Information
-
Patent Grant
-
6220360
-
Patent Number
6,220,360
-
Date Filed
Thursday, March 9, 200024 years ago
-
Date Issued
Tuesday, April 24, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Bagnell; David
- Hawkins; Jennifer M
Agents
- Kent; Robert A.
- Rahhal; Anthony L.
-
CPC
-
US Classifications
Field of Search
US
- 166 192
- 166 193
- 166 318
- 166 3324
- 166 373
- 166 386
-
International Classifications
- E21B2300
- E21B3312
- E21B3400
- E21B3410
-
Abstract
A ball drop tool, for dropping a ball to a ball seat located in a tool, or tool string therebelow. The ball drop tool has an upper end adapted to be connected to the lower end of the coiled tubing string. The ball drop tool includes a housing with a ball drop cage positioned therein. The ball drop cage has a rocker arm pivotally attached thereto. The rocker arm can be pivoted so that a lower end thereof extends radially inwardly into an opening and will hold a ball in the cage. The cage will move downwardly in the housing until the lower end of the rocker arm is retracted from the opening, which will allow the ball to pass downwardly through the ball drop housing so that it can be received in a ball seat in a tool therebelow.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a ball drop tool, and more particularly to a ball drop tool to be connected in a tool string lowered into a wellbore with coiled tubing.
In the drilling and completion of oil and gas wells, a wellbore is drilled into the subterranean producing formation or zone of interest. A string of pipe, e.g., casing, is typically then cemented into the wellbore. Oftentimes, a second string of pipe, commonly referred to as a liner, is attached at the lower end of the casing and extends further into the wellbore. Casing, when referred to herein, includes liners. A string of additional pipe, known as production tubing, is often lowered into the casing and/or the liner for conducting produced fluids out of the wellbore.
It is often necessary to lower downhole tools, such as packers or other tools into the casing, liner or production tubing to perform a desired operation. Many known downhole tools, such as but not limited to hydraulic disconnects, circulating subs and inflatable packers require a ball to be displaced down a tool string to engage a ball seat disposed in the tool. Typically, pressure is applied after the ball engages the seat to activate a mechanism in the tool. For example, with an inflatable packer, the ball may engage a seat to direct fluid into the inflatable elements of the packer, so that the packer will engage the casing, liner or production tubing. The foregoing are merely examples and there are a number of known tools that utilize and require a ball to engage a ball seat so that pressure can be applied in the tool above the seat to activate a mechanism in the tool string.
Coiled tubing is rapidly becoming a popular conveyance method for downhole tools, and the use of dropped balls to engage a seat in a tool lowered into the wellbore with coiled tubing is becoming more and more common. When coiled tubing is utilized to lower a tool into a wellbore, and it is necessary to drop a ball to engage a seat in the tool, the ball normally is manually inserted into the surface plumbing for the coiled tubing, so that the ball enters the coiled tubing at, or near the end of the tubing connected to the surface plumbing. The ball therefore enters the coiled tubing so that it must be pumped through the coiled tubing wraps on the reel, until it passes over a gooseneck which is utilized in connection with the coiled tubing. Pumping then continues for a period of time to insure that the ball has made its way through the coiled tubing to the seat in the downhole tool. Although such a method works in many circumstances, there are several drawbacks to this method.
The method described above for displacing a ball through coiled tubing is time-consuming and costly. It requires the usage of a large volume of fluid since at least one displacement volume of the coiled tubing is needed to get the ball around the wraps and to the downhole tool. Occasionally, balls are caught in the coiled tubing and never make it to the tool. For example, when small diameter balls are used in large coiled tubing, it is difficult to achieve a fluid velocity which will carry a small diameter ball through the wraps on the reel.
In addition, there are times when downhole devices above the ball seat have restrictions which would prevent a ball from passing therethrough to the ball seat in the tool. For example, filter screens are often run downhole to keep debris from plugging off small passages in the tools below. Actuating balls cannot pass through the screens. Likewise, it is possible that a tool having a small diameter would be positioned above the ball seat and thus would prevent the ball from passing therethrough. The present invention addresses the above needs by providing a downhole ball drop tool that can be positioned in the tool string below the coiled tubing and if necessary below any tools with restrictive diameters, and above the seat in the tool such that the ball does not have to pass through the coiled tubing wraps.
SUMMARY OF THE INVENTION
The present invention is a ball drop tool for use with coiled tubing which provides a method for dropping a ball into a downhole tool to engage a ball seat in the tool without the necessity of displacing the ball through the coiled wraps in a reeled coiled tubing. The ball drop tool comprises a ball drop housing having an upper end adapted for connection to a length of coiled tubing. The housing has a longitudinal opening therethrough and has a ball drop cage disposed therein. The ball drop cage has a closed upper end and an open lower end. A ball is disposed in the ball drop cage. A rocker arm having an upper end and a lower end is pivotally connected to the ball drop cage.
The ball drop tool may be connected to a lower end of the length of coiled tubing and lowered into the wellbore as part of a tool string having a ball seat therein. The ball drop tool has a retaining position and a releasing position. In the retaining position, the rocker arm is rotated such that a lower end of the rocker arm is positioned in an opening defined by the ball drop cage. The ball is trapped between the rocker arm and the closed upper end of the ball drop cage so that it cannot pass downwardly into the ball seat therebelow. The tool string can be lowered into a wellbore and once it has reached a selected location, fluid flow can be increased so that a flow, or pressure sufficient to begin to urge the ball drop cage downwardly in the ball drop housing is reached. The fluid will act on the upper cap and will also act on the balls through openings defined in the upper cap to cause the ball drop cage to begin to move downwardly in the ball drop housing. The rocker arm will pivot so that the lower end thereof is retracted from the opening defined by the ball drop cage. Once this occurs, the ball will be released and allowed to pass downwardly through the ball drop tool and into the tool having the ball seat disposed therein. Pressure can then be increased to activate any mechanism associated with the ball drop seat and ball.
Numerous objects and advantages of the invention will become apparent to those skilled in the art when the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate such embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a schematic illustration of a cased well having a string of production tubing disposed therein and having a length of coiled tubing with a tool string including the downhole ball drop tool of the present invention inserted into the well by a coiled tubing injector and truck mounted reel.
FIGS. 2
,
3
and
4
show cross sections of the ball drop tool of the present invention in different positions having actuating balls disposed therein.
FIG. 5
shows a partial section of the end view of the ball cage of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
After a well has been drilled, completed and/or placed in production, it is often necessary to perform any number of procedures therein such as but not limited to perforating, setting plugs, setting cement retainers, spotting permanent packers and the like. Such procedures are often carried out by utilizing coiled tubing. Coiled tubing is a flexible tubing, which can be stored on a reel when not being used. When used for performing well procedures, the tubing is passed through an injector mechanism, and a well tool is connected to the end thereof. A variety of tools may be connected in a tool string lowered in the well on the coiled tubing, and very often one of the tools will have a ball seat for receiving an actuating ball. Once the ball has engaged the seat, pressure can be increased to activate a mechanism in the tool string. The use of dropped balls through coiled tubing, and the use of ball seats in connection with a variety of tools, including but not limited to hydraulic disconnects, inflatable packers, hydraulic setting tools and pressure firing heads is common and is well known.
The injector mechanism pulls the tubing from the reel, straightens the tubing and injects it through a seal assembly at the wellhead, often referred to as a stuffing box. Typically, the injector mechanism injects thousands of feet of the coiled tubing with the well tool connected at the bottom end thereof into the casing string or the production tubing string of the well. A fluid, most often a liquid such as salt water, brine or a hydrocarbon liquid, may be circulated through the coiled tubing for operating well tools or for other purposes. The coiled tubing injector at the surface is used to raise and lower the coiled tubing and the well tool or tools during the service procedure and to remove the coiled tubing and well tools as the tubing is rewound on the reel at the end of the procedure.
Presently, when a tool having a ball seat is lowered into the coiled tubing, the ball is inserted into the surface plumbing and must be circulated through some or all of the coiled tubing wraps on the reel, out the bottom end of the coiled tubing and into the tool and the ball seat. The present invention provides a method and apparatus for positioning a ball between the bottom end of the coiled tubing and the ball seat.
Referring now to
FIG. 1
, a well
10
is schematically illustrated along with a coiled tubing injector
12
and a truck mounted coiled tubing reel assembly
14
. Well
10
includes a wellbore
16
having a string of casing
18
cemented therein in the usual manner. A string of production tubing
20
is also shown installed in well
10
within casing string
18
. Production string
20
may be made up of a plurality of tubing sections
22
connected by a plurality of joints or collars
24
in a manner known in the art.
A length of coiled tubing
26
is shown positioned in production tubing string
20
. A tool string
27
including a downhole tool
28
is connected to coiled tubing
26
. Tool
28
has a ball seat
29
therein for receiving a ball. The ball drop tool
30
of the present invention is generally designated in
FIG. 1
by the numeral
30
. Ball drop tool
30
may be connected to the lower end of coiled tubing
26
with an adapter
31
or other tool or joint connector. Other well tools may be attached above or below tool
28
.
Coiled tubing
26
is inserted into well
10
by injector
12
through a stuffing box
32
attached to the upper end of tubing string
20
. Stuffing box
32
functions to provide a seal between coiled tubing
26
and production tubing string
20
whereby pressurized fluids within well
10
are prevented from escaping to the atmosphere. A circulating fluid removal conduit
34
having a shutoff valve
36
therein is sealingly connected to the top of casing string
18
. Fluid circulated into well
10
through coiled tubing
26
is removed from the well through conduit
34
and valve
36
and routed to a pit, tank or other fluid accumulator.
Coiled tubing injector
12
is of a kind known in the art and functions to straighten coiled tubing
26
and inject it into well
10
through stuffing box
32
as previously mentioned. Coiled tubing injector
12
comprises a guide mechanism
38
, commonly referred to as a gooseneck, having a plurality of internal guide rollers
40
therein and a coiled tubing drive mechanism
42
which is used for inserting coiled tubing
26
into well
10
, raising the coiled tubing or lowering it within the well, and removing the coiled tubing from the well as it is rewound on reel assembly
14
.
Truck mounted reel assembly
14
includes a reel
50
on which coiled tubing
26
is wound. A guide wheel
52
is provided for guiding coiled tubing
26
on and off reel
50
. A conduit assembly
54
is connected to the end of coiled tubing
26
on reel
50
by a swivel system (not shown). A shutoff valve
56
is disposed in conduit assembly
54
, and the conduit assembly is connected to a fluid pump (not shown) which pumps fluid to be circulated from the pit, tank or other fluid communicator through the conduit assembly and into coiled tubing
26
. Typically if an actuating ball is to be dropped without the use of the ball drop tool
30
of the present invention, the ball may be inserted in the piping between the coiled tubing and the shutoff valve
56
. Balls may also be introduced upstream of the valve and pumped therethrough. In either case, balls introduced in this manner must pass through the wraps of coiled tubing on the coiled tubing reel.
A fluid pressure sensing device and transducer
58
may be connected to conduit assembly
54
by connection
60
, and the pressure-sensing device may be connected to a data acquisition system
46
by an electric cable
62
. As will be understood by those skilled in the art, data acquisition system
46
may function to record the surface pressure of fluid being pumped through the coiled tubing. Other known methods may also be used to record fluid pressure.
Referring now to
FIGS. 2-5
, the details of ball drop tool
30
will be discussed. Ball drop tool
30
which may also be referred to as a ball drop assembly
30
, comprises a ball drop housing
70
having a ball drop cage
72
movably disposed therein. Ball drop cage
72
has a central opening
69
defined by a bore
71
. Ball drop tool
30
has at least one, and preferably three rocker arms
74
. Rocker arms
74
are pivotably connected to ball drop cage
72
. Each rocker arm
74
has a thickness
73
and a length
75
.
The ball drop assembly
30
of the present invention may be utilized with one or more balls, and the embodiment shown in
FIGS. 2-4
has two actuating balls comprising a first or lower ball
76
and a second or upper ball
78
. In the embodiment shown, ball
76
is smaller than ball
78
. Balls of the same size may be used depending on the configuration of the tool and the ball seats to be utilized. Additional balls could be added simply by lengthening the tool
30
and placing balls therein. Ball drop cage
72
is movable from a retaining position
80
, which may be referred to as a first retaining position shown in
FIG. 2
, to a releasing position
82
as shown in FIG.
4
. The position shown in
FIG. 3
may be referred to as a second retaining position
81
. Rocker arm
74
has corresponding first and second retaining positions
84
and
85
as seen in
FIGS. 2 and 3
and a releasing position
86
as shown in FIG.
4
.
Housing
70
has an upper end
88
, a lower end
90
, an outer surface
92
and an inner surface
94
. Threads
96
are defined on inner surface
94
at the upper end of housing
70
. Housing
70
is thus adapted to be connected to the lower end of coiled tubing
26
with an adapter, joint or other tool which may be connected to ball drop assembly
30
at threads
96
and connected to coiled tubing
26
, thus connecting ball drop assembly
30
to coiled tubing
26
. Threads
100
are defined on the inner surface
94
of housing
70
at the lower end thereof and so that tool
30
may be connected to a tool, joint, or other threaded member therebelow. Ball drop assembly
30
is therefore adapted to be connected to the lower end of coiled tubing
26
and to be connected in tool string
27
.
Housing
70
has a first bore
102
, a second bore
104
and a third bore
106
. Second bore
104
has a smaller diameter than first bore
102
and is positioned radially inwardly therefrom. Third bore
106
has a diameter greater than second bore
104
and less than first bore
102
. Third bore
106
is thus positioned radially outwardly from second bore
104
and radially inwardly from first bore
102
. First or upper and second or lower cavities
108
and
110
respectively are defined in first bore
102
. First cavity
108
has first or upper and second or lower angular sides
112
and
114
connected by a base or flat portion
116
. Second cavity
110
is defined by first or upper and second or lower angular sides
118
and
120
connected by a flat or base portion
122
therebetween. Cavities
108
and
110
are spaced apart from one another in bore
102
such that they define a flat or fulcrum portion
124
. Fulcrum portion
124
defines a portion of bore
102
. Angular side
120
extends radially inwardly to bore
104
and thus may include an angular transition portion
126
. A downward facing shoulder
128
is defined by and extends between second and third bores
104
and
106
respectively.
Ball drop cage
72
has an upper end
129
, a lower end
131
, and essentially comprises a collet comprising a collet body
130
, and a plurality of collet fingers
132
having a first end
134
and a second end
136
extending therefrom. Upper end
129
is closed to prevent balls disposed therein from passing upwardly in the tool. Lower end
131
is open to allow the passage of balls therethrough. A plurality of collet heads
138
are defined at second end
136
of collet fingers
132
. Preferably, ball drop cage
72
comprises eight collet fingers. A first outer or collet body diameter
140
is defined on collet body
130
. Collet fingers
132
define a collet finger, or second outer diameter
142
positioned radially inwardly from first outer diameter
140
. Collet heads define a collet head diameter or third outer diameter
144
which extends radially outwardly from second or finger outer diameter
142
. An upward facing shoulder
146
is defined by and extends between second and third outer diameters
142
and
144
on ball drop cage
72
. A cap
148
is defined at the upper end
150
of collet body
130
which also comprises upper end
129
of ball drop cage
72
. Cap
148
has a plurality of openings
152
defined therein for allowing flow therethrough.
Slots
154
are defined in collet body
130
for receiving rocker arms
74
. A width
156
and length
158
of slot
154
are greater than thickness
73
and length
75
of rocker arms
74
. Openings
160
are defined in collet body
130
and intersect slots
154
. Rocker arms
74
have openings
162
. Openings
160
and
162
are for receiving pins, which are preferably self-locking pins
164
. Rocker arms
74
are thus pivotably attached to ball drop cage
72
, and preferably to the collet body portion
130
thereof.
Referring now to
FIG. 2
, ball drop cage
72
is received in ball drop housing
70
such that collet heads
138
are positioned in third bore
106
. Third bore
106
has an upper end
166
which is defined by shoulder
128
and a lower end
168
. A groove
170
is defined in bore
106
at the lower end thereof and has a retaining ring
172
received therein. A washer
174
is disposed in bore
106
and rests on retaining clip
172
. A spring
176
is disposed in bore
106
and, as shown in
FIG. 2
, engages washer
174
and collet heads
138
. Spring
176
thus biases ball drop cage
72
upwardly so that the collet heads
138
engage shoulder
128
to hold ball drop cage
72
in its first retaining position
80
.
Rocker arms
74
have a first or upper ends
182
and second or lower ends
184
. A first, or upper radially inwardly extending foot
186
is disposed at upper end
182
and a second or lower radially inwardly extending foot
188
is disposed at lower end
184
of each rocker arm
74
. In retaining position
80
, rocker arms
74
are rotated such that lower ends
184
thereof are rotated into opening
71
and engage first or lower ball
76
. Upper ends
182
of rocker arms
74
are rotated radially outwardly and are received in upper cavity
112
.
The operation of the invention is apparent from the drawings. Coiled tubing
26
is passed through tubing injector
12
. Tool string
27
which includes ball drop tool
30
is connected to the lower end of coiled tubing
26
. Ball drop tool
30
may be connected to the lower end of coiled tubing
26
with an adapter, joint or other tool or threaded connection therebetween. Ball drop tool
30
is thus positioned between the end of coiled tubing
26
and ball seat
29
disposed in downhole tool
28
, which is also connected in tool string
27
. Ball drop tool
30
is lowered into the well, along with the remainder of tool string
27
until a selected location in the well is reached. If desired, fluid may be circulated through the tool since ball drop tool
30
allows flow therethrough around ball drop cage
72
and through openings
152
.
Once the selected location is reached, flow rate can be increased to a sufficient rate such that the pressure acting across cap
148
of ball drop cage
72
and the balls will overcome the force of spring
176
and urge ball drop cage
72
downwardly. The increase in flow rate will act on the balls which will cause rocker arms
74
to pivot to the position shown in
FIG. 3
which is referred to as second retaining position
81
since the actuating balls will not be released in that position. Continued flow will cause cage
72
to slide downward. Flat
124
acts similarly to a fulcrum, so that as cage
72
continues to slide downward, rocker arms
74
will pivot about pin
164
and rotate about flat
124
until lower foot
188
rotates radially outwardly and is received in lower cavity
110
as shown in FIG.
4
. First ball
76
is released and fluid flow therein will displace ball
76
downwardly until it reaches ball seat
29
. Ball drop cage
72
and rocker arm
74
can thus be referred to as a hydraulically actuated releasing means. Once ball
76
reaches seat
29
, pressure in the tool string can be increased to activate a desired mechanism associated with the ball seat, including those set forth above, or any other tool or mechanism that requires an increase in pressure, or a redirection of flow caused by a ball engaging a ball seat.
As is apparent from
FIG. 4
, which shows the sleeve in its releasing position, if a second or more balls are utilized, the balls are prevented from flowing downwardly by upper end
182
of rocker arm
74
. Once flow is slowed, or stopped to decrease pressure in the tool string, spring
176
will urge ball drop cage
72
back to its retaining position and, if a second ball is being utilized such as ball
78
, the ball will then take the position which was occupied by first ball
76
as shown in FIG.
2
and is ready to be dropped.
If a second ball is used, it may be necessary to increase the pressure to a sufficient amount to discharge the first ball and the first ball seat from the tool string or to open additional flow ports to allow flow through the tool so that the cage
72
can be moved to its releasing position. A second ball seat in the tool string can then be engaged by second ball
180
. Because first ball
76
is preferably smaller than ball
78
, it can pass through the seat which will be engaged by ball
78
. Once the first ball and ball seat have been removed or flow ports opened, flow can then be decreased so that cage
72
moves to its first retaining position
80
and is ready to drop second ball
78
. To drop second ball
78
, the process is simply repeated and flow is increased to move the cage from retaining position
80
to releasing position
82
and to displace the ball
78
downwardly until it is received in a second ball seat. Once second ball
78
engages the second ball seat, pressure can again be increased to activate a mechanism associated with the second ball seat.
Although ball drop tool
30
is shown disposed in a production tubing, it is apparent that the tool can be utilized in production tubing, or in the casing itself. It will be seen, therefore, that the ball drop tool of the present invention is well adapted to carry out the ends and advantages mentioned, as well as those inherent therein. The invention can be utilized with any tool which requires that a ball be dropped to engage a ball seat therein and is not limited by any of the specific examples provided. While presently preferred embodiments of the apparatus have been described for the purposes of this disclosure, numerous changes in the arrangement and construction of parts may be made by those skilled in the art. All such changes are encompassed within the spirit and scope of the appended claims.
Claims
- 1. A method of dropping a ball through a tool string to engage a ball seat located in a downhole tool, the method comprising:(a) providing said tool string with said downhole tool; (b) placing an actuating ball in said tool string above said ball seat; (c) lowering said tool string, including said actuating ball into a wellbore with coiled tubing; and (d) releasing said ball after said tool string has been lowered so that it engages said ball seat.
- 2. The method of claim 1 wherein said placing step comprises releasably positioning said actuating ball in said tool string above said ball seat.
- 3. The method of claim 1 wherein said releasing step comprises:displacing fluid into said tool string at a selected flow rate to cause said actuating ball to release and be displaced downwardly to said ball seat.
- 4. The method of claim 1, further comprising displacing a fluid through said tool string around said actuating ball prior to said releasing step.
- 5. The method of claim 1 wherein step (b) comprises placing first and second actuating balls in said tool string, said tool string having first and second ball seats below said actuating balls, and step (d) comprises releasing said first ball to engage said first ball seat, the method further comprising:(e) increasing pressure in said tool string to activate a first mechanism operably associated with said first ball seat; (f) after step (e), increasing said pressure to open a flow path through said tool string; and (g) releasing said second ball to engage said second ball seat.
- 6. The apparatus of claim 5 further comprising:(h) increasing pressure in said tool to activate a second mechanism operably associated with said second ball seat after said second actuating ball engages said second ball seat.
- 7. The method of claim 1 further comprising:(e) increasing pressure in said well to activate a mechanism operably associated with said ball seat after said actuating ball engages said ball seat.
- 8. The method of claim 1 wherein said placing step comprises:placing said actuating ball in a ball drop housing; and threadedly connecting said ball drop housing in said tool string above said ball seat.
- 9. A method of actuating a mechanism in a downhole tool string, said downhole tool string having a ball seat for receiving an actuating ball, the method comprising:releasably positioning said ball in said tool string between a lower end of a length of coiled tubing and said ball seat; lowering said tool string into said well with said coiled tubing; releasing said actuating ball so that it engages said ball seat; and increasing pressure in said tool string to actuate said mechanism.
- 10. The method of claim 9, wherein said releasing step comprising displacing fluid at a predetermined rate to cause said actuating ball to release to said ball seat.
- 11. The method of claim 9, said positioning step comprising:providing a ball drop housing; locating said actuating ball in said ball drop housing; and connecting said ball drop housing in said tool string between the lower end of said coiled tubing and said ball seat.
- 12. The method of claim 11, said ball drop housing having a ball drop cage for releasably retaining said actuating ball therein, said cage having a retaining position and a releasing position, said releasing step comprising moving said cage in said housing from said retaining to said releasing position to release said actuating ball.
- 13. The method of claim 12, said releasing step comprising hydraulically moving said cage to said releasing position.
- 14. A ball drop apparatus for use in a tool string lowered into a well, the tool string having a ball seat therein for receiving an actuating ball, the ball drop apparatus comprising:an outer housing adapted to be connected in said tool string; and the actuating ball releasably disposed in said housing, said housing having a flow path therethrough for allowing flow around said ball when said ball is disposed therein.
- 15. The ball drop apparatus of claim 14, further comprising:a ball drop cage disposed in said housing, said actuating ball being disposed in said ball drop cage, said cage having a cap at its upper end and having an open lower end and being movable from a retaining position wherein said ball is retained in said cage to a release position wherein said ball is released so that the ball can be displaced downwardly to said ball seat.
- 16. The apparatus of claim 15 wherein fluid flow through said housing at a selected rate causes said cage to move from its retaining to its release position.
- 17. The apparatus of claim 15 further comprising a rocker arm pivotally attached to said ball drop cage, wherein said rocker arm engages said actuating ball to retain said actuating ball when said cage is in its retaining position.
- 18. The apparatus of claim 17, wherein said rocker arm rotates to release said ball when said cage moves to its release position.
- 19. The apparatus of claim 15 wherein said cap has a plurality of openings for allowing flow therethrough.
- 20. The apparatus of claim 15, further comprising biasing means for biasing said cage to the retaining position.
- 21. The apparatus of claim 20, wherein said biasing means comprises a spring disposed in said housing below a lower end of said cage.
- 22. The apparatus of claim 21 wherein fluid is displaced at a sufficient rate into said outer housing to overcome a spring force of said spring to move said cage from said retaining to said release position.
- 23. The apparatus of claim 14 wherein said housing is adapted at upper and lower ends thereof to be threadedly connected in said tool string.
- 24. The apparatus of claim 14, said housing having first and second balls releasably disposed therein, wherein said first ball may be released and said second ball retained in said housing and released at a selected time thereafter.
- 25. The apparatus of claim 14, said ball being releasable in response to a flow of fluid through said ball drop tool.
- 26. The ball drop apparatus of claim 14, said outer housing adapted to be connected in said tool string below a lower end of a coiled tubing used to lower said tool string into said well.
- 27. A ball drop apparatus for use with a well tool lowered into a well on a length of coiled tubing, the tool having a ball seat receiving an actuating ball, the ball drop apparatus comprising:a housing positioned between a lower end of said coiled tubing and said ball seat; and the actuating ball releasably disposed in said housing.
- 28. The apparatus of claim 27, wherein fluid flow through said housing at a selected flow rate releases said actuating ball from said housing.
- 29. The apparatus of claim 27 further comprising:a ball cage movably disposed in said housing, said actuating ball being disposed in said cage, said cage being movable from a retaining position wherein said ball is retained in said cage and a release position wherein said actuating ball is released from said cage and passes through said housing to engage said ball seat.
- 30. The apparatus of claim 27, said housing and ball defining a flow path therebetween so that fluid may be circulated therethrough prior to said actuating ball being released.
- 31. The apparatus of claim 30, wherein increasing a fluid flow at a selected rate through said housing releases said actuating ball therefrom.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
1518865 |
McKissick |
Dec 1924 |
|
4491177 |
Baugh |
Jan 1985 |
|