Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~2~ 33~
HYDRAULIC ~ULTIS~AGE TURBINE OF ~URBODRI~L
The present invention relates to downhole motors
or driving rock destruction drilling tools and more
particularly to ~urbodrill hydraulic multistage turbines
using, for example, water, clay drilling mud, oil-base
drilling mud as a drilling fluid.
A turbine ox the invention is essentially a multitude
ox axially alternating stators and rotors secured res-
pectivel~ in the housing and on the shalt of a turbodrill.
the stator and rotor arranged in succession in the direc-
tion ox flow axis make up a turbine stage.
All stages of a multistage turbine have equal inside
and outside diametrical dimensions and an axial dimension.
In each stage the stator and the rotor are provided
with a ring and a spacing sleeve.
Any ring has a slow channel and a hub carrying a res-
pective bladiLg comprising a plurality of blades equally
spaced in the flow channel, and a rim.
The spacing sleeves serve or securing respective
rig in the housing and on the shalt of a turbodrill and
or enæurlng uniform alternation ox the stator and rotor
rings throughout the entire length ox a multistage turbine.
All hydraulic turbines known at present time, including
turbodrill multistage turbines are made with the stator
and rotor rings sealed along the clearances between the
revolving and sta-tionary parts ox the turbine in order to
provide a maximum possible prevention of leaks of the -
--2
2~ 3~ S
drilling fluid past the flow chapel with the bladi~.
To this end the clearances in hydraulic turbines, especial-
ly the radial clearances, are made as minimum as possible
and the value thereon is governed by adaptability to as-
sembly.
The known turbodrill turbines have a value ox the
radial clearance within the limits oi 0.5 to 1 mm. These
turbines are characterized by an increased rotational
speed ox the shaft which has an adverse eject on service-
ability ox roller-cutter drilling bits.
Besides, due to commensurability ox di;~ensions oi
the solid phase contained in the drilling fluid and the
radial clearances, a substantial portion of the moment
ox force is lost in the known turbines because ox friction
in the fluid leading to rapid wear ox turbines and impai-
ring their energy characteristic.
no in the prior art i5 a turbodrill m~istage
turbine a or example, ERG Patent No.2,942s782), whe-
rein in order to increase the torque and e~icienc~ a hub
ox an upstream ring prom a pair ox adjacent rings par-
tially overlaps the slow channel of a succeeding ring on
the side ox its radial clearance.
The given turbine has an increased rotational speed
which prevents it from being e~eotively used or driving
ro~ler-cutter drilling bits.
In addition, prom 5 to 40% ox the torque (depending
on the concentration ox a solid phase) is lost in this
--3--
3~35
turbine because oi mechanical friction between the rotors
and sta tors along the radial clearances.
It is an object ox the present invention to provide
such a turbodrill turbine the construction ox which will
ensure a reduced rotational speed or improving the opera-
ting conditions or roller-cutter drilling bits and also
or minimizing toe losses ox the moment ox force due to
friction it the drilling fluid by providing special means
to ensure communication between the space at the entry
in the ring blading and at the exit therefrom.
he exact nature ox the invention resides in that
in a turbodrill multistage turbine each stage ox which
comprises a stator and a coaxially disposed rotor each
ox which has a spa¢ing sleeve and a ring with a slow
channel Por passing the drilling fluid and a hub carr~i~g
a blading and a rim arranged in the slow channel, the bla-
des oi at least a umber of the rings being made with an
ankle ox the camber lint curvature greater Han an acute
angle wormed by the tangent to this line a-t the exit of
the bladi~g and the axis ox drilling fluid slow, according
to -the invention in a s-tage comprising at least one bla-
ding with said curva-ture ox the chamber lie the ring
wit such bladin~ is made with by-pass channels arranged
hydrau~cally parallel to the slow channel ox the ring
and co~mu~icating the space betwsen this rink and the
upstream rink with the space between this ring and the
succeeding downstream ring or discharging part ox the
z~
drilling fluid prom the slow channel.
The by-pass channels made hydraulically parallel to
the slow channels accommodating the blades with said cur-
vature ox the camber line provide for automatic regulation
ox the drilling fluid flow rate depending on the mode ox -
turbine operation. Due to an increase in ~draulic friction
ox the bladi~g with said blades taking plaoe in the period
prom the stalling mode to the no-load running condition
as the turbine gaits speed, the slow rate oi -the fluid deli-
vered to the blading will continuously decrease my virtue
ox discharging par of the fluid in the by-pass-channels~
with the result that the turbine rotatlonal speed is redu-
cedO
It is most preferable to make the by-pass channels
in the form ox an annular space between the rotor spacing
sleeve and the stator ring, the ratio ox toe radial di-
me~sion ox the annular space to the axial dimension ox
the ring being preferably in the range ox 0.2 to 1Ø The
lower limit ox said me equal to 0.2 is dictated, accor-
ding to the experimental data by the beginning ox an
intensive regulation ensuring a substantial decrease in
the ro-tational speed. the upper limlt equal to 1.0 is gover-
~edLby overall actual diamotrical dimensions ox turbodrill
tu~b~ses~
l this case in addition to a decrease in -the turbine
rotational speed, the losses ox the Moment ox force caused
by rotation it the d~llling fluid containing a solid phase
--5--
3~
are reduced and radial wear ox the turbine is practical
eliminated.
For this reason it is preferable 5O make the by-pass
channels in the Norm of an annular space between the
stator spacing sleeve and the ro-tor ring, the ratio ox the
radial dimension ox the annular space to the axial dimen-
sion ox the ring bel~g preierably selected prom a range
ox 0.14 to 0,5~ the lower limit equal to 0.14 is dictated
by the dimension of the solid phase amounting to 105 mm
which is most characteristic oY drilling fluids. The
upper limit equal to 0.5 is conditioned by the tact that
its further increase and a respective reduction ox the ro-
tational speed due to regulation the iluid slow rate
jails to compensate or a rise of the rotational speed
because ox decrease it the can diameter ox the rotor slow
channel.
In order to rationally utilize the overall diametri-
cal dimensions oi a turbine and also to intensify regula-
tion ox the flow rat, the by-pass channels may be advan-
taæeously made in the body ox the stator and rotor hub.
For preventing the fluid leaks pa the flow channel
at a stalllng mode9 i-t is expedient to have the generating
line ox the hub suriace worming the slow channel ox a riDg
posed upstream from the ring with by-pass charnels on
thy e ox the by-pass channel at the exit, inclined
prom top to bottom relative to the slow axis. For the
same reason, it is preferable that the hub ox a ring
-6-
233~
.
disposed upstream prom the ring with by-pass channels
partially overlaps its flow charnel on the side ox the
by-pass channel.
When the by-pass channel is made it the body oi a hub
then in order to prevent the fluid leaks past the slow
channel at a stalling mode, it is desirable that the rim
oi a ring.disposed upstream prom the ring with the by-pass
chan~el~ should partially overlap its slow channel on
the side oi the bypass channel.
The.inve~ti:on will now be described in greater de-tail
with reverence -to specific embodimen-ts thereo~,-taken
in conJunction with the accompanying drawings, wherein:
igs. 1a and 1b illustrate a general view ox a turbo-
drill with a bit in the bore hole, comprising a multistage
turbine, according to the invention;
Fig. 2 it an exploded view of a turbine stage, accor-
ding Jo the invention;
; jig. 3 illustrates an alternative embodiment ox the
~urb~neq according to the inventionS with a b~-pass channel
in the Norm ox an annular spaoe between the rim ox a stator
and the ~pa¢i~g sleeve ox a rotor;
ig. 4 it a cylindrical section taken on the line
n ~Y-IV ox a turbine blading ox Fig. 3 (developed on a plane
or clarity);
ig. 5 shows an alternative embodiment oi the turbine,
a~c~ ng to the invention, with by-pass channels in
the body ox stator and rotor hubs;
-7-
,
3 5
ig. 6 illustrates an alternative embodiment oi the
turbine according to the invention, with the generating
line ox the hub surface worming -the flow channel on
the side ox one by-pass channel disposed downstream prom
the rotor, inclined from top to bottom relative to the
flow axis, and also with partial overlapping ox the rotor
slow chann0l by the stator rip on the side ox another
by-pass channel;
Fig. 7 illustrates an alternative embodiment ox the
turbine9 according to the invention, with by-pass channels
in the Norm of annular spaces between .he rinks ox a stator
and the spaciDg sleeve ox a rotor, and the ring ox a rotor
and the spaain~ sleeve ox a stator.
A hydraulic multistage t~rbi~ is a working member
of a turbodrill (Figs. 1a and qb), wherein a rock destruc-
tion tool 3 is convected Jo a shalt 1 and a drill pipe 4
is connected to a housing 2. the shalt 1 is centered in
the housing 2 by means ox radial bearings 5 which ensures
coaxial rotation ox the shalt 1 relative to an axis A
ox the turbine. Each stage oi the turbine comprises a sta-
tor 6 and a rotor 7 jig. 2).
In a turbodrill the system of the stators 6`(Figs.
1a and 1b) i8 iixed against turning relative to the housing
2 ahd the system ox the rotors 7 is mixed against turnip
relative to the shalt 1. In each stage the stator 6 (Fig. 3)
and the rotor 7 ore provided with respective rings 8 and
9, and also with respective spacing sleeves l and 11,
The ring 8 oi the stator 6 and the ring 9 ox the rotor 7
--8--
3~
are provided with the respective flow channels 12, 13
and also with hubs 14, 15 carrying bladings 16, 17 with
rims 18, 19 thereon.
A straight line S which i's parallel to the axis A of
ro-tation and passes in the interior ox the slow chann~:s
12, 13 ma be called an axis ox the flow. An arrow on ,he
axis S ox slow indicates the direction oi drilling fluid
movementO
From the two rings 8 and 9 (see, for example, jig. 5)
the ring is an upstream one relative to the ring 9,
while in relation to the ring 8 the rink 9 is a downstream.
During operation ox the turbine the rotation ox the
rotors 7 relative to the stators 6 is ensured by the pro-
vision ox axial and radial clearances 20, 21 respectively.
The bladings 16, 17 ox the stator 6 and the rotor 7 (Fix. 4)
are essentially sets of blades 22, 23 equally spaced in
the slow channels 129 13 (Fig. 3).
Profile ox the turbine blades 22, 23 (Fix. 4) is
usually characterized by a camber line 24, tangents 25 and
26 to the aamber live 24 at the exit and entry of the bla-
ding respeotivel~9 an angle ox curvature ox the chamber
line 24 and a angle between the tangent 25 and the
axis S ox slow.
Embodiment ox the flow channels 12, 13 (Fig 6) it
determined by configuration Or generating lines 27, 28,
2~, 30 ox surfaces of the hubs 14, 15 and the rims 18,
19 r'é'~pectively, forming the slow channels 12, 13 (same
reverence numbers denote identical elemen-ts).
_9_
33~
It is to be understood that there may be various em-
bodiments ox the turbine. However, irrespective ox a spe-
civic embodiment all the turbines, according to the in-
vention are made such that in a stage comprising at least
one bladin~ 16 (Figs. 3, I) the blades 23 ox which have
the angle oC ox curvature ox the camber line 24 treater
than the acute angle formed by the tangent 25 to the
camber line 24 at the exit of the blading 16 and the axis
S of drilling f luid slow, the ring with such a blading
is made with by-pass channels 33 arrangsd hydraulically
parallel to the flow channel 12 of the ring 8 and commu-
nicati~g the space between the ring 8 and-the upstream
ring 9 with -the space between the ring 8 and the downstream
ring 9 or discharging part ox the drilling fluid prom
the slow channel 12 ox the ring 8. The blading 16 is cha-
racterized by a enable hydraulia friction which depends
on the mode of turbine operation (rotational speed) and
is lower at a stalling mode and rises as the tuxbine gains
speed .
With the by-pass channels made in the Norm of annular
spaces 32 and 33 (jig. 7~ an increase in e~iective~ess
ox the turbine operation is attained also duo to.a substan-
tial decrease in losses ox the momen-t ox force caused by
friction in the drilling fluid containing the solid phase
and in wear ox the turbine In addition to the by-pass
channels made in the Norm ox the annular spaces 32 and 33,
an embodiment ox the turbine shown in jig. 7 is also cha-
~%;33~
racterized by the provision ox partial ovelappings o~the flow channel 13 on the side ox the by-pass channel 32
by the hub 14 and also the flow channel 12 on the side
ox the by-pass channel 33.by the hub 15.
he experimental investigations have proved that at a
ratio of a radial dimension l the annular space 33
between the spacing sleeve 11 ox the rotor 7 and the ring
8 of the stator 6 to an axial dimension h1 the ring 8
being in the range of 0.2 to 1.0, the most favorable con-
ditions are provided or regulation of the fluid flow
rate it -the stator 6 (Fig. 2)~ As to the rotor 7, such
conditions are provided at a ratio ox a radial dimension
2 f the annular space 32 to an axial dimension h2 of the
ring 9 being in the range of 0.14 to 0.5.
Absolute values ox d~1 and ~2 in real turbines made
according to the invention amount respectively to 2.2-
l mm and 1.6 - 5 mm which are substantially greater than
the values ox the radial clearances in the known hydraulic
turbine.
In order to ra-tio~ally utilize the overall diametrical
dimensions of a turbine which is especially essential for
turbines ox small diameters and also to i~tensiiy regula-
ton, it it preferable to make the b~-pass charnels 34 and
31 (Fig. 5) in the body of the hub 14 ox the stator 6 and
the hub 15 of the rotor 7.
It is desirable that a generating live, for example
27 (jig. 6), ox the suriace of the hub 14 forming the
flow channel 12 oi the ring 8 arranged upstream from
3~
the ring 9 with the by-pass channels 31 and 32 be inclined
from top to bottom on the side ox the by-pass channel ~2
at the exit in relation to the axis S of slow, The slow
channels 12, 13 of the rings 8, 9 made with such an incli-
nation of the generating lines 27, 28, 29, 30 of the sur-
race minimizes the leaks ox the drilling fluid past the
flow channels 13, ~2 at a stalling mode determi~i~g the
load pick-up characteristics ox the turbine.
For the same reason, it is preferable that the hub
14 and/or 15 (Figs. 6, 7) and the ring 18, 19 ox toe ring
8, 9 arranged upstream prom the ring 9, 8 with by-pass
charnels 32, 33, 31, 34 respectively should partially over-
lap the ilow channel 13, 21 on the side ox the by-pass
channel 32, 33, 31, 34 respecti~el~.
A hydraulic multistage turbine ox the invention ope-
rates in the hollowing way.
rom the surface the mud pumps deliver the drilling
fluid through the drill pipe 4 figs. 1a and 1b) to the
turb~drill. At a stalling mode the drilling fluid it the
amount delivered by the pump prom the surface passes out
ox the flow channel l ox- the rotor 7 (Fig. 3) with a
preset deviation of the slow acquired due to interaction
with the blading 17. Further the fluid passes in the ilow
channel 12 oi the stator 6. As at this mode ox operation
the hydraulic friction ox the blading 16 is at a minimum
the drilling fluid enters in the pull volume the slow
channel 12 ox the stator 6, wherein it acquire a respec-
~12-
tive deviation, Interaction of the drilling fluid withthe bladings 17 and 16 in the pull volume results in
providing a maximum moment oi force ox the turbine.
As the turbine gain speed the hydraulic iriction
ox the blading 16 increases due to which part of the
drilling fluid (up to 30~0 at a no-load running condition)
leaving the slow channel 13 goes in the by-pass channel
3~ past the blading 16. the remaining part of the dril-
ling fluid which passed through the blading 16 has a lower
speed which provides a respective decrease in the rota-
tional speed I the tuxbine. Thus the flow rate ox the dril-
fig fluid passing through the bladin~s is regulated
inside the turbine proper which brings about the required
reduction in the rotational speed, with the moment oY
force beins retained.
Due to reduction in the rotational speed up to
14~-200 rpm in an optimal altsrnative embodiment), the
use ox the turbine of the invention makes it possible
to improve durability ox the bits by 1.5-4.0 times anc
consequently to increase the iootage per bit by 1O3-3.
times when compared with the known turbinesO Greater
figures are provided by the use ox drilling bits with
oil-~illed sealed bearings.
In an alternative embodiment ox the turbine shown
in jig. 7, there is also provided a substantial decrease
~nLthe unfavorable lose ox the moment ox force caused
-13-
33S
by Iriction ox the rotor 7 in the drilling iluid contai-
ning the solid phase, with the result that durabiht~
of toe turbine is upgraded.
