Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
1
TUBULAR COMPONENT WITH A HELICAL ABUTMENT
The present invention relates to a tubular component for connecting, by
makeup, to an
analogous component in order to form a contiguous pipework. Advantageously,
the invention is
of application in producing a stem formed by drill pipes, heavy weight drill
pipes and drill collars,
which are regularly fitted together and broken apart. A stem of this type may
in particular be used
when driven in rotation in order to drill hydrocarbon wells. Alternatively,
tubular components of
this type may also be used in a drill pipe riser or indeed a riser when
operating a well of this type.
Each tubular component comprises at least one end element, male or female,
which is
threaded. In general, a tubular component comprises a male threaded end
element and an opposed
female threaded end element. The threaded end element is intended to be made
up with the
complementary threaded end element of another component. When connected, the
two end
elements of the two components form a connection.
The threaded tubular components are connected under carefully controlled loads
which
comply with requirements as regards tightening and sometimes as regards the
seal, which depend on
the conditions of use. In general, a threaded end element of a connection
comprises at least one
axial abutment which is activated at the end of makeup and clamped against a
corresponding
surface by application of a predetermined makeup torque. The makeup torque
applied at the end of
tightening is known as the torque on shoulder, as it corresponds to the torque
necessary for
activation of the axial abutments.
When two components are made up one with the other, the application of too low
a torque
on shoulder, for example as a result of a premature halt to makeup, produces a
connection which
does not comply with specifications. The risks of uncoupling by jump-out or
accidental breakout
are then high. Before uncoupling per se occurs, loss of tightness may also
occur. Insufficient
tightening favours rapid wear of the connections and difficulties when it
comes to intentional
breakout.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
2
The application of too high a torque on shoulder, for example as a result of
over-torquing,
also results in a connection which does not comply with specifications.
Portions of the component
are at risk of undergoing plastic deformation and damage as over-torquing
commences. The
intended cooperation between the various surfaces of each of the components is
then no longer
guaranteed. The behaviour of the junction becomes difficult to predict.
Degradation of this type is
difficult to repair.
In order to limit these risks, a nominal upper torque on shoulder at the
shouldering torque
and a lower torque on shoulder at the yielding torque are routinely
determined. Adhering to the
nominal torque on shoulder and its range of tolerances is a guarantee of
satisfactory mechanical
strength of the connection under the envisaged conditions of use. Adhering to
this range limits the
risks of malfunction. The limits to the range of the admissible torque on
shoulder vary for each
component configuration. The nominal values for such limits depend on the
dimensions of the
components, and in particular on the thicknesses of the walls which vary as a
function of the
envisaged applications.
In practice, makeup/breakout operations are carried out on-site under
difficult conditions,
for example on offshore platforms. Actual makeup conditions may be very
different from the
theoretical conditions in a laboratory.
In the applications envisaged by the present invention, a threaded end element
of a
connection may comprise two axial abutments which are axially separated,
respectively inner and
outer, which are activated at the end of makeup and clamped against
corresponding surfaces by the
application of a predetermined nominal makeup torque. The predetermined makeup
torque for
these connections is increased by doubling the surfaces which are engaged in
abutment.
Wells to be drilled are becoming ever more complicated and ever longer, and
the torque
exerted on the upstream tubular components increases with increasing distance
between the
upstream tubular components and the downstream tubular components. The
invention improves the
situation by proposing tubular components which can be used to resist higher
operational loads by
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
3
proposing a higher nominal makeup torque than that of existing connections,
without increasing
either the outer dimensions of the connection nor the weight of the string.
Further, another
advantage of the invention is that it proposes an end element, in particular
an abutment, the integrity
of which is maintained throughout its use, and for which the seal against
liquids is ensured even
after several makeup-breakout operations.
For an identical wall thickness, a tubular component in accordance with the
invention has at
least one abutment the active surfaces of which are more extensive than those
of known tubular
components. The configuration of the invention means that the local contact
pressures are not
increased, thereby preventing plastification and guaranteeing that the
abutments hold under tension
traction and thus remain impervious even in service.
With the high makeup torque, the contact pressures on the abutment surfaces of
the
invention are subjected to loads per unit surface area which are identical to
those of conventional
annular surfaces or ring surfaces. The makeup torque beyond which
plastification phenomena may
occur is thus higher.
To this end, the invention provides a tubular drill stem component comprising
an end
element having an axis of revolution and provided with a threading extending
about the axis of
revolution, the end element being adapted to being connected by makeup onto a
corresponding end
element of another tubular component provided with a complementary threading,
the end element
comprising at least one outer abutment arranged so as to come into contact
with a corresponding
outer abutment of the other component at the end of makeup, in which said
outer abutment
comprises at least one helical surface having an axis of the helix which
coincides with the axis of
revolution.
In another aspect, the Applicant proposes a connection comprising two end
elements of two
distinct components as hereinbefore defined. The two components are connected
to each other by
making up the end element of the first component with the corresponding end
element of the second
component.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
4
The component may have the following optional characteristics, either alone or
in
combination with each other.
In particular, the threading has a thread angle such that the helical surface
or surfaces may
have a helix angle less than or equal to the thread angle of the threading.
Advantageously, the helix
angle may be in the range 0.5 to 7 .
In particular, a sum of the angular portions about the axis of revolution over
which the
helical surface extends may be in the range 180 to 360 .
As a consequence of the existence of the helical surface, the end element
further comprises a
circumferential shoulder connected to at least one of the circumferential ends
of said helical surface.
In particular, this circumferential shoulder may comprise at least one
substantially planar
surface the plane of which forms an angle with the axis of revolution in the
range 0 to 75 . In
particular, the circumferential shoulder may comprise at least one
substantially planar surface the
plane of which may be parallel to the axis of revolution or may coincide with
the axis of revolution.
In accordance with various embodiments, the circumferential shoulder may be
connected to
the helical surface via a fillet radius or an inclined plane. In particular,
when a fillet radius is
present, this may have a radius of curvature in the range 0.5 to 10.0
millimetres.
Advantageously, the end element may comprise two abutments, an inner abutment
and an
outer abutment, each of the two abutments comprising at least one
circumferential shoulder.
Alternatively, the end element may comprise these two abutments, respectively
the inner abutment
and the outer abutment, such that only the outer abutment is provided with a
helical surface.
In particular, the end element may comprise a single helical surface located
solely on the
outer abutment.
Advantageously, the helical surface may be at a distance from the threading; a
distance
between a threading end and the helical surface may in particular be at least
8 mm.
More particularly, the invention also concerns a connection comprising two
components in
accordance with the invention, in which one of the outer abutment of a
component or the
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
corresponding outer abutment of the other component is disposed at a free
distal end of its end
element.
Other characteristics, details and advantages of the invention will become
apparent from the
following detailed description and accompanying drawings in which:
5 - Figure 1 is a longitudinal partial sectional view of two components in
accordance with the
invention;
- Figure 2 is a perspective view of a male end element of a component in
accordance with the
invention;
- Figure 3 is a perspective view of a variation of a male end element of a
component in
accordance with the invention;
- Figure 4 is a perspective view of a female end element of a component in
accordance with
the invention, corresponding to that of Figure 3;
- Figures 5 to 8 are perspective views of variations of a detail of an end
element of a
component in accordance with the invention;
- Figures 9, 10 and 11 are perspective views of variations of a male end
element of a
component in accordance with the invention;
- Figure 12 is another variation of a male end element, provided with three
helical surfaces in
accordance with the invention.
The drawings and description below essentially contain elements of a specific
nature. Thus,
they may not only serve to act towards a better understanding of the present
invention, but also
contribute to its definition if necessary.
A first tubular component 1 and a second tubular component 101 are represented
in Figure
1. The components 1 and 101 are generally in the form of a body of revolution
about an axis of
revolution )0C. In Figure 1, the components 1 and 101 are aligned with each
other. The axes of
revolution )0( therefore coincide. The direction of the axis of revolution )0(
is termed the axial
direction.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
6
In order to facilitate comprehension, the numerical references for the second
component 101
are greater by 100. Each of the components 1 and 101 comprises an end element
2 or respectively
103. Here, the first component 1 comprises a male end element 2 (or pin),
while the second tubular
component 101 comprises a female end element 103 (or box). The components 1
and 101 each
comprise a regular tube portion 9 or 109. The regular portion 9 of the tube is
integral with the male
end element 2 and at an opposite end is also integral with a second female end
element (not shown)
which is identical to the female end element 103. Similarly, the regular tube
portion 109 is integral
with the female end element 103 and at an opposite end is also integral with
another male end
element (not shown) which is identical to the male end element 2.
The regular tube portions 9 and 109 of the two components 1 and 101 are
similar to each
other. The tubular components 1 and 101 are impermeable in structure and in
material. In
particular, the tubular components form metallic structures, in particular
produced from steel or
Inconel. As an example, the grade of the material is of the order of 130 ksi,
with a yield strength in
the range 120 000 to 140 000 psi; however, it may also be selected from higher
grades of about 140
ksi, 150 ksi and 165 ksi, as well as from lower steel grades such as those
defined at about 80 ksi or
95 ksi or even 110 ksi. The end elements 2 and 103 may be produced from a
material which is
identical to or different from that of the tubes 9 and 109.
Here, the end elements, in particular 2 and 103, have a configuration which
conforms with
the standard API-7 or API-RP-7G or indeed I50-10407-1. In variations, the end
elements 2 and
103 have a proprietary configuration, for example as marketed under the
trademark VAMO
Express, or indeed as described in the publications W0-2006/092649 or W0-
2012/089305.
The regular portion 9 is generally cylindrical in shape and has a length in
the range 5 to 15
metres for long components, for example drill pipes, and 1 to 5 metres for
short components, for
example wear inserts used at the well head. The inner diameter is, for
example, in the range 25 to
400 millimetres, while the external diameter is in the range 50 to 500
millimetres.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
7
The component 1 may be obtained by friction welding the end elements to each
end of a
tube forming the regular portion 9. The same mode of production may be
employed for the
component 101. In such cases, the ends of the regular portion 9 may have
already been forged,
upset or thickened so as to increase the radial surface of the metal. As can
be seen in Figure 1, a
weld plane 5 or 105 is respectively formed at the junction between the regular
tube portions 9 and
109 with the end elements 2 and 103 respectively. Alternatively, the tubular
component may be
integral, namely without a weld, obtained from a single blank. The regular
portions 9, 109 are not
shown in Figures 2 to 8.
The end elements 2, 103 are generally tubular in shape. The end elements 2,
103 have an
exterior surface 11, respectively 121, which is substantially cylindrical.
The end elements 2, 103 carry an interior surface 17, respectively 127, or
bore, which is
substantially cylindrical.
In general, the surfaces of revolution of the components 1 and 101 are
substantially
concentric with a centre belonging to the axis of revolution )0C. The
thicknesses of the walls of the
components 1, 101 are substantially homogeneous in circumference, except at
the positions of the
end elements.
In use, the components 1 are manipulated using rams. The rams will hold the
components 1
by means of their end elements 2 or 103. The end elements 2 and 103 are better
suited to
withstanding the loads applied, in particular during makeup/breakout
operations. In particular, the
exterior contact surfaces 11 or respectively 121 locally have a largest
exterior diameter intended to
be taken up in the jaws of working tongs in order to guarantee the final
makeup torque of the
connection to be formed. This exterior contact surface is that which will come
into frictional
contact against the walls of the well during rotation of the drill stem.
Reference will now be made to Figures 1, 2 and 3 which represent three
embodiments of a
male end element 2 of a component 1. The male end element 2 comprises a
substantially tapered
exterior surface 12 in which at least one exterior threading known as the male
threading is formed.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
8
The end element 2 further comprises an end surface 13 and a central surface
16. The exterior
tapered surface 12 is located axially between the end surface 13 and the
central surface 16. The end
surface 13 and the central surface 16 are free of any threading. In the
example shown, the end
surface 13 and the central surface 16 have a substantially cylindrical
profile.
In the example shown, the tapered exterior surface 12 with the threading
comprises a
threading having a single-start thread.
The end surface 13 connects to a surface 15 extending substantially in
accordance with the
thickness of the end element 2, substantially perpendicular to the end surface
13. This surface
forms an inner abutment 15. The inner abutment 15 defines the free distal end
of the end element 2
of the component 1 in the disconnected condition. This inner abutment 15
connects on the inside to
an interior surface 17 which is substantially cylindrical. The inner abutment
15 is termed the male
inner abutment.
The central surface 16 is connected to the exterior contact surface 11 via a
surface which
extends substantially along a portion of the thickness of the end element 2.
This surface forms an
outer abutment 18. The outer abutment 18 forms an exterior shoulder of the end
element 2 of the
component 1. The outer abutment 18 is termed the male outer abutment.
Advantageously, at least one of the inner abutment 15 and the outer abutment
18 has a
helical surface. In the case in which the end element 2 has a single helical
surface, this helical
surface is produced on the outer abutment 18, as was the case with the helical
surface 38 of Figure
2.
In Figure 2, the helical surface 38 is at a distance from the threading. An
axial length D1 for
the central surface 16 which is free of threading may be defined; in
particular, this distance D1 is at
least 8 mm and, for example, less than 24 mm. This distance D1 corresponds to
the minimum axial
distance along the axis XX between the helical surface 38 and the
substantially tapered exterior
surface 12 carrying the threading.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
9
The helical surface 38 is defined by an axis of the helix which coincides with
the axis of
revolution XX. The sense of the helix of the helical surface 38 corresponds to
that of the threading
of the tapered exterior surface 12. The helical surface 38 has a helix angle
which has the reference
a (alpha). The threading of the tapered exterior surface 12 has a thread angle
with reference 0
(beta). The helix angle a of the helical surface 38 in this example is equal
to the thread angle 0 of
the threading.
By definition, the helical surface 38 is not flat. From another viewpoint, the
helical surface
38 defines a surface the position of which varies along the axial direction as
a function of the
angular portion of the component 1, or angular sector, under consideration.
In Figure 2, the outer abutment 18 is connected to the exterior surface 11 via
an annular
chamfer 20.
In a variation, shown in Figure 3, the end element 2 is shown with two helical
surfaces, such
that the inner abutment 15 comprises a helical surface 35 and the outer
abutment 18 comprises the
helical surface 38.
In Figure 3, the helical surface 35 is also at a distance from the threading.
An axial length
D2 of the end surface 13 which is free of threading may be defined, this
distance D2 in particular
being at least 8 mm, for example less than 24 mm. This distance D2 corresponds
to the minimum
axial distance, along the axis XX, between the helical surface 35 and the
substantially tapered
exterior surface 12 carrying the threading. This distance D2 also corresponds
to the axial distance
between the free distal end of the end element 2 and the threaded exterior
surface 12.
In the embodiments of Figures 2 and 3, each angular portion of the helical
surface 38
extends in a radial direction, i.e. perpendicular to the axis of revolution
XX. In other words, the
profile of the helical surface 38, viewed in a longitudinal section passing
through the axis of
revolution XX, may be represented by a straight segment orientated in a radial
direction. The width
of the helical surface 38 is thus substantially equal to the radial distance
of the outer abutment 18.
Analogous reasoning applies to the helical surface with respect to the inner
abutment 15.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
In variations (not shown), the profile of the helical surface 38 may be
straight and have a
non-zero inclination with respect to a radial direction. In this case, the
helical surface 38 has a
generally tapered configuration. The width of the helical surface 38 is thus
substantially greater
than the radial thickness of the outer abutment 18. In other variations, the
profile of the helical
5 surface 38 may be curved, for example concave or convex. The radial width
of the helical surface
38 is thus substantially greater than the outer abutment 18.
In the embodiments of Figures 2 and 3, the helical surfaces 35 and 38 extend
over the whole
circumference of their respective abutments, i.e. approximately 360 . The
helix angle a of the
helical surfaces 35 and 38 are substantially identical. In this example, the
helix angle a is
10 substantially equal to the thread angle 0 of the threading of the
tapered exterior surface 12. The
helix angle a of the helical surface 38 is in the range 0.5 to 7 , for
example.
The presence of the helical surfaces 35 and 38 results in the formation of a
circumferential
shoulder 36 or respectively 39 on each of the abutments 15 and 18. The two
circumferential
shoulders may be substantially planar, each forming a plane comprising the
axis )0C. They may be
designed so as to be in the same plane.
The outer abutment 18 of the end element 2 thus comprises the circumferential
shoulder 39.
The circumferential shoulder 39 extends over an axial position of the end
element 2 which is
identical to that over which the helical surface 38 extends. When the helical
surface 38 is 360 , the
circumferential shoulder 39 connects the two circumferential ends of the
helical surface 38 one to
another.
Figure 5 shows a detail of the circumferential shoulder 36 of the embodiment
of Figure 3.
The two circumferential ends of the helical surface 35 are aligned in the
axial direction, and so here,
the circumferential shoulder 36 exhibits a zero circumferential component. In
the example of
Figures 2 and 3, the circumferential ends of the helical surface 38 are
aligned in the axial direction,
with the circumferential shoulder 39 here having a zero circumferential
component. In these
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
11
configurations, the circumferential shoulder 39 defines a plane passing
through the axis XX. In
particular in Figure 3, the circumferential shoulders 36 and 39 are defined in
the same plane.
In Figure 6, the circumferential shoulder 36 comprises a substantially planar
surface. The
plane of the planar surface forms an angle y (gamma) with the axis of
revolution XX. In the
embodiments of Figures 2 and 3, the plane of the respective planar surface of
the circumferential
shoulders 36 and 39 here is substantially coincident with the axis of
revolution XX. The angle y is
thus substantially zero. The planar surface of the circumferential shoulders
36 and 39 extends
substantially perpendicular to the helical surfaces 35 and 38, plus or minus
the helix angle a.
In the example of Figure 2, the circumferential shoulder 39 is connected to
both of the
circumferential ends of the helical surface 38 via sharp borders or edges.
This is also the case in
Figure 3 for the circumferential shoulders 36 and 39.
Figures 6, 7 and 8 show variations of the helical surfaces. To make these
variations more
legible, they are shown on the inner abutment 15. Clearly, each of the
variations may also be
applied to the embodiment in which the helical surface is on the outer
abutment 18 as shown in
Figures 9, 10 and 11. These variations are primarily distinguished from the
embodiment of Figure 3
in that the helical surface 35 extends over an angular portion of less than
360 . The two
circumferential ends of the helical surface 35 are out of alignment in the
axial direction. The
circumferential shoulder 36 linking them has a non-zero circumferential
component. The
circumferential shoulder 36 extends over an angular portion of several
degrees, for example
between 1 and 15 .
In the variations of 6, 7 and 8, the profile of the surfaces of the
circumferential shoulder 36,
viewed in a longitudinal section passing through the axis of revolution XX,
may be represented by
straight segments orientated in a radial direction. As was the case for the
helical surface 35, in a
variation the profile of the circumferential shoulder 36 is straight and has
an inclination with respect
to a radial direction. In other variations, the profile of the surfaces of the
circumferential shoulder
36 may be curved, for example concave or convex.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
12
In the variation of Figure 6, the circumferential shoulder 36 comprises a
substantially planar
surface. The plane of the planar surface forms an angle y with the axis of
revolution XX. Here, the
angle y is non-zero, for example in the range 00 to 75 . As was the case with
Figure 2, the
circumferential shoulder 36 is connected to both of the circumferential ends
of the helical surface 35
via sharp borders or edges.
In the variation of Figure 7, the circumferential shoulder 36 comprises two
fillet radii, one
being concave and the other, convex. The fillet radii each have a radius of
curvature, respectively
with references R1 and R2. The connections between the circumferential
shoulder 36 and the
helical surface 35 do not have a sharp border or edge. In a variation, not
shown, the circumferential
shoulder 36 might not have a planar surface, so that the fillet radii are
connected to each other via a
point of inflexion in a manner such that the circumferential shoulder 36 forms
a substantially
continuous link between the two circumferential ends of the helical surface
35. Here, the radii of
curvature R1 and R2 are substantially equal. The radii of curvature R1 and R2
are in the range 0.5
to 10 millimetres, for example.
In the variation of Figure 8, the circumferential shoulder 36 comprises two
substantially
planar, mutually intersecting surfaces. A first plane 36' forms a zero angle y
with the axis of
revolution XX. In contrast to the case of Figure 3, the planar surface is
connected to one of the two
circumferential ends of the helical surface 35 via a second plane 36" in the
form of a chamfer, here
at substantially 45 . Here, the chamfer is provided on the side of the concave
connection with the
helical surface 35. Instead of or in addition, a chamfer may be provided on
the side of the convex
connection with the helical surface 35.
In other variations, the helical surface 35 extends over a little more than
360 , i.e. one turn
plus a few degrees, for example between 361 and 365 . The circumferential end
portions of the
helical surface 35 are then slightly superimposed in the axial direction at a
singular angular portion
of the component 1. The circumferential shoulder 36 is then shaped into a
concavity connecting the
two circumferential ends of the helical surface 35 with each other.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
13
In a variation of Figures 9, 10 and 11 (not shown), the inner abutment 15
might not have a
helical surface, while the inner abutment is provided with a single helical
surface in one of the
variations.
In other embodiments, the abutment 15 comprises a helical surface 35 which
extends over
an angular portion which is significantly less than 360 , for example less
than 270 , or more
preferably less than 180 or less than 90 .
In the cases in which the helical surface extends over an angular portion of
significantly less
than 360 , the abutment then comprises said single helical surface, a single
circumferential shoulder
and the remaining angular portion of the abutment which then defines a surface
in the form of a
portion of a ring. The profile of the surface in the form of a portion of a
ring, viewed in longitudinal
section, may be planar and parallel to a radial direction, planar and inclined
with respect to a radial
direction or indeed curved, for example convex or concave. The abutment 18
comprises the surface
in the form of a portion of a ring, the helical surface 38 and the
circumferential shoulder 39, in
succession along the circumference. In this case, the circumferential shoulder
39 connects a
circumferential end of the helical surface 38 to a circumferential end of the
surface in the form of a
portion of a ring.
In a variation, Figure 12, the abutment 18 comprises at least two helical
surfaces 38. The
abutment 18, as a consequence, comprises as many circumferential shoulders 39
as there are helical
surfaces 38. The abutment 18 comprises, in succession along the circumference,
a first helical
surface 38', a first circumferential shoulder 39', a second helical surface
38", and a second
circumferential shoulder 39". In the example of Figure 12, the inner abutment
15 also has a helical
surface 35, and so it constitutes an embodiment with three helical surfaces.
In accordance with the invention, the presence of N helical surfaces may be
combined with
N planar surfaces in the form of a portion of a ring. The abutment then
comprises a succession of N
ensembles along the circumference, constituted by a helical surface, a surface
in the form of a ring
and a circumferential shoulder.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
14
The sum of the angular portions over which the N helical surfaces extend is,
for example, in
the range 180 to 360 .
Each characteristic, embodiment, variation and combination which derives from
the
description above in respect of the abutment 15 can be transposed to the
abutment 18 and vice
versa. Furthermore, the first end element 2 of a component 1 may comprise:
i) an abutment 15 in accordance with one of the embodiments described above
on the
inside and an abutment with configuration which is known per se on the
outside;
ii) an abutment 18 in accordance with one of the embodiments described
above on the
outside and an abutment with configuration which is known per se on the
inside;
a combination of an abutment 15 in accordance with one of the embodiments
described above on the inside and an abutment 18 on the outside, the abutments
15 and 18 being
analogous; or
iv) a combination of an abutment 15 in accordance with one of the
embodiments
described above on the inside and an abutment 18 in accordance with one of the
embodiments
described above on the outside, the abutments 15 and 18 having different
configurations.
The circumferential shoulders 36 or respectively 39 may be disposed in the
same angular
portion of the component 1, as seen in Figure 3, or be offset with respect to
each other.
Reference will now be made to Figures 1 and 4, representing two embodiments of
a female
end element 103 of a component 101. The female end element 103 of Figure 4
corresponds to and
matches the shape of the male end element 2 of the component 1 of Figure 3.
Because the shapes
match, at the very least it is to be expected that the inner abutment 15 and
outer abutment 18 can be
placed in sealing engagement over 360 with the corresponding surface carried
by the female end
element 103, and that the threaded portions can be engaged together.
The female end element 103 comprises a substantially tapered interior surface
122 in which
an interior threading is provided. The end element 103 further comprises an
end or distal surface
126 and a central or proximal surface 123. The threading of the interior
tapered surface 122 is
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
located axially between the end surface 126 and the central surface 123. The
end surface 126 and
the central surface 123 are free of a threading. The end surface 126 and the
central surface 123 are
substantially cylindrical and match the shape of the central surfaces 16 and
the end surfaces 13 of
the male end element 2. A space is provided between these respective
cylindrical portions in order
5 to form a backflow zone for grease deposited on the threads; this grease
might have been deposited
in a quantity which is larger than the residual interstitial space provided
between the threads at the
end of makeup.
The end surface 126 has a diameter which is larger than that of the central
surface 123. The
threading of the interior tapered surface 122 is located radially between the
end surface 126 and the
10 central surface 123.
During connection, the axis of makeup corresponds to the axis of revolution
)0C. The sense
of makeup is imposed by the sense of the complementary threadings of the
exterior 12 and interior
122 tapered surfaces. The embodiment of Figures 3 and 4 comprises threadings
with a conventional
makeup sense, i.e. the end elements 2, 103 have right handed threads.
15 The
central surface 123 and the interior surface 127, both substantially
cylindrical, are
connected to each other via a surface extending substantially along a portion
of the thickness of the
end element 103. This surface forms an abutment 125. The inner abutment 125
forms an interior
shoulder of the end element 103 of the component 101.
The end surface 126 and the exterior surface 121, both substantially
cylindrical and
concentric, are connected one to the other via a surface extending
substantially along the thickness
of the end element 103. This surface forms an outer abutment 128. The outer
abutment 128 defines
the free distal end or terminal end of the end element 103 of the component
101 in the uncoupled
state.
Because of their respective radial positions, the inner abutment 125 may be
termed the
female inner abutment, while the outer abutment 128 may be termed the female
outer abutment.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
16
The inner abutment 125 of the end element 103 of the component 101 corresponds
to the
inner abutment 15 of the end element 2 of the component 1. The shape of the
abutment 125
matches that of the abutment 15. The abutment 15 and the abutment 125 are
arranged so as to come
into clamping contact one against the other at the end of makeup, and so as to
obtain, at all points of
the inner abutment 15 facing the abutment 125, a sufficient contact pressure
to ensure a seal against
fluids, at least to liquids.
The outer abutment 128 of the end element 103 of the component 101 corresponds
to the
outer abutment 18 of the end element 2 of the component 1. The shape of the
abutment 128
matches that of the abutment 18. The abutment 18 and the abutment 128 are
arranged so as to come
into clamping contact one against the other at the end of makeup, and so as to
obtain, at all points of
the outer abutment 18 facing the abutment 128, a sufficient contact pressure
to ensure a seal against
fluids, at least to liquids.
In a connection obtained when the two components 1 and 101 are connected one
with the
other by makeup, the end element 2 of the first component 1 corresponds to the
end element 103 of
the second component 101. The N helical surfaces 35, respectively 38, are
homologues of the N
helical surfaces with references 145, 148 respectively and the N
circumferential shoulders 36 or
respectively 39 are homologues of the N circumferential shoulders 146,
respectively 149 provided
on the end element 103.
In Figure 4, the helical surface 148 is distant from the threading. The end
surface 126 which
is free of a threading covers an axial distance D3 along the axis XX, distance
D3 being not
necessarily equal to the axial distance Dl. This axial distance D3 also
corresponds to the distance
between the free distal end of the end element 103 and the threaded interior
tapered surface 122. is
This non-zero axial distance D3 is at least 8 mm and, for example, less than
24 mm.
The threadings of the exterior 12 and interior 122 tapered surfaces are
complementary.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
17
Here, the threadings of the exterior 12 and interior 122 tapered surfaces have
a single thread.
In a variation, the threadings comprise several threads, for example two,
three or four. These are
known as multi-start threadings. The threadings have a constant pitch.
The operation for connecting the two components 1 and 101 will now be
described. In the
example of Figure 1 or Figures 3 and 4, the male end element 2 of the first
component 1 is
connected together with the female end element 103 of the second component
101. This is
equivalent to connecting the male end element (like 2) of the second component
101 with the
female end element (like 103) of the first component 1. Each of the surfaces
of the first component
1 mentioned above can then cooperate with a corresponding surface of the
second component 101.
During an uncoupling operation, i.e. breakout, the following events and their
order are reversed.
Before connection, the components 1 and 101 are aligned one with the other
such that their
axes of revolution )0( coincide and the male element 2 of the first component
1 is disposed facing
the female end element 103 of the second component 101.
At the start of connection:
- the male end element 2 is partially inserted into the female end element 103
by means of a
translational movement along the axis of revolution )0( to bring the
components 1, 101 towards
each other;
- using a screwing movement, the threading of the exterior tapered surface
12 and the
threading of the interior tapered surface 122 come into engagement with each
other.
- At the end of screwing up:
- the exterior surfaces 11 and 121 are substantially in the extension of
each other in the
axial direction and are drawing closer to each other;
- the interior surfaces 17 and 127 are substantially in the extension of
each other in the axial
direction and are drawing closer to each other;
- the abutment 15 comes into contact against the abutment 125. In other words,
the inner
abutments 15 and 125 come into contact with each other;
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
18
- the abutment 18 comes into contact against the abutment 128. In other
words, the outer
abutments 18 and 128 come into contact with each other;
- the N helical surfaces 35 come into contact against the N helical
surfaces 145. In other
words, the helical surfaces 35 and 145 come into contact in pairs;
- the N helical surfaces 38 come into contact against the N helical surfaces
148. In other
words, the helical surfaces 38 and 148 come into contact in pairs;
- the N circumferential shoulders 36 approach each other facing the N
circumferential
shoulders 146. In other words, the circumferential shoulders 36 and 146
approach each other in
pairs;
- the N circumferential shoulders 39 approach each other facing the N
circumferential
shoulders 149. In other words, the circumferential shoulders 39 and 149
approach each other in
pairs.
At the end of tightening:
- the exterior surfaces 11 and 121 form a quasi-continuous exterior surface
passing from
one component 1, 101 to the other;
- the interior surfaces 17 and 127 form a quasi-continuous exterior bore
passing from one
component 1, 101 to the other;
- the abutment 15 is in clamping contact against the abutment 125, which
means that a large
makeup torque can be applied;
- the abutment 18 is in clamping contact against the abutment 128, which means
that a large
makeup torque can be applied;
- the circumferential shoulders 36 and 146 are in contact or almost in
contact;
- the circumferential shoulders 39 and 149 are in contact or almost in
contact.
The abutments in accordance with the invention comprising at least one helical
surface
have a larger active surface than abutments constituted by a surface in the
form of a planar ring
perpendicular to the axis of revolution )0( as is known in the prior art.
Shaping helical surfaces,
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
19
for example by machining, into the planar surfaces of a tubular component
means that the load
transmission surface can be increased. The radial dimensions of the end
element, such as the
internal and external diameters and the thickness of the tubular wall, remain
unchanged. The risks
of malfunction in use and the difficulties during breakout operations are
reduced.
As an example, for an embodiment in accordance with Figure 3 with helical
surfaces
respectively formed on the outer abutment and the inner abutment, the
following results are
obtained for a connection with a single-start thread in the threaded zone:
External
Helix angle a of Nominal makeup Gain due to presence of
diameter of
helical surfaces torque for a connection two helical surfaces 35 and
tube 9 and
109 (degrees) free of a helical surface 38/nominal
makeup torque
73.02 mm 8 135 N.m
(2 7/8 inch) 2.1566 (6 000 ft.lbs) +3.77%
101.6 mm 38 505 N ;m
(4 inch) 1.3103 (28 400 ft.lbs) + 2.29%
168.27 mm 130 294 N.m
(6 5/8 inch) 0.7309 (96 100 ft.lbs) + 1.28%
and the following results with the same configuration with two helical
surfaces, but in this case
provided with a double-start thread in the threaded zone:
External
Helix angle a of Nominal makeup Gain due to presence of
diameter of
helical surfaces torque for a connection two helical surfaces 35 and
tube 9 and
109 (degrees) free of a helical surface 38/nominal
makeup torque
73.02 mm 8 135 N.m
(2 7/8 inch) 4.3071 (6 000 ft.lbs) + 7.53%
101.6 mm 38 505 N ;m
(4 inch) 2.6192 (28 400 ft.lbs) + 4.57%
168.27 mm 130 294 N.m
(6 5/8 inch) 1.4615 (96 100 ft.lbs) + 2.55%
The higher the pitch of the thread, the larger may be the helix angle, and as
a consequence
the beneficial effect on the improvement of the nominal makeup torque may be
obtained.
CA 02966957 2017-05-05
WO 2016/091871
PCT/EP2015/078967
It will be noted that advantageously, the gain in terms of the final makeup
torque is larger
when the thread is multi-start. Because the thread pitch is greater when there
are more thread
starts, increasing the thread angle means that an increase in the helix angle
can be obtained.
It will also be noted that another significant advantage can be obtained on
the improvement
5 in gains on the small diameters of tubular components, often disposed at
the very bottom of the well
at a long distance from the head of the drilled well and on which it is
hardest to generate high
makeup torques.
The distance separating the circumferential shoulders 39 and 149 on the
outside is visible
from the outside of the connection. This can therefore constitute a visual
indicator to operators
10 monitoring the quality of makeup.
When the circumferential shoulders 39 and 149 and if appropriate 36 and 146
come into
contact, the reactional force opposing makeup increases abruptly. The
circumferential shoulders 36
and 146 or respectively 39 and 149 then form circumferential abutments to stop
makeup. The
torque necessary to continue makeup increases abruptly. This abrupt increase
is readily detectable
15 by makeup tools equipped with dynamometric sensors. Makeup can be
stopped before over-
torquing occurs. Stopping makeup when an abrupt increase in the torque is
detected may be
automated. The risks of damaging the end elements such as 2 and 103 of the
components 1, 101 of
the connection are reduced.
The invention is not limited to the examples of components and connections
described
20 above, given solely by way of example, but it encompasses any and all
variations that the skilled
person may envisage in the context of the claims below.
