US 3147992 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Sept. 8, 1964 J. A. HAEBER ETAL 3,147,992
WELLHEAD CONNECTOR Filed April 27, 1961 e Sheets-Sheet 1 FIG. 1
INVENTORSI J. A. HAEBER R. F. PERNER THEIR AGENT p 1964 J. A. HAEBER ETAL 3,147,992
WELLHEAD CONNECTOR Filed April 27, 1961 6 Sheets-Sheet 2 96 INVENTORSI J. A. HAEBER R. F. PERNER a flm THEIR AGENT P 8, 1964 J. A. HAEBER ETAL 3,147,992
WELLHEAD CONNECTOR Filed April 27, 1961 6 Sheets-Sheet 5 J. A. HAEBER R. F. PERNER BY? 5/ maaat HEIR AGENT P 8, 1 64 J. A. HAEBER ETAL WELLHEAD CONNECTOR 6 Sheets-Sheet 5 Filed April 27, 1961 INV ENTORSI J. A. HAEBER R. F. PERNER BY; ifi wcwut EIR AGENT United States Patent 3,147,992 WELLHEAD CONNECTOR John A. Haeher, Houston, Tex., and Raymond F. Perner, Metairie, 1.21., assignors to Shell Oil Company, New York, N.Y., a corporation of Delaware Filed Apr. 27, 1961, Ser. No. 105,980 Claims. (Cl. 285-18) This invention relates to apparatus for use on offshore wells and pertains more particularly to a wellhead apparatus adapted to be securely locked on a well casinghead positioned under water. The present invention is especially concerned with apparatus for connecting a wellhead component, such for example as a blowout preventer, to a vertically extending wellhead component in a securely locked and fluidtight manner so that the wellhead component could not he accidentally separated from the vertically extending well member.
In an attempt to locate new oil fields an increasing amount of Well drilling has been conducted at offshore locations, such for example, as off the coast of 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 the conventional manner that is used on land wells, with a conventional wellhead assembly being attached to the top of the casing. Attempts have been recently 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 under water at a depth suflicient 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 than the shallow depth at which a diver can easily operate, it has been necessary 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 casinghead may have attached thereto various pieces of equipment by means of the apparatus of the present invention.
It is, therefore, a primary object of the present invention to provide apparatus for connecting a wellhead component to an underwater wellhead assembly while operating the apparatus from a remote location.
It is another object of the present invention to provide a wellhead such as a blowout preventer with a connector device so that the blowout preventer may be lowered on guidelines and seated on an underwater well casinghead and securely locked thereto in a fluid-tight manner with the sealing and locking operations being carried out from a remote location. A further object of the present invention is to provide a remotely operable connector apparatus adapted to lock on to an underwater wellhead and pack off the annulus between the connector device and the wellhead.
Another object of the present invention is to provide a remotely-controlled hydraulically-operated connector device and sealing apparatus for holding a wellhead component on a wellhead against pressures which might be encountered therein at any time, even in the event that the hydraulic pressure lines to said apparatus should break, or otherwise become inoperative.
A still further object of the present invention is to provide a wellhead connector device and sealing apparatus which may readily be unlocked from an underwater wellhead and withdrawn to an operational base at the surface, such for example, to a drilling barge or platform.
Another object of the present invention is to provide a wellhead connector device adapted to seat on an underwater wellhead and be connected to the outside thereof, rather than the inside thereof, so that a well casinghead may be employed which is of a size slightly larger than the largest diameter drill bit which is to be run through the conductor casing.
These and other objects of this invention will be understood from the following description taken with reference to the drawing, wherein:
FIGURE 1 is a diagrammatic view illustrating a floatable drilling barge positioned on the surface of the ocean from which a blowout preventer together with the connector device of the present invention is being lowered to the top of a well casinghead positioned on the ocean floor;
FIGURES 2 and 2A are views taken in longitudinal cross-section of one form of a wellhead connector illustrated as being positioned on a vertically-extending well member, the connector in FIGURE 2 being shown in unlatched and unsealed position while the connector in FIGURE 2A is shown in sealed and latched position;
FIGURE 3 is a plan view taken in horizontal crosssectiori along line 3 of FIGURE 2 when turned on a vertical axis;
FIGURE 4 is a view in longitudinal cross-section of another form of a wellhead connector shown in its inoperative position on a Wellhead;
FIGURE 5 is a partial view taken in longitudinal crosssection of the Wellhead connector of FIGURE 4 in its sealed position on a wellhead member;
FIGURE 6 is a plan view taken in horizontal crosssection along the line 66 of FIGURE 4;
FIGURE 7 is a plan view taken in horizontal crosssection illustrating another form of latching dogs for a connector device;
FIGURE 8 is a view taken in longitudinal cross-section of a portion of a wellhead connector illustrating latching means of another type;
FIGURE 9 is a view taken in partial longitudinal crosssection of a fragment of a wellhead connector illustrating a sealing member being pressed against a smooth-walled P P FIGURE 10 is a view taken in longitudinal cross-section illustrating another form of a wellhead connector shown as latched and sealed on the outer wall of a smooth-walled well member;
FIGURE 11 is a view taken in longitudinal cross-section of another form of a wellhead connector in its unsealed and unlatched position; and,
FIGURE 12 is a view taken in longitudinal cross-section of the wellhead connector of FIGURE 11 shown in its sealed and latched position.
, Referring to FIGURE 1 of the drawing, a drilling barge 11, of any suitable floatable type is illustrated as floating on the surface of the water 12 and fixedly positioned over a preselected drilling location by being anchored to the ocean floor 13 by suitable anchors (not shown). Equipment of this type may be used when carrying on well drilling operations in water depths varying from about to 1500 feet or more. The drilling barge is equipped with a suitable derrick 16 and a rotary table 17 as well as other auxiliary equipment needed during the drilling of a Well. The derrick 16 is positioned over a drilling slot or well 18 which extends vertically through the barge in a conventional manner. When using the equipment of the present invention the slot 18 and the barge 11 may be either centrally located or extend in from one edge. However, drilling operations may be carried out over the side of the barge without the use of a slot. Additionally, it is to be understood that the equipment of the present invention may also be used while drilling a well from any suitable operational base positioned above the surface of a body of water, such for example, as from a drilling barge having feet extending to the ocean floor, or from a platform permanently positioned on the ocean floor.
A typical underwater wellhead structure is illustrated in FIGURE 1 as comprising a base member 21 which is positioned on the ocean floor 13 and is fixedly secured to a conductor pipe or large-diameter well casing 22 which extends down into a well, which has been previously drilled, and is cemented therein. Thus, the base structure 21 is rigidly secured to the ocean floor in order to support two or more vertically-extending guide columns 23 and 24 adapted to receive and guide therein guide arms 25 and 26 which are arranged to slide along vertically extending guide cables 27 and 28. The lower ends of the guide cables 27 and 28 are anchored to the base structure 21 within the guide columns 23 and 24 while extending upwardly through the water to the drilling barge 11 where they are preferably secured to constant tension hoists 31 and 32.
Centrally positioned above the base plate 22 and fixedly secured thereto, or to the conductor pipe 22, is a well oasinghead 33 which may be provided with a sealing groove 34 cut in the outer wall thereof or on the periphery. The casinghead is also provided with a latching shoulder 35, which may also be in the form of a groove, and extends around the casinghead. The wellhead is also shown as being provided with a cement circulation or kill line 36 which is connected preferably by means of a quick-disconnect coupling 37 to a flowcontrol valve 38.
The guide arms 25 and 26 are illustrated as being connected to a blowout preventer 40 which is rigidly flanged to a wellhead connector 41 of the present invention. In FIGURE 1 the wellhead connector 41 is shown as it is being lowered onto the top of the casinghead 33. The combined blowout preventer and wellhead connector 40 and 41, respectively, are run into position on the top of the well by being lowered through the water from the barge 11 by means of a pipe string 42, commonly known as a running string, the blowout preventer 40 being connected to the lower end of the running string 42 by means of a suitable coupling or connector 43 which may take the form of the wellhead connector 41. The valve 38, connector 41, blowout preventer 40 and connector 43 are all hydraulically operated and are provided with hydraulic flowlines 44 and 45, 46 and 47, 48 and 49, and 50 and 51, respectively. These flowlines 44 through 51 extend upwardly from the wellhead equipment to the barge 11 where they are connected to a suitable source of pressure fluid.
Referring to FIGURE 2 of the drawing, the wellhead connector 41 of FIGURE 1 is shown as comprising a body member having upper and lower portions 54 and 55, respectively, which are connected together in any suitable manner, as by bolts 56. The upper end of the upper portion 54 of the body member may be closed by a cap member 57 which may be screw-threaded to the body member 54, as at 58. The lower end of the lower portion 55 of the body member may be closed by a plate 60 which is connected thereto by bolts 61. Preferably, the lower plate 60 of the body member is provided with an outwardly flaring skirt 62 which surrounds the bore or throughbore 63 extending u wardly through the body member 54-55. The cap 57 has a bore or throughbore 64 of reduced diameter thus forming a seating shoulder 65 which is adapted to seat on a landing surface 66 formed on the outside of a vertically-extending well member 67, preferably at the upper end thereof, as illustrated.
The well member 67 is provided with a bore 68 therethrough which may vary in diameter at one or more places to form one or more seating shoulders 71, 72 and 73 on which various well equipment may be seated or 4. latched. Formed on the outer surface of the vertically extending well member 67 is a shoulder 74 which may take the form of a groove similar to that forming shoulder 72 on the inner wall of the well member 67. The latching shoulder 74 formed on the well member 67 is positioned down from the top of the well member 67 a distance equal to the distance that a plurality of latching dogs 75, carried by the body member 54-55, are positioned from the seating shoulder 65 and the cap 57 of the body member.
The shoulder-engaging latching dogs 75 carried by the body member are arranged for substantially lateral movement into and out of engagement with the latching shoulder '74 of the well member 67. The latching dogs 75 are actuated in any suitable manner. Preferably, a fail-safe type of latching dog 75 is employed. In one such arrangement, a compression spring 76 is mounted in back of each latching dog 75 for urging it inwardly toward the axis of the body member 67. A piston 77 is formed on the end of the latching dog 75 with a fluid conduit 78 extending through the wall of the body member portion 55, from the outside thereof, so that a pressure fluid may be applied to one side of the piston 77 to retract the latching dog 75 back into the body member against the action of the compression spring 76. It will be seen that, upon the failure of pressure fluid to the conduit 78, the spring 76 would maintain a force on the latching dog 75 urging or maintaining the latching or locking dog in a locked position in engagement with the shoulder 74, thus preventing relative axial separation of the body member 54-55 from the well member 67.
Prior or subsequent to the actuation of the latching dogs 75, the body member 5455 is sealed to the outer wall of the well member 67 in a fiuidtight manner by any suitable annular packing element 80. The packing element 80 may be reinforced by metal rib sections 81, if desired. Formed within the body member 5455 is a chamber 82 in which a piston 83 is slidably mounted for limited vertical movement. The upper end of the piston 83 may be beveled outwardly, as at 84, so as to facilitate movement of the piston within the chamber 82 of the outside of the annular seal 80, thus supplying an increasing amount of pressure on the seal 80 as the piston moves upwardly. If desired, the outer surface of the well member 67 may be provided with a peripheral groove 85 near the top thereof for receiving a portion of the packing element 80 therein. However, the packing element 80 may also be employed to seal against a smooth-surfaced outer wall of a well member 67, as illustrated in FIGURE 9 of the drawing. The vertical width of the shallow groove 85 in the outer wall of the well member 67 is sufiicient to receive at least a portion of the packing element 80 therein without permitting the reinforcing rib sections 81 of the packing element 80 from entering the groove 85, as illustrated. The piston 83 is energized by applying a pressure fluid through a pressure conduit 86 in communication with one side of the piston 83 with fluid above the piston being allowed to discharge through a second conduit 87 in communication with the space 88 above the piston.
In order to insure that a positive seal is maintained by the packing element 80 around the well member 67 at all times, suitable positioning means or locking means are provided for maintaining a piston 83 in its raised position, as shown on the right-hand side of FIGURE 2. In the wellhead connector shown in FIGURES 2 and 3 a rotatable ring 90 is provided in the lower portion of the body member 55 at a point opposite a portion of the piston 83. The rotatable ring 90 is provided with inwardly extending breach-type locking elements or threads 91 while cooperating breach-type locking elements or threads 92 extend outwardly and are formed on the outer surface of the piston 83. When the piston is being raised and lowered, the locking thread surface 92 on the piston 83 is positioned adjacent a smooth surface segment of the rotating ring 90, as shown in the lefthand half of FIGURE 2 when the piston 83 is in its unlocked position. After the piston 83 has been raised to its operative position, as shown in the right-hand half of FIGURE 2, the ring 90 is rotated so that the locking elements thereon engage the locking elements on the piston 83 so as to maintain the piston 83 in a raised position at all times. Thus, in the event of pres sure fluid loss to conduit 86, an effective seal would be maintained above the well member 67 as the piston 83 would be maintained in its upper position against the packing element 80.
T actuate the rotatable locking ring Within the wellhead connec tor device 41 of FIGURE 2, the lower portion of the body member 55 is provided with at least one and preferably two condh'its- 9 3 and 94 which extend horizontally through the body member At substantially the midpoint of the conduits, actuating arms.95 and 96 substantially block passage through the conduits. The arms 95 and 96 are rigidly secured to the rotatable rin g "90- which is adapted to be rotated in a horizontal plane when pressure is exerted on the arms 95 and 96 in one direction or the other. A flexible piston is provided Within the conduits 93 and 94 on either side of the actuating arms 95 and 96. Each flexible piston takes the form of a series of ball bearings or spheres 97 in contact at one end with the actuating arm 95 while a short sealing piston 98 closes the other end of the conduit in a fiuidtight manner. Thus, a fluid pressure being supplied to .One end of the conduit 93 will force the piston 98, spheres 97 and actuating arm98 together with rotatable ring 90 in one direction so that the locking surfaces 91 thereon will engage the locking surfaces 92 on the sidewalls of the piston 83. Pressure applied to the other end of the conduit 93 will operate in the opposite manner to InOVe the rotatable ring 90 inthe opposite direction until the looking elements become disengaged from the locking elements 92 on the piston. At this time the piston 83 may be again moved up or down.
Another arrangement of the wellhead connector of the present invention is shown in FIGURE 4 wherein the lower portion 55 of the body member is provided with an annular chamber 100 in which a series of jack screws 101 extend and each is provided with a gear or sprocket wheel 102. A drive motor 103, preferably of the hydraulically-actuated type, is positioned in the lower chamber 100 with its shaft 104 extending outwardly through the housing of the body member 55. On rotation of the drive shaft 104 a driving gear or sprocket 105 on the motor 103 is rotated to move a drive chain 106 (FIG- URE 6) which interconnects the drive gear 105 on the motor with the various sprocket wheels 102 of the jack screws 101. A series of idler gears 107 may be employed if desired or necessary. The upper ends of the jack screws 101 (FIGURE 4) are in contact with the lower surface of the piston 83 and are employed to force a piston upwardly against the sealing element 80 to force it in sealing engagement with the well member 67 as shown in FIGURE 5. Alternatively, a pressure fluid may be supplied through conduit 86 to force the piston 83 upwardly and extend the sealing member 80 into fiuidtight engagement with the well members 67, after which the drive motor 103 may be actuated to rotate the jack screws 101 until they have been raised into contact with the bottom of the piston 83 again so as to hold it in its sealed position. It may be seen that upon failure of pressure fluid to the piston through conduit 86, the piston 83 would be held in its raised position by the jack screws 101.
In FIGURES 7a and 8a another form of a latching dog is illustrated wherein the body member 55a of the Well head connector is provided with a pair of conduits 78a and 79a extending through the wall thereof from the outside into communication with opposite ends of the chamber in which the piston 77a is slidably movable. Thus, by applying pressure to conduit 79a the piston and its connected latching dog 750 will be forced inwardly into latching contact with the shoulder 74a on the well member 67a. If desired, a spring 7611 may also be employed but is not necessary. For unlatching the dog 75a, pressure fluid would be applied through conduit 78a.
Another form of a wellhead connector is illustrated in FIGURE 10 wherein a body member 110 is provided with a stabbing skirt 111 at the lower end thereof which facilitates centering the wellhead connector onto the top of a well member 67 which is provided with a shoulder 112 on the outer surface thereof for receiving a locking cam 113 therein. The locking dog or cam 113 is pivotally mounted within the body member and actuated by piston means 114 carried thereby. The body member 110 is provided with pressure fluid conduits 115, 116 and 117 which interconnect so that a pressure fluid may be applied simultaneously to the actuating piston 114 of the cam 113 and to an inflatable packer or sealing element 118 carried by the body member for sealing off between the adjacent walls of the body member and the well niember. Additionally, the body member may be provided with asolid O-ring seal 120.
Another form of a wellhead connector is illustrated in FIGURES 11 and 12 wherein thewellhead connector comprises a body member 123 having a vertically-disposed and inwardly-expansible sealing element 124 carried in a chamber 125 therein. An upwardly-extending retaining element 126 and a downwardly-depending retaining element .127 anchor the ends of the sealing element to the body member 123 while permitting the center portion of the sealing element 124 to expand against a well member 67, as shown in FIGURE 12. The body member 123 is provided in the lower portion thereof with a plurality of locking dogs, each of the dOgs 127 having an actuating piston 128 slidably movable within a piston chamber 129 which is supplied with a pressure fluid through conduit 130. The conduit 130, and a conduit 131 extending through the wall of the body member 123 opposite the sealing element 124, are interconnected and served by a common pressure fluid conduit 132. If desired, the upper edge of the locking dogs 127 may be tapered as shown in FIGURE 12 in order to facilitate retraction of the dog when pressure has been released from the locking dog 127 and sealing element 124 and the body element 123 withdrawn from engagement with the well member 67.
In employing the wellhead connector 41 (FIGURE 1) of the present invention, the wellhead connector 41 is rigidly secured coaxially with a suitable wellhead component, such for example, as a blowout preventer 40. The combination of the blowout preventer 40 and its wellhead connector 41 may be lowered from a barge 11 into contact with a well casing head 33 located underwater. Since the blowout preventer 40 and the wellhead connector 41 are fixedly secured together, it is necessary that only one of the components, in this case, the blowout preventer, be provided with guide arms 25 and 26. However, in the event that it is desired to run a wellhead connector alone down through a body of water to contact a Wellhead component it is necessary that the wellhead connector 43 be provided with a pair of guide arms 25a and 26a.
In FIGURE 1 a wellhead connector 43, which may be similar in construction to the wellhead connector 41 described hereinabove, is seated on and locked and sealed to a vertically extending tubular component 30 which may be similar in shape and construction to the casinghead 33. Thus, prior to running the blowout preventer 40 and its wellhead connector 41 to its underwater location on the casinghead 33, the smaller wellhead connector 43 carried at the lower end of the pipe string 42 is set upon and latched to the vertically extending tubular member 30 on the top of the blowout preventer 40 by applying hydraulic pressure through conduit 50. The entire equipment assembly would then be lowered from the barge 11 to the casinghead 33 by means of the pipe string 42. When the blowout preventer 41 is seated within the casinghead 33, fluid pressure would be applied from the barge 11 at the surface to actuate the wellhead connector in a manner described hereinabove.
We claim as our invention:
1. A wellhead connector assembly comprising (a) a body member having a passage extending axially therethrough, said body member being positionable and connectible in axially telescopic relation with a longitudinally projecting well member having an axial passage therethrough forming an unimpeded throughbore passing through said body member and said well member, said well member being of a size to fit within the passage of said body member,
(11) cooperating connector means carried in the adjacent walls of said body member and said Well memher,
() one portion shoulder means formed by outer wall of said well member,
(d) the other portion of said connec or mrfiis comprising shoulder-engagingjo g means carried by said body mgiber the adjacent Wall thereof in a position for registering with said shoulder means, said locking means being substantially laterally movable into and out of engaging relation with said shoulder means,
(2) actuating means carried by said body member and being operatively connected to said locking means when urging said locking means to a locked position in engagement with said shoulder means whereby said engaged locking means prevents relative axial separation of said body member and said Well member,
(f) said body member having conduit means through the wall thereof through which pressure fluid is communicable to said actuating means,
of said connector means comprising a recessed area in the (g) annular sealing means carried by said body member and axially displaced from said locking means for sealing off between the adjacent walls of said body member and said well member, and
(h) weight supporting substantially circumferential shoulder means formed on the wall of said body member within the passage thereof for seating on the upper end of said well member when in engagement therewith.
2. The apparatus of claim 1 wherein said body member has a circumferential recessed portion in the inner wall thereof, said annular sealing means being carried in said recessed portion. h/
3. The apparatus of claim 2 wherein t e inside diameter of said annular sealing m us is normally no greater than the diameter of the throughbore of said body member.
4. The apparatusKlaim 2 wherein said annular sealing means are extendible radially inwardly to seal against said well member and said body member is provided with second conduit means through the wall thereof which is communicable with a source of pressure fluid.
5. The apparatus of claim 2 including second actuating means in operative engagement with said annular sealing means for moving said annular sealing means radially inwardly to seal against said well member upon actuation of said second actuating means.
References Cited in the file of this patent