Note: Descriptions are shown in the official language in which they were submitted.
21 86201
TITLE OF THE INVENTION:
valve for a two way hydraulic drilling jar and a two way
hydraulic drilling jar
NAME OF INVENTOR:
Aureliusz (Eric) Tadeusz Raczynski
FIELD OF THE INVENTION
The present invention relates to a valve for a two way
hydraulic drilling jar and a two way hydraulic drilling jar.
R~R~ROUND OF THE INVENTION
A drilling jar is placed on a drill string attached to a
drill bit when drilling oil and gas wells. As the name
drilling "jar" implies, the function of this tool is to provide
a jarring impact to free the drill bit, should it become stuck.
A drilling jar generally consists of a first tubular member
which telescopically receives a second tubular member. The
second tubular member is capable of limited axial movement
within the first tubular member, referred to as a "stroke".
The first tubular member has an impact surface referred to as
an "anvil". The second tubular member has an impact surface
referred to as a "hammer". At the end of each stroke, the
hammer and anvil are brought into violent contact.
With a two way drilling jar the second tubular member is
capable of both an upstroke and a downstroke from a central
starting position. The first tubular member has two anvils;
a first anvil positioned at the end of the upstroke and a
second anvil positioned at the end of the downstroke. The
2 1 8620 1
second tubular member has two hammers, a first hammer which
impacts against the first anvil at the end of the upstroke and
a second hammer which impacts against the second anvil at the
end of the downstroke.
A hydraulic drilling jar has a valve member that is
positioned in a fluid ch~her. The fluid chamber has a
restriction just large enough to accommodate the valve member.
When the restriction is encountered, the valve member becomes
lodged within the restriction, until sufficient hydraulic fluid
bleeds past via one or more bypass passages. The advantage
this provides is that a time delay is created prior to the
violent jarring impact of the hammer and anvil occurring. The
key to the operation of an hydraulic drilling jar is the
configuration of the valve member.
SU~ARY OF THE INVENTION
20The present invention relates to a two way hydraulic
drilling jar with an unique valve member.
According to one aspect of the present invention there is
provided a valve for a two way hydraulic drilling jar which
includes a hollow cylindrical member having an exterior
surface, an interior surface, a first end and a second end.
At least one spiral-form fluid bypass passage is positioned in
each of the first end and the second end of the cylindrical
member. The at least one spiral-form bypass passages has a
first end communicating with the exterior surface and a second
end communicating with the interior surface.
According to another aspect of the present invention there
is provided a two way hydraulic drilling jar which includes a
first tubular member and a second tubular member. The first
tubular member has an exterior surface and an interior surface
that defines an interior bore. The interior surface of the
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first tubular member has a first impact surface and a second
impact surface in spaced relation. The second tubular member
has an exterior surface and an interior surface that defines
an interior bore. The second tubular member is telescopically
received within the interior bore of the first tubular member.
The exterior surface of the second tubular member has a first
impact surface and a second impact surface. The second tubular
member is capable of limited axial movement relative to the
first tubular member. Upon relative movement in a first
direction the first impact surface of the second tubular member
and the first impact surface of the first tubular member are
brought into violent jarring contact. Upon relative movement
in a second direction the second impact surface of the second
tubular member and the second impact surface of the first
tubular member are brought into violent jarring contact. An
annular fluid chamber is positioned between the interior
surface of the first tubular member and the exterior surface
of the second tubular member. The fluid chamber has a first
end and a second end. Means is provided to seal the first end
and the second end of the fluid chamber. The fluid chamber has
a restriction intermediate the first end and the second end.
A hollow cylindrical member is disposed in the annular fluid
chamber and sized to pass through the restriction. The
cylindrical member has an exterior surface, an interior
surface, a first end and a second end. At least one spiral-
form fluid bypass passage is positioned in each of the first
end and the second end of the cylindrical member. The at least
one spiral-form bypass passage has a first end communicating
with the exterior surface and a second end communicating with
the interior surface. The cylindrical member is mounted to one
of first tubular member and the second tubular member with a
first contact surface engaging the first end and a second
contact surface engaging the second end. The cylindrical
member restricts the flow of hydraulic fluid when positioned
in the restriction such that relative movement of the first
tubular member and the second tubular member can only occur
once sufficient hydraulic fluid has bypassed the restriction.
21 8620 1
Hydraulic fluid bypasses the restriction by entering from the
exterior of the cylindrical member into the first end of one
of the at least one spiral-form bypass passage at one of the
first end and the second end of the cylindrical member, passing
along said at least one spiral-form bypas~ passage to the
interior of the cylindrical member. Hydraulic fluid enters
from the interior of the cylindrical member into the second end
of the at least one spiral-form bypass passage at the other of
the first end and the second end, and passes along said at
least one spiral-form bypass passage to the exterior of the
cylindrical member.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more
apparent from the following description in which reference is
made to the appended drawings, wherein:
FIGURE 1 is a side elevation view, in section, of a two
way hydraulic drilling jar constructed in accordance with the
teachings of the present invention, the Figure is divided into
two halves along a center line with a top half in an upstroke
impact position and a bottom half in a down stroke impact
position.
FIGURE 2 is a detailed side elevation view of a valve
portion of the two way hydraulic drilling jar illustrated in
FIGURE 1.
FIGURE 3 is a transverse section view taken along section
lines A-A adjacent one end of a valve portion of the two way
hydraulic drilling jar illustrated in FIGURE 2.
FIGURE 4 is a partially cut away perspective view of a
simplified embodiment of a valve for use in a two way hydraulic
drilling jar constructed in accordance with the teachings of
the present invention.
DE~TT~n DESCRIPTION OF THE ~K~KK~ EMBODIMENT
2186201
The preferred embodiment, a valve for a two way hydraulic
drilling jar generally identified by reference numeral 10, will
now be described with reference to FIGURES 1 through 4.
Referring to FIGURE 4, valve 10 includes a hollow
cylindrical member 12 having an exterior surface 14, an
interior surface 16, a first end 18 and a second end 20. At
least one spiral-form fluid bypass passage 22 is positioned in
each of first end 18 and second end 20 of cylindrical member
12. In FIGURE 4, which is a simplified version, two fluid
bypass passages 22 are illustrated to demonstrate the
underlying principle. In FIGURE 3, multiple fluid bypass
passages 22 are provided. Referring to FIGURE 4, each of
spiral-form bypass passages 22 has a first end 24 communicating
with exterior surface 14 and a second end 26 communicating with
interior surface 16. Exterior surface 14 of cylindrical member
12 has seal grooves 28. Referring to FIGURE 2, elastomer seals
30 are positioned in seal grooves 28.
Referring to FIGURE 1, valve 10 is intended for
incorporation in a two way hydraulic drilling jar, generally
identified by reference numeral 32. The primary components of
two way drilling jar 32 are a first tubular member 34 and a
second tubular member 36. First tubular member 34 has an
exterior surface 38 and an interior surface 40 that defines an
interior bore 42. Interior surface 40 of first tubular member
34 has a first impact surface or anvil 44 and a second impact
surface or anvil 46 positioned in spaced relation. For ease of
assembly, first tubular member 34 is made out of a number of
axially aligned sections 34a, 34b, 34c, 34d, 34e, and 34f.
Each of the described sections are connected at threaded
connections 48. Second tubular member 36 has an exterior
surface 50 and an interior surface 52 that defines an interior
bore 54. Second tubular member 36 is telescopically received
within interior bore 42 of first tubular member 34. Exterior
surface 50 of second tubular member 36 has a first impact
surface or hammer 56 and a second impact surface or hammer 58.
- 2186201
Second tubular member 36 is capable of limited axial movement
relative to first tubular member 34, this has been illustrated
in FIGURE 1 by showing second tubular member 36 in two
positioned relative to first tubular member 34. Upon relative
movement in a first direction first hammer 56 of second tubular
member 36 and first anvil 44 of first tubular member 34 are
brought into violent ~arring contact. Upon relative movement
in a second direction second hammer 58 of second tubular member
36 and second anvil 46 of first tubular member 34 are brought
into violent jarring contact. For ease of assembly second
tubular member 36 is made out of a number of axially aligned
sections 36a, 36b, and 36c. Each of the described sections are
connected at threaded connections 60. Two annular fluid
chambers 62 and 63 are positioned between interior surface 40
of first tubular member 34 and exterior surface 50 of second
tubular member 36. Fluid chamber 62 has a first end 64 and a
second end 66. A first seal assembly 68 is positioned at first
end 64 of chamber 62. A second seal assembly 69 is positioned
at second end 66 of chamber 62. First seal assembly 68
consists of a plurality of seal grooves 70 in which are
disposed elastomer seals 72. Second seal assembly 69 includes
a floating piston 74. Floating piston 74 has an interior
surface 76 and an exterior surface 78. Both interior surface
76 and exterior surface 78 have seal grooves 80 in which are
disposed elastomer seals 82. Fluid chamber 63 has a first end
71 and a second end 73. A first seal assembly 75 is positioned
at first end 71, consisting of a plurality of seal grooves 77
in which are disposed elastomer seals 79. A second seal
assembly 79 is positioned at second end 73. Second seal
assembly 79 includes a knocker piston 81. Knocker piston 81
has an interior surface 83 and an exterior surface 85. Both
interior surface 83 and exterior surface 85 have seal grooves
87 in which are disposed elastomer seals 89. Positioned between
fluid ch~mher 62 and fluid chamber 63 is a chamber 39 through
which drilling fluid can enter into the tool by radial access
openings 35. When drilling fluids are pumped down from surface
pumps and pass from interior bore 54 of second tubular member
7 21 86201
36. Fluid pressure is exerted upon floating piston 74, and
floating piston 74 moves in response to such pressure. As
drilling fluids pass back up the annulus along exterior surface
38 of first tubular member 34, the drilling fluids enter
5 chamber 39 through access openings 35. Knocker piston 81 also
moves in reponse to pressure exerted by the drilling fluids.
This movement of pistons 74 and 81, reduces back pressure on
second tubular member 36. Fluid chamber 62 has a restriction
84 positioned intermediate first end 64 and second end 66.
Hollow cylindrical member 12 of valve 10 is disposed in annular
fluid chamber 62. Cylindrical member 12 is mounted to second
tubular member 36 and moves with second tubular member 36.
Referring to FIGURE 3, in the seating position for cylindrical
member 12, second tubular member 36 has a series of milled
flats which serve as undercut fluid flow channels 37 permitting
the passage of fluids between second tubular member 36 and
interior surface 16 of valve member 10. Referring to FIGURE
2, after assembly, a first contact surface 86 engages first end
18 and a second contact surface 88 engages second end 20 of
cylindrical member 12. In the illustrated embodiment, first
contact surface 86 is provided by a shoulder projecting
outwardly from exterior surface 50 of second tubular member 36.
Second contact surface 88 is provided by an annular sleeve 90
that is biased by a spring 91 into engagement with second end
25 20 of cylindrical member 12. Interior surface 92 of annular
sleeve 90 has several seal grooves 94 in which are positioned
elastomer seals 96 in order to prevent leakage. Cylindrical
member is sized to just barely pass through restriction 84.
This is made easier by the presence of elastomer seals 30 on
30 exterior surface 14 of cylindrical member 12. Metal expands
and contracts when it is subjected to heat. In the prior art
valves, problems been experienced with the valves expanding
when heated and becoming jammed in the restriction. When the
valves are modified to prevent jamming the valves have passed
35 through the restrictions too easily. Elastomer seals 30 on
cylindrical body 12 of valve 10 are preferred as they enable
cylindrical member 12 to prevent the flow of hydraulic fluid
'- 21 86201
through restriction 84, without risk of cylindrical member 12
becoming jammed in restriction 84. With cylindrical member 12
restricting the flow of hydraulic fluid through restriction 84,
relative movement of first tubular member 34 and second tubular
member 36 can only occur once sufficient hydraulic fluid has
bypassed restriction 84 by bleeding through spiral-form bypass
passages 22. In order to ensure that particulate matter does
not clog bypass passages 22, a filter 98 is positioned at first
end 24 of the spiral-form bypass passages 22 which catches
particulate contaminants before they can enter spiral-form
bypass passages 22. A drilling jar can be operated in an
unlocked position in which there can be movement, however, it
is preferred that the drilling jar be kept in the locked
position. The preferred manner of locking an hydraulic
drilling jar is by means of a mechanical latch. Referring to
FIGURE 1, a mechanical latch 100 is, therefore, provided with
a first clutch engagement 102 secured to first tubular member
34 and a second clutch engagement 104 secured to second tubular
member 36. In a particular relative telescopic position,
clutch engagement 102 and clutch engagement 104 interlock to
place two way hydraulic drilling jar 32 in a locked position.
The use of valve member 10 in the operation of two way
hydraulic drilling jar 32 will now be described. Hydraulic
drilling jar 32 is operated with mechanical latch 100 in an
engaged position. When jarring is required, hydraulic drilling
jar 32 is placed in tension, thereby releasing mechanical latch
100 and leaving the drilling jar 32 operating on a purely
hydraulic basis. The release pressure depends upon size. For
example in a 6 1/2 inch diameter tool, mechanical latch 100 is
typically set so that a force of 20,000 to 30,000 pound is
required to trigger its release. Cylindrical member 12 is
moved into restriction 84, in preparation for either a jarring
upstroke or a jarring downstroke. With the flow of hydraulic
fluids through restriction 84 precluded by cylindrical member
12, relative movement of first tubular member 34 and second
tubular member 36 can only occur once sufficient hydraulic
9 2 1 8620 1
fluid has bypassed restriction 84. Hydraulic drilling jar is
then placed in tension so that there is a force build up that
will be released as soon as valve 10 moves out of restriction
84. For example with a 6 1/2 inch tool, the force placed upon
5 the tool, typically, will be 60,000 or 70,000 pounds with a
time delay of 45 to 60 seconds. The time delay can be altered,
however, by changing the width and length of spiral-form fluid
bypass passages 22. There is a difference in force required for
an upstroke and a downstroke. On the upstroke, the force of
the hydrostatic head must be overcome, which may add an
additional 30,000 pounds to the force exerted. The fluids
bypass restriction 84 by entering through filters 98 from
exterior 14 of cylindrical member 12 into first end 24 of
spiral-form bypass passages 22. Whether hydraulic fluids enter
15 from first end 18 or second end 20 of cylindrical member 12
depends upon whether an upstroke or a downstroke is being
attempted. After entering first end 24 of spiral-form bypass
passages 22, the hydraulic fluid passes along the bypass
passages 22 exiting out second end 26 to interior surface 16
20 of cylindrical member 12. From interior surface 16 of
cylindrical member 12, the hydraulic fluid passes along
undercut fluid flow channel 37 and then into second end 24 of
spiral-form bypass passages 22 at the other of first end 18 and
second end 20 of cylindrical member 12. The hydraulic fluids
25 then passes along spiral-form bypass passages 22 exiting filter
98 to exterior 14 of cylindrical member 12, having thereby
bypassed restriction 84. In this manner cylindrical member 12
gradually moves out of restriction 84. As soon as cylindrical
member 12 is no longer blocking the flow of hydraulic fluids
through restriction 84, relative movement of first tubular
member 34 and second tubular member 36 can occur. If the
relative movement is in a first direction, first hammer 56 of
second tubular member 36 and first anvil 44 of first tubular
member 34 are brought into violent jarring contact. If the
35 relative movement is in a second direction second hammer 58 of
second tubular member 36 and second anvil 46 of first tubular
member 34 are brought into violent jarring contact.
- lO 2~86201
Valve 10 with its spiral-form bypass passages 22, as
described, provides a number of advantages over other forms of
valves when positioned in two way drilling jar 32. Unlike other
valves that rely upon metal to metal seals, valve 10 is not
temperature sensitive. A change in the time delay may be
effected merely by changing the size and length of spiral-form
bypass passages 22. The positioning of the filtering elements
98 prevents plugging of spiral-form bypass passages 22. They
tend to be self cleaning as liquids flow through filtering
elements 98 in one direction with an upstroke and in the
opposite direction with a downstroke.
It will be apparent to one skilled in the art that
modifications may be made to the illustrated embodiment without
departing from the spirit and scope of the invention as
hereinafter defined in the Claims.
