Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
W092/04525 _ PCT/GB91/01523
aIP~ SYSTE~ ;IT.J. _LLCT~IC.~L ~DUCTORS
~ESCRI~TION
The inve ,n _ion rel-~es .o a ?i D e sys.-.
ncorpora~ing cne or more elec.rical c~nduc~ors, and
more speci-ic2lly, ~o 2 ?iDe SyS~elil in ~h:-h a
pluralily o_ -l?e mem~ers or seclions are conn-_~ed
_ogether in end--o--nd _el~ nship, and in ~hi^:s -:~e
?ipe se-~icns .~ _iê onê, _~ usually mo~2 ~ _lê_~~~ -al
conductors, which are aiso _onnec_ed 'oge~:ne~ ~_
?rovide or ^-lectrical ?owe- â U p p1 V a-.^!or
communication along -he pipe sysrem.
The inven~ion is thus concerned with the provlsion
of a pipe member or section of a kind having elec~~ical
conductor means and at leas. one fluid passage
extending therealong, ~eans whereby the section can be
mechanicallv connected with a like or a co-operating
section in a piDe system, and means for effe~~ing
connection of the electrical conductor means an~ ~he at
least one -luid passage with an electrical conductor
means and a fluid passage of _he like or co-operating
sec.ion respec_ vely.
The invention provides a pipe sec'ion of this kind
including means _or isolating -he electrical conauc~o-
means from 'he rluid in the fluid passage.
The inven'ion can thus provide one or ~orecarriers or carrier 'ubes, or containing the condu~ror
or conductors, ~hich are loca~ed in the fluid passage,
or are exposed to th~ pressure of fluid in the passa~e,
and which extend between appropriately sealed
electrical connect?r assemblies at the ends of the ?ipe
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section. ~he electric conductor or conductors can
comprlse for example, conventional electrical cables.
The ?i2e section thus contains within it a conductor
assembl~ comprising electrical conductor means
S protec~ed by reception withhin a sealed compartment
~rovided by the conductor carrier means and the
_onnec-~r assemblies sealed off to the ends of the pipe
sec~ion. The lnvention has particular reference to a
drill st~ing and can be embodied as a drill pipe
section comprising a drill pipe defining within i~ a
?assage for drilling mud, and including the carrier
tube c. tubes. ~he mud passage can be defined by an
internal mud liner to ensure smooth flow of the mud and
he carrier tube or tubes can be located between the
drill ?ipe and the mud liner. The carrier tube or
tubes can thus be received in a groove or grooves
defined outwardly of the mud liner wall, as by
de~ormatlon of a tubular liner of substantially uniform
wall thickness. The carrier tubes accommodated in the
grooves can be exposed to the pressure of the drilling
mud by wav of perforations in the mud liner wall so as
to experience substantially uniform ambient pressure.
The pressure protection for the conductors is then
?rovided by the carriers, not by the mud liner. In
this way, good protection, total pressure balancing and
pressure resistance is obtained.
Usually, there will be a plurality of conductors,
typically three conductors, and the mud liner will
accordingly be provided with plural, typically three,
such grooves equi-angularly spaced around longtudinal
axis of the drill pipe section.
The invention also provides a pipe section of the
~ind described having hollow pin and box type conductor
connection means at respective ends of the pipe
sectlon, the connection means providing reliable
W092/04525 PCT/GB91/01523
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electrical connections independent of angular
orientation and permitting a substantially unobst~ucted
fluid flow from and into aajacent pipe sections.
The ends of a drill pipe section can 'hus r-ceive
wi~hin them hollow detachable _ondu-.or connec~or
assemblies the interiors of ~Aich communicate ~ith the
mud liner to provide a continuous fluid passa~e along
the drill string. The pin type assembly can ?ro~ide
contact elements 2rotruding -rom he ?iDe sectlon end
and the box ~ype assembly can ?rovide co-operating
contact elements within a socket Do-tion providing
controlled contact in the radial d -ection. The
contact elements of both assemblies can be cons_i uted
as contact -ings.
1; When embodied as a drill pipe section wi.h the
conductor arrangements described above, the conductor
carriers can extend between the assemblies whic~ can be
sealed to the pipe section wall inwardly of the contact
elements and/or to each other as -by a sealing portion
projecting beyond the contact elements for reception in
a socket portion inwardly of the contact elements of
the box-type assembly. Seal means can be arranged to
wipe clean the contact areas of the contact elements
during assemblyO
The invention can thus be readily embodied in a
drill string including electrical conductors, in which
the conductor carriers provide protection from pressure
for the conductors and their inculation. The carriers
can compensate also for the elongation experienced by
the conductors under tension. The conductor carriers
can have fixed ends, at the conductor connection
assemblies, so no dynamic seals are required. The
conductor assembly means as a whole can be axially
and/or rotationally movable relative to the pipe
section, and can have low torsional stiffness so as to
W092/04525 PCT/GB91/01523
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follow tors onal displacement of the drill pipes. The
conductors are also free to e~?and thermallv without
transmittin~ adding load to the insulation ~nen the
drill string is under high t~nslon.
The conduc~ors 'hemselves can be of conven~ onal
form, capable of ?roviding -xcellent sisnal and ?ower
transmission.
Assembly of the drill string can be _ffecred
conventionally by means of stabbing guides, after
cleaning o the conductor contacts or contac - ngs.
The electri_al com?onents of the pipe sec'ion c=n be
easily disconnecred and ret-leved f om the d- ll ?ipe
for replacement o any damaged parts, and o_ any
repai- of tne drill ?ipe se?aratelv.
The invention is further ~escribed, b~ wav of
example, with reference to .he accompanving d~awings,
in which:
Figure 1A is a perspective view with parts removed
in order to show the interior of the upper end of a
drill pipe section embodying the invention;
Fig. 13 is a like view of the lower end of the
drill pipe section of the invention;
Figures 2 & 3 are sectional side views of the
upper and lower ends of the ?ipe section respectively;
and
Figure 4 is a sectional side view of ~he end
regions of wo of the drill pipe sections embodying the
invention, assembled together.
The illustrated d-ill string comprises a plurality
of like drill pipe sections 10 of appropriate length
mechanically connected together in end-to-end
relationship. The mechanical connections are effected
by co-operating s_rew-threaded portions at the ends or
the sections, comprising an externally threaded
downwardly and inwardly tapering pin portion 11 at the
W092/04525 PCT/GB91/01523
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lower end and a cor espondingly tapered internally
hreaded box or socket oortion 12 at _he upper end for
receiving the ?in portion of the sect on immediately
above.
Internally, ~he drill ?ipe sec~ions 10 have a
substantially uniform internal diameter, exce?t near
~he upper end as will be descr bed, but the end regions
are mechanically reinforced by portions of enlarged
external diameter. ~rom ~he main length of he ?lpe
section, the external sur ace tapers outwardly to upper
and lower intermediate por ions 14 and 15, from ~nich
_ 'apers fur.her outwardly to upper and lo~er end
?ortions 16 and 17. The lower ~nd ?o~_ion 17 has an
nward step 18 at i_s free end and the pin por ion ~1
extends downwardly rom this step.
The upper end portion 16 is of greater length ~han
the lowex end portion 17 to accommodate withln i' the
box portion 12. An 0-ring seal 19 received in a
circumferential slot in the pin portion 11, adjacent
the step 18, establishes a secondary seal with the
inner surface of box portion at its upper end when the
adjacent sections are connected together, the primarv
seal being a metal-to-metal seal between the step 18
and the upper end of the pipe section below.
2i The pipe sections 10 are thus externally more or
less conventional, except for somewhat increased
dimensions at the end regions, and can be releasably
connected together in conventional manner to provide a
mechanical connection between the sections capable of
meeting typical structural and strength requirementS.
Each pipe section 12 provides internally a passage
by which drilling mud can be conveyed to the drill bit.
This passage is defined along most of the length of the
pipe section by a perforated liner 20 received within
it. Three electric conductors 22 for conveying
W092/04525 PCr/GB91/01523
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electrical ?ower and/or communication signals along ~he
drill string are located between the mud 1iner and -ne
?iPe section
To accommocate and ?osi~ion he elec~rical
conductors 22, tne mud liner waLl is -ormed wi'h '-ree
e~ui-angularl~ s~aced grooves 24 extending along Ls
length. i~ithin the grooves are ~eceived tllbuiar
conductor carriers 25 not necessarlly of circular
cross-sectlon and, if of other cross-sec__or.,
conveniently one corresponding to that ~r _he mud '-ner
grooves 24. ~ach conductor car-ier 2; extends be~ween
the end regions cf _ne sec~ on 10 an~ -eceives ~hereln
a -es?eclive one of 'he elect- ^ condu-~-~s,
^onsti uted by ~ canventional insul-,ed c-ble. ~'he
carriers 25 protect ~he conductors 22 agalnst ?ressur-
of the mud, -~hich is transmit.ed to the exteriors o_
the carriers through the perforations in the mud llner
wall and balanced within the grooves 24.
It is of course necessary to arrange 'or
continuity of the conductors 22 along the drill string
and the pipe sections 10 contain co-operating upper and
lower electrical connector assemblies 30 and 31 of 'he
pin and box type by which electrical continuity between
the conductors 22 of adjacent sections is reliably and
conveniently ensured. The assemblies ?rovide anchoring
for the ends of ~he carriers 25 and also access to the
terminations of the conductors 22. The assemblies
incorporate seals against internal mud ?ressure and can
be readily removed from and replaced within the
sections 10.
As appears ---om Figures 1A & 2, the box or remale
connector assembl~ 30 comprises a connector sleeve 32
received within 'he upper end portion of the ?ipe
section, below the threaded connector portion 12. At
its lower end, 'he sleeve 32 has a seallng portion 3~
W092/04525 2 ~ 9 ~ PCT/GB91/01523
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stepped inwardly at its lower end to rest on a matcAing
internal step 36 provided in the pipe section interior.
The saaling portion 34 has annular grooves around i'
receiving axially s?aced seal -ings 40, .or sealing to
the ?ipe section interior. Above t.~e sealing porlion
34, the sleeve 32 has three equi-angularly spaced
axially extending grooves or recesses 42 each of which
communicates with a passage 44 through the sealing
portion. The lower end of each passage ~4 provides an
upper seating f~r one of the conductor carrlers 25.
Beneath the connector assembly 30, the mud liner
is taDered inwardly and upwardlv to match the
interior of the sleeve 32, except ln ~he regions at
whi_h are formed the axial grooves 24 containing the
conductor carriers 25.
At the upper end of the sleeve 34, the interior is
enlarged to provide a socket 46 for reception of the
lower end of the male or pin connector assembly 31.
Above ~he sleeve 34, the assembly 30 includes a
conductor sleeve 50 of electrically insulating material
mounting axially spaced conductor rings 54 received in
internal annular grooves. The electrical conductors 20
extend upwardly from the carriers 2; through the
passages 44 into the grooves 42, the conductors having
outwardly inclined portions in these grooves because of
the socket 46. Jumper portions 56 at the ends of the
conductors 22 connect to leads 60 in axial passages
within the wall of the conduc~or sleeve, by which
connection is made to the conductor rings ;4.
As shown in Figures 1B & 3, the male or 2in
connector assembly 31 comprises a tubular connector
sleeve 33 received within and projecting f-om the lower
end of the s~ction 10.
At its upper end, the sleeve 33 has a sealing
portion 35, delimited below by an annular inward step
W092/04525 PCT/GB91/01523
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resting on a ma~ching s~eD 37 in the pipe section
interior The sealing ?ortion 35 engages axially
spaced seal -ings 39 n annular grooves in the pipe
section wall
Equi-angul2rly s?ace~ ?assa~es ~1 in the sealing
por.ion 35 proviae seatirqs ~or .he lower ends of the
conductor carriers 2~ and communicate with external
grooves 43 ~hich extend aownwardly to a portion 45 of
the sleeve, at .he lower end of ~he ?ipe section pin
por.ion 11, wnich rever~s .3 a complete circular cross-
sec~ion externall- but which includes apertures 47 in
alignment with the grooves 43
SligAtly below .he lower end of the pin portion
11, the sleeve exterior is inwardly stepped, and below
~he step, the sieeve 33 is surrounded by a connector
sleeve 51, of electrically insu~ating material, and a
sealing sleeve 53 the lower end of which has an
internal flange of which the inner diameter matches
that of the connector sleeve.
The conductor sleeve ;1 is externally grooved to
receive three axially spaced conductor contact rings 55
each electrically connected to a respective one of the
electrical conductors and the sealin~ sleeve 53 is
externally grooved to receive two axially spaced seal
rings 57. The conductors 22 extend downwardly from the
carriers 2; through the sealing portion passages 41 and
the grooves 43. Jumper portions at the conductor ends
connect to leads 59 in axial ?assages in the wall of
the conductor sleeve ;1, to make connection to the
conductor rings 55
At the upper end of the connector sleeve 33, the
wall of the mud liner tapers inwardly and downwardly
from a position in the region of the join between the
intermediate and end portions of the pi~e section 10,
between the portions ormin~ the grooves, so as to
W092/04525 PCT/GB91/01523
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communicate with the sleeve ~nterlor.
Assembly together of two of 'he pipe sections 10
to reach the condition of ~igure 4 is effected by
stabbing, after _leaning of .he contact .ings ~4 & 55.
As .he mechanical connection is completed the sealing
sleeve 53 is received in ,he socket 4~ and the
conductor sleeve 51 is received in the sleeve ;0, with
electrlcal contact establisned between the rings 54 &
55.
The invention can be embodied in a variety o. ways
other than as s~ecifically desc-~bed.