U.S. patent application number 11/479022 was filed with the patent office on 2007-01-25 for downhole multi-action jetting tool.
Invention is credited to Howard L. McGill, John C. Wolf.
Application Number | 20070017679 11/479022 |
Document ID | / |
Family ID | 37604804 |
Filed Date | 2007-01-25 |
United States Patent
Application |
20070017679 |
Kind Code |
A1 |
Wolf; John C. ; et
al. |
January 25, 2007 |
Downhole multi-action jetting tool
Abstract
An apparatus for cleaning a wellbore casing includes an outer
housing having an axial through passage between an inlet and a
first outlet wherein the inlet and the first outlet are adapted for
connection in a work string, the outer housing having a second
outlet extending in a direction generally transversely of the
through passage, an index mandrel slidably located within the outer
housing and having an axial bore extending therethrough, the index
mandrel being movable relative to the outer housing between a first
position in which the second outlet is closed and a second position
in which the second outlet is open, a ball seat located on an upper
end of the index mandrel, a spring located within the outer housing
and biasing the index mandrel toward the first position, a ball
retainable on the ball seat to prevent flow from the inlet to the
first outlet, and wherein application of a first pressure on the
ball forces the index mandrel against the spring into the second
position and reduction of said first pressure permits return of the
index mandrel to the second position.
Inventors: |
Wolf; John C.; (Houston,
TX) ; McGill; Howard L.; (Lufkin, TX) |
Correspondence
Address: |
CARTER J. WHITE LEGAL DEPARTMENT;M-I L.L.C.
5950 NORTH COURSE DRIVE
HOUSTON
TX
77072
US
|
Family ID: |
37604804 |
Appl. No.: |
11/479022 |
Filed: |
June 30, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60695828 |
Jun 30, 2005 |
|
|
|
Current U.S.
Class: |
166/312 ;
166/174 |
Current CPC
Class: |
E21B 34/14 20130101;
E21B 37/00 20130101; E21B 23/006 20130101 |
Class at
Publication: |
166/312 ;
166/174 |
International
Class: |
E21B 37/00 20060101
E21B037/00 |
Claims
1. An apparatus for cleaning a wellbore casing comprising: an outer
housing having an axial through passage between an inlet and a
first outlet wherein the inlet and the first outlet are adapted for
connection in a work string, the outer housing having a second
outlet extending in a direction generally transversely of the
through passage; an index mandrel slidably located within the outer
housing and having an axial bore extending therethrough, the index
mandrel being movable relative to the outer housing between a first
position in which the second outlet is closed and a second position
in which the second outlet is open; a ball seat located on an upper
end of the index mandrel; a spring located within the outer housing
and biasing the index mandrel toward the first position; a ball
retainable on the ball seat to prevent flow from the inlet to the
first outlet; and wherein application of a first pressure on the
ball forces the index mandrel against the spring into the second
position and reduction of said first pressure permits return of the
index mandrel to the second position.
2. The apparatus of claim 1, further comprising: an indexing pin
retained on an inner surface of the outer housing; wherein the
index mandrel has an indexing groove in an outer surface; and
wherein the indexing pin cooperates with the indexing groove to
position the index mandrel in the first position and the second
position.
3. The apparatus of claim 2, wherein the index mandrel has a third
position, between the first position and the second position, in
which the second outlet is closed.
4. The apparatus of claim 1, further comprising: a jet housing
around the outer housing, the jet housing including a plurality of
nozzles in fluid communication with the second outlet and
positioned to direct fluid received from the second outlet in a
direction substantially perpendicular to the axial through
passage.
5. The apparatus of claim 4, wherein the jet housing further
comprises: a plurality of nozzles in fluid communication with the
second outlet and positioned to direct fluid received from the
second outlet in a direction substantially tangent to the jet
housing.
6. The apparatus of claim 5, wherein the jet housing is rotatable
about the outer housing.
7. The apparatus of claim 1, wherein the ball is deformable to be
pushed through the ball seat and discharged through the first
outlet.
8. The apparatus of claim 1, further comprising: a ball catcher sub
positioned below the outer housing, the ball catcher sub
comprising: a ball catcher housing having a ball catcher axial
through passage between a ball catcher inlet and a ball catcher
outlet wherein the ball catcher inlet and the ball catcher outlet
are adapted for connection in a work string; a trap finger
pivotally retained within the ball catcher housing, wherein the
trap finger is pivotable to receive the ball when discharged from
the first outlet; a ball catcher tube retained within the ball
housing and having a length and an inner diameter sufficient to
hold a plurality of balls; and wherein an annulus is formed between
the ball catcher tube and the ball catcher housing sufficient for
fluid to be communicated through the ball catcher sub.
9. The apparatus of claim 8, wherein the trap finger pivots
downward to receive the ball within the ball catcher tube and
cannot pivot upwards, thereby preventing the ball from escaping the
ball catcher tube when fluid is reverse circulated through the
axial through passage.
10. The apparatus of claim 8, wherein the ball catcher tube has a
plurality of holes therein to communicate fluid from the ball
catcher tube to the annulus.
11. A method of cleaning an inner surface of a casing in a wellbore
comprising: lowering a jetting tool on a work string into the
wellbore to a desired location, wherein the jetting tool has an
outer housing with an axial through passage between an inlet and a
first outlet, the outer housing also having a second outlet
substantially transverse to the axial through passage, and an index
housing slidingly retained within the outer housing in a first
position such that the second outlet is closed, the index housing
having a ball seat on an upper end and being biased toward the
first position; dropping a ball into the axial through passage to
rest on the ball seat, thereby preventing fluid flow between the
inlet and the first outlet of the axial through passage, causing
fluid pressure to force the index housing to a second position
wherein the second outlet is open; circulating fluid from the axial
through passage and the second outlet at a fluid pressure
sufficient to clean the casing; decreasing the fluid pressure to
return the index housing to the first position; increasing the
fluid pressure to move the index housing to a third position
wherein the second outlet is closed; and wherein the increased
fluid pressure is sufficient to shear the ball from the ball seat,
thereby reducing the fluid pressure on the index housing causing it
to return to the first position.
12. The method of claim 11, further comprising: rotating the
jetting tool while circulating the fluid to direct the circulating
fluid circumferentially around the inner surface of the casing.
13. The method of claim 12, further comprising: raising and
lowering the jetting tool in the wellbore while circulating the
fluid to clean a longitudinal area of the inner surface of the
casing.
14. The method of claim 13, further comprising: positioning the
jetting tool within the blowout preventor; and circulating the
fluid from the axial through passage and the second outlet at a
fluid pressure sufficient to clean the blowout preventor.
15. The method of claim 11, further comprising: catching the ball
in a ball catcher located below the index housing.
16. The method of claim 15, further comprising: reverse circulating
the fluid through the axial through passage; and retaining the ball
in the ball catcher with a trap finger during reverse
circulation.
17. A method of opening and closing an outlet through a side of a
cylindrical outer housing of a jetting tool in a wellbore, the
method comprising: biasing the index housing to an upward position
within the outer housing in which the index housing is blocking the
fluid outlet through the side of the outer housing; dropping a ball
to seal against a ball seat located at the upper end of the index
housing and block fluid flow through the jetting tool; forcing the
index housing to a lower position inside the outer housing as a
result of increased pressure behind the ball, wherein the fluid
outlet through the side of the outer housing is open; reducing the
fluid pressure on the ball to permit the biasing of the index
housing towards the upward position, wherein the fluid outlet
through the side of the outer housing is closed; and increasing the
fluid pressure on the ball to a pressure sufficient to shear the
ball through the ball seat, thereby permitting the index housing to
return to the upward position.
18. The method of claim 17, wherein the fluid pressure is increased
and decreased a quantity of times to open and close the fluid
outlet through the side of the outer housing before increasing the
fluid pressure sufficient to shear the ball.
19. The method of claim 18, further comprising: dropping a second
ball after shearing the first ball to seal against the ball seat
and block fluid flow through the jetting tool; repeating the
forcing, repeating, and increasing steps.
Description
[0001] This application claims priority to Provisional Patent
Application 60/695,828 filed on Jun. 30, 2005 and entitled,
"Downhole Bypass Valve" the contents of which are incorporated
herein by reference for all purposes. New matter has been
added.
BACKGROUND OF INVENTION
[0002] A wellbore may be drilled in the earth for various purposes,
such as hydrocarbon extraction, geothermal energy, or water. After
a wellbore is drilled, the wellore is typically lined with casing.
The casing preserves the shape of the wellore as well as provides a
sealed conduit for fluid to be transported to the surface.
[0003] In general, it is desirable to maintain a clean wellore to
prevent possible complications that may occur from debris in the
wellore. For example, accumulation of debris can prevent free
movement of tools through the wellore during operations, as well as
possibly interfere with production of hydrocarbons or damage tools.
Potential debris includes cuttings produced from the drilling of
the wellore, metallic debris from the various tools and components
used in operations, and corrosion of the casing. Much of this
debris may be removed by increasing the annular fluid velocity to
bring larger particles to the surface of the wellbore.
[0004] However, over time, the casing or liner within the wellbore
becomes covered with hard deposits. These deposits must be
periodically removed or they can build up to levels of thickness
and hardness where they can adversely affect efficient operation of
the oil well.
[0005] Many tools operate continuously through a wellbore, for
example scrapers and brushes. While it is useful to have such
continuous use tools, it is often beneficial to have tools that are
selectively operable when the tool has reached a preferred location
in the wellbore.
[0006] Cleaning involves spraying or jetting the inner wall of the
casing with cleaning fluid at very high pressure to break up and
dislodge the deposited material. A cleaning device having side
jetting nozzles is lowered into the wellbore casing on the end of a
drill string. Once a section of the wellbore casing has been jet
cleaned, the cleaning device is withdrawn from the wellbore casing
and removed from the end of the string. The drill string is then
returned to the wellbore casing and cleaning fluid is run through
the casing to a point below the section of the wellbore casing that
was jet cleaned. The cleaning fluid circulates upward through the
annulus between the wellbore casing and the drill string, carrying
material dislodged during the jetting operation to the top of the
wellbore casing. This operation of jetting and flushing is repeated
as necessary to clean the wellbore casing of deposited material.
Many cleaning and jetting tools use multiple balls to actuate and
de-actuate the tool. It would be an improvement to have a cleaning
tool that can be actuated and de-actuated without the need to use
multiple balls.
SUMMARY
[0007] In one aspect, the disclosed invention relates to an
apparatus for cleaning a wellbore casing including an outer housing
having an axial through passage between an inlet and a first outlet
wherein the inlet and the first outlet are adapted for connection
in a work string, the outer housing having a second outlet
extending in a direction generally transversely of the through
passage, an index mandrel slidably located within the outer housing
and having an axial bore extending therethrough, the index mandrel
being movable relative to the outer housing between a first
position in which the second outlet is closed and a second position
in which the second outlet is open, a ball seat located on an upper
end of the index mandrel, a spring located within the outer housing
and biasing the index mandrel toward the first position, a ball
retainable on the ball seat to prevent flow from the inlet to the
first outlet, and wherein application of a first pressure on the
ball forces the index mandrel against the spring into the second
position and reduction of said first pressure permits return of the
index mandrel to the second position.
[0008] In another disclosed embodiment of the invention, a method
of cleaning an inner surface of a casing in a wellbore includes
lowering a jetting tool on a work string into the wellbore to a
desired location, wherein the jetting tool has an outer housing
with an axial through passage between an inlet and a first outlet,
the outer housing also having a second outlet substantially
transverse to the axial through passage, and an index housing
slidingly retained within the outer housing in a first position
such that the second outlet is closed, the index housing having a
ball seat on an upper end and being biased toward the first
position, dropping a ball into the axial through passage to rest on
the ball seat, thereby preventing fluid flow between the inlet and
the first outlet of the axial through passage, causing fluid
pressure to force the index housing to a second position wherein
the second outlet is open, circulating fluid from the axial through
passage and the second outlet at a fluid pressure sufficient to
clean the casing, decreasing the fluid pressure to return the index
housing to the first position, increasing the fluid pressure to
move the index housing to a third position wherein the second
outlet is closed, and wherein the increased fluid pressure is
sufficient to shear the ball from the ball seat, thereby reducing
the fluid pressure on the index housing causing it to return to the
first position.
[0009] In another embodiment of the disclosed invention, a method
of opening and closing an outlet through a side of a cylindrical
outer housing of a jetting tool in a wellbore includes biasing the
index housing to an upward position within the outer housing in
which the index housing is blocking the fluid outlet through the
side of the outer housing, dropping a ball to seal against a ball
seat located at the upper end of the index housing and block fluid
flow through the jetting tool, forcing the index housing to a lower
position inside the outer housing as a result of increased pressure
behind the ball, wherein the fluid outlet through the side of the
outer housing is open, reducing the fluid pressure on the ball to
permit the biasing of the index housing towards the upward
position, wherein the fluid outlet through the side of the outer
housing is closed, and increasing the fluid pressure on the ball to
a pressure sufficient to shear the ball through the ball seat,
thereby permitting the index housing to return to the upward
position.
[0010] Other aspects and advantages of the claimed subject matter
will be apparent from the following description and the appended
claims.
DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a cross-sectional view of an embodiment of a well
cleaning tool.
[0012] FIG. 2 is a front view of an embodiment of a well cleaning
tool.
[0013] FIG. 3 is a detail cross sectional view of an embodiment of
a well cleaning tool.
[0014] FIG. 4 is a layout of an embodiment of an indexing
groove.
[0015] FIG. 5 is a schematic of a well cleaning tool in a first,
run-in-hole, position.
[0016] FIG. 6 is a schematic of a well cleaning tool in a second,
jetting, position.
[0017] FIG. 7 is a schematic of a well cleaning tool in a third,
intermediate, position.
[0018] FIG. 8 is a schematic of a well cleaning tool in a fourth,
ball shear, position.
[0019] FIG. 9 is a partial cross sectional view of the downhole
bypass valve in a first run in position.
[0020] FIG. 10a is a partial cross sectional view of the indexing
pin and surrounding components.
[0021] FIG. 10b is a partial cross sectional view of a port and a
bonded seal member.
[0022] FIG. 10c is a partial cross sectional view of a collet
assembly.
[0023] FIG. 11 is a partial cross sectional view of the downhole
bypass valve in the first position with the ball actuator.
[0024] FIG. 12 is a partial cross sectional view of the downhole
bypass valve in a second position.
[0025] FIG. 13 is a partial cross sectional view of the downhole
bypass valve in a third position.
[0026] FIG. 14 is a partial cross sectional view of the downhole
bypass valve in a fourth position.
[0027] FIG. 15 is a layout of the indexing groove.
DETAILED DESCRIPTION
[0028] Referring to FIGS. 1 and 2, a downhole jetting tool 100 that
may be used to selectively divert fluid that is flowing down the
drill string bore 102 to the annulus 104 between the drill string
and the casing 106 of a wellbore 108. The jetting tool 100 includes
an outer housing 110 and a spring-loaded index mandrel 168 defining
a tubular assembly having an inlet 206 and a first outlet 208.
[0029] The outer housing 110 defines an axial through passage 124
within which the index housing 168 is located. The outer housing
110 has a top sub 126 provided at a top end 112, wherein the top
sub 126 includes a threaded box 114 to couple to an upper drill
string component (not shown). The top sub 126 has one or more
radially extending ports 132 extending from the axial through
passage 124 to the annulus 104, collectively defining a second
outlet 128. The top sub 126 is coupled to a swivel housing 116 for
the index housing 168 at a lower end 130. The coupling of the
swivel housing 134 and the top sub 126 provides an upper shoulder
138 at the lower end 136 of the top sub 126. A lower shoulder 140,
formed in the swivel housing 116, is spaced apart from the upper
shoulder 136 to form an inner recess 142 within which a swivel ring
144 is retained. The swivel ring 144 includes at least one indexing
pin 146 extending radially into the axial through passage 124
defined by the outer housing 110. While the swivel ring 144 is
axially retained by the upper and lower shoulders 138, 140, the
swivel ring 144 is not rotationally retained to the outer housing
110. Thus, the swivel ring 144 may rotate within the confines of
the upper and lower shoulders 138, 140. Along a middle portion 150
of the swivel housing 116, a spring housing 152 is coupled thereto.
A lower portion 154 of the swivel housing 116 protrudes axially
within a through bore 156 defined by the spring housing 152. The
lower portion 154 of the swivel housing 116 is spaced apart from
the corresponding portion of the spring housing 152 such that a
small gap 162 is created. Within this small gap 162, a spring
sleeve 162 is coupled to the spring housing 152. As will be
explained below, the spring sleeve 164 is included primarily to aid
in the assembly and disassembly of the jetting tool 100. The spring
housing 152 is provided with external threads 120 at lower end 118
to coupled to a ball catcher 122 or another lower drill string
component (not shown).
[0030] As previously stated, the index housing 168 is located
within the outer housing 110. The index housing 168 includes an
indexing mandrel 170 coupled at a lower end 172 to a collet blank
174 to define a mandrel through passage 176. The through passage
176 has a mandrel bore radius 178. The indexing mandrel 170 has a
ball seat 148 sealingly coupled at a top end 158. An o-ring 166 may
be included to seal the interface between the ball seat 148 and the
index mandrel 170. Other sealing means known in the art may be
used. The ball seat 148 includes a lower shoulder 186, which rests
against top end 158. A frustroconical section 188 at the top of the
ball seat 148 provides a guide to direct a ball 250 (the ball 250
and related features are shown in FIGS. 5-8) through the center of
the through passage. A landing section 190 projects generally
inward at the bottom 194 of the ball seat 148. The landing section
190 projects inward a sufficient distance and angle to seat the
ball 250 as will be described. The radius 240 of the landing
section 190 is thus smaller than the ball radius 252. A seal member
180 is located above a shoulder formation 182 in the outer surface
184 of the indexing mandrel 170 and below the lower shoulder 186 of
the ball seat 148. Below the shoulder formation 182, a recess 202
is formed in the outer surface 184 of the indexing mandrel 170. An
o-ring 204 or other sealing member seals the interface between the
outer surface 184 of the indexing mandrel 170 and the inner surface
192 of the top sub 126 below the recess 202.
[0031] An indexing groove 200 is formed into the outer surface 184
of the indexing mandrel 170 between the o-ring 204 and a lower end
172 of the indexing mandrel 170. The indexing pin 146, coupled to
the outer housing 110, is positioned within the indexing groove
200. The function of the indexing groove 200 and the indexing pin
146 is described in greater detail below.
[0032] A spring assembly 210 includes the collet blank 174, a
spring follower 214 and a spring 216. As was previously described,
the collet blank 174 couples to the index mandrel 170. The spring
216 is located within the through passage 156 defined by the spring
housing 152. A shoulder formation 218 in the inner surface 220 of
the spring housing 152 near the lower end 118 provides support to a
lower end 222 of the spring 216. The spring follower 214 has a
lower shoulder 224 that is seated atop an upper end 226 of the
spring 216. The collet blank 174 has a lower end 228 that is seated
atop an inner shoulder 230 of the spring follower 214 such that the
lower end 228 of the collet blank 174 is within the spring follower
214.
[0033] The ball 250 will be used to actuate the jetting tool 100.
The ball 250 will be dropped from the top of the work string and
allowed to float downward through the fluid in the axial through
passage 124 until it reaches the ball seat 148. Thus, the ball 250
is formed from a material having a specific gravity greater than
fluid though which it will be dropped. Further, the ball 250 must
be made from a material that will not be degraded by the chemical
composition of the fluid in axial though passage 102. Also, when
the jetting tool 100 no longer needs to be cycled, the ball 250 can
be sheared through the ball seat 148 by increasing the fluid
pressure through the axial through passage 102. Thus, the ball 250
is also formed from a material that will deform under a
predetermined minimum pressure. For example, in one embodiment, the
ball is made from a thermoplastic polyester based on polyethylene
terephthalate, such as ERTALYTE (.TM.).
[0034] When the jetting tool 100 is assembled, the spring 216 is
lowered into the spring housing 152 and the spring follower 214 is
placed atop the spring 216. The swivel housing 116 couples to the
spring housing 152. However, the length of the spring 216 when
loaded only with the spring follower 214 would extend beyond the
lower end 160 of the lower portion 154 of the swivel housing 134
when the swivel housing 116 is coupled to the spring housing 152.
Instead of loading the spring 216 with the swivel housing 116 while
coupling to the spring housing 152, the spring sleeve 164 is
coupled to the spring housing 152 to preload the spring 216,
through the spring follower 214, against a lower shoulder 166. The
smaller size of the spring sleeve 164 makes it easier to couple to
the spring housing 152 while simultaneously preloading the spring
216. The larger swivel housing 134 may then be simply coupled to
the spring housing 152. When disassembling the jetting tool 100,
the spring sleeve 164 retains the spring 162 and spring follower
214 within the spring housing 152 while the swivel housing 116 is
removed.
[0035] In one embodiment a jetting housing 196 is provided around
the bypass valve 100. The jetting housing 196 displaces annular
space when the bypass valve 100 is to be used in a bore, such as
that of a riser, having a sufficiently large inner diameter that
annular fluid velocity would be lost if the jetting tool 100 were
used without the jetting housing 196. By reducing the annular area,
fluid velocity through the second outlet 132 into the annulus 104
may be maintained at a rate that is effective for removing debris
or circulating fluid. Jetting housings 196 having different outer
diameters may be available and the choice of size is typically
based upon the diameter of the casing to be cleaned. Referring to
FIGS. 2 and 3, the jetting housing 196 includes a plurality of
jetting ports 198. When the second outlet 128 is open, the jetting
ports 198 focus a stream of fluid toward the casing 106 of the
wellbore 108 in a direction substantially perpendicular to the
axial through passage 124. As the fluid exits the jetting ports
198, the direction of the stream of fluid will be affected by fluid
circulation in the annulus 104 fluid pressure in the annulus 104,
as well as the geometry of the jetting port exits. While the fluid
is directed toward the casing 106, it will be appreciated by a
person of skill in the art that the fluid direction will not be
precisely pointed at a point on the casing, but rather a general
area of the casing 106. In one embodiment, the jetting housing 196
includes a plurality of tangent jetting ports 212, as can be seen
in FIG. 3. Tangent jetting ports 212 direct fluid flow in a
direction substantially tangent to the flow of fluid out of the
jetting ports 198. As with the jetting ports 198, fluid flow out of
the tangent jetting ports 212 is affected by a variety of factors
including fluid circulation in the annulus 104 fluid pressure in
the annulus 104, as well as the geometry of the tangent jetting
port exits. In one embodiment, the jetting housing 196 is
rotationally retained on the outer housing 110. In one embodiment,
tangent jetting ports 212 rotate the jetting housing 196 about the
outer housing 110.
[0036] When lowered downhole on the drill string, the jetting tool
100 is in a first position, as depicted in FIGS. 1 and 5. In this
position, the recess 202 of the indexing mandrel 170 is positioned
inside the second outlet 128. As depicted in FIG. 1, the seal ring
180 is located above the second outlet 128 while the o-ring 204 is
positioned below the second outlet 128 to prevent fluid
communication between the through passage 176 and the annulus 104.
Returning to FIGS. 1 and 5, fluid may continue to flow through the
through passage 176 defined by the index housing 168 and the
through passage 156 defined by the spring housing 152.
[0037] Referring to FIG. 6, when it is desired to actuate the
jetting tool 100, a ball 250 is dropped through the drill string
and circulated until it reaches the jetting tool 100. The ball 250
has a ball radius 252, which is less than the outer housing radius
232 and greater than the landing section radius 240, thus
permitting the ball 250 to continue to circulate through the
jetting tool 100 until it comes to rest atop the landing section
190. The ball 250 prevents further fluid flow through the bore 238,
156 of the index housing 168, spring 216, and spring housing 152.
As the fluid pressure is increased, the ball seat 148 and index
housing 168 are pushed downward against the upward force of the
spring 216. The indexing groove 200 on the indexing mandrel 170
interfaces with the indexing pin 146 to direct the position of the
indexing mandrel 170 within the outer housing 110.
[0038] The indexing groove path 262 is depicted in FIG. 4. When the
jetting tool 100 is in the first position, the indexing pin 146 is
located in a first groove location 260. Referring to FIG. 6, after
the ball 250 is seated on the ball seat 148, fluid pressure is
increased until the ball seat 148 and indexing mandrel 170 are
driven downward against the force of the spring 216. As the
indexing mandrel 170 moves downward within the outer housing 110,
the indexing pin 146 follows the indexing groove path 262 until it
has reached a first groove wall 264. Upon contacting the first
groove wall 264, the indexing pin 146 continues a path parallel to
the first groove wall 264 until it has shouldered against second
groove location 266. The outer housing 110 is rotationally fixed by
the drill string. The swivel ring 144 is rotated within the outer
housing 110 as the indexing pin 146 follows the indexing groove
path 262. When the indexing pin 146 is shouldered against the
second groove location 266, the jetting tool 100 is in a
corresponding second position, shown in FIG. 6.
[0039] In the second position, the ball 250 remains seated atop the
landing section 190 of the ball seat 148. The indexing mandrel 170
and ball seat 148 have moved a sufficient distance downward to open
the second outlet 128, providing fluid communication from the
through passage 124 to the annulus 104. So long as the fluid flow
remains sufficient to provide pressure to the ball 250 and the
index housing 168 to overcome the upward force of the spring 216,
the jetting tool 100 will remain in the second position.
[0040] Referring to FIGS. 6 and 7, when the flow drops to below a
predetermined flow rate corresponding to a predetermined fluid
pressure, the spring 216 will push the index housing 168 upward.
The indexing pin 146 continues to follow the indexing groove path
262 and contacts a second groove wall 268. The indexing pin 146
follows the incline of the second groove wall 268 to position the
indexing mandrel 170 within the outer housing 110. The indexing
mandrel 170 continues to move upward until the indexing pin 146
shoulders against a third groove location 270. When the indexing
pin 146 is in the third groove location 270, the jetting tool 100
is in a corresponding third position, shown in FIG. 7.
[0041] In the third position, the ball 250 remains seated atop the
landing section 190 of the ball seat 148. The second outlet 128 is
closed, resulting in no fluid communication from the through
passage 124 to the annulus 104 and no flow through the through
passage 124 to the first outlet 208.
[0042] The fluid pressure may be increased to cycle the indexing
mandrel 170 to a fourth position, in which the indexing pin 146 is
shouldered against a fourth groove location 272 longitudinally
located along the indexing mandrel 170 between the second groove
location 266 and the third groove location 270. So long as the
fluid pressure does not exceed a predetermined pressure sufficient
to deform the ball 250, decreasing the fluid pressure again will
return the indexing mandrel 168 to the third position, wherein the
indexing pin 146 is shouldered against another third groove
location 270. Increasing pressure when the ball 250 is in the third
position for the second time will return the indexing mandrel 170
to a second position in which the second outlet 128 is open. This
cycle may be continued until the indexing pin 146 has traversed the
indexing groove path 262 any number of times.
[0043] When the jetting operation is completed, the jetting tool
100 is cycled by increasing and decreasing fluid pressure on the
ball 250 until the indexing pin 146 is again in the fourth groove
location 272. The pressure may then be increased to a predetermined
pressure sufficient to shear the ball 250 through the bottom 194 of
the ball seat 148, as shown in FIG. 8. The ball 250 is then forced
downward through the through passage 238 of the index housing 168
and the through passage 156 of the spring housing 152. The ball 250
is caught in a downstream ball catcher 122. When the ball 250 is
released from the ball seat 148, the fluid pressure counteracting
the spring force is relieved and the spring 216 pushes the index
housing 168 and the ball seat 148 upward. The indexing groove 200
and pin 146 interact to reposition the indexing mandrel 170 in the
first position in which the second outlet 128 is closed and from
which the entire process may be performed again.
[0044] Referring to FIG. 1, the ball catcher 122 includes a ball
catcher sub 234 within which a ball catcher tube 236 is retained. A
trap finger 238 is provided near the top end 242 of the ball
catcher tube 236. The top end 242 of the ball catcher tube 236 may
be provided with slots 276. The trap finger 238 is pivotally
retained to the ball catcher tube 236 near the top end 242 along a
pivot edge 244. A torsion spring 246 biases the trap finger 238
toward a "closed" position. As shown in FIG. 1, a free edge 248 is
rotatable within the ball catcher sub 234. The trap finger 238 has
a length 254 such that the trap finger 238 free edge 248 can travel
through slot 276 and is caught on an edge of the slot 276 before
opening in an upward position. A stopper 178 may be included near
the free edge 248 to aid in catching the slot edge before
over-traveling. When the ball 250 is discharged from the ball seat
148, the ball 250 pushes the free edge 248 downward and enters the
ball tube 236. Once the ball 250 has cleared the trap finger 238,
the torsion spring 246 moves the trap finger 238 back to the closed
position.
[0045] The ball catcher tube 236 has an outer diameter less than
the inner diameter of the ball catcher sub 234, defining a ball
catcher annulus 274. The ball catcher tube 236 is also provided
with a number of holes 258 though the wall of the tube 236
providing fluid communication from the though passage of the ball
catcher tube 236 to the ball catcher annulus 274. If reverse
circulation is desired, the holes 258 and ball catcher annulus 274
allow fluid flow around any balls 250 retained in the ball catcher
tube 236 and to the tools above the ball catcher 122. Any balls 150
in the ball catcher tube 236 that are forced upward by the reverse
circulation are retained by the trap finger 238. Any force on the
trap finger 238 by retained balls 250 will reinforce the force of
the torsion spring 246 in pushing the free edge 248 against the
slot edge of the ball catcher tube 236, thereby preventing the loss
of balls 250 from the ball catcher 122. The ball catcher tube 236
may be sized to accommodate any number of balls 250. For example,
in one embodiment, the ball catcher tube 126 holds six balls
250.
[0046] The jetting tool 100 can be used to clean the inner surface
of a casing and/or a blowout preventor (BOP). To perform a cleaning
operation, the jetting tool 100 is assembled on a work string and
lowered into the wellbore 108 to a location to be cleaned. The
index housing 168 is in a first position relative to the outer
housing 110, as shown in FIG. 5, and the second outlet 128 through
the outer housing 110 is closed off by the index housing 168. The
ball 250 is dropped into the axial through passage 102 of the work
string and is circulated through the work string until the it
reaches the ball seat 148 of the jetting tool 100. When the ball
150 reaches the ball seat 128, it is directed to a landing section
190 where it prevents fluid from flowing through the index housing
168 and spring housing 152 as well as the lower work string tools
(not shown). Fluid continues to be pumped at a predetermined rate
into the through passage 102 of the work string, thereby applying
pressure to the ball 250. This pressure works against the upward
force of the spring 216. As the pressure on the ball 250 increases,
the index housing 168 is lowered relative to the outer housing 110
until the index housing 168 reaches a second position, shown in
FIG. 6. When the index housing 168 is in the second position, the
second outlet 128 through the outer housing 110 is open. The fluid
that is being pumped into the axial through passage is then
directed through the second outlet 128 and the jetting ports 198 at
a pressure sufficient to clean the casing and/or BOP. The jetting
tool 100 may be rotated by rotating the work string to direct fluid
flow from the jetting ports 198 at a circumferential area of the
casing or BOP. The jetting tool 100 may be raised and/or lowered by
raising and/or lowering the work string to direct flow from the
jetting ports 198 at a longitudinal area of the casing or BOP. As
previously discussed, the jetting housing 196 may be rotationally
retained on the outer housing 110 and tangential jetting ports 212
utilized to rotate the jetting housing 196 to clean a
circumferential area of the casing and/or BOP.
[0047] When a location of the casing and/or BOP has been cleaned,
fluid pressure through the axial through passage 124 may be
reduced. As the pressure is reduced to a pressure insufficient to
overcome the spring force, the spring 216 pushes the index housing
168 upward relative to the outer housing 110 to a third position,
shown in FIG. 7. The second outlet 128 through the outer housing
110 is closed when the index housing 168 is in the third
position.
[0048] The pressure may be increased again to a predetermined
pressure that is sufficient to overcome the spring force but that
is insufficient to deform the ball 250. This drives the index
housing 168 to a fourth position. From the fourth position, the
fluid pressure may be decreased again so that the spring 216 forces
the index housing 168 into another first position. Increasing the
pressure from this third position will force the index housing 168
into another second position in which the second outlet 128 is
again open and additional cleaning activities may be performed. If
such additional cleaning activities are not desired, from the
fourth position, the fluid pressure may be increased by an
additional amount sufficient to shear the ball 250 from the ball
seat 148. When the ball 250 has been sheared from the ball seat
148, the spring 216 will force the index housing 168 into another
first position and the jetting tool may be re-actuated by dropping
another ball 250. The sheared ball 250 is circulated through the
remainder of the jetting tool 100 and is caught by the ball catcher
122. As previously discussed, if recirculation of the fluid is
desired, the ball catcher 122 will retain any sheared balls 250
previously caught in the ball catcher 122.
[0049] Referring to FIG. 9, in another embodiment, a downhole
bypass valve 300 is used to selectively divert fluid that is
flowing down the drill string bore 302 to the annulus 304 between
the drill string and the casing 306 of a wellbore 308. The bypass
valve 300 includes an outer housing 310, a spring-loaded mandrel
368, and a cantilever-type ball seat collet assembly 410 defining a
tubular assembly having an inlet 406 and a first outlet 408.
[0050] The outer housing 310 defines an outer housing through bore
324 within which the spring-loaded mandrel 368 and the collet
assembly 410 are located. The outer housing 310 has a top sub 326
provided at a top end 312, wherein the top sub 326 includes a
threaded box 314 to couple to an upper drill string component 316.
The top sub 326 is coupled to a ported seal housing 328 at a lower
end 330. The ported seal housing 328 has one or more radially
extending ports 332 extending from the outer housing through bore
324 to the annulus 304, defining a second outlet. A swivel housing
334 is coupled to a lower end 336 of the ported seal housing 328.
As shown more clearly in FIG. 10a, the coupling of the swivel
housing 334 and the ported seal housing 328 provides an upper
shoulder 338 at the lower end 336 of the ported seal housing 328. A
lower shoulder 340, formed in the swivel housing 334, is spaced
apart from the upper shoulder 336 to form an inner recess 342
within which a swivel ring 344 is retained. The swivel ring 344
includes at least one indexing pin 346 extending radially into the
through bore 324 defined by the outer housing 310. While the swivel
ring 344 is axially retained by the upper and lower shoulders 338,
340, the swivel ring 344 is not rotationally retained to the outer
housing 310. Thus, the swivel ring 344 may rotate within the
confines of the upper and lower shoulders 338, 340. Returning to
FIG. 9, along a middle portion 350 of the swivel housing 334, a
spring housing 352 is coupled thereto. As shown more clearly in
FIG. 10c, a lower portion 354 of the swivel housing 334 protrudes
axially within a through bore 356 defined by the spring housing 352
and has a recess formation 358 in an inner surface 359 at its lower
end 360. The lower portion 354 of the swivel housing 334 is spaced
apart from the corresponding portion of the spring housing 352 such
that a small gap 362 is created. Within this small gap 362, a
spring sleeve 362 is coupled to the spring housing 352. As will be
explained below, the spring sleeve 364 is included primarily to aid
in the assembly and disassembly of the bypass valve 300. Returning
again to FIG. 9, the spring housing 352 is provided with external
threads 320 at lower end 318 to couple to a lower drill string
component 322.
[0051] As previously stated, the spring-loaded mandrel 368 is
located within the outer housing 310. The spring-loaded mandrel 368
includes an indexing mandrel 370 coupled at a lower end 372 to a
shoulder sub 374 to define a mandrel through bore 376. As shown in
FIG. 10b, the through bore 376 has a mandrel bore radius 378. A
bonded seal member 380 is located above a shoulder formation 382 in
the outer surface 384 of the indexing mandrel 370. A retaining ring
386 may be secured to the indexing mandrel 370 such that it is
spaced apart from the shoulder formation 382 to maintain the bonded
seal member 380 in a position near the upper end 387 of the
indexing mandrel 370. The bonded seal member 380 includes a pair of
resilient outer seals 388, 390, which seal the interface between
the inner surface 392 of the ported seal housing 328 and the outer
surface 394 of the bonded seal member 380. An o-ring 396 seals the
interface between an inner surface 398 of the bonded seal member
380 and the outer surface 384 of the indexing mandrel 370. Below
the shoulder formation 382, a recess 402 is formed in the outer
surface 384 of the indexing mandrel 370. An o-ring 404 seals the
interface between the outer surface 384 of the indexing mandrel 370
and the inner surface 392 of the ported seal housing 328 below the
recess 402. Returning to FIG. 9, an indexing groove 400 is formed
into the outer surface 384 of the indexing mandrel 370 between the
o-ring 404 and a lower end 372 of the indexing mandrel 370. The
indexing pin 346, coupled to the outer housing 310, is positioned
within the indexing groove 400. The function of the indexing groove
400 and the indexing pin 346 is described in greater detail
below.
[0052] The ball seat collet assembly 410 includes a collet member
412, a spring follower 414 and a spring 416. As will be described,
the collet assembly 410 has limited axial mobility within the
through bore 324 of the outer housing 310. The spring 416 is
located within the through bore 356 defined by the spring housing
352. A shoulder formation 418 in the inner surface 420 of the
spring housing 352 near the lower end 318 provides support to a
lower end 422 of the spring 416. As can be seen more clearly in
FIG. 10c, the spring follower 414 has a lower shoulder 424 that is
seated atop an upper end 426 of the spring 416. The collet member
412 has a lower end 428 that is seated atop an upper shoulder 430
of the spring follower 414. From the collet member lower end 428,
several cantilevered collet arms 432 extend upward. A collet head
434 is located at an upper end 436 of each collet arm 432. In the
position shown in FIG. 9, each collet head 434 is biased outward by
the corresponding cantilevered collet arm 432 to contact the inner
surface 359 of the lower portion 354 of the swivel housing 334. The
collet heads 434 form a collet through bore 438 having a collet
inner radius 440.
[0053] When the bypass valve 300 is assembled, the spring 416 is
lowered into the spring housing 352 and the spring follower 414 is
placed atop the spring 416. The swivel housing 334 couples to the
spring housing 352. However, the length of the spring 416 when
loaded only with the spring follower 414 would extend beyond the
lower end 360 of the lower portion 354 of the swivel housing 334
when the swivel housing 334 is coupled to the spring housing 352.
Instead of loading the spring 416 with the swivel housing 334 while
coupling to the spring housing 352, the spring sleeve 364 is
coupled to the spring housing 352 to preload the spring 416,
through the spring follower 414, against a lower shoulder 366. The
smaller size of the spring sleeve 364 makes it easier to couple to
the spring housing 352 while simultaneously preloading the spring
416. The larger swivel housing 334 may then be simply coupled to
the spring housing 352. When disassembling the bypass valve 300,
the spring sleeve 364 retains the spring 362 and spring follower
414 within the spring housing 352 while the swivel housing 334 is
removed.
[0054] In an alternative embodiment a jetting housing (not shown)
may be provided around the bypass valve 300. The jetting housing
displaces annular space when the bypass valve 300 is to be used in
a bore, such as that of a riser, having a sufficiently large inner
diameter that annular fluid velocity would be lost if the bypass
valve 300 were used alone. By reducing the annular area, fluid
velocity through the ports 332 into the annulus 304 may be
maintained at a rate that is effective for removing debris or
circulating fluid.
[0055] When lowered downhole on the drill string, the bypass valve
300 is in a first position, as depicted in FIG. 9. In this
position, the recess 402 of the indexing mandrel 370 is positioned
inside the ports 332. As depicted in FIG. 10c, the outer seals 388,
390 of the bonded seal ring 380 are located above the ports 332
while the o-ring 404 is positioned below the ports 332 to prevent
fluid communication between the through bore 376 and the annulus
304. Returning to FIG. 9, fluid may continue to flow through the
through bore 376 defined by the spring loaded mandrel 368 and the
through bore 356 defined by the spring housing 352. In the first
position, the collet inner radius 440 is slightly smaller than the
mandrel radius 378 (shown in FIGS. 10c and 10b, respectfully).
[0056] Referring to FIG. 11, when it is desired to actuate the
bypass valve 300, a ball 450 is dropped through the drill string
and circulated until it reaches the bypass valve 300. The ball 450
has a ball radius 452, which is less than the mandrel bore radius
378 and greater than the collet inner radius 440, thus permitting
the ball 450 to continue to circulate through the bypass valve 300
until it comes to rest atop the collet heads 434 of the collet
assembly 410. The ball 450 prevents further fluid flow through the
bore 438, 456 of the collet assembly 410, spring 416, and spring
housing 352. As the fluid pressure is increased, the collet
assembly 410 is pushed downward against the upward force of the
spring 416. The increased fluid pressure within the axial through
bore 376 and the lower pressure outside of the mandrel 368 causes
the spring loaded mandrel 368 to move downward as well. The
indexing groove 400 on the indexing mandrel 370 interfaces with the
indexing pin 346 to direct the position of the spring loaded
mandrel 368 within the outer housing 310.
[0057] The indexing groove path 462 is depicted in FIG. 15. When
the bypass valve 300 is in the first position, the indexing pin 346
is located in a first groove location 460. Referring to FIGS. 12
and 15, after the ball 450 is seated on the collet heads 434, fluid
pressure is increased until the collet assembly 410 is driven
downward against the force of the spring 416. The spring loaded
mandrel 368 is also pushed downward by the increased fluid pressure
within the axial bore 376. As the spring loaded mandrel 368 moves
downward within the outer housing 310, the indexing pin 346 follows
the indexing groove path 462 until it has reached a first groove
wall 464. Upon contacting the first groove wall 464, the indexing
pin 346 continues a path parallel to the first groove wall 464
until it has shouldered against second groove location 466. The
outer housing 310 is rotationally fixed by the drill string. The
spring loaded mandrel 368 is rotated within the outer housing 310
as the indexing pin 346 follows the indexing groove path 462. When
the indexing pin 346 is shouldered against the second groove
location 466, the bypass valve 300 is in a corresponding second
position, shown in FIG. 12.
[0058] In the second position, the ball 450 remains seated atop the
collet heads 434. The spring loaded mandrel 368 has moved a
sufficient distance downward to open the ports 332, providing fluid
communication from the through bore 324 to the annulus 304. So long
as the fluid flow remains sufficient to provide pressure to the
ball 450 and the collet assembly 410 to overcome the upward force
of the spring 416, the bypass valve 300 will remain in the second
position.
[0059] Referring to FIGS. 13 and 15, when the flow drops to below a
predetermined flow rate corresponding to a predetermined fluid
pressure, the spring 416 will push the collet assembly 410 upward.
The collet assembly 410 in turn pushes the spring loaded mandrel
368 upward. The indexing pin 346 continues to follow the indexing
groove path 462 and contacts a second groove wall 468. The indexing
pin 346 follows the incline of the second groove wall 468 to rotate
the spring loaded mandrel 368 within the outer housing 310 as it
continues to move upward until the indexing pin 346 shoulders
against a third groove location 470. When the indexing pin 346 is
in the third groove location 470, the bypass valve 300 is in a
corresponding third position, shown in FIG. 13.
[0060] In the third position, the ball 450 remains seated atop the
collet heads 434. The ports 332 remain open, providing fluid
communication from the through bore 324 to the annulus 304. In this
position, the fluid can be reverse circulated at any desired rate.
Circulation can be maintained up to a predetermined rate at which
the fluid pressure would overcome the spring force once again. In
the third position, multiple batches of various fluids can be
circulated, depending upon the viscosity and density of the fluids,
so long as the predetermined rate is not exceeded.
[0061] The fluid pressure may be increased to cycle the spring
loaded mandrel 368 to the second position, in which the indexing
pin 346 is shouldered against another second groove location 466.
Decreasing the fluid pressure again will return the spring loaded
mandrel 368 to the third position, wherein the indexing pin 346 is
shouldered against another third groove location 470. This cycle
may be continued until the indexing pin 346 has traversed the
indexing groove path 462 to shoulder against a final third groove
location 470, corresponding to the third position.
[0062] Referring to FIGS. 14 and 15, to close the bypass valve 300,
the fluid pressure may be increased when the indexing pin 346 is
shouldered against the final third groove location 470. As
previously described, as the fluid pressure is increased, the
collet assembly 410 and mandrel 368 are driven downward against the
force of the spring 416. This time, however, the indexing pin 346
is directed along the indexing groove path 462 until it shoulders
against a final groove location 472. The final groove location 472
corresponds to a fourth position of the spring loaded mandrel 368
that is farther downhole, relative to the outer housing 310, than
in the first, second, or third positions. In the fourth position,
the collet assembly 410 is driven downward against the force of the
spring 416 until the collet heads 434 are received into
corresponding recess formations 358 in the lower portion 354 of the
swivel housing 334. Once the collet heads 434 spring outward into
the recess formations 358, the collet inner radius 440 is enlarged
such that it is larger than the ball radius 452. The ball 450 is
then forced downward through the bore 438 of the collet assembly
310 and the bore 356 of the spring housing 352. The ball 450 will
be caught in a downstream ball catcher (not shown). When the ball
450 is released from the collet heads 434, the fluid pressure
counteracting the spring force is relieved and the spring 416
pushes the collet assembly 410 upward. The collet assembly 410 in
turn pushes the spring loaded mandrel 368 upward. The indexing
groove 400 and pin 346 interact to reposition the spring-loaded
mandrel 368 in the first position in which the ports 332 are closed
and from which the entire process may be performed again.
[0063] While the claimed subject matter has been described with
respect to a limited number of embodiments, those skilled in the
art, having benefit of this disclosure, will appreciate that other
embodiments can be devised which do not depart from the scope of
the claimed subject matter as disclosed herein. Accordingly, the
scope of the claimed subject matter should be limited only by the
attached claims.
* * * * *