Note: Descriptions are shown in the official language in which they were submitted.
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METAL DEBRIS CLEANOUT SYSTEM AND METHOD
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a system and method for removal of
metal debris
from a norrnal path of a fluid flow, such as the flow of re-circulated fluid
generated during
drilling/completion operations.
[0002] The drilling or completion operation results in metal debris generated
in the well
bore. The debris is suspended in the highly viscous drilling fluid or other re-
circulated fluid and
must be periodically removed from the well bore in order to improve the well
production and avoid
damage to equipment operating within the well bore, such as pumps and the
like. The drilling fluid
carries with it pieces of metallic shavings that are particularly dangerous
for the operation of
equipment during completion and production operations.
[0003] Conventionally, the drilling fluid is pumped to the surface, cleaned
and recirculated
back into the well bore. Shale shakers and similar equipment is often used to
remove chunks of
formation, metal pieces and other such objects. The drilling fluid is then
delivered to a mud pit,
flowing along a ditch, which may be 100 feet long. The mud pit allows the
smaller particles to settle
on the bottom, while the drilling fluid, now relatively free of debris, is
pumped back to the rig floor
by pumps.
[0004] In order to solve the metal debris problem, the conventional technique
provides for
the use of various magnets in the ditch for intercepting the flow of fluid
through the ditch and
capturing as many metal objects as possible. However, the collection magnets
are difficult to
retain in the viscous fluid flow, and the metal collected on the magnets is
difficult to remove.
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[0005] The present invention contemplates elimination of drawbacks associated
with the
prior art and provision of a metal debris cleanout system, tool and method
that can be used for
removal of metal debris from the drill mud and other similar re-circulating
fluids.
SUMMARY OF THE INVENTION
[0006] It is, therefore, an object of the present invention to provide a metal
debris cleanout
system that allows entrapment of metal debris in the circulation fluids before
the re-circulated fluids
are returned to a well bore.
[0007] It is another object of the present invention to provide a metal debris
cleanout method
for capturing metal debris in the flow of re-circulating flow.
[0008] These and other objects of the present invention are achieved through a
provision of a
system for removing metal debris from a fluid flow, which comprises at least
one magnetic unit
comprising a hollow sleeve and a removable magnetic core positioned in the
sleeve. The magnetic
unit is placed in the normal path of the fluid flow, such that the fluid
contacts the sleeve and the
metal debris settles on the exterior of the sleeve. Once the operator detects
sufficient accumulation of
the metal particles on the sleeve, the operator removes the magnetic unit from
the fluid path and
removes the magnetic core. The metal debris falls under gravity from the non-
magnetic sleeve and
can be collected for disposal. The magnetic unit can then be re-positioned in
the fluid flow path for
further collection of the metal debris.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Reference will now be made to the drawings wherein like parts are
designated by like
numerals and wherein
[0010] Figure 1 is a schematic view illustrating circulation of fluid from and
to a well bore.
[0010] Figure IA is a schematic detail view of a re-circulated fluid line
showing a plurality
of fluid deflectors positioned therein.
[0011] Figure 2 is an exploded view of the cleanout magnetic unit in
accordance to the
present invention.
[0012] Figure 3 is a detail view showing a magnetic core positioned in the non-
magnetic
sleeve.
[0013] Figure 4 is a top view of the hollow sleeve with the magnetic core
removed.
[0014] Figure 5 is a detail view illustrating position of a fluid deflector
member and a pivot
shaft secured to a base plate.
[0015] Figure 6 is a side view illustrating the fluid deflector member and the
magnetic unit
of the present invention, with the handle removed.
[0016] Figure 7 is a schematic view illustrating position of the fluid
deflector member
relative to the magnetic unit such that a trap area is formed therebetween.
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[0017] Figure 8 is a schematic side view illustrating position of the
plurality of magnetic unit
and fluid deflector member in a fluid return ditch.
[0018] Figure 9 is a schematic top view illustrating the cleanout system of
the present
invention utilizing a plurality of magnetic tool units positioned within a
fluid return ditch.
[0019] Figure 10 is a schematic view illustrating positioning of the magnetic
tool units using
a different positioning choice of the magnetic units on the base plate.
[0020] Figure 11 is a schematic view illustrating still another variation in
the magnetic units
placement.
[0021] Figure 12 is a schematic view illustrating still further variation in
the magnetic unit
placement in the return ditch.
[0022] Figure 13 illustrates a magnetic unit with the metal debris settled on
the hollow
sleeve.
[0022] Figure 14 illustrates easy removal of the metal debris from the hollow
sleeve upon
removal of the magnetic core.
DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Turning now to the drawings in more detail, numeral 10 designates the
metal debris
cleanout system in accordance with the present invention. As can be seen in
Figure 1, the system 10
can be positioned in one or more locations in a fluid return ditch 12, which
extends between a surface
cleanout device, for instance, a shale shaker 14 and a circulating fluid
collection area, such as a mud
pit 16. The circulating fluid, such as the drilling mud, is delivered to the
shale shaker via a conduit
18 from a well bore (not shown). The shale shaker 14 typically comprises a
screen through which
chunks of formation, metal shavings and the like drop by gravity into a
container positioned below
the screen. The drilling mud or other re-circulated fluid, now free from
relatively large pieces of
debris, is allowed to flow to the fluid return ditch 12 that is slightly
inclined to allow the fluid to flow
to the mud pit 16 where heavier debris settles on the bottom, while lighter
circulating fluid is pumped
by one or more pumps 20 into a return line 22 for delivery to the rig floor
(not shown). The cleanout
system 10 of the present invention is positioned in the normal path of the
fluid flow, such as re-
circulating fluid line schematically shown in Figure 1A. The re-circulated
fluid 24 flows along the
bottom 26 of the return ditch 12.
[0024] Each system 10 comprises a plurality of magnetic units 30, each
provided with a
corresponding fluid deflector member 32, which is positioned upstream from the
magnetic unit 30.
The fluid flow deflector member 32 comprises an upright solid body 34, which
has outside
dimensions preferably at least slightly greater than oirtside dimensions of
the magnetic mit 30. The
deflector member 30 has a generally-V-shaped cross section and is shown
comprising a pair of
angularly secured portions 36 and 38. The portions 36 and 38 may be connected
together at an acute
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angle, at a right angle, or at an obtuse angle, depending on the particular
design selected by the user.
The deflector member re-directs the fluid flow and prevents a direct impact of
the fluid on the
protected magnetic unit 30. The pattern of the fluid flow is shown by arrows31
in the drawings. As a
result of positioning the deflector members 32 in the direct path of the fluid
flow, the velocity of the
flow is reduced and a plurality of turbulent areas are created on the edges of
the deflector portions 36
and 38. At the same time, reduced velocity flow areas are created between the
downstream sides 40,
42 of the deflector member 32. The deflector 32 redirects fluid movement and
also creates an
"Eddy" effect. This prevents flushing of the debris caught on the magnetic
unit 30 under the strong
force of the fluid flow. In addition the fluid deflector 32 creates a
plurality of trap areas 44 allowing
additional debris to be removed from the flow of the drilling fluid through
the ditch 12. The magnetic
tools 30 are positioned within the less turbulent zones, partially protected
by the deflectors 32.
[0025] Each of the magnet assemblies 30 comprises a magnet insert, or core 50
configured
for removable positioning within a hollow sleeve 52. The sleeve 52 is formed
from a non-magnetic
material, for instance, stainless steel, while the magnet insert 50 is made
from rare earth materials.
The insert 50 comprises an upper end 54 and a lower end 56, each provided with
a cutout having
interior threads 58. A handle 60 has a stern 62 provided with exterior threads
matching the threads
58 on both ends of the insert 50. Should one of the threads 58 become damaged,
the orientation of
the insert 50 can be reversed, and the handle 60 can be engaged with either
end of the magnetic insert
50.
[0026] A ring-shaped collar 64 is secured adjacent the top of the sleeve 52.
The collar 64
has diameter greater than the exterior of the sleeve 52, the purpose of which
will be explained in
more detail hereinafter. A pivot sleeve 66 is fixedly attached to the sleeve
52 and extends in a
tangential relationship to the exterior surface of the sleeve 52. The pivot
sleeve 66 is adapted for
mounting over an upright pivot shaft 70. A pivot stop 72 is secured adjacent
the lower part of the
pivot shaft 70 transversely to a normal axis of the pivot shaft 70. The bottom
74 of the pivot sleeve
66 rests on the pivot stop 72 when the sleeve 66 is engaged with the pivot
shaft 70. When mounted
on the pivot shaft 70, the hollow sleeve 52, along with the pivot sleeve 66,
is allowed to pivot about a
vertical axis defined by the shaft 70 in the directions shown by arrows 80 in
the drawings. The
limited pivotal movement of the sleeve 62 allows the magnetic field created by
the magnet insert 50
to span along a greater area within the fluid flow and collect more metal
debris. The core 50 and the
sleeve 52 are designed to swing with the prevailing drill fluid current,
allowing the magnets to adjust
to a comfortable position within the fluid flow to maximize the debris
collection process.
[0027] The pivot shaft 70 and the fluid deflectors 32 are fixedly secured on a
base plate 90
which supports one or more fluid deflectors 32 and one or more pivot shafts 70
thereon. The sleeves
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52, 66 and with the magnet inserts 50 can be easily removed from the base
plate 90 when necessary
during operation of the instant system.
[00281 In operation, the user positions the base plate 90 with a cleanout
magnetic tool in the
normal fluid path of the re-circulated fluid, such as for instance ditch 12.
The base plate 90 rests on
the bottom with the magnetic units 30 and the deflector members 32 extending
upwardly, as shown
schematically in Figure I. The fluid flow is allowed to flow past the magnetic
unit, in the direction
shown by arrows 92 in Figure 9, moving around the deflector members 32, while
the magnetic core
attracts the metal debris from the fluid flow and causes it to settle on the
exterior of the hollow sleeve
52 and the pivot sleeve 66. The operator monitors the accumulation of metal
particles and, once it is
determined that the amount of metal debris attracted is approaching a critical
limit, the operator
slides the pivot sleeve 66 from the pivot shaft 70 and removes the sleeves 52,
66, along with the
magnetic core 50 from the base plate 90. The unit 30 is then positioned in a
container schematically
designated by numeral 94 in Figure 14, which is large enough to accommodate
the unit 30. The
operator then removes the core 50 by lifting it by the handle 60. Once the
magnetic core 52 is
removed, the magnetic field ceases to act on the metal debris 96 and it falls
under gravity to the
bottom of the container 94. The ring collar 64 prevents the debris 96 from
following the movement
of the magnetic field generated by the insert 50 and stops the metal debris 96
from moving beyond
the limits defined by the ring 64. Once the sleeves 52 and 66 are free from
the debris, the sleeves 52.,
66 are lifted from the container 94, the magnetic insert 50 is reinserted into
the sleeve 52 and the unit
is ready for positioning on the pivot shaft 70 again. The debris 96 can be
recovered in the container
and analyzed at the operator's convenience or disposed of in an
environmentally safe manner.
[0029] The present invention provides an efficient and easy to operate metal
debris removal
system and method. In comparison with conventional methods of metal debris
removal, which is
time consuming and labor intensive, the removable magnet insert allows to
safely and easily remove
the accumulated metal from the outside of the sleeve and immediately reuse the
unit without the need
for complex cleanup by pressure washing, scraping and other such means that
are currently used in
the industry.
[0030] Many changes and modifications can be made in the design of the present
invention.
