Note: Descriptions are shown in the official language in which they were submitted.
CA 02665724 2009-05-08
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METHOD AND APPARATUS FOR REMOVING METAL CUTTINGS
FROM AN OIL WELL DRILLING MUD STREAM
FIELD OF THE INVENTION
The present invention relates to magnets that are used to
remove metal cuttings, metal shavings, metal parts, and like
metallic material from a flow stream of oil well drilling mud.
More particularly, the present invention relates to an improved
method and apparatus for removing metal cuttings, metal
shavings, metal parts and the like from an oil well drilling mud
flow stream wherein a magnetized bar has first and second end
portions, each carrying an end plate and wherein a non-magnetic
wiper plate attaches to the magnetized bar in between the end
plates, the wiper plate being slidable upon the magnetized bar
between the end plateS so that movement of the wiper plate from
one end plate to the other end plate enables removal of the
metal cuttings from the magnetized bar.
BACKGROUND
Magnets have been used to remove metal from a flow stream
of oil well drilling mud. Examples of commercially available
magnets can be seen at the Stacey Oil Services, Ltd. website
(www.staceyoil.com) and the Ceesan website (www.ceesan.net).
Such magnets are also known in the industry as "ditch magnets".
Some patents have issued for ditch magnets. One such patent is
U.S. Patent No. 3,498,455. Other possibly relevant patents are
listed chronologically in the following table.
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TABLE
PATENT NO. TITLE ISSUE DATE
2,792,115 Magnetic Separator 05-14-1957
3,498,455 Ditch Magnet 03-30-1970
3,713,499 Method and Apparatus for Treating 01-30-1973
Drilling Mud
4,030,558 Wear Determination of Drilling 06-21-1977
Bits
5,944,195 Method for Separation of Solids 08-31-1999
from Drilling Fluids by Magnetic
Separation and Centrifugation
6,354,386 Apparatus for Retrieving Metal 03-12-2002
Objects from a Wellbore
2006/0016732 High Gradient Magnetic Separator 01-26-2006
2007/0138103 Magnetic Separation in Fluids 06-21-2007
Many of the metal parts that are collected by the ditch
magnet are pieces that have been cut or shaved and are thus of
irregular shape and can have jagged edges, sharp points, or the
like. Safety is very important and meaningful in the oil and
gas industry today. Cuttings that are collected by a ditch
magnet can include sharp edged debris that could possibly cut
the hand of a worker who handles the ditch magnet.
Cuttings that have been retrieved from a ditch magnet can
provide information that is beneficial to oil and gas well
operators. These collected cuttings may indicate casing wear
during ordinary drilling operations, pipe wear, or any other
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,
,
factor which may be economically detrimental to the well or
production.
Time is an important factor in oil and gas well drilling.
The cost of drilling is rising.
With drilling, rig rates as
expensive as they are, a small part of time saved can equate to
significant savings. Oil and gas well drilling rates can be as
high as $125,000 to $600,000 per day.
Thus, any procedure or
apparatus that shortens the time for handling the ditch magnet
and/or its debris can be a significant savings in money.
BRIEF SUMMARY OF THE INVENTION
The apparatus of the present invention provides an improved
"ditch magnet" wherein a wiper flange of special configuration
moves longitudinally along to wipe off metal cuttings that have
become adhered to the magnet as it is immersed in a mass (e.g.
flowing) of drilling mud. The present invention is safe to use
because the wiper engages and wipes cuttings from the magnet.
Because such cuttings can be sharp, pointed or jagged, injury to
a worker can be avoided.
Because cuttings can be wiped into a container (such as the
very shipping container used to carry the ditch magnet), they
can be analyzed to determine their source (e.g. scrapings from
casing, broken part, etc.)
In accordance with the present disclosure there is provided
an apparatus for removing metal cuttings from a flowing liquid
stream of oil well drilling mud, comprising: a) a bar having a
first end portion that is a magnetic section, a second end
portion that is a non-magnetic section, an outer surface, and
wherein said bar has a generally uniform cross section; b) a
first end plate attached to one end portion and having a
peripheral portion extending radially away from the bar; c) a
second end plate attached to a second end of the magnetized bar
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with a connection that enables the second end plate to be
quickly disconnected from the bar, the second end plate having a
peripheral portion extending radially away from the bar; d) a
non-magnetic wiper plate having an opening that closely conforms
to the outer surface of the bar, the wiper plate and bar
defining an assembly, the wiper plate being slidable upon the
bar between the end portions so that movement of the wiper plate
from the magnetic section to a non-magnetic section effects
removal of metal cuttings from the bar by pushing the metal
cuttings from the outer surface of the bar next to the magnetic
section to the outer surface of the bar next to the non-magnetic
section; e) one or more handles on the wiper plate that enable a
user to manipulate said assembly; and f) wherein at least one of
said handles is in a peripheral portion of the wiper plate.
In accordance with the present disclosure there is also
provided an apparatus for removing metal cuttings from a flowing
stream of liquid oil well drilling mud, comprising: a) an
elongated member having a first end portion, a second end
portion, an outer surface, a magnetized section and a non-
magnetic section; b) wherein the non-magnetic section is joined
to the magnetic section at a location that is in between the
said first and second ends; c) a plate attached to each of said
elongated member end portions, each plate having a peripheral
portion that extends radially away from said outer surface of
said elongated member;d) a non-magnetic wiper plate having a
central opening that conforms to the outer surface of the
magnetized member, and the wiper plate and magnetized member
defining an assembly and wherein the wiper plate has a
peripheral portion that extends radially away from said central
opening, the wiper plate being slidable upon the magnetized
member; e) wherein said elongated member and said plates form an
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assembly; f) wherein movement of the wiper plate from the first
end to the second end enables removal of metal cuttings from the
magnetized section of the elongated member when the wiper plate
and cuttings travel from the magnetic section to the non-
magnetic section; and g) wherein one of said plates has at least
one opening in said peripheral portion and spaced laterally away
from the outer surface of the elongated member, said opening
being sized and shaped to receive a hand of a human technician
when a technician handles the said assembly.
In accordance with the present disclosure there is also
provided an apparatus for removing metal cuttings from oil well
drilling mud, comprising: a) a bar having first and second end
portions, an outer surface, a generally uniform cross section, a
magnetized part, and a non-magnetized part that is in between
the magnetized part and one of said bar end portion; b) a first
end plate attached to one end portion and extending radially
away from the magnetized part of the bar; c) a second end plate
attached to the second end of the magnetized part of the bar
with a connection that enables the second end plate to be
quickly disconnected from the magnetized part of the bar; d) a
non-magnetic wiper plate positioned in between the end plates
and having an opening that closely conforms to the outer surface
of the magnetized part of the bar, the wiper plate being
slidable upon the magnetized part of the bar between the end
plates so that movement of the wiper plate from one end plate to
the other end plate enables movement of metal cuttings from the
magnetized part of the bar to the non-magnetized part of the
bar.
In accordance with the present disclosure there is also
provided a method of removing metal cuttings from oil well
drilling mud stream comprising the steps of: a) providing a bar
with end plates attached to opposed end portions of the bar, one
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of the end plates being connected to
the bar with a
disconnectable connection, wherein the bar has a magnetized part
and a non-magnetized part; b) mounting a wiper plate on the bar
in between the end plates, the wiper plate having an opening
with a shape that closely conforms to the outer surface of the
bar; c) placing the bar in an oil well drilling mud flow stream;
d) allowing metal cuttings to accumulate on the magnetized part
of the bar over time; e) removing the bar from the oil well
drilling flow stream; and f) moving the wiper from one end
portion of the bar to the other end portion of the bar, wiping
the metal cuttings from the outer surface of the magnetized part
of the bar; and g) wherein in step "f the cuttings are moved to
the non-magnetized part of the bar.
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BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and
advantages of the present invention, reference should be had to
the following detailed description, read in conjunction with the
following drawings, wherein like reference numerals denote like
elements and wherein:
Figure 1 is an elevation view of the preferred embodiment
of the apparatus of the present invention;
Figure 2 is a side view of the preferred embodiment of the
apparatus of the present invention taken along lines 2-2 of
figure 1;
Figure 3 is a perspective view of the preferred embodiment
of the apparatus of the present invention;
Figure 4 is a fragmentary perspective view of the preferred
embodiment of the apparatus of the present invention;
Figure 5 is a side view of the preferred embodiment of the
apparatus of the present invention and showing part of the
method of the present invention;
Figure 6 is a side view of the preferred embodiment of the
apparatus of the present invention and showing part of the
method of the present invention;
Figure 7 is a perspective view of the preferred embodiment
of the apparatus of the present invention and showing part of
the method of the present invention; and
Figure 8 is a schematic diagram illustrating part of the
method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Figures 1-8 show the preferred embodiment of the apparatus
of the present invention designated generally by the numeral 10
in figures 1-3 and 5-7. In the drawings, the numeral 10 shows
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an apparatus for removing metal from drilling mud, which
apparatus 10 can also be referred to as a "ditch magnet".
The apparatus 10 is typically placed in a flow stream of
drilling mud such as in the flow stream 63 shown in figure 8.
Such a flow stream 63 can be any part of the structure of an oil
and gas well drilling platform that utilizes drilling mud. One
location that could be used as flow stream 63 for placement of
the apparatus 10 is a vessel associated with oil and gas well
drilling that is commonly referred to as "the ditch" or the
"possum belly" section 60. The apparatus 10 could also be
placed in a pipeline or other flow stream that conveys drilling
mud to shale shakers or other solids removal equipment that
might be employed as part of the oil and gas well drilling mud
system.
Over a period of time, a magnetic body 17 of apparatus 10
will attract metallic objects or material 51 that is flowing in
the drilling mud stream (see arrows 15 in figure 5). This
metallic material can be cuttings, shavings, broken metal parts
or the like. These unwanted metallic materials are generated as
a part of oil and gas well drilling operation, fishing
operation, milling operation, and/or completion operation. Such
parts are at times lost in the well, or can be cut or shaved
from casing or tubing as part of well drilling operations.
In figure 8 there is shown schematically the various
components of an oil and gas well drilling rig. The drilling
rig includes a derrick 52 that supports a drill string 53. At
the lower end portion of the drill string 53 there is provided a
drill bit 54. The drill bit 54 cuts formation material which
enters a drilling mud stream.
The drilling mud is pumped into the well via a discharge
flow line 56 using a discharge or mud pump 55. At the drill
bit, the drilling mud collects drill cuttings and conveys them
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back to the surface. At the surface, a return flow line 57
carries the drilling mud and cuttings to a shale shaker 58.
The shale shaker 58 removes solid material such as the rock
cuttings that are cut by the drill bit 54. Drilling mud then
enters tank or vessel 59 that can have multiple sections such as
a possum belly section 60 and a suction pit section 61. Suction
line 62 communicates between tank 59 and pump 55. The apparatus
of the present invention can be placed at any number of
locations in the schematic diagram of figures 5 and 8 such as
for example in possum belly 60, in suction pit 61 or in other
locations where drilling mud flows or is contained.
A shipping container can be used to transport apparatus 10.
Such a container provides an interior having a lid or cover.
The lid or cover can be attached to the shipping container using
a hinge and latch.
Magnet assembly 16 provides an elongated magnet body 17
having a plurality of sides 11, 12, 13, 14. Each of the sides
11-14 can be, for example, rectangular in shape. Magnet 17
provides end portions 19, 20. Plate 21 is attached to magnet 17
at end portion 19. This attachment can be for example a bolted
connection, using a bolt 22 or other like fastener that connects
to an internally threaded opening in the upper end portion 19 of
magnet body 17. Magnet body 17 can be an assembly that includes
an outer hollow shell (e.g. stainless steel) and one or more
magnets housing inside the shell. Magnet or magnets contained
internally of such a hollow shell could extend between end
portion 19 and reference line 49. Thus no magnets would extend
between reference line 49 and end portion 20.
Plate 21 can provide spaced apart openings 23, 24 as shown
in figure 3. Each opening 23, 24 can include a rectangular
section 25 and a semi-circular section 26. The semi-circular
section 26 enables a rope, cable, chain, or other connector to
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*
form a connection with plate 21 at opening 23 or 24. Such
opening 23 or 24 can be employed when the ditch magnet 10 is to
be suspended from a rope, cable, chain, hook, or the like.
Openings 23, 24 also enable a technician 50 to grip and
lift ditch magnet 10 at plates 21, 27 when transporting the
ditch magnet 10 from one location to another, or when removing
it from its shipping container, or when placing it into a
shipping container.
Plate 27 is a plate that is removable from magnet body 17
using a disconnectable, quick release or detachable connection.
The plate 27 can be disconnectable from magnet 17 in a minimum
of time so that its removal will facilitate the removal of any
metal shavings, metal cuttings, metal parts, or other metallic
objects 51 that are affixed to the outer surface or sides 18 of
magnet body 17. The plate 27 provides openings 28, 29. Each of
the openings 28, 29 has a generally rectangular section 30 and a
semi-circular section 31 as with plate 21.
Plate 27 provides a central opening 32. Sleeve 33 is
connected (for example, welded) to plate 27 at central opening
32. Sleeve 33 provides sleeve bore 34 that is generally aligned
with central opening 32 as shown.
In figures 4-7, magnet body 17 provides end surface 35
fitted with pin 36. Pin 36 provides a pin opening or channel 37
that is receptive of a locking pin 40. Upon assembly of plate
27 to magnet body 17 at pin 36, sleeve openings 38, 39 align
with pin opening or channel 37. In this fashion, locking pin 40
can pass through each of the openings or channels 37, 38, 39 to
form a locking connection between the sleeve 33 and pin 36 as
shown in figures 1-2. Locking pin 40 can be attached to plate
27 using a ring 41, tether 42 and fastener 43.
Wiper plate 44 is preferably a non-metallic plate, being
constructed for example of polymeric material, plastic material,
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or other like material. Wiper plate 44 is preferably non-
metallic. Plate 44 provides openings 45, 46 as well as central
opening 47. The central opening 47 is of a size and shape that
conforms to the transverse cross-section of magnet body 17 as
shown in figures 2, 3 and 4.
Figures 5-7 illustrate a removal of cuttings, metallic
shavings, metal parts or like metal objects 51 from magnet 17
using wiper plate 44. In figure 7, a technician 50 places ditch
magnet 10 on a suitable surface or into a container. The
technician 50 moves wiper plate 44 in a direction indicated by
arrow 48 from a beginning position next to plate 21 downwardly
toward end 20.
The technician removes locking pin 40 so that plate 27 can
be separated from magnet 17. As indicated by the reference line
49, the part of magnet 17 in between reference line 49 and plate
27 is preferably not magnetized. When wiper plate 44 has pushed
downwardly toward plate 27, metal objects, cuttings, shavings,
parts or the like that reach reference line 49 will no longer be
subjected to a magnetic field and will fall from magnet body 17
to a floor or other surface or into a container.
Removed metallic material 51 can either be saved for later
analysis and/or properly disposed of.
The following is a list of parts and materials suitable for
use in the present invention.
PARTS LIST
Part Number Description
apparatus for removing metal from
drilling mud
11 side
12 side
13 side
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14 side
15 arrow
16 magnet assembly
17 magnet body
18 side
19 end portion
21 plate
22 bolt/fastener
23 opening
24 opening
25 rectangular section
26 semi-circular section
27 plate
28 opening
29 opening
30 rectangular section
31 semi-circular section
32 central opening
33 sleeve
34 sleeve bore
35 end surface
36 pin
37 pin opening/channel
38 sleeve opening
39 sleeve opening
40 locking pin
41 ring
42 tether
43 fastener
44 wiper plate
45 opening
46 opening
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47 central opening
48 arrow
49 reference line
50 technician
51 metal cuttings/shavings/ parts /
objects
52 derrick
53 drill string
54 drill bit
55 pump
56 flow line
57 flow line
58 shale shaker
59 tank/vessel
60 possum belly section
61 pit section
62 suction line
63 flow stream
All measurements disclosed herein are at standard
temperature and pressure, at sea level on Earth, unless
indicated otherwise. All materials used or intended to be used
in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example
only; the scope of the present invention is to be limited only
by the following claims.
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