and wave action and, therefore, may be utilized in drilling operations continuously from the time that the submersible hull vessel is properly positioned on the floor of a body of water. When the submersible hull vessel is submerged, the interior of such vessel utilizes air at approximately atmospheric pressure. The submersible hull vessel is coupled to anchoring devices which have been positioned by the surface vessel and the submersible hull vessel is lowered into position over stub means by filling the ballast tanks with water. The stub means include a conductor pipe and a surface pipe which has been positioned and cemented on the floor of the body of water at the location where the well is to be drilled. The submersible hull vessel includes hatch means which allow a small submarine to be positioned in the upper portion of said submersible hull vessel to allow small parts, such as drill bits, and personnel to enter and be removed from the submersible hull vessel. The submersible hull vessel includes water jet discharge means for vertical positioning of the submersible hull vessel and also means for controlling the buoyancy of the submersible hull vessel. After the well has been drilled, an electric log is run from either the submersible hull vessel or from the surface vessel prior to setting production pipe from the surface vessel after the submersible hull vessel is moved from the well site. After the production pipe has been run and cemented, the submersible hull vessel is positioned over the conductor pipe, clamps onto the conductor pipe, and completes the well by drilling out any cement that might be lodged in the production pipe. The submersible hull vessel will then gun perforate the production pipe, either run production tubing or leave the drill pipe in the hole as a substitute for the tubing, and install control valves (Christmas tree) in air at approximately atmospheric pressure to complete the well as an oil or gas producer. A bottom plate on the submersible hull vessel is then removed with the control valves being attached to such bottom plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 through 6 show a typical sequence of operations utilizing the apparatus and methods of the present invention;

FIG. 7 is a sectional, elevational view of the submersible hull vessel of the present invention showing such submersible hull vessel positioned on the floor of a body of water;

FIG. 8 is a top view of the submersible hull vessel of the present invention showing guy wires coupled to the submersible hull vessel for vertical positioning of such submersible hull vessel;

FIG. 9 is a sectional, top view showing the winch means positioned on the exterior of the submersible hull vessel for tightening the guy wires anchored to the floor of a body of water;

FIG. 10 is a side elevational view showing the surface vessel, a submarine, and the submersible hull vessel positioned on the floor of a body of water;

FIG. 11 is a sectional top view of the submersible hull vessel showing the guy wires coupled to the submersible hull vessel and further showing the typical radial jet system utilized in stabilizing the submersible hull vessel;

FIG. 12 is a top view through a section of the submersible hull vessel showing drill pipe and the draw works positioned inside such submersible hull vessel;

FIG. 13 is a broken sectional view taken along line 13--13 of FIG. 12 showing a typical installation of drill pipe in the finger board of the submersible hull vessel;

FIG. 14 is a bottom view showing the radial fins and the supports positioned on the bottom of the submersible hull vessel; and

FIG. 15 is a sectional, elevational view of the lower portion of the submersible hull vessel showing such submersible hull vessel in position at a well site on the floor of a body of water.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings in detail, FIG. 1 is an elevational view showing a body of water 10 having a floor 12. Anchor devices 14 and 16 have been positioned on the floor of the body of the water near the well site 20 and anchors 14 and 16 have cables 22 and 24 coupled respectively to anchor 14 and anchor 16. A buoy 26 is coupled to cable 22 and a buoy 28 is coupled to cable 24. Although only two anchors and two lines are shown in FIG. 1, the present invention contemplates the use of three anchors as will be shown and described in detail subsequently.

Also shown in FIG. 1 is a surface drilling vessel 30 equipped with a drilling rig 32. The surface drilling vessel, in practicing the present invention, is utilized to drill, set and cement a conductor pipe 34 which may be about 200 feet in length and from 24 inches to 30 inches in diameter. After the conductor pipe has been set at the well location on the floor of the body of water 10 the surface drilling vessel drills and sets surface pipe 36 which may be from about 1,000 to 2,500 feet in depth. The surface pipe 36 is cemented to the conductor pipe 34. Surface pipe 36 may be from 13 inches to 16 inches in diameter.

Generally, the surface drilling vessel will set the conductor pipe and surface pipe prior to installation of the anchors such as 14 and 16. After the anchors and buoys have been set as shown in FIG. 1, a submersible hull vessel 40 is moved into position at the well site by a tug 42 coupled to the submersible hull vessel through suitable means such as a cable or line 44.

FIG. 2 shows the submersible hull vessel 40 being lowered into position near the well site 20 after coupling lines 22, 24, and 25 to the submersible hull vessel 40. Tug 42 tows the submersible hull vessel 40 to the drill site. Upon arrival at the drill site, and before the submersible hull vessel 40 is submerged, a flexible pipeline or hose 45 containing a supply of air, electric power or other power, drilling mud delivery and return, telephone communication and closed circuit television is attached to the submersible hull vessel 40 from the surface drilling vessel 30 or other suitable vessel which can fulfill the needs of the submersible hull vessel 40. Surface drilling vessel 30 is shown for illustration purposes but it will be appreciated by those skilled in the well-drilling art that a more economical surface vessel might be provided when practicing the invention. The submersible hull vessel 40 is positioned over the well site 20 by winches located on the exterior of the submersible hull vessel 40 and such winches are coupled to the cables 22, 24, and 25 to draw the submersible hull vessel 40 into position. Also, the submersible hull vessel 40 contains ballast tanks, the operation of which will be explained in detail subsequently, and these ballast tanks are filled with water to allow the buoyancy of the submersible hull vessel 40 to be varied so that as the submersible hull vessel 40 is lowered into position, the submersible hull vessel 40 is partially filled with water to cause the submersible hull vessel 40 to sink in the body of water.

FIG. 3 shows the submersible hull vessel 40 positioned over the well site 20 which has stub means protruding from the floor 12. Such stub means includes the conductor pipe and surface pipe which was set previously by the surface drilling vessel. FIG. 3 shows the submersible hull vessel 40 positioned over the well site 20 with the guy wires 22, 24, and 25 utilized for stabilizing the submersible hull vessel. As will be shown in detail subsequently, submersible hull vessel 40 includes hatch means whereby a small submarine may be positioned in the upper portion of the submersible hull vessel 40 to provide supplies and personnel to such submersible hull vessel 40.

FIG. 4 shows the submersible hull vessel 40 removed from the well site 20 after drilling operations have been completed. Surface drilling vessel 30 having a derrick 32 is utilized for running production pipe 46 after the submersible hull vessel 40 has drilled the hole and run an electric log at the well site 40. The submersible hull vessel 40 as shown in FIG. 4 is moved off of the surface of the conductor pipe to allow the production pipe 46 to be run and cemented from the surface vessel.

FIG. 5 shows the submersible hull vessel 40 repositioned over the well site 20. The submersible hull vessel 40 is positioned over the well site 20 and clamps onto the conductor pipe and completes the well by drilling out any cement which might be lodged in the production pipe which was set by the surface drilling vessel 30. When the cement has been drilled out, the casing opposite potentially productive sands is gun perforated in a manner well known in the drilling art. The submersible hull vessel 40 then will install control valves, commonly called a Christmas tree, will leave the drill pipe in the hole as a substitute for tubing, and if the well is productive will complete the well as an oil or gas producer on the ocean floor. The guy lines 22, 24, and 25 are utilized again in repositioning the submersible hull vessel 40 over the well site 20 when the well is completed.

FIG. 6 shows the submersible hull vessel 40 being removed from the well site 20 after the Christmas tree 50 has been installed. As pointed out previously, the buoyancy of the submersible hull vessel 40 may be controlled through ballast tanks positioned in the submersible hull vessel 40. The guy lines 22, 25, and 24 are utilized to stabilize the submersible hull vessel 40 as it is raised to the surface of the body of water 10.

FIG. 7 is an elevational, sectional view of the submersible hull vessel 40 shown positioned at the well site on the floor of a body of water. Generally, the submersible hull vessel 40 is of a size which will accommodate normal drill pipe and which will allow drilling of a well in a known manner through use of a rotary table well known in the drilling art. Although the dimensions of the submersible hull vessel 40 may be subject to variation, the dimensions are such that the equipment set forth hereafter may be accommodated in such submersible hull vessel. The submersible hull vessel during drilling of a well on the floor 12 of a body of water rests on floor 12 through a plurality of fins such as fin 52 and fin 54 shown in FIG. 7. Such fins may have disposed between the bottom portion 56 of the submersible hull vessel 40 and the lower portions of the fins, such as fins 52 and 54, a plurality of jacks or support means which will be explained in detail subsequently to aid in positioning the submersible hull vessel 40 in the event that the floor 12 is not substantially horizontal. Conductor pipe 34 is shown along with surface pipe 36 in FIG. 7. The lower part of submersible hull vessel 40 is equipped with a watertight seal 58 to prevent water from coming into the lower portion of submersible hull vessel 40, and to allow proper circulation of the drilling mud while a well is being drilled on the floor of a body of water. The lower portion of the submersible hull vessel 40 includes a ballast tank 60 and a ballast tank 62 which may be filled with water to control the buoyancy of the submersible hull vessel 40 as explained previously. A staircase 64 leads from the bottom portion 56 of the submersible hull vessel 40 to the platform 66. Additional ballast tanks 68 and 70 are provided near a blowout preventer 72. A control valve 74 is positioned above blowout preventer 72 and additional ballast tanks 76 and 78 are disposed horizontally of control valve 74. A plurality of watertight hatches, such as hatches 80, 82, and 84, are provided for sealing the respective compartments in the lower portion of the submersible hull vessel 40. A jet water pump 86 is provided and a mud sump 88 and mud pump 90 are coupled to line 92 which in turn goes through the cable connection 44 to the surface vessel where air, mud, electric power, telephone, television, and fresh water may be provided as pointed out previously. A conventional rotary table 94 is utilized during the drilling operation along with a conventional draw works 96 which may be operated by electric power supply motors 98. Although an electric power supply is contemplated as part of the best mode for practicing the invention, it will be appreciated that other power supply sources such as internal combustion engines may be utilized and the exhaust from such internal combustion engines is discharged through a snorkel at the surface of the body of water. Drill pipe sections such as those shown in group 100 are positioned inside the submersible hull vessel 40 and are circumferentially positioned around the rotary table 94 as will be explained in detail subsequently.

The draw works 96 has stored thereon a cable 102 which passes over a crown block 104 positioned on support 106 in a manner well known in the drilling art.

The drill pipe is stored in section 100 on a finger board 108. The finger board 100 will be explained in detail subsequently.

The crown block 104 is coupled to the traveling block 110 which has elevators 112 coupled thereto in a manner well known in the drilling art.

Cable 24 is shown coupled to a hoist 114 and the operation of hoist 114 and cable 24 has been explained previously.

A plurality of water jets may be utilized and positioned at points 116 and 118 to provide stability to the submersible hull vessel 40. The upper portion of the submersible hull vessel 40 includes a platform 120 on which is positioned supports 122 and 124 for a small submarine 130. Submarine 130 gains access to the upper portion of the submersible hull vessel 40 through hatch means which include pivotal doors 132 and 134. The pivotal doors 132 and 134 allow the submarine 130 to enter the submersible hull vessel 40.

Watertight hatches 136, 138, 140, 142 and 144 allow sealing off the sections in the upper part of the submersible hull vessel 40.

A detachable nose 146 is coupled to the upper part of the submersible hull vessel 40. The detachable nose 146 may be removed after towing of the submersible hull vessel 40 to the well site.

Chamber 148 is a watertight capsule which may be utilized as a personnel capsule for the transfer of personnel and small parts from the submersible hull vessel 40 to the surface drilling vessel 30.

Area 150 may be utilized for food stores, clothing, or other items and compartment 152 may be utilized as a galley. Area 154 may be utilized as crew quarters with staircase 158, 160 and 162 providing access from platform 120 to the personnel capsule 140.

The interior of the submersible hull vessel 40 will be in air at atmospheric pressure thereby allowing the personnel operating inside of the submersible hull vessel 40 to remain in such submersible hull vessel for extended periods of time although the vessel may be operating at substantial depths so that the entire submersible hull vessel may be completely submerged. Thus, artificial atmosphere in the submersible hull vessel 40 is avoided. Of course, it will be appreciated that if the submersible hull vessel 40 is of substantial length because of design and engineering effectiveness, part of the upper portion of the submersible hull vessel 40 will protrude from the water when the submersible hull vessel is in operation on the floor of a body of water.

The arrangement shown in FIG. 7 for various equipment and compartments of a submersible hull vessel 40 has been chosen because such arrangement is thought to be optimum in the operation of the submersible hull vessel 40 but it will be appreciated that variations and changes may be made to accommodate various engineering design requirements. It will be apparent to those skilled in the drilling art that the crown block and traveling block and draw works are utilized for drilling a well through the use of drill pipe stored as shown in section 100. The method of drilling the well after the submersible hull vessel 40 rests on the floor of the body of water is fairly conventional except that the completion of the well on the floor of the body of water is thought to be completely novel.

FIG. 8 is a top view of the submersible hull vessel 40 showing the cable or connection 45 coming from the submersible hull vessel 40 to the surface vessel floating on the body of water. Cable 24 is shown coupled to winch 114 and cable 22 is shown coupled to winch 164. Cable 25 is shown coupled to a winch 166.

It will be appreciated that when the submersible hull vessel 40 is floated into position near the well site that the winches are coupled to the anchors which have been positioned near the well site so that the winches can move the submersible hull vessel 40 into position over the conductor pipe and surface pipe which has been set by the surface drilling vessel. The winches, such as winch 114, winch 164, and winch 166, are positioned on the exterior of submersible hull vessel 40 but are operable from inside of the submersible hull vessel 40. Although only a single conductor 45 has been shown it will be appreciated that a plurality of cables or tubes may be utilized to provide air exhaust from the submersible hull vessel 40 to the surface vessel and for providing power, air, drilling mud and fresh water from the surface vessel to the submersible hull vessel 40. It will be appreciated, of course, that the foul air in the Submersible hull vessel 40 also could be exhausted from the hull into the body of water by the use of air compressors.

FIG. 9 is a partial-sectional top view of the submersible hull vessel 40 showing winch 114 coupled to cable 24. The operation of winch 114 is well known with a power source feeding power through cable 170 from inside the submersible hull vessel 40 to a motor 172 which in turn drives spool 174 having a cable thereon. The winch 114 is positioned on the exterior of the submersible hull vessel 40 in a manner explained previously.

FIG. 10 is a side elevational view showing submersible hull vessel 40 positioned at the well site 20 with submarine 130 moving into position near the submersible hull vessel 40. Surface vessel 30 is coupled to the submersible hull vessel 40 through line 45. As explained previously, the submersible hull vessel 40 is anchored through guy leads 22, 25, and 24. The submarine 130 may be of a relatively small type which carries only several people and has a limited amount of storage space. The submarine 130 is utilized, as explained previously, to transport personnel and equipment to and from the submersible hull vessel 40.

FIG. 11 is a cross-sectional, top view showing the radial jet system utilized in providing stability to the submersible hull vessel 40. Cable 25 is shown coupled to winch 166, cable 24 is shown coupled to winch 114 and cable 22 is shown coupled to winch 164.

A plurality of water jets such as water jet 116 and water jet 118 are positioned circumferentially in the upper portion of the submersible hull vessel 40. As shown in FIG. 11, the jets may be eight in number although fewer jets or more jets may be provided. The jets shown in FIG. 11, in addition to the jets 116 and 118, are 180, 182, 184, 186, 188 and 190. An intake 192 allows water from the body of water in which the submersible hull vessel 40 is working to enter through a check valve 194 to a pump 196. Pump 196 provides pressure to the water and allows selective discharge through the valves such as valves 198, 200, 202, 204, 206, 208 and 210 as well as valve 121.

It will be appreciated that suitable equipment may be provided inside the submersible hull vessel 40 to allow selective discharge from the one or more of the radial jets to aid in stabilizing the submersible hull vessel 40 during the drilling of the well and during completion of the well. It will be appreciated that the check valve and pump arrangement shown with respect to jet 180 may be duplicated for each of the radial jets. Since the submersible hull vessel 40 is positioned in water, the radial jet system utilizes the abundance of the water to provide stability to the submersible hull vessel 40 in the manner just described.

FIG. 12 is an upper sectional view of the submersible hull vessel 40 showing the finger board 108. The draw works 96 driven by motor 90 also is shown in FIG. 12 with cable 102 from the draw works coupled to the crown block 104.

The finger board 108 includes a plurality of slotted members such as 214, 216, 218, 222, 224, 226, 228, 230, 232, 234, 236, 238 and 240.

As shown in FIG. 12 with respect to slot 238, a plurality of drill pipe sections such as 242, 244, 246 and 248 are positioned in slot 238. As additional sections are required to be added to the drill string during drilling of the well, the drill pipe sections are removed from the slots in the finger board 108 and added to the drill string in a manner well known in the drilling art.

FIG. 13 is a partial-sectional, elevational view taken along line 13--13 of FIG. 12 showing drill pipe sections 242, 244, 246 and 248. Upper finger board 108 is shown having suitable fastening means 250 for holding the plurality of drill pipe sections in position, particularly when the submersible hull vessel 40 is being moved from one well location to another well location while the submersible hull vessel 40 is in a horizontal position on the surface of the body of water. A similar lower finger board 252 is positioned in the lower portion of the submersible hull vessel 40 to accommodate the lower portions of the drill pipe, such as sections 242, 244, 246 and 248. The lower finger board 252 also has suitable fastening means 254 for holding the drill pipe sections in position within the slots in the finger board.

The fastening means 250 and 254 include members 256 positioned between a clamp 260 and a section of drill pipe, such as drill pipe 248, and a nut 262 which may be tightened to hold clamp 260 in position. The arrangement of the fastening means 254 may be similar to the arrangement of fastening means 250.

FIG. 14 is a bottom view showing the radial fins and the jacks positioned on the bottom of the submersible hull vessel 40. A plurality of radial fins, such as fins 52 and 54, may be positioned on the bottom of the submersible hull vessel 40. Additional radial fins, such as fins 264, 266, 268, 270, 272 and 274, may be positioned on the bottom of the submersible hull vessel 40. Although eight such radial fins are shown, it will be appreciated that fewer radial fins may be provided or a greater number of radial fins may be provided depending upon drilling conditions and engineering design which will give optimum performance when the submersible hull vessel 40 is utilized for drilling a well and completing a well.

Hydraulic rams or jacks 280, 282, 284 and 286 also are provided on the bottom of the submersible hull vessel 40. The hydraulic rams or jacks 280, 282, 284 and 286 are disposed on the bottom of the submersible hull vessel 40 so that the submersible hull vessel 40 may be positioned on the floor of the body of water so that a straight hole may be drilled during the drilling operation. It will be appreciated that three hydraulic rams or jacks may be used to give tripod stabilization.

A circular rigid flange or plate member 290 is coupled to the bottom of the submersible hull vessel 40 through suitable fastening means such as bolts similar to bolt 292. The circular flange member 290 has an opening 294 through which the drill pipe passes during drilling operations when the submersible hull vessel 40 is positioned on the floor of a body of water. When the well is completed, the circular flange member 290 remains on the floor of the body of water and the control valves are positioned on the circular flange member 290.

FIG. 15 is a partial-sectional, elevational view of the submersible hull vessel 40 showing such submersible hull vessel 40 positioning the control valves or Christmas tree 50 on the well during the completion operations explained previously in conjunction with FIGS. 1, 2, 3 and 4. Radial fins 52 and 54 are shown positioned on the floor 12 of a body of water.

One of the hydraulic rams or hydraulic jacks 284 also is shown positioned on the bottom of the submersible hull vessel 40 with ram 298 coupled to plate 300 which rests on the floor 12 of the body of water and provides leveling of the submersible hull vessel 40. A watertight seal 58 is positioned between the conductor pipe 34 and the circular flange member 290 of the submersible hull vessel 40. Surface pipe 36 has the drill pipe and production tubing positioned therein for completing the well as explained previously. The Christmas tree 50 includes a plurality of valves which are well known in the art and upon completion of the installation of the Christmas tree 50, the circular flange member 290 is removed so that the Christmas tree remains on the floor of the body of water as the submersible hull vessel 40 is floated to the surface of the body of water. It will be appreciated that installation of the Christmas tree or control valves will be performed in air at approximately atmospheric pressure.

It will be appreciated that the circular flange plate member 290 is of sufficient diameter to prevent damage to the Christmas tree 50 as the submersible hull vessel 40 is floated from the floor of the body of water to the surface of such body of water.

It will be apparent to those skilled in the art of drilling wells and completing wells that various refinements and improvements may be made in the procedures which are related to completing a well such as logging, coring, and perforating, and the pressures of the formations being tested may cause refinements and variations in accepted well drilling procedures and well completion procedures. However, it will be appreciated that the present invention encompasses such variations and modifications since the present invention provides a submersible hull vessel which may be completely submerged in a body of water during drilling of a well and during completion of such well.

Although a preferred embodiment of the invention has been shown and described as required by the United States Patent Laws, it will be appreciated that many modifications and variations of the invention may be made without departing from the spirit of the invention as defined by the following claims. Although such claims may be presented in indented format to facilitate reading and understanding thereof, such indented format is not to be construed as a structural or functional limitation of the elements or steps recited in such claims.

Claims

I claim:

1. A method of drilling a well under a body of water, said method comprising the steps of

drilling a hole, setting and cementing a conductor pipe in the floor of said body of water,

drilling a hole deeper than the depth of said conductor pipe, setting and cementing a surface pipe to said conductor pipe in the floor of said body of water,

setting a plurality of anchors in the floor of said body of water near the conductor and surface pipes,

floating into position near said conductor and surface pipes an elongated submersible housing having a drilling rig positioned therein,

coupling said submersible housing to said anchor, and

submerging said submersible housing and coupling the same to said conductor and surface pipes while drilling the well.

2. A method of drilling and completing a well under a body of water, said method comprising the steps of

drilling a hole, setting and cementing a conductor pipe in the floor of said body of water,

drilling a hole deeper than the depth of said conductor pipe, setting and cementing a surface pipe to said conductor pipe in the floor of said body of water,

setting a plurality of anchors in the floor of said body of water near the conductor and surface pipes,

floating into position near said conductor and surface pipes an elongated submersible housing having a drilling rig positioned therein.

coupling said submersible housing to said anchors,

submerging said submersible housing and coupling the same to said conductor and surface pipes while drilling the well,

moving said submersible housing from the well during positioning of production casing, and

repositioning said submersible housing on the well during completion of the well.

3. A method of drilling and completing a well under a body of water, said method comprising the steps of

drilling a hole, setting and cementing a conductor pipe in the floor of said body of water,

drilling a hole deeper than the depth of said conductor pipe, setting and cementing a surface pipe to said conductor pipe in the floor of said body of water,

setting a plurality of anchors in the floor of said body of water near the conductor and surface pipes,

floating into position near said conductor and surface pipes an elongated submersible housing having a drilling rig positioned therein,

coupling said submersible housing to said anchors,

submerging said submersible housing and coupling same to said conductor and surface pipes while drilling the well,

moving said submersible housing from the well during completion of the well,

positioning said submersible housing over said well for installing production valves, and

moving said submersible housing from the completion well to another location.

4. A method of drilling a well under a body of water, said method comprising the steps of

drilling a hole, setting and cementing a conductor pipe in the floor of said body of water,

drilling a hole deeper than the depth of said conductor pipe, setting and cementing a surface pipe to said conductor pipe in the floor of said body of water,

setting a plurality of anchors in the floor of said body of water near the conductor and surface pipes,

floating into position near said conductor and surface pipes an elongated submersible housing having a drilling rig positioned therein,

coupling said submersible housing to said anchor, and

submerging said submersible housing and coupling the same to said conductor and surface pipes in a watertight manner while drilling the well.

5. A method of drilling and completing a well under a body of water, said method comprising the steps of

drilling a hole, setting and cementing a conductor pipe in the floor of said body of water,

drilling a hole deeper than the depth of said conductor pipe, setting and cementing a surface pipe to said conductor pipe in the floor of said body of water,

setting a plurality of anchors in the floor of said body of water near the conductor and surface pipes,

floating into position near said conductor and surface pipes an elongated submersible housing having a drilling rig positioned therein,

coupling said submersible housing to said anchors,

submerging said submersible housing and coupling the same to said conductor and surface pipes in a watertight manner while drilling the well,

moving said submersible housing from the well during positioning of production casing, and

repositioning said submersible housing on the well in a watertight manner during completion of the well.

6. A method of drilling and completing a well under a body of water, said method comprising the steps of

drilling a hole, setting and cementing a conductor pipe in the floor of said body of water,

drilling a hole deeper than the depth of said conductor pipe, setting and cementing a surface pipe to said conductor pipe in the floor of said body of water,

setting a plurality of anchors in the floor of said body of water near the conductor and surface pipes,

floating into position near said conductor and surface pipes an elongated submersible housing having a drilling rig positioned therein,

coupling said submersible housing to said anchors,

submerging said submersible housing and coupling same to said conductor and surface pipes in a watertight manner while drilling the well,

moving said submersible housing from the well during completion of the well,

positioning said submersible housing over said well in a watertight manner for installing production valves, and

moving said submersible housing from the completion well to another location.