Note: Descriptions are shown in the official language in which they were submitted.
CA 02631414 2008-05-15
Safety Net for a Drill Rig
Background
Top drives are used in drill rigs also called derricks for wellbore
operations.
During use top drives are hoisted above the drill floor of a rig sometimes
well above personnel
working below. It sometimes occurs that parts fall off a top drive during
operations and may fall
onto the drill floor below. This may cause a safety concern for workers on the
rig.
Summary
In accordance with a broad aspect of the present invention, there is provided
a safety net for a top
drive, the safety net comprising: a body having an upper end and a lower end,
the upper end
including fasteners for connecting the upper end of the safety net to the top
drive and the lower
end including an inwardly directed return for extending inwardly beneath the
underside of the
top drive; and an opening through the body for accessing the top drive from
outside the net.
In accordance with another broad aspect of the present invention, there is
provided a top drive
installation comprising: a top drive supported in a rig, the top drive
including a motor housing
oMSl..cgtiI oõu65 0001 1 ?869776~I
CA 02631414 2008-05-15
-2-
including a top end, an underside and a quill extending from the underside; a
safety net installed
on the top drive, the safety net including an upper end; a lower end including
an inwardly
directed extension for extending inwardly beneath the underside of the top
drive; and fasteners
for connecting the safety net to the top drive.
It is to be understood that other aspects of the present invention will become
readily apparent to
those skilled in the art from the following detailed description, wherein
various embodiments of
the invention are shown and described by way of illustration. As will be
realized, the invention
is capable for other and different embodiments and its several details are
capable of modification
in various other respects, all without depai-ting from the spirit and scope of
the present invention.
Accordingly the drawings and detailed description are to be regarded as
illustrative in nature and
not as restrictive.
Brief Description of the Drawings
Referring to the drawings, several aspects of the present invention are
illustrated by way of
example, and not by way of limitation, in detail in the figures, wherein:
Figure 1 is a schematic illustration of a top drive and a drill rig system
including a safety net.
Figure 2 is a schematic illustration of a top drive including a safety net
installed thereon.
Figure 3 is a schematic perspective drawing of an upper part of a safety net.
Figure 4 is a schematic perspective drawing of a lower part of a safety net.
Figure 5 is a sectional view through flanges of an upper part and a lower
part.
Figure 6 is a schematic perspective drawing of a back up wrench net.
DMS I.cgak055065'.0001 1 28687760
CA 02631414 2008-05-15
-3-
Description of Various Embodiments
The detailed description set forth below in connection with the appended
drawings is intended as
a description of various embodiments of the present invention and is not
intended to represent
the only embodiments contemplated by the inventor. The detailed description
includes specific
details for the purpose of providing a comprehensive understanding of the
present invention.
However, it will be apparent to those skilled in the art that the present
invention may be practiced
without these specific details.
A safety net has been invented for preventing material from falling from a top
drive to a drill
floor therebelow. In one embodiment, a drill rig system for onshore or
offshore operations is
provided including a rig frame, a top drive suspended in the rig on a block,
and a safety net
secured about the top drive and extending therebelow to block at least some of
the open access
below the top drive, such that materials falling by gravity from the top drive
may be caught in
the net.
Top drives vary in form, configuration and size, depending on various
parameters, such as their
power rating, manufacturer, power source, mode of operation, etc. However, top
drives do have
several features in common. For example, with reference to Figure 1, a top
drive 10 is generally
suspended in a rig 12 above the drill floor 13 usually by means of a block and
hook 14. Top
drive 10 generally includes a swivel 10a, a main housing lOb that accommodates
the gear box
and motor, hydraulics and a quill 10d. Quill 10d extends out from the
underside of the main
housing and is driven to rotate by the components in the main housing. A top
drive often is also
secured through a lateral connection to a torque track arrangement 16. A top
drive has numerous
items thereon such as caps, covers, bolts, connectors, pins, to name a few,
that can work loose,
break off, etc, and may drop onto the drill floor.
DMSLegal',055065'00011 2868776v1
CA 02631414 2008-05-15
-4-
A safety device includes a net 20 with an upper end 20a, a lower end 20b and,
possibly if the net
is rectangularly fonned, sides. The safety device further includes fasteners
24 integrated in or
separate from the net for securing the net to a top drive. Fasteners 24 may
include one or more
of straps, belts, hook and loop connectors, bolts, ties, flanges, catches,
etc. Fasteners 24 may be
durable and releasable to allow for removable installation.
The net niay be formed to cover various parts of the top drive including the
main housing,
components below the main housing, etc. Net 20, in the illustrated embodiment,
covers at least a
portion of the main housing l Ob of a top drive. The net may be secured by
fasteners 24 to extend
down over the top drive main housing and with lower end 20b coming in below
the housing to
close off at least some of the openings below the housing. For example, net 20
may be secured
as by, and only stated for example, tying off upper end 20a of the net above,
and lower end 20b
of the net below, the top drive main housing I Ob. For example, net 20a can be
forned to extend
from a position below block 14 or, possibly, below swivel l0a and can include
a bottom return as
by gathering, tapering, forming, fastening, etc. that extends a distance
around and beneath the
underside of the top drive main housing l Ob.
A top drive generates significant heat during operation. The net may allow
ventilation of the top
drive and may be heat and oil resistant such that it is not adversely affected
by the heat and
operational conditions from the top drive. For example, the net may include a
plurality of small
openings to allow the t1ow of air therethrough into the top drive. In one
embodiment, the net
includes a heat resistant, flexible mesh fortned of strands interconnected,
interlaced, woven or
knit to form openings of less than one inch in diaineter. For example, a mesh
with regular and
numerous 1/2 or '/4 inch openings may be useful to form all or a portion of
the net. Such a mesh
may catch very small objects such as pins, nuts and bolts while allowing heat
to easily dissipate
from the top drive.
Net 20 may include access openings 26, sucll as slots or windows positioned as
necessary for
access to the top drive, for example for inspection, routine servicing,
changing filters, etc.
DM SLega1 055065 ,0001 1 2868776v I
CA 02631414 2008-05-15
-5-
Access openings 26 may, if desired, include closures 27 such as fasteners,
flaps, covers, etc. to
close off the openings when access is not required.
Net 20 may further include holes for connections of external parts to the top
drive such as, for
example, including the connection of hydraulic lines, connection to the torque
track, extension
therethrough of the quill, pipe handler bails, bail rams, etc. For example,
the sides can be fonned
to create an opening therebetween such that the net can be wrapped around main
housing 10b
and secured thereabout but leave a hole between the sides for connection of
the top drive to the
torque track. Holes can include fittable (i.e. elastomeric, gatherable, etc.)
and/or fixed opening
sizes.
Referring to Figures 2 to 5, another embodiment of a net is shown. The
illustrated net includes a
plurality of parts such that the parts of the net can be installed on various
portions of the top
drive and can be interconnected but allow movement therebetween. For example,
one net part
can be installed in a fixed position on the top drive housing 110b, while a
second net part can be
installed on a moveable part of the top drive to move therewith. A connection
may be provided
between the parts of the net to pennit relative movement therebetween.
For example, as shown, the net may include an upper part 150 and a lower part
162. Upper part
150 includes an upper end 151, sides 152, a lower end 153 and fasteners 156
for securing the net
in place on a top drive. Upper part 150 is sized and formed to fit about a
motor housing 110b of
a top drive. Upper end 151 may be gathered, tapered or otherwise formed if
desired to reduce
the size thereof. Lower end 153 is gathered as at 153a, tapered or otherwise
foimed to neck in
around the underside of the motor housing. Sides 152 are selected to be of a
length to extend
down along the motor housing from upper end 151 to lower end 153.
Lower end 153 further includes an annular flange 158 encircling a lower
opening. Flange 158
defines the outer limits of opening 160 and is selected to hold its shape
although it may be
resilient to allow flex thereof, after which it returns to its original
annular shape. Flange 158
DMSLegal'.055065 0O011 28657760
CA 02631414 2008-05-15
-6-
forms a swivel support for an upper end of lower part 162 of the net. Flange
158 may include a
swivel track 164 thereon and/or a low friction surface, such as may include a
low friction upper
surface coating such as may include a polytetrafluoroethylene or a polymer
with similar
properties.
Lower part 162 includes an upper end, a lower end and fasteners 166 for
securing the net in place
on a top drive. Lower part 162 is sized and formed to fit below motor housing
110b, and in
particular, about the pipe llandler, rotary manifold and upper quill sections
110d of a top drive.
As will be appreciated, in some top drives, the pipe handler, rotary manifold
and upper quill
sections II Od of some top drives may rotate slightly relative to the top
drives motor housing
110b. Lower part 162 may be configured to allow for such rotation relative to
upper part 150,
which is secured to motor housing 1 l Ob.
For example, the upper end of lower part 162 may be formed to be supported on
annular flange
158 of the upper part 150. In particular, the upper end may include an
outwardly extending
flange 178 and a body 179 extending downwardly therefrom. Body 179 fits
througb opening
160 and flange 178 rests on and is supported by flange 158. Flanges 158 and
178 may be fonned
to coact to allow rotation of the lower part flange 178 on the upper part
flange 158 and therefore
body 179 within opening 160. Flange 178 may include a swivel track 182 thereon
that fits into
or engages on swivel track 162 and/or a low friction surface, such as may
include a low friction
surface coating such as may include a polytetrafluoroethylene or a polymer
with similar
properties.
Lower part 162 may, therefore, be fixed to the pipe handler and upper quill
110d to move with
them, while remaining connected to, but able to move relative to, upper part
150. Lower part
162 may be fixed to the pipe handler and quill sections in various ways. For
example, lower part
162 may include a lower necked region 184 that fits tightly about upper quill
110d. The tight fit
allows the necked region to be substantially secured to move with the quill
110d. Lower part
162 may fizrther include openings 186, 187 through which the bails 188 or bail
ears and bail rams
Dh1Sl.egal o55Q65.O0O1 1 2868776vI
CA 02631414 2008-05-15
-7-
189, respectively, can be inserted for extension therethrough. Openings 186
may include
elastomeric, pleated, etc. forms to ensure that the net is able to move with
the parts and allows
some flexibility in fit, while seeking to close off gaps therebetween.
Lower part 162 can be formed for installation by pulling up over the parts or
may include
installation slits 190 and fasteners 190a to secure the net about the
underside components of the
top drive. In one embodiment, lower part 162 includes a full length opening
defined by sides
191 to allow the net to be installed by wrapping the sides about the top drive
components and
fitting the bails and bail rams into their openings 186, 187 through slits
190. In such an
embodiment, flange 178 may be formed as a c-shaped structure, which can be
opened to fit about
the top drive components but then return into its annular shape. Flange 178
may therefore be
formed of materials that allow it to flex, when force is applied but is
resilient to return to its
annular shape.
ln one possible embodiment, a third part 192 may be provided to fit about a
back up wrench 193
of a top drive. Third part 192 may be used separately from or together with
parts 150 and 162.
Third part 192 may be formed as a sleeve that may be fit over the back up
wrench and may
include an open upper end 194 including fasteners 195 for securing the net to
the upper end of
back up wrench 193 and a formed end 196 to fit over the lower, acting end of
wrench 193.
Formed end 196 may include an opening 197 for passage therethrough of quill
110d. Opening
197 may include a pair of aligned apertures sized to correspond to the inner
diameter through the
back up wrench. The body of part 192 between ends 194, 196, may include a
slack region 198 to
allow for extension of the back wrench therewithin, while ends 194, 196 remain
in place on the
back up wrench. Slack region 198 may include pleats and/or elastomeric
sections to allow the
net to extend with the wrench.
Fasteners 156, 166, 195 may take various fonns, as noted previously in
reference to Figure 1,
and may include more than one form on any particular net part. Some fasteners,
such as
fasteners 166 may include snaps, catches, bolts, hook and loop-type fasteners
to secure two parts
DnlsLegar0550650001 1 2868776v1
CA 02631414 2008-05-15
-8-
of the net together. Alternately or in addition, some other fasteners, for
example, fasteners 156
and 195 may include strap or belt forms that permit the net to be secured by
wrapping the strap
about a point on the top drive. In another embodiment, reinforced eyelets 156a
may be provided
to permit bolts, such as bottom housing bolts 199 of the top drive, to be
inserted to hold the net in
place on a component of the top drive. Referring particularly to the
illustrated net's upper part
150, it may include straps 156 for securing the upper end of the upper part
150 to the wash pipe,
swivel and/or upper tubes of the traction motor frame. The lower end of the
upper part 150 may
include reinforced eyelets 156a positioned to align with and fit over bottom
housing bolts 199.
The reinforcement 157 about the eyelets 156a may extend between eyelets and/or
to attach to
flange 158 such that the flange is finnly supported with eyelets 156a on bolts
199.
Openings 156 may be provided through the body of the net in any one of the
parts to provide
access to the top drive therethrough.
To install the upper part 150, the straps 156 may be installed by wrapping and
securing about
their mounting points and then lower end can be fit about the lower end of the
housing 110b.
Nuts on bolts 199 can be removed, eyelets 156a can be fit over bolts 199 and
the nuts reinstalled
such that the net is held pinched between the housing and the nuts on bolts
199. In this way, the
upper part of net is affixed to the motor housing, without the ability of the
upper part net to twist
on the housing.
Lower part 162 may be fit over the pipe handler, rotary manifold and quill
sections, as for
example, by wrapping the net about the parts, as noted previously, and
securing the necked
region tightly about the quill. The flange 178 is then interfit onto flange
158 for support and
relative rotation therebetween.
If' used, third part 192 can be fit over the back up wrench by pulling upper
end 194 of the net up
over the working end and along the telescoping region and securing straps 195
about the wrench
upper end. Openings 197 can be adjusted to align with the opening of the
working end.
DMSLega105506500011, 2868776v1
CA 02631414 2008-05-15
-9-
Net parts 150, 162, 192 can be fonned to include mesh sections, as described
hereinbefore with
respect to Figure 1. The mesh may be formed of heat and oil resistant
materials such that they
are able to withstand the conditions about the top drive. Materials such as
nitriles,
polyvinylchloride, etc. may be useful. Mesh sections may be secured to
fasteners, edge
reinforcements, reinforcements 157, flanges 158, 178, etc. by various means.
For example,
connections may be by stitching, polymer welding, fonning, defonnation, etc.
The previous description of the disclosed embodiments is provided to enable
any person skilled
in the art to make or use the present invention. Various modifications to
those embodiments will
be readily apparent to those skilled in the art, and the generic principles
defined herein may be
applied to other embodiments without departing from the spirit or scope of the
invention. Thus,
the present invention is not intended to be limited to the embodiments shown
herein, but is to be
accorded the full scope consistent with the claims, wherein reference to an
element in the
singular, such as by use of the article "a" or "an" is not intended to mean
"one and only one"
unless specifically so stated, but rather "one or more". All structural and
functional equivalents
to the elements of the various embodiments described throughout the disclosure
that are know or
later come to be known to those of ordinary skill in the art are intended to
be encompassed by the
elements of the claims. Moreover, nothing disclosed herein is intended to be
dedicated to the
public regardless of whether such disclosure is explicitly recited in the
claims. No claim element
is to be construed under the provisions of 35 USC 112, sixth paragraph, unless
the element is
expressly recited using the phrase "means for" or "step for".
>
DMSLcgaP,055065'.0001 1 2868776%,1
