Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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R. R. VANN ~
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BACKGROUND OF THE INVENTION
In the art of well completion and well servicing, it is
often necessary to run small tubular goods thousands of feet down-
hole into a borehole, and to subse~uently retrieve the tubular
element. The pressure differential effected between ambient and
the production tubing of an oil well presents a piston effect which
continually drives the tubular element uphole with considerable
force. Sometimes the pressure differential is enormous. Accord-
ingly, when the tubular element is subjected to very high pressure
differentials, the tubing is forced upwards respective to the
lubricator with a proportional force. This piston action causes
considerable difficulty when various different packages must be
lowered through the tubing string to the bottom of the borehole.
For example, it is often desirable to lower an instrument
package to the bottom of the borehole in order to monitor the
temperature and pressure. At other times, it is desirable to
directly measure the bottom pressure of the wellbore by lowering
one end of a small diame-ter tubing down to the production forma-
tion. The pressure differential across the wellhead of a wellbore
causes the introduction of a tubular element in-to the well to be
analogous to one trying to push a rope or a long noodle, as opposed
to pulling the rope.
It would therefore be desirable to have made available
apparatus wh;ch can be attached to a wellhead in order to provide
a downward thrust on a tubular element, and thereby oyercome the
piston effect brought about by the wellbore pressure differential.
Such an apparatus is the subject of the present invention.
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R. R. VANN
SUMMARY OF THE INVENTION
Apparatus for forcing small tubular elements, such as wire-
lines and small diameter tubings, into and out of boreholes. The
apparatus comprises a lubricator connected to a sub. The sub
is removably affixed to the upper end of a cased wellbore. An
axi~l passageway is formed through the lubricator and sub. Annular
seal means are provided in the upper marginal end of the passageway,
so that a small tubular element is sealingly received by the
apparatus when moved axially through the passageway.
A pair of roller means have confronting outer peripheral
surfaces, and are placed in underlying relationship respective to
the seal means. The roller means have axially aligned shafts
arranged horizontally respective to one another which disposes the
shafts normal respective to the axial passageway. The rollers
drivingly engage one another and receive the tubular element more
or less tangentially through a mid-portion of -the two confronting
faces of the rollers.
Motor means are connected to drive the rollers in a contra-
rotating direction so that the motor turns in one direction to
drive the tubing downhole 7 and in a reverse direction to drive the
-tubing back uphole, thereby stripping the tubing through the seal
means and overcoming the piston effect brought about by the pres-
sure differential across the well.
In another embodiment of the invention, the rollers are in
the form of an oval track. The track is comprised of an endless
belt supported by spaced wheels, with there being confronting belt~
surfaces, and with the tubing being received in compressed relation-
ship therebetween.
The present apparatus is useful in running capillary tubing,
wirelines, and slick lines into and out of boreholes.
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R. R. VANN .
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Accordingly, a primary object of the present invention is
the provision o~ a means for overcoming the upthrust of tubular
elements which must be forced downhole into a high pressure well-
bore.
Another object of the present invention is the provision
of apparatus for sealingly receiving a tubular element there-
through, and forcing the tubular element into and out of a wellbore.
A further object of the present invention is to provide a
combination of a wellbore and a small diameter tubing along with
apparatus for forcing the tubing to move downhole and controlling
the uphole movemen-t in a wellbore.
Another and still further object of the present invention
is the provision of a sub assembly which sealingly receives a
small diameter tubing therethrough and forces the tubing to move
uphole and downhole against the pressure differential of the well.
These and various other objects and advantages of the in-
vention wîll become readily apparent to those skilled in the art
upon reading the following detailed description and claims and by
referring to the accompanying drawings.
The above objects are attained in accordance with the pre-
sent in~ention by the provision of a combination of elements which
are fabricated in a manner substantially as described in the above
abstract and SUJnmary,
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R. R. VANN
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a part diagrammatical, part schematical, part
cross-sectional~ broken view of a wellbore having apparatus made
in accordance with the present invention incorporated therewith;
Figure 2 is an enlarged, part cross-sectional view taken
along line 2-2 of Figure l;
Figure 3 represents a different side elevational view of
the apparatus disclosed in Figure 2, with some parts being removed
therefrom;
Figure 4 is a cross-sec-tional view taken along line 4-4 of
Figure 3;
Figure 5 is a cross-sectional view taken along line 5-5 of
Figure 3;
Figure 6 is a broken, schematical representation of a side
elevational view o~ another embodiMent of the present inven-tion;
and,
Figure 7 is another view of the apparatus disclosed in
Figure 6.
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R. R. VA~N .
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DETAILED DESCRIPTION ~F THE PREFERRED E~BO~IMENT
In Figure 1 of the drawings, there is disclosed a cased
borehole 10. A sub 12, made in accordance with the present inven-
tion, is removably affixed to the upper end of the casing. The
sub includes a lubricator 14 attached at the upper end thereof and
within which there is sealingly received a small diameter tubular
ele~ent 16, specifically a capillary tube.
The tube 16 is continuously wound about a drum 18 which is
suitably supported in aligned relationship respective to the longi-
tudinal axial centerline of the wellbore. The drum preferably is
of a large enough diame-ter to avoid deformably bending the small
tubing.
A tubing string 20 is concentrically arranged within the
casing and extends from the wellhead downhole adjacent to a hydro-
carbon containing formation 22. ~ gun firing device 23 is attached
to the lower end of the tube 16. The device 23 could equally well
be an instrunlent package, as will be more fully discussed later on
in this disclosure. A casing perforating gun 24 has a gun firing
head 26 arranged at the upper end thereof which can be ac-tuated by
device 23 to cause the illustrated shaped charges of the gun to be
discharged. A vent assembly 28 underlies a packer 29.
The wellhead includes outlets 30 and 32, respectively,
which are connected to the casing annulus and the production tubing,
respectively. A measuring and recording ins-trument 34 is connected
to receive a rate of flow signal from flow meter 36 and a pressure
signal from flow line 42. Pressure regulator 38 is connected to a
source of fluid pressure 40, and provides a cons-tant pressure at
39.
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R. R. VANN -.
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Flow line 43 provides a signal for the recorder. Swivel
46 is connected to flow line 45 and to the uppermost end of capil-
lary 16 so that fluid flow from 40 can be measured as it flows
downhole to the outlet end thereof.
As seen illustrated in Figure 2, the lubricator includes a
plurality of annular seals 48 which are positioned within the upper
marginal end of the sub assembly. An axial passageway 50 extends
through the seals for sealingly receiving the small diameter cylin-
drical tubing 16 therethrough. Confronting rollers 52 and 54 are
preferably made of resilient material so that the rollers can abut-
tingly engage one another in a driving manner as they contra-rotate,
with the tubing being located in captured relationship there-
between.
As seen in Figures 2-5, and in particular Figure 4, the
rollers are connected to shafts 56 and 58. Motor 60 drives roller
52, which engages roller 54 with great friction, so that the two
rollers concurrently counter-rotate,
Nu~neral 62 in Figure 3 indicates an inlet and outlet for
air, gas, electrical power, or hydraulic fluid by which the motor
60 can be operated.
In the embodiment seen in ~igures 6 and 7, an endless track
64 is disposed between spaced rollers 66 and 68. A confronting
endless belt 70 is likewise disposed between spaced rollers 72 and
74, with there being the tubing 16 received in captured relation-
ship between the confronting belt faces at 76.
A right angle gear box 78 is driven by gas motor 80. A gas
supply 82 flows into and out of the motor, thereby imparting rota-
tional mo-tion into the spaced apart rollers, The rollers are
~ounted to shafts 84 and 86, Numeral 88 is a ported outlet pipe
which mechanically connects the capillary 16 to the package 23, and
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which allows fluid flow out of the ports 90.
In operation, the sub assembly, which includes the sub 12
along with the lubricator 14, is removably moun~ed to the top of
the cased borehole. The drum 18 is supported in aligned relation-
ship respective to the -tubing string. The val~e 92 is closed, the
sub is attached to the wellhead, the lubricator is lifted from the
sub 12, the tubing or elongated member 16 is placed through the
axial passageway of the seal means, and the package 23 connected
to the end of the small diameter tubing, whereupon the apparatus 12
is then engaged with the tubing so that the tubing can be forced
to move downhole after the valve 92 has been opened.
The embodiment seen in Figures 6 and 7 provides a ~ery
large interaction of surface areas between the confronting belt
faces and the outer peripheral surface of the tubing string. The
lS motors 60 and 80 can be fluid or electrical, In some instances,
it may be desirable to use the produced gas from -the formation 22
for operating the mo-tor when entering completed boreholes.
The packer 29 and vent assembly 28 of Figure 1 can be of
the type and operation as set forth in my previous Patent Nos.
3,871,448; 3,931,855; 4,040,485; and 4,151,880 to which reference
is made for further background of this inyention.
The perforating gun 24 and gun firing head, along with
package 23 can be made in accordance with my previous Patent Nos.
3,706,344; 3;717,095; and 3,717,099 to which reference is made for
further background of this invention.
It is often desirable to monitor the downhole pressure
simultaneously with the completion of the hydrocarbon producing
formation. The present invention enables this dat~ to be obtained
fro~ the surface o~ the earth, by forcing the package 23 to mo~e
downhole in a new and unobvious manner against the piston effect
of the wellbore.
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R. R. VANN
The tubular member 16 can be a slick line, wire line, or
capillary tubing. The package or mass 23 can be any object, in-
cluding a fishing tool or de-tonator device, which is to be moved
downhole. The gun 24 is an illustrative example of one downhole
device which can advantageously be used in combination with the
present invention.
As noted above, the prime mover, or motor 60 or 80, can
be a gas or expansion type motor, such as a commercially available
air driven motor. As seen in Figure 7, the gas from the borehole
can be valved to -the motor to provide a convenient supply of power
fluid.
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