US3163220A

US3163220A - Underwater well drilling apparatus and method

Info

Publication number: US3163220A
Application number: US105970A
Authority: US
Inventors: John A Haeber; Lloyd G Otteman
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1961-04-27
Filing date: 1961-04-27
Publication date: 1964-12-29
Anticipated expiration: 1981-12-29
Also published as: GB940758A

Description

1964 .1. A. HAEBER El'AL 3,163,220

UNDERWATER WELL DRILLING APPARATUS AND METHOD Filed April 27, 1961 s sheets-sheet l INVENTORS J. A. HAEBER L.G. OTTEMAN BY H k Cbh HEIR AGENT Dec. 29, 1964 J. A. HAEBER ETAL 3,163,220

UNDERWATER WELL DRILLING APPARATUS AND METHOD Filed April 27, 1961 3 Sheets-She et 2 FIG. 2 FIG. 2A

FIG. 3

INVENTORS:

J. A. HAEBER L. e. OTTEMAN BY: 'Q

HEIR AGENT Dec. 29, 1964 J. A. HAEBER ETAL UNDERWATER WELL DRILLING APPARATUS AND METHOD Filed April 27. 1961 3 Sheets-Sheet 5 INVENTORS:

F I G. 4

United States Patent 3,163,220 nrsnnnwarnn i our. onurrno Annamaria AND Mari-son John A. Haeher and Lloyd G. Otteman, Houston, Tern, assignors to Shell (iii tlonipany, New York, N31, a corporation of Delaware Filed Apr. 27, E961, Ser. No. W537i '7 tilairns. (Ql. t es-as This invention relates to apparatus for use during the drilling of offshore wells and pertains more particularly to apparatus adapted to be positioned in the bore of the well casinghead for protecting the seating surfaces thereof.

In an attempt to locate new oil fields an increasing amount of well drilling has been conducted at ofishore locations, such for example, as ofi the coast of Louisiana, Texas, and California. As a general rule, the strings of casing in a well together with the tubing string or strings extend to a point well above the surface of the water where they are closed in a conventional manner that is used on land wells, with a conventional wellhead assembly being attached to the top of the casing. Attempts have recently been made to provide methods and apparatus for drilling and completing a well wherein both the well casinghead and subsequently the wellhead assembly and casinghead closure device are located underwater at a depth suificient to allow ships to pass over them. Preferably the casinghead and wellhead closure assemblies are located close to the ocean floor. In order to install equipment of this type underwater in depths greater thanthe shallow depth at which a diver can easily operate, it has beennecessary to design entirely new equipment for this purpose. Thus, when drilling and completing an oil or gas well at an offshore location in a manner described in copending patent application Serial No. 830,538, filed July 30, 1959, and entitled Underwater Well Completion Method, the well casing may have attached thereto, equipment in accordance with the present invention.

During the drilling of a land well, the casinghead to be used thereon is normally put together as the drilling progresses. A land casinghead normally comprises a plurality of spool pieces each having a landing surface therein for seating a pipe hanger from which a string of well cas ing or tubing would be suspended. Thus, after drilling a predetermined depth of hole of one diameter, a landing spool piece is flanged to the top of the conductor pipe in the ground and a string of well casing is run through the spool piece and hung on the landing surface thereof. Drilling operations are then continued with a smaller size 'bit which runs through thewell casing previously hung.

However, in the drilling of underwater wells from a retubing suspension body which may be a unitary structure,

if desired. It may be seen that a casinghead and/or its casing and tubing suspension body, which is capable of ventional manner.

seating numerous concentric strings of pipe, will have a v plurality of landing surfaces some of which will be exposed to the circulation of drilling fiuid and to wear do to the rotation of a drill stem therein.

It is therefore a primary object of the present invention to provide a method and apparatus for drilling a well through a casinghead wherein the landing surfaces therein are protected against wear caused by a rotating drill string or by the circulation of a drilling fluid.

Another object of the present invention is to provide apparatus adapted to be inserted into a casinghead and seated on one of the landing surfaces thereof while at the same time the apparatus is locked against rotation so that it does not damage the landing surface on which it is seated.

A further object of the present invention is to provide a method for flushing out a drilling well casinghead so as to remove therefrom apparatus which was inserted to protect the landing surfaces of the casinghead.

These and other objects of this invention will be understood from the followingdescription taken with reference to the drawing, wherein: V

FZGURE l is a diagrammatic view illustrating a floating drilling barge anchored to the ocean floor over a drilling location during drilling operations;

rrouans 2 and 2A are views taken in longitudinal cross-section of a casinghead provided with a wear sleeve in accordance with the present invention and having mounted on the outside thereof a wellhead connector which is shown in its operative position in FIGURE 2A, and in its inoperative position in FIGURE 2; FIGURE 3 is a view taken in partial longitudinal crosssection of a running tool for removing and/orinserting the wear sleeve from a well casinghead; 1

FIGURE 4 is a view taken in partial longitudinal crosssection of another form of a wear sleeve positioned in another casinghead arrangement in accordance with the present invention; 7

FIGURE 5 is a fragmental view taken in cross-section along line 5 of FIGURE 2; and 1 FIGURE 6 is a longitudinal viewof a wash string having a dumb-bell type packer positioned at the lower end thereof. 7

Referring to FIGURE 1 of the drawing, a drilling barge 11 of any suitable fixed or floatable type is illustrated as floating on the surface of the water 12 and substantially fixedly positioned over a preselected drilling location, as

being anchored to the ocean floor 13 by

anchor lines

14 and 15 running to anchors (not shown) sunk in the ocean floor. Equipment of this type may be used when carrying out welldrilling, well-completion, or well-maintenance operations in water varying from about to 1500 feet or more in depth. The drilling barge is equipped with a suitable derrick 15 containing fall lines 17 and a hoist 18, l

as well as a rotary table 19 and other auxiliary equipment needed during the drilling or servicing of a well. Thus, in this instance the derrick to is shown as being provided with a traveling block 21 to which is secured elevators 22 or other suitable means for suspending a drill string 23 during drilling operations. A flexible hose 24 is provided and is adapted to be secured to the top of the drill string 23 by means of a swivel (not shown) of a conventional type whereby drilling fluid may be circulated down through the drill string 23 during the drilling operation, The flexible hose 24 is in communication with a pump 25 which is adapted to circulate the drilling mud.

The derrick To: is positioned over a drilling slot or well 26 which extends vertically through the barge 11 in a con- When using the equipment of the present invention, the slot 25 in the barge 111 may be either centrally located or extended from one edge. I-low- 7 ever, operations with the apparatus of the present inven- '3 tion may be carried out over the side of the barge without use of a slot.

A wellhead support structure, which is represented by a horizontally extending support base 27, having a casinghead 28 secured thereto and centrally positioned thereon, is illustrated as being anchored to the ocean floor by means of a conductor pipe or surface casing 31 which is installed and preferably cemented in the ocean floor 13. Secured'to the support base 27 are two or

more guide columns

32 and 33 having

guide cables

34 and 35 extending vertically therefrom to the drilling barge 11 where they'are preferably secured to the barge by means of

constant tension winches

36 and 37. The

guide cables

34 and 35 are provided for the purpose of guiding pieces of equipment from the barge 11 into alignment on or in the casinghead 28 positioned on the ocean floor. In FIG- URE 1, a string of large-diameter pipe 45?, commonly known as a marine conductor pipe, is shown as being positioned on a wellhead at the ocean floor with the upper end of the marine conductor pipe 40 extending upwardly around the drill pipe 23 to a point above the surface of the water 12. Thus, during drilling operations, a drilling fluid may be circulated down the drill pipe 23 and up the annular space between the drill pipe 23 and the marine conductor pipe 46). The marine conductor pipe 40 is provided at its lower end by any suitable type of connector or coupling 41 for securing it to the top of a blowout preventer 42 which is in turn fixedly secured to a wellhead connector 43 which is removably secured on the casinghead 28, as shown in FIGURE 2.

A typical wellhead connector (FIGURES 1 and 2) may comprise an annular housing 44 whose inner diameter is just slightly greater than the outer diameter of the casinghead 28. The annular housing 44 is provided with an annular chamber 85 in which there is movably mounted an annular sleeve 46 having a tapered face or shoulder 47 on the inside thereof. The annular chamber is also provided with a plurality of locking blocks or dogs -48, each of which is provided with a vertical slot 51 which -is substantially wider than a pin 52 passing therethrough 'thus permitting movement of the dogs 48 so that they extend, in an operative position, into the bore of the hold- .down heador wellhead connector, as shown in the righthand half of FIGURE 2. In their operative position,

the dogs 48 normally extend into a recessed portion 53 of the annular sleeve 46, being forced to this position when the wellhead connector 43 was originally forced :down over the casinghead 28. By applying hydraulic pressure through pressure conduit 49, the annular sleeve '46 is forced downwardly so that its tapered shoulder 47 contacts the locking dogs 48 forcing them out of the re- .cess.53, from the position shown on the left-hand side of FIGURE 2 to the position in the right-hand side of FIGURE 2. At this time, the wellhead connector 43 is fixedly locked on the casinghead 28. At the same time, an annular sleeve 54 carried by the housing 44 forms a fluidtight seal between the wellhead connector 43 and the casinghead 28. To unlock the wellhead connector from the casinghead 28, fluid pressure would be applied to the connector throughpressure conduit 50. The pressure conduits 49 and wouldbe inthe form of flexible hoses extending up through the water to the drilling barge on the surface.

In FIGURE 2, the casinghead 28 is shown as being provided in the outer wall with recesses or a circumferential groove 55, preferably near the top thereof, to provide means for temporarily locking the wellhead connector 43 thereon. The casinghead 28 is also provided on the inner wall thereof with at least one landing surface or shoulder 56 from which a string of casing may be hung. In the casinghead arrangement shown in FIGURE 2 the landing surface 56 of the casinghead 28 is employed to seat a casing and tubing suspension body 58 thereon. It is quite apparent that the casing and tubing suspension body 58 forms a part of the casinghead 28 and may be .5 formed as an integral part of the casinghead, if desired. A string of casing 61 is normally secured to the lower end of the tubing and casing suspension body 58, as by welding.

The casing and tubing suspension portion 58 of the casinghead 23 has an inner wall that is irregular in that

annular grooves

64 and 65 are formed therein, as well as a splined section 66 and a seating shoulder 67. In order.

to protect the

grooves

64 and 65, splined section 66 and shoulder 67 during drilling operations, a temporary wear sleeve 6%; may have been installed in the casing suspension body 58at the time it was originally lowered into the casinghead 28. Alternatively the wear sleeve may be installed after the blowout preventer 42 (FIGURE 1) and wellhead connector 43 have been attached to the casinghead 28. The wear sleeve 68 protects the seating surfaces onthe inner wall of the casinghead or casing suspension body while the drill string is rotating therein. In some instances frictional contact'betweenya rotating drill string and the wear sleeve-68 might cause the wear sleeve to rotate and injure the shoulder 67 in whichitwas seated. To obviate this possibility, the wear sleeve '68 and the element in which it is seated are provided with cooperating anti-rotation elements carried on adjacent portions of the sleeve and the casing suspension body for engagement during the vertical seating of the i wear sleeve within the casinghead. One possible arrangewhether left-hand or right-hand threads are used.

' Prior to hanging another string of well casing or tubing in the casinghead or casing suspension body 58, the wear sleeve 68 can be removed by lowering a suitable running head, as shown in FIGURE 3, which has a pin 71 on the'outer surface thereof-to engage one or more J-slots 72 in the top of'the sleeve 68 in order to withdraw the sleeve from the well. It' is realized that the running string, which is essentially a long pipe string extending from the drilling vessel down to the wellhead, may be provided at its lower end with any other suitable type of connector means for latching onto the wear sleeve 68 and withdrawing it to the surface."

Another form of a wear sleeve is shown in another.

. arrangement ofa wellhead assembly in FIGURE 4 wherein a blowout preventer 42 and its associated wellhead connector 43 are illustrated as coupled to circumferential grooves 75 in the outer. Wall of the casing and tubing suspension body 58 rather than to the circumferential grooves 55 in the outer wall of the casinghead 28. This arrangement is possible since the casing suspension bo'dy'58 is fixedly secured within the bore of the casinghead 28 by means of hold-down slips 76. In addition to the well being provided with a conductor pipe 31 and a smaller string of casing'dl, another string of casing, say 9% inches in diameter, has been run into thewelldepending a from the casing hanger 78 which seats on landingshoulder 67. The casing hanger 78 may be of any suitable type but is preferably provided with hold-down slips 80 of the type 9 described in copending patent application Serial No. 48,-

646, filed August: 10, 1960. The upper end of the casing hanger 78 is provided with one or more upwardly extendthe wear sleeve 83.

ing anti-rotation lugs 81' or pins which are adapted to engage one or more lugs 82 carried on the lower end of It is understood that instead of employing pins 81 to contact lugs82 on the wear sleeve 33, the top of the casingv hanger 78 could have grooves. or

v notches extending downwardly from the upper end thereof to receive the lugs 82 carried by the wear sleeve.

The wear sleeve 83 has an internal diameter at least no greater than the vertical bore through the casing hanger 78 in order to protect the landing surface 84 of the casing hanger. At the same time the lower end of the wear sleeve 83 may seat on the landing surface 84, although preferably the wear sleeve 83 is seated with the outwardly extending lugs 82 seating on the top of the casing hanger 7 8. The wear sleeve 83 extends upwardly to the top of the casing and tubing suspension body 58 in order to protect the other landing surfaces or

shoulders

85, 86 and 87 formed on the inner wall of the casing suspension body member 58. In the event that the diameter of the wear sleeve 83 is substantially smaller than the through bore of the blowout preventer 42, a flange h!) may be secured outwardly on the top of the wear sleeve 83, as by welding, to center the top of the wear sleeve 83. This flange 94) also minimizes the amount of line solid matter that might settle down between the wear sleeve 83 and the casing suspension body 58. The entrance to the upper end of the wear sleeve 83 is preferably beveled, as at 931, in order to facilitate the running of tools therethrough. A series of radially-extending ports are provided through the wall of the wear sleeve 83 near the lower end thereof to permit the circulation of a flushing liuid out the ports and upwardly along the side of the wear sleeve 83 to flush out fine material which has settled between the wear sleeve 83 and the casing suspension body member 58 durnecessary in order to pull the wear sleeve out of the casinghead. In the event that flushing ports 92 are not provided, fluid may be flushed under the bottom of the wear sleeve and up along the outside thereof if the sleeve is not seated on the shoulder 84.

During drilling operations a wear sleeve would be employed at all times while drilling in order to protect the landing surfaces of the casinghead or the casing and tubing suspension body as described hereinabove. A new wear sleeve would be inserted into the well head after every string of casing was set therein, provided that additional drilling was to take place. Any suitable well known type of straddle packer 93 (FIGURE 6) may be run into the well, prior to removing the sleeve therefrom, on a wash pipe 94 which would extend to the surface. The two packer elements would be positioned so as to straddle the flushing ports and/ or the bottom of the wear sleeve 83 so that fiuid being pumped down the wash string 94 and out between the straddle packer 93 would be forced up the outside of the wear sleeve 33 to flush material therefrom. a

We claim as our invention:

1. A drilling wellhead comprisinga large-diameter well casing, a casinghead having a vertical bore therethrough and being secured to the upper end of said large-diameter well casing, casing landing shoulder means formed on the inside wall of said casinghead, the'vertical bore through said easinghead being unobstructed vertically above shoulder means, seating means formed on the inner wall of said casinghead, a tubular wear sleeve removably positioned within the casinghead bore, said wear sleeve being f a vertical length suflicient to be positioned adjacent the shoulder means of said casinghead when the sleeve is in its seated position on said seating means, and cooperating anti-rotation means carried by adjacent portions of said wear sleeve and said casinghead for engagement when the wear sleeve is seated in the casinghead, said anti-rotation means carried by said wear sleeve being fixedly secured thereto and withdrawable therewith on axial movement of said wear sleeve out of said casinghead.

2. A drilling wellhead comprising a large-diameter well casing, a casinghead having a vertical bore therethrough and being secured to the upper end of said large-diameter well casing, casing landing shoulder means formed on the inside wall of said casinghead, the vertical bore through said casinghead being unobstructed vertically above shoulder means, seating means formed on the inner wall of said casinghead, a tubular wear sleeve removably positioned within the casinghead bore, said wear sleeve being of a vertical length sufficient to be positioned adjacent the shoulder means of said casinghead when the sleeve is in its seated position on said seating means, cooperating antirotation means carried by adjacent portions of said wear sleeve and said casinghead for engagement on seating said wear sleeve within said casinghead, said anti-rotation means comprising at least one stop member mounted on a portion of said casinghead projects above said support base, casing landing shoulder means formed on the inside wall of said casinghead, the vertical bore through said casinghead being unobstructed vertically above shoulder means, seating means formed on the inner wall of said casinghead, a tubular wear sleeve removably positioned within the casinghead here, said wear sleeve having an internal diameter substantially equal to the bore of said casinghead, said wear sleeve being of a vertical length sufficient to be positioned adjacent the shoulder means of said casinghead when the sleeve is in its seated position on said seating means, cooperating anti-rotation means carried by adjacent 'portionsof said Wear sleeve and said casing'head for engagement on seating said wear sleeve within said casinghead, said anti-rotation means comprising at least one stop member mounted on the outer wall of said wear sleeve, and at least one cooperating stop member carried within the bore of said casinghead.

4. An underwater drilling wellhead comprising a largediameter well casing, a well head support base positioned below the surface of a body of water and having a vertical hole therethrough, a casinghead having a vertical bore therethrough and being secured to the upper end of said large-diameter well casing and extending through the hole in said support base in a manner such that at least a portion of said casinghead projects above said support base, a plurality of easing landing shoulder means formed on the inside wall of said casing head at axially displaced points therealong, seating means formed on the inner wall of said casinghead, the vertical bore through said casinghead being unobstructed vertically above shoulder means, a tubular wear sleeve removably positioned within the casinghead bore, said wear sleeve havhig an internal diameter substantially equal to the bore of said casinghead, said wear sleeve being of a vertical length suilicient to be positioned adjacent the shoulder means of said casinghead when the sleeve is in its seated position on said seating means, cooperating anti-rotation means carried by adjacent portions of said wear sleeve and said casinghead for engagement on verticallyseating said wear sleeve within said casinghead, said anti-rotation means. comprising at least one stop member mounted on the outer wall of said wear sleeve and at least one cooperating stop member carried within the bore of said casinghead, and fluid port means through the wall of said wear sleeve near the lower end thereof for discharging a flushing fluid therethrough.

5. An underwater drilling wellhead comprising a largediameter well casing, a wellhead support base positioned below the surface of a body of water and having a vertical hole therethrough, a casinghead having a vertical bore therethrough and being secured to the upper end of said large-diameter well casing and extending through the hole in said support base in a manner such that at least a portion of said casinghead projects above said support base, a plurality of easing landing shoulder means formed points therealong, the vertical bore through said casinghead being unobstructed vertically above shoulder means, a blowout preventer Iemovably secured to the top of the casinghead and having a vertical bore therethrough, seating means formed on the inner-wall of said casinghead, a tubular wear sleeve removably positioned within the casingh ead bore, said wear sleeve having an internal diameter substantially equal to the bore ofsaid casinghead and having an outer diameter of a size to pass through said blowout preventer, said wear sleeve being of a vertical length sufiicient to be positioned adjacent the shoulder means of said casinghead when the sleeve is in its seated position on said seating means, cooperating anti-rotation means carried by adjacent portions of said wear sleeve and said casinghead for engagement on vertically seating said wear sleeve within said casinghead, said anti-rotation means comprisingtat least one stop member mounted on the outer wall of said wear sleeve, and at least one cooperating stop member carried within the bore of said casinghead, the upper end of said wear sleeve flaring outwardly to a diameter substantially equal to the bore of the casinghead and the blowout preventer secured thereto, and fluid port means through the wall of said wear sleeve near the lower end thereof for discharging a flushing fluid therethrough.

6. In avmethod of drilling an underwater well wherein a casinghead has been anchored to the ocean floor and a string of casing hung .from the casinghead, said method comprising covering exposed landing surfacesin said casinghead with a wear sleeve to prevent frictional contact with a drill stem, anchoring the wear sleeve against rotational movement within the casinghead, lowering a drill bit and a drill stem through said wear sleeve and casinghead, drilling the well while rotating thesdrill stem and circulating a drilling fluid down the drill stem and up the outside thereof between the drill stem and the wear sleeve, subsequently pulling the drill stem from the well,trunning a pipe string down to the wear sleeve, connecting the pipe string to the wear sleeve, and withdrawing the sleeve from the casinghead.

7. In a method of drilling an underwater well wherein a casinghead has been anchored to the ocean floor and a string of casing hung from the casinghead, said method comprising coveriru exposed landing surfaces in said casinghead with a wear sleeve to prevent frictional contact with a drill stem, anchoring the wear sleeve against rotational movement within said casinghead, lowering a drill bit and a drillstem through said Wear sleeve and casinghead, drilling the well while rotating the drill stem and circulating a drilling fluid down the drill stem and up the outside thereof, subsequently pulling the drill stem from the well, lowering a wash pipe string havinga straddle packer thereon to a position so that the upper portion of the packer is below the top of the wear sleeve and the lower portion of the packer is below flushing ports near the bottom of the sleeve, circulating flushing fluid down the wash pipe string and up the outside of the wear sleeve to remove fine solid matter therefrom, withdrawing the wash pipe string, running a pipe string down to the wear sleeve, connecting the pipe string to the wear sleeve,'and withdrawing the sleeve from the casinghead.

References Cited by the Examiner.

UNITED STATES PATENTS CHARLES E. OCONNELL, Primary Examiner.

Claims

1. A DRILLING WELLHEAD COMPRISING A LARGE-DIAMETER WELL CASING, A CASINGHEAD HAVING A VERTICAL BORE THERETHROUGH AND BEING SECURED TO THE UPPER END OF SAID LARGE-DIAMETER WELL CASING, CASING LANDING SHOULDER MEANS FORMED ON THE INSIDE WALL OF SAID CASINGHEAD, THE VERTICAL BORE THROUGH SAID CASINGHEAD BEING UNOBSTRUCTED VERTICALLY ABOVE SHOULDER MEANS, SEATING MEANS FORMED ON THE INNER WALL OF SAID CASINGHEAD, A TUBULAR WEAR SLEEVE REMOVABLY POSITIONED WITHIN THE CASINGHEAD BORE, SAID WEAR SLEEVE BEING OF A VERTICAL LENGTH SUFFICIENT TO BE POSITIONED ADJACENT THE SHOULDER MEANS OF SAID CASINGHEAD WHEN THE SLEEVE IS IN ITS SEATED POSITION ON SAID SEATING MEANS, AND COOPERATING ANTI-ROTATION MEANS CARRIED BY ADJACENT PORTIONS OF SAID WEAR SLEEVE AND SAID CASINGHEAD FOR ENGAGEMENT WHEN THE WEAR SLEEVE IS SEATED IN THE CASINGHEAD, SAID ANTI-ROTATION MEANS CARRIED BY SAID WEAR SLEEVE BEING FIXEDLY SECURED THERETO AND WITHDRAWABLE THEREWITH ON AXIAL MOVEMENT OF SAID WEAR SLEEVE OUT OF SAID CASINGHEAD.