US3202218A

US3202218A - Submergible apparatus for underwater operations

Info

Publication number: US3202218A
Application number: US203207A
Authority: US
Inventors: John D Watts; Slack John
Original assignee: Gray Tool Co
Current assignee: Vetco Gray LLC
Priority date: 1962-06-18
Filing date: 1962-06-18
Publication date: 1965-08-24
Anticipated expiration: 1982-08-24

Description

Aug 24, 1965 J. D. WATTS ETAL 3,202,213

SUBMERGIBLE APPARATUS FOR UNDERWATER CERATIONS Filed June 18, 1962 5 sheets-sheet 1 ATTORNEY Aug 24, 1955 J. D. WATTS ETAL 3,202,213

SUBMERGIBLE APPARATUS FOR UNDERWATER OPERATIONS Filed June 18, 1962 5 Sheets-Sheet 2 Aug. 24, 1965 J. n. WAT-rs ETAL SUBMERGIBLE APPARATUS FOR UNDERWATER OPERATIONS Filed June 18, 1962 5 Sheets-Sheet 5 Aug. 24, 1965 J. D. wATTs ETAL 3,202,218

SUBMERGIBLE APPARATUS FOR UNDERWATER OPERATIONS Filed June 18, 1962 5 Sheets-Sheet 4 ATTORNEYS Aug. 24, 1965 J. D. WATTS ETAL 3,202,218

SUBMERGIBLE APPARATUS FOR UNDERWATER OPERATIONS Filed June 18, 1962 5 Sheets-Sheet 5 wm, ya@

ATTORNEYS United States Patent() 3,202,2l8 SUBMERGEILE AFPARATUS FR UNBER- l/VATER OPERATIINS John D. Watts and .lohn Slack, Houston, Tex., assigner-s to Gray Tool Company, Houston, Tex., a corporation of Texas Filed .lune 13, 1962, Ser. No. 293,2@7 22 Claims. (Cl. 16e- 46) This invention relates to offshore oil well drilling operations and particularly to apparatus, procedures and techniques for use in such operations. More specifically it relates to the installing, inspecting and repairing of well head equipment positioned below water level.

It is often considered desirable from the standpoint of cost and from the standpoint of minimizing navigation hazards to position a well head and associated llow control equipment below water level with a minimum of support structure. Several basically different concepts have been applied to effecting well-completion operations below water. One of these concepts fully disclosed in the applicants copending applications Serial Nos. 785,984 filed January 9, 1959 and 138,523 filed September 15, 1961, involves the setting of a large diameter drive pipe into a subsurface bottom with its upper end well below the water surface, releasably securing a relatively large chamber to the upper end of the drive pipe and drilling a well from the surface through the drive pipe, the chamber and an access pipe extending from the chamber to the surface. Well completion operations are then conducted manually by personnel in the charnber, and the chamber is later removed from the top of the drive pipe after the personnel have returned to the surface. The resulting well head is thereby located below the surface and is supported only from below so as to present no navigation hazard. The apparatus and procedures disclose-d in those applications are particularly suited to wells drilled through deep water because the drive pipe serves the purpose of the complicated and costly support structures which are often used to support under water well heads.

The present invention is primarily concerned with effecting well drilling and completion operations in shallow water where the well head is to be positioned, for example, feet below the water level as compared to depths of up to 100 feet in the case of deep water. In some shallow water locations, there are government prohibitions against the construction of any permanent structure in the water which would constitute a navigation hazard. More in particular, then, the invention is coucerned with the formation of thewell head below the mud line so that the well head does not constitute a navigation hazard even in very shallow water. Briefly, the

procedure includes securing a chamber or water cellar to the upper end of a drive pipe, driving the pipe and cellar into the bottom to a position below the mud line and conducting drilling operations from the surface through the cellar and the drive pipe. Well completion operations may then be carried out manually by personnel in the chamber. After the well head has been cornpleted and the men have returned to the surface through the water cellar, the cellar, or at least the major part of it, is released from the drive pipe and is removed for use at other sites. The well head with such protective structure as is necessary remains below the mud line.

Another feature of the present invention is the provision of a well head structure the inner central bore of which is easily accessible from the surface by means of a releasable conduit which can be attached axially to the top of the well head.

Accordingly, it is a primary object of the present invention to provide a novel method of and apparatus for drilling a well from the surface of the water and completing a well head below the surface of the water, which method and apparatus permit a wide variety of Wellforming operations to be carried out with relative ease and economy using a wide variety of well-forming instrumentalities. i

It is a further object to provide a novel submersible housing and a base releasably secured to each other, the assembly of the housing and base being designed to be secured to a drive pipe.

It is a further object to provide a method of forming a well head below the mud line of a submerged bottom which includes securing a chamber to the top of a drive pipe, driving the chamber and pipe into the submerged bottom, forming a well head on top of said pipe from within said chamber and removing the chamber so as to leave the well head below the mud line.

It is a still further object to provide a submerged well head having means for releasably sealing a casing to the top thereof and removable closure means in the top thereof whereby access to the interior of the well head may be had through the casing from above the water surface.

The invention will be more fully understood from a reading of the following description when taken in conjunction with the drawings in which:

FIGURE l is a vertical sectional view of a water cellar illustrating the principles of the present invention;

FIGURE 2 is a sectional view on the line 2 2 of FIG- URE 1;

. FIGURE 3 is a fragmentary view on an enlarged scale of part of FIGURE l;

FIGURES 4 through 13 are schematic elevational views illustrating the use of the water cellar of FIGURE 1 in well forming operations;

FIGURE 14 is an elevational view, partly in section, of a completed well head constructed with the use of the water cellar of FIGURES 1-3 and having means for permitting access to the bore of the well head through a removable access stack; and

FIGURE 15 is an elevational View of a completed well 4head somewhat similar to that of FIGURE 13 and having pressure lines for injecting cleaning chemicals into the flow line and for operating the master valve.

Referring to FIGURE 1, a water cellar lill illustrative of the principles `of the invention includes an upper housing 12 and a base 14 releasably secured together in water tight relationship to form a chamber 15 of suflicient size to permit men to enter and work therein.

The housing 12 may conveniently be formed of one or more lengths of pipe 16 having a diameter of, for example, 6 feet. As seen in FIGURE 3, the lower end of the `housing is constructed with a relatively thickwalled section secured to the` pipe 1.6 as by weld 19. A11 annular flange 20 extends inwardly from section 13, and below the flange the inner surface of the section 1S is tapered inwardly and upwardly as at 22. A resilient sealing ring 24 of conventional construction resides in an annular groove in the tapered surface 22 for engagement with the base 14. A guide ring 26 is provided interiorly of pipe i6 above the section 18 and is secured in place as by welds 27. The guide ring 26 has upper and lower surfaces 28 and 29, respectively, which are tapered inwardly.

Adjacent the exterior surface of section 18 of the housing l2 is provided an annular pipe 3i) having downwardly facing jet openings 32 therein. A vertical water-supply pipe 34 connects at its lower end with the annular pipe and extends upwardly along pipe 16 for connection to a source of water pressure (not shown).

Pipes

30 and 34 y44 of, for example 16 inch diameter.

'of a Hat circular plate 38 having an edge 40 which is `tapered upwardly and inwardly to mate with tapered edge 22 at the lower end of the housing 12. The plate 38 is provided with a central hole into which is secured as by weld 42 one end of an interiorly threaded casing nipple As seen in FIG- URE l the top of the nipple 44 may extend slightly above the upper surface of the plate 38. The lower end of the nipple 44 may be braced to the periphery of the plate 38 in any convenient manner as by plates 46 secured in place by welds 4S.

The base 14 should also include one or more connections for delivering production from the completed well to one or more tlow lines leading to appropriate storage facilities. For purposes ofvillustration a single connection is shown in the drawing but it should be understood that as many connections as desired may be provided. As shown, a short length of flow conduit 50 extends through the plate 33 and is provided at each end with an appropriate connector 52 for placing the conduit 5t) in communication with appropriate apparatus. Leakage between the conduit 50 and the plate 33 may be prevented byrany suitable means such as weld 53. The connectors 52 advantageously may be of any of the types disclosed in Watts et al. Patents Nos. 2,766,999, 2,766,998 or 2,766,829. As seen in FIGURE 2, a suitable connector includes a pair of opposed semicircular clamping rings '54 clamped together by lateral bolts 5S. A sealing ring (not shown) between the rings 54 and the conduit makes a water-tight seal.

Any suitable means may be provided for releasably 'securing the housing 12 to the base 14. As shown, this means includes a plurality of generally L-shaped lugs 56 adapted to engage the upper surface of flange 20 on the '.housing. As seen in FIGURES 2 and 3 these lugs are circumferentially spaced along the flange 20 and are held in tight engagement therewith by bolts 58 which pass through the lugs into the upper surface of the plate 38.

As indicated above, the water cellar of the present invention is intended primarily for use in shallow water and in particular where a well head is desired to be completed below the mud line. Where, for example, the water is about feet deep, a water cellar about 23 feet in height will be suitable for extending from above the water surface'to below the mud line a distance such that the completed well head will not extend above the mud rline. Normally, the iirst step in putting the water cellar 10 into use will be to drive a conductor casing or drive pipe 6l) of relatively large diameter, for example, 16", vertically into the subsurface bottom. In setting the drive pipe, a first section of casing is lowered to the bottom by means of a suitable hanger and cable 62 as illustrated in FIG- URE 4 and then additional casings are added to the top casing as the string is driven into the bottom in a manner known in the art. These and the subsequent operations are conducted from any suitable platform such as a floating drilling rig (not shown) which will include the necessary derrick and other equipment.

When the drive pipe 60 has approached the desired depth, its upper end while still above the water surface ,61 is tted with the assembled water cellar 1i) of FIG- URES 1-3. To accomplish this, the cellar 10 may conveniently be fitted with a length of casing 64 screwed into the upper end of nipple 44 and extending upwardlyV into the housing 12. The top of casing 64 is then gripped with hanger 62 and the entire cellar assembly lowered into engagement with the top of drive pipe 6l). The

Vcellar may then be rotated so as to screw the lower end of nipple 44 onto the top of the drive pipe 61D. Normally at this time an appropriate flow line 66 to storage facilities 4 (not shown) will be connected to conduit 5l) by means of the exterior connector 52.

As illustrated in FIGURE 5 the assembly is then lowered through the water and mud until the base is below the mud line 67 a distance, for example 8 feet, which will permit a completed well head to lie completely below Vthe mud line. To aid in reaching the proper depth, water may be pumped through pipe 36 to the jet ring Sli. To overcome the buoyancy of the cellar at this stage water may be pumped into' the open top of the cellar so as to fill the same. The housing 12 will have been constructed of such height that its upper end will extend above the surface of the water when the assembly has been seated to the desired depth. The drive pipe 6) is then cemented in place by usual cementing operations.

After the drive pipe has been cemented in the bottom, conventional drilling operations may be carried out in a known manner from above the water surface 61. FIGURE 6 illustrates a drill string 68 being lowered for conducting drilling operations through casing 64 and the drive pipe 60. During these operations, casing 64 may conveniently serve as a mud riser and will have any desired control equipment such as blowout prevent- Vers (not shown) attached to the top thereof.

When a string of casing is to be run into the drilled hole, casing 64 is unscrewed from the nipple 44 ofrbase 14 and withdrawn, as illustrated in FIGURE 7. A string of casing, such as 10% inch casing illustrated at 70 in FIGURE 8 is then lowered through the cellar 11i and drive pipe 6'0 while adding additional lengths of casing as necessary. As the last length of casing is added, a foundation landing collar 72 may be made up at the last joint as illustrated in FIGURE 8. The landing collar 72 has a body portion 74 of a diameter to lit inside nipple 44 and an outwardly extending annular flange 76 adapted to rest on top of the upper end of nipple 44. ri`he bore of the collar 72 is interiorly threaded to receive the ends of the last two lengths of casing.

After the collar 72 has been made up, the string of casing 70 is lowered until the flange 76 is about 1 foot above the top of nipple 44. The string, still under tension and supported only by the hanger and cable 62 is then cemented by conventional procedures. Then the hanger and cable 62 are slacked off so that the collar Vcornes to rest on top of nipple 44 as illustrated in FIGURE 9. The top length 71 of 10% suitable means (not shown) so that workmen may enter .the cellar to aid in effecting subsequent well completion operations. These operations may include the conventional installation of a tubing head, tubing and other equipment or they may include novel installations involving new pieces of equipment or new procedures. As illustrated in FIGURE l() a tubing head 78 of the dual type disclosed in Patent No. 3,001,803 with an extension riser Si) and ram-type blowout preventers 82 and other control equipment 84 attached may first be screwed into the top of the collar 76. After this equipment has been installed and tested, drilling may proceed followed by the running of, for example, two strings of 2% inch tubing 86 to be landed in the tubing head 78. The tubing may be set in any conventional manner either with or without packers or it may be cemented.

After the tubing has been set, the extension riser t) with the blowout preventers 82 and other control equipment 84 is unbolted from the top of the tubing head '78 and is removed as illustrated in lFIGURE 11. The clements of a conventional Christmas tree 90 may then be lowered through the housing 12 and mounted on the top of the tubing head 78 by workmen in chamber 15 in a manner known in the art. Flow lines, such as the one .illustrated at 92, are then connected from the outlets of the Christmas tree 90 to their respective flow conduits 50 and the well may then be tested by opening and closing the Christmas tree valves by remote control in order t ascertain the characteristics of the tluid produced.

A `Christmas tree protector 94 of any suitable design may then be mounted over the Christmas tree 9@ after workmen have left the cellar 1t). As shown, the protector 94 is a generally cylindrical shell, open at the bottom and closed at the top, which is of a diameter to be easily lowered through the housing 12. The upper portion of the protector 94 may be tapered inwardly and upwardly as at 96. Any convenient means may be utilized for securing the protector 94 in place, such as a large bolt 98 extending through the top of the protector into a threaded hole which has been provided in the top of the Christmas tree 9d for the purpose. It is not necessary that the protector 94 be installed so as to prevent leakage of water and mud to the interior thereof. A plurality of circumferentially spaced, vertical ribs 100 may be provided on the outside of the protector 94 if desired. These ribs 161B slidably engage the inner periphery of ring 26 on the interior surface of the housing 12 during descent of the protector 94 and aid in accurately positioning the same. In addition, in centering the protector 94 with respect to the housing 12 the ribs 1G41 assure that all the lugs 56 and bolts 58 (FIGURES 1-3) are exposed for manipulation from the surface by an extension wrench (not shown).

After the protector 94 has been installed, the bolts 5S may be removed thus releasing the housing 12 from the base 14. The housing 12 may then be hoisted to the surface by any convenient means and used again at other sites. The completed well head being secured to the drive pipe 6d by means of the base 12 remains submerged below the mud line 67, and its location may be marked with a suitably buoy if desired. The housing 12 may be later replaced on the base 14 if it becomes necessary to repair or inspect the well head. In this event, the housing il is lowered through the water and mud while the jets 32 are operated to clear a path through the ud. As the housing 12 telescopes over the protector 94 guide ring 26 slidably engages rst the tapered surface 93 of the protector and then the edges of ribs 1611 so as to guide the housing easily into place. Lugs 56 and bolts 58 may then be secured to hold the housing 12 to the base 14. The water and mud within the housing 12 may then be pumped out in any convenient manner so that the protector 94 is made accessible for removal. After the protector has been removed and after any additional mud has been pumped out, men and equipment may be lowered into the chamber 15 for inspection or repair of the well head.

FIGURE 14 illustrates a somewhat different well head and water cellar arrangement in which parts similar to or the same as those already described are numbered with primed reference numerals. The housing 12', lugs S6', bolts S and pipes Eil and 34 are the same as disclosed in prior iigures, but the base 14 differs somewhat in that nipple 44' extends only about halfway through plate 36', the two being welded together at 42 at the lower surface of the plate. Above the top of the nipple 44 the opening in the plate 36 is tapered downwardly and inwardly as illustrated at 162; otherwise the plate 38 is the same as plate 3d. Plates 46 are welded to the nipple 44 and to the plate 33 at 415 in the same manner as already described. The bottom of nipple 44' is shown welded to the top of drive pipe 66 at 104.

In the arrangement illustrated in FIGURE 14, the well includes two strings of casing in addition to the drive pipe and the tubing string. The irst string of casing 70', which may be identical with the inch string 7), is hung from collar 72 which differs from collar '72 in that the periphery of ilange 76 is tapered downwardly and inwardly and mates with the taper 162 of the opening in plate 33. The body 74' of the collar 72' rests in the top of nipple 44' in the same manner as collar body 74 rests in nipple 44.

After the string of casing '70 has been hung, for example in the same manner as casing 79, a casing head 106 is screwed into or otherwise suitably secured to the upper end of collar 72. If desired, the casing head 106 may be constructed integrally with the collar 72' and installed simultaneously with the string 70. A second string of casing 10S', for example 7 inch casing, may then be lowered through casing string 7d and suspended by means of a suitable hanger (not shown) at a ared hanger seat 116 in the casing head 166 in a manner known in the art. The casing head 196 may be of any conventional construction such as that described in detail in Smith et al. Patent No. 2,148,327. The casing head may include, for example, conventional side outlets which may be closed by a bull plug 112 or provided with a valve 114.

Above the casing head 196 and connected thereto is a tubing head 118. The connection between the heads may be made by a sealing ring and clamp 116 of any of the types disclosed in the before-mentioned Patents 2,766,999, 2,766,998 or 2,766,829 or by suitable flanges and bolts or by a remotely controlled connector such as that disclosed in Watts et al. copending application Serial No. 128,174, led July 31, 1961. As shown, the tubing head 11S is of the dual type disclosed in Watts et al. Patent 3,091,803 and is provided with a flared hanger seat 12h adapted to receive a tubing hanger for two strings of tubing S6 as also disclosed in the patent. The tubing head 11S may also be provided with side outlets which may be closed with a suitable plug 122 or provided with a valve 124. As shown, the plug and valve assemblies are connected to the side outlets by means of the before-mentioned ring clamps.

After tubing 86 has been landed in the tubing head 11d, a tubing head cap 126 may be connected to the top of the tubing head 118 in a convenient manner as by means of another ring clamp 116. The tubing head cap 126 may be of the type disclosed in Watts et al. Patent 3,091,803 and may have dual inner channels 123 each of which communicates with the bore of one of the strings of tubing 86'.

A Christmas tree 130 may then be mounted on top of the tubing head cap 126 either in sections or as an assembled unit. As shown, the Christmas tree 1311 includes two master valves 132 bolted one above the other to the tubing head cap 126, a dual T manifold 134 bolted to the top of the upper master valve 132 and provided with two side outlets each having a choke assembly 136 attached thereto with a ring clamp. Each choke assembly 136 is connected to a ow line 92 which in turn is connected to a ilow conduit 50', only one of which appears in FIG- URE 14, passing to the outside of the base 14. Each ow conduit 56 may be connected to a valve 133 by means of a ring clamp 14?. In practice, the valve 138 may be located above or below the mud line and will have its outlet either closed oli by a suitable closure or connected to a suitable line leading to storage facilities, depending on whether or not the well is being operated.

As seen in FIGURE 14, the channels 128 which cornmunicate with the bores of tubing S6 extend upwardly through all the Christmas tree elements and are closed at their upper ends by plugs 142 screwed into the channels in the T manifold 134. According to the invention, the top of the Christmas tree 139 is provided with means for releasably securing a vertical casing thereto so that access may easily be had to the interior of the Christmas tree from the surface of the water without using the water cellar 11i. This means may include any suitable fitting, attached to the Christmas tree in water tight relationship which will permit the lower end of a casing to be releasably placed over the plugs 142 in water tight relationship.

As shown, the fitting consists of a centrally apertured circular plate 144 secured, as by welding, around the manifold 134 near its top. A collar 146, such as a short length of casing interiorly threaded at its upper end, may then be secured to the plate 144 as by welding. The top of the collar 146 may be closed to Vprotect plugs 142 by any suitable means such as a threaded plug 148'. Conveniently, the top of the plug 148 may be provided with means to aid in gripping the same, for example a pair of eyes 149. It is apparent that the particular design of the collar 146 and plug 148 may be varied from that illustrated. For example, in place of the threaded connection between the two, their opposed ends may be flared to receive a ring clamp such as illustrated at 116. When the collar and plug arrangement is included in a well head, the Christmas tree protector should be so constructed as not to interfere with the arrangement. As shown, the protector '94 has a relatively large central top aperture 150 through which the collar 146 extends.

When using the collar and plug arrangement to gain access to the interior of the Christmas tree 130 and of the tubing 36', the plug 148 will first be removed as by grasping the eyes 149 with a suitable extension tool operated from the surface and by unscrewing the plug. Then a casing 152 may be lowered from the surface and screwed into the open end of collar 152 after which plugs 142 may be removed by a suitable extension tool lowered through the casing 152. The interior of the Christmas tree will thus be made accessible from the surface without using the more cumbersome housing 12. FIGURE illustrates a well head embodying still another concept of the present invention. ln this embodiment, where previously described elements are designated with double-primed numerals, a well head somewhat similar to that illustrated in FIGURE 13 has been installed With the use of the water cellar of the invention. As shown, the top length of a string of casing 70 has been hung from nipple 44I with the aid of a foundtion collar 72 in the manner previously described. A conventional tubing head 156 having its side outlets closed with plugs 112 has been mounted on the top of the collar 72" for supporting tubing 86" and above this a conventional remotely controlled master valve 158 has been mounted. Finally, a conventional T manifold 161B, having a single side outlet and associated choke assembly 136, has been secured to the top of the master valve 158. The top of the T manifold is provided with a closure plug 142 and with a fitting which permits access to the interior of the well head from above the surface of the water. As shown, the fitting includes a plate 144, a collar 146", a plug 148, and eyes 149 as fully .described with respect to FIGURE 14.

According to the invention the control system for the remotely-controlled master valve is combined with a system for injecting liquid cleaning chemicals into the flow stream from the well head in a manner such that a single, pressurized chemical line controls both systems. Broadly, this is accomplished by providing pressure-to-open valve actuators for the master valve and for the valve which permits injection of chemical into the flow stream and by connecting both actuators to a single pressurized chemical line. Preferably, a third pressure responsive valve is provided between the iiow line and the chemical line so that a decrease in ow line pressure reduces chemical line pressure to a value at which the master valve will close.

As shown in FIGURE l5, the base 14 of the water cellar is provided with a supply line 162 for carrying a liquid cleaning chemical such as glycol which is known to be an effective solvent for the paraffin which occasionally tends to coat or lodge in the liow line of an oil well. Above the plate 33 of the base 14 the line 162 is connected by means of a connector 52 and a chemical feed line 164 to` the combined control system for the master ,valve 158 and the chemical injection system.

According to the invention the chemical feed line 164 `communicates with a pressure-to-open actuator 166 for the master valve and with the ilow stream as by means of an inlet line V161i connecting with the T manifold 161).

A pressure regulator 176 is provided between the actuator 156 and the feed line 164 for maintaining a pressure at the actuator 166 sufficient to maintain the master valve 158 open (provided that the pressure in line 164 is higher than the pressure necessary to open the actuator 166). Between the inlet line 168 and the feed line 1&4 is provided a pressure relief valve 172 which opens at a predetermined pressure in line 154 to inject glycol or other suitable cleaning liquid into the T manifold 161D and thus into the iiow line 92" and ow conduit 56". The chemical feed line 164 also communicates with the ow line 92 through a bleed down valve 174 and connecting

lines

176 and 178. The valve 174 is provided with an actuator 1S@ which opens the valve when the pressure in the ow line 92 drops to a predetermined value.

Under normal conditions of oil iiow through the flow line 92, the chemical in feed line 164 is maintained under pressure by suitable equipment located on the shore or at some other remote location. The regulator maintains a pressure, P1, on the master valve actuator 166 sufficient to open the master valve 158 so that as long as the pressure, P2, in line 162 is equal to or exceeds P1, the master valve wili remain open. When it is desired to add cleaning chemical to the oil iiow stream, P2 is increased by mcans of the remote pressurizing equipment to a value at which the relief valve 172 opens thereby injecting the chemical into the T manifold 16) through line 163. To shut off oil production, P2 is decreased to below P1 so that the actuator 16e closes the master valve 158.

Under the conditions just discussed, the bleed down valve 174 remains closed as a result of the action of the flow line pressure, P3, on the actuator 181i. Should a break occur in the flow line 92 or the ow conduit Sti, the resulting reduction in P3 will cause the actuator to open the valve 174. Opening of valve 174 permits flow out of the line 164 thus reducing P2 to less than P1 and causing the master Valve 158 to close. A further advantage of the valve 174 is that the master valve cannot be opened unless pressure is first built up in the iiow line 93". rl`his feature prevents unnecessary cutting of the master valve which would result if the valve were opened or closed against a high pressure differential. Still further this feature prevents the master valve from being opened in the event of a broken flow line 92 or ow conduit 59 and thus prevents loss of oil.

In the event that the bleed down valve 174 has opened and the master valve 158 has thereby been closed, flow in the flow line 92" is re-established by simultaneously Vpressurizing ow line 92 and chemical feed line 164 from the shore. The presence of iiow line pressure will then close the bleed down valve 174 and the presence of chemical line pressure will open the master valve 158, allowing oil to flow.

Thus it will be appreciated that in the flow control system of the present invention, a single pressurized chemical line leading to a well head from the shore or other remote area may be used to actuate the master control valve to inject chemicals into the flow stream, to prevent unnecessary Wear on the master control valve, and to automatically shut down the well in the event of a break in either the flow line or the chemical line. While the control system has been illustrated in combination with a single ow line, it is apparent that the arrangement may be easily modified for controlling a dual well.

As stated above, it is contemplated that the invention, `as descri-bed herein, may be used in association with various well known items of equipment, and combinations of equipment, and in practicing procedures as are known in the art. For instance, the invention con-templates the use of casing hangers, and casing hanging procedures, as disclosed `in Patents 2,082,413, Mueller et al., dated June l, 1937; 2,117,444, Mueller et al., dated May 17, 1938;

9, 2,207,469, Roye, dated July 9, 1940; 2,620,880, Mueller et al. dated December 9, 1952; and 2,624,413, Mueller et al., dated January 6, 1953. Also contemplated is the use of such hangers and associated equipment, and practices, as are disclosed in Patents 2,751,235, dated June 19, 1956 and 2,754,134, dated uly 10, 1956. The invention is likewise applicable for use with tubing hangers and completion practices as disclosed in Patent 2,241,333, Smith, dated May 6, 1941 and Patent 2,150,887, Mueller et al., dated March 14, 1939. The invention is also intended for use in such practices and in association with control devices, such as back pressure valves as disclosed in Patent 2,148,327, Smith, dated February 21, 1939; Patent 2,162,179, Mueller et al., dated June 13, 1939; Patent 2,241,288, Yancey, dated May 6, 1941, and the invention contemplates insertion and removal of tubing closures as disclosed in these patents, as well as in Patent 2,358,677, Yancey, dated September 19, 1944.

While specific embodiments of the various `features of the invention have been described, modifications and changes therein will be apparent to those skilled in the art, and it is not intended that the described details be limiting except as they appear in the appended claims.

Vfhat is claimed is:

l. A method of conducting well-forming operations in water where it isdesired to effect `a Well head below the mud line of a submerged bottom comprising: setting a pipe of relatively large diameter substantially vertically into the submerged bottom with the upper end Vof said pipe above the surface of the water, releasably securing a vertically elongated housing which denes a chamber for workmen at the upper end of said pipe; driving said pipe and said housing downwardly to a position at which the top of said pipe lies below the mud line a distance substantially equal to the height of well-completion equip-` ment to be mounted on the top of said pipe and at which the top of said housing remains above the water surface; conducting drilling operations from above the surface through said housing and through said pipe; establishing -a wel-1 head at the upper end of said pipe within said chamber; installing a protective cover over said well head while said housing holds off mud; and subsequently permitting mud to substantially bury the protective cover by releasing and removing said housing.

2. Submersible apparatus `for use in underwater well- `forming operations comprising: a base member adapted to seal with the lower end of a vertically elongated housing to forma chamber of a size to contain workmen, said base member having a hat upper surface of substantial area and a vertical bore of substantially uniform diameter extend ing `through said upper sur-face; means -at the outer edge of said upper surface defining an exposedannular seating surface; a vertically elongated housing having walls defining an upwardly facing opening in its upper end and a coaxial downwardly facing opening in its lower end, the portion of the wall dening the periphery of the downwardly facing opening being complementary to said seating surface and in engagement therewith there-by forming a chamber with said .base member, said upper surface of said base member defining substantially the entire floor of said chamber and the Wall of said housing adjacent said downwardly facing opening deiining the sides of said chamber; means releasably holding said housing to said seating surface in watertight relationship; and jet mean-s secured to the exterior of said housing, said jet means having discharge openings facing downwardly.

3. Apparatus las in claim 2 wherein said base member includes a short length of vertical pipe and horizontal plate member which defines said ilat upper surface, said plate member having an aperture therethrough and being rigidly connected to the upper end of said short length of pipe with the bore of the pipe and said aperture being in alignment with each other; and a conduit passing downwardly through said plate member at a location between said short length of pipe and said annular seating surface,

the lower `end of said conduit terminating outside said base member below said .annular seating surface.

4. Apparatus as in claim 3 further comprising: a conduit offset from said bore extending through said base member, one end of said conduit communicating with said chamber when said housing is in engagement with said base member and the other end of said conduit extending outside said base member.

Si. Apparatus as in claim 2 wherein said base member includes a relatively at plate member, said upper surface of said base member being deiined by said -relatively flat plate member, the peripheral edge of the latter engaging the periphery of said downwardly facing opening in said housing.

o. Apparatus .asin claim 5 wherein said peripheral edge of said plate member is tapered inwardly and upwardly.

'7. A method of conducting off shore well-forming operations comprising: setting a pipe-like structure of uniform internal diameter vertically in a body of water with its upper end above water level; providing a vertically elongated housing of enlarged diameter havin-g coaxial openings at its upper and lower ends; releasably conn-ecting in watertight relationship the periphery of the lower opening in said housingwith the upper end of said pipelike structure at a location below the upper end of the bore of said pipe-like structure; sinking said pipe-like structure and said housing as a unit downwardly to a position in lwhich the lower end ot said pipe-like structure is embedded in the subsurface bottom, the upper end of said pipe-like structure being below water level and the upper end or said housing being above water level; carrying out well drilling operations on the subsurface bottom `from above the surface through said housing and said pipe-like structure;` withdrawing the drilling tools `from said pipelike structure and from said housing; removing 'any water from said housing and maintaining said housing tree of water; providing access for workmen, tools and equipment through said housing from above the surface; constructing a well head assembly on the top of said pipelike structure, said constructing procedure including performing operations manually at the top of said pipe-like structure from a location within said housing adjacent and above the top of said pipelike structure; and raising said housing over said well head assembly to the surface thereby leaving said well head assembly projecting abov the upper end of said pipe-like structure.

8. A method as in claim 7 further including the steps of introducing water into said housing during the sinking ot said housing and pipe-like structure into the body of water.

9. A method as in claim 7 wherein saidstep of constructing a well head assembly includes installing a production flow line extending from said assembly downwardly and then lateral-ly at a position `bellow the engagement of said housing with said pipe-like structure.

lil. A method as in claim 7 including the steps of disposing a length of pipe vertically in said housing prior to said sinking step, releasably connecting the lower end of said length of pipe to the top of said pipe-like structure, carrying out said drilling operation through said length of pipe, and disconnecting and removing said length of pipe before constructing said well head assembly.

11. A method as in claim 7 including the steps of lowering a string of casing through said pipe-like structure after a well has been drilled, providing casing suspending means on the upper end of said pipe-like structure and suspending said string of casing from the top of said pipel-ike structure.

12. A method of conducting oil? shore wel-torming operations comprising: setting a pipe having a uniform bore ertically in a body of water with its upper end above Water level; securing to the upper end of said pipe a platform having a bore coaxial with and substantially the same size as the bore of said pipe; releasably securing an open-ended cylindrical housing to said platform outward- `ly of and below the upper end of its bore in water-tight 'relationship to provide a chamber for workmen, said platform forming the lioor of said chamber; driving said pipe with said housing attached into the submerged b'ottom to a position in which the upper end of said pipe comes to rest below water level and the upper end of .said housing remains above water level; drillingr from above water level through said housing, said platform and said pipe; lowering a casing into the drilled hole and suspending the upper end of said casing from said plat-form; establishing a well head on the upper end of said casing within said chamber; and releasing and upwardly withdrawing said housing whereby said well head remains submerged and supported from the subsurface bottom by said pipe and platform.

13. A method as in claim 12 wherein said driving step includes driving said pipe wit-h said housing attached to 'a position in which said platform comes to rest below the level of the submerged bottom at a position such that said well head, when completed, lies below the level of the submerged bottom.

14. A method as in claim 12 wherein said step of establishing a well head includes drilling through said casing while maintaining mechanical control of the well above water level.

15. Off shore well apparatus comprising: a drive pipe set vertically into a submerged bottom and having its upper end below water level; a fitting secured around the upper end thereof, said fitting having an internal bore completely therethrough and having an upper, generally 'horizontal surface of sufficient area to provide a floor for workmen, said bore being coaxial with said pipe and having a substantially uniform diameter which is substantially the same as the diameter of said drive pipe, said fitting further having an annular seating sur-face disposed outwardly of said bore and outwardly of said horizontal surface; a vertical open-ended cylindrical housing of substantially uniform diameter having its lower end in releasable watertight engagement with and supported on said annular seating surface and having its -upper end projecting above the surface of the water, said pipe and said horizontal surface defining a chamber for workmen; a well head assembly arranged wholly within said cylindrical housing above said annular seating surface and above said horizontal surface, said assembly being in substantial coaxial alignment with said drive pipe and having a maximum horizontal dimension less than the diameter of lsaid housing whereby said housing may be raised over ysaid assembly to leave the same projecting above the top of said pipe.

116, Apparatus as in claim 15 further comprising a protective structure surrounding said wel-l head assem-bly and carried on the horizontal surface of said fitting inwardly of said housing.

17. Apparatus as in claim 15 further comprising a protective structure surrounding said well head assembly and carried on the horizontal surface of said fitting inwardly of said housing, the upper end of said protective structure being tapered upwardly and inwardly and the remainder being of uniform horizontal dimension, said housing having interior guide means for aligning said housing by slidably engaging said protective structure during lowering of said housing, said guide means including a ring member carried on the inner surface of said housing above the lower end thereof, the inside diameter of said ring 12 member being slightly greater than said horizontal 'dimension of said protective structure.

18; Apparatus as in claim 15 further comprising complementary fastening means on the inside of the lower end of said housing and on said generally horizontal surface inwardly of said housing for releasably fastening saidhousing to said fitting.

19. Apparatus as in claim 15 wherein said fitting includes a horizontal circular plate member having an aperture therethrough and a short length of vertical pipe, said plate member being rigidly secured to said short length of pipe with the bore of the latter-coaxial with said aperture, said bore and aperture defining the bore of said fitting, the peripheral edge of said plate member being tapered upwardly and inwardly and defining said annular seating surface.

2t). Apparatus as in claim 19 wherein said well head assembly is mounted on and supported by the upper end of said short length of pipe.

21. Ofic shore well apparatus comprising: a drive pipe structure having a bore of substantially uniform diameter, said drive pipe structure being set vertica-lly into a submerged bottom and having its upper end below water level, said upper end being defined by a horizontal plate member of substantial horizontal dimension having an aperture therethrough which communicates with the Ibore of said pipe structure, the upper end of said bore defining an upwardly facing shoulder, a first string of casing within said bore, means suspending said first string at its upper end from said shoulder; a second string of casing within said bore; a well head assembly mounted on top of said drive pipe structure above said first casing string and above said platelmember, said assembly including a casmg head suspending said second casing string and a tubing head mounted on said casing head; a well fluid production line extending from said assembly downwardly through said plate member, said plate member extending outwardly beyond the greatest horizontal dimension of said assembly and defining a fioor for workmen.

22. Apparatus as in claim 21 wherein said means suspending said l'irst casing string is a collar having an outwardly extending flange at its upper end, the upper end of said rst casing string being rigidly connected to the lower end of said collar and the lower surface of said flange resting on said shoulder, said well head assembly being connected to the upper surface of said flange.

References Cited by the Examiner UNITED STATES PATENTS 2,000,381 5/35 Duffy 166-90 2,041,394 5/36 Belcher 166-90 2,079,835 5/37 Bradley 166-75 2,562,946 8/51 Read 166-75 2,622,404 12/52 Rice 175-8 X 2,854,215 9/58 COX et al. 166-46 2,906,500 9/59 Knapp et al 166-665 3,004,602 10/61 Kofahl 175-8 X 3,062,288 11/62 Hueber 166-46 3,063,500 11/62 Logan 1664-665 3,103,976 9/63 DeVries et al 166-46 FOREIGN PATENTS 868,184 5/61 Great Britain.

CHARLES E. OCONNELL, Primary Examiner.

Claims

1. A METHOD OF CONDUCTING WELL-FORMING OPERATIONS IN WATERWHERE IT IS DESIRED TO EFFECT A WELL HEAD BLOEW THE MIUD LINE OF A SUBMERGED BOTTOM COMPRISING: SETTING A PIPE OF RELATIVELY LARGE DIAMETER SUBSTANTIALLY VERTICALLY INTO THE SUBMERGED BOTTOM WITH THGE UPPER END OF SAID PIPE ABOVE THE SURFACE OF THE WATER, RELEASABLY SECURING A VERTICALLY ELONGAGED HOUSING WHICH DEFINES A CHAMBER FOR WORKMEN AT THE UPPER END OF SAID PIPE; DRIVING SAID PIPE AND SAID HOUSING DOWNWARDLY TO A POSITIONAT WHICH THE TOP OF SAID PIPE LIES BELOW THE MUD LINE A DISTANCE SUBSTANTIALLY EQUAL TO THE HEIGHT OF WELL-COMPLETION EQUIPMENT TO BE MOUNTED ON THE TOP OF SAID PIPE AND AT WHICH THE TOP OF SAID HOUSING REMAINS ABOVE THE WATER SURFACE; CONDUCTING DRILLING OPERATIONS FROM ABOVE THE SURFACE THROUGH SAID HOUSING AND THROUGH SAID PIPE; ESTABLISHING A WELL HEAD AT THE UPPER END OF SAID PIPE WITHIN SAID CHAMBER; INSTALLING A PROTECTIVE COVER OVER SAID WELL HEAD WHILE SAID HOUSING HOLDS OFF MUD; AND SUBSEQUENTIALLY PERMITTING MUD TO SUBSTANTIALLY BURRY THE PROTRECTIVE COVER BY RELEASING AND REMOVING SAID HOUSING.