US3474858A - Method and apparatus for off shore drilling - Google Patents

Description

lBTHOD ANDPPAR'ATUS FOR vOFF ',SHORE DRILLI'NG Filed Dec. v1o, 195e Oct. 28, 1969 w. c. GIBSON r-:TAL

Sheets-Sheet l Fass/Mktl/b/k, INVENTORS. Raymond E. Thom/250,;

0th 28, 1969 w. c. GIBSON ETAL 3,474,858

METHOD AND APPARATUS FOR OFF SHORE DRILLING Filed Dec. 10, 195e 7 sheetssheet 2j,

Wilfred C. Gibson, l Foss Mc Cfl'moc, Raymand E. Thomson, uvVENToRs.-

//omsl BY Z Of- 23 1959 w. c. GIBSON ETAL 3,474,858

METHOD AND APPARATUS FOR OFF SHORE DRILLING Filed Dec. 10, 1956 '7 Sheets-Sheet 3 Y Z i:

OSf- 28, 1969 w. c. GIBSON E11-Al. 3,474,858

METHOD AND APPARATUS FOR OFF SHORE DRILLING Filed Dec. 10. 1956 F/. /84 v 47d 'A' 2a' 28 47./ l

/lz "l /fo "6 H5 /oa W/fred CG/son, Foss 'cC/mocl', Raymond E. nan/aso, v INVENTORS.

' Afford@ v 'r sheets-sheet@ Oct. 28, 1969 w. c. GlBsoN ETALl 3,474,858

I METHQD AND APPARATUS FOR OFF SHORE DRILLING Filed Dec. l0, 1956 '7 Sheets-:Sheet .5A

Ross A. Mc C/hfocl', Raymond T/lampson,

IN V EN TORS.

METHOD AND APPARATUS FOR OFF SHOREA DRILLING v I Filed D96. 10, 1956 Oct. 28, 1969 v w. 12. GlBsr'ON ETAIT 7 Sheets-Sheet 6 JNVENToRs.

/ Home] Oct 23, 1969 y y w. c. GIBSON ETAL l 3,474,858

METHOD AND APPARATUS FR OFF SHORE DRILLING Filed Dec.. 1o, 1956 7 sheets-sheet 7 W/frec/ C Gibson, /Poss Mc C/hfoc', Raymond E. Thom/asa,

1N VEN TORS,

United States Patent O 3,474,858 METHOD AND APPARATUS FOR OFF SHORE DRILLING Wilfred C. Gibson, Fullerton, Ross A. McClintock, range, and Raymond E. Thompson, Fullerton, Calif., assignors to Shaffer Tool Works, Brea, Calif., a corporation of California Filed Dec. 10, 1956, Ser. No. 627,250 Int. Cl. EZlb 15/02, 33/16, 43/01 U.S. Cl. 166-.5

This invention relates generally to the drilling of wells and relates more particularly to apparatus and Imethod for offshore drilling of wells. E

While the invention has particular utility in connection with offshore drilling of oil wells and the like, and is herein shown and described as embodied in connection therewith, it is to be understood that its utility is not limited thereto.

Where the water is shallow, the problems of offshore or underwater drilling are not diicult of solution. However, there are many dillicult problems involved in drilling in deep water and in certain localities such as the Pacific Coast, for example, the waters are relatively deep even a short distance from shore.

When the drilling is in such relatively deep water, a floating platform is used and comprises a specially equipped boat or barge which must be anchored as securely as possible, but even though the boat is securely anchored, there will be a certain amount of movement thereof due to wave and tidal action and there must be means for compensating for such movement throughout the entire drilling operation. Additional problems are involved in the locating of the wellhead and blowout preventer equipment which should be mounted as close to the ocean floor as possible.

It is, therefore, an object of the present invention to provide means and method for solving the above problems.

It is another object of the invention to provide means located close-to the ocean floor for remotely connecting and disconnecting the various equipment to the casing.

It is still another object of the invention to provide means for compensating for wave motion and to manipulate the tools used to release the safety joints.

It is a further object of the invention to provide means and method for providing a continuous connection between the casing and the lbarge for further drilling operations.

It is .a still further object of the invention to provide means and method for lowering and connecting various tools to the mandrel of the casing.

It is another object of the invention to provide means and method for releasing said tools and raising same when it is desired to do so.

When drilling oil wells with rotary drilling equipment a drilling fluid is used `and is circulated through the drill string and then pumped to screening and storage tanks. In underwater drilling operations certain problems are encountered in the handling of the drilling lluid and it is still another object of the invention to provide means for the proper handling of the drilling fluid.

It is a further object of the invention to provide means for handling the drilling uid so that such fluid will not escape into the water and contaminate same.

It is still another object of the invention to provide means and method for removing various equipment when the drilling has been completed.

The characteristics and advantages of the invention are further sufficiently referred to in connection with the Claims 3,474,858 Patented Oct. 28, 1969 vICC following detailed description of the accompanying drawings which represent a preferred embodiment of the method and apparatus or means. After considering this example, skilled persons will understand that many variations may be made without departing from the principles disclosed, and we contemplate the employment of any structures, arrange-ments or modes of operation that are properly within the scope of the appended claims.

Referring to the drawings:

FIG. 1 is a perspective undersea View showing equipment embodying the present invention;

FIG. 2 is an enlarged side view of the upper end of the casing whichhas been drilled into place and with the parts of the safety joints connected together;

FIG. 3 is an enlarged side elevation of the upper end of the landed casings with the cable anchor and weight housing attached and the upper portion of the safety joint detached from the mandrel secured to the upper end of said casing;

FIG. 4 is an enlarged elevational view showing the preventer land drilling head equipment positioned for attachment to the mandrel at the upper end of the landed casing;

FIG. 5 is an enlarged elevational view of wellhead and preventer equipment attached to the landed casing;

FIG. 6 is an enlarged elevational view showing the anchor removed from the landed casing;

FIG. 7 is a diagrammatic side view of the equipment for maintaining the guide cables under tension;

` FIG.v 8 is a diagrammatic plan view of a portion of the cable tensioning equipment;

FIG. 9 is a side View of the gate lifting sub and safety joint release tool operatively connected to a bumper sub and positioned relative to supported wellhead `and pre- Venter equipment;

FIG. 10 is a diagrammatic side view of the bumper sub release tool;

FIG. 11 is a side View of a guide rod;

FIG. 12 is an enlarged side view partially in section, showing the cement follower plug in position between the upper end of the top sub of the safety release joint and the crossover sub;

FIG. 13 is an enlarged sectional view taken on line 13-13 of FIG. 12 to particularly show the upper end of the follower plug;

FIG. 14 is a side view of the submarine drilling head with portions broken away;

FIG. 15 is an enlarged longitudinal center section taken on lines 15-15 of FIG. 2; and

FIG. 16 is a side View, partly in section, of an alternative type of submarine drilling head.

Referring to FIG. l, there is shown a boat or barge, indicated generally at 20, which is anchored at a preselected location. The anchoring means includes a plurality ofbuoys 21 attached tocables 22 from the boat or barge. There are two buoys at each end of the boat and said buoys are spaced laterally apart relative to the length of the boat or barge. From thebuoys 21 there arecables 23 leading to suitable anchors, not shown in view of the fact that any well known type of anchor may be used.

The boat is provided with anopening 25 therethrough and `amast 26 is operably dispo-sed with respect to theopening 25. Various required equipment is installed on theboat 20 and includes means for maintainingguide cables 28 under tension.

The lower ends of said cables are secured to an anchor, indicated generally at 30, removably secured to a mandrel, indicated generally at 31, of a safety release joint having a barrel, indicated generally at 32, detachably secured to said mandrel as will be described more particularly hereinafter. The upper ends of thecables 28 are wound on respective sand reel drums 34. Each dru-m has ashaft 35 mounted insuitable bearings 36, one end of said shaft having asheave 37 connected -bybelt 38 with asheave 39 of a torque converter driven by a power unit, said converter and power unit being indicated generally at 40. Each of thecables 28 pass from the sand reel drums over asheave 42 then under asheave 43 and thence over a sheave 44 and then downwardly through theopening 25 in the boat.

Above thebarrel unit 32 of the safety joint is a double cellar control gate or blowout preventer, indicated generally at 45, and above said blowout preventer is apreventer 46. Above thepreventer 46 is a submarine drilling head, indicated generally at 47.

The drill string is indicated generally at 50 and passes through thehead 47 `andpreventers 46 and 45 as shown in FIG. 4 The upper end of the drill string is connected in the usual manner to equipment of well known character for rotating the drill string and otherwise manipulating same. Pressure for operating the preventers and/or other equipment below the boat or barge is supplied through various conduits secured together to form a sheaf, indicated generally at 52, which extends from suitable equipment on the boat downwardly to the door of the ocean or other body of water, said botto-m being indicated at 33. The sheaf rests on said bottom 33 to prevent it from being whipped about by the currents.

Drilling fluid of any suitable type is circulated through the equipment used for rotary drilling and the circulatory system thereof will be described more particularly hereinafter.

Preparatory to the drilling of a well according to the process or method of the present invention, an equipped ship or barge is floated to the preselected location where the drilling is to be done. The ship is then suitably anchored by any well known arrangement such as, for example, that described hereinabove.

The first phase of the underwater drilling operation comprises the setting of surface pipe so that mud circulation can be established and blowout prevention equipment installed.

Sufficient casing to drill through ocean bottom sediments intosolid formations 33a is assembled in the usual operating equipment on the boat. At the bottom of the casing is a bit similar to a washover shoe of known character and a drillable bar, or core wiper is provided across the face of the bit to prevent a core from forming in the casing. A conventional float shoe may also be inserted in the string above the bottom joint. The bit, core wiper and float shoe may be of standard construction as used in the ordinary drilling procedures, as for example, the equipment and procedures outlined in the book, Petroleum Production Engineering, Third edition, by Lester Charles Uren, published by McGraw-Hill Book Company, Inc., 1946.

When the desired length of casing has been assembled, a casing safety joint of the correct size is assembled at the upper end of said assembled casing. By way of example, safety joints such as disclosed in the Kenneth E. Waggener application for Torque Releasing, Safety Joint for Well Tool Strings, Ser. No. 390,321, tiled November 5, 1953, now US. Patent No. 2,893,694, may -be used. The safety release joint provides means for remotely disconnecting or connecting the casing during later operations.

Above the safety joint is acrossover sub 60, said crossover sub being connected at its lower end to the upper end of thebarrel unit 32 of the safety jo'mt, said crossover sub tapering to a reduceddiameter portion 61 which is connected to theadjacent drill tubing 62. This arrangement provides means for reducing to the drill tubing size.

At the upper end of the barrel unit of the safety joint,

the device is provided with the usual internally threaded taperingsocket 64 and at the lower, smaller diameter end of thesocket 64 there is ashoulder 65 on which is seated aring 66 which is held in position by the lower, smaller diameter end of thepin 67 of thecrossover sub 60.Ring 66 supports a cement follower plug, indicated generally at 70. The cement follower plug comprises atube 71 having a plurality of wipingelements 72 of suitable resilient material such as a synthetic rubber or the like and said elements are secured to thetubular body 71 in longitudinally spaced relationship thereof by any suitable means such as a bonding process of well known character. Thetubular body 71 of the follower plug is axially disposed and the upper end thereof is provided with radial openings arranged to register with radial openings provided in thering 66 and in which are disposed shear pins 74. The inner ends of the shear pins do not extend into thecentral passage 75 of thetubular body 71, saidpassage 75 allows circulation of the drilling fluid during drilling-in operations.

The part of the drill string indicated at `62 comprises a drilling bumper sub, a device well known in the well drilling art, the upper end of which has attached thereto drilltubing 80. The functions ofdrilling bumper sub 62 are to provide compensation for wave motion and to manipulate the tools used to release the safety joint as will be described more fully hereinafter. Where necessary, additional bumper subs may be used in the string above thebumper sub 62 where wave motion is greater than the capacity of a single bumper sub unit,

A groove 82, FIG, l, is provided adjacent the lower end of the mandrel to accommodate a depth control member, indicated generally at 83, which comprises a pair ofsemicircular plates 84 which are secured together by rivets 85 or by any other suitable means Such as welding or the like. Theelement 83 functions as a stop for the casing after sufficient hole has been cut to bring said element into contact with the ocean floor.

Themandrel 31 is connected to the upper end of thecasing string 88. When the casing has been drilled into place, cementing operations are started. These are carried out along conventional lines, that is, the cement is pumped down the drill string until the necessary volume has been inserted, it being noted that the cement passes through thetubular body 71 of the cement follower plug. Above the kelly there is a side door kelly cock in the drill string which permits access to the mud circulating system without danger of backow. After the mud has been added, the kelly cock is opened and a ball is inserted therein. The ball is pumped down the string until it seats on the upper end of the cement follower plug -body 71, said ball being indicated in FIG. 12 at 92. Seating of the ball closes thepassage 75 through the cement follower plug so that pump pressure above said ball and plug increases until the pi'ns 74 are sheared. Thereafter, the pressure above said plug and ball force said plug down the casing until it seats in the float shoe in a manner well known in the drilling art. A second increase in mud pump pressure will indicate that the plug has reached this position. The cement, which has gone down through the string and casing and up about the outside of the casing to the approximate level of the ocean floor, is allowed to set the usual period necessary to insure good bond and strength.

After the cement has hardened, and before releasing the safety joint and continuing drilling operation, a continuous connection between the casing and barge is effected. The means for providing such connection comprises thecables 28 and the weight housing oranchor 30.

Weight housing oranchor 30 comprises a tubular -body of such internal diameter as to readily accommodate thebarrel unit 32 of the safety joint and to slide thereover. At the upper end of said tubular body there is an outwardly flaring funnel shapedmember 101 which may be integral with thebody 100 or which may be a separate piece secured to said body by Welding, brazing or by any other suitable means. Concentrically disposed about saidbody 100 is a tubular reinforcingsupport 102, the lower end of said support being in substantially the same plane as the lower end of said body, the upper end of said support contacting the underside of thefunnel 101 and being secured thereto by any suitable means such as brazing, Welding or the like. At the upper end of the Weight housing oranchor 30 are a pair of oppositely extendingradial arms 104 secured at their inner ends to thefunnel portion 101 of said anchor and having at their respective outer ends a pair ofears 105 secured thereto and spaced apart longitudinally with respect to their respective arms. Pivot pins 105 are supported by the respective pairs of ears at the ends of said arms and cable clamps 106 at the respective ends of saidcables 28 are pivotally attached to said pins 105. Adjacent the lower end of the tubular body there is alongitudinally extending notch 108 at the side of which are outwardly extendingears 109.Ears 109 carry apivot pin 110 on which is pivotally mounted a latch member, indicated generally at 111. Latch member 111 has an upwardly extendingarm 112 and at the lower end of said member there is an inwardly projecting boss ordetent 114 which extends through theslot 108 and is adapted to enter an externalannular groove 115 in themandrel 31 above theplates 83, A Wire spring or other suitable type of spring 116 coiled about thepivot pin 110 is provided, the ends of said spring reacting between thetubular body 100 and themember 112 to urge said detent orboss 114 into saidgroove 115. In order to facilitate assembly of the anchor about the drill string, said anchor comprises a .pair of complementary parts or halves and the parts are `divided longitudinally at diametrically opposite sides which are at substantially right angles to thearms 104. The line of division is thus shown in FIG. 5 at 120 and there are outwardly extendingflanges 121 along said lines of division. Theflanges 121 are provided with registering openings for reception ofscrews 122. Thus, when the anchor of weight housing is attached the two parts are put together about the drill string and thescrews 122 are inserted and tightened. The anchor is then lowered until the latch 111 engages thegroove 115 t0 thereby lock said anchor securely to the mandrel.

As above pointed out, the upper ends of said cables are wound on the sand reel drums which are connected to torque converters. With this arrangement the cables may be maintained under proper tension but will wind and unwind on said sand reel drums with the motion created by the waves and tide. There are, of course, other methods for maintaining tension on said cables. The cables thus provide a connection between the casing and the barge or boat and also serve as guides to locate equipment on the wellhead as said equipment is lowered into place.

After the casing has been drilled in, the cementing operation completed and theanchor 30 attached, the barrel unit of the safety joint is released. Where the safety joint used is similar to that disclosed in United States Patent No. 2,893,694 to Waggener, a releasing tool, indicated generally at 130, FIGS. 3 and l0, may be utilized to effectuate a disconnection. This tool comprises anelongated bar 131 having anenlarged head 132 at its upper end and a pair ofprongs 133 at its lower end.Prongs 133 are pivotally connected at their lower ends to said bar and are urged outwardly 'by means of springs or the like. Similar kinds of releasing tools are well known in the drilling art and the specific form illustrated is not to be considered part of this invention. It is to be understood, of course, that there may be other means for effecting release of a barrel unit from its mandrel, the form of the releasing tool depending upon the safety joint construction.

To effect release of the Waggener type safety joint thetool 130 is inserted in the bore of the drill tubing at the derrick floor. The bar falls down the bore in the tubing until thehead 132 seats on shoulder 62a in the top of thedrilling bumper sub 62 as shown in FIG. 15. The prongs orfingers 133 engage a groove in the locking sleeve of the barrel unit of the safety joint when the drilling bumper sub is closed or substantially closed. Upward movement of the drilling string will then open the drilling bumper sub and move the locking sleeve in the safety joint to a releasing position. Continued upward pull on the safety joint barrel unit causes same to disconnect from the mandrel. When the barrel unit has been separated from the mandrel, as shown in FIG. 3, the drilling string can then be raised to the surface, and preparations for installing the preventer started.

In preparation for the drilling of the main hole, the subsea control unit is made up, this unit comprising thedrilling head 47, aspool 135 with a side outlet 136 (FIG. 5) to which areturn mud line 137 is attached, thepreventer 46, and the doublehydraulic preventer 45. A safetyrelease barrel unit 32 is attached to the lower end of the `dou-ble preventer 45 as best shown in FIGS. 1, 4 and 5.

Thedrilling head 47 may be of any well known type which provides a seal with the drilling string so that fluid cannot escape about said string. Thus, the fluid circulated during the drilling operations and pumped down the drill string and then upwardly about said string cannot escape past thehead 47 and is forced to leave by way of theside outlet 136 of the.spool 135 and thence upward to the boat or barge 'by Way of theiiow line 137 which leads to and discharges into atank 140, FIG. l. A plurality of tanks may be used and motor driven rapid mixers of known type provide the means for mixing the uid in said tank. The mixed fluid is pumped from the tank or tanks and -into the drill string thus maintaining circulation through the equipment during drilling operations.

Preventer 46 is of a type adapted to pack off various types of equipment disposed therein. This preventer is adapted to pack off tools joints, pipe of different sizes, and the open hole. Bag types of preventers, known in the art, will perform these functions.

The double hydrauliccontrol gate preventer 45 includes a pair of opposed complete shutoff ram blocks 142, only one of said blocks being shown in FIG. 4. Each of these blocks is actuated hydraulically by means of apiston 143 operably disposed in acylinder 144 and connected with said ramr blocks by means of a connectingrod 145. Hydraulic fluid under pressure is admitted to one side or the other of thepistons 143 so as to cause same to move theblocks 142 toward each other or away from each other to close or open the passage through the preventer when no equipment or pipe is disposed in said passage. Above the complete shutoff blocks 142 are a pair of oppositely arranged ram blocks 147, said ram blocks 147 are provided with semicircular recesses in their adjacent faces to accommodate a pipe or the like disposed in the said passage of thepreventer 45. Theblocks 147 are movable toward and away from each other by means ofrespective pistons 148 operably disposed incylinders 149 and connected to therespective block 147 by means of connectingrods 150. Fluid or hydraulic pressure is admitted to one side or the other ofpistons 148 to effect movement of theblocks 147 t0- ward and away from each other to engage or disengage a pipe disposed in the passage of said preventers. Hydraulic pressure is transmitted from suitable pressure creating equipment, not shown, of well known pipe located on the barge by way of the conduit of thesheave 52. Valves, also not shown, of any 'well known type are used to control the pressure from said pressure creating equipment to the particular side of the pistons of the respective ram blocks. In FIG. 1 the conduits 154 are connected with theblowout preventer 45.

Conduits are connected to thepreventer 46 to supply pressure for operating said preventer between the open position and a closed or engaging position.

Atypical drilling head 47, as shown in FIG. 14, is provided with a sealing sleeve which is stripped over the string before the bit is attached thereto and is carried down with the string until it enters the funnel shapedend 47a of the casing 47h. The sleeve is held in sealing engagement with the drill string by means ofsegments 162, which are urged inwardly bypistons 163 on connectingrods 165 connected with said segments. Thepistons 163 are supplied With operating pressure by means ofconduits 168, the pressure to which is also controlled by valves on the boat. When drilling operations are under way thesleeve 160, which is of any suitable material such as a synthetic rubber that will resist the action of fluid and the like to which it is exposed is locked in position bySaid segments 162. However, when it is desired to remove the string, thesegments 162 are released by pressure applied to the other side ofpiston 163 to permit removal of the bit from the equipment as said bit is too large to pass through the sleeve and hence carry same upwardly as the bit is removed. Pressure may be applied to the space 160a behind thesleeve 160 through conduit 16011 from any suitable source to press said sleeve against the string therein.Sleeve 160 not only prevents escape of circulating iluid but also prevents entrance of external water into the system.

In some installations, it is desirable to have a mud cross, indicated generally at 170. The cross may be of any Well known type and has conduit connections 172. The cross is adapted to function in the well known manner for example, the said cross may be used for relieving pressure or to kill the well should such action become necessary. Across 170 is shown in FIG. l but is not included in the arrangement shown in FIGS. 4 and 5.

The assembly equipment also includes aflange sub 175 having aange 176 having openings therein spaced annularly apart for reception of screws orbolts 177 4whereby said flange sub is attached to the lower end of thepreventer 45. The flange sub is provided with the usual externally threaded pin, not shown, for attachment to the upper end of a safety joint barrel unit shown in FIGS. 1, 2 and 3 and hence will be given the same reference numeral, that is,reference numeral 32.

Means are provided whereby the assembled equipment may be guided by theguide cables 28 as said equipment is raised and lowered. This means includes arms connected to certain portions of the equipment and extending outwardly to slidably receive said guide cables adjacent the outer ends of said arms. More particularly, one pair of arms, indicated at 180, are formed integrally with theflange 176. These arms extend outwardly of the flange at diametrically opposite sides thereof and are provided with openings adjacent their free ends in which theguide cables 28 are slidably received. It is to be understood, of course, that thearms 180 may be otherwise secured to said flanges or may be otherwise attached to the assembly adjacent the lower ends thereof. At the upper end of the assembly, a pair of diametrically arrangedarms 184 extend outwardly fromfunnel 47a and are provided adjacent their outer ends with respective openings for slidable reception of theguide cables 28. Thus, guide means are provided adjacent the top and bottom ends of the assembled equipment. It is to be understood, of course, that additional arms may be provided to connect other parts of the assembled equipment with said guide cables.

With thepreventers 45 and 46,spool 135, andhead 47 assembled into a unit said unit is lowered and connected to themandrel 31. In order to support the unit while lowering same into position, a setting tool, indicated generally at 185 (FIG. l1), is used. This tool is elongated and has a roundedleading end 187. Adjacent the opposite end there is an external annular recess orgroove 188. Thetool 185 is connected to the lower end of a string as at 189 and said tool is inserted into the upper end of the assembled unit and positioned so that thegroove 188 is engageable by therams 147. The rams are closed on the tool and enter said groove so as to engage the inner reduceddiameter portion 190 of tbe tool. The entire unit is then supported by theshoulder 191 at the lower end ofgroove 188 and the unit thus lowered with the Weight supported by said shoulder. It is to be understood, of course, that thearms 180 and 184 are connected to theguide cables 28 so that the unit is guided downwardly thereby. As the lower end of thetool 185 extends below the lower end of thebarrel unit 32, said lower end of the tool serves as a guide which enters the bore of the mandrel and guides the safety joint barrel unit over said mandrel. While thecables 28 guide the above referred to unit of assembled equipment, thefunnel 101 also functions as a guide should the lower end of the equipment unit become displaced for any reason out of alignment with respect to the mandrel. After thebarrel unit 32 has been locked on themandrel 31, theupper rarns 147 of thepreventer 45 are actuated to the open position thereby releasing thetool 185 which is then raised along with the drill string to which it is attached.

The safety joint disclosed herein is similar to the kind taught by Waggener in United States Patent No. 2,893,- 694, having a reciprocated locking sleeve that prevents separation of the barrel and mandrel until said locking sleeve is retracted.

Following the removal of the blowout preventer setting tool, the drilling bit is asse-mbled on the drill collars with the rotating packer or sleeve of thehead 47 stripped on directly above it. A bit guide is mounted above the packer and comprises acollar 200 comprising a pair of semicircular complementary parts which may be hinged at one side and secured at the other side by means of a latch or screw, not shown. Thecollar 200 is provided with an axial opening in which the drill pipe is slidably received and said opening is sutlciently large to permit passage therethrough of drill collars such as indicated at 201. Thecollar 200 is provided with outwardly extending arms '203 having openings adjacent their outer free ends for slidable reception of theguide cables 28. The bit with the guide disposed above it is then lowered, said bit entering thefunnel 47a and passing downwardly through thehead 47,spool 135,preventer 46, mud cross in the assembly shown in FIG. 1,preventer 45, and on down- Wardly through the safety release joint and into thecasing 88.

As the bit enters the equipment unit, the rotating packer or seal 160 in thehead 47 is seated therein and hydraulic pressure is applied to thepistons 163 to thereby lock said packer in place. If mud pump pressure is applied through the drill string at this time, it can be determined that the packer is correctly locked. The return of mud through theflow line 137 will indicate that the packer is correctly installed.

The cement may be drilled out and the well drilled in the conventional manner. The drilling bumper sub used during the preventer setting operation may be used during drilling operation to compensate for waves and tide motion.

In order to keep theguide cables 28 under proper tension, the torque converter of theunit 40 is set in the stall position, upward motion of the barge resulting in more lines automatically being spooled off thedrum 34 while descending motion causes the line to be reeled in.

When the drilling bit becomes dull or it is desired to remove it from the hole, it is raised until in the area between the blind or complete shutoff rams 142 and the rotating packer. The rams are closed to prevent sea Water from entering the hole and the rotating packer orsleeve 160 is released by moving thesegments 162 to the release position. The drill string may now be raised to the surface.

When the hole has been completed and it is necessary to remove the equipment unit, a special tool orgate lifting sub 210, FIG. 9, is used. Thetool 210 is secured to the lower end of abumper sub 62 which has its opposite end secured to apipe string 189. The gate lifting sub is lowered until it touches theblind rams 142 which were closed prior to removal of the bit, saidgate lifting sub 210 having an external annular recess or groove 212 therein which, when the lower end of said gate lifting sub rests on the blind rams, is located in the path of the pipe rams 147 which are closed to engage the reduceddiameter portion 214 at the bottom of saidrecess 212.

Thereafter, theblind rams 147 are opened and a safetyjoint release tool 215, such as may be used for releasing a Waggener type safety tool joint, can then be inserted in the bore of the tubing on which the gate lifting sub is attached.Tool 215 has a head similar to thehead 132 of thetool 130 and said head is adapted to seat on the shoulder 62a,in the upper part of the drilling bumper sub l62 which is directly above thegate lifting sub 210. This -releasingtool 215 extends downwardly below the gate lifting sub and adjacent the lower end is provided withfingers 216 similar to the lingers 133 of the releasingtool 130. When the bumper sub is substantially telescoped, thefingers 216 are positioned in the barrel unit of the safety joint so that when upward movement of the pipe string is effected with corresponding upward movement of the upper end of said bumper sub, thetool 215 will be raised and thefingers 216 will engage a shoulder within lthe key sleeve, not shown but substantially the same as that taught by Waggener in United States Patent No. 2,893,694, of the safety tool joint. Upon further upward movement of the pipe string, the bumper sub will be further extended and the key sleeve retracted to effectuate a release and allow the barrel and mandrel to be separated. Thereafter, when the bumper sub becomes fully extended, the equipment unit is raised to the surface, theshoulder 218 at the lower end ofrecess 212 of the gate lifting sub carrying the weight of the equipment unit as said unit is raised. Because the mandrel remains in place it will be apparent that should it be desired t reconnect the barrel to said mandrel, such reconnection may be effected.

After the drilling operation has been completed and the equipment unit raised, the cable and weight housing or anchor can be removed. A pull of adequate magnitude, such as five or six tons, for example, releases the anchor from themandrel groove 115 so that the anchor may be raised to the surface.

In FIG. 16 an alternative type of submarine drilling head is disclosed. In this arrangement, there is asleeve 225 to the outside of which is secured acollar 226 by means of asnap ring 227, said collar having an annularexternal recess 228. At the lower end of thesleeve 225 is astripper rubber 230 of known character adapted to sealingly engage the string disposed therewithin. Thesleeve 225 and thestripper rubber 230 are attached to the string in a manner similar to the attachment of the corresponding part above described in connection with thehead 47. When thestripper rubber 230 andcollar 225 are seated in thecasing 232 of the head, pressure from aconduit 168 is supplied to the outer side of pistons 233 which are carried byplungers 234, the latter then being forced inwardly into thegroove 228 to thereupon securely hold thesleeve 225 andrubber 230 in position. There are a plurality of annularly spaced plunger and piston devices and said plungers are |held inwardly by pressure supplied through the respective conduit 16'8. Theplungers 234 are urged outwardly to release thesleeve 225 by pressure supplied by arespective conduit 168 to the opposite sides of said pistons 233. Theplungers 234 are urged outwardly byrespective springs 235 in ahousing 236, said springs reacting againstWashers 237 secured to the outer ends of the plungers byscrews 238. Thus, should the pressure to the pistons 233 fail, theplungers 234 will be urged outwardly to effect release of thesleeve 225 so that the drill string may be removed.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it is thought that it will be apparent that various changes may be made in the form, construction, arrangement of the parts of the invention and steps of the method thereof, without departing from the spirit and scope of said invention or sacrificing all of its material advantages.

We claim:

1. In combination with a Well drilling string, apparatus for drilling a well in a formation under water, comprising: a floating support; means for anchoring said support; a casing positioned in said formation and having its upper end substantially at the surface thereof said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; flexible guides secured to and extending between said anchor device and said support; a vertical assembly of series connected drilling devices including a submarine head, a control gate having a gate ram and a safety release joint barrel unit, said unit Ibeing matable with said mandrel, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing off said drill pipe passageway; means on said assembly for slidable engagement with said flexible guides; and means including connections and apparatus extending from said support for operating said submarine head and said control gate.

2. In combination with a well drilling string, apparatus for drilling a well in a formation under water, comprising: a floating support; means for anchoring said support; a casing positioned in said formation and having its upper end substantially at the surface thereof said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; flexible guides secured to and extending between said anchor device and said support; a vertical assembly of series connected drilling devices including a submarine head, a control gate having a gate ram, and a safety release joint barrel unit, said unit being matable with said mandrel, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing olf said drill pipe passageway; means on said assembly for slidable engagement with said flexible guides; means including connections and apparatus extending from said support for operating said submarine head and said control gate; and means for lowering and raising said assembly from and to said support.

3. In combination with a well drilling string, apparatus for drilling a well in a formation under water, comprising: a floating support; means for anchoring said support; a casing positioned in said formation and having its upper end substantially at the surface thereof said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; flexible guides secured to and extending between said anchor device and said support; a vertical assembly of series connected drilling devices including a submarine head, a control gate having a gate ram, and a safety release joint barrel unit, said unit being matable with said mandrel, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing olf said drill pipe passageway; means on said assembly for slidable engagement with said flexible guides; means including connections and apparatus extending from said support for operating said submarine head and control gate; and means engageable by a ram of said gate for supporting said assembly from said support.

4. In combination with a well drilling string, apparatus for drilling a well in a formation under water, comprising: a floating support; means for anchoring said support; a casting positioned in said formation and having its upper end substantially at the surface thereof, said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; guide cables secured to and extending between said anchor device and said support; means on said support for yieldingly maintaining said cables under tension; a vertical assembly of Series connected drilling devices including a submarine head, and a control gate having a gate ram, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing olf said drill pipe passageway; a safety release joint barrel unit connected to the lowermost of said assembly devices and being matable with said mandrel; means on said assembly for slidable engagement with said cable; and means including connections and apparatus extending from said support for operating said submarine head and said control gate.

5. In combination with a well drilling string, apparatus for drilling a well in a formation under water, comprising: a oating support; means anchoring said support; a casing positioned in said formation and having its upper end substantially at the surface thereof, said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; guide cables secured to and extending between said anchor device and said support; means on said support for yieldably maintaining said cables under tension; a vertical assembly of series connected drilling devices including a submarine head, and a control gate having a gate ram, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing off said drill pipe passageway; a safety release joint barrel unit connected to the lowermost of said assembly devices and being matable with said mandrel; means on said assembly for slidable engagement with said cable; means including connections and apparatus extending from said support for operating said submarine head and said control gate; and means for lowering and raising said assembly from and to said support.

6. In combination with a well drilling string, apparatus for drilling a well in a formation under water, comprising: a oating support; means anchoring said support; a casing positioned in said formation and having its upper end substantially at the surface thereof, said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; guide cables secured to and extending between said anchor device and said support; means on said support for yieldingly maintaining said cables under tension; a vertical assembly of series connected drilling devices including a submarine head, and a control gate having a gate rarn, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing off said drill pipe passageway; a safety release joint barrel unit connected to the lowermost of said assembly devices and being matable with said mandrel; means on said assembly for slidable engagement with said cable; means including connections and apparatus extending from said support for operating said submarine head and said control gate; a pipe string projected from said support; and a setting tool for said assembly, said tool adapted for being connected to the projected end of said string and having an external recess for receiving a gate ram of a control gate.

7. In combination with a well drilling string, apparatus for drilling a well in a formation under water, comprising: a floating support; means anchoring said support; a casing positioned in said formation and having its upper end substantially at the surface thereof, said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; guide cables secured to and extending between said anchoring device and said support; means on said support for yieldingly maintaining said cables under tension;

a vertical assembly of series connected drilling devices including a submarine head, and a control gate having a ram, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing olf said drill pipe passageway; a safety release joint barrel unit connected to the lowermost of said assembly devices and being matable with said mandrel; means on said assembly for slidable engagement with said cable; means including connections and apparatus extending from said support for operating said submarine head and control gate; a pipe string projected from said support; and a setting tool for supporting said assembly at the projected end of said string said tool including a body portion having an external recess for receiving a gate ram of a control gate and being of sufficient length to protrude outwardly from said barrel unit when engaged by said gate ram.

8. In combination with a well drilling string, apparatus for drilling a well in a formation under water, comprising: a floating support; means anchoring said support; a casing positioned in said formation and having its upper end substantially at the surface thereof said casing being sealingly cemented in said formation; a safety release joint mandrel secured to the upper end of said casing; an anchor device releasably secured to said casing; guide cables secured to and extending between said anchor device and said support; means on said support for yieldingly maintaining said cables under tension; a vertical assembly of series connected drilling devices including a submarine head, and a double cellar control gate having spaced upper and lower gate rams, said assembly defining a drill pipe passageway and said gate ram being operable into a position closing off said drill pipe passageway; a safety release joint barrel unit connected to the lowermost of said assembly devices and being matable with said mandrel; means on said assembly for slidable engagement with said cable; means including connections and apparatus extending from said support for operating said submarine head and control gate; a pipe string projected from said support and a lifting tool for supporting said assembly at the projected end of said string, said tool including a tubular body, said body having an external annular groove, the lower side of said groove being spaced from the leading end of said tool a distance equal to the spacing between the upper surface of said lower ram and the lower surface of said upper ram; whereby said groove will be positioned opposite the upper gate ram when said tool is fully projected into the upper end of said control gate and while said upper gate ram is opened and said lower gate ram is closed, said tool then engaging the upper surface of said lower rarn.

9. A lifting tool for a double cellar control gate having spaced upper and lower gate rams, said tool being adapted for connection to the end of a string and comprising: a body adapted to be passed into said gate, said body having a recess therein, the lower side of said recess being spaced from the leading end of said tool a distance equal to the spacing between the upper surface of said lower ram and the lower surface of said upper ram; whereby said recess will be positioned opposite the upper gate ram when said body is fully projected into the upper end of said control gate and while said upper gate ram is opened and said lower gate is closed, said tool then engaging the upper surface of said lower ram.

10. A lifting tool for a double cellar control gate having spaced upper and lower gate rams, said tool being adaptd for connction to the end of a string and comprising: a tubular body adapted to be passed into said gate, said body having an external annular groove the lower side of said groove being spaced from the leading end of said tool a distance equal to the spacing between the upper surface of said lower ram and the lower surface of said upper ram; whereby said groove will be positioned opposite the upper gate ram when said body is fully projected into the upper end of said control gate and while References Cited UNITED STATES PATENTS McNeill Z55-2.5 Bauer et al. Z55-2.5 Howard 166-47 Tucker Z55-2.5

14 2,891,770 v6/1959 Bauer et al. Z55- 2.5 X 2,912,214 11/ 1959 Allen et a1. 255-19 2,923,531 2/1960 Bauer et al. Z55- 2.5

CHARLES E. OCONNELL, Primary Examiner R. E. FAVREAU, Assistant Examiner U.S. C1. X.R. 175-7

Claims (1)

1. IN COMBINATION WITH A WELL DRILLING STRING, APPARATUS FOR DRILLING A WELL IN A FORMATION UNDER WATER, COMPRISING: A FLOATING SUPPORT; MEANS FOR ANCHORING SAID SUPPORT; A CASING POSITIONED IN SAID FORMATION AND HAVING ITS UPPER END SUBSTANTIALLY AT THE SURFACE THEREOF SAID CASING BEING SEALINGLY CEMENTED IN SAID FORMATION; A SAFETY RELEASE JOINT MANDREL SECURED TO THE UPPER END OF SAID CASING; AN ANCHOR DEVICE RELEASABLY SECURED TO SAID CASING; FLEXIBLE GUIDES SECURED TO AND EXTENDING BETWEEN SAID ANCHOR DEVICE AND SAID SUPPORT; A VERTICAL ASSEMBLY OF SERIES CONNECTED DRILLING DEVICES INCLUDING A SUBMARINE HEAD, A CONTROL GATE HAVING A GATE RAM AND A SAFETY RELEASE JOINT BARREL UNIT, SAID UNIT BEING MATABLE WITH SAID MANDREL, SAID ASSEMBLY DEFINING A DRILL PIPE PASSAGEWAY AND SAID GATE RAM BEING OPERABLE INTO A POSITION CLOSING OFF SAID DRILL PIPE PASSAGEWAY; MEANS ON SAID ASSEMBLY FOR SLIDABLE ENGAGEMENT WITH SAID FLEXIBLE GUIDES; AND MEANS INCLUDING CONNECTIONS AND APPARATUS EXTENDING FROM SAID SUPPORT FOR OPERATING SAID SUBMARINE HEAD AND SAID CONTROL GATE.

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