FLOW PULSING DEVICE FOR A DRILLING MOTOR

DISPOSITIF DIMPULSIONS D'ECOULEMENT POUR MOTEUR DE FORAGE

English Abstract

A downhole flow pulsing device comprises a housing connected in series with a drill string and a valve with a rotating portion in the housing arranged to vary an area of a flow passage through the housing. A fluid actuated positive displacement motor drives rotation of the valve. A drive link permits the rotating portion of the valve to be optionally coupled directly to the motor of the drill string. The valve includes radially oriented rotating ports intermittently communicating with surrounding fixed ports and a bypass channel. Axial displacement of the rotating ports relative to the fixed ports and bypass channel permits amplitude of the downstream fluid pulses to be adjusted. The valve includes a number of circumferentially spaced ports which differs from a prescribed number of pressure fluctuations in the fluid for each full rotation of the rotor of the drill motor.

French Abstract

Un dispositif dimpulsions d'écoulement de fond de trou comprend un logement relié en série avec une colonne de forage et une soupape dotée dune portion en rotation dans le logement disposée pour faire varier une aire dun passage d'écoulement dans le logement. Un moteur à déplacement positif actionné par un fluide entraîne la rotation de la soupape. Un lien dentraînement permet à la portion en rotation de la soupape dêtre facultativement couplée directement au moteur de la colonne de forage. La soupape comprend des orifices de rotation orientés radialement communiquant de manière intermittente avec les orifices fixes avoisinants et un canal de dérivation. Le déplacement axial des orifices de rotation par rapport aux orifices fixes et au canal de dérivation permet l'ajustement de lamplitude des impulsions de fluide en aval. La soupape comprend plusieurs orifices espacés sur la circonférence qui diffèrent dun nombre prescrit de fluctuations de pression du fluide pour chaque rotation entière du rotor du moteur de forage.

Claims

18
CLAIMS:
1. A
downhole flow pulsing device in combination with a drill string
comprising a tubing string, a drilling motor having a stator housing connected
in series
with the tubing string and a rotor supported in the stator housing so as to be
arranged
to rotate relative to the stator housing and tubing string responsive to a
flow of
pressurized drilling fluid into the tubing string, a drill bit coupled to a
bottom end of the
rotor of the drilling motor so as to be arranged to rotate with the rotor of
the drilling
motor, and a rotor keeper, the downhole flow pulsing device comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatably
supported in the tubular housing so as to vary an area of the flow passage as
the
rotating portion rotates relative to the fixed portion;
a drive link member arranged to be connected between the rotating
portion of the valve and the rotor of the drilling motor so as to rotate the
rotating
portion of the valve relative to the tubing string together with the rotor of
the drilling
motor;
wherein the rotor keeper comprises an annular retainer member
mounted in series with the tubing string between the stator housing of the
drilling
motor and the tubular housing of the flow pulsing device and a keeper member
extending through the retainer member so as to be connected in series between
the
rotor of the drilling motor and the drive link member, the keeper member
including a

19
portion of enlarged dimension above the retainer member which cannot pass
through
the annular retainer member.
2. the device according to claim 1 wherein the rotating portion of the
valve is coupled to the rotor of the drilling motor by the drive link member
such that
only the drilling motor drives rotation of the rotating portion of the valve
relative to the
fixed portion of the valve.
3. The device according to claim 1 wherein the rotor is rotated
eccentrically within the stator housing and wherein the drive link member
comprises a
lower universal joint arranged for coupling a bottom end of the drive link
member to
the rotor and an upper universal joint arranged for coupling a top end of the
drive link
member to the rotating portion of the valve.
4. The device according to claim 1 wherein the rotating portion is
supported in an axially extending valve bore in the fixed portion so as to be
rotatable
about the longitudinal axis relative to the fixed portion, the fixed portion
comprising a
plurality of fixed ports at circumferentially spaced positions for
communication
between the valve bore and an annular space in the tubular housing about the
drive
link member therebelow and the rotating portion comprising a central bore
having a
top end arranged to receive drilling fluid from the tubing string and a
plurality of
rotating ports at circumferentially spaced positions extending radially
outward from the
central bore so as to be arranged to intermittently communicate with the fixed
ports as
the rotating portion of the valve is rotated.
5. The device accordingly to claim 4 wherein there is provided an
equal number of fixed ports and rotating ports.
6. The device according to claim 1 wherein the drill motor generates
a prescribed number of pressure fluctuations in the drilling fluid for each
full rotation of

20
the rotor within the stator housing and wherein the rotating portion comprises
a
plurality of rotating ports and the fixed portion comprises a plurality of
fixed ports
arranged to intermittently communicate with the rotating ports as the rotating
portion is
rotated relative to the fixed portion, the number of rotating ports and said
prescribed
number being different from one another such that the number of rotating ports
is not
evenly divisible into said prescribed number and said prescribed number is not
evenly
divisible into the number of rotating ports.
7. A
downhole flow pulsing device for use with a drill string
comprising a tubing string, a drilling motor having a stator housing connected
in series
with the tubing string and a rotor supported in the stator housing so as to be
arranged
to rotate relative to the stator housing and tubing string responsive to a
flow of
pressurized drilling fluid into the tubing string, and a drill bit coupled to
a bottom end of
the rotor of the drilling motor so as to be arranged to rotate with the rotor
of the drilling
motor, the downhole flow pulsing device comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatably
supported in the tubular housing so as to vary an area of the flow passage as
the
rotating portion rotates relative to the fixed portion; and
a drive link member arranged to be connected between the rotating
portion of the valve and the rotor of the drilling motor so as to rotate the
rotating
portion of the valve relative to the tubing string together with the rotor of
the drilling

21
motor; wherein the rotating portion comprises a plurality of rotating ports
and the fixed
portion comprises a plurality of fixed ports arranged to intermittently
communicate with
the rotating ports as the rotating portion is rotated relative to the fixed
portion and
wherein the fixed portion is adjustable in position in a direction of the
longitudinal axis
relative to the rotating portion so as to vary a maximum communication area
between
the fixed and rotating ports.
8. The device according to claim 7 in combination with the drill string
wherein the rotor is fixed in a longitudinal direction relative to the stator
housing by
rotor bearings and wherein the rotating portion is substantially fixed in the
direction of
the longitudinal axis relative to the tubular housing by the drive link member
connected between the rotating portion and the rotor of the drilling motor.
9. A downhole flow pulsing device for use with a drill string
comprising a tubing string, a drilling motor having a stator housing connected
in series
with the tubing string and a rotor supported in the stator housing so as to be
arranged
to rotate relative to the stator housing and tubing string responsive to a
flow of
pressurized drilling fluid into the tubing string, and a drill bit coupled to
a bottom end of
the rotor of the drilling motor so as to be arranged to rotate with the rotor
of the drilling
motor, the downhole flow pulsing device comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatably
supported in the tubular housing so as to vary an area of the flow passage as
the

22
rotating portion rotates relative to the fixed portion; and
a drive link member arranged to be connected between the rotating
portion of the valve and the rotor of the drilling motor so as to rotate the
rotating
portion of the valve relative to the tubing string together with the rotor of
the drilling
motor;
wherein the rotating portion is supported in an axially extending valve
bore in the fixed portion so as to be rotatable about the longitudinal axis
relative to the
fixed portion; the fixed portion comprising a plurality of fixed ports at
circumferentially
spaced positions for communication between the valve bore and an annular space
in
the tubular housing about the drive link member therebelow;
the rotating portion comprising a central bore having a top end arranged
to receive drilling fluid from the tubing string and a plurality of rotating
ports at
circumferentially spaced positions extending radially outward from the central
bore so
as to be arranged to intermittently communicate with the fixed ports as the
rotating
portion of the valve is rotated; and
the rotating portion being positioned relative to the fixed portion to define
a bypass area which remains in communication between the central bore of the
rotating portion and the annular space in the tubular housing below the valve
as the
rotating ports intermittently communicate with the fixed ports to define the
flow
passage which varies in area.
10. The device according to claim 9 wherein the bypass area and a
maximum communication area between the fixed and rotating ports are adjustable
simultaneously with one another.
11. The device according to claim 9 wherein the bypass area is
adjustable by displacing the fixed portion relative to the rotating portion in
a direction

23
of the longitudinal axis.
12. The device according to claim 11 wherein the fixed portion is
movable in the direction of the longitudinal axis relative to the tubular
housing
between a plurality of different set positions corresponding to different
bypass areas.
13. The device according to claim 12 wherein the fixed portion of the
valve is threadably received in the tubular housing such that a position of
the fixed
portion in the direction of the longitudinal axis is adjusted by rotating the
fixed portion
relative to the tubular housing about the longitudinal axis.
14. The device according to claim 12 wherein there is provided a set
screw arranged to retain the fixed portion in fixed relation to the tubular
housing in
each of the set positions.
15. A downhole flow pulsing device for use with a drill string
comprising a tubing string, a drilling motor having a stator housing connected
in series
with the tubing string and a rotor supported in the stator housing so as to be
arranged
to rotate relative to the stator housing and tubing string responsive to a
flow of
pressurized drilling fluid into the tubing string, and a drill bit coupled to
a bottom end of
the rotor of the drilling motor so as to be arranged to rotate with the rotor
of the drilling
motor, the downhole flow pulsing device comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatable
supported in the tubular housing so as to vary an area of the flow passage as
the

24
rotating portion rotates relative to the fixed portion; and
a drive link member arranged to be connected between the rotating
portion of the valve and the rotor of the drilling motor so as to rotate the
rotating
portion of the valve relative to the tubing string together with the rotor of
the drilling
motor;
wherein the rotating portion is supported in an axially extending valve
bore in the fixed portion so as to be rotatable about the longitudinal axis
relative to the
fixed portion;
the fixed portion comprising:
a plurality of fixed ports at circumferentially spaced positions for
communication between the valve bore and an annular space in the tubular
housing
about the drive link member therebelow; and
a bypass channel extending about a full circumference of the
valve bore below the fixed ports and in communication with said annular space;
and
the rotating portion comprising a central bore having a top end arranged
to receive drilling fluid from the tubing string and a plurality of rotating
ports at
circumferentially spaced positions extending radially outward from the central
bore so
as to be arranged both to intermittently communicate with the fixed ports as
the
rotating portion of the valve is rotated and to communicate with the bypass
channel
therebelow.
16. The device according to claim 15 wherein a ratio between
communication of the rotating ports with the bypass channel and communication
of
the rotating ports with the fixed ports is adjustable by displacing the fixed
portion
relative to the rotating portion in a direction of the longitudinal axis.
17. A downhole flow pulsing device for use with a tubing string

25
arranged to receive a flow of pressurized drilling fluid therethrough, the
device
comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatably
supported in the tubular housing so as to vary an area of the flow passage as
the
rotating portion rotates relative to the fixed portion;
a fluid actuated positive displacement motor arranged to drive rotation of
the rotating portion of the valve responsive to the flow of pressurized
drilling fluid in
the tubing string;
the rotating portion of the valve being supported in an axially extending
valve bore in the fixed portion so as to be rotatable about the longitudinal
axis relative
to the fixed portion;
the fixed portion comprising a plurality of fixed ports at circumferentially
spaced positions for communication between the valve bore and an annular space
in
the tubular housing about the drive link member therebelow;
the rotating portion comprising a central bore having a top end arranged
to receive drilling fluid from the tubing string and a plurality of rotating
ports at
circumferentially spaced positions extending radially outward from the central
bore so
as to be arranged to intermittently communicate with the fixed ports as the
rotating
portion of the valve is rotated;
the rotating portion being positioned relative to the fixed portion to define

26
a bypass area which remains in communication between the central bore of the
rotating portion and the annular space in the tubular housing below the valve
as the
rotating ports intermittently communicate with the fixed ports; and
the bypass area being adjustable by displacing the fixed portion relative
to the rotating portion in a direction of the longitudinal axis.
18. The
device according to claim 17 wherein a position of the
rotation portion is fixed in the direction of the longitudinal axis relative
to the tubular
housing by suitable bearings and wherein the fixed portion is movable in the
direction
of the longitudinal axis relative to the tubular housing between a plurality
of different
set positions corresponding to different bypass areas.

Description

CA 02680895 2009-09-30
FLOW PULSING DEVICE FOR A DRILLING MOTOR
FIELD OF THE INVENTION
The present invention relates to a flow pulsing device arranged to pulse
drilling fluid of a drilling motor in a drilling string.
BACKGROUND
When drilling an oil or gas production well using a drill string, it is
common to encounter static friction that limits advancement of the drill
string into the
bore being formed. In these instances it is known to be desirable to pulse the
flow of
drilling fluid pumped through the drill string to vibrate the drill and reduce
the static
friction so that deeper wells can be more readily produced. Examples of prior
United
States Patents relating to pulsing the flow of drilling fluid include
6,279,670 by
Eddison et al; 4,819,745 by Walter; and 2,743,083 by Zublin.
In Zublin, US 2,743,083, various embodiments are disclosed in which a
rotating valve component is driven to rotate by suitable vanes coupled thereto
or by
the orientation of the flow passages therethrough. As the rotating valve
component is
directly driven by vanes coupled thereto, the amount of pulse capable is
limited.
Furthermore in some embodiments a bypass area is provided, however the bypass
area is proportionally very large compared to the pulsing component so as to
further
limit the amount of pulsing possible.
Walter, US 4,819,745, discloses a further example of a flow pulsing
device in which the rotating component of the valve creating the pulses is
driven by an
impeller with vanes integrally associated therewith so that the overall
structure of the
integrated valve and impeller is very complex and can therefore have problems
with
reliability. The direct coupling of the impeller with the rotating valve
component may
also limit the amount of pulsing possible.

CA 02680895 2009-09-30
2
Eddison, US 6,279,670, discloses another example of a flow pulsing
apparatus in which a dedicated motor comprising a rotator rotating within a
stator is
required to be provided separate from the drilling motor just for driving the
valve
component. The overall assembly of a flow pulsing valve together with a motor
operated solely for rotating the valve is a costly and complex structure to be
installed
in a drill string separate from the drilling motor.
SUMMARY OF THE INVENTION
According to one aspect of the invention there is provided a downhole
flow pulsing device for use with a drill string comprising a tubing string, a
drilling motor
having a stator housing connected in series with the tubing string and a rotor
supported in the stator housing so as to be arranged to rotate relative to the
stator
housing and tubing string responsive to a flow of pressurized drilling fluid
into the
tubing string, and a drill bit coupled to a bottom end of the rotor of the
drilling motor so
as to be arranged to rotate with the rotor of the drilling motor, the downhole
flow
pulsing device comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatably
supported in the tubular housing so as to vary an area of the flow passage as
the
rotating portion rotates relative to the fixed portion;
a drive link member arranged to be connected between the rotating
portion of the valve and the rotor of the drilling motor so as to rotate the
rotating

CA 02680895 2009-09-30
3
portion of the valve relative to the tubing string together with the rotor of
the drilling
motor.
By providing a valve with a drive link member connected thereto which
permits connection of the valve directly to the drilling motor, the flow
pulsing device is
simple in construction having a minimum number of components which can be
installed at any point in the drill string above the drilling motor. The
direct coupling of
the flow pulsing valve to the rotor permits the valve to be maintained in a
reliable
manner out of synchronicity with the natural vibration of the drilling motor
to maximize
the amplitude of the vibrations produced with a simple reliable structure.
According to a second aspect of the present invention there is provided
a downhole flow pulsing device for use with a tubing string arranged to
receive a flow
of pressurized drilling fluid therethrough, the device comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatably
supported in the tubular housing so as to vary an area of the flow passage as
the
rotating portion rotates relative to the fixed portion;
a fluid actuated positive displacement motor arranged to drive rotation o
the rotating portion of the valve responsive to the flow of pressurized
drilling fluid in
the tubing string;
the rotating portion of the valve being supported in an axially extending
valve bore in the fixed portion so as to be rotatable about the longitudinal
axis relative

CA 02680895 2009-09-30
4
to the fixed portion;
the fixed portion comprising a plurality of fixed ports at circumferentially
spaced positions for communication between the valve bore and an annular space
in
the tubular housing about the drive link member therebelow;
the rotating portion comprising a central bore having a top end arranged
to receive drilling fluid from the tubing string and a plurality of rotating
ports at
circumferentially spaced positions extending radially outward from the central
bore so
as to be arranged to intermittently communicate with the fixed ports as the
rotating
portion of the valve is rotated;
the rotating portion being positioned relative to the fixed portion to define
a bypass area which remains in communication between the central bore of the
rotating portion and the annular space in the tubular housing below the valve
as the
rotating ports intermittently communicate with the fixed ports; and
the bypass area being adjustable by displacing the fixed portion relative
to the rotating portion in a direction of the longitudinal axis.
By further providing a fixed valve portion which is adjustable in a
longitudinal direction relative to a rotating component of the valve, an
amount of fluid
which bypasses the valve relative to the intermittent flow passage of the
valve allows
the amplitude of the vibration to be readily adjusted in the field unlike
prior devices.
According to a further aspect of the present invention there is provided a
downhole flow pulsing device for use with a tubing string arranged to receive
a flow of
pressurized drilling fluid therethrough, the device comprising:
a tubular housing arranged to be connected in series with the tubing
string, the housing having an axial bore extending along a longitudinal axis
therethrough so as to be arranged to permit passage of the drilling fluid
therethrough;

CA 02680895 2009-09-30
a valve supported in the bore of the tubular housing and defining a flow
passage arranged to receive the drilling fluid therethrough, the valve
comprising a
fixed portion in fixed relation to the tubular housing and a rotating portion
rotatably
supported in the tubular housing so as to vary an area of the flow passage as
the
5 rotating portion rotates relative to the fixed portion; and
a fluid actuated positive displacement motor comprising a stator housing
arranged to be connected in series with the tubing string and a rotor which is
rotatable
within the stator housing and connected to the rotating portion of the valve
so as to be
arranged to drive rotation of the rotating portion of the valve responsive to
the flow of
pressurized drilling fluid in the tubing string;
the motor being arranged to generate a prescribed number of pressure
fluctuations in the drilling fluid for each full rotation of the rotor within
the stator
housing;
wherein the rotating portion of the valve comprises a plurality of rotating
ports and the fixed portion comprises a plurality of fixed ports arranged to
intermittently communicate with the rotating ports as the rotating portion is
rotated
relative to the fixed portion;
the number of rotating ports and said prescribed number being different
from one another.
One embodiment of the invention will now be described in conjunction
with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic representation of a drill string.
Figure 2 is a sectional elevational view of the downhole flow pulsing
device in the drill string of Figure 1.

CA 02680895 2009-09-30
6
Figure 3 is an enlarged sectional view of the valve of the flow pulsing
device in an open position of the valve.
Figure 4 is a cross sectional view of the valve similar to Figure 3, but in
a closed position of the valve.
Figure 5 and Figure 6 are sectional views along the line A-A of Figure 3
in the open and closed positions of the valve respectively.
Figure 7 and Figure 8 are cross sectional views along the line A-A of
Figure 3 according to an alternative embodiment of the flow pulsing device in
the
open position and closed position respectively.
In the drawings like characters of reference indicate corresponding parts
in the different figures.
DETAILED DESCRIPTION
Referring to the accompanying figures there is illustrated a flow pulsing
device generally indicated by reference numeral 10. The device 10 is
particularly
suited for use with a drill string 12 of the type connected to the bottom end
of a tubing
string 14 in a well bore being formed.
The drill string comprises a drill motor 16 coupled to the bottom end of
the tubing string which further comprises a stator housing 18 connected in
series to
the tubing string 14 and a rotor 20 rotatably received within the stator
housing. The
stator housing and the rotor have complimentary lobes to force to rotation of
the rotor
20 relative to the stator housing responsive to a flow of drilling fluid
pumped into the
drill motor from the tubing string 14. The drill motor 16 thus comprises a
progressive
cavity positive displacement motor which rotates a drill bit 22 of the drill
string which is
coupled to rotate with the rotor 20 at the bottom end thereof. Suitable rotor
bearings
are provided in the drill motor to fix the position of the rotor relative to
the stator in the

CA 02680895 2009-09-30
7
longitudinal direction.
In operation the drilling fluid is pumped downwardly through the tubing
string into the top end of the stator housing such that the configuration of
the lobes of
the stator housing and rotor results in rotation of the rotor. The
configuration of the
lobes results in a prescribed number of fluid pressure fluctuations in the
drilling fluid
pumped through the stator housing for each full rotation of the rotor relative
to the
housing. The configuration of the rotor within the housing results in an
eccentric
rotation of the top end of the rotor about an upright longitudinal axis of the
housing.
In the illustrated embodiment, a rotor keeper 24 is provided for
connection between the top end of the drill motor and the tubing string. The
rotor
keeper 24 is received in an upper portion 26 of the stator housing comprising
a
tubular extension extending in the longitudinal direction upwardly beyond the
end of
the rotor 20 and the lobes within the stator housing 18. The upper portion 26
includes
a female connecting portion at the top end thereof. The connecting portion 28
generally comprises a counter bore in the end of the tubular upper portion of
increased internal diameter which is internally threaded and terminates at an
internal
shoulder against which the bottom end of the remainder of the tubing string
thereabove is connected.
The rotor keeper 14 generally comprises an annular retainer member 30
which is annular in shape and which is similar in outer diameter to the
counter bore
forming the connecting portion 28 at the end of the upper portion so that the
retainer
member 30 can be received within the connecting portion 28 in abutment with
the
shoulder at the inner end thereof. An internal diameter of a central opening
in the
retainer member 30 is smaller than the internal diameter of the upper portion
of the
stator housing and the tubing string thereabove.

CA 02680895 2009-09-30
8
The rotor keeper 24 further comprises a keeper member 32 in the form
of an elongate shaft which is only slightly longer than the upper portion of
the stator
housing projecting upwardly beyond the rotor. The keeper member 32 is mounted
in
fixed connection to the top end of the rotor 20 at the bottom end thereof such
that the
rotor and the keeper member are eccentrically rotated together about the
longitudinal
axis of the stator housing. The diameter of the shaft forming the keeper
member is
smaller than the diameter of the central opening in the retainer member
through which
it is received to allow the eccentric rotation of the shaft relative to the
surrounding
retainer member. The top end of the keeper member is enlarged in diameter in a
lateral dimension relative to the central portion of the keeper member which
extends
through the retainer member 30 such that the top end of the keeper member is
larger
in diameter than the interior diameter of the central opening in the retainer
member 30
to prevent passage of the top end of the keeper member downwardly through the
retainer member 30. In this instance, in the result of any failure of the
rotor relative to
the stator housing, the rotor is prevented from falling downwardly through the
stator
housing by the top end being retained by the rotor keeper relative to the top
end of the
stator housing.
The device 10 generally comprises a tubular housing 34 arranged to be
connected in series between the tubing string 14 thereabove and the drill
string 12
therebelow. The tubular housing 34 is generally cylindrical and elongate in a
direction
of a longitudinal axis of the tubing string. An axial bore 36 extends in the
direction of a
longitudinal axis of the housing from the top end to the bottom end through
the
housing. The bottom end 38 of the housing includes a male connecting portion
arranged to be threadably received into the female connecting portion at the
top end
of the stator housing. The opposing top end 40 includes a connecting portion
in the

CA 02680895 2009-09-30
9
form of a female connector having an internally threaded counter bore for
threaded
connection to the bottom end of the tubing string thereabove.
The tubular housing 34 between the threaded top and bottom ends is
divided into an upper portion 42 adjacent the top end and a lower portion 44
which
spans the majority of the length of the housing below the upper portion. The
lower
portion has a cylindrical constant diameter inner surface which is greater in
diameter
than the upper portion 42 thereabove. The upper portion 42 adjacent the
connecting
portion at the top end is reduced in internal diameter as compared to the
connecting
portion thereabove and as compared to the lower portion 44 therebelow. A
central
portion of the upper portion 42 is internally threaded for mounting the flow
pulsing
valve 46 of the device therein.
The flow pulsing valve 46 comprises a fixed portion 48 threadably
mounted into the threaded portion of the upper portion 42 of the housing so as
to be
substantially fixed in orientation relative to the tubular housing in
operation. The valve
46 further comprises a rotating portion 50 which is rotatably supported within
the fixed
portion 48 for rotation about a longitudinal axis of the tubular housing
relative to the
fixed portion as well as being supported for longitudinal sliding movement
relative to
the fixed portion in the direction of the longitudinal axis.
The fixed portion 48 comprises a collar having a generally cylindrical
body with an outer diameter which fits within the upper portion 42 of the
axial bore
through the housing 34. External threads on the fixed portion 48 permit the
threaded
connection between the fixed portion 48 of the valve and the surrounding upper
portion of the housing 34. Due to the threaded connection therebetween,
rotation of
the fixed portion 48 about the longitudinal axis of the housing in relation to
the housing
controls the position of the fixed portion 48 in the direction of the
longitudinal axis

CA 02680895 2009-09-30
relative to the housing.
A plurality of set screws 52 are received within respective mounting
apertures through the cylindrical wall of the housing 34 for frictional
engagement with
the peripheral wall of the fixed portion 48 when the set screws are tightened
to retain
5 the axial position of the fixed portion 48 at any one of a plurality of
different positions
in the longitudinal direction relative to the tubular housing corresponding to
different
operating positions of the flow pulsing valve 46.
An upper end of the collar forming the fixed portion 48 includes a flange
portion having a radial dimension similar to the threads therebelow for
mounting a
10 suitable 0-ring annular sealing member in an annular groove therein
which provides
sealing engagement between the outer surface of the fixed portion 48 of the
valve and
the surrounding inner surface of the axial bore of the tubular housing.
Adjacent a
bottom end of the upper portion 42 of the housing there is provided an annular
formation with an annular groove therein for locating an 0-ring annular
sealing
member therein which is engaged between the outer surface of the fixed portion
48 of
the valve and the surrounding inner surface of the tubular housing 34 below
the
threaded connection therebetween. Accordingly there is provided one of the 0-
rings
54 in engagement between the fixed potion 48 of the valve and the surrounding
tubular housing at locations both above and below the threaded connection
therebetween. Any flow of drilling fluid is thus directed through a valve bore
56
extending axially through the body forming the fixed portion 48 of the valve.
The valve bore 56 is open through the top end through a suitable central
opening in the top of the body forming the fixed portion 48 such that fluid
pumped
down through the tubing string is communicated into the valve bore 56 through
the top
opening 58. The top opening 58 is non-circular in cross section for mating
with a

CA 02680895 2009-09-30
11
suitable tool to selectively drive rotation of the fixed portion 48 relative
to the
surrounding tubular housing 34 when varying the operating position of the
valve.
The bottom end of the fixed portion 48 protrudes downwardly beyond
the upper portion 42 of the surrounding housing into the lower portion 44 of
increased
internal diameter so as to define an annular space 60 about the bottom end of
the
body forming the fixed portion 48 of the valve between the fixed portion and
the
surrounding inner surface of the lower portion 44 of the housing 34.
The body forming the fixed portion 48 of the valve further comprises a
plurality of fixed ports 62 which are provided at circumferentially spaced
positions
about the longitudinal axis in which each fixed port extends radially outward
for
communication between the valve bore 56 and the surrounding annular space 60.
Each of the fixed ports is also open through to the bottom end of the body
forming the
fixed portion 48.
The body forming the fixed portion 48 also includes a bypass channel 64
formed adjacent the bottom end along the inner surface of the valve bore 56.
More
particularly the bypass channel 64 comprises an annular groove open to the
inner
surface of the valve bore and to the bottom end of the body forming the fixed
portion
48 of the valve. The bypass channel 64 is thus located to be connected in the
circumferential direction between all of the fixed ports 62. The dimension of
the
bypass channel 64 is such that the channel is much shorter in length in the
direction
of the longitudinal axis than the fixed ports in communication therewith
thereabove,
such that an overall area of the bypass channel 64 in communication with the
valve
bore is much smaller than the communication of the area of the fixed ports
with the
valve bore.
The rotating portion 50 of the valve 46 similarly comprises a generally

CA 02680895 2009-09-30
12
cylindrical body in the form of a sleeve which is mounted in the valve bore so
that the
outer diameter of the rotating portion 50 is close in dimension to the inner
diameter of
the valve bore. The rotating portion 50 is supported within the surrounding
fixed
portion 48 such that the rotating portion is both slidable in the longitudinal
direction of
the longitudinal axis of the housing as well as being rotatable about the
longitudinal
axis in relation to the fixed portion 48.
The rotating portion includes a central bore 66 extending axially
therethrough from an open top end receiving fluid from the central opening 58
in the
top of the fixed portion. The internal diameter of the central bore 56 is near
in
dimension to the internal diameter of the top opening 58 in the fixed portion.
The
bottom end of the central bore 56 terminates at a bottom wall 68 where the
flow of
drilling fluid is diverted generally radially outward from the central bore 66
through
respective rotating ports 70 near in elevation to the fixed ports 62 in the
surrounding
fixed portion 48. The number of rotating ports 70 is identical to the number
of fixed
ports with both sets of ports being spaced evenly in the circumferential
direction about
the longitudinal axis. The rotating ports 70 are sloped downwardly and
radially
outward from the central bore to respective outer ends which are arranged to
communicate with the bypass channel 64 and the fixed ports 62 respectively.
Under normal operation, the height of the outlet side of the rotating ports
70 is set to typically overlap both the elevation of the fixed ports and the
elevation of
the bypass channel therebelow. Fluid diverted downwardly through the valve
from the
tubing string is thus directed through the central bore 66 to the rotating
ports to be
subsequently directed in a constant manner to the bypass channel overlapping
the
bottom portion of the rotating ports. Simultaneously, rotation of the rotating
portion
relative to the fixed portion causes the upper portions of the rotating ports
to be

CA 02680895 2009-09-30
13
aligned with the fixed ports only at regular intervals so that the
communication is
intermittent through the ports. In this manner a small portion of fluid is
permitted to
continuously flow from the rotating ports to the bypass channel while the
larger portion
of the flow is directed intermittently through the fixed ports to produce
surges in the
pressure of drilling fluid downstream from the valve when the valve is rotated
in
operation.
The rotating portion of the valve is typically fixed in the longitudinal
direction of the longitudinal axis relative to the surrounding tubular housing
by
connection of the rotating portion of the valve to the rotor of the drilling
motor as
described in further detail below. Accordingly by adjusting the position of
the fixed
portion of the housing in the longitudinal direction of the longitudinal axis,
the ratio of
the portion of the rotating ports which overlap the fixed ports intermittently
in
communication therewith versus the amount of overlap of the rotating ports
with the
bypass channel in communication therewith is adjusted.
The longitudinal positioning of the fixed portion thus has an effect on the
maximum communication area of the rotating ports with the fixed ports at the
portion
of rotation where they are fully in alignment with one another. Rotation of
the rotating
portion of the valve relative to the surrounding fixed portion causes the flow
area
through the valve to be varied from the maximum communication when the ports
are
in alignment with one another in the open position of Figures 3, 5 and 7 to a
minimum
communication area corresponding to only communication of fluid through the
bypass
channel when the ports are in not aligned with one another in a closed
position shown
in figures 4, 6 and 8. The flow passage area through the valve thus
corresponds to
the area of communication between the central bore in the rotating portion of
the
valve and the surrounding annular space in the tubular housing between the
valve

CA 02680895 2009-09-30
14
and the surrounding lower portion of the tubular housing spaced outwardly
therefrom.
When adjusting the fixed portion between different set positions thereof
relative to the surrounding tubular housing, the result of adjusting the
maximum
communication area between the rotating ports and the fixed ports as well as
the
bypass area of communication between the rotating ports and the bypass
channel, is
that the resulting amplitude of the fluid pulses downstream from the valve is
adjusted.
Rotation of the fixed portion of the housing relative to the tubular housing
causes its
longitudinal position to be adjusted for simultaneously adjusting the maximum
communication area between the ports and the communication with the bypass
area.
The rotating portion of the valve is coupled to the rotor of the drill motor
therebelow by a drive link member 72 which comprises an elongate shaft
extending
generally in the direction of the longitudinal axis. The upper end of the
drive link
member is coupled by an upper universal joint 74 directly to the body of the
rotating
portion of the valve while a lower universal joint 76 couples the bottom end
of the
drive link member to the top end of the rotor keeper member 32.
Each of the universal joints 74 and 76 comprises an elongate body
having a threaded socket 78 at an outer end thereof comprising a female
connection
for threaded connection to a correspond male connector 80 on the bottom end of
the
rotating portion of the valve or on the top end of the shaft of the rotor
keeper member
32 respectively. The opposing inner end of each universal joint includes a
suitable
socket 82 at the inner which receives a respective one of the ends of the
shaft of the
drive link member therein.
The ends of the shaft as well as the sockets 82 have a suitable mating
cross section which is either splined or polygonal for example so that the
shafts and
the bodies forming the universal joints above and below the shaft are all
arranged to

CA 02680895 2009-09-30
rotate together; however, the ends of the shaft are rounded in profile to
allow so side
to side rocking motion of the shaft relative to each of the bodies forming the
universal
joints 74 and 76. The rounded profile at the ends of the shaft correspond to
an end
portion 84 of enlarged dimension received within the socket 82 and retained
therein
5 by a suitable retainer 86 which is annular about the shaft. The retainer 86
has an
inner diameter which is smaller than the internal diameter of the enlarged
ends of the
shaft such that threading the retainer into the respective socket 82 permits
the
enlarged ends of the shaft to be retained in the axial direction within the
respective
bodies forming the universal joints.
10 The connections of the universal joints are such that the position
of the
rotating portion of the valve in the longitudinal direction is fixed by the
drive link
member 72 to the rotor of the drill motor which is in turn fixed relative to
the
surrounding housing thereof by suitable bearings of the drill motor coupled
between
the rotor and surrounding stator housing. The universal joints permit the body
of the
15 lower universal joint 76 to follow the eccentric rotation of the
rotor keeper and drill
motor rotor to which it is coupled while the body of the upper universal joint
rotates
concentrically with the longitudinal axis of the rotating portion of the valve
thereabove.
The drive link member 72 thus translates the rotation of the rotor to rotation
of the
rotating portion of the valve relative to the surrounding housing despite the
rotor
rotating eccentrically relative to the longitudinal axis and the rotating
portion of the
valve rotating concentrically about the longitudinal axis.
As shown in figures 1 through 6, according to a first embodiment for four
rotating ports are provided at equally spaced positions in the circumferential
direction
for communication with four similarly equally circumferentially spaced ports
in the
fixed portion of the valve. By arranging the number of ports in the valve to
specifically

CA 02680895 2009-09-30
16
not match the natural frequency of the drill motor to which it is coupled, the
amplitude
of fluid pressure pulses downstream of the valve and the resulting amplitude
of
vibration of the drill string can be maximized. Specifically the number of
ports is
selected to be mismatched with the prescribed number of fluid pressure
fluctuations
per full rotation of the drill rotor relative to the stator housing. The
embodiment of
figures 1 through 6 is thus well suited for a drill motor having lobes on the
rotor and
stator housing which naturally produce 3, 5 or 6 or any multiple thereof, of
fluid
pressure fluctuations per rotation of the motor.
According to a further embodiment of figures 7 and 8, the number of
fixed ports and rotating ports are both 3 which are again equally
circumferentially
spaced about the longitudinal axis. A valve of this configuration is
particularly well
suited for a drill motor having lobes configured to produce 2, 4, or 5
pressure
fluctuations per rotation or any multiple thereof. In each instance the number
ports is
not evenly divisible into the prescribed number of pressure fluctuations per
rotation of
the motor nor is the prescribed number of pressure fluctuations per rotation
of the
motor evenly divisible into the number or ports.
In operation, the flow pulsing valve is typically mounted in the tubing
string above the drill motor in sufficiently close proximity to permit the
rotating portion
of the valve to be readily connected directly to the existing rotor of the
drill motor
rather than employing any other additional motor to drive the rotation of the
valve. By
varying the number of ports when selecting a flow pulsing device for a
particular drill
motor, the user can maximize the vibrations produced in a reliable and
consistent
manner as the rotation of the flow pulsing valve is always matched to be out
of
synchronicity to the rotation of the rotor of the drill motor. By further
providing an
adjustment in the longitudinal direction of the alignment of fixed and
rotating ports

CA 02680895 2016-02-24
17
oriented in a radial direction, the ratio of fluid which is forced into
intermittent
communication with the fixed ports versus constant communication with the
bypass
channel permits a ready adjustment of the amplitude of the vibrations produced
in a
manner which can be readily adjusted in the field. Adjustment requires merely
loosening the set screws and varying the threaded connection between the fixed
portion of the valve and the surrounding tubular housing. The direct
connection of the
rotating component of the valve with the rotor of the drilling motor which is
constrained
in the longitudinal direction by suitable bearings further ensures that the
components
of the valve cannot be misaligned from their set position by a simple back
pressure or
back flow of drilling fluid up the tubing string as can occur in some prior
art devices.
Since various modifications can be made in my invention as herein
above described, and many apparently widely different embodiments of same, it
is
intended that all matter contained in the accompanying specification shall be
interpreted as illustrative only and not in a limiting sense.

Representative Drawing