Pulling head for removably engaging a conduit end

A pulling head adapted to removably engage the end fitting of a conduit to facilitate the latter being pulled with a substantial tensional force. The head includes an engaging ring at one end thereof which is removably operable to register about and firmly engage the cable end fitting. A wire line extending from the pulling head nose end is attachable to a winch or other mechanism capable of applying the necessary pulling force thereto.

BACKGROUND OF THE INVENTION 
In the normal practice of pulling cables or other flexible conduits, a 
considerable force must be initially applied to the cable to draw it from 
its reel or other holding mechanism. When the conduit is being drawn 
through a relatively spacious receptacle or even through an environment 
where it is unconfined, the pulling head utilized for applying the 
necessary pulling tension has virtually no limitations as to size. When, 
however, the conduit is to be pulled through aconfined conduit guide or 
other member, said member must be sufficiently large to permit the conduit 
as well as its pulling mechanism to pass therethrough. 
Where the conduit guide is of relatively small diameter, the pulling head 
must likewise be sufficiently small to advance along the guide. Further it 
must advance without becoming entangled, jammed, or otherwise subjected to 
conditions that would cause the guide to be damaged. 
In the instance of offshorre or subsea operations related to production of 
hydrocarbon liquids or gas, such flexible conduits are normally utilized 
in several capacities. Primarily they can be utilized for carrying a 
liquid or gas between an offshore location such as a drilling platform, to 
the shore. Alternately, the conduits may comprise conductors or electrical 
circuitry for communicating a remote well head to the control center 
located on the marine platform. 
Normally in the instance of any offshore platform which is adapted to cover 
an expansive subterranean field or reservoir, the platform will be 
communicated to a number of remote well heads by way of conduits and 
electrical cables in the manner above stated. A primary feature which 
urges utilization of flexible type conduits is that they are more readily 
handled and can be installed without concern for their rigidity. Thus, 
they can be bent and adjusted to some extent to facilitate their being 
laid onto the ocean floor. 
In the instance of many offshore or marine platforms, the structure is 
originally designed in contemplation of drilling a predetermined number of 
wells into a subterranean hydrocarbon containing reservoir. Thus, the 
platform is originally designed with a fixed number of conductors which 
are so positioned that each can readily accommodate a descending drill 
string. Therefore a well can be subsequently completed into a working unit 
through each conductor. 
A platform of this nature is fixed and stable once it is piled into the 
ocean floor. It can however, be subsequently adapted to accommodate 
additional remotely located wells. This is achieved most readily by the 
provision of flexible conduits that extend from the platform, to the 
various well heads. The latter can then be operated from the platform, and 
further the product drawn from the well can be conducted to the platform 
processing equipment. 
In such an instance, when it is desired to install additional conduits onto 
a platform for the above noted purpose, the conduits, wound on reels, are 
usually positioned on the platform. Thereafter, they are drawn by a 
pulling mechanism downwardly through one of the drilling conductors and 
out to the sea bed for connection to a conventional flowline. 
The conduit installation operation can be achieved in a number of ways. 
However, in each instance it is necessary to firmly grasp the end of the 
flexible conduit, and exert enough axial pull that it can be unwound from 
its reel. It is thereafter pulled with a sufficient force that it will be 
positioned as desired on the ocean floor. 
What is presently disclosed as a pulling head for removably engaging the 
end fitting of a flexible conduit or cable so that the latter can be 
forcefully drawn from a reel or the like. The head is adapted to engage 
the formed end of a cable fitting thereby establishing a sufficiently firm 
grip on the conduit that the needed pulling force can be appied thereto. 
What is further provided is a pulling head of the type described which is 
of a diameter that it does not substantially exceed the diameter of the 
conduit being pulled. Thus, the flexible conduit can be drawn through a 
minimal sized guide or drilling conductor without concern that the pulling 
head will cause damage to the guide passage or to other members which it 
contacts during the pulling step. 
It is therefore an object of the invention to provide a pulling head for a 
flexible conduit or similar cable type element, which pulling head is 
readily removable from the conduit end fitting. A further object is to 
provide a pulling head of the type contemplated which is capable of 
exerting an axial force to a conduit while drawing the latter through a 
limited size guide passage. 
In achieving these objectives, the presently disclosed conduit pulling head 
is provided. The latter includes primarily a multi-segment ring or collar 
member that is adapted to be positioned on, and firmly grasp the end 
fitting of a conduit to be pulled. A nose piece detachably engages the 
ring and includes a wire line or similar member which can be of any 
desired length such that it can be connected to a pulling element such as 
a winch, a motor or the like.

Referring to FIG. 1 of the drawings, conduit or cable 10 which is to be 
unwound from a reel or other holding mechanism is here shown. It can be 
characterized as previously noted, by an internal structure which would 
permit carrying of a produced product therethrough or merely enclosing a 
number of control elements such as electrical, pneumatic or hydraulic 
lines. The lines are protected by a heavy, flexible outer sheath or 
jacket. 
To facilitate pulling a conduit 10 to achieve its unreeling and positioning 
at a desired location, the conduit end is provided with a hub 11 which 
firmly engages, and is fixed thereto. When the conduit is finally in 
position, hub 11 is sealably joined with a corresponding hub by an 
external clamp or the like. 
An end fitting 11 of this type is typified by a Grayloc Hub which is 
capable of being firmly fastened to the end of a conduit. Said hub is 
comprised primarily of a cylindrical body having an outer diameter which 
is substantially smaller than the outer diameter of conduit 10. Further, 
hub 11 is provided with a rim 12, and with a recessed face 15 that 
receives a deformable metallic seal ring 21. The latter can be compressed 
as will be herein described, by a corresponding hub to define an annular 
water tight joint thereby protecting the conduit interior from exposure to 
water. 
In the embodiment shown, the hub 11 is characterized by annular rim 12 
disposed outwardly of the hub body, and having a sloping pressure surface 
14. The latter is at a sufficient angle to allow the application of 
maximum axial pulling force thereto, and yet minimize the diameter of the 
hub. 
Pulling head 13 which is adapted to removably engage hub 11 includes a 
first clamping ring section which is comprised of a plurality of discrete 
ring segments 16 and 17. This section can be comprised of two or more 
elements, all of which when properly assembled define a unitary body 
having an internal axial passage 18 with an inner, tapered contact portion 
20. 
Individual ring segments 16 and 17 as shown in FIG. 2, are arcuate, or 
semi-circular when two are utilized. When assembled together the 
respective segments define an elongated sleeve or cylindrical body. Said 
unit is characterized by an outer diameter which is equal to or 
substantially equivalent to the diameter of conduit 10. It further 
includes a peripheral bearing shoulder 42 on the wall of axial passage 18. 
To facilitate assembly of segments 16 and 17 into their clamping mode, said 
members can include one or more alignment pins or screws 19. The latter 
are positioned to register within a corresponding hole in the adjacent 
ring segment. Alternately, said pins can be replaced by a transverse 
fastening stud or bolt 22. 
A plurality of such fastening bolts or studs 22 extend transversely of the 
assembled ring segments to maintain the latter firmly in gripping 
position. A locking nut 23 is carried on each stud or locking bolt 22. 
Each ring segment is provided with one or more recesses 24 which allow nut 
23 to be lodged within the outer periphery of the assembled clamping ring 
section. 
The leading end of pulling head 13 is provided with a nose piece 26 
comprised of a generally hemispheric shaped member which is formed of 
steel or a similar, durable metal. The forward face 27 of nose piece 26 is 
preferably provided with a smooth contoured surface to facilitate its 
sliding movement through a guide or similar member as will be hereinafter 
noted. 
The rear surface 28 of nose piece 26 is disposed in abutting engagement 
with seal ring 21. A plurality of clamping bolts 29 maintain nose piece 26 
and the clamping ring section in axial alignment with seal ring 21 
compressed against hub 11 face to thereby form a water tight enclosure at 
the end of conduit 10. 
Nose piece 26 is provided with an axial cavity formed in rear face 28 and 
extending therethrough in progressively decreasing cylindrical sections. 
The inner cylindrical section 25 defines a forward chamber 31 having an 
outwardly divergent access port 32 communicating said chamber with the 
exterior. 
The forward wall 33 of chamber 31 is provided with a contoured or arcuate 
surface to slidably accommodate the expanded anchor piece 34 at the end of 
connecting wire or cable 36, which registers within access opening 32. 
Said forward wall 33 of chamber 31 is of sufficient thickness that when a 
pulling tension is applied to cable 36, the resulting pressure transmitted 
through the nose piece, will cause the entire pulling head 13 to be drawn 
in the direction of the cable pull. 
Anchor piece 34 as shown, comprises generally a truncated cone which is of 
sufficient length to be movable within forward chamber 31 thereby allowing 
pulling cable 36 a degree of lateral flexibility without exerting or over 
straining either the cable or the nose piece. 
The nose piece axial cavity further includes a peripheral shoulder 40 which 
positions a transverse plate 37. The latter is welded peripherally in 
place against shoulder 40 to assure a liquid tight joint. 
Said transverse plate 37 defines a rear chamber 38 which is closed at its 
remote end by engagement of nose piece rear surface 28, with seal ring 21. 
The nose piece axial cavity terminates at a peripheral tapered seat 39 
which, when the nose piece and the clamping ring 21 are drawn together by 
bolts 29, will cause the seal ring 21 to deform thereby assuring water 
tight integrity of the annular sealed joint thereby formed. 
As seen in FIG. 3, the plurality of clamping bolts 29 which hold the nose 
piece 26 and the clamping ring assembly in tightened, sealed engagement, 
are disposed along a bolt ring adjacent to the edge of the nose piece. A 
series of grooves 41 formed longitudinally into the nose piece 26 
accommodate bolts 29 in a manner to permit insertion and removal thereof 
as required with a rotatable socket tool. Further the heads of bolts 29 
are positioned below the surface of forward face 27 to avoid contact with 
a guide member during a conduit pulling operation. 
Operationally, when a conduit 10 is to be unwound from a reel on the deck 
of an offshore platform or vessel, the conduit will have previously been 
provided with a hub or end fitting 11. Since the pulling head 13 will be 
drawn through an elongated conductor extending downwardly through the 
marine platform to the ocean floor, the forward end of the pull wire or 
cable 36 will preferbly be communicated with a messenger wire which is 
initially lowered through the elongated conductor. Thus, the wire lower 
end can be engaged with a pulling mechanism such as a winch or the like. 
The discrete clamping segments 16 and 17 are manually positioned about the 
hub 11 in a manner that the hub is registered within central passage 18 so 
that tightening of bolts 22 will draw the ring segments into close or 
abutting engagement. With the plurality of ring segments 16 and 17 
properly positioned, they are urged forward by bolts 22 whereby shoulder 
42 will contact with pressure surface 14 of annular rim 12. 
Fastening bolts 22 can now be drawn tight. Thus, the two ring segments 16 
and 17 will be progressively forced into tight engagement with each other, 
and correspondingly be forced into firm peripheral engagement with hub 11 
at surface 14. 
As shown, the remote end of the clamping ring section is provided with an 
outwardly tapered portion 20 which engages the corresponding sections of 
cable 10 hub 11 whereby the hub unit is rigidly held in place thereby to 
minimize stress at the juncture of hub 11 and cable 10. 
With seal ring 21 positioned at the face 15 of hub 11, nose piece 26 is 
aligned with hub 11 to bring the respective fastening holes into 
alignment. Clamping bolts 29 are now inserted into the ring section and 
drawn tight to bring seat 39 and rear surface 28 into abutting deforming 
engagement with seal ring 21 thus forming a peripheral sealing surface to 
avoid entry of water into the conduit as it is drawn from its reel. 
In an alternate embodiment of the disclosed pulling head, as shown in FIG. 
4, nose piece 46 is constructed, and functions similarly to nose piece 26 
of FIG. 1. Nose piece 46, however, differs in that it is provided with an 
access port 47 which communicates the rear chamber 48 with the atmosphere. 
As seen, said access port includes a lower passage 49 which communicates 
with the rear chamber 48, and a tapered section 51 which receive a tapered 
shoulder plug 52. 
A second passageway 53 which terminates at the rear face 54 of the nose 
piece 46, intersects said tapered passage 51 to provide controlled 
communication therebetween. 
An insert 56 is urged in threaded engagement with tapered plug 52 whereby 
the latter bears against the openings to both passages 49 and 53 to 
preclude passage of fluid through chamber 48. 
Functionally, should this feature be utilized in the pulling head, it 
serves as means to flush air from the rear chamber 48 to facilitate 
testing procedures which will be performed on the conduit prior to its 
being utilized. 
After a pulling head has drawn conduit 10 to its desired position, the 
latter will normally rest on the ocean floor. To engage the conduit with a 
corresponding hub, the pulling head is disengaged from the hub by a diver. 
This is achieved by first removing bolts 29 so that nose section 26 can be 
supported. Thereafter, the mating hub is positioned against seal ring 21 
and the two hubs are urged thereagainst by a peripheral ring clamp. 
Although modifications and variations of the invention may be made without 
departing from the spirit and scope thereof, only such limitations should 
be imposed as are indicated in the appended claims.